| Clinical Significance In the healthy individual, almost all of the glucose filtered by the renal glomerulus is reabsorbed in the proximal convoluted tubule. The amount of glucose reabsorbed by the proximal tubule is determined by the body's need to maintain a sufficient level of glucose in the blood. If the concentration of blood glucose becomes too high (160-180 mg/dL), the tubules no longer reabsorb glucose, allowing it to pass through into the urine. It is important to note that glucose may appear in the urine of healthy individuals after consuming a meal that is high in glucose. Fasting prior to providing a sample for screening eliminates this problem. | View Page |
| Three Kinds of Ketones When the body breaks down fat for energy, three intermediate products are formed. These products, collectively referred to as ketones, are acetone, acetoacetic acid, and beta-hydroxybutyric acid. Normally, the body gets the energy it needs from carbohydrates in the diet. However, stored fat is broken down and ketones are produced and appear in the urine if the diet does not contain enough carbohydrate to supply the body with glucose for energy or if the body cannot use glucose properly. | View Page |
| Ketone Bodies Ketone bodies are usually absent in urine, but low levels may be detected during conditions of physiological stress such as fasting, rapid weight loss, frequent strenuous exercise or prolonged vomiting. The presence of ketones in these situations is due to either inadequate intake or increased loss of carbohydrates. High levels of ketones are present in the urine of individuals with uncontrolled diabetes. In diabetes the ketones are present because the body's ability to metabolize carbohydrates is defective. | View Page |
| Clinical Significance of Positive Urine Ketone Result Ketone bodies are usually absent in urine. The presence of ketones in the urine probably indicates that the body is using fats rather than carbohydrates for energy. High levels of ketones may be present in the urine of individuals with uncontrolled diabetes because the body's ability to metabolize carbohydrates is defective. Detecting the presence of ketones in the urine is a valuable aid to managing and monitoring individuals with diabetes mellitus. Ketonuria is an indication that the insulin dose needs to be increased. Electrolyte imbalance and dehydration occur when ketones accumulate in the blood. If these conditions are not corrected by adjusting the dose of insulin, the patient may develop ketoacidosis and ultimately diabetic coma. Low levels of ketones may be detected during conditions of physiological stress such as fasting, rapid weight loss, frequent strenuous exercise or prolonged vomiting. The presence of ketones in these situations is due to either inadequate intake of carbohydrates or increased loss of carbohydrates. | View Page |
| MIC susceptibility tests should also be performed against other select beta lactam antibiotics on important S. pneumoniae isolates from blood cultures and other sterile body fluids. | View Page |
| Clinical isolates of Escherichia coli and Klebsiella pneumoniae may possess ESBL activity. Therefore, clinical laboratories should be screening all clinically significant isolates of these two species. | View Page |
| Case History A 63 year old man was seen in the emergency room with the complaints of sudden onset of fever, chills, and abdominal pain, accompanied by mild diarrhea. The blood pressure was 140/84, the pulse rate 82/minute, and the body temperature 39.8C. A blood sample was drawn for a complete blood count, and a blood culture.A second blood culture was drawn from the opposite arm, with 10 ml of blood being placed into each an aerobic and an anaerobic bottle, following customary practice.The complete blood count revealed a hemoglobin of 15.8 mg/dl, a hematocrit of 45%, and a white blood count of 4.2/L. The neutrophils were 39%, lymphocytes 45%, monocytes 10%, eosinophils 4% and basophils 2%. The platelet count was 255/L. The patient was admitted to the hospital for further work-up and empiric antibiotic therapy.Within 24 hours after admission, the body temperature had decreased to 38.2C, although the mild diarrhea persisted.A stool toxin test for Clostridium difficile was negative and neither enteric pathogens nor Campylobacter species were recovered in stool culture after 24 hours incubation. Fecal neutrophils were not seen on direct examination.
The anaerobic blood culture became positive 36 hours after inoculation. | View Page |
| Review 1 Francois P. Vaudaux P. Foster TJ. Lew DP.:
Host-bacteria interactions in foreign body infections.
Infection Control & Hospital Epidemiology. 17:514-20, 1996Persistent staphylococcal infections are a major medical problem, especially when they occur on implanted materials or intravascular catheters.This review describes some of the recently discovered molecular mechanisms of Staphylococcus aureus attachment to host proteins coating biomedical implants.These interactions involve specific surface proteins, called bacterial adhesins, that recognize specific domains of host proteins deposited on indwelling devices, such as fibronectin, fibrinogen, or fibrin.Elucidation of molecular mechanisms of S. aureus adhesion to the different host proteins may lead to the development of specific inhibitors blocking attachment of S. aureus, which may decrease the risk of bacterial colonization of indwelling devices. | View Page |
| Review 3 Ladhani S. Joannou CL. Lochrie DP. Evans RW. Poston SM.:
Clinical, microbial, and biochemical aspects of the exfoliative toxins causing staphylococcal scalded-skin syndrome.
Clinical Microbiology Reviews. 12:224-242, 1999The exfoliative (epidermolytic) toxins of Staphylococcus aureus are the causative agents of the staphylococcal scalded-skin syndrome (SSSS), a blistering skin disorder that predominantly affects children. Clinical features of SSSS vary along a spectrum, ranging from a few localized blisters to generalized exfoliation covering almost the entire body.The toxins act specifically at the zona granulosa of the epidermis to produce the characteristic exfoliation, although the mechanism by which this is achieved is still poorly understood.Despite the availability of antibiotics, SSSS carries a significant mortality rate, particularly among neonates with secondary complications of epidermal loss and among adults with underlying diseases. | View Page |
| Specimens Serum and plasma are the most common clinical specimens used for electrophoresis applications. Urine and cerebrospinal fluids (CSF) are also suitable. Other body fluids such as pleural fluid and pericardial fluid are analyzed less frequently. Some specimens require pretreatment before electrophoresis. Low concentrations of proteins normally in urine and CSF are concentrated in order to have enough proteins for detectable separations. Some body fluids require removal of pigments, salts, and other compounds that interfere with electrophoresis or the detection of separated solutes. In molecular diagnostic testing of DNA and RNA, the nucleic acids must first be isolated from the specimen and then purified before separation with electrophoresis. | View Page |
| Currently there has been a revitalization in the clinical usage of electrophoresis. Previously, methods were primarily used to separate proteins in blood and other body fluids. From the following statements, select the statements that correctly describe newer applications of electrophoresis. | View Page |
| Electroendosmosis With a pH 8.0-9.0 used for protein electrophoresis, proteins take on a negative charge, that is a negative ion cloud forms. As the negative ion cloud migrates to the anode, the proteins are pulled to the anode. Several gels used routinely for protein electrophoresis attract positive ions from the buffer and form a positive ion cloud. This ion cloud moves in the opposite direction to the cathode. This phenomenon is called electroendosmosis or endosmosis.The tension created by these oppositely moving ion clouds can affect the movement of sample macromolecules. The migration of some proteins can be slowed, some proteins can become immobile, and other proteins are pushed toward the cathode. Many protein electrophoresis methods take advantage of this tension and use it to achieve better separation of protein bands. The gamma globulin band in serum, urine, and other body fluids will separate more sharply by being pushed to the cathode and will appear behind the point of sample application. | View Page |
| Resurgence of Electrophoresis Traditionally most clinical laboratory electrophoresis utilizes methods that separate and identify proteins in serum, urine, CSF, and some other body fluids. Most studies are for detecting serum protein abnormalities and gathering more information about gammopathies.In recent years, there has been a resurgence in electrophoresis use and methods. Development of automated methods has enhanced this. The evolution of numerous molecular diagnostic investigations and research in proteomics have also augmented electrophoresis.Applications of two-dimensional electrophoresis discussed the use of electrophoresis in proteomics. Electrophoresis and molecular diagnostics, blotting techniques, and current uses of CE in molecular diagnostics will be discussed now. | View Page |
| Atherosclerosis continued If a plaque ruptures it will expose sub-endothelial tissue to blood cells and in so doing stimulate the formation of a clot. The clot is the body's attempt to seal off the crack but the clot itself can cause further obstruction to blood flow. This sudden increase in the blockage caused by the raised ruptured plaque and associated clot can transform a mild blockage into a critical one within a matter of hours. If it occurs within the blood vessels of the heart, the decrease in blood flow leads to severe and prolonged chest pain known as unstable angina. Such a patient is at obvious risk for a myocardial infarct should the blockage become any worse.Atherosclerosis typically begins in early adolescence, and is found in most major arteries but since it is asymptomatic during the early half of life we need cardiovascualr risk markers to help assess patient risk. If an at-risk patient is identified early, the hope is that medication, lifestyle changes or medical procedures can be used to avert a serious cardiovascular event. So, although the vast majority of us have some degree of atherosclerosis, risk markers can help identify those among us who are in more imminent danger or who have increased risk of an adverse cardiovascular event. | View Page |
| Atherosclerosis Atherosclerosis is a clogging, narrowing and hardening of the body's large and medium-sized blood vessels. Atherosclerosis can lead to hypertension, stroke, myocardial infarction (heart attack), renal problems, etc. Not surprisingly, cardiovascular risk markers tend to reflect a person's degree of atherosclerosis.Atherosclerosis is actually a chronic inflammatory response within the walls of arteries. Small lipoproteins like LDL are able to diffuse through the endothelial wall of blood vessels and accumulate. The inflammatory component of atherosclerosis results from the migration of leukocytes (mainly macrophages) that enter the blood vessel walls. These macrophages seek to remove the deposited LDL as well as intermediate-density lipoproteins (IDL). As macrophages phagocytose these lipoproteins, they become foam cells that get trapped in the endothelial space. This eventually leads to "hardening" or "furring" of the arteries and plaque formation. Arteriosclerosis is a general term describing any hardening (loss of elasticity) of medium or large arteries whereas atherosclerosis is a hardening of an artery specifically due to plaque. The risk to patients with significant atherosclerosis is that eventually a narrowing of the artery (stenosis) can cause a reduction in oxygen delivery to tissues and plaque rupture can lead to an acute coronary event. | View Page |
| Transport of Lipophilic Substances Many lipophilic substances, including fat-soluble vitamins, cholesterol, and triglycerides are essential for life. The body needs to be able to absorb and transport these substances. However, lipophilic substances are not water-soluble, and, since blood is aqueous, this presents a challenge. The body addresses this need by using 'carriers' which can bind or sequester lipophilic molecules to aqueous 'vehicles' and thus transport them through the aqueous environment of the blood. Small lipid-soluble hormone molecules like estrogen, testosterone or cortisone are carried through the blood by binding to carrier proteins. Cholesterol and triglycerides are carried through the body in small spherical particles which trap the lipophilic molecules in their centers. These particles have an outer shell that is polar on the surface so that the particles are soluble in the blood but they have a lipophilic core which can hold fat-soluble molecules. | View Page |
| Apolipoproteins Lipoproteins differ in size and density as well as in their content (what they tend to carry). They also can differ in their origination (where they are made). Another significant difference between lipoprotein molecules is the proteins they have on their surfaces. These proteins, known as apolipoproteins, are the major identifying characteristics of a lipoprotein. There are many different apolipoproteins and we are continually learning more about them. Apolipoproteins have multiple roles. One role is that these amphipathic (detergent-like) proteins increase the overall solubility of the lipid particle, helping it to dissolve in the aqueous environment of the blood. Apolipoproteins can also function as enzyme co-factors (receptor ligands) and facilitate the transfer of their lipid cargo to specific cells. Thus, the apoliproteins are the smart or working-end of the lipoprotein particle. The apolipoproteins dictate where the particles will dock and where they can bind, and in so doing the apolipoproteins regulate lipid metabolism in the body. | View Page |
| ApoB and ApoA1 By measuring ApoB we can quantify the amount of all atherogenic or potentially atherogenic lipoproteins that carry this apolipoprotein. Although lipoprotein particles other than LDL can carry ApoB, LDL accounts for the vast majority of ApoB; therefore, it is a good index of LDL particle number. Furthermore, the other particles that can have ApoB (such as IDL and Lp(a)) are also atherogenic and so it is not problematic if they are counted along with LDL, since they also contribute to cardiovascular risk. What about ApoA1? HDL-C is known as 'good cholesterol'. The role for HDL in the body is to sequester excess cholesterol and bring it back to the liver. Since HDL can remove cholesterol and transport it back to the liver for excretion or re-utilization it is indeed good. HDL is a negative cardiovascular risk factor; as its concentration goes up, a person's cardiovascular risk decreases. A person with low cardiovascular risk would have low ApoB levels and high ApoA1 levels. If we measure both ApoB and ApoA1 and express them as a ratio of ApoB/ApoA1 we get a powerful cardiovascular risk marker. The ratio should be approximately 0.3-0.9. Patients with a higher ratio have elevated ApoB (LDL) and/or low ApoA1 (HDL) and are thus at increased risk. By combining these two markers in a ratio, we get synergy and enhanced predictive power. | View Page |
| More on Howell-Jolly Bodies Under normal conditions, Howell-Jolly bodies are thought to be remnants of nuclear fragments due to incomplete expulsion of the nucleus. In pathological conditions, they are aggregates of chromosomes which have separated from the mitotic spindle during abnormal mitosis. Single or multiple Howell-Jolly bodies may be found in a red cell. A single HJ body in a red cell may be seen in megaloblastic anemia, hemolytic anemia such as sickle cell anemia and after splenectomy. Megaloblastic anemia or abnormal erythropoiesis is usually present when multiple Howell-Jolly bodies are observed in a single cell. | View Page |
| The inclusion seen in the red cell just above center in this field is a ___________ body. | View Page |
| Comparison of Erythrocyte Inclusions In section A of the image, the arrow points to an RBC with basophilic stippling.In section B, the arrows point to erythrocytes containing Pappenheimer bodies.The arrows are pointing to Howell-Jolly bodies in section C.By contrast, in section D the arrow is pointing to a platelet that is sitting on top of an RBC. This may be mistaken for an inclusion. One of the distinguishing characteristics that can alert you to the fact that it is not an inclusion is the halo around the platelet. | View Page |
| Howell-Jolly Bodies contrasted with Pappenheimer Bodies. Pappenheimer bodies are indicated with single arrows. A Howell Jolly body is shown at the double arrow. | View Page |
| An Introduction to the Fundamentals of Coagulation The ability of the body to maintain a state of homeostasis, or physiological equilibrium, is absolutely essential for effective, efficient functionality of all body systems.
The mechanisms involved in blood coagulation, also known as hemostasis or blood clotting, serve to illustrate this concept.
Hemostasis is the cessation of free blood flow, external to the vascular system, when a vessel wall has been breached.
With the maintenance of homeostasis in mind, it is vital that the body be able to rapidly repair vascular damage, arresting blood flow in the process, while simultaneously maintaining blood in a fluid state within the vascular compartment.
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| Introduction to Primary Hemostasis Primary hemostasis is considered the starting point for the hemostatic response mounted by the body, subsequent to vascular damage. Its activation serves as a trigger for ensuing hemostatic processes, as the mechanisms are all interrelated. Primary hemostasis consists of two key parts: The vascular system Platelets (thrombocytes) | View Page |
| Summary of Primary Hemostasis In summation, we have covered the following sequence of events which comprise primary hemostasis. The process begins with damage to a vessel wall, as blood flows outside the vasculature. The body responds with vasoconstriction, decreasing blood flow to the affected area. Platelets begin sticking to the damaged vessel walls. As the platelets stick, they release chemicals which signal other platelets to respond. As other platelets arrive, they begin sticking to one another, clumping together, forming a plug to fill in the breach. This plug, while strong, is a temporary fix, and must be reinforced with fibrin strands to effectively fill the breach during the vessel repair process. Construction of the fibrin strands occurs during secondary hemostasis, our next topic to be covered. | View Page |
| Coagulation Disorders - Acquired Disseminated Intravascular Coagulation (DIC) is best described as a disorder of consumption, because clotting factors are depleted from the blood. Basically, clotting occurs randomly throughout the body, as opposed to just in the localized areas where vascular damage has occurred, consuming clotting factors and other components such as platelets in the process. Symptoms may range from a mild bleed, to severe, profuse bleeding, primarily dependant upon the availability of clotting factors. As more and more coagulation factors and components are consumed, the disorder progresses and symptoms worsen. Most heavily impacted are the levels of factors I, V, and VIII as well as the number of available platelets. Clinically, DIC is detected via an elevated (positive) FDP, positive D-dimer test, a prolonged PT and APTT, plus the manifestation of hemorrhagic episodes. DIC is diagnosed as two primary types, acute and chronic. Acute DIC manifests in a few hours or a few days, has a high mortality rate, and is seen in infections, obstetric complications, liver disease, and tissue injury. Chronic DIC is a secondary condition to some other disease state. Once you treat the primary disease, this type of DIC will go away. Treatment is often factor replacement therapy through the use of fresh frozen plasma and/or cryoprecipitate. | View Page |
| Coagulation Disorders and Liver Disease The liver is the site of production for the vast majority of our clotting factors. Therefore, impaired liver function could adversely affect these hemostatic proteins. Some early indicators of a potential liver problem include: An increase in factor VIII. It is not produced in the liver and will be present in elevated numbers as the body attempts to compensate. The PT is sensitive to liver function, so an unexpected, prolonged PT should be evaluated. A lack of fibrinogen is often indicative of severe liver disease. It is difficult to treat liver disease, so therapy typically centers around replacing the missing factors by way of administration of fresh frozen plasma. | View Page |
| Targets Molecular based clinical diagnostic test methodologies differ according to the target of interest. For example, patients suspected of having different diseases will require the identification of different targets. These targets might be found in different cells of the body and may therefore require different specimens to provide the answers. Patient A suspected of having Disease 1-requires the identification of a target of missequenced DNA- might require specimen of whole blood Patient B suspected of having Disease 2-requires identification of a target of antibody production-methodology might require specimen of serum Using this specific approach of disease diagnosis based on unique target identification, tests can provide answers that are more rapid sensitive specific | View Page |
| Basis of Molecular Testing The basis of molecular testing lies in the genetic material of a cell. Both prokaryotic and eukaryotic cells possess nucleic acid. The two types of nucleic acid include deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). The foundational building blocks of both DNA and RNA include nucleotide bases of purines and pyrimidines. The unique sequencing of these nucleotide bases found in each strand of DNA or RNA contribute significantly to the language of cells. This cellular based language is responsible for many complex activities within the human body, including the synthesis of proteins. | View Page |
| Pharmacogenetics Adverse drug reactions are a leading cause of morbidity and mortality in the United States. Drug metabolism is a process whereby drugs are delivered to the body, distributed, metabolized and then ultimately excreted. As there can be potentially significant differences between patient drug absorption, metabolism and excretion, molecular testing allows a physician to work with a patient's individual phenotype and/or genotype to deliver an optimum pharmaceutical selection and/or dosage. | View Page |
| Overview Because hereditary hemochromatosis (HH) is a disease of iron overload, a review of the basic principles of iron metabolism is helpful in understanding its pathophysiology. Iron is needed by all body cells and is crucial for oxygen transport, oxidative metabolism, and cell growth and proliferation. To serve these functions, iron must be bound to protein. Iron is potentially harmful when ionized or complexed to inorganic compounds. Iron must be present in amounts sufficient to carry out these normal functions, but not in excessive amounts which may be toxic.Two types of iron-containing compounds are normally found in the body: compounds that serve in metabolic or enzymatic functions and storage compounds. Hemoglobin, myoglobin, cytochromes and other proteins are involved in oxygen transport and utilization. Iron in hemoglobin comprises about 67% of total body iron, thus erythrocytes are rich in iron. Approximately 27% of iron is found in storage compounds. Myoglobin, other tissue iron, and transport iron comprise the remaining 6% of total body iron. (2) | View Page |
| Which compound normally contains the majority of the body's total iron? | View Page |
| Storage Iron Storage forms normally comprise approximately 27% of total body iron. Stored iron provides a source of iron when physiologic demand is high, such as in blood loss, pregnancy, and periods of rapid growth. Storage compounds include ferritin and hemosiderin. Ferritin is a protein-bound, water-soluble, mobilizable storage compound and is the major source of stored iron. Hemosiderin is a water-insoluble form that is less readily available for use. When the amount of total body iron is relatively low, storage iron consists predominately of ferritin. When iron stores are increased, hemosiderin predominates. Unlike ferritin, hemosiderin stains with the Prussian blue stain (Perls reaction) and may be observed in tissues. | View Page |
| Iron Intake and Recycling The typical daily diet of most Americans contains approximately 10 to 15 mg of iron. Sources of dietary iron include heme iron from meats and nonheme iron from whole grains and vegetables. Many processed foods, such as breakfast cereal, are fortified with iron. However, the normal individual absorbs only 5% to 15% of dietary iron, or about 1 to 2 mg daily. Females may absorb slightly more iron than males as they require more iron to replace that lost through menstruation and to meet the increased need for iron in pregnancy.Absorption of iron occurs through the mucosal cells in the duodenum (proximal small intestine). Dietary iron that is not absorbed is excreted in the feces. Intestinal absorption provides the means for regulating the amount of iron in the body.The amount of Iron absorbed is normally low because iron is well conserved within the body. Heme iron from senescent erythrocytes is cycled back into the iron pool and reused for incorporation into developing erythrocytes. Furthermore, iron is normally lost from the body only in very small amounts, primarily through desquamation of mucosal cells in the gastrointestinal tract and losses through body secretions, including urine, sweat and feces. Therefore, under normal conditions, very little dietary iron needs to be absorbed to maintain iron homeostasis.(3) | View Page |
| Serum Iron Serum iron (SI) is a measure of circulating iron bound to transferrin and is reflective of total body iron. SI is elevated in hereditary hemochromatosis (HH) and acute hepatitis. SI is decreased in iron deficiency anemia and chronic inflammation. SI concentrations exhibit diurnal variation, with the lowest values occurring around midnight. In addition, specimens collected from the same individual at the same time of the day may exhibit day to day variations as high as 40%. SI determinations are also affected by diet, menstrual cycle, pregnancy, ingestion of iron supplements, and oral contraceptive use. SI levels alone are considered insensitive indicators of HH. SI is typically measured on automated analyzers using spectrophotometric methods. Iron in the sample is released from transferrin with an acid reagent, reduced to the ferrous state, and reacted with a chromogen such as bathophenanthroline or ferrozine. The intensity of the color change is proportional to the iron concentration. Interference can arise from the use of a hemolyzed sample and contamination of reagents and water with iron. A typical reference interval for SI is 60 - 150 micrograms/dL. SI is usually ordered along with its companion test, the total iron binding capacity (TIBC), or with transferrin (Tf).(2) | View Page |
| HIV is known as a retrovirus because: | View Page |
| Which of the following is not considered a potentially infectious body fluid for transmitting HIV? | View Page |
| Mutations Genetic mutations in HIV are well known and are very likely, considering the presence of two RNA molecules per virus. Either or both RNA molecules can mutate. These mutations potentially lead to drug resistance or encourage the virus to evade the body's immune response. Mutations have created three major groups of HIV - M, N, and O. M is found in 99% of all the HIV cases in the world. N and O are primarily found in West African countries. N, though, infects only a very small number of individuals. The M group has subgroups lettered A to J. Subgroup B predominates in North America. | View Page |
| Introduction Acquired Immunodeficiency syndrome (AIDS) is caused by the Human Immunodeficiency virus (HIV). When HIV enters a person's bloodstream, it attacks and kills the T-helper lymphocytes, which are essential to the body in fighting off infections. As these cells are lost, so is the body's ability to fight infection. Possibly months after the initial infecting episode, an infected person develops a mononucleosis-like illness lasting a week or two. A person may then be free of symptoms for years. But as the T-helper cells die, the person becomes vulnerable to many serious infections. The expected mortality is 100%, and there is no vaccine available to develop specific immunity. | View Page |
| Occupational Exposures HIV transmission, due to occupational exposure, occurs by: Percutaneous injury, such as a needlestick or a cut with a sharp object; Contact of mucous membrane or abraded skin with HIV-infected blood or body fluids. The risk of HIV transmission after a percutaneous exposure to HIV-infected blood is 0.3%.The risk of HIV transmission after a mucous membrane exposure to HIV-infected blood is .09%.The risk of HIV transmission after contact of abraded skin with HIV-infected blood is estimated to be less than .09%. | View Page |
| Potentially infectious body fluids These substances are considered potentially infectious for an occupational exposure: blood cerebrospinal fluid synovial fluid pleural fluid peritoneal fluid pericardial fluid amniotic fluid any body fluid visibly contaminated with blood semen or vaginal fluid tissues removed during surgery. | View Page |
| Which of the following does not pose a significant risk for transmitting HIV? | View Page |
| Overview Prevention of HIV exposure is the best line of defense to prevent occupational transmission of HIV as there is no vaccine available to develop specific immunity and the postexposure prophylaxis is toxic. Following appropriate workplace practices in the laboratory focus on preventing needlesticks or other sharps injuries and exposure of mucous membranes and abraded skin to HIV-infected blood or body fluids. | View Page |
| Gloves Gloves must be worn: when there is a reasonable chance of exposure to blood, other infectious body fluids, mucous membranes, or nonintact skin. during vascular access procedures, including phlebotomy. when handling contaminated items or surfaces.Wear only flat rings under gloves as large rings may tear gloves.Replace gloves: Between patient contacts If they are damaged or contaminated Before leaving the work area. Wash hands after removing gloves.Never wash disposable gloves. | View Page |
| HIV is known as a retrovirus because: | View Page |
| Mutations Genetic mutations in HIV are well known and are very likely, considering the presence of two RNA molecules per virus. Either or both RNA molecules can mutate. These mutations potentially lead to drug resistance or encourage the virus to evade the body's immune response. Mutations have created three major groups of HIV - M, N, and O. M is found in 99% of all the HIV cases in the world. N and O are primarily found in West African countries. N, though, infects only a very small number of individuals. The M group has subgroups lettered A to J. Subgroup B predominates in North America.
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| Infection of the Host Cell (2) The DNA provirus continues to encode new HIV particles within the host cell. During this early stage the injured host cells, such as T-lymphocytes, are able to replace themselves, and the body remains able to launch a defensive response. Eventually, though, the number of viruses becomes overwhelming. | View Page |
| Agent: Viral hemorrhagic fevers (Ebola, Marburg, Lassa and Argentine) Most likely means of dissemination: Solid, liquid or aerosolPrimary route of entry: Absorption, inhalation, ingestionGeneral signs and symptoms: Vary by type of viral hemorrhagic fever (VHF), but initial signs and symptoms often include marked fever, fatigue, dizziness, muscle aches, loss of strength, and exhaustion. Severe cases of VHF often show signs of bleeding under the skin, in internal organs, or from body orifices like the mouth, eyes, or ears. Photo courtesy of the CDC archives. | View Page |
| In Case of a Dirty Bomb Attack Stay inside or get inside quickly. Find a “Shelter-in-place”. To “shelter in” is a way to make the building you are in safe as possible to protect yourself until help arrives. You should not try to “shelter in” in a vehicle unless you have no other choice. The best room to use is one with as few windows and doors as possible. Be sure to close all windows and doors, and turn off the furnace, air conditioners, and exhaust systems. As best as possible, seal all openings in windows and doors. Monitor your radio for instructions from authorities. If you believe you’ve been exposed and you can’t get to a hospital, shed all your clothes as quickly as possible. Don’t take the clothes inside because you may spread contamination. Go straight to the shower and thoroughly wash all body parts with a coarse soap. It is important not to ingest radiation by eating contaminated food or even chewing on contaminated fingernails. Also, certain types of radioactivity can be flushed from the body by drinking large amounts of water. After an attack don’t travel through heavily contaminated areas. If you can get out of the general area through an uncontaminated route, do so—otherwise, stay indoors until assistance arrives. | View Page |
| Scenario #1 Pam is seated at the workbench where she routinely prepares dilutions using an automated pipette. She leans to the right and stretches over her rack of tubes each time she needs to change a pipette tip. Pam is working in an awkward body position because the pipettes are not in a convenient location and the space is not well organized.By changing the location of the pipettes to within her routine work area, she can avoid overstretching to reach the pipettes and avoid contorting her body into an awkward position that could eventually result in an MSD. As shown in the image, regularly used items should be close to the worker to avoid leaning forward and over-extending reach radius. Adjust your work space so that you can reach tools and equipment without unusual bending or twisting; arrange the work area properly within the "work zone".Avoid reaching more than 10 inches (25 cm) in front of the body for frequently used materials or 20 inches (50 cm) for items that are used occasionally. | View Page |
| Ergonomic Guidelines for Computer Users A. Computer monitors should be approximately 18" - 24" away from the eyes. The top of the monitor is best set at eye level so that the eyes gravitate toward the center of the screen. B. Try to avoid glare from the light. C. Computer monitors should be set directly in front of the user D. Keep forearms 90° from your spine and keep elbows in close to the body. E. If seated, thighs should be parallel to the floor and about a 90° angle with the calves. F. Use an adjustable chair, preferably with padded arms. Adjust the chair or work surface (if possible) to the correct position. Avoid leaning forward or to the side. Do not lean on work surfaces. Do not lean on elbows or armrests. Keep neck and shoulders in a relaxed position.G. Place keyboard in a comfortable position (preferably on an adjustable keyboard tray) and use a wrist/palm rest. H. Place feet flat on the floor or on a footrest and do not crowd the legs or body into a cramped or cluttered work space. Use a document holder to keep working documents at eye level with the screen. To avoid eyestrain, follow the 20/20/20 rule. Every 20 minutes, take a 20 second break to focus on a spot 20 feet away. | View Page |
| Body Position Take frequent posture breaks; if standing, sit periodically. If sitting, stand about every 20 minutes and walk around. Shoulders and Arms Keep the shoulders relaxed, not shrugged-up or slumped-down. Keep your elbows close to your body Keep work at elbow height and directly in front of you as shown in the image below. Head and Neck Avoid situations that require prolonged or repetitive twisting, forward-bending, or backward-bending of the neck.Hands and Wrists Keep the hand in line with the forearm. Avoid repetitive twisting of the wrists. Avoid working with wrists pressed against hard surfaces or edges as shown in the image below. Feet and Legs Place a foot on a footrest for comfort Provide a toe space to allow work closer to counters and reduce reaching. Use mats on hard floors to reduce fatigue as shown in the image below.Back Stand straight. Avoid situations that require bending forward, backward, leaning side-to-side, or twisting. Use a stool to provide an occasional change in posture. If working seated, use a back rest/support to maintain proper posture. The chair that is shown in the image below offers neck, back, and lumbar support. | View Page |
| Guidelines for Lifting, Lowering and Carrying Reduce the weight of an object whenever possible by reducing the container size/capacity. Reduce the hand distance from the body by changing the shape of the container or providing grips or handles enabling the load to be held closer to the body. Use carts, hand trucks, etc. to convert load lifting to a push or pull task. Reduce the carrying distance by moving the storage area closer to production areas. Assess an item before lifting it. Get help if the item is too heavy, large, or awkward. Store heavy objects on shelves below shoulder height and no lower than knee-height. Store materials that are frequently used on shelving units that are located no higher than shoulder height. Lifting a heavy objectTo pick up the item, secure it firmly in your hands, keep the item close to the body, bend your knees, keeping your back in its natural arched position, and lift with your legs; leg muscles have more power than the smaller muscles in the back. The object to be lifted should be directly in front of you. Lift it straight up, using a smooth motion. Avoid asymmetric lifting (twisting while lifting). | View Page |
| Work Station Evaluate your work station including leg room, reach radius, accessibility of commonly used materials, and height of the work surface. Adequate space should be available to accomodate equipment and allow for full range of motion. ChairPersonnel who sit for long periods of time should adjust chairs so that feet are flat on the floor or on a footrest. Chairs should have some primary features that can be easily adjusted including controls to raise and lower chair, seat pan adjustment, lumbar support, and backrest tilt or angle. Adjust the seatback slightly forward if necessary to avoid leaning forward unsupported or jutting your head forward. Reach radius Regularly used items should be close to the worker to avoid leaning forward and over-extending reach radius. Adjust your work space so that you can reach tools and equipment without unusual bending or twisting.Avoid reaching or bending - arrange the work area properly within the "work zone". Avoid reaching more than 10 - 15 inches in front of the body for frequently used materials or 20 inches for items that are used occasionally.Avoid reaching above shoulder height, below waist level, or behind the body to minimize shoulder strain.Avoid repetitive work that requires full arm extension (i.e., the elbow held straight and the arm extended).The image illustrates a workstation that is used by a technologist who performs microscopic work for the majority of the workday. The workstation is designed to prevent musculoskeletal disorders and fatigue. | View Page |
| What is the recommended reach radius for items that are used routinely at your work station? | View Page |
| Description of Specialties (1) Specialists in microbiology perform testing to diagnose and stop the spread of infectious organisms, including bacteria, viruses, and parasites. Specialists should be able to isolate and identify a wide variety of these organisms. Testing procedures include direction examination and antigen detection methods.
Specialists in serology and immunology measure antibodies to infectious organisms. Specialists should be familiar with all serology techniques (except those specific to immunohematology). This specialty includes all lab procedures performed in the specialty of histocompatibility.
Specialists in hematology must be able to identify and evaluate cells in blood and bone marrow and identify disorders of these cell. Specialists should be familiar with routine and special tests to determine the number, morphology, and function of cells in body fluid. | View Page |
| Description of Specialties (2) Specialists in immunohematology perform all testing prior to blood transfusions and work to prevent transfusion infections. They also investigate any post-transfusion reactions. This specialty includes all lab procedures performed in the specialty of histocompatibility. Specialists in clinical chemistry analyze body fluids such as blood, urine, and spinal fluid to determine the chemical makeup, including the amount of carbohydrates, proteins, enzymes, and trace elements. The special covers urine microscopics and chemical evaluation of the liver, kidneys, lungs, heart, and other vital organ systems. This specialty also covers all testing performed in the specialties of radioassay and blood gas analysis. Specialists in blood banking can perform all immunohematology testing as well as testing from the specialties of clinical chemistry, hematology and serology/immunology that relates to donor blood. Clinical laboratory personnel who are licensed in the specialties of immunohematology, clinical chemistry, hematology, and serology / immunology may perform all tests in the blood banking specialty. | View Page |
| Description of Specialties (3) Specialists in radioassay use radionuclides to determine the chemical makeup of body fluids such as blood and urine.
Specialists in blood gas analysis evaluate lung and breathing function by levels of oxygen, carbon dioxide, pH, and hemoglobin with automated tests.
Specialists in histology examine cellular and tissue samples using fixation, dehydration, embedding, microtomy, frozen sectioning, staining, and other similar techniques. Histology specialists licensed as technicians can perform specimen processing, embedding, cutting, staining, and frozen sectioning only under the general supervision of a director, supervisor, or technologist.
Specialists in cytology process and interpret samples relating cytopathological disease. Non-gynecological cytology preparations can be screen by a specialist in cytology but final review and interpretation must be done by a physician. | View Page |
| Where is the main site of action for monocytes? | View Page |
| What is the Function of Lymphocytes? Lymphocytes are primarily involved in the body's immune response mechanism. This involves complex phenomena which end in the development of humoral and cellular immunity. | View Page |
| Monocytes Monocytes are phagocytes which remove injured and dead cells, cell fragments, microorganisms and insoluble particles from the blood and body tissues.Monocytes also secrete substances that affect the function of other cells, especially lymphocytes.They are produced in the bone marrow, and when mature are released into the peripheral blood. Although they do serve a phagocytic role in the blood, their main site of action is the body tissues.The half-life for monocytes in the peripheral blood is approximately 8 hours. Monocytes migrate into the tissues, often to sites of inflammation, where they serve their primary purpose.Here they transform into fixed or free macrophages, and continue their function as avid phagocytes.When activated, macrophages may enlarge and have enhanced metabolism.
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| Function and Kinetics Erythrocytes are produced in the bone marrow and released into the peripheral blood where they may remain for approximately 120 days before senescence.Their main function is the transport of the respiratory gases (oxygen and carbon dioxide) between the lungs and body tissues.Each erythrocyte can be thought of as an "envelope" containing hemoglobin.Each hemoglobin molecule contains iron which has a high affinity for oxygen.As a result, when an erythrocyte passes through one of the capillaries of the lungs, it picks up oxygen.The oxygen is transported through the blood to the tissues where it is released.Carbon dioxide from the tissues then diffuses into the RBC where it undergoes chemical changes.About 70% of the altered carbon dioxide diffuses into the plasma, 25% binds to the hemoglobin molecule, and 5% goes into simple solution within the red cell.In each of these three ways carbon dioxide is transported from the body tissues back to the lungs, where it is released.
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| Erythrocytes or Red Blood Cells (RBC's) The first group is composed of erythrocytes or red blood cells (RBC's). The main function of the erythrocytes is the transport of oxygen from the lungs to the body tissues. Most of the cells in this Wright's stained peripheral blood smear are red cells. On is shown at the arrowhead. | View Page |
| Leukocytes or White Blood Cells (WBC's) The second group of cells are the leukocytes or white blood cells (WBC's). The leukocytes can be divided into two groups: mononuclear and granulocytic cells. Leukocytes are involved in various ways with the body's defense mechanisms. The cell shown in the upper image is a mononuclear cell, in this case a monocyte. The cell shown in the lower image is a granulocyte, in this case a neutrophil. These cells will be presented in much more detail later. | View Page |
| Glossary of Terms A through M. Antibody - A modified type of serum globulin synthesized by lymphoid tissue in response to antigenic stimulus. By virtue of specific combining sites each antibody reacts with only one antigen. Anucleate - Having no nucleus. Azurophilic granules - The well-defined large reddish granules (lysosomes) which may be present in large lymphocytes. They are called "azurophilic granules" because they stain blue with the azure stains which were originally used. Basophilic granules - Specific granules present in the cytoplasm of basophils. These granules are large and stain purple-black due to their strong affinity for basic stain. B-cell - Bone marrow derived lymphocytes which produce humoral antibodies. Biconcave - Having two concave surfaces. Cellular Immunity - The capacity of a small proportion of lymphoid population to exhibit response to a specific antigen. Chromomere - The centrally located granular portion of the platelet. Clone - A population of cells descended from a single cell. Delayed Hypersensitivity - (part of cellular immunity) that develops slowly over a period of 24-72 hours after an antigenic stimulus. It consists of an accumulation of cells around small vessels and/or nerves. Example: Tuberculin skin test reaction. Digestive Enzyme - A substance that catalyzes or accelerates the process of digestion. Eosinophilic Granules - Specific granules present in the cytoplasm of eosinophils. These granules are large, refractile spheres which stain reddish-orange due to their strong affinity for acid stain. Erythrocyte (red blood cell, RBC) - One of the elements found in peripheral blood. Normally the mature form is a non-nucleated, circular, biconcave disk adapted to transport respiratory gases. Fixed Macrophage - A phagocyte that is non-motile. Free Macrophage - An ameboid phagocyte present at the site of inflammation. Graft Rejection - A transplanted tissue that is rejected by the body's antibodies. Graft vs. Host Reaction - A complication that occurs when an implanted piece of tissue, which contains antibodies, rejects the host's tissue. Granulocyte - A leukocyte which contains granules in its cytoplasm, i.e., neutrophilic, eosinophilic, or basophilic granules. Half-life - is the length of time it takes for half of the cells circulating at a given time to leave the blood for the tissues. Hemocyte - Any blood cell or formed element of the blood. Hemostasis - A mechanism of the vascular system to arrest an escape of blood. It involves an interaction between blood vessels, platelets, and coagulation. Heparin - A mucopolysaccharide acid which, when present in sufficient amounts, functions as an anticoagulant by inhibiting thrombin. Histamine - A powerful dilator of capillaries and a stimulator of gastric secretions. Humoral Immunity - Acquired immunity produced after response to an antigenic stimulus in which B cells produce circulating antibodies. Hyalomere - the clear, blue non-granular zone surrounding the chromomere of a platelet. Immune Response - The interaction of a cell and an antigen that results in a proliferation of the cell and a capacity to produce antibodies. Isotonic Fluid - A fluid whose elements have an equal osmotic pressure. Leukocyte (white blood cell, WBC) - One of the formed elements of the blood; involved primarily with the body's defense. Lysosome - A microscopic body within cell cytoplasm; contains various enzymes, mainly hydrolytic, which are released upon injury to the cell. Megakaryocyte - A giant cell of the bone marrow from which platelets are derived. Mononuclear - A cell having a single nucleus. | View Page |
| Glossary of Terms N through Z. N:C Ratio - Nuclear: cytoplasmic Ratio - The ratio of nuclear volume to cytoplasmic volume within any one cell.Neoplasm - Any new and abnormal growth, such as a tumor.Neutrophilic Granules - Specific granules present in the cytoplasm of neutrophils. These granules resemble pencil stippling and stain a lilac color due to their affinity for both basic and acid dyes.Phagocyte - Any cell that ingests microorganisms or other cells and foreign particles.Phagocytosis - The ingestion and destruction of microorganisms or other foreign particles.Plasma - The fluid portion of blood in which the various blood cells are suspended.PF3 (platelet Factor 3) - A lipoprotein component of the platelet membrane; functions as a surface catalyst during blood coagulation.Pseudopod - A temporary protrusion of the cytoplasm of a cell.Refractile - Capable of refracting or changing the direction of light.Senescence - The process or condition of growing old.Serotonin - A constituent of blood platelets and other cells and organs; induces constriction of the blood vessels.Specific Granules - Granules found in cells of the more mature stages of the granulocytic series. They have distinct staining reactions which differ with each type of granulocyte.T-cell - Thymus derived lymphocyte which mediates cellular immunity.Thrombocyte (Platelet) - A circular or oval disk found in the blood; concerned with hemostasis.Thymus - A ductless gland-like body situated in the anterior mediastinal cavity; reaches its maximum development during the early years of childhood.Vacuole - Any small space or cavity formed in the cytotoplasm of a cell. | View Page |
| The Process of Phagocytosis Neutrophils have a relatively short life span.They are produced in the bone marrow, and when they reach the band or segmented stages are released into the peripheral blood.They remain there for approximately ten hours before randomly entering body tissues.Neutrophils in the blood stream can be divided into circulating granulocyte pool(CGP) and marginating granulocytic pool (MGP).The white blood cell count reflects the cells in the circulating pool.The cells in the marginating pool move quickly into the circulating pool when needed.During an infection the neutrophil concentration of the peripheral blood can increase almost immediately due to the shift of these cells from the marginating pool and release from the bone marrow storage pool, if needed.Neutrophils then migrate to areas of tissue damage or infection.Neutrophils do not reenter the blood stream from the tissues, thus end their life in the tissues either as a result of phagocytosis or senescence. | View Page |
| Mast Cells Mast cells are similar in appearance to basophils, are a separate cell line and are life-long residents of connective tissue throughout the body. They have some functions similar to those of basophils.
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| Where do neutrophils serve their primary function? | View Page |
| You Are At Risk! As a healthcare worker, you come into contact with materials that may contain bloodborne pathogens. These are infectious organisms, usually viruses, which live in human blood and body fluids.The most important ones are: Hepatitis B Virus (HBV) Human Immunodeficiency Virus (HIV) Hepatitis C Virus (HCV) | View Page |
| About This Course This course will provide you with basic information about bloodborne pathogens, the regulations that govern safe work practices when handling blood and other potentially infectious body fluids, and necessary precautions that must be taken to minimize your risk of exposure to these infections. | View Page |
| Exposure category There are three exposure categories :Category I are those employees who on a day-to-day basis will come in contact with blood or body fluids as part of their normal job. This includes medical technologists, pathologists and operating room nurses.Category II are those employees who may come in contact with blood or body fluid during the course of their normal job. This includes housekeepers, transporters, and some technicians such as EKG techs.Category III are those persons who would not normally ever come in contact with blood or body fluids and generally includes secretaries, administrators and gardeners.Persons may move from one category to another during the course of a work-day. | View Page |
| Standard Precautions! Standard precautions mean that all blood and body fluids should be handled as if they were infectious and capable of transmitting disease. Standard Precautions apply to all: Blood Body fluids Secretions (except sweat) Excretions Non-intact skin Mucous membranes | View Page |
| How can HBV be prevented? You can avoid exposure to Hepatitis B by taking the appropriate precautions, such as: Receiving the immunization against Hepatitis B. Following standard precautions. Maintain proper work practices. Using proper techniques when handling materials which may be contaminated with blood or other potentially infected body fluids. | View Page |
| How is HBV Spread? The virus is spread when body fluids from an individual with the Hepatitis B virus are introduced into the body of a susceptible person.This contact may occur during introduction of blood or potentially infectious body fluid: Through an opening or sore in the skin. Via a puncture with a contaminated sharp such as a needle. Through direct contact with mucous membranes that line the insides of the mouth, nose, eyes, and the genital organs. HBV is not spread through casual contact, such as handshake, or through sweat. | View Page |
| Who is infected? Patients with Hepatitis B and other bloodborne infections can appear healthy, so you can't tell whose blood is infectious.So treat all: blood body fluids secretions (except sweat) excretions non-intact skin mucous membranes as if they were infectious.That's what the term Standard Precautions means. | View Page |
| Body Fluids Most Likely To Transmit HBV Body fluids most likely to transmit HBV are: Blood Semen Vaginal Secretions Pleural Fluid Peritoneal Fluid Pericardial Fluid Cerebrospinal Fluid Synovial Fluid Amniotic Fluid Blood contaminated saliva in dental procedures Any fluid visibly contaminated with blood Sweat uncontaminated by blood is not considered infectious. | View Page |
| Spread of HBV In The Community HBV is spread in the community through: Sexual contact. Drug abusers sharing contaminated needles. An infant's exposure to its mother's body fluids. | View Page |
| What causes HIV Infection? HIV infection is caused by the human immunodeficiency virus.The infection occurs when HIV enters a person's bloodstream, where it attacks and kills the helper T-cells. Helper T-cells are part of a group of white blood cells, known as lymphocytes, which are essential to the body in fighting off infections.As the numbers of these cells decreases, so is the body's ability to fight infection. | View Page |
| Transmission of Hepatitis B can be prevented by: | View Page |
| Transmission of the hepatitis B virus (HBV) can occur from all of the following EXCEPT: | View Page |
| Contaminated Wastes It is important to always dispose of contaminated wastes properly!Examples of contaminated wastes: Microbiology waste and pathology waste All body fluids, such as pleural fluid Contaminated sharps and blood specimens | View Page |
| Gloves Gloves made of either latex or a latex equivalent material such as nitrile must be worn whenever there is a risk of contact with blood or other body fluids.Keep hand jewelry worn under gloves to a minimum to protect their integrity.Replace gloves: Between patient contacts If they are damaged or contaminated Before leaving the work area. Perform hand hygiene after removing gloves. Disposable gloves cannot be washed.Utility gloves or heavy-duty rubber gloves are useful when cleaning up spills or when there is a risk of damage from equipment handling.Utility gloves may be decontaminated and reused if their integrity has not been compromised. They should be inspected regularly, and must be replaced if damaged. | View Page |
| Gloves Must be Worn When there is a reasonable chance of exposure to blood, other infectious body fluids, mucous membranes, or nonintact skin. During vascular access procedures, including phlebotomy. When handling contaminated items or surfaces. | View Page |
| Exposure Incident Even after taking all the proper precautions there is still a small chance of an exposure incident. An Exposure incident occurs when: Blood or another potentially infectious body fluid comes into direct contact with mucous membranes or non-intact skin. Parenteral exposure means: Exposure occurring as a result of piercing the skin barrier through needlesticks, cuts, or abrasions. | View Page |
| Which of the following can lower the amount of current needed to cause electricity-induced injury? | View Page |
| If a person comes in direct contact with an electrical source and sustains an electrical shock, which of the following actions should be taken once the current has been shut off and/or the person has been freed from contact with the current? | View Page |
| Factors that Determine the Degree of Electricity-induced Injury The degree of electricity-induced injury is dependent on: The amount of electrical energy that is delivered The resistance that is encountered The type of current The current pathway The duration of contact | View Page |
| Unplugging an Electrical Cord Electrical cords should be unplugged by holding the cap and not by pulling on the cord. Hands should not be wet when plugging or unplugging electrical cords. Moisture will reduce the contact resistance of the body, and electrical insulation is more subject to failure. Unplug all equipment during servicing. | View Page |
| Ground A ground is a conducting connection between an electrical circuit or equipment and the earth, or between an electrical circuit and some conducting body that serves in place of the earth.The purpose of a ground is to prevent the buildup of voltages that may result in a hazardous situation for the connected equipment and/or for the person operating the equipment.All electrical equipment in the laboratory that is not clearly marked as "double-insulated" must be grounded by using a three-pronged power cord. | View Page |
| Electrical Shock Direct contact with electrical current can cause sustained muscular contraction that may prevent the victim from releasing the electrical source. Shut off the electrical current if it can be done safely by unplugging the cord or turning off the main power switch. Merely turning off an instrument or appliance will not always stop the flow of electricity.If the current cannot be turned off, a non-conductive material such as a broom, chair, rug, or rubber mat can be used to push the victim away from the source of the current. Don't use a wet or metal object, and do not touch the victim with your bare hands. Verify that the object that is used does not have a metal core. As an extra precaution, stand on something dry and non-conducting such as a mat or stack of paper while attempting to free the victim from the electrical current. Call a physician immediately. Lower the victim's head to slightly lower than the trunk of the body, and elevate the legs. Cover the victim with a blanket or coat. Begin CPR if the victim's breathing and/or pulse has stopped or seems dangerously slow or shallow. | View Page |
| Exempt Substances Laboratory specimens that are unlikely to cause disease and do not meet the criteria for category A or B substances are not subject to Division 6.2 regulations. Specimens for which the hazardous materials regulation (HMR) does not apply include human or animal samples (including, but not limited to, secreta, excreta, blood and its components, tissue and tissue fluids, and body parts) being transported for routine testing not related to the diagnosis of an infectious disease. This includes specimens that are being sent for: drug or alcohol testing cholesterol testing blood glucose level testing prostate specific antibody (PSA) testing testing to monitor kidney or liver function pregnancy testing tests for diagnosis of non-infectious diseases such as cancer biopsies | View Page |
| Definitions Before further discussion of Category A and Category B, it is important to define two additional terms that are used in the classification process. CultureAn infectious substance containing a pathogen that is intentionally propagated, for example a bacterium grown on bacteriological medium as seen in the image below. Culture does not include a human or animal patient specimen.Patient specimenHuman or animal materials collected directly from humans or animals and transported for research, diagnosis, investigational acitivities, or disease treatment or prevention. Patient specimen includes excreta, secreta, blood and its components, tissue and tissue swabs, body parts, and specimens in transport media (e.g., transwabs, culture media, and blood culture bottles).* *It is important to note that this means specimens that have been collected into these transport media, but have not yet been incubated and are not actively growing in the media. | View Page |
| Match each parasite listed here with its corresponding infective stage: | View Page |
| Arrange the following parasites in order according to life cycles from simple to most complex: | View Page |
| Arrange the following phases of the hookworm life cycle in order beginning with human contact: | View Page |
| Which of the parasites listed here is/are transmitted via ingestion of contaminated pork? | View Page |
| Which of the following parasites may be contracted by swimming in contaminated water? | View Page |
| Arrange the following life cycle phases of Diphyllobothrium latum in order beginning with human transmission: | View Page |
| Arrange the following phases of the Wuchereria bancrofti life cycle in order beginning with human transmission: | View Page |
| The adult worms of which of the following parasites reside in human intestine? | View Page |
| Which of the following parasites have/has a life cycle that resembles that of the Plasmodium species? | View Page |
| Arrange the general schistosome life cycle phases in order beginning with that found in the human: | View Page |
| This suspicious form was recovered in muscle tissue. | View Page |
| Which parasite listed here is capable of crossing the placenta and causing serious harm to fetus? | View Page |
| A 32 year old male was seen in the emergency room with gastrointestinal discomfort. Upon questioning the patient it was learned that he first began feeling ill after spending a day at the park where he swam and played volleyball barefooted. He first noticed a lesion on his foot. Later, he developed vague respiratory symptoms. Now his largest complaint is severe abdominal pain along with occasional vomiting. This patient is most likely suffering from: | View Page |
| This stool parasite measures 55 µm by 50 µm and is the causative agent of: | View Page |
| Perianal itching is the major symptom of infection with both forms of the organism pictured here. This parasite is the causative agent of: | View Page |
| Arrange the following hookworm symptoms in order of their occurance based on the parasite's migration through the body beginning with human transmission: | View Page |
| Match each parasite name listed below with its corresponding picture: | View Page |
| Match each parasite listed here with its respective common name: | View Page |
| The body of a cestode is known as its: | View Page |
| Adult cestodes utilize this body part to attach to the human intestine: | View Page |
| The body of an adult cestode consists of segments called: | View Page |
| Match each pair of parasites listed here with the key morphologic characteristics that help to distinguish between them: | View Page |
| Match each parasite listed here with the key characteristic that aids in its identification: | View Page |
| Arrange the parasites listed here in increasing order (starting with none) based on the length of their undulating membranes: | View Page |
| Arrange the following morphologic forms based on complexity beginning with the simplest form: | View Page |
| Label the morphologic structures on this parasite form: | View Page |
| A 58 year old male, who recently returned from an extensive overseas business trip to Africa, presented to the local clinic complaining of nausea, vomiting, and an achy feeling all over his body. At first he thought it was just the flu, but it persisted. The doctor ordered a battery of tests including blood smears for parasitic study. This suspicious form was recovered. The patient is most likely suffering from: | View Page |
| A 16 year old male champion athlete went to his doctor complaining of a persistent cough, fever, bloody diarrhea and overall weakness. Upon questioning the patient, it was learned that he had recently competed in a freshwater swimming competition in the Caribbean. Examination revealed a dermatitis on the patient's right calf. A battery of tests were ordered including a CBC, chemistry profile, and a stool for culture and parasitic examination. The CBC revealed the presence of eosinophilia. The other hematology and chemistry tests were unremarkable. The culture was negative. This suspicious form was seen on all parasite preparations made from the stool sample submitted. This form measures 165 µm by 68 µm. This patient is most likely suffering from an infection with: | View Page |
| I am a mouth scavenger and measure about 10 µm. | View Page |
| I have been known to reside in a number of human tissue sites including the liver and lung. | View Page |
| I may be found in blood or in lymph nodes. | View Page |
| A parasite that takes up residence inside the human body host is called a/an: | View Page |
| Match the arthropod common name with its corresponding scientific name: | View Page |
| Basic Pharmacokinetics In order to discuss TDM and PGx we need to also introduce the concept of pharmacokinetics. Pharmacokinetics is the study of drug disposition in the body: how and when drugs enter the circulation, how long they remain in the blood, and how they are eliminated. TDM is the clinical assessment of a drug's pharmacokinetic properties. Physicians and pharmacists need to establish that a drug is present at an effective concentration but not at a toxic concentration. The next few pages will describe some of the factors that determine a drug's disposition in the body. These factors ultimately decide the need for therapeutic drug monitoring. | View Page |
| Protein Binding Most drugs are bound to proteins when they circulate in the body. Albumin is a major drug-binding protein in serum. Albumin is an alkaline protein, so acidic and neutral drugs primarily bind to it. If albumin binding sites become saturated, acidic and neutral drugs can bind to lipoproteins. Alkaline drugs tend to bind to globulins, particularly to the globulin, alpha-1 acid glycoprotein. Only free, unbound drugs are able to bind drug receptors and have therapeutic effects. An equilibrium exists in the systemic circulation between a free and protein-bound drug and between a free and receptor-bound drug. This is illustrated in the image to the right. | View Page |
| Other Factors Affecting Drug Absorption and Distribution In addition to protein availability, other factors may affect drug absorption and distribution in the body as a whole or at specific sites within the body. The following table highlights some of these other factors. Factor Discussion Regional blood flow Reduced area blood flow can be seen in diabetics and enhanced blood flow can be seen in tumors. Lipid solubility of the drug The more lipophilic a drug is, the more likely it will enter the central nervous system. The integrity of the GI tract In a diseased gut, an orally-administered drug may not be absorbed as expected. Age Drug kinetics and dispositions change throughout life. In general, metabolism of drugs is reduced in the elderly. Genetics Mutations or deletions in drug metabolizing enzymes can greatly affect a drug's disposition. | View Page |
| Given what you have learned thus far, which of the following statements below do you think is true? | View Page |
| Unexpected Concentrations TDM provides a quantitative measure of the circulating concentration of a drug. The physician determines if the dosage of the drug needs to be adjusted based on this information.If a drug concentration is determined to be outside the therapeutic range, it may be for one of the reasons listed in the table below. Reason Discussion Noncompliance Patients may (intentionally or unintentionally) not take the drug. TDM can thus help monitor compliance. Dosing errors The dose may have been erroneous or inappropriate given the patient's condition. Malabsorption The TDM result will reveal if the drug cannot be absorbed well through the gut and an alternative route of administration will be needed. Drug interactions Many drugs interfere with the absorption or metabolism of other drugs. These interactions will be revealed by TDM. Kidney or liver disease Any pathology that affects elimination will cause an elevation in a drug level that will be unmasked by TDM. Altered protein binding Changes in serum proteins can lead to big changes in the amount of free drug in serum. Variations in the genetics of drug-metabolizing enzymes can also affect drug concentrations in the body. This is the field of pharmacogenomics that will be discussed later in the course. | View Page |
| Drug Concentration Over Time When a drug enters the body, it reaches a peak concentration that starts to fall as the drug is eliminated. The figure on the right shows a typical kinetic with a drug given intravenously (IV). | View Page |
| Half-life The amount of time it takes for a drug's concentration in the body to decrease by 50% is called the drug's half-life (t1/2).The longer a drug's half-life, the slower it is removed from the body. Most drugs are eliminated from the body in 1 to 3 days, but some drugs with longer half-lives can still be detected in the body weeks after the initial dose. The figure below illustrates a typical kinetic pattern for an oral drug. | View Page |
| Drug Elimination Most water-soluble drugs are eliminated from the body through hepatic metabolism. renal filtration, or a combination of the two.An alteration in renal function will have a major effect on the clearance of the drug or its active metabolite(s). Decreased renal function results in elevated serum drug concentrations. | View Page |
| Venipuncture Standard precautions Treat all blood & body fluids as if they were infectious.Always wear gloves during vascular access procedures. | View Page |
| Hematosis A hematoma is a blood clot which forms within the body. It is caused by leakage of blood into the tissues from an injured vein . It will resolve spontaneously.Hematomas are caused by excessive needle trauma to a vein, for example, by a needle which passed entirely through a vein and came out the other side.Apply compression to help stabilize a hematoma.
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| What are bloodborne pathogens? Bloodborne pathogens are infectious micro-organisms which live in the bloodstream.You can be exposed to bloodborne pathogens if you are injured with a contaminated needle.You can also be exposed if your mucous membranes, including eyes, mouth, or the inside of your nose come into contact with contaminated body fluids.
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| Standard precautions Standard Precautions means treating all body fluids and substances as if they were infectious.
Since you can’t tell which specimen may carry a bloodborne pathogen, use appropriate infection control measures during all patient contacts & when handling all specimens.
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| Standard precautions continued Potentially infectious body fluids include:
Blood, Semen, Vaginal Secretion, Peritoneal, pericardial and pleural fluids, and Saliva
Sweat and tears are not generally considered infectious.
It is important to remember that bloodborne pathogens are not transmitted by casual contact, like a handshake.
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| Personal protective equipment An impermeable lab coat should be worn to protect clothing from blood & other body fluids.
Gloves must be worn while drawing blood and during all other patient contact.
Appropriate face masks must be worn during contact with patients in certain types of isolation. A sign posted on the patients door will indicate special protective equipment that may be required prior to entering a patient room. | View Page |
| Integumentary system : function The function of the integumentary system is to:
Protect the underlying tissues from the external environment.
Help regulate body temperature.
Conserve moisture. | View Page |
| White blood cells Leukocytes, or white blood cells, help the body fight infections.
Leukocytes are shown in the photomicrograph of the stained blood smear to the right.
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| Red blood cells Red blood cells contain hemoglobin, which carries oxygen from the lungs to the tissues of the body. Hemoglobin gives blood its red color.
Red blood cells are shown in the photomicrograph of a stained blood smear to the right.
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| Anatomy & physiology: definitions Anatomy is the branch of science concerned with the study of the structure of the body.
Physiology is the branch of science concerned with the study of the function of the body.
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| Explore the Possibilities! The antecubital area of the arm is usually the first choice for routine venipuncture. This area contains the three vessels primarily used by the phlebotomist to obtain venous blood specimens: the median cubital, the cephalic and the basilic veins.Although the veins located in the antecubital area should be considered first for vein selection, there are alternate sites available for venipuncture. These include the top of the hand, the side of the wrist, and the forearm. These sites should only be considered after determining that the veins of the antecubital area cannot be accessed or cannot be used. Vein Location Reason for Choice Placement Direction Median Cubital Mid antecubital fossa Vertical to diagonal Musculature assists in stabilizing vein; very often largest; ease of access Cephalic Thumb side of antecubital fossa Vertical Ease of access; few nerves and tendons in area Basilic Body side of antecubital fossa Vertical to diagonal More difficult to access; proximity of artery, nerves and tendons. Use this vein only as the final alternative. | View Page |
| Tourniquets, Alcohol, and Gauze A tourniquet is used by the phlebotomist to assess and determine the location of a suitable vein for venipuncture. Single-use, latex-free tourniquets are preferred but reusable tourniquets are acceptable. However, if the reusable tourniquet becomes contaminated with blood or body fluid, it must be discarded immediately to avoid the spread of harmful contaminants to other patients. Follow the guidelines established by your facility for cleaning reusable tourniquets.Proper application of a tourniquet will partially impede venous blood flow back toward the heart and cause the blood to temporarily pool in the vein so the vein is more prominent and the blood is more easily obtained. The tourniquet is applied three to four inches above the needle insertion point and should remain in place no longer than one minute to prevent hemoconcentration. If the tourniquet is used during preliminary vein selection, it is best to release the tourniquet after assessing the vein and while you are assembling your supplies. Reapply the tourniquet just before starting the venipuncture; it should then be released soon after the needle has been inserted into the vein and the blood flows into the first tube. If collecting multiple tubes, the tourniquet may remain in place until blood enters the last tube. | View Page |
| Variations in Morphology Many variations in morphology may be seen when examining Wright's stained peripheral blood smears. One method of classifying these variations in white cell morphology is based on the way the body responds to a stimulus, deficiency, or the presence of an inherited defect. This classification falls into three groups:Pathological:
Cells may show abnormalities in appearance and/or function. The body is responding abnormally to a stimulus or inherited defect, resulting in physiological impairment in the patient.
Nonpathological:
Cells may show variation in morphology but their function is normal. Their presence does not cause physiological impairment.
Reactive:
Cells show variation in morphology but are functioning normally in response to a specific stimulus, such as a virus or bacteria. There is a disease process in progress to which the cells are responding. Although the morphology has varied from normal and their presence is significant, the body is responding normally to a stimulus. | View Page |
| Match the following: | View Page |
| Conditions Associated with Hypersegmented Neutrophils There are a number of conditions in which hypersegmented neutrophils may be seen, such as megaloblastic anemias that include folic acid deficiency and pernicious anemia. Individuals who are receiving chemotherapy or have long-term chronic infections may also have hypersegmented neutrophils.The cells seen in these conditions would be classified as pathological since the body is responding abnormally as a result of either a deficiency of a component needed for DNA production or because of the toxic effect that chemotherapy drugs have on DNA. | View Page |
| May-Hegglin Anomaly This blood smear was taken from a patient with the May-Hegglin anomaly. A May-Hegglin Dohle body is indicated by the arrow near the edge of the cytoplasm at the top of the neutrophil. In addition, notice the giant platelet that is indicated by the red arrow, another characteristic of May-Hegglin anomaly. | View Page |
| Classification Vacuoles, toxic granulation and degranulation are classified as reactive since the body is responding normally in an effort to rid itself of infection caused by bacteria. Morphological changes related to aging are also classified as reactive. | View Page |
| Which of the following inclusions have a similar appearance on a Wright's stained smear? | View Page |
| May-Hegglin Like Inclusion Another example of a May-Hegglin-type body. This smear was from a case of pseudo May-Hegglin caused by drugs. Bizarre appearing platelets can also be seen in cases of pseudo May-Hegglin. | View Page |
| Albinism Albinism, one of the striking physical characteristics of Chediak-Higashi syndrome, is also thought to be related to the general dysfunction of cells. Albinism has been specifically related to the aggregation of melanosomes, the pigment producing cells in the body. | View Page |
| More on Dohle Bodies Dohle bodies are seen in a number of conditions, including infections, burns, measles, leukemia and chemotherapy. Dohle bodies are classified as pathological in the sense that they are only present when the body is responding to an unusually severe stress or stimulus. This severe stress may cause the cytoplasm of some cells to mature improperly. Their presence does not aid in the diagnosis of the disorders in which they are found, but they are frequently seen along with toxic granulation and/or vacuoles often present in infections and burns. Recognition is important because their appearance is similar to May-Hegglin bodies, which appear in a rare hereditary disorder called May-Hegglin anomaly. | View Page |
| Alder-Reilly Anomaly (Alder's Anomaly) Alder Reilly Anomaly is a rare autosomal recessive hereditary disorder in which the basic defect involves protein-carbohydrate complexes called mucopolysaccharides. The accumulation of partially degraded (broken down) protein-carbohydrate complexes within the lysosomes account for the larger than normal purple-staining granules seen in the granulocytes, monocytes and/or lymphocytes.
The granules may occur in clusters, rather than diffusely, throughout the cytoplasm as in toxic granulation.
These inclusions may be seen in the bone marrow more frequently than in peripheral blood. The physical characteristics associated with this disorder include gargoylism and dwarfism.
The function of the cells involved is not affected.
This morpholical change would be classified as pathological since the body is responding abnormally even though the function is not affected. | View Page |