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Biomedical subjects

R K Das

Publications and source records attributed to R K Das.

At least 37 records · Page 2Linked to original sources
PubMed1992

Haematological and coagulation profile in acute falciparum malaria.

The haematological and coagulation profile of 30 cases of acute falciparum malaria were studied. Anaemia, mostly normocytic, normochromic, was observed in 86.7% of cases majority of whom had complications. Severe anaemia (HB < 6gm.) observed in 10% of cases was associated with 100% mortality. Leucocytosis and leucopenia were observed in 13.3% and 6.6% of cases respectively. 90% of cases had thrombocytopenia, the lowest count recorded being 26,000/- cmm. 16.7% of cases had evidence of intravascular coagulation but manifested as generalised bleeding in only one case. Bone marrow aspiration done in 10 cases revealed no abnormality, except for falciparum parasites observed in 2 cases.

Adult↗
PubMed1991

Human cerebral malaria: characterization of malarial antibodies in cerebrospinal fluid.

Anti-malarial antibodies were quantified in cerebrospinal fluid (CSF) of 17 cases of cerebral malaria, 16 presumptive cases (no demonstrable parasitaemia in peripheral blood but responding to i.v. quinine therapy) of cerebral malaria, and 15 controls. A schizont-enriched Plasmodium knowlesi antigen was used in an ELISA. Anti-malarial antibodies of IgA and IgM isotypes were not detectable in most of the CSF samples analysed, although serum antibody titres were high. However, 88% of CSF from cerebral malaria and 56% of presumptive cerebral malaria cases had significant levels of IgG anti-malarial antibodies in comparison to control CSF. The antibody levels did not correlate with the severity of coma but correlated well with the duration of coma. The CSF malarial antibody titres were independent of degree of parasitaemia. The possible role of CSF anti-malarial antibodies in cerebral malaria in the light of recent demonstrations of intrathecal synthesis of immunoglobulins and deposition of immune complex in cerebral tissues is discussed.

Animals↗
PubMed1991

Sonographic detection of foreign bodies of the extremities.

A prospective study to assess the accuracy of ultrasound in the detection and localization of foreign bodies of the extremities was undertaken. Forty-five patients with clinical suspicion of foreign bodies were included in the study. Among 20 patients with radio-opaque foreign bodies, ultrasonic detection of foreign bodies was achieved in 19 patients. In 25 patients, with no radiographic evidence of foreign body, ultrasonic detection of foreign bodies was made in seven patients and among these foreign bodies were confirmed and removed at surgery in five patients. Accurate pre-operative ultrasonic localization of foreign bodies was carried out in three patients.

Evaluation Studies as Topic↗
PubMed1990

Evaluation of genotoxicity of clofazimine, an antileprosy drug, in mice in vivo. I. Chromosome analysis in bone marrow and spermatocytes.

Clofazimine, an antileprosy drug, was tested for its cytogenetic effect in mouse bone marrow and testis. Bone marrow metaphase analysis in adults treated directly for different periods (1, 2 and 4 weeks, 40 mg/kg/day) and with different doses (4, 20 and 40 mg/kg/day for 7 days) as well as in young animals exposed through lactation for different periods (2, 3, and 4 weeks) revealed significant increases in chromosomal aberrations over the controls. Analysis of diakinesis-metaphase I stages also exhibited a significantly elevated incidence of chromosome aberrations over controls after treatment for different periods. On the basis of the present result the drug may be considered a potential clastogen in mice.

Animals↗
PubMed1990

Evaluation of genotoxicity of clofazimine, an antileprosy drug, in mice in vivo. II. Micronucleus test in bone marrow and hepatocytes.

The antileprosy drug, clofazimine, was tested for its possible genotoxicity using micronucleus (MN) tests in mice. A significantly higher incidence of MN in bone marrow erythrocytes, particularly in polychromatic erythrocytes, as well as in regenerated hepatocytes revealed a positive clastogenic effect of the drug. The drug also had a marked antimitotic effect as indicated by a negative correlation with the dose.

Animals↗
PubMed1988

Spermatocyte chromosome alterations in mice inoculated with antirabies vaccine and tetanus toxoid separately and in combination.

The genotoxic potential of antirabies vaccine (ARV) and tetanus toxoid (TT) inoculated separately and in combination was evaluated by spermatocyte chromosome analysis in mice. Adult males were vaccinated with a dose of 1 ml/kg ARV once daily for 7 days, or with a dose of 1 ml/kg TT once only, or with both (TT being administered along with the last dose of ARV). Spermatocytes were analyzed over 1-6 post-vaccination weeks for numerical and structural changes as well as for univalent formation. Controls were age matched non-vaccinated males. Significantly high incidences of structural aberrations from wk 4 onwards and at wk 6 following inoculation of ARV and TT, respectively, suggested susceptibility of stem cells to the vaccines. Combined vaccination (ARV plus TT) showed an additive effect. Occurrence of univalents involving autosomes as well as sex chromosomes was very common in all the vaccinated groups, the sex chromosomes being prevalently involved. Structural aberrations showed a positive correlation with time, while univalent formation showed a negative correlation. It appears that factors for clastogenicity and univalent formation are different for both the vaccines.

Animals↗
PubMed1988

Genotoxic potential of diethylcarbamazine, an antifilarial drug.

The mutagenic potential of diethylcarbamazine (DEC) was evaluated by metaphase chromosome analysis and the micronucleus test in bone marrow cells of mice. Both assay systems revealed clastogenicity, although not severe. The time-response study of metaphase chromosomes exhibited an early effect; at 72 h post-treatment the effect came down to the control level. The dose-response analysis showed significantly elevated frequencies of micronuclei (MN) for all the doses tested, but failed to show any influence of the dose on the induction of MN. Data on mitotic index (MI) indicated a lack of cell cycle inhibition. The decrease in aberration frequency with the lapse of time can be probably attributed to the elimination of the drug and its metabolites from the body.

Administration, Oral↗
PubMed1988

A simplified method for micronucleus preparation from hepatic cells.

A simplified method for micronucleus preparation from regenerating hepatocytes has been developed. Small pieces of the regenerating portion of the liver are incubated in 1% sodium citrate solution containing collagenase Type 1A (final concentration 0.005% w/v) at 37 C for 10-15 min with occasional gentle agitation. The larger particles are discarded. Drops of the thick homogeneous citrate suspension of liver cells are put on the slides and drawn back immediately into the pipette, leaving only the drop marks. This simplified method, which gives good preparations with many intact hepatocytes, was validated in a model experiment using mitomycin C. The data revealed a distinct dose-response effect.

Animals↗
PubMed1988

Cytogenetic effect of dapsone, an antileprotic drug, in the mouse in vivo system.

Potential genotoxicity of dapsone was evaluated in mice following in vivo cytogenetic assays. Adult male mice treated with different doses (20 mg, 40 mg, or 80 mg/kg/day for 4 weeks) and for different periods (40 mg/kg/day for 2, 4, or 8 weeks) provided bone marrow and testes for mitotic and meiotic chromosome analyses, respectively. A dose-response (20 mg, 40 mg, or 80 mg/kg/day for 2 weeks) analysis was done with a separate set of mice using a micronucleus test (MNT). Untreated mice served as controls. Both the metaphase analysis and MNT in bone-marrow cells revealed significantly higher incidences of clastogenicity for all of the dose levels and treatment periods. Chromosome aberrations, with and without gaps, in bone-marrow metaphases showed a positive correlation with the doses, but not with the treatment periods. Correlation was also lacking in the MNT. In the meiotic cells, the incidences of chromosome aberrations increased significantly with the highest dose and with the longest period of treatment.

Animals↗
PubMed1984

A 39,X/40,XY/41,XYY mosaic male mouse.

Cytogenetic analyses of bone marrow and gonadal cells in a male mouse, which appeared to be normal, revealed mosaicism in both tissues. Three chromosome complements, 39,X, 40,XY, and 41,XYY, were found in both bone marrow and spermatogonia, while only the last two complements were found in spermatocytes. In this mouse, unlike in the human, the XYY cells showed a proliferative advantage over the XY cells. In XYY cells at diakinesis/metaphase I the gonosomes showed all possible types of association, and a pairing advantage of the X chromosome was clearly demonstrated. The fertility of the mouse was not determined. However, since the epididymal sperm count was reduced by only 55% and the incidence of sperm head abnormality was near normal, it is not evident that the mouse was sterile.

Animals↗
PubMed1983

Induction of sperm head abnormalities in mice by three tranquilizers.

Toxic effects of diazepam (DZ), chlordiazepoxide (CDZ) and nitrazepam (NZ) on the spermatozoa of mice have been studied at the end of 1, 3, 4, 6, 8 and 12 weeks after 15 days repeated treatment with a daily oral dose of 0.5 mg. Different types of abnormalities involving both shape and size of the sperm head were noticed. Qualitatively NZ produced the maximum number of abnormal types. The incidences of abnormal sperm heads were significantly high in all the test weeks in the NZ series, at weeks 1 and 6 after DZ treatment, and at weeks 3, 4 and 6 after CDZ treatment. All three drugs produced maximum effects at week 6. The varying effects induced by the three benzodiazepines seem to be due to their differential pharmacokinetics.

Animals↗