Biomedical subjects

K Banki

Publications and source records attributed to K Banki.

23 records · Page 2Linked to original sources

PubMed1992

Human T-cell leukemia virus type I or a related retrovirus in patients with mycosis fungoides/Sézary syndrome and Kaposi's sarcoma.

Antibodies reactive with human T-cell leukemia virus type I (HTLV-I) proteins p19, p24, gp46, p56, and gp68 were detected in four of 27 patients with mycosis fungoides/Sézary syndrome (MF/SS) and one patient with Kaposi's sarcoma using radioimmunoprecipitation and Western blot analysis. Seroreactivity patterns to HTLV-I proteins of MF/SS sera were indeterminate or limited in comparison with sera of patients with adult T-cell leukemia/lymphoma. HTLV-I gag- and tax/rex-specific DNA was demonstrated in peripheral blood from three of the MF/SS patients and from the patient with Kaposi's sarcoma by the polymerase chain reaction. HTLV-I-specific DNA sequences were not detected in a cohort of seven seronegative MF/SS patients. The frequency of HTLV-I infection was four of 27 or 14.8% among the MF/SS patients, which is several hundredfold higher than in normal blood donors. The present data suggest a possible association of HTLV-I or a related retrovirus with mycosis fungoides/Sézary syndrome and Kaposi's sarcoma.

Adult↗

PubMed1992

Human T-cell lymphotropic virus (HTLV)-related endogenous sequence, HRES-1, encodes a 28-kDa protein: a possible autoantigen for HTLV-I gag-reactive autoantibodies.

The presence of a human T-cell lymphotropic virus (HTLV)-related endogenous sequence, HRES-1, in the human genome has been documented. The HRES-1 genomic locus is transcriptionally active and contains open reading frames. Antibodies 232 and 233, specific for synthetic peptides pep14-24 and pep117-127, corresponding to two nonoverlapping HTLV-related regions in the longer open reading frame of HRES-1, recognize an identical 28-kDa protein in H9 human T cells. Thus, HRES-1 is a human endogenous retroviral sequence capable of protein expression. HRES-1/p28 is localized to the cytoplasm and nuclear bodies. While HTLV-I-specific antibodies react with HRES-1 peptides, antibody 233 cross-reacts with HTLV-I gag p24 protein. Three consecutive highly charged amino acid residues, Arg-Arg-Glu, present in both HRES-1 pep117-127 and HTLV-I gag p24 are likely to be the core of cross-reactive epitopes. The prevalence of antibodies to HRES-1 peptides pep14-24 and pep117-127 was determined in 65 normal blood donors and 146 patients with immunological disorders. Sera of patients with multiple sclerosis (19 out of 65, 29%), progressive systemic sclerosis (4 out of 17, 23%), systemic lupus erythematosus (4 out of 19, 21%), and Sjogren syndrome (2 out of 19, 10%) contained significantly higher HRES-1 peptide binding activity than sera of normal donors. Sera of patients with AIDS showed no specific binding to HRES-1 peptides. Nine of 30 HRES-1-seropositive patients showed immunoreactivity to HTLV-I gag p24. The data indicate that HRES-1/p28 may serve as an autoantigen eliciting autoantibodies cross-reactive with HTLV-I gag antigens.

Amino Acid Sequence↗

PubMed1989

Inhibition of rat kidney mitochondrial DNA, RNA and protein synthesis by halogenated cysteine S-conjugates.

The effect of S-(1,2,3,4,4-pentachloro-1,3-butadienyl)-L-cysteine (PCBC), a metabolite of the nephrocarcinogen hexachloro-1,3-butadiene, and related cysteine S-conjugates on rat kidney mitochondrial DNA, RNA and protein synthesis was studied. Chloramphenicol-sensitive mitochondrial protein synthesis was inhibited (greater than 95%) by 0.5 mM PCBC. Similarly, mtRNA synthesis was inhibited (approximately 80%) by 0.125 mM PCBC, and mtDNA synthesis was inhibited by 0.125-0.5 mM PCBC. The cysteine S-conjugates S-(2-chloro-1,1,2-trifluoroethyl)-L-cysteine and S-(1,2-dichlorovinyl)-L-cysteine were less potent inhibitors. The effects of PCBC on DNA, RNA and protein synthesis were blocked by aminooxyacetic acid, an inhibitor of cysteine conjugate beta-lyase, thus demonstrating the essential role of beta-lyase in the bioactivation of PCBC. In mitochondria incubated with PCBC for 1 h, 60% of the high mol. wt DNA was degraded. Agarose gel electrophoresis of mtDNA showed that the supercoiled form was converted to the relaxed circular form and to shorter linear fragments. These studies show that PCBC, a metabolite of the nephrocarcinogen hexachloro-1,3-butadiene, has important effects on mitochondrial macromolecule synthesis and on the mitochondrial genome.

Animals↗

PubMed1986

Metabolism of S-(2-chloro-1,1,2-trifluoroethyl)-L-cysteine to hydrogen sulfide and the role of hydrogen sulfide in S-(2-chloro-1,1,2-trifluoroethyl)-L-cysteine-induced mitochondrial toxicity.

The nephrotoxic cysteine S-conjugate S-(2-chloro-1,1,2-trifluoroethyl)-L-cysteine (CTFC) is metabolized by kidney homogenates and subcellular fractions to pyruvate and a reactive thiol, which is cytotoxic and partially decomposes to yield hydrogen sulfide and thiosulfate. Although hydrogen sulfide is a potent mitochondrial poison, the mitochondrial toxicity of CTFC is not attributable to hydrogen sulfide formation, as shown by different sites of inhibition of mitochondrial respiration by CTFC and hydrogen sulfide. The efficient mitochondrial oxidation of hydrogen sulfide apparently serves to protect mitochondria against the toxic effects of hydrogen sulfide generated from CTFC.

Animals↗

PubMed1984

Effects of indomethacin and naproxen on renal p-amino-hippurate (PAH) excretion in rats during postnatal development.

Effects of the cyclooxygenase inhibitors indomethacin and naproxen on renal PAH excretion were studied in volume-expanded and sodium-loaded, conscious rats of different ages. Indomethacin and naproxen reduce renal PAH excretion in 5- and 10-day-old rats but not in rats of older ages. Findings can be explained by a decrease in glomerular filtration rate. In addition, a competitive inhibition of PAH transport by the organic acids indomethacin and naproxen must be mentioned. Until now it is not known whether or not there is a direct or indirect influence of prostaglandins on processes involved in tubular PAH transport.

Aging↗