Infection Kinetics

IE-1, IE-2 Expression kinetics, infection phenotype Inhibition of TNF-induced apoptosis Zhu et al. 1995... 

It is necessary to estabUsh a criterion for microbial death when considering a sterilization process. With respect to the individual cell, the irreversible cessation of all vital functions such as growth, reproduction, and in the case of vimses, inabiUty to attach and infect, is a most suitable criterion. On a practical level, it is necessary to estabUsh test criteria that permit a conclusion without having to observe individual microbial cells. The failure to reproduce in a suitable medium after incubation at optimum conditions for some acceptable time period is traditionally accepted as satisfactory proof of microbial death and, consequentiy, stetihty. The appHcation of such a testing method is, for practical purposes, however, not considered possible. The cultured article caimot be retrieved for subsequent use and the size of many items totally precludes practical culturing techniques. In order to design acceptable test procedures, the kinetics and thermodynamics of the sterilization process must be understood. 

Recently, Tsakala et al. (90) formulated pyrimethamine systems based on several lactide/glycolide polymers. These studies were conducted with both microspheres (solvent evaporation process) and implants (melt extrusion process). In vitro studies indicated that pyrimethamine-loaded implants exhibited apparent zero-order release kinetics in aqueous buffer whereas the microspheres showed an initial high burst and considerably more rapid drug release. In vivo studies in berghi infected mice confirmed that the microspheres did not have adequate duration of release for practical application. However, the implants offer promise for future clinical work as more than 3 months protection was observed in animals. 

Rolinski B, Bogner JR, Sadri 1, Wintergerst U, Goebel FD (1997) Absorption and elimination kinetics of zidovudine in the cerebrospinal fluid in HIV-1-infected patients. J Acquir Immune Defic Syndr Hum Retrovirol 15(3) 192-197... 

D13. van Deuren, M., Kinetics of tumour necrosis factor-alpha, soluble tumour necrosis factor receptors, interleukin 1 -beta and its receptor antagonist during serious infections. Eur. J. Clin. Microbiol. Infect. Dis. 13,12-16 (1994). 

E10. Engel, A Kern, W. V., Miirdter, G., and Kern, P Kinetics and correlation with body temperature of circulating interleukin-6, interleukin-8, tumor necrosis factor alpha and interleukin-1 beta in patients with fever and neutropenia. Infection 22, 160-164 (1994). 

There is good evidence, for a number of helminth species, that different parasite lines vary in their infection characteristics in hosts, much of which is reviewed by Read and Viney (1996). For example, different isolates of Trichinella spiralis vary in the kinetics of their primary infection in the same mouse strain. Crucially, these differences are removed when mice are immunosuppressed (Bolas-Fernandez and Wakelin, 1989). Analogous observations have been made for Trichuris muris in mice. Different isolates differed in the kinetics of infection and expulsion. However, in immunosuppressed mice, all isolates had similar fecundity (Bellaby et al., 1995). Combined, these observations show immune-dependent variation between parasite lines in their infection kinetics. 

Taken as a whole, these observations show that parasite lines differ in an immune-dependent manner in their infection/expulsion kinetics. Furthermore, there is heritable variation in survival and fecundity in previously exposed hosts and quantitative variation in the immune response that selected parasite lines elicit. Again, taken as a whole, these observations have the necessary corollary that variation in these traits exists not only in laboratory-maintained isolates but also in helminth species in nature. The phenotypes under consideration here (infection/expulsion kinetics, survival, fecundity) are multifactorial life-history traits. Understanding the basis of variation in the components and interplay of these complex, immune-responsive phenotypes must be of crucial relevance to understanding the immunology of infections of parasitic nematodes. This is of particular relevance in view of current attempts to develop immunological methods of nematode control. 

The third example considered the interaction of life-history traits (survival rates, fecundity, immunogenicity) with an environmental factor specific to parasites, namely the host immune system. Here phenotypic diversity in response to environmental conditions (host immunity) is not so readily apparent. To observe phenotypic diversity, different parasite lines need to be compared in their kinetics of infection and, to show immune-dependence, these must be complemented by control experiments in immunosuppressed hosts. Experiments seeking to select on this diversity... 

Hoste, H. (1989) Trichostrongylus colubriformis epithelial cell kinetics in the small intestine of infected rabbits. Experimental Parasitology 68, 99-104. 

Symons, L.E.A. (1965) Kinetics of epithelial cells and morphology of villi and crypts in the jejunum of the rat infected with Nippostrongylus brasiliensis. Gastroenterology49, 158-168. 

Lawrence, B.R and Vorderstrasse, B., A kinetic study of the recall response to influenza vims infection in mice exposed to the immunosuppressive pollutant dioxin, Toxicol. Sci., 79, 304, 2004. 

Fujita Y, Zenitani B, Nakao Y, Matsubara T (1972) Bacteriological studies on diseases of cultured laver. II. Bacteria associated with diseased laver. Bull Jap Soc Sci Fish 36 565-569 Gachon CMM, Kupper H, Kupper FC, Setlik I (2006) Single-cell chlorophyll fluorescence kinetic microscopy of Pylaiella littoralis (Phaeophyceae) infected by ChytricUum pofysiphoniae (Chytridiomycota). Eur J Phycol 41 395—403... 

Early detection of mastitis and immediate treatment reduces pathologic damage and increases the likelihood of eliminating the infection. Because therapy is given without identification of the pathogen involved, a product with a broad antibacterial spectrum is essential (4. The desirable kinetic and other properties of an intramammary antibiotic product for treatment in lactation have been summarized by Ziv (23). 

Alice et al studied the turnover kinetics of Listeria OTonocytogenex-secreted p60 protein (a murein hydrolase) by host cell cytosolic proteasomes. J774 cells, seeded in flasks and incubated overnight in culture medium, were infected with log-phase cultures of E. monocytogenes for 30 min, washed, and incubated in culture medium for 3 h, with gentamicin (50 tg/ml) added after the first 30 min to inhibit extracellular bacterial growth. Cells then were washed and placed in methionine-free medium with spectinomycin, gentamicin, the eukaryotic protein synthesis inhibitors [cycloheximide (50 tg/mL) and anisomycin (30 tg/ml),] and 25 dVI calpain inhibitor I. After 30 min, [ S]methionine was added, and the cells were pulse-labeled for periods of 20 to 60 min. Cells... 

Pharmacologic factors include (1) the kinetics of absorption, distribution, and elimination (2) the ability of the drug to be delivered to the site of infection (3) the potential toxicity of an agent and (4) pharmacokinetic or pharmacodynamic interactions with other drugs. 

Padilla, A., Govezensky, T., Sciutto, E., Jimenez-Garcia, L.F., Gonsebatt, M.E., Ramirez, P. and Larralde, C. (2001) Kinetics and characterization of cellular responses in the peritoneal cavity of mice infected with Taenia crassiceps. Journal of Parasitology 87, 591 -599. 

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