Mount Information and Courses from MediaLab, Inc.

The first step in treating patients with CDAD is to discontinue the causative agent wherever possible. The choice for initial antibiotic therapy depends on the severity of disease. Oral vancomycin or metronidazole remain the mainstays of therapy for C. difficile infection, with vancomycin reserved for patients with more severe disease and/or those who have not responded to metronidazole. Metronidazole is currently favored in guidelines from the CDC on the basis of cost and concern that oral vancomycin promotes colonization with vancomycin-resistant Enterococcus. Oral fluids (water and electrolytes) may be necessary to counteract fluid loss as a result of excessive diarrhea, which can quickly lead to dehydration. Patients with fulminant disease and toxic megacolon may require colectomy. Recurrence of C. difficile infection (CDI) is becoming an increasing problem. Most recurrences happen 7 - 14 days after completion of therapy, suggesting relapse rather than re-infection. If a patient develops a second episode of CDI following initial successful treatment, it is recommended that if possible, the same drug be used to treat the second episode. Contributing factors to recurrent CDI include: Continuing exposure to organisms either through re-infection (via contaminated environment or poor hand hygiene) or an endogenous source, such as C. difficile spores in GI tract. An inability to mount an adequate anti-Toxin A IgM and/or IgG antibody response (i.e., poor host immune response); a likely reason why CDI affects an increasingly elderly population. Unfortunately a vicious cycle can arise whereby the initial treatment prescribed, vancomycin or metronidazole, significally disrupts normal colonic flora reducing colonization resistance and leaving the patient vulnerable to the next recurrent episode.Other treatments including the use of probiotics or anion-exchange resins to absorb toxins, may work in some cases but none work in every case.The goal of all treatment is to reestablish normal colonic flora so as to control C. difficile (over)growth.

The following is a list of materials needed for semen analysis. Laboratories will differ slightly in the equipment used. Use of this equipment will be described further in the later pages of this course. Materials needed include:graduated test tube or serological pipets with safety bulb to measure volumepH paper in neutral to basic range (e.g. 7.2-8.8)counting chamber and/or automated counting machineglass slides and coverslips for wet mount if motility and sperm count are to be assessed separatelyhand counterif dilution is donediluting fluid calibrated automatic pipetspositive pressure pipets and glass boreslight microscope with phase contrast objectives for sperm count and bright field objectives for morphology assessmentglass slides and fixative for morphology slidesset-up for performing Papanicolaou or other morphology stainingReference materials, such as the most current WHO laboratory manual for the examination and processing of human semen, a publication of the World Health Organization.

Some professionals believe that sperm counts done by hemocytometer are not accurate because of the need to dilute the viscous semen prior to counting. There are several other counting methods available to assess sperm concentration. The advantages of the following methods are: The specimen does not have to be diluted Motile and non-motile sperm can both be counted avoiding the need for wet mount evaluation of motile cells. Note that counting moving sperm can be difficult and takes significant practice to avoid error. Makler (Zygotek Systems, Inc.). An undiluted sample is placed on the chamber and covered with the coverglass. Ten squares on the grid contain 0.000001ml. CellVu (Millennium Sciences, Inc). Two sides of a special slide are loaded with a drop of undiluted semen. Coverslips with special grids are placed on top of the sperm according to manufacturer's directions. Sperm on both sides are counted.MicroCell (Conception Technologies) has two chambers on a single, disposable slide. A special eyepiece with a grid is needed for counting.

WHO 5th edition recommends reporting these categories of movement:Progressive motility: Spermatozoa are moving actively (not necessarily rapidly), either linearly or in a large circle. Several examples of progressive motility can be seen in the attached video.Non-progressive motility: There is an absence of progression, e.g., swimming in small circles; the head is barely moving as the result of the flagellar movements; only the flagellar movement is noted. An example of non-progressive motility can be viewed on the following page.Immotility: Total absence of movement Complete the assessment of progressive motility in the area of observation, followed by non-progressive motility, and finally immotility.The lower reference limit for progressive motility is 32%. The lower reference limit for total motility (progressive + non-progressive) is 40 %. This video and the video on the following page are used with permission of Kokopelli Technologies, LLC.

When the urine cools or when the wet mount begins to dry, Trichomonas begins to lose its characteristic motility and may easily be misinterpreted as white cell or epithelial cell.