Detectionof reverse transcriptase activity in live attenuated virus vaccines.

Background: Safety considerations require that biological products for human use are free from any agent that might pose a potential health hazard. One method to detect the presence of retroviral particles is the reverse transcriptase (RT) assay. This assay is capable of detecting all infectious retrovirus particles, irrespective of genome or protein composition.

[Diagnosis of hepatitis B: is the additional demonstration of viral genome of a prognostic value?].

HBV markers were tested in sera of patients with various clinical and serological states of HBV infection, including patients with delta-infection, and were compared to the detection of HBV-DNA in the sera by hybridization. The results show that high levels of HBV-DNA (much greater than 100 pg/0.1 ml) are mainly found in sera of patients with chronic hepatitis or in early sera of HBs antigen carriers, while 17 of 20 patients with undetectable or trace amounts of DNA in early sera exhibited a self-limiting hepatitis infection.

Isolation of human pathogenic viruses from clinical material on CaCo2 cells.

The use of the epidermal-like cell line CaCo2 and the efficient propagation of viruses from clinical material for diagnostic purposes are reported. Virus replication was observed by cytopathic effects and/or immunofluorescence. The following viruses replicate in CaCo2 cells: enteroviruses (coxsackie B1-B6, poliovirus types 1-3, most echoviruses and coxsackie A viruses), adenoviruses, herpes simplex types 1 and 2, measles, respiratory syncytial, parainfluenza type 2 viruses, and to a lesser extent rubella and mumps viruses.

Cross-reactions of immunoglobulin M and G antibodies with enterovirus-specific viral structural proteins.

We analysed the reactivity of enterovirus-specific human IgM and IgG antibodies with the structural proteins of different enteroviruses by the immunoblot technique. In general, all immunoglobulin G antibodies of the tested sera reacted with capsid polypeptide VP 1 of the viruses tested (echoviruses 9 and 11, coxsackievirus B3 and poliovirus 2). In contrast, enterovirus specific immunoglobulin M antibodies of adults reacted with capsid polypeptides VP 1, VP 2, and/or VP 3 of the viruses mentioned above.

[Possibilities and limits in the detection of nosocomial rotavirus infections].

During an epidemiological survey on rotavirus gastroenteritis in the area of Berne (Switzerland) different virus types were analyzed according to their genome segment pattern. Nosocomial rotavirus infections among pediatric patients were carefully investigated. Possible limitations of such studies are discussed in details.

Reaction pattern of immunoglobulin M and G antibodies to echovirus 11 structural proteins.

The immunoglobulin M and G specific immune response of humans to echovirus 11 proteins during an echovirus 11 outbreak was studied by the immunoblot technique. Whereas immunoglobulin G antibodies were directed most exclusively to the VP 1 protein, the immunoglobulin M antibodies were directed against VP 1, VP 2, and VP 3.

Influence of breast milk on nosocomial rotavirus infections in infants.

To prevent nosocomial rotavirus infections in hospitalized children with various non-gastrointestinal diseases, 30 children (mean age five months) received 200 ml of fresh human milk per day in addition to the normal diet for their age. A matched group of children on formula diet served as a control. Fecal samples were routinely screened for rotavirus by a commercial ELISA test.

Defective viral RNAs in Aedes albopictus C6/36 cells persistently infected with Semliki Forest virus.

A persistent infection of Semliki Forest virus (SFV) has been established in Aedes albopictus C6/36 cells. Only a small number of cells survived the initial infection with this RNA virus and gave rise to a persistently infected culture which produced continuously small amounts of infectious virus. To investigate whether defective viral RNA was analyzed early and late after infection by blot hybridizations.

[Sensitive virologic evaluation in suspected meningitis: study of a radioimmunotest for the detection of IgM antibodies against ECHO 9 and ECHO 11 viruses].

The majority of viral meningitis cases is known to be due to ECHO virus infections on one hand, and mumps on the other. While the latter can be diagnosed by IgM antibody detection from one serum sample in the acute stage, diagnosis of enterovirus infections is by virus isolation and typing. An IgM-antibody test for ECHO 9 and 11 viruses is presented to evaluate the possibility of rapid serological diagnosis of ECHO virus meningitis cases.

Selective disappearance of two secreted host proteins in the course of Semliki Forest virus infection of Aedes albopictus cells.

One secreted host protein of molecular weight 54,000 (SP 54) disappeared (from 24 to 48 h after infection) in Semliki Forest virus-infected Aedes albopictus cell clone C6/36 grown in both Mitsuhashi-Maramorosch basal medium and tissue culture medium 199 and reappeared when cells went into the permanently infected state. C6/36 is a high virus producer showing a cytopathic effect. A second secreted host protein of molecular weight 62,000 (SP 62) was prominent if cell clone C6/36 was grown in tissue culture medium 199.