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Biomedical subjects

P Gerber

Publications and source records attributed to P Gerber.

At least 91 records · Page 5Linked to original sources
PubMed1982

Comparison of the Raji cell line fluorescent antibody to membrane antigen test and the enzyme-linked immunosorbent assay for determination of immunity to varicella-zoster virus.

A prospective study was performed comparing the fluorescent antibody to membrane antigen (FAMA) test and the enzyme-linked immunosorbent assay (ELISA) for identifying susceptibility and seroconversion to varicella-zoster virus (VZV) infection. A total of 75 sera were collected from index cases and from sibling and parent contacts in 10 families. Varicella-zoster virus-infected human diploid embryonic fibroblasts and continuous lymphoblastoid cells (Raji cells) were compared as indicator cells in the FAMA test. Equivalent results were obtained with both types of cell. Results of the FAMA test and the ELISA were identical in two ways. (i) The same 11 individuals were initally defined as susceptible (seronegative), and 9 of them (82%) developed fourfold rises in antibody titers, clinical varicella, or both. (ii) Of 21 immune (seropositive) individuals, 4 developed fourfold antibody rises by FAMA tests, and 3 of these 4 responded by ELISA. Infection was asymptomatic in these individuals. The geometric mean titer by ELISA was significantly higher than by the FAMA test. The results indicated that the ELISA and the FAMA test have similar capacities to define susceptibility to varicella-zoster virus and that subclinical infection with varicella-zoster virus may be common.

Antibodies, Viral↗
PubMed1982

DNA of herpesvirus pan, a third member of the Epstein-Barr virus-Herpesvirus papio group.

The DNA of herpesvirus pan, a primate B-lymphotropic herpesvirus, shares about 40% well-conserved sequence relatedness with Epstein-Barr virus (EBV) and herpesvirus papio DNAs. Labeled cloned fragments from the EBV recombinant DNA library were cross hybridized to blots of EcoRI, XbaI, and BamHI restriction endonuclease fragments of herpesvirus pan DNA to identify and map homologous sequences in the herpesvirus pan genome. Regions of colinear homology were demonstrated between 6 x 10(6) daltons and 108 x 10(6) daltons in the DNAs. The structural organization of herpesvirus pan DNA was similar to the format of Epstein-Barr virus and herpesvirus papio DNAs. The DNA consists of two domains of largely unique sequence complexity, a segment US of 9 x 10(6) daltons and a segment UL of 88 x 10(6) daltons. US and UL are separated by a variable number of tandem repetitions of a sequence IR (2 x 10(6) daltons). There was homology between DNA which mapped at 26 to 28 x 10(6) daltons and 93 to 95 x 10(6) daltons in UL. The terminal reiteration component, TR, of herpesvirus pan DNA and sequences which mapped to the left of 6 x 10(6) daltons and to the right of 108 x 10(6) daltons had no detectable homology with the corresponding regions of Epstein-Barr virus DNA.

Base Sequence↗
PubMed1982

Persistence of transforming and nontransforming Epstein-Barr virus in high passages of P3HR-1 cell lines.

At least three laboratories have reported that the P3HR-1 line, which had originally produced transforming Epstein-Barr virus (EBV), now produces only the nontransforming variant. Studies to determine whether these findings were universal or a consequence of specific cell lines or culture conditions were undertaken in P3HR-1 cultures of identical HLA types from five sources. All of the EBV preparations derived from cell lines cultured at 32, 34, and 35 degrees C transformed cord blood lymphocytes, whereas virus propagated at 37 degrees C did not usually transform. Furthermore, indirect immunofluorescence revealed that a monoclonal antibody directed against transforming EBV membrane glycoprotein bound to 10-12% of the P3HR-1 cells that had been continuously propagated at 34 degrees C, but the antibody did not bind to the same cells cultured at 37 degrees C. Although virus expression was completely repressed in transformed cord blood cells, transforming virus could be rescued by superinfection with nontransforming P3HR-1 EBV. Cells transformed with P3HR-1 virus induced poorly differentiated lymphomas in athymic nude mice after seven or eight passages. Whether all P3HR-1 cells have the potential to produce detectable quantities of transforming virus remains to be determined.

Animals↗
PubMed1981

[Humidifier lung].

Breathing air from a humidifier or an air conditioning unit contaminated by various microorganisms can cause an acute lung disease involving fever, cough and dyspnea, termed "humidifier fever". This type of hypersensitivity pneumonitis was first described in 1959 by PESTALOZZI in the Swiss literature and subsequently by BANASZAK et al. in the Anglo-American. Here a chronic form of this disease which led to pulmonary fibrosis is described: A 37-year-old woman who works in a cheese shop presented with dyspnea which had been progressive over two years, weight loss, a diffuse reticular pattern radiographically and a severe restrictive defect in lung function tests. Open lung biopsy revealed chronic interstitial and alveolar inflammation with non-caseating granulomas and fibrotic changes. Circulating immune complexes and precipitins against the contaminated humidifier water and cheese mites were found, but no antibodies suggesting legionnaires' disease. Two out of five otherwise healthy employees of this cheese shop, where a new humidifying system had been installed 7 years earlier, also had precipitins against the contaminated water from the humidifier and the cheese mites. Despite ending of exposure and longterm steroid and immunosuppressive therapy, the signs and symptoms of pulmonary fibrosis persisted. Contrary to the acute disease, this chronic form is termed "humidifier lung". The importance is stressed of investigating the possibility of exposure to contaminated humidifiers or air conditioning units in all cases of newly detected pulmonary fibrosis.

Adult↗
PubMed1981

Herpesvirus papio DNA is similar in organization to Epstein-Barr virus DNA.

EcoRI, HindII, SalI, nd XbaI restriction endonuclease maps of herpesvirus papio (HVPapio) DNA were derived by determining the fragment sizes and the linkage relationships between fragments generated by the different enzymes. The data indicate that HVPapio DNA has a single molecular arrangement which is similar to that of Epstein-Barr virus DNA. The size of the DNA was 110 X 10(6) to 114 X 10(6) daltons. Restriction fragments from both ends varied in the number of repeats of a 4 X 10(5)-dalton sequence, TR, and hybridized to each other. This suggests that there is an identical repeating unit, TR, at both ends of the DNA. There were usually six tandem repetitions (range, 1 to 11) of a 2 X 10(6)-dalton sequence, IR, within the DNA. IR separated the DNA into two domains of largely unique sequence complexity, a 9 X 10(6)-dalton segment, Us, and an 88 X 10(6)-dalton segment, UL. There was homology between DNA fragments which mapped at 25 X 10(6) to 29 X 10(6) to 91 X 10(6) to 95 X 10(6) daltons in UL.

Animals↗
PubMed1980

Characterization of lymphoma-derived cell lines: comparison of cell lines positive and negative for Epstein-Barr virus nuclear antigen. I. Physical, cytogenetic, and growth characteristics.

Sixteen lymphoid cell lines were derived from patients with undifferentiated lymphoma of Burkitt's or non-Burkitt's type. They were obtained directly from tumor biopsies, from serous effusions, or from bone marrow. In 10 of the cell lines, the Epstein-Barr virus (EBV) nuclear antigen (EBNA) was undetectable; the remaining 6 lines were EBNA-positive (EB-pos). Of the 16 lines, 15 were aneuploid, with detectable chromosome "14q+ markers (11 had +8;14 translocations). These 15 lines, which included the EBNA-negative (EB-neg) lines, were believed to be of tumor cell origin. The remaining line consisted predominantly of diploid cells derived from normal lymphocytes, but some cells of tumor origin were present. Four EB-pos cell lines derived from EB-neg tumors had an aneuploid karyotype consistent with an origin from tumor cells (including no.8;14 translocation in two), which suggested that either tumor cells were infected with EBV in vitro or a tiny fraction of EB-pos tumor cells (or potential tumor cells) present in vivo gave rise to the predominant cell of the line. EB-neg B-cell lines and EB-pos cell lines established from undifferentiated lymphomas differed greatly. EB-neg lines had consistently smaller electronic mean cell volumes and narrow-angle light scatter than did EB-pos lines. This finding correlated with a lower nuclear:cytoplasmic ratio in EB-pos lines. EB-neg lines also had higher saturation cell densities than did EB-pos lines under standard culture conditions. The data indicate either that EBV influences the morphologic and physiologic characteristics of lymphoid cell lines or that EB-neg B-cell lines and EB-pos cell lines are derived ultimately from different lymphocyte subpopulations or that both may apply.

Antigens, Viral↗
PubMed1977

Biologic and antigenic characteristics of Epstein-Barr virus-related Herpesviruses of chimpanzees and baboons.

Leukocyte-transforming agents were isolated in baboon leukocytes inoculated with oral excretions from immunosuppressed chimpanzees. The transformed lymphoblasts had B cell surface markers and harbored herpes-type virus particles; 5-10% of the cells contained cytoplasmic antigens reactive with Epstein-Barr virus (EBV)-antibody-positive chimpanzee, human and baboon sera. These sera also neutralized the transforming activity of the chimpanzee virus. Long-term lymphoid cell lines were established from circulating lymphocytes of normal baboons: two from Papio cynocephalus and three from P. hamadryas. The cells had B cell surface markers, contained herpes-type virus particles and produced virus with leukocyte-transforming activity. No virus-associated nuclear antigen was detectable with reference baboon and chimpanzee sera; however, the cells reacted with selected human sera containing antibodies to EBV nuclear antigen (EBNA). Absorption experiments confirmed the specificity of this reaction. Baboon lymphoblasts produced baboon virus-associated soluble complement-fixing (CF/S) antigen. Baboon sera had CF antibodies to viral (CF/V) antigen derived from EBV but failed to react with EBV-associated CF/S antigen. Chimpanzee and baboon herpesviruses had similar in vitro host cell ranges but were different from those of EBV. Inoculation of baboons, rhesus monkeys and cottontop marmosets failed to produce detectable illness or palpable tumors.

Animals↗
PubMed1977

Productive Epstein-Barr viral infection of the human lymphoblastoid cell line 6410 with release of early antigen inducing and transforming virus.

The human lymphoblastoid cell line 6410 was superinfected with P3HR-1 derived Epstein-Barr virus. Subsequent to the first cycle of infection, characterized by early (EA) and virus capsid (VCA) antigen synthesis, the culture, designated 6410-EBV, continued to synthesize VCA. Further immunofluorescence and electron microscopic examination over 18-24 months showed the 6410-EBV culture to be productively infected with EBV. Virus was recovered, in quantity, from the culture fluids and assayed for ability to induce EA synthesis in Raji cells and to transform human umbilical cord lymphocytes. The virus was found to possess both properties, in contrast to P3HR-1 virus which only induces EA. HLA and karyologic analyses of P3HR-1, 6410 and 6410-EBV cultures showed relatedness of 6410-EBV to 6410 cells and dissimilarity to P3HR-1. The biologic activity data coupled with the cytologic analyses confirm a productive infection of the target cells. The reason for differences in biologic activity between the infecting (P3HR-1) and progeny virus is unresolved. It may be speculated that the endogenous EBV genome of 6410 cells was activated and gave rise to a different strain of EBV or to a mixed progeny-parent population as a result of dual infection. Alternatively, the parent strain of virus may have been modfied as a result of interaction with the new host cell.

Antigens, Viral↗
PubMed1977

Epstein-Barr virus and human malignancy.

The association of the Epstein-Barr virus and two human malignancies, Burkitt's lumphoma and nasopharyngeal carcinoma, is reviewed. Seroepidemiologic, virologic, and immunologic evidence is summarized, and several hypotheses regarding a possible etiologic role for the Epstein-Barr virus in these tumors are presented. With our current state of knowledge we cannot conclude that the Ipstein-Barr virus is oncogenic in man, nor can we yet ascertain the biological and clinical significance of its association with Burkitt's lymphoma and nasopharyngeal carcinoma.

Antibodies, Viral↗
PubMed1976

Comparative studies of Epstein-Barr virus strains from Ghana and the United States.

A high incidence of oropharyngeal excretion of Epstein-Barr virus (EBV) has been observed in African children with Burkitt's lymphoma (BL) (48%) and matched controls (45%). This compares with an incidence of 77% in American patients with infectious mononucleosis (IM) and 13% in age-matched controls. Cross-neutralization tests between EBV strains derived from BL and IM patients and their sera failed to detect differences in the major neutralizing antigenic components. Cord-blood lymphocytes transformed by American EBV expressed only early viral functions (EBV nuclear and soluble complement-fixing antigens) and produced no detectable transforming activity. By contrast, cord-blood lymphocytes transformed by African EBV strains contained 0.2-0.3% of cells with EBV capsid and early antigen and produced EBV with transforming activity. These cells contained twice as many copies of EBV homologous DNA as the cells transformed by American EBV strains.

Adolescent↗
PubMed1976

Leukocyte transforming agent (Epstein-Barr virus) in newborn infants and older individuals.

The lymphocyte transforming agent, associated with Epstein-Barr virus, was sought in the oropharynx and other clinical sites of 443 individuals in the following groups: premature and term neonates; infants with congenital malformations or with suspected TORCH syndrome; children with various illnesses; pregnant and postpartum women; healthy adults; and patients with infectious mononucleosis. Evidence of intrauterine infection was found in one newborn infant and LTA was demonstrated in a 16-day-old infant who developed transient hepatosplenomegaly. LTA was not detected in 96 other newborn infants and 57 infants with various anomalies or illnesses; nor was it found in the cervix of 125 pregnant or postpartum women. LTA was demonstrated in varying frequency in ill children, healthy adults, and those with infectious mononucleosis. It is suggested that the clinicoepidemiologic patterns of EBV infection in newborn infants and children will best be established by prospective studies.

Adolescent↗