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Biomedical subjects

N K Sharma

Publications and source records attributed to N K Sharma.

At least 37 records · Page 2Linked to original sources
PubMed1997

Anti-invasive activity of alkaloids and polyphenolics in vitro.

Invasiveness, the ability of certain tumour cells to migrate beyond their natural tissue boundaries, often leads to metastasis, and usually determines the fatal outcome of cancer. The need for anti-invasive agents has led us to search for possibly active compounds among alkaloids and polyphenolics. One hundred compounds were screened in an assay based on the confrontation of invasive human MCF-7/6 mammary carcinoma cells with fragments of normal embryonic chick heart in vitro. Anti-invasive activity was frequently found among chalcones having a prenyl group. Six compounds were found to inhibit invasion when added to the culture medium at concentrations as low as 1 microM. For at least three of them the anti-invasive effect could be associated with a cytotoxic effect on the MCF-7/6 cells, but not on the heart tissue. This selective cytotoxicity was substantiated by different methods, such as histology and growth assays (volume measurements, cell counts, MTT and sulforhodamine B assays). The anti-invasive effects of the compounds could neither be ascribed to induction of apoptosis nor to the promotion of cell-cell adhesion. Our data indicate that among the alkaloids and polyphenolics a number of molecules can inhibit growth and invasion of human mammary cancer cells via selective cytotoxicity.

Alkaloids↗
PubMed1996

Ductal (endometrioid) adenocarcinoma of the prostate: a clinicopathological study of 16 cases.

Sixteen cases of ductal (endometrioid) carcinoma of the prostate are presented. The tumour presents in elderly men (age range 65-87 years) with haematuria or obstructive symptoms. Serum prostate specific antigen may be normal or raised. On cytoscopy, there is often an exophytic lesion in the region of the verumontanum. Histologically, two variants are recognized: papillary and cribriform, of which there were eight cases each. Eight cases consisted of pure ductal carcinoma and seven were mixed, containing a variable proportion of micro-acinar carcinoma. The associated micro-acinar carcinoma had a Gleason score of at least 5. One case of carcinosarcoma with a ductal epithelial component was also included. All cases displayed positive immunohistochemical staining for prostate specific antigen and prostatic acid phosphatase and but were negative for the basal cell marker MA903. The tumour responds well to orthodox micro-acinar carcinoma therapy and appears notably sensitive to hormonal manipulation. Follow-up of the mixed group is restricted to a maximum of 3 years. Of the eight pure cases, five patients are still alive with survival periods of 11, 8, 7, 3 and 1 years. Three patients died of intercurrent disease of which one patient survived 12 years, having received no treatment. This tumour, therefore, can be regarded as having a good prognosis.

Acid Phosphatase↗
PubMed1995

Heterogeneity in chemical mutagen-induced chromosome damage after G2 phase exposure to bleomycin, ara-C and gentian violet in cultured lymphocytes of beta-thalassaemia traits.

Chemical mutagen-induced chromosome damage was analysed in cultured peripheral blood lymphocytes from beta-thalassaemia traits and healthy individuals. This was promoted by the fact that beta-thalassaemia trait is present in 1-17% of different population groups in India. To study mutagen-induced chromosome instability, G2 lymphocytes were exposed to bleomycin, ara-C or gentian violet in 48-h cultures. Spontaneous chromosome aberration frequencies in lymphocytes from beta-thalassaemia traits were found to be in the normal range. In all three clastogen-treated lymphocytes from beta-thalassaemia traits, there is a degree of hypersensitivity, when the results are averaged over a number of individuals, but some individuals overlap within the normal range. The heterogeneity in chemical mutagen sensitivity observed in beta-thalassaemia traits is discussed in terms of the oxidative damage consequent on the genetic and biochemical features peculiar to the beta-thalassaemia trait cell.

Adult↗
PubMed1994

Replantation in general dental practice.

This paper presents a comparison of the outcome of two cases where teeth, avulsed in sporting accidents, were replanted in general dental practice and have been reviewed for 5 years. Avulsed teeth which were stored dry, had a long extra-alveolar period and were splinted for a longer period of time, ultimately underwent replacement root resorption (case 1). There was no evidence of resorption, after 5 years, in the tooth that was stored in the patient's own saliva and was replanted within 45 minutes of being avulsed (case 2). The replantation procedure for these two cases was based on recent literature, which is also reviewed in this paper, and a protocol for the management of avulsed teeth is suggested.

Adolescent↗
PubMed1994

Heterogeneity of chromosome damage in beta-thalassaemia traits. An evaluation of spontaneous and gamma-ray-induced micronuclei and chromosome aberrations in lymphocytes in vitro after G0 and G2 phase irradiation.

This study is an attempt to evaluate the chromosomal radiosensitivity of beta-thalassaemia traits compared with healthy individuals from the general population, necessitated by the fact that beta-thalassaemia trait is present in 1-17% of different population groups in India and the chances of encountering them in radiation and chemical related industries do exist. Spontaneous chromosome aberration frequencies in peripheral blood lymphocytes from beta-thalassaemia traits were found to be in the normal range, whereas significantly higher frequencies of micronuclei (MN) were observed in thalassaemia traits. Based on MN frequency at 2 Gy, beta-thalassaemia traits fall into two distinct categories. A hypersensitive group with significant increase in radiation-induced MN over the control group, and a second group with MN frequency slightly above normal individuals. Even when compared with the fitted data at 2 Gy obtained from the pooled results of extensive dose-response investigations from 0.5-5 Gy gamma-rays with normal donors for MN, dicentrics and total aberrations, the difference between the means of MN frequencies in beta-thalassaemia traits and normals is significant. MN have a higher control level, a higher value for the alpha component, and much lower value for the beta component, when compared with total aberrations. Both in 2-Gy irradiated G0 lymphocytes as well as 0.5 and 1-Gy irradiated G2 lymphocytes, there is a certain degree of hypersensitivity when the results are meaned over a number of individuals, but some individuals overlap within the normal range. In G0 irradiated lymphocytes from beta-thalassaemia traits, the dicentric chromosome is the only aberration category in which the yield is seen to rise. The heterogeneity in chromosomal radiosensitivity observed in beta-thalassaemia traits is discussed in terms of the oxidative damage consequent to the genetic and biochemical features peculiar to the beta-thalassaemia trait cell. The data presented herein may have wider implications in radiation protection.

Chromosome Aberrations↗
PubMed1994

Bacteriological analysis of uncooked pork sausages in relation to public health.

One hundred and eighteen samples of uncooked pork sausages were analysed bacteriologically. The total aerobic plate count ranged from 1.8 x 10(8) to 9.2 x 10(8) CFU/g in the samples. High mean counts of Staphylococci, Enterococci, Micrococci, Bacillus cereus, Salmonella and Coliforms were observed. Staphylococcus aureus were encountered with count range 2.8 x 10(6) CFU/g to 7.4 x 10(6) CFU/g. The viable count of Escherichia coli ranged from 2.0 x 10(5) to 4.3 x 10(5) CFU/g. Clostridium perfringens were detected in 66.9% of samples with a count ranging from 3.9 x 10(2) to 1.1 x 10(7) Cl. perfringens/g. None of 118 samples contained Yersinia enterocolitica.

Animals↗
PubMed1994

A study to compare ibuprofen effervescent granules with ibuprofen tablets in the treatment of acute dental pain.

PURPOSE OF STUDY: To compare both the speed of onset and efficacy of the analgesia produced by the effervescent granule formulation with that produced by the conventional-release tablet formulation of ibuprofen in patients suffering acute dental pain and to record the incidence and severity of any adverse events. POPULATION STUDIED: Dental out-patients of either sex and over 16 years of age requiring surgical removal of unilateral or bilateral lower third molar teeth under general anaesthesia as day cases. METHODS: A total of 50 patients received the effervescent granules formulation of ibuprofen 600 mg (Brufen Granules) as study treatment and 50 received the 600 mg tablet formulation in this investigator-blind, parallel-group multiple-dose study. Surgery was performed under general anaesthesia by one or two dental surgeons. Patients received either one sachet of ibuprofen granules or one tablet of ibuprofen at six-hourly intervals for up to 24 hours once post-operative pain became moderate to severe. FINDINGS: Both treatments were shown to be efficacious in treating post-operative dental pain. The granules were found to give significantly better pain relief in the first 30 minutes following the first dose. This may be owing to a more rapid absorption from the granules formulation in these patients and/or a local action of ibuprofen in solution in the mouth. CONCLUSION: The effervescent soluble form of ibuprofen (Brufen Granules) is preferable to the conventional tablet form in managing the immediate dental pain experienced post-operatively by most patients because of its faster onset of action.

Acute Disease↗
PubMed1991

Colorimetric method for the determination of captafol (difolatan) in commercial formulations and residues on grains and apples.

A simple and rapid colorimetric method for the microdetermination of captafol (difolatan), based on its reaction with a dithiocarbamate, has been developed. The bright yellow colour which develops instantaneously on mixing the fungicide with the reagent is stable for at least 12 h. The method has been successfully adapted to the determination of captafol in its formulated products and residues on grains and apples.

Captan↗
PubMed1991

Hypoglycemic effect of swerchirin from the hexane fraction of Swertia chirayita.

A xanthone was isolated from the hexane fraction of the Swertia chirayita plant and identified as 1,8-dihydroxy-3,5-dimethoxyxanthone (swerchirin). It has a very significant blood sugar lowering effect in fasted, fed, glucose loaded, and tolbutamide pretreated albino rat models. The ED50 for 40% blood sugar lowering in CF male albino rats (body weight 140-165 g) is 23.1 mg/kg/oral. The possibility of its application in clinical therapy for diabetes mellitus needs exploration.

Animals↗
PubMed1990

Identification of Yersinia species by the API 20E.

A prospective study was performed to assess the effectiveness of the API 20E in the identification of 183 Yersinia isolates incubated at 28 degrees C for 18 to 24 h. The results showed an overall correct-identification rate of 90%, with positive predictive values for Yersinia enterocolitica and Yersinia frederiksenii of 94 and 92%, respectively. Yersinia intermedia results were unacceptable.

Bacteriological Techniques↗