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Cerebrospinal fluid (CSF) is a clear, plasma-like fluid which circulates around the outside of the brain, in cavities within the brain (ventricles) and in the space surrounding the spinal cord.

Examination of CSF provides vital information which aids in the diagnosis of a wide variety of disorders: benign disordersmeningitisencephalitisbrain abscesssubarachnoid hemorrhagecerebral infract vs. intracerebral hemorrhagemultiple sclerosisGuillian-Barre's syndromespinal cord tumormalignant disordersleukemia CNS involvementmalignant tumors of the brain or spinal cordmetastasis of malignant tumors

The presence of significant amounts of glucose in the urine is called glycosuria (or glucosuria). The amount of glucose present in urine is dependent upon the blood glucose level, the rate of glomerular filtration, and the degree of tubular reabsorption of the sugar. Usually glucose will not be present in the urine until the blood level exceeds 160-189 mg/dl, which is the normal renal threshold for glucose. The main reason for glycosuria is an elevated blood glucose level, called hyperglycemia. Diabetes mellitus is the most common disease that causes hyperglycemia. However, stress, obesity, brain injury, myocardial infarction, hyperthyroidism, pregnancy, and a lowered renal threshold due to kidney damage can all cause glycosuria.

The H & E section of the brain biopsy (left frame)revealed edema of the parencymya with the accumulation of inflammatory cells in the perivascular spaces. The close in view of the exudate (right) frame reveals that the inflammatory exudate is comprised primarily of polymorphonuclear luekocytes. The histologic diagnosis therefore is suppurative meningitis, with culture results necessary to establish the etiologic agent.

Low JC. Donachie W.: A review of Listeria monocytogenes and listeriosis. Veterinary Journal. 153:9-29, 1997Following the initial isolation and description in 1926, Listeria monocytogenes has been shown to be of world-wide prevalence and is associated with serious disease in a wide variety of animals, including man.Our knowledge of this bacterial pathogen and the various forms of listeriosis that it causes has until recently been extremely limited, but recent advances in taxonomy, isolation methods, bacterial typing, molecular biology and cell biology have extended our knowledge. It is an exquisitely adaptable environmental bacterium capable of existing both as an animal pathogen and plant saprophyte with a powerful array of regulated virulence factors.Most cases of listeriosis arise from the ingestion of contaminated food and in the UK the disease is particularly common in ruminants fed on silage.Although a number of forms of listeriosis are easily recognized, such as encephalitis, abortion and septicaemia, the epidemiological aspects and pathogenesis of infection in ruminants remain poorly understood. The invasion of peripheral nerve cells and rapid entry into the brain is postulated as a unique characteristic of its virulence, but relevant and practical disease models are still required to investigate this phenomenon.

Rouquette C. Berche P. The pathogenesis of infection by Listeria monocytogenes Microbiologia. 12:245-58, 1996 Listeria monocytogenes is a Gram-positive bacterium responsible for severe infections in human and a large variety of animal species. It is a facultative intracellular pathogen which invades macrophages and most tissue cells of infected hosts where it can proliferate. The molecular basis of this intracellular parasitism has been to a large extent elucidated. The virulence factors, including internalin, listeriolysin O, phospholipases and a bacterial surface protein, ActA, are encoded by chromosomal genes organized in operons. Following internalisation into host cells, the bacteria escape from the phagosomal compartment and enter the cytoplasm. They then spread from cell to cell by a process involving actin polymerisation. In infected hosts, the bacteria cross the intestinal wall at Peyer's patches to invade the mesenteric lymph nodes and the blood. The main target organ is the liver, where the bacteria multiply inside hepatocytes. Early recruitment of polymorphonuclear cells lead to hepatocyte lysis, and thereby bacterial release This causes prolonged septicaemia, particularly in immunocompromised hosts, thus exposing the placenta and brain to infection. The prognosis of listeriosis depends on the severity of meningoencephalitis, due to the elective location of foci of infection in the brain stem (rhombencephalitis). Despite bactericidal antibiotic therapy, the overall mortality is still high (25 to 30%).

The joining of the HIV and the host cell involves a spike on the HIV envelope and a CD4 molecule on the T-lymphocyte, macrophage, or brain cell.The molecule on the HIV spike is called glycoprotein 120 or gp120. The "120" refers to the molecular weight of the glycoprotein.While the CD4 site is important in viral binding, there is evidence that there are other molecules called co-receptors also involved.These molecules are embedded in the membranes of T-lymphocytes, macrophages, and brain cells. In the T-lymphocyte the abbreviated name of the protein molecule is CXCR4.

The joining of the HIV and the host cell involves a spike on the HIV envelope and a CD4 molecule on the T-lymphocyte, macrophage, or brain cell.The molecule on the HIV spike is called glycoprotein 120 or gp120. The "120" refers to the molecular weight of the glycoprotein.While the CD4 site is important in viral binding, there is evidence that there are other molecules called co-receptors also involved.These molecules are embedded in the membranes of T-lymphocytes, macrophages, and brain cells. In the T-lymphocyte the abbreviated name of the protein molecule is CXCR4.

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 Contact with alternating current (AC) is more likely to cause sustained muscular contraction than contact with direct current (DC). This sustained muscular contraction may prevent the victim from releasing the electrical source, increasing the duration of contact and the amount of electrical energy that is delivered. The resistance that is encountered is dependent on the body tissue that is traversed by the electrical current. Generally, tissues with high fluid electrolyte concentrations will conduct electricity the best. Bone is the most resistant tissue to electrical flow. Skin impedes electrical current, but resistance is dependent on the skin's thickness and moisture. Wet skin can reduce the contact resistance of the body.The degree of electricity-induced injury is also determined by which tissues are in the current pathway. Electrical current that passes through the head or thorax produces the most serious injuries including fatal arrhythmia, direct cardiac damage, respiratory arrest, direct brain injury, and paralysis.