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H Bayer

Publications and source records attributed to H Bayer.

At least 37 records · Page 2Linked to original sources
PubMed1987

Synthetic vaccines against Friend murine leukaemia virus-induced erythroleukaemia: in vivo and in vitro studies with synthetic oligopeptides and sequence-specific antisera.

Biological activities of antisera against synthetic oligopeptides were examined. The peptide antisera were directed against amino acids 6 to 12 (pep1), 124 to 131 (pep2), 256 to 262 (pep3), 283 to 290 (pep4) and 434 to 441 (pep5) of the viral envelope glycoprotein (gp70). Peptide-specific antisera did not neutralize viral infectivity. However, antibodies to pep4 and pep5, which bound to the hydrophobic part of gp70, mediated the complement-dependent lysis of Friend murine leukaemia virus (FLV)-infected cells. STU mice were immunized against FLV-induced erythroleukaemia with synthetic oligopeptides. Vaccines containing only one of these peptides (single-peptide vaccines) as well as multi-peptide vaccines containing pep1, -4, -5 or pep1, -2, -3, -4, -5 were used. Whereas the immunizations with single-peptide vaccines did not protect the immunized mice from FLV-induced erythroleukaemia, multi-peptide vaccines enhanced the survival rate and incubation period after FLV challenge. These results revealed that immunological reactions distinct from neutralizing antibodies can be evoked by immunization with synthetic peptides and can confer limited protection against FLV-induced erythroleukaemia.

Amino Acid Sequence↗
PubMed1986

Antibodies to HTLV-I in Nigerian blood-donors, their relatives and patients with leukaemias, lymphomas and other diseases.

Antibodies to HTLV-I have been detected in sera from 15 (2.0%) of 736 adult blood-donors in Nigeria, in 4 (20.0%) of 20 patients with chronic lymphatic leukaemia, 3 (10.0%) of 30 with non-Hodgkin's lymphoma, one of 12 with Burkitt's lymphoma and one of 7 with acute lymphoblastic leukaemia. The frequency of positivity was higher (3.6%) in the blood-donors from the guinea and wooded savanna of northern Nigeria than in those from the rain-forest and mangrove swamps of southern Nigeria (1.8% in Lagos and 0.7% in Calabar). Two of the 3 seropositive patients with lymphoma had clinical presentation and courses similar to those of Japanese and Caribbean patients with adult T-cell leukaemia/lymphoma.

Antibodies, Viral↗
PubMed1986

Quantification of infection and neutralization of murine leukaemia virus by a microtitre enzyme-linked immunosorbent assay.

We have developed an enzyme-linked immunosorbent assay for murine leukaemia virus using methanol-fixed cells as antigen. Specific antisera clearly recognized viral antigens within cells adherent to the microtitre plates. This test was used to quantify infection, to monitor virus multiplication and to demonstrate virus neutralization by antisera. The ELISA was as sensitive as, and faster and easier to perform than, the XC plaque assay and could even quantify large amounts of virus. It can easily be adapted for assaying other viruses.

Animals↗
PubMed1986

Immunoprevention of Friend leukaemia virus-induced erythroleukaemia by vaccination with aggregated gp70.

Vaccines prepared from Friend leukaemia virus envelope and core polypeptides were compared for their efficiency in preventing erythroleukaemia in mice. High doses (100 micrograms) of gp85, the micellar complex of the envelope polypeptides gp70 and p15E, completely protected STU mice. The same dose of purified gp70 still protected about 80% of the animals, while p15E did not affect the cumulative mortality. The internal viral polypeptide p30 was ineffective. Serological examination indicated that immunity against death from leukaemia was mediated by specific antibodies. These leukaemia-preventing antibodies were predominantly induced by immunization with the gp70 env gene product, since p15E showed only minor protection. Glycoprotein gp70, however, was more effective when given as the gp85 micellar complex. An even more potent vaccine was obtained when gp70 was coupled to keyhole limpet haemocyanin (KLH) by glutaraldehyde. Ten micrograms gp70 coupled to KLH was enough to save more than 90% of Friend leukaemia virus-infected mice from erythroleukaemia. KLH may also be a suitable experimental carrier for subunits of gp70 or synthetic oligopeptides for viral vaccines.

Animals↗
PubMed1985

Lymphadenopathy and antibodies to HTLV-III in homosexual men. Clinical, laboratory and epidemiological features.

The study provides information on the epidemiology of HTLV-III infection and the lymphadenopathy syndrome (LAP) in 374 German homosexual men. Sexual contacts in the USA and rectal enemas before receptive anal intercourse are the main risk factors associated with virus transmission. HTLV-III seropositivity is significantly correlated with LAP. Prominent clinical signs are infrequent. Immunological and haematological abnormalities are prevalent, and the retrovirus infection is frequently associated with serological markers of other viruses (hepatitis B, herpes group viruses). Lymphadenopathy as a manifestation of HTLV-III infection is discussed within the context of AIDS-related disorders.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Seroepidemiology of HTLV-III (LAV) in the Federal Republic of Germany.

In 1984 10,281 sera were collected in the FRG and examined for antibodies to HTLV-III (LAV) with an enzyme-linked immunosorbent assay and confirmative tests. Of the German AIDS patients 81% have antibodies. Individuals belonging to AIDS risk groups, homosexuals, haemophiliacs and i.v. drug abusers, have antibody frequencies between 25%-72%. The detection of HTLV-III antibodies in blood donors indicates that the virus is being transmitted by blood transfusions.

Acquired Immunodeficiency Syndrome↗
PubMed1985

A glycopolypeptide (gp 100) is the main antigen detected by HTLV-III antisera.

Sera from homosexuals and hemophiliacs in Germany were examined for antibodies to human T-lymphotropic retrovirus type III (HTLV-III) by an enzyme-linked immunosorbent assay (ELISA) against purified virus. ELISA positive sera were used to search by immunoprecipitation for HTLV-III related antigens in a persistently infected human T-cell line. A glycopolypeptide with a mol. wt. of 100 000 was regularly recognized by all positive sera. In analogy to glycosylation and high antigenicity of envelope polypeptides of other mammalian retroviruses, gp 100 seemed to be related to the env gen. Two polypeptides with mol. wts. of 24 000 and 22 000 probably representing viral core polypeptides were additionally detected by sera with high ELISA titers.

Antibodies, Viral↗
PubMed1985

Antibodies to adult T-cell leukemia virus (ATLV/HTLV-I) in AIDS patients and people at risk of AIDS in Germany.

A total of 2048 serum samples from Germany were examined for antibodies to adult T-cell leukemia virus (ATLV) structural polypeptides with an enzyme-linked immuno sorbent assay (ELISA) and confirmative immuno precipitation. The origin of the sera samples was: 850 samples taken for virological or protozoal diagnosis; 626 samples from male homosexuals, about 20% of whom had lymphadenopathy syndrome; 164 from hemophiliacs; 184 were from multiple transfused, mostly dialysis patients; 9 from intravenous drug abusers; 182 from suspected cases of acquired immuno deficiency syndrome (AIDS) and 33 from AIDS-patients. In none of these sera did we detect antibodies to ATLV, except in the serum of one patient who had been on hemodialysis for over 11 years. Obviously infection with ATLV or a serologically related agent is very rare in our country and an association with AIDS could not be observed.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Structural and immunological characterization of Friend murine leukaemia virus glycopolypeptide using synthetic oligopeptides.

Using terminal position, hydrophilicity, predicted reverse turns and type specificity as criteria, five oligopeptides were selected for synthesis from the amino acid sequence of the envelope glycopolypeptide gp70 of Friend murine leukaemia virus. These peptides corresponded to the amino acids 6-12 (pep1), 124-131 (pep2), 256-262 (pep3), 283-290 (pep4) and 434-441 (pep5). After coupling to carriers, bovine serum albumin or keyhole limpet hemocyanin, antisera were prepared in rabbits. All of the five oligopeptides were immunogenic and pep1, pep2, pep4 and pep5 were able to elicit antibodies to the native glycopolypeptide. These sequence-specific antisera distinguished between glycoproteins of different leukaemia viruses. At least three of the selected peptides, the type-specific oligopeptides pep3, pep4 and pep5, were found to be natural epitopes of gp70.

Amino Acid Sequence↗
PubMed1984

Antibodies to ATLV/HTLV-1 in Africa.

Almost 4000 sera from seven African states were examined for antibodies to ATLV/HTLV-1. Between 1% and 8% of healthy people from sub-Saharan Africa have such antibodies. The highest frequency was observed in Gabon. There were considerable variations between villages. The percentage of seropositives and the mean titre increased with age. Our findings suggest that the African continent is the largest endemic area for ATLV.

Adolescent↗
PubMed1984

Structural and epidemiological features of primate lymphotropic retroviruses.

Primate lymphotropic retroviruses (PLRV) have been isolated from man and various species of Old World monkeys. The human isolates adult T-cell leukemia virus (ATLV) or human T-cell leukemia virus (HTLV-I) are endemic among Japanese in the south-west of the country as well as Africans in both Africa and America. In these populations ATL and its lymphoma variant are also endemic and all these patients harbor the virus and have serum antibodies to viral env gene polypeptides gp68, gp46, p21 as well as core polypeptides p24, p19, and p15. ATLV and respective viral antibodies are very rare outside the endemic areas. Retroviruses structurally and serologically related have been found in various species of Old World monkeys especially in macaques. The human lymphadenopathy associated virus (LAV) later also known as HTLV-III most probably is the etiological agent of the acquired immunodeficiency syndrome (AIDS) in man and related syndromes. LAV/HTLV-III is highly endemic in certain parts of the population of America and Europe and apparently also in Africa. Human antisera react with viral envelope related gp120, gp100, gp46, and core related p24, p21, and p15 polypeptides. In our assays LAV/HTLV-III does not crossreact serologically with ATLV/HTLV-I and its major structural polypeptides may be related distantly to primate lymphotropic retroviruses (PLRVs) isolated from macaques but not to ATLV/HTLV-I.

Acquired Immunodeficiency Syndrome↗
PubMed1984

[Pregnancies caused by in vitro fertilization in cycles, stimulated with human hypophyseal gonadotropin and chorionic gonadotropin].

In a program of in vitro fertilization, laparoscopies for oocyte aspiration were performed on 35 patients receiving human pituitary gonadotropin (hPG) and human chorionic gonadotropin (hCG). Of the 122 preovulatory oocytes which were recovered from these patients, 44 (36%) were fertilized and cleaved, and were transferred. 144 immature oocytes were collected, and attempts were made to mature these in vitro. 40 oocytes (28%) could be fertilized and cleaved, and were transferred. Eight pregnancies resulted from 32 embryo transfers (25%), and 22,9% from laparoscopies, respectively. Of the eight pregnancies, there were three preclinical abortions and two clinical abortions, and three patients are well along in the pregnancy. Among the three patients there is one twin pregnancy.

Adult↗
PubMed1983

Interactions of bisquaternary pyridine salts (H-oximes) with cholinergic receptors.

Certain recently developed antidotes of the bispyridinium type, commonly called "H-oximes" (HGG 12, 21, 42, 52, 65, 70, 89, and HGG 90) have been investigated as to their effects on muscarinic and nicotinic acetylcholine receptors. These compounds clearly discriminate between these two types of receptors being more potent inhibitors of the muscarinic receptor with inhibitory constants in the micromole range. (The corresponding values for the nicotinic receptor are in the range of 0.1 mM.) However, the inhibitory potency in the binding assay does not correlate with the ED50 values obtained against soman in mice. The site of antidotal action therefore appears not to be the nicotinic acetylcholine receptor. Binding to the muscarinic receptors may partially contribute to the effects against soman in vivo.

Acetylcholine↗
PubMed1983

Active immunization with feline leukemia virus envelope glycoprotein suppresses growth of virus-induced feline sarcoma.

The efficiency was examined of immunization with feline leukemia virus glycoprotein complexes (gp85 rosettes) to protect cats against tumors induced by feline sarcoma virus (FeSV). The glycoprotein was isolated from feline leukemia virus (FeLV). Young cats were vaccinated with the purified viral glycoprotein and challenged with FeSV (FeLV). FeLV gp85 antibody levels were measured by enzyme-linked immunosorbent assay and tumor volumes were determined. In immunized animals tumor development was reduced. Gp85 antibody levels before challenge were correlated inversely with tumor size (r2 = 0.79). This method appears to be suitable for fast and efficient testing of future FeLV vaccines.

Animals↗