Infectious

Methods to Detect and Quantitate Viral Agents in Fluids. In order to assess the effectiveness of membrane filtration the abihty to quantitate the amount of vims present pre- and post-filtration is critical. There are a number of techniques used. The method of choice for filter challenge studies is the plaque assay which utilizes the formation of plaques, localized areas in the cell monolayer where cell death caused by viral infection in the cell has occurred on the cell monolayer. Each plaque represents the presence of a single infectious vims. Vims quantity in a sample can be determined by serial dilution until the number of plaques can be accurately counted. The effectiveness of viral removal may be determined, as in the case of bacterial removal, by comparing the vims concentration in the input suspension to the concentration of vims in the effluent. 

The plaque assay is desirable because it is very sensitive and only detects infectious viral particles. However, there are viral agents which cannot be supported by cell lines. In these cases other methods must be used. The polymerase chain reaction (PGR), which amplifies DNA or RNA from viral agents, can be used to detect the presence and quantity of viral agents. The amount of RNA or DNA target in the initial sample can be determined by competitive PGR where the quantity of amplified product is compared to a control PGR product where the initial amount of target is known. Quantification is also possible by an end-point dilution method similar to that used to determine a tissue culture infections dose. PGR methods can be very sensitive however. 

Staphylococcal a-hemolysin is another widely studied pore-forming toxin. It is used by infectious bacteria to perforate host animal cells by a mechanism that is distinct from that of gramicidin. Several aspects of the stmcture and function of this heptameric protein complex have been smdied. 

The singularity of MAbs and the ease of mass production appeared to be the answer to rapid development of highly specific immunoassays. Companies were formed to produce MAbs and incorporate them into assays. In fact, such assays have been developed and have proved very successful for infectious diseases, hormones, and other clinical analytes. 

As the result of high specificity and sensitivity, nucleic acid probes are in direct competition with immunoassay for the analytes of some types of clinical analytes, such as infectious disease testing. Assays are being developed, however, that combine both probe and immunoassay technology. In such hybrid probe—immunoassays, the immunoassay portion detects and amplifies the specific binding of the probe to a nucleic acid. Either the probe per se or probe labeled with a specific compound is detected by the antibody, which in turn is labeled with an enzyme or fluorophore that serves as the basis for detection. 

Melatonin thus could represent a new approach to the physiological control of stress and stress-related infectious diseases (48). 

D. Tracey and K. Richard, "Mechanisms of Immuno stimulation by Pyrimidiuones," iu Immunopharmacology of Infectious Diseases Uaccine Mdjuvants and Modulators of Non-specific Resistance, Alan R. Liss, Inc., 1987, pp. 279—289. 

General Antibacterial Properties. In the clinical control of bacterial infectious disease, the aminoglycosides gentamicin, tobramycin, amikacin, netilmicin, and to a lesser extent, dibekacin and isepamicin are most commonly used for the treatment of serious infections involving aerobic or facultative gram-negative baciUi, especially in the compromised host. This usage is discussed in the Hterature (44—51). 

Members of the aminoglycoside class of antibacterial antibiotics retain an important role in the control of bacterial infectious disease, especially in... 

Clinically, GM-CSF or G-CSF have been used to accelerate recovery after chemotherapy and total body or extended field irradiation, situations that cause neutropenia and decreased platelets, and possibly lead to fatal septic infection or diffuse hemorrhage, respectively. G-CSF and GM-CSF reproducibly decrease the period of granulocytopenia, the number of infectious episodes, and the length of hospitalization in such patients (152), although it is not clear that dose escalation of the cytotoxic agent and increased cure rate can be rehably achieved. One aspect of the effects of G-CSF and GM-CSF is that these agents can activate mature cells to function more efficiently. This may, however, also lead to the production of cytokines, such as TNF- a, that have some toxic side effects. In general, both cytokines are reasonably well tolerated. The side effect profile of G-CSF is more favorable than that of GM-CSF. Medullary bone pain is the only common toxicity. 

Decontamination is a procedure to render safe for handling, disposal, or the subsequent processing of an article that may contain a large amount of potentially infectious organisms. Decontamination and sterilization are similar procedures, except that in the former case the bioburden is higher. In both cases, all organisms present are destroyed. However, decontamination is not expected to result reHably in the 10 probabiHty of microbial survival, as in sterilization, because of the higher bioburden. Decontamination may include sanitization and disinfection steps, but it most frequentiy involves sterilization... 

A vaccine is a preparation used to prevent a specific infectious disease by inducing immunity in the host against the pathogenic microorganism. The practice is also called immunization. The first human immunization was performed in 1796 by Edward Jenner in England which led to the discovery of smallpox vaccine. However, classical vaccinology developed 100 years later, after the work by Louis Pasteur demonstrated that microorganisms are causes of diseases. 

Vaccines are used in either the general population of children or adults or for special groups. Recommendations for vaccine usage are made by the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control. The Committee on Infectious Diseases of the American Academy of Pediatrics (Redbook Committee) also makes recommendations for infants through adolescents, and the American Academy of Family Physicians makes recommendations for adults. An excellent review of vaccine history, development, usage, and related regulatory issues is available (2). 

P. J. Baker, ed.. National Institute of Allergy and Infectious Diseases, The Jordan Report, Accelerated Development of Vaccines, 1993, NIH, Bethesda, Md. 

World Pat. 9529700-Al (1995), B. E. Haynes and T. J. Palker, "New Peptide Corresponding to HIV Sequences Used for Induciug Protective Immunity to HIV and iu the Treatment of e.g. Auto-Immune Disease Infectious Diseases and Tumors" (to Duke University). 

H. C. Neu, in J. C. Petrie, ed.. Gastrointestinal, Haematological and Infectious Disease Therapy, Elsevier Science PubHshers, Amsterdam, The Netherlands, 1985, p. 215. 

---