First Report of the HLA-DQB1*03:575 Allele in a Kidney Transplant Recipient of European Descent.
The new HLA-DQB1*03:575 differs from HLA-DQB1* 03:03:02:01 by a single base substitution at exon 2.
Humans↗
Biomedical subjects
A Sharma
Publications and source records attributed to A Sharma.
Chromosomal alterations and sister chromatid exchanges induced by zirconium oxychloride in human lymphocytes in vitro with relation to age of donors.
Aqueous solutions of zirconium oxychloride were added to human peripheral blood lymphocyte culture. Cultures were set up from healthy donors of both sexes belonging to age groups of 0-10, 11-20, 21-30, 31-40, 41-50 and 51-60 years. Airdried Giemsa schedule was followed for preparation of chromosomal aberrations and micronuclei count. Flourescence plus Giemsa staining techniques were applied for the study of sister chromatid exchange. The endpoints screened were chromosome and chromatid breaks, dicentrics and rearrangements. The frequencies of chromosomal aberrations and sister chromatid exchanges induced were compared between the samples of different age groups. The frequency of CA could not be related to age of the donor. However, the frequency of SCE increased with increase in age of female donor.
Adolescent↗
Clastogenic effect of fenfluramine in mice bone marrow cells in vivo.
Fenfluramine, an amphetamine derivative used in the treatment of obesity, has been evaluated in vivo in the bone marrow cells of Swiss albino mice using two cytogenetic endpoints for assessing its genotoxic and clastogenic potentials. Concentrations of 0.75, 1.5, 3.0, and 5.0 mg/kg b.w. were administered orally for the study of sister chromatid exchange frequencies and chromosome aberrations (CA). SCE frequencies showed a positive dose response; 1.5 mg/kg being the minimum effective concentration. Fen caused a prolongation of cell cycle at all concentrations. Except for the minimum therapeutic dose (0.75 mg), all other doses (1.5, 3.0, and 5.0 mg) showed a significant increase in the percentage of damaged cells over that of the vehicle control. The degree of clastogenicity was directly proportional to the dosage used and inversely related with the duration of treatment. A gradual reduction of the clastogenic potential was observed after 12 and 24 hr of exposure, indicating that the maximum effect occurs at the middle or late synthetic phase of the cell cycle. This study, probably the first detailed screening of the drug for its genotoxicity, shows that Fen is moderately clastogenic and a DNA damaging agent in vivo.
Administration, Oral↗
Lymphoblastoid cell adhesion mediated by a dimeric and polymeric endogenous beta-galactoside-binding lectin (galaptin).
Glutaraldehyde-polymerized human splenic galaptin, a beta-galactoside-binding lectin, was demonstrated to have enhanced hemagglutinating and asialofetuin binding activity relative to native dimeric galaptin when these lectins were present in solution. The polymerized lectin consisted primarily of 2-, 4- and 12-membered species after reductive alkylation. Both forms of galaptin bound, at 4 degrees C, to saturable B lymphoblastoid cell surface receptors. Estimates obtained by Scatchard analyses, with the binding data expressed in terms of 14.5 kDa subunit molarity, were 5 x 10(7) binding sites/cell with affinity constant Ka = 2.2 x 10(5) M for dimeric galaptin and 17 x 10(7) binding sites/cell with Ka = 3.4 x 10(5) M-1 for polymeric galaptin. Both forms of galaptin adsorbed to polystyrene with high efficiency; however, only plastic-adsorbed polymeric galaptin mediated adhesion of lymphoblastoid cells. Cell adhesion was inhibited by lactose. Plastic-adsorbed polymeric galaptin bound asialofetuin more efficiently than dimeric galaptin. Asialofetuin binding was inhibited 65% and 30-50% by lactose for plastic-adsorbed polymeric and dimeric galaptin, respectively. Native fetuin bound to the adsorbed dimeric galaptin in a lactose-insensitive manner. These data indicate that cell surface receptor-galaptin interaction is carbohydrate specific whereas polystyrene-adsorbed galaptin may demonstrate protein-protein interactions with soluble ligands.
Asialoglycoproteins↗
Genetic markers in relation to different exposures.
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Adult↗
Interaction between two group IV metals--lead and zirconium--in bone marrow cells of Mus musculus in vivo.
The interaction between two group IV metals, the highly toxic lead and the relatively inactive and low toxic zirconium, was studied in the bone marrow chromosomes of Mus musculus in vivo. Low and high doses of zirconium oxychloride were fed orally to the experimental mice (i) 2 h before, (ii) 2 h after or (iii) together with different doses of lead nitrate. Protection against lead-induced clastogenicity was observed only when the lower dose of zirconium was administered prior to lead. All other combinations gave an additive or synergistic effect as was seen by significant increases in the frequencies of chromosomal aberrations.
Animals↗
Comparison of the clastogenic effects of antimony trioxide on mice in vivo following acute and chronic exposure.
Antimony trioxide (Sb2O3), in aqueous suspension, was administered by gavaging to mice and monitored for chromosomal aberrations in bone marrow and sperm head abnormalities in germ cells. Acute exposure to the doses followed by observations after 6, 12, 18 and 24 h did not show any clastogenic effects. Chronic exposure daily to different doses for periods up to 21 days induced chromosomal aberrations in bone marrow. The frequencies were dose-dependent to a significant extent but no relationship could be seen with the sex of the animal. The findings indicate the harmful effects of cumulative exposure for prolonged periods to Sb2O3, which is being increasingly used in various industries.
Administration, Oral↗
Effect of domestic processing, cooking and germination on the trypsin inhibitor activity and tannin content of faba bean (Vicia faba).
The effects of domestic processing methods like soaking for 12 h, dehulling, ordinary cooking of whole as well as dehulled seeds at 15 lbs/inch2 pressure for 15 and 25 min, and germination for 24, 36 and 48 h were observed on trypsin inhibitor (TIA) and tannin content of two varieties of faba bean viz. VH-131 and WF. A non-significant reduction in TIA was observed on soaking and dehulling, while tannins showed a reduction of 42 and 51% on soaking in VH 131 and WF, respectively. Dehulled seeds showed a decline in tannin content by 70 to 73% in two varieties. There was a significant reduction in TIA (75-76 per cent) and tannin (76-81%) on cooking, while autoclaving for 25 min almost completely eliminated both of these stress factors. Germination of seeds for 48 h led to a reduction of 64-65% in TIA and 90-91% in tannins, which was more than germination for 24 and 36 h. Soaked seeds gave positive results of both these antinutrients.
Fabaceae↗
Modifying effect of iron on lead-induced clastogenicity in mouse bone marrow cells.
Essential trace elements such as iron (Fe) are known to interact with nonessential metals like lead (Pb), influencing its metabolism. Ferric chloride and lead nitrate were administered intraperitoneally to Swiss albino mice Mus musculus singly and successively, with or without a time gap of 1 h, to study the degree of protection, if any, afforded by iron against the clastogenic effects induced by Pb in bone marrow cells. A decrease in the frequency of lead-induced chromosomal aberrations was observed when Fe was given together with or prior to Pb administration.
Animals↗
Zirconium. An abnormal trace element in biology.
The action of Zirconium (Zr) on biological systems presents an enigma. It is ubiquitous, being present in nature in amounts higher than most trace elements. It is taken up by plants from soil and water and accumulated in certain tissues. The entry into animal systems in vivo is related to the mode of exposure and the concentration in the surrounding environment. Retention is initially in soft tissues and then slowly in the bone. The metal is able to cross the blood brain-barrier and is deposited in the brain and the placental barrier to enter milk. The daily human uptake has been known to be as high as 125 mg. The level of toxicity has been found to be moderately low, both in histological and cytological studies. The toxic effects induced by very high concentrations are nonspecific in nature. Despite the presence and retention in relatively high quantities in biological systems, Zr has not yet been associated with any specific metabolic function. Very little information is available about its interaction with the compounds of the genetical systems, such as nucleic acids. Apparently, the metal is neither an essential nor toxic element in the conventional sense. However, the increasing exposure to this element through its increasing use in new materials and following radioactive fallout, has increased the importance of the study of its effects on living organisms. The tetravalent nature of the ionic state and the high stability of the compounds formed are important factors that need to be considered, as also the accumulation of this element in the brain, reminiscent of the relationship between Al3+ and Alzheimer's disease.
Animals↗
Severe subpulmonic outflow obstruction caused by aneurysm of the membranous ventricular septum: diagnosis by transesophageal echocardiography.
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Adult↗
Treatment of edentulous maxillae with osseointegrated implants.
Edentulous maxillae can be restored with implant supported fixed restorations containing denture teeth on a metal framework, implant-retained removable overlay prostheses, or porcelain fused-to-metal fixed prostheses. Esthetics and hygiene access are two important factors in determining the restoration best suited for each patient. Treatment planning considerations and treatment procedures for the various techniques are discussed.
Dental Implants↗
Protein energy malnutrition and the nervous system.
Protein-energy malnutrition (PEM), a natural ramification of poverty, continues to be a perennial source of concern to a large segment of the world population. The developing nervous system of a child is specially vulnerable to deprivations in nurture. Peripheral nerve and muscle derangements are clinically evident by weakness, hypotonia and hyporeflexia in accordance with severity and duration of PEM. Motor and sensory nerve conduction studies exhibit significant abnormalities and often furnish useful and ominous correlation with grades of PEM. The human sural nerve histology in cases of severe PEM is characterized by persistence of small myelinated fibres, striking failure of internodal elongation and significant segmental demyelination. Young rhesus monkeys are ideal experimental PEM models and they show myopathic EMG changes amenable to rehabilitation. Muscle pathology comprises obliteration of cross-striations, streaming of Z bands, increased interfibrillary spaces, mitochondriomegaly and small-for-age fibres. Radioisotope assays reveal anomalous incorporation into various nerve and muscle constituents. Central nervous system, specially the neuropsychological functions are affected in a lasting manner. Learning deficits, behavioural problems and manual indexterity are most obtrusive features.
Animals↗
Pregnancy enhances cardiotoxicity of cocaine: role of progesterone.
Contraction dynamics of isolated papillary heart muscles from nonpregnant, pregnant, and progesterone-treated nonpregnant Long Evans rats were studied during exposure to cocaine. With increasing cocaine concentrations from 10(-16) to 10(-4) M, papillary muscles from nonpregnant rats demonstrated a biphasic pattern of positive, then negative, inotropy. Only negative inotropy with increasing cocaine concentrations was observed in papillary muscles from pregnant and progesterone-treated nonpregnant rats. Papillary muscles from pregnant and progesterone-treated nonpregnant rats became nonfunctional at cocaine concentrations 1-4 orders of magnitude lower than those for nonpregnant rats. These findings demonstrate that pregnancy and progesterone treatment alter cocaine effects upon cardiac papillary muscle function and response patterns and shift the cocaine dose-function curve to the left when compared to the nonpregnant group. We conclude that pregnancy increases the direct cardiotoxicity to cocaine, and progesterone may be responsible for this enhanced cocaine toxicity.
Animals↗
Cytotoxicity of tin on human peripheral lymphocytes in vitro.
The comparative effects of inorganic and organic tin compounds on chromosomes were assessed in human peripheral blood lymphocytes of healthy donors 20-40 years of age. The endpoints observed were chromosomal abnormalities, sister-chromatid exchanges (SCEs) and cell cycle kinetics. The maximum concentrations which reduced the replicative index by about 50%, of stannic chloride and trimethyltin chloride were 40 micrograms and 2 micrograms per culture respectively. The tested doses were 20 micrograms and 10 micrograms of stannic chloride and 1 microgram and 0.5 microgram of trimethyltin chloride. Both doses of stannic chloride induced a much higher frequency of chromosomal abnormalities (P less than 0.05-P less than 0.001) and a greater reduction of cell cycle kinetics than the corresponding relative doses of trimethyltin chloride. The frequencies of SCEs/cell induced by the latter were, however, slightly higher than those induced by the former.
Cell Cycle↗
Relative protection given by extract of Phyllanthus emblica fruit and an equivalent amount of vitamin C against a known clastogen--caesium chloride.
Aqueous extracts of Phyllanthus emblica L. fruit and an equivalent amount of vitamin C were administered orally by gavage to laboratory-bred Swiss albino mice for 7 days in order to evaluate the protection afforded by the two extracts against clastogenic effects of different doses of caesium chloride (CsCl) on bone marrow cells of Mus musculus in vivo. Both pretreatments significantly reduced the frequency of chromosome aberrations induced by CsCl given at three different doses, indicating that vitamin C, an essential component of P. emblica extract, was the effective agent in protecting against the clastogenicity of the metal salt.
Animals↗
Isolation of lactose-binding lectins from axolotl (Ambystoma mexicanum).
1. Lactose-inhibitable hemagglutination activity was identified in extracts of axolotl (Ambystoma mexicanum) larvae. 2. Two types of lectin were isolated from extracts by affinity chromatography on lactose-Sepharose. 3. A thiol-independent lectin of subunit mol. wt 15 kDa and a thiol-dependent lectin of subunit mol. wt 18 kDa were identified. 4. The 15 kDa and a 18 kDa polypeptides were weakly reactive with polyclonal anti-human galaptin serum.
Ambystoma↗
Modification of metal-induced micronuclei formation in mouse bone marrow erythrocytes by Phyllanthus fruit extract and ascorbic acid.
The comparative efficacy of Phyllanthus emblica fruit extract, and its main constituent, ascorbic acid, in modifying the cytotoxic action of lead and aluminium was evaluated in vivo in bone marrow cells of Mus musculus. Oral administration of Phyllanthus emblica fruit extract for 7 days before exposure to the metals through intraperitoneal injections reduced the frequency of micronuclei induced by all doses of both metals. Priming with comparable doses of synthetic ascorbic acid reduced micronuclei formation induced by both doses of aluminium and only the lower dose of lead. With the higher dose of lead (20 mg/kg body wt.) priming with ascorbic acid increased the frequency of micronuclei when compared with mice administered lead alone. The greater efficacy of Phyllanthus fruit extract in alleviating metal-induced clastogenicity may be due to the combined action of all ingredients in the crude extract, rather than to ascorbic acid alone.
Aluminum↗