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Biomedical subjects

V Daniel

Publications and source records attributed to V Daniel.

At least 109 records · Page 6Linked to original sources
PubMed1989

Carp growth hormone: molecular cloning and sequencing of cDNA.

cDNA clones of the fish Cyprinus carpio growth hormone (GH) mRNA have been isolated from a cDNA library prepared from carp pituitary gland poly(A)+RNA. The nucleotide sequence of one of the carp GH cDNA clones containing an insert of 1164 nucleotides (nt) was determined. The cDNA sequence was found to encode a polypeptide of 210 amino acids (aa) including a signal peptide of 22 aa and to contain 5' and 3' untranslated regions of the mRNA of 36 and 498 nt, respectively. The carp GH presents a 63% amino acid sequence homology with the salmon GH, has structural features common with other GH polypeptides of mammalian or avian origin and contains domains of conserved sequence near the N- and C-terminal regions. Southern blot hybridization of carp genomic DNA with GH cDNA probes shows the presence of at least two GH-coding sequences in the fish genome.

Amino Acid Sequence↗
PubMed1989

Autoantibodies against CD4- and CD8-positive T lymphocytes in HIV-infected hemophilia patients.

The presence of IgG, IgM, C3d, or gp120 on the surface of T lymphocytes was analyzed by flow cytometry in blood samples from 73 hemophilia patients and 56 healthy controls. IgG and IgM autoantibodies against CD4+ lymphocytes were found in HIV + patients but not in HIV-patients or healthy controls (p less than 0.001). IgM autoantibodies were more frequent than IgG autoantibodies. Autoantibody formation increased with disease progression. However, within the same disease risk category, patients with autoantibodies were not "more immunologically abnormal' than patients without autoantibodies. HIV + patients who possessed autoantibodies had similar CD4+ and CD8+ lymphocyte counts as HIV + patients without autoantibodies. There was no significant difference in the number of patients with abnormal CD4/CD8 ratios, serum neopterin levels, or in vitro responses to allogeneic stimulator cells or mitogens between autoantibody-positive or -negative patients of the same risk category. Our data suggest that autoantibodies against CD4+ lymphocytes may be helpful as indicators of disease progression, however, their immunopathogenetic role remains unclear.

AIDS-Related Complex↗
PubMed1989

Low concentrations of acid-soluble thiol (cysteine) in the blood plasma of HIV-1-infected patients.

Blood plasma samples from HIV-1-infected persons contain elevated glutamate concentrations up to 6-fold the normal level and relatively low concentrations of acid-soluble thiol (i.e. decreased cysteine concentrations). The intracellular glutathione concentration in peripheral blood-mononuclear cells (PBMC) and monocytes from HIV antibody-positive persons are also significantly decreased. Therapy with azidothymidine (AZT) causes a substantial recovery of the plasma thiol levels; but glutamate levels remain significantly elevated and intracellular glutathione levels remain low. Cell culture experiments with approximately physiological amino-acid concentrations revealed that variations of the extracellular cysteine concentration have a strong influence on the intracellular glutathione level and the rate of DNA synthesis [( 3H]thymidine incorporation) in T cell clones and human and murine lymphocyte preparations even in the presence of several-fold higher cystine and methionine concentrations. Cysteine cannot be replaced by a corresponding increase of the extracellular cystine or methionine concentration. These experiments suggest strongly that the low cysteine concentration in the plasma of HIV-infected persons may play a role in the pathogenetic mechanism of the acquired immunodeficiency syndrome.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Immunostimulants--therapeutic aspects].

A survey is given about the so far known mode of action and the therapeutic application of the following agents with immunostimulatory effects: Interleukin-2, Interferon-gamma, Tumor necrosis factor, Thymosin alpha 1, Thymopentin, Splenopentin, Thymulin, Thymostimulin, Muramyl dipeptide, Bestatin, Tuftsin and Levamisole. The treatment of patients suffering from immunodeficiency disorders and cancer with such agents seems to be possible in the near future.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1989

B lymphocyte response as an indicator of acute renal transplant rejection. I. Immunoglobulin-secreting cells in peripheral blood.

Monitoring of immunoglobulin-secreting cells in peripheral blood was performed in 88 renal transplant recipients using a reverse hemolytic plaque-forming cell assay. Comparison with other in vitro tests for rejection (plasma neopterin, CD4/CD8 ratio) demonstrated that the number of immunoglobulin-secreting cells in peripheral blood provides a highly sensitive rejection marker. Evidence of rejection was obtained 1.7 +/- 0.4 (mean +/- SEM) days before a rise in creatinine, with a significant PFC rise in 95% (73/77) of rejection episodes. The PFC response was not influenced by HLA matching, number of preoperative blood transfusions, acute tubular necrosis, or uremia. A significant PFC rise in the absence of an ongoing rejection episode occurred in the presence of bacterial or viral infections, in case of posttransplant surgical complications, and regularly during the early posttransplant period (days 4-9). However, even early posttransplant the PFC peak was significantly higher in patients with an ongoing rejection episode than in patients without rejection (P less than 0.001).

Antibody-Producing Cells↗
PubMed1989

B lymphocyte response as an indicator of acute renal transplant rejection. II. Pretransplant and posttransplant B cell responses of m mitogen and donor cell-stimulated cultures.

In a prospective study we investigated the association of kidney graft rejection with pre- and posttransplant B cell responses in vitro after stimulation with pokeweed mitogen, Staphylococcus aureus Cowan I (SAC I), or donor lymphocytes. B cell differentiation was assessed in a reverse hemolytic plaque assay. Elevated pretransplant PWM- or SAC I-stimulated B cell responses were found to define patients with a high incidence of rejection episodes in the first 30 days posttransplant (P less than 0.005 and P less than 0.05, respectively). Elevated pretransplant donor cell-stimulated B cell responses were associated with a high risk of irreversible rejection (P less than 0.005). A posttransplant rise in donor cell-stimulated B cell responses was associated with an increase risk of a subsequent rejection crisis (P less than 0.05). Our data suggest that patients at risk of early rejection may identified by pretransplant testing of B cell responses.

Antibody-Producing Cells↗
PubMed1989

Lymphocyte autoantibodies and alloantibodies in HIV-positive haemophilia patients.

Immune parameters were studied in 86 haemophilia patients (six with AIDS) and 87 healthy controls. We found lymphocytotoxic alloantibodies in HIV-positive (HIV+) sera which reacted preferentially with B lymphocytes but also with T lymphocytes, and which reacted more frequently at 4 degrees C than at 37 degrees C. The antibodies were not directed against HIV-induced structures on T lymphocytes and they were reactive with both CD4+ and CD8+ lymphocytes. In addition to cytotoxic alloantibodies, cytotoxic autoantibodies were detected which coated patient lymphocytes in vivo. Increased proportions of in vivo-antibody-coated-cells were found in 37 of 86 haemophilia patients. Antibody binding was labile so that the immunoglobulins were partially removed from the lymphocyte surface by washing. The autoreactive antibodies were of IgG and IgM type, fixed complement as demonstrated by increased anti-C3d+ cells in the patients' blood, and reacted with CD4+ as well as CD8+ lymphocytes. There was a statistically significant correlation of increased Ig+ cells with HIV infection, decreased CD4/CD8 ratios, increased serum neopterin levels, and abnormal in-vitro responses to pooled allogeneic stimulator cells or CD3 monoclonal antibody. Patients with increased Ig+ cells were lymphopenic, had decreased absolute counts of CD4+, CD25+, CD21+ and OKM5+ cells, and higher percentages of CD8+ and OKIa1+ cells in their blood than patients with normal levels of Ig+ cells. Our data suggest a role of autoreactive anti-lymphocyte antibodies in the pathogenesis of acquired immunodeficiency.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Nucleotide sequence and transcription of a rat tRNA(Phe) gene and a neighboring Alu-like element.

A bacteriophage gamma Ch4A clone containing a 22-kb rat DNA insert was isolated and found to contain a solitary tRNA(Phe)GAA gene and, 436 bp downstream of it, an Alu-like element. The nucleotide sequence of a 1141-bp DNA fragment containing these genes was determined. The rat tRNA(Phe)GAA gene, with the exception of an additional A in the extra arm, has a sequence identical to that of a rabbit liver tRNA(Phe). The Alu-like element belongs to the rodent B2 family of short interspersed repetitive nucleotide sequences. This repetitive element, B2Phe, is flanked by 12-bp direct repeats, contains an internal split promoter (block A and block B) for RNA polymerase III and is devoid of an A-rich segment at the 3' end. Like other members of the B2 family, the B2Phe element presents 64% sequence homology with rat serine tRNA and contains a serine (GCT) anticodon. Both tRNA(Phe)GAA gene and B2Phe element were found to be transcriptionally active in HeLa cell and Xenopus oocyte nuclear extracts. The tRNA(Phe) gene transcripts were processed during the course of transcription to form mature-size tRNA(Phe). The transcription efficiency of the B2Phe element was found to be an order of magnitude higher than that of the tRNA(Phe) gene. Competition experiments demonstrate that the B2Phe DNA can form a more stable transcription complex than the tRNA(Phe) gene and compete with it for binding of transcription factors.

Animals↗
PubMed1988

Correlation of in vitro immune defects with impaired gamma interferon response in human-immunodeficiency-virus-infected individuals.

65 patients belonging to known acquired-immune-deficiency-syndrome (AIDS) risk groups were tested for mitogen responsiveness to pokeweed mitogen, concanavalin A and phytohemagglutinin, percentages of peripheral blood CD4, CD8 and Leu7 lymphocyte subsets, serum neopterin levels, and gamma-interferon (gamma-IFN) concentrations in cell culture supernatants. Patients with clinical symptoms of human-immunodeficiency-virus infection showed reduced gamma-IFN production in vitro. The IFN concentrations were correlated significantly with mitogen-induced blastogenesis. High serum neopterin levels and decreased CD4/CD8 ratios were associated with diminished gamma-IFN levels. The percentage of Leu7 lymphocytes was increased in a group of patients with strikingly elevated gamma-IFN levels.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Abnormal amino-acid concentrations in the blood of patients with acquired immunodeficiency syndrome (AIDS) may contribute to the immunological defect.

The acquired immunodeficiency syndrome (AIDS) is accompanied by a metabolic disturbance. Serum samples from persons with antibodies against the AIDS associated human immunodeficiency virus (HIV/LAV/HTLV III) including persons without overt symptoms, patients with lymphadenopathy syndrome (LAS) and patients with AIDS or AIDS-related complex (ARC) contain on the average significantly elevated concentrations of arginine and glutamate. The serum from patients with overt AIDS contains also, on the average, significantly reduced concentrations of methionine and cystine. In vitro experiments revealed that the [3H]thymidine incorporation by mitogenically stimulated murine lymphocytes and cloned T cells is inhibited by an elevation of the extracellular glutamate concentration and augmented by the addition of cysteine. This suggests the possibility that the abnormal concentrations of glutamate and cystine in the blood of HIV-infected persons may contribute to the defect in the lymphoid system.

AIDS-Related Complex↗
PubMed1987

Mouse glutathione S-transferase Ya subunit: gene structure and sequence.

A mouse glutathione S-transferase gene encoding the Ya subunit was isolated and sequenced. The gene spans about 11 kb, contains seven exons, and encodes an mRNA of 841 nucleotides. Promoter elements, TATA and CAAT box sequences, were located 32 and 70 nucleotides upstream from the initiation of transcription site. The mRNA coding sequences of the mouse gene were highly homologous to a rat liver Ya mRNA species detected by cDNA cloning. The mouse Ya gene produces a 223-amino-acid polypeptide that differs from the 222-amino-acid rat Ya by 10 amino acid substitutions and a carboxyl terminus Phe-Lys-Ile-Gln instead of Phe-Lys-Phe. A genomic clone containing the last three exons of the rat Ya gene was also isolated, sequenced, and compared with the mouse Ya gene. An extensive sequence conservation (70-80%) in the 50 to 200 bases of introns at the exon-intron junctions as well as in the region beyond the cleavage-polyadenylation site of pre-mRNA was observed.

Amino Acid Sequence↗