In order to evaluate the statistical significance of an experimental result, it is necessary to have some quantitative estimate of the variability due wholly to errors of measurement. Even though determinations of influenza virus infectivity have long been made using the mouse as a test animal, no detailed analysis of the errors involved has heretofore been carried out. In this paper the result...

Abstract : Foot and Mouth Disease is one of  the important live stocks contagious viral disease caused by Aphtovirus genus ,  that is belong to family RNA virus  picornaviride. The important characteristic of FMD virus is high mutation that give rise to diversity of Antigen in surface of Neutralizing proteins. For this reason FMD virus have 7 distinct serotype and many subtype. Vaccination is o...

The reference method for immunoglobulin G (IgG) avidity determination includes reagent-consuming serum titration. Aiming at better IgG avidity diagnostics, we applied a logistic model for the reproduction of antibody titration curves. This method was tested with well-characterized serum panels for cytomegalovirus, Epstein-Barr virus, rubella virus, parvovirus B19, and Toxoplasma gondii. This ap...

A study was made to establish the reproducibility of end points obtained in the titration of influenza viruses in chick embryos. Six tests were performed, each composed of five replicate titrations of a purified preparation of the PR8 strain of influenza virus. The data from these titrations were subjected to statistical analysis which revealed that the chances are 19 out of 20 that differences...

Because of the peculiar properties of the psittacosis-lymphogranuloma group of viruses, the pattern of multiplication in the allantois of the chick embryo of one of their number, meningopneumonitis virus, was studied. This was done by determination of the changes in its infectivity for mice and chick embryos. Titration of infectivity in embryos proved to be a more sensitive procedure than titra...

Influenza C virus possesses specific neuraminate-O-acetylesterase as a receptor-destroying function. This enzymatic activity of the viral glycoprotein HEF (Hemagglutinin, esterase activity and fusion factor) can be visualized in situ by the use of distinct color substrates. Hereby the localization, as well as the quantity of synthesized HEF protein is detectable. We further developed the estera...

background and objectives: vaccination is the major strategy to protect nurses against infection with hepatitis b virus. however, some nurses do not produce sufficient amount of anti-hbsag antibody required for immunity against infection. chronic occupational stress has been proposed as a risk factor to humoral immunity. given that nursing staff is exposed to occupational stress risk, this stud...

Bluetongue virus (BTV) infects sheep, cattle and other ruminants and is transmitted by Culicoides spp. of biting midges. Virus is typically isolated and characterized by infection of susceptible vertebrate cells that undergo detectable and measurable cytopathic effects. Cell lines derived from C. sonorensis may be useful for virus isolation and studies to better understand BTV replication in th...

Background and Objectives: Vaccination is the major strategy to protect nurses against infection with hepatitis B virus. However, some nurses do not produce sufficient amount of anti-HBsAg antibody required for immunity against infection. Chronic occupational stress has been proposed as a risk factor to humoral immunity. Given that nursing staff is exposed to occupational stress risk, this stud...