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Biomedical subjects

S S Kalter

Publications and source records attributed to S S Kalter.

At least 19 recordsLinked to original sources

Detection of antibody to immunodeficiency viruses by dot immunobinding assay.

The dot immunobinding assay (DIA), a modified enzyme immunoassay (EIA), has been demonstrated to be a highly sensitive and specific assay for the detection of antibody to a number of viruses. Different laboratory procedures are available for detecting antibody to the immunodeficiency viruses; however, these procedures require a certain amount of sophisticated equipment and trained personnel. Further, commercial kits for detecting antibody to human immunodeficiency virus, as now available, are not easy to use in the nonlaboratory setting. The DIA, as described herein, may be formatted to test up to 30 serum samples and is designed to be used in the absence of laboratory equipment. To determine the effectiveness of the DIA as a test kit for the detection of HIV and human T-cell leukemia virus type I (HTLV-I) antibodies, the kit was compared with commercial EIA and Western blot (WB; immunoblot) kits. Testing approximately 1,000 human serum samples for HIV antibody by DIA and EIA revealed a total agreement of 98.1%, a specificity of 99.0%, and a sensitivity of 95.9%. For 804 serum samples tested (200 were tested independently in two laboratories), eight results were discrepant: four DIA negatives which were EIA borderline positive and four DIA positives which were EIA negative. Testing the eight discrepant sera by immunofluorescence assay and WB resulted in their being either negative or indeterminate. The four DIA positives were indeterminate by WB. Close agreement was obtained when the remaining sera were compared by DIA, EIA, and WB. Of interest was finding that the DIA results compared favorably with those obtained by WB. Twenty-six suspect HTLV-I-positive serum samples tested by DIA also gave results comparable to those obtained by EIA and WB.

Blotting, Western

The evolutionary watershed of susceptibility to gonococcal infection.

Gonococci do not cause genital infection in any convenient experimental animal, but all too easily cause genital infection in humans. To determine the 'evolutionary watershed' of gonococcal infections (the point on the evolutionary tree at which susceptibility to gonococcal infection begins) we extended previous studies of the interaction of gonococci with animal oviduct mucosa to include chimpanzees and baboons. Gonococci attached to, damaged, and invaded the oviduct (fallopian tube) mucosa of chimpanzees (which are apes) but not the oviduct mucosa of baboons (which are monkeys). Thus, the pattern of gonococcal infection in chimpanzees was identical to that in humans, whereas the pattern in baboons was like that in other animals. These studies indicate that the point in evolution at which susceptibility to gonococcal infection commences is between baboons and chimpanzees (or between monkeys and apes). Susceptibility to gonococcal disease appears to require the presence on genital epithelial cells of receptors for gonococcal ligands such as pili, receptors for gonococcal lipopolysaccharide, or both. The physiological role of these receptors may be to interact with more useful, as yet unidentified molecules.

Animals

Viral battery testing in nonhuman primate colony management.

Good colony management is associated with monitoring of animals for infectious agents. Of major current concern are B virus and simian AIDS (SAIDS) viruses. However, other viral agents frequently cause serious disease outbreaks which can be avoided if their presence is detected sufficiently early. The recent development of a rapid, sensitive and specific diagnostic test system, i.e., the dot immunobinding assay (DIA) permits the monitoring of a colony for many of the viruses that pose problems. By employing battery type testing using a panel of appropriate viral antigens, investigators are able to detect the increased presence of viral agents of concern and take necessary measures to prevent extension of the problem.

Animal Husbandry

Primate viral diseases in perspective.

The recent occurrence of fatal Herpesvirus simiae (B virus) infection in human subjects has again focused the attention of primatologists on this virus. B virus, however, is only one of a number of viral diseases that plays a role in primate colony management. This report is to emphasize to the primatologist a number of viruses other than H. simiae, with high morbidity and mortality rates, of importance for health management of nonhuman primate animal colonies. This concept is supported by the recent occurrence in colonies of nonhuman primates of simian hemorrhagic fever virus, SA8, herpesvirus, respiratory syncytial virus, encephalomyocarditis virus, Ebola virus, and simian immunodeficiency viruses.

Animals

Dot immunobinding assay compared with enzyme-linked immunosorbent assay for rapid and specific detection of retrovirus antibody induced by human or simian acquired immunodeficiency syndrome.

A rapid, specific, and sensitive modification of the dot immunobinding assay was compared with the standard enzyme immunoassay as a screening procedure for the detection of antibody in human or simian acquired immunodeficiency syndrome. Comparative testing with the available enzyme immunoassay procedures, either in commercial kit form or as provided by diagnostic laboratories, indicated excellent correlation. Ease of operation and cost are key features of the dot immunobinding assay procedure.

Acquired Immunodeficiency Syndrome

Serodiagnosis of rabies by dot immunobinding assay.

A dot immunobinding assay that uses inactivated antigen for the detection of rabies viral antibodies was compared with the rapid fluorescent focus inhibition test. Results of testing pre- and postvaccination sera from humans (n = 33) and canines (n = 22) were identical for both tests. Endpoint titers of positive sera also were approximately the same by both methods. When a mouse monoclonal antibody was used, the dot immunobinding assay antigen was shown to possess detectable rabies virus glycoprotein and core antigens.

Animals

A dot-immunobinding assay on nitrocellulose with psoralen inactivated Herpesvirus simiae (B virus).

An enzyme-immunoassay performed with Herpesvirus simiae (B virus) and H. simplex antigens inactivated with a psoralen derivative and long-wavelength ultraviolet light irradiation is described. Although B virus is a known human pathogen requiring extreme care in its handling, the use of inactivated antigens in the test allows its performance without biosafety containment. The test utilizes nitrocellulose sheets dotted with antigen for the assay of antibody against B virus in nonhuman primate sera. Antigen-antibody complexes are detected visually as red dots by the use of enzyme-conjugated antiglobulin second antibody and a substrate that produces an insoluble product. The test is more rapid, sensitive and specific than the serum neutralization test it is intended to replace. Of 150 macaque monkey sera tested, 83 were negative by the enzyme and neutralization tests, 56 were positive by both tests and 11 were positive by enzyme-assay but negative by neutralization. Positive sera reacted with both simian and human viral antigens in the enzyme assay but with greater intensity against B virus. Absorption with H. simplex removes reactivity with this virus without reducing the B virus response.

Antibodies, Viral

Cell-mediated immunity in cat-scratch disease.

The importance of cell-mediated immunity in cat-scratch disease (CSD) is suggested by the positive skin test reactions and granulomatous histopathology noted in patients with this disease. However, an earlier investigation found that lymphocytes from patients with CSD and control subjects were equally unresponsive in vitro to cat-scratch antigen. In contrast, we found that 16 patients with CSD had significantly increased lymphocyte transformation responses to cat-scratch antigen when patients were compared to control subjects. This cell-mediated immune response may be directed against nonviable bacteria in the involved lymph nodes and may be the major mechanism responsible for the granulomatous reaction and clinical features of CSD.

Adolescent

Rapid dot-immunobinding assay on nitrocellulose for viral antibodies.

A procedure is described for the routine laboratory diagnosis of viral serum antibodies. Antigens are dotted on nitrocellulose strips or sheets, and sera are applied on absorbent paper strips. Antigen-antibody complexes are detected with enzyme-conjugated antiglobulin and development of a colored, insoluble substrate product. The test allows processing of multiple sera in one 3- to 5-h operation and is equal to or more sensitive than serum neutralization, hemagglutination inhibition, and fluorescent antibody assays. Highly infectious viruses inactivated with a psoralen derivative and long-wavelength UV light irradiation can be used as antigens, allowing the study of human pathogens. Although the test detects cross-reacting, group-specific herpesvirus antigens, the intensity of the antibody reaction is greatest with type-specific antigens. Preliminary data suggest that the technique will be useful for the rapid typing of viruses from clinical specimens.

Animals

Herpes simplex virus complement fixing antibody and herpes B virus serum neutralizing antibody in sera of wild and laboratory-bred cynomolgus monkeys.

The result of the complement fixation (CF) test for the antibody to herpes simplex virus (HSV) in sera of the cynomolgus monkeys was compared with that of the neutralization test (NS) for the antibody to herpes B virus (HBV) in the same sera. Fifty-seven (74%) of 77 wild-originated monkeys were positive for HSV-CF, while 65 (84%) of the 77 animals were positive for HBV-SN. All of the 57 CF positive cases were also positive for HBV-SN. On the other hand, 30 (75%) of 40 laboratory-bred monkeys had neither HSV-CF antibody nor HBV-SN antibody. Remaining 10 of the 40 laboratory-bred animals were positive for HSV-CF. However, no HBV-SN antibody was detected in nine of the 10 HSV-CF positive animals. These results suggest that the HSV-CF test may be as satisfactory as the HSV-SN test as a practical measure for rough screening of HBV infection in the cynomolgus monkey in laboratories having no containment unit for handling HBV.

Animals

Dot immunobinding assay of viral antigen and antibodies.

A dot-immunobinding assay for the rapid and specific detection of viral antibody as well as the identification of a virus is described. Based on the use of nitrocellulose membranes for the adsorption of viral protein, this test may be used to detect the presence of virus antibody or identify an isolate within 4 to 6 hours. Use of goat anti-human IgG-alkaline phosphatase followed by a naphthol-AS-MX-phosphate: Fast Red substrate permits visual detection of a positive reaction. The use of psoralen inactivated herpes B virus permits the incorporation of this virus into the battery of test antigens.

Animals

Development of molecular probes for simian herpesvirus detection.

A number of serologic procedures are available for specifically determining past infection due to H. hominis, or H. simiae (B virus). A herpesvirus isolated from primate tissues, however, does not lend itself to specific identification. Procedures currently in routine use simply do not provide an unequivocal identification of the isolate. We have previously demonstrated that H. simiae contain polypeptide and glycoprotein antigens distinct from those of other herpesviruses. At selected intervals, infected cells and controls were harvested after being both pulsed as well as continuously labelled from 4-24 hours post infection with 3H-glucosamine. 3H-mannose, and 3H-L-amino acid mixture. Between 40-45 infected cell polypeptides were observed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) with 7-11 glycoproteins noted. Analysis of the bands by electroblot utilizing anti-B virus sera showed the presence of eleven reactive bands within this molecular weight range from preparations in infected Vero and HEp-2 cell lines. Glucosamine labelled major glycoproteins migrated at 130K, 100K, 95K, 65K, 39K; mannose moieties migrated at 95K and 65K. SDS-PAGE profiles of B-virus when reacted with anti-gA/gB from HSV-1 and HSV-2 showed weak reactivities on the 125-130K complex. Anti-VP5 from HSV-1 failed to indicate any reactivity. Three polypeptides were revealed by SDS-hydroxylapatite analysis of the 130K complex with approximate molecular weights of 115K, 123K, and 130K; the 115K and 123K bands reacted with antisera prepared against gA/gB from HSV-1 and HSV-2, but not to anti-IgC or anti-2gC.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Sensitivity of equine herpesviruses 1 and 3 in vitro to a new nucleoside analogue, 9-[[2-hydroxy-1-(hydroxymethyl) ethoxy] methyl] guanine.

The following members of the Herpetoviridae family were tested to determine their sensitivities to the new antiviral drug, BIOLF-62: equine herpesvirus types 1 and 3, human herpesvirus types 1 and 2, swine herpesvirus, bovine herpesvirus type 4, feline herpesvirus, canine herpesvirus, and herpes simiae virus. Equine herpesviruses 1 and 3, human herpesviruses 1 and 2, and herpes simiae virus were all sensitive to BIOLF-62 at concentrations of less than 0.55 micrograms/ml. Equine herpesvirus types 1 and 3 were particularly sensitive, viral median effective dose (ED50) concentrations of the drug being only 0.033 and 0.16 micrograms/ml, respectively. Such high antiviral potency and low cell toxicity indicate that BIOLF-62 might be useful in the treatment of infected animals.

Acyclovir