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Biomedical subjects

S N Das

Publications and source records attributed to S N Das.

At least 37 records · Page 2Linked to original sources
PubMed1998

Effect of cyclosporine on fertility in male rats.

The effect of cyclosporine (CsA) on fertility has assumed greater importance with the increasing numbers of pediatric transplantations being performed all over the world. Conflicting reports on the effects of CsA on sex hormones are available. This experimental animal study was designed to examine the effect of CsA on testicular weight, sperm counts, seminiferous tubular diameter (STD), testicular morphology, DNA flowcytometry, sex hormone levels, and fertility in male rats. Those rats who received CsA (20 mg/kg per day) showed significant reductions in testicular weight (P < 0.05), sperm count (P < 0.01), Johnsen score (P < 0.05), STD (P < 0.01), serum testosterone levels (P < 0.05), haploid cell population (P < 0. 001) in the testis, and fertility (P < 0.001) compared to those receiving CsA 10 mg/kg per day and control rats. These findings will have an important bearing for children receiving cyclosporine for long periods to guide the physician in optimally adjusting long-term treatment.

Animals↗
PubMed1998

Fertility and unilateral undescended testis in the rat model II.

Continuing experimental work on the effect of experimentally created unilateral undescended testis (UL-UDT) in neonatal rats, this study examined the fertility and correlated it to contralateral (CL) testicular morphology, seminiferous tubular diameter (STD), DNA flowcytometry, and the presence of serum anti-sperm antibodies (ASA) at 120-135 days of age. In our previous reported work, the fertility of rats with UL-UDT at 65-80 days of age was the same as that of controls. In the present study the rats with UL-UDT had significantly reduced fertility (P < 0.01) compared to controls, even though the Johnsen scores and mean STD of the CL testicular tissue were comparable. DNA flowcytometry demonstrated a significant decrease (P < 0.001) in haploid cell population in the CL testicular tissue of rats with UL-UDT. Furthermore, the rats with UL-UDT who either received an immunosuppressive or in whom the UDT was excised early showed almost normal fertility and DNA histograms like those of controls. Significantly high titres of serum ASA were detected only in the group with UL-UDT when tested at 135 days of age. From these results, in combination with earlier results on similar work, it may be inferred that UL-UDT causes immunologically-mediated, progressive damage to the CL descended testis, leading to a decrease in fertility in rats.

Aging↗
PubMed1998

Cell surface expression of 70 kDa heat shock protein in human oral dysplasia and squamous cell carcinoma: correlation with clinicopathological features.

To understand the role of 70 kDa heat shock protein (HSP70) in the pathogenesis of oral cancer, its expression was studied in human normal, premalignant and malignant oral mucosa. Cell surface expression of HSP70 was assessed in oral tissue specimens by flow cytometric analysis using a mouse monoclonal antibody against HSP70. A significant increase in cell surface expression of HSP70 was observed as the tissue progressed from normal to dysplasia towards carcinoma. Correlation of HSP70 expression with clinicopathological features showed a positive association with the severity of dysplasia. Among the oral tumours assessed, a significantly positive association was observed between HSP70 expression and dedifferentiation of oral squamous cell carcinomas (SCCs). Poorly differentiated tumours showed significantly higher levels of HSP70 expression on the surface of tumour cells, compared with well differentiated carcinomas (P < 0.05). Cell surface expression of HSP70 was observed to be significantly higher in clinically advanced stage tumours (T3/T4), compared with T1/T2 stage tumours (P < 0.05). The variation in cell surface expression of HSP70 in normal, dysplastic and malignant oral lesions suggests that it is differentially expressed during oral tumorigenesis and may play a specific role in the pathogenesis of oral cancer.

Carcinoma, Squamous Cell↗
PubMed1998

Complement-regulatory protein expression and activation of complement cascade on erythrocytes from patients with rheumatoid arthritis (RA).

It has been previously reported that the expression of the complement receptor, CR1, on erythrocytes is reduced in patients with RA and that the reduced expression of CR1 is related to disease activity. In this study we investigate the role of other regulatory proteins, i.e. decay-accelerating factor (DAF) and CD59 (membrane inhibitor of reactive lysis), in the pathogenesis of RA by checking the expression of DAF and CD59 on erythrocytes of RA patients to establish whether reduced expression of DAF and CD59 on erythrocytes could be related to increased ability of erythrocytes to activate complement in RA. Flow cytometry was used to measure the expression of DAF and CD59 on erythrocytes from RA patients as well as the deposition of C3 fragments occurring in vivo or after in vitro complement activation. Significantly reduced expression of DAF and CD59 was observed on erythrocytes of RA patients. A significant inverse relationship was observed between DAF expression and in vitro complement activation, whereas no significant relationship between CD59 and complement activation was observed. Finally, we demonstrated an inverse relationship between CH50 activity and DAF expression. Thus, determination of DAF on erythrocytes can emerge as an additional tool in the assessment of extent of complement activation in RA.

Adolescent↗
PubMed1997

Differential expression of multidrug resistance gene product, P-glycoprotein, in normal, dysplastic and malignant oral mucosa in India.

Multidrug resistance (MDR) in human cancer is often associated with over-expression of the mdr-1 gene, which encodes a 170-kDa transmembrane protein, termed P-glycoprotein (P-gp). We evaluated the immunoreactivity of P-gp in oral tissues at different stages of tumorigenesis in the Indian population by flow cytometry, using the MRK-16 monoclonal antibody, which recognizes an external epitope of P-gp. The expression of P-gp was studied in human oral normal tissues (12 cases), dysplastic lesions (13 cases), primary untreated squamous-cell carcinomas (12 cases) and recurrent tumors (18 cases). Quantitative flow-cytometric analysis of P-gp expression showed a significant increase in P-gp levels in untreated primary oral tumors (p < 0.01) and in dysplastic lesions (p < 0.05) as compared with normal oral tissues. A marked significant increase in P-gp expression was observed in recurrent oral carcinomas as compared with normal oral tissues (p < 0.001) and dysplastic lesions (p < 0.01). Among recurrent tumors, a significant increase in the level of P-gp was observed in T4-stage tumors as compared with T3-stage tumors (p < 0.01). We conclude that P-gp is differentially expressed during oral tumorigenesis, and may be an indicator of the biological behavior of oral malignancies.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

A survey of 4478 biopsy specimens of oral lesions.

A surgery of 4478 biopsy specimens in dental institute in India was carried out to compare and correlate results obtained from such studies carried out elsewhere. The study revealed that there are more than 150 common and rare oral diseases which are diagnosed and treated by dentists. 13 common diseases comprised majority (60.37%) of the biopsy specimens studied. Of these, tumors (25.53%) and Cysts (14.38%) constituted the majority of the bulk. The study also shows that most of the benign tumors were mesenchymal in origin (almost 5.5:1) while malignant tumors were epithelial (almost 20:1) in origin. Cystic lesions included the most common radicular cyst (7.12%) and the rare hydatid cyst (one case reported). Gingival hyperplasia mainly due to local aetiology, constituted the 3rd largest group. The purpose of this report is to provide some information about the type and frequency of oral lesions usually diagnosed, with the help of histopathological examination in India.

Biopsy↗
PubMed1991

A study on the B cell activity in protein deficient rats exposed to methyl isocyanate vapour.

The effect of MIC on the humoral immunity of the malnourished (protein deficient) subjects has been investigated. A single exposure of MIC (1.60 mg/l) on protein deficient rats showed no significant change in the body weight and mortality rate compared with the normal but the serum protein levels were found significantly low (P less than 0.01) in the protein deficient diet fed control (PDC) ones. Both PDC and protein deficient MIC exposed (PDMIC) rat showed diminished B-cell proliferation with the optimal dose of LPS, compared to the NDC and normal diet fed MIC exposed (NDMIC) group. Furthermore significant suppression (P less than 0.01) in the B-cell activation by LPS was observed in the PDMIC compared to PDC. The total IgM level in PDMIC was 43% less while 26% higher in NDMIC compared to NDC. The total IgG level in PDMIC and NDMIC was higher (20%) compared to NDC, while 25% less in PDC. The antigen specific B-cell immunity was affected in PDMIC, PDC and NDMIC. As the terminal differentiation process of B-cells were found equally affected in both PDC and NDMIC, it appears that MIC has no synergistic effect on the humoral immunity of the protein malnourished host.

Animals↗
PubMed1991

High prevalence & heterogenicity of thalassaemias in Orissa.

High incidence of alpha thalassaemias (estimated from detection of Hb Bart's from cord blood), Hb constant spring (CS) and high A2 beta thalassaemia trait (estimated from normal adult subjects) were detected in 12.6, 15 and 8 per cent people of coastal Orissa (with less than 5% tribal population) respectively. Quantitation of Hb Bart's suggest that the alpha thalassaemia could be any of the genotypes such as, -alpha/alpha alpha, -alpha/-alpha, --/alpha alpha and alpha alpha/alpha alpha cs. Both heterozygotes and homozygotes for Hb CS were identified.

Fetal Blood↗
PubMed1990

Effect of in utero exposure to hexachlorocyclohexane on the developing immune system of mice.

Gestational exposure to 10 and 100 mg/kg body weight (m.b.w.) hexachlorocyclohexane throughout the gestation period was done to Swiss albino mice. HCH (alpha, beta and gamma isomers) residue analysis in pups showed a higher contamination in the lymphoid organs (Spleen, Thymus and Kidney) than liver in dose dependent manner. Immune functions of the offsprings of these dams along with the offsprings of vehicle treated or untreated control dams were assessed using selected parameters of both the cellular and humoral immune responses. The delayed hypersensitivity (DTH) response to sheep erythrocytes (SRBC) was significantly higher (p less than 0.01) in pups of the dams exposed to 10 mg/kg b.w. HCH and significantly impaired in pups of the dams exposed to 100 mg/kg m.b.w. HCH as compared to controls. Mitogenic responsiveness of the spleen cells in response to Concanavalin A (Con A) and Lipopolysaccharide (LPS) was almost two fold and eight fold higher respectively and antibody response to SRBC, as measured by plaque forming cells (PFC) assay was two fold higher (p less than 0.001) in pups exposed to 10 mg/kg HCH. However, 100 mg/kg m.b.w. HCH did not affect either mitogenic response or PFC response of the pups. The results, therefore, suggest that lower dose of HCH is capable of modulating the development and function of developing immune system possibly by modulating the functional organization of the T-cell populations.

Animals↗
PubMed1986

Cell surface antigens in squamous cell carcinoma of the oral cavity.

The ABH isoantigen was investigated in 80 patients with squamous cell carcinoma of the oral cavity and in their 46 affected lymph nodes. Isoantigen deletion shows a characteristic pattern of benign to malignant transformation of oral cancer. Total loss of isoantigen was found in anaplastic tumours, in metastatic lymph nodes and in the majority of advanced stage tumours. Total loss of isoantigen in metastatic lymph nodes indicates a frequent discharge of isoantigen-negative metastatic cells from the primary tumours to the lymph nodes and the regional organs. It seems that with the recent techniques a prospective observation of ABH isoantigen added to other pathological and clinical findings could be of prognostic significance in patients with squamous cell carcinoma of the oral cavity.

ABO Blood-Group System↗
PubMed1986

In vivo and in vitro observation of cellular immune parameters in squamous cell carcinoma of the oral cavity and its correlation with tumor load and prognosis.

In vivo and in vitro observations of cellular immune response in 70 patients with squamous cell cancer of the oral cavity and in 40 age-matched normal controls, were made using delayed hypersensitivity responses to DNCB, PPD, and Candida albicans extract (Dermatophytin 'O'), absolute lymphocyte counts, absolute T-cell numbers, and PHA-induced lymphocyte blastogenesis reactions as parameters. The results were correlated with clinical stage, tumor size, lymph node involvement, tumor differentiation, lymphoreticular responses, and outcome during a one-year follow-up period. A significant degree of impairment of both in vivo and in vitro parameters was found in oral cancer patients compared to normal control. The impairment was more prominent in advanced stages. Lymph node involvement was associated with impaired dermal hypersensitivity to recall antigens as well as a reduced T-cell population and blastogenic response. Only delayed hypersensitivity response to DNCB, PPD, and Candida showed a correlation with histologic features such as tumor differentiation and lymphoreticular response. Although absolute lymphocyte counts and T-cell population were reduced in the primary stage of the disease, the functional capacity of isolated lymphocytes to undergo blast formation was retained. PHA-induced lymphocyte blastogenesis showed a significant impairment only when the tumor was well established and disseminated beyond its local confines. Delayed hypersensitivity responses to DNCB, higher T-cell counts, and blastogenic indices were associated with recurrence-free survival. Immunologic parameters provide prognostic information beyond the clinical stage of the disease. Therefore, it seems that a multiparametric in vivo and in vitro observation of cellular immune response may be useful as an indicator of clinical course and prognosis of patients with squamous cell cancer of the oral cavity.

Aged↗
PubMed1985

Immune status in advanced upper gastrointestinal cancers.

Thirty-eight cases of advanced upper gastrointestinal cancer were assessed for their immune status prior to any form of therapy. Cell-mediated immunity, as tested by absolute lymphocyte count, T-cell count and delayed cutaneous hypersensitivity reactions to purified protein derivative and phytohemagglutinin showed severe depression. Immunoglobulins A and M were elevated, while immunoglobulin G reduced. No correlation could be established between the immune status and the site of cancer or its extent, the performance status of the patients, or their response to chemotherapy.

Adult↗
PubMed1985

A multiparametric observation of immune competence in breast cancer and its correlation with tumour load and prognosis.

A multiparametric observation of cellular immune status by delayed hypersensitivity response to primary and recall antigens, absolute lymphocyte counts, T-cells counts, lymphocyte stimulation to PHA and serum immunoglobulin levels (IgG, IgM, IgA) was done in 60 patients of breast cancer and 40 age-matched normal controls. The findings were correlated with clinical stage, tumour size, lymphnode involvement, distant metastases, tumour differentiation, lymphoreticular response and tumour recurrence within one year of follow-up period. Delayed hypersensitivity response to DNCB, PPD and Candida was significantly impaired (P = less than .001) in breast cancer patients as compared to normal controls. DNCB and candida response showed a gradual decrease with increasing clinical stage and PPD response was impaired in the advanced stage (Stage III and IV). Patients with well-differentiated tumour were more anergic than those with poorly differentiated tumour. Delayed hypersensitivity response to both primary and recall antigen showed a good correlation with tumour recurrence. Patients who had early recurrence or progressive disease were more anergic to all the three antigens. Absolute lymphocyte counts, absolute T-cells and E-rosette were significantly reduced in breast cancer patients as compared to normal controls and further correlated with clinical stage. Absolute T-cells and E-rosettes were lower in patients with lymphnode involvement, and distant metastases as compared to those with localized tumour. Absence of lymphoreticular response was related with impaired T-cell population. Absolute T-cell counts and E-rosettes further correlated with prognosis of the patients being significantly impaired in patients with early recurrence or with progressive disease (P = less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Intensive combination chemotherapy for cancer of the oral cavity.

Thirty advanced cases of cancer of the oral cavity were treated by intensive combination chemotherapy using bleomycin, methotrexate, 5-fluorouracil, cyclophosphamide, and Oncovin administered over a period of 48 hours. Bleomycin was given as a continuous infusion and Oncovin was administered six hours prior to the administration of other drugs. A clinical response was obtained in 73.3% of the cases, a complete response in 33.3%, and a partial response in 40%. The toxicity was within acceptable limits.

Adult↗