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Biomedical subjects

G Klein

Publications and source records attributed to G Klein.

At least 1,099 records · Page 61Linked to original sources
PubMed1977

Antibodies against cytomegalovirus-induced early antigens (CMV-EA) in immunosuppressed renal-allograft recipients.

Antibodies against cytomegalovirus-specific early antigens (CMV-EA) were followed in sera, obtained from fifteen immunosuppressed renal-allograft recipients. Eight patients (sixty-two sera) showed seroconversion 47--137 days post-transplantation. Five patients (forty sera) with CMV antibodies at the moment of renal implantation all showed CMV-EA antibody rises. Two patients remained seronegative until 4 years after transplantation. Thus, in immunosuppressed patients, antibodies against CMV-EA remained a high titres during many years (4--8 years) after transplantation as distinct from the apparently transient nature in acutely infected previously healthy adults with CMV mononucleosis or post-perfusion syndrome. These results support the view that CMV-EA antibodies reflect an active viral proliferation in the host.

Adolescent↗
PubMed1977

Histochemical studies on the EBV-determined nuclear antigen (EBNA).

The EBV-determined nuclear antigen (EBNA) was studied with regard to several histochemical properties. Proteolytic enzymes destroyed EBNA staining. RNAse DNAse and hyaluronidase had no effect on the number of EBNA positive cells. Intensive treatment with DNAse weakened the chromosomal fluorescence of EBNA, whereas the staining of interphase nuclei was relatively enzyme resistant. When EBV-associated soluble complement-fixing antigen of Raji cells (CFA-R) was added to methanolacetic acid-fixed chicken red blood cells, brilliant and specific EBNA staining was obtained by anti-complement fluorescence (ACIF) with anti-EBNA positive sera. DNAse treatment abolished the ability of the nuclei to bind the antigen (CFA-R), whereas DNAse treatment following CFA-R antigen binding had no effect on the ACIF staining. EBNA was relatively heat stable. Somewhat weakened, but still fully positive EBNA reaction was obtained after 56 degrees C heating for 30 minutes in BSS. Periodate destroyed the EBNA reaction. Formaldehyde also abolished the staining, whereas methanol, acetone, methanol-acetone and methanol-hexyleneglycol-water preserved the staining relatively well.

Antigens, Viral↗
PubMed1977

Blastogenic response of purified human T-lymphocyte populations to Epstein-Barr virus (EBV).

The blastogenic response of T-cell populations to infectious EBV (B95-8 strain) was studied. The addition of virus increased the [3H]thymidine uptake of unfractionated lymphocytes from seropositive and seronegative subjects, and from cord blood, but not from patients with infectious mononucleosis. The same amount of virus evoked a small response in purified T cells from seropositive donors, but not in T cells from the other sources. The addition of autologous B lymphocytes with EBV adsorbed on their surfaces caused a more significant blastogenic response, which was even more pronounced in the presence of mercaptoethanol.

B-Lymphocytes↗
PubMed1977

Time sequence of direct vascular and inotropic effects following intravenous administration of digoxin in normal man.

The effects of a bolus injection of digoxin upon hemodynamics and left ventricular function were studied in 5 normal volunteers using cardiac ultrasound, ECG, carotid pulse pressure, and arterial blood pressure recording. Whereas the injection was followed by an immediate rise of the systemic vascular resistance, the inotropic action upon the myocardium followed with a delay of 10 to 30 minutes after injection.

Adult↗
PubMed1976

Inducibility of the Epstein-Barr virus (EBV) cycle and surface marker properties of EBV-negative lymphoma lines and their in vitro EBV-converted sublines.

Two EBV-negative lymphoma lines of human B-cell origin, BJAB and Ramos, were compared with altogether six of their in vitro EBV-converted, EBNA- and EBV-DNA-carrying sublines (four of Ramos and two of BJAB derivation). All converted lines closely resembled the parental line with regard to karyotype and HL-A and B antigen typing. Induction of EBV antigens (EA and VCA) by P3HR-1 virus superinfection was either similar in the converted and the negative lines, or somewhat increased in certain converted lines. These findings argue against a simple, virally determined repressor model and emphasize the role or cellular controls in restricting the EBV cycle in virus-carrying B-lymphocyte lines of human origin. IUdR inducibility varied in the different converted lines. There was a possible relationship between average number of EBV-genome equivalents per cell and inducibility. Converted sublines did not differ from the original negative lines with regard to surface immunoglobulin and Fc receptors. There was a dramatic increase in complement-consuming ability, however, following EBV conversion. Among the EBV-positive lines, there was a linear relationship between complement-consuming and EBV-receptor activity, the latter measured by a quantitative absorption test.

Antigens, Viral↗
PubMed1976

Circulating immune complexes in sera of patients with Burkett's lymphoma and nasopharyngeal carcinoma.

Sera of individuals with Burkitt's lymphoma and nasopharyngeal carcinoma, tested by consumption of hemolytic complement, were found by comparison with healthy individuals to have significantly increased levels of circulating immune complexes. The identity of the immune complexes was established by sucrose density gradient ultracentrifugation, which showed them to sediment between 10 and 19S. As they were adsorbable by rheumatoid factor--Sepharose 4B conjugates, it appeared that these complexes were composed of IgG. The complexes were retained by Concanavalin A--Sepharose columns and eluted by alpha methyl-D-mannoside, suggesting by analogy with model complexes that the antigens might be glycoproteins.

Adsorption↗
PubMed1976

Serologically detectable specific and cross-reactive antigens on the membrane of a polyoma virus-induced murine tumor.

With the aid of an assay measuring complement-dependent cytotoxocity mediated by syngeneic antibodies, we performed a serological analysis of surface antigens of a polyoma-virus-induced murine tumor (SEYF-a). In vivo propagated SEYF-a ascites tumor cells expressed a specific membrane antigen in addition to various other cross-reacting antigens. Among these we could identify at least four separate specificities. Two of these were present on MuLV-induced lymphoma cells, the first on Moloney-virus-induced YAC cells and the second on Gross-virus-induced GHA cells. The third cross-reacting antigen was detected on EL-4 cells. At least one additional specificity was present on two methylcholantthrene-induced murine sarcomas. Normal syngeneic lymphoid cells were insensitive to cytotoxicity mediated by the anti-tumor antisera. Quantitative and perhaps also qualitative differences between that antigenic expression of in vivo propagated on cultured SEYF-a cells were indicated. These studies show that hyperimmune sera produced in syngeneic mice against transplanted tumors may contain a considerable number of antibody specificities, only some of which are specific for the tumor. Furthermore, the results also suggest that polyoma-virus-induced tumors may possess individually distinct antigenic specificities, over and above the known cross-reacting TSTA or TSSA type antigen.

Animals↗
PubMed1976

Surface markers on human B and T-lymphocytes. IX. Two-color immunofluorescence studies on the association between ebv receptors and complement receptors on the surface of lymphoid cell lines.

Receptors for the third component of complement (C3) were demonstrated on the surface of established human lymphoid cell lines by a membrane fluorescence test with FITC- or TRITC-conjugated antibodies against human C3. Two-color fluorescence staining of EBV receptors and C3 receptors showed complete overlapping of green and red fluorescence. Capping of the EBV receptor induced co-capping of the C3 receptor and vice versa. There was neither overlapping nor co-capping when EBV or C3 receptors were examined in relation to Fc receptors, surface IgM or beta2 microglobulin. The kinetic pattern of EBV receptor capping was identical with the pattern of C3 receptor capping but differed from the pattern of IgM capping. These results suggest a close association between EBV and C3 receptors on the human B-lymphocyte.

B-Lymphocytes↗
PubMed1976

Detection of Epstein-Barr virus DNA in American Burkitt's lymphoma.

Twenty American patients with Burkitt's lymphoma (BL) were studied serologically and biochemically to detect an association with Epstein-Barr virus (EBV). A wide range of antibody reactivities was encountered. Five patients had serological profiles similar to those of African patients with BL: one and possibly two of these patients harbored EBV-DNA in their tumors. Fifteen patients had low or absent antibody to EBV: tumors from 10 of these patients lacked evidence of EBV-DNA. An unexplained association between elevated antibody (greater than or equal to 1:80) to EBV virus capsid antigen (VCA) and a favorable prognosis was noted in this series; this prognostic observation requires further substantiation. Thus, it appears that EBV-associated BL is inversely proportional to tumor endemicity. An etiological role for EBV in BL remains speculative.

Adolescent↗
PubMed1976

Somatic cell hybrids between human lymphoma lines. II. Spontaneous and induced patterns of the Epstein-Barr virus (EBV) cycle.

The regulation of spontaneous, IUDR-induced and P3HR-1 virus-induced EA and VCA production patterns was studied in two new somatic hybrids between human lymphoma lines. The hybrid 8A was derived from the crossing of the non-producer Raji with the spontaneous producer Daudi line. The second hybrid, 83, was produced by the fusion of Raji with the EBV-genome-negative B-lymphoma line, BJAB. The studies suggest the following EBV regulation patterns: (1) the spontaneous production of EA and VCA appears to be regulated by controls that differ from the regulators of P3HR-1 virus-induced or IUDR-induced EA synthesis. While spontaneous producer status was dominant over non-producer status, the level of EA inducibility was set by one of the parental cells, Raji ATG, and could either raise (in the previously studied Raji/Namalwa hybrid, cf Nyormoi et al. 1973) or depress (in Raji/Daudi) the level of relative EA inducibility found in the partner cell. (2) Although EA production is a prerequisite for VCA synthesis, the latter is under its own restriction mechanisms, quite independent of those that regulate the level of EA synthesis. (3) Inducibility of EA synthesis by P3HR-1 virus and by IUDR appear to be under the influence of at least partially identical controls. (4) EBV-negative lymphoma cells, exemplified by BJAB, may exert a "complementation" effect on the EA inducibility of their EBV-positive fusion partner, in spite of their own restrictivity against virus-induced EA synthesis. In more general terms, it is obvious that the EBV cycle is under the influence of multiple regulatory mechanisms in the human lymphoid cell. Depending on the parental cell and viral genomes that are allowed to interact, somatic cell hybrids may display a variety of patterns. At this time, cell hybridization is one of the few pathways that permit an approach to this complex and completely unknown world.

Antigens, Viral↗
PubMed1976

Isobongkrekic acid, a new inhibitor of mitochondrial ADP-ATP transport: radioactive labeling and chemical and biological properties.

An isomer of bongkrekic acid, designated as isobongkrekic acid, has been isolated from ethereal extracts of Pseudomonas cocovenenans grown on defatted coconut. Isobongkrekic acid was also obtained by alkaline treatment of bongkrekic acid. Isobongkrekic acid possesses the same ultraviolet spectrum and the same molecular weight as bongkrekic acid; it has a similar infrared spectrum but not the same nuclear magnetic resonance (NMR) spectrum. The differences in NMR data were interpreted to mean that isobongkrekic acid differs from bongkrekic acid by the configuration of the dicarboxylic end; whereas the two carboxylic groups of the dicarboxylic end have the trans configuration in bongkrekic acid, they have the cis configuration in isobongkrekic acid. Differences between bongkrekic and isobongkrekic acids are lost after catalytic hydrogenation of the molecules. Isobongkrekic acid, like bongkrekic acid, is an uncompetitive inhibitor of ADP transport in mitochondria, provided the mitochondria are preincubated in the presence of the inhibitor and a minute concentration of ADP. The inhibitory and binding efficiency of isobongkrekic acid is considerably increased below pH 7. The number of high affinity sites for [3H] isobongkrekic acid is 0.13 to 0.20 nmol/mg protein in rat liver mitochondria and about 1 nmol/mg protein in rat heart mitochondria, i.e., similar to the number of high affinity sites for [3H] bongkrekic acid. Isobongkrekic and bongkrekic acids compete for the same site, but the affinity of isobongkrekic acid for mitochondria is one-half to one-fourth that of bongkrekic acid.

Adenosine Diphosphate↗
PubMed1976

Concanavalin A receptors on the surface membrane of lymphocytes from patients with African Burkitt's lymphoma and lymphoma cell lines.

Lymphocytes isolated from the peripheral blood and from tumor tissues of patients with African Burkitt's lymphoma have been studied for cap formation and agglutinability by Concanavalin A (Con A). Peripheral blood from healthy adult persons served as a normal control and blood from patients with carcinoma served as a non-lymphoma control. These studies included 29 patients with Burkitt's lymphoma, 93 with carcinoma, and 105 healthy adult persons, as well as tumor tissues from 13 patients with Burkitt's lymphoma. The great majority of the carcinomas were from the face and neck regions. Lymphocytes from the blood of the majority of patients with Burkitt's lymphoma, as well as those from tumor tissues, exhibited a reduced cap-forming ability (2-6%) and increased Con-A-induced agglutinability compared to lymphocytes from healthy normal donors and from patients with carcinoma, although some of the lymphocytes from patients with carcinoma had a somewhat lower range of cap formation than the lymphocytes from healthy donors. No difference was observed in the interaction with Con A of lymphocytes from the different types of carcinoma studied. Eight lymphoid cell lines were established in our laboratory from the tumor tissues of patients with Burkitt's lymphoma. The cap-forming ability and agglutinability by Con A of these lines was examined and compared to those of the "classical" lymphoma lines: Raji, Daudi and P3HR1. All cell lines exhibited an increased Con-A-induced agglutinability and a reduced cap-forming ability compared to normal lymphocytes, except for P3HR1 cells which exhibited a cap-forming ability of 15-20%. These findings are discussed in relation to the association of the lymphocytes with malignancy and as a possible aid in the differential diagnosis between malignant lymphomas and other diseases.

Agglutination↗
PubMed1976

Tumorigenicity of Epstein-Barr virus (EBV)-transformed lymphoid line cells in autologous squirrel monkeys.

Eight squirrel monkeys (Saimiri sciureus) challenged with EBV or EBV-transformed SLCL were naturally or experimentally infected with Plasmodium knowlesi or Pl. brasilianum. Most of the animals had been splenectomized and unilaterally nephrectomized. Three of these monkeys received one dose of 6 to 12 X 10(8) autologous SLCL. These lines were derived from saimiri lymphoid cells permanently transformed by B-EBV in vitro. All three animals developed multiple undifferentiated malignant lymphomas and died 8 to 10 days post inoculation. Necropsy tumor specimens were EBNA-positive and contained 7 to 21 EBV genome equivalents per cell. EBNA- and EA-positive SLCL were established in vitro from four tumor explants of two monkeys. These results demonstrate that in vitro EBV-transformed SLCL are able to cause tumor formation in autologous squirrel monkeys. Five monkeys received high transforming doses of B-EBV or S-EBV, derived from one of the tumorigenic SLCL. None of the animals developed any sign of tumor formation during an observation period of up to 130 days. Three of these monkeys showed no detectable EBV-related seroconversion while the sera of two monkeys had become anti-EBNA-positive when tested at days 28 and 130 respectively post inoculation. Two additional monkeys received neither EBV nor SLCL. They showed no clinical evidence of tumor development or spontaneous seroconversion over a period of more than 1 year.

Animals↗