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Biomedical subjects

J L Melnick

Publications and source records attributed to J L Melnick.

At least 325 records · Page 18Linked to original sources
PubMed1970

Seroepidemiological and ecological studies of the adenovirus-associated satellite viruses.

The seroepidemiology of the defective adenovirus-associated satellite viruses was studied by use of a neutralization test that has been shown to be much more sensitive than the complement-fixation (CF) test. Less than 25% of the subjects in any age group were positive for any type of satellite virus CF antibody. The neutralization test revealed serological evidence of satellite infection in almost 80% of the subjects in some age groups. Studies of geometric mean antibody titers by neutralization showed that antibody against type 1 and the type 2-3 complex reached peak levels at 2 to 3 years of age; antibody against types 2 and 3 reached mean titers of 500 to 800, whereas mean antibody levels of only 200 were found for type 1. Type 4 antibodies were rarely noted in human sera. In a companion study in monkeys, monospecific responses to types 1 and 4 were found only in rhesus and green monkey sera, respectively. These data suggest that the type 2-3 complex may be the only naturally occurring satellite serotype which infects man and that antibodies noted against types 1 and 4 may be the result of cross-reactions. No satellite viruses were isolated from throat or rectal swabs of 100 children between 6 months and 3 years of age. However, the patterns of adenovirus and enterovirus isolations from these specimens were typical of previous studies in this laboratory.

Journal Article↗
PubMed1970

Virus isolations from sewage and from a stream receiving effluents of sewage treatment plants.

In order to detect viruses in sewage or streams, it is first necessary to concentrate the virus present in the fluid sample. Available methods are not readily manageable for concentrating virus from large volumes of fluid, and have not always yielded high recovery rates. In the study described in this paper, a method for concentration of viruses by adsorption on insoluble cross-linked maleic anhydride polyelectrolytes has been utilized to survey the viral flora of sewage and of a stream receiving sewage effluents, in a residential area of Houston, Texas. On a single day the virus flow at different points along the stream varied from 304 000 to 6 014 000 PFU/min. From 84 samples each of 1 US gal, 14 520 isolates were obtained, chiefly echovirus type 7 and polioviruses of all 3 types, some of them with characteristics of virulent wild strains. With virus isolation rates as high as those achieved, it is now possible to monitor virus in natural waters more effectively.

Enterovirus B, Human↗
PubMed1970

WHO collaborative studies on enterovirus reference antisera. Third report.

This paper smmarizes the results of the third part of co-operative studies undertaken by the WHO International Reference Centre for Enteroviruses and a number of WHO Regional Virus Reference Centres and WHO Virus Collaborating Laboratories and other laboratories in a comprehensive testing programme of enterovirus equine antisera prepared for long-term use as reference antisera. The studies were designed to appraise the specificity of the immune serum of horses inoculated with prototype enteroviruses (coxsackie-viruses A1, A5, A6, A12 and A22 and echoviruses 5, 6, 13-16, 18-20, 22-26, 29 and 32). Tests for neutralizing antibody were performed not only against the homologous viruses but also against regional homotypic strains. Tests for heterotypic antibody were made against the entire group of enteroviruses (except enterovirus 68), reoviruses 1-3, and adenoviruses 1-11, 13-17 and 19-22. Final vials of the dried serum were provided for the tests. Each serum sample represented a pool of the individual bleedings taken from a group of horses before and after immunization with each virus antigen. The results showed that the homologous geometric mean titres of 9 of 16 echovirus immune sera were 10 000 or above while the other 7 ranged from 2000 to 8000. The homologous antibody titre of one coxsackievirus type A serum was about 2000 while the titres of the other 4 type A sera ranged from about 5000 to 15 000. All corresponding pre-inoculation sera were negative. The results of the homotypic tests, though limited in number, showed the usefulness of the sera. Data on heterotypic antibody titres, if any, are recorded for gidance in the use of the sera. Co-operative testing of 19 additional enterovirus equine sera is now in progress.

Animals↗
PubMed1969

Plus and minus single-stranded DNA separately encapsidated in adeno-associated satellite virions.

Based on physical and chemical determinations, the mnolecular weight of the type 4 adeno-satellite virus is 5.4 X 10(6) daltons, and the virion contains 1.4 X 10(6) daltons of DNA. Denaturation and renaturation studies indicate that the viral genome is a single-stranded DNA molecule and that each virion contains either a minus or a plus strand. Upon extraction, the minus and plus strands unite to form double-stranded DNA molecules with no obvious excess of unpaired strands.

Adenoviridae↗