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Biomedical subjects

A Burny

Publications and source records attributed to A Burny.

At least 235 records · Page 13Linked to original sources
PubMed1984

The nucleotide sequence of the env gene and post-env region of bovine leukemia virus.

The env gene of a bovine leukemia virus (BLV) tumor-derived proviral DNA clone has been located by comparison of the translated DNA sequence with amino acid sequence data on purified gp60 and p30env (A. M. Schultz, T. D. Copeland, and S. Oroszlan (1984) Virology 135, 417-427). There is a continuous open reading frame from the N terminus of gp60 for 1446 nucleotides; gp60 is predicted to contain 268 amino acids and p30env, 214. The predicted p30env shows structural features typical of type C viral transmembrane proteins. It is also clearly related to that of the human T-cell leukemia virus (HTLV), as predicted from the DNA sequence of Seiki et al. (M. Seiki, S. Hattori, Y. Hirayama, and M. Yoshida (1983) Proc. Natl. Acad. Sci. USA 80, 3618-3622) The two proteins show 36% identities in their amino acid sequence, in an alignment requiring six gaps. More distant relatedness is also seen between BLV p30env and both murine leukemia virus p15E and Rous sarcoma virus gp36. The gp60s of BLV and HTLV are more distantly related than their p30envs, but their homology is nonetheless statistically significant. Between the presumptive terminator of the env gene and the beginning of the 3'-long terminal repeat is a region of 1817 base pairs of unknown function. Just as in the HTLV post-envelope sequence, there are at least two reading frames which are open for a significant fraction of this region. In neither the tumor-derived clone nor a clone from a virus-producing cell line, however, is there a continuous open reading frame throughout the region. Comparison of the BLV and HTLV sequences within the post-envelope region revealed a very limited but possibly significant similarity.

Amino Acid Sequence↗
PubMed1984

Biologically active epitopes of bovine leukemia virus glycoprotein gp51: their dependence on protein glycosylation and genetic variability.

A panel of monoclonal antibodies to the bovine leukemia virus envelope glycoprotein (BLV gp51) has previously demonstrated the association of the biological activities of the virus (infectivity, syncytia induction) with three out of eight epitopes of gp51. In BLV-infected cells, the unglycosylated homolog of the precursor to the BLV envelope glycoproteins (gPr72env) is a 47,000-MW polypeptide. Immunoprecipitation studies with monoclonal antibodies show that the neutralizing antibody-inducing sites, although present in gPr72env, are not conserved in the 47,000-MW unglycosylated homolog. Finally, it is demonstrated that the neutralizing antibody-inducing sites of gp51 are subject to antigenic variation among BLV isolates of the same or different geographical origins.

Animals↗
PubMed1984

Bovine leukemia virus (BLV)--a structural model based on chemical crosslinking studies.

Nearest neighbor relationships between lipid and protein as well as between high-molecular-weight viral RNA and protein were investigated in bovine leukemia virus (BLV) particles using chemical crosslinking reagents. Separation of dimethyl suberimidate (DMS) induced lipid-protein complexes by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the phosphoprotein pp 15 is linked to the lipid bilayer of the virus. By use of diepoxybutan (DEB) as crosslinking reagent p 12 and again pp 15 were found to be linked to the viral RNA. Based on these results and our previous data describing the spatial relationships of major structural proteins within BLV particles, a structural model of BLV is proposed.

Animals↗
PubMed1984

Experimental infection of sheep and goat with bovine leukemia virus: localization of proviral information on the target cells.

Bovine leukemia virus (BLV) proviral integration was studied in the DNA from circulating leucocytes or tumor cells of sheep and goats experimentally infected with BLV. Southern blot analysis of infected cell DNA for BLV proviral sequences indicate that: (1) the provirus may be found as unintegrated molecules in the circulating leucocytes of infected sheep; (2) the provirus is integrated at many sites in the genome of the leucocytes of infected goats and occasionally in infected sheep; (3) the provirus is present at only a few sites in the DNA of sheep or goat tumor cell clones. A second case of goat lymphosarcoma is also reported.

Animals↗
PubMed1984

Epitopes of bovine leukemia virus glycoprotein gp51 recognized by sera of infected cattle and sheep.

Sera of BLV-infected cattle and sheep are tested for their reactivity with different gp51 subregions by competition with radiolabeled monoclonal antibodies directed against 8 different gp51 epitopes. Sheep antisera are found to be very polyvalent, since they are able to displace the fixation of any of the mouse monoclonal antibodies to gp51. Bovine antisera do not display significant competition with monoclonal antibodies direct against 5 out of 8 gp51 epitopes. The bovine antibody response to gp51 is focused to a limited subregion of this molecule, bearing 3 epitopes (F, G and H) recognized by antibodies with virus-neutralizing activity. The differential reactivity of cattle and sheep antisera to BLV gp51 is discussed in relation to the pathology of BLV infection in these two species.

Animals↗
PubMed1984

Nucleotide sequence analysis of the long terminal repeat of integrated bovine leukemia provirus DNA and of adjacent viral and host sequences.

The nucleotide sequence of the 3' long terminal repeat and adjacent viral and host sequences was determined for a bovine leukemia provirus cloned from a bovine tumor. The long terminal repeat was found to comprise 535 nucleotides and to harbor at both ends an imperfect inverted repeat of 7 bases. Promoter-like sequences (Hogness box and CAT box), an mRNA capping site, and a core enhancer-related sequence were tentatively located. No kinship was detected between this bovine leukemia proviral fragment and other retroviral long terminal repeats, including that of human T-cell leukemia virus.

Animals↗
PubMed1984

Different bovine leukemia virus-induced tumors harbor the provirus in different chromosomes.

DNAs from 25 independent hamster X bovine somatic cell hybrids were submitted to the Southern blot analysis with probes made of unique cellular fragments adjacent to single-copy proviruses from three different bovine tumors. It appeared that these cellular sequences, and thus the respective proviruses, belonged to three different chromosomes in the three different tumors examined.

Animals↗
PubMed1984

Characterization of cellular sequences flanking an integrated bovine leukemia virus genome.

We cloned a 20.2-kilobase fragment, including the unique proviral integration site, from the tumor tissue DNA of a bovine leukemia virus-induced lymphoma (tumor 1351). This clone contained 5.5 kilobases of flanking sequences at either side of the full-length integrated viral genome. Hybridization analysis of both 3' and 5' cellular flanking regions provided no evidence for rearrangements at this locus in other tumors, RNA transcription from either flanking region, or homology to eight known onc genes.

Animals↗
PubMed1984

Ultrastructural demonstration of retrovirus antigens with immuno-gold staining in prodromal acquired immune deficiency syndrome.

The peripheral lymphocytes of a patient with prodromal acquired immune deficiency syndrome contained giant multivesicular bodies. These were specifically stained by immuno-gold labelled polyclonal antibodies against the major core protein p24 of bovine leukaemia virus and human T cell leukaemia virus I. Moreover, the patient's serum was positive for bovine leukaemia virus by the ELISA method.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Bovine leukemia virus, a distinguished member of the human T-lymphotropic virus family.

Bovine leukemia virus (BLV) has many structural and functional characteristics in common with the human T-lymphotropic viruses (HTLVs). The most striking feature of these retroviruses is the existence of a long open reading frame (LOR) located at the 3' side of the provirus between the right end of the 3' side of env gene and the left end of the long terminal repeat (LTR). It is believed that the LOR protein product is of critical importance in the induction process of the tumor phase of bovine leukemia. Prevention of BLV infection will be attempted by vaccination. To that aim, careful study of BLV envelope glycoprotein epitopes has shown that epitopes F, G, and H play a major role in biological activities of the virus. Their native structure depends upon glycosylation of the peptide backbone.

Animals↗
PubMed1984

[Laser endoscopic treatment of cysts of the larynx and laryngoceles].

Twelve patients (8 with appendicular laryngeal cysts and 4 with laryngoceles) were treated in the ENT Unit, Lille between 1980 and 1983. Therapy was by laser through endoscopic guidance, and consisted of resection of the ventricular band to allow marsupialization of the cyst or mixed laryngocele in the endolarynx. Treatment was effective in all cases with restoration of a normal larynx within 2 to 3 months, even in patients with external laryngoceles. This method is of particular interest in bilateral lesions.

Adult↗
PubMed1984

[Our experience with the pectoralis major musculocutaneous flap. Apropos of 57 cases].

One of the most important technical advances in cervicofacial plastic surgery over the last few years is undoubtedly the use of the musculocutaneous flap from pectoralis major. A review of its application in 57 cases showed the flap to be of excellent viability (5% total necrosis of flap), and to offer multiple possibilities during primary surgery or that following radiation. Indications and excision limits can be extended, particularly in buccopharyngeal surgery, providing and appreciable functional gain (particularly disappearance of pain), even though long-term carcinologic advantages are deceiving.

Adult↗
PubMed1984

Isolation and purification of bovine immunoglobulins: use of Sephacryl S-300 filtration avoids protein precipitation steps.

A simplified purification method for bovine IgG1, IgG2, IgM, IgA and S-IgA is presented. It takes advantage of Sephacryl S-300 gel filtration. When applied to this column, colostral whey can be separated into IgM, S-IgA and IgG rich fractions. Filtration of blood serum leads to IgM, IgA and IgG rich fractions. IgM, IgG1, IgG2, S-IgA and IgA are then further purified by anion exchange chromatography.

Acrylic Resins↗