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Biomedical subjects

B C Koner

Publications and source records attributed to B C Koner.

24 records · Page 2Linked to original sources
PubMed1997

Modulation of gamma glutamyl transpeptidase activity in lymphoid system by organochlorine pesticides in rats.

Effects of 1,1,1,-trichloro-2,2-bis (p-chlorophenyl) ethane (DDT) and lindane were studied on gamma glutamyl transpeptidase (GGT) activity in different tissues of the lymphoid system in rats. DDT (100 or 200 ppm) and lindane (30 or 80 ppm) exposure for 8 weeks suppressed the GGT activity in a dose dependent manner in thymus and macrophage. In spleen, significant decrease in the enzyme activity was observed at higher exposure (200 ppm DDT or 80 ppm lindane) levels. Lindane suppressed GGT activity at both 30 or 80 ppm dose levels, while DDT reduced the GGT activity at 200 ppm but not at 100 ppm exposure in lymphocyte. The study indicates the possibility of using GGT as an effective and consistent biochemical marker for immunotoxicity of xenobiotics and other environmental stressors.

Animals↗
PubMed1996

Immunotoxicity of pesticides: perspectives and trends.

In recent years, great concern has been expressed about genotoxic potential of pesticide chemicals. These toxic chemicals have become an integral part of the ecosystem and the human health effects of these agents are yet to be satisfactorily defined. The objectives of this review is to examine the sources of information available; evaluation of experimental protocols employed for assessment of immunological effects; and to study specific cellular and molecular locus which could be responsible for impaired immune responsiveness. It is emphasized that threshold level for the pesticide effect below which no effect would be seen, depends on the animal species, the method of testing for immune responses and type of antigen used. A comparative assessment of immune responses using different antigens is, therefore, an important aspect of pesticide immunotoxicity. In view of widespread use, distribution and stability of some of these compounds in the environment, pesticide exposure may play a greater role in suspected fragile immune system, and may result in altered disease susceptibility. An understanding of these risks depends, to a great extent, upon cellular and molecular events underlying pesticide-induced immune alterations in experimental animals. It is, therefore, proposed that pesticide chemicals may influence humoral immunity while having no detectable effect on cell-mediated immunity (CMI); immune dysfunction is related to dose and duration of pesticide exposure; a single assay of immune function may not be appropriate to detect pesticide-induced immune dysfunction; since many immune responses are genetically controlled, alterations in responsiveness to one challenge in a given animal model may not hold true in second one; although it has been established that pesticide chemicals can alter immune function, the mechanisms of action have yet to be determined. This paper also reviews the effects of pesticide on lymphocyte function and suggests that lymphocyte dysfunction may be an integral part of pesticide-induced immunosuppression and presents an approach which may serve to delineate the possible mechanisms of action. It is quite clear that pesticide-induced immunomodulation endangers humans and animals. This hazard should, therefore, not to be underestimated in evaluation of toxicity of these chemicals. However, additional research is needed in basic mechanism of immunotoxicity and identification of susceptibility factors which predispose to these reactions.

Animals↗
PubMed1996

Influence of subchronic exposure to lindane on humoral immunity in mice.

Lindane suppressed both primary and secondary antibody responses to sheep red blood cell (SRBC) in albino mice, the effects being more pronounced on the secondary than the primary response. However, a longer duration of pesticide exposure induced similar degrees of immunosuppression on both responses. The sequential study of plaque forming cells (PFC) kinetics revealed that suppression of plaque formation not only occurred at peak days but also on pre and post peak days, and there was no delay in peak antibody formation. Moreover, reduction in the primary PFC was not associated with decrease in the antibody response to SRBC. The results indicate that lindane suppresses both primary and secondary humoral immune responses in a time and dose dependent manner, and suggest a threshold susceptibility to exposure.

Animals↗
PubMedDate not supplied

Diagnostic peritoneal lavage (DPL)--is it useful decision making process for management of the equivocal acute abdomen?

Patients with a traumatic or non-traumatic acute abdominal conditions often have equivocal findings regarding the need for surgery. Ultrasound and computed tomography, though useful, have limitations and not always available in peripheral hospitals. Diagnostic peritoneal lavage (DPL) was investigated as an aid to decision-making in such patients. After preliminary X-ray and ultrasound, DPL was performed in 50 patients with an equivocal acute abdomen (18 trauma, 32 non-trauma). It was found that overall sensitivity, specificity, accuracy, and positive and negative predictive values were high for patients with trauma. All the above parameters except specificity and negative predictive value (NPV) were also found to be high for the non-trauma group. DPL was found to be a bedside investigation, which helped in taking the decision to operate on patients with both traumatic and non-traumatic acute abdomen.

Abdomen, Acute↗
PubMedDate not supplied

Effect on gallbladder function subsequent to truncal vagotomy and gastrojejunostomy for chronic duodenal ulcer.

The effect of truncal vagotomy on gallbladder function and on the incidence of lithogenesis has remained controversial. A prospective and retrospective investigational study was undertaken to evaluate the effect of truncal vagotomy and gastrojejunostomy on gallbladder function. The study included a total of 76 patients and 77 controls. In Group I (Prospective group), 32 consecutive patients with chronic duodenal ulcer and gastric outlet obstruction undergoing truncal vagotomy and gastrojejunostomy were included. Group II included 25 age and gender matched controls (prospective group). Group III included 44 patients who had undergone truncal vagotomy and gastrojejunostomy 3 years or more prior to presentation (Retrospective group) and Group IV included 52 age and gender matched controls for the retrospective group. The patients in the prospective groups were followed up for a period of 1 year. An alkaline tide test was done in the prospective and retrospective group to assess for the completeness of vagotomy. Gallbladder contractile response to fatty meal and the presence of stones and sludge were noted in all the four groups by ultrasonography. There were 30 patients in the prospective group and 40 in the retrospective group after excluding patients with incomplete vagotomy. On ultrasound examination, there was no significant difference in the gallbladder volume and contractility of the study group when compared with the controls. Gallbladder sludge was found in 16 to 25% of patients in the prospective group (group I) during follow up, where as similar finding was documented in 8% of the matched control (group II (P>0.1). However, in the retrospective (group III) 10% (4 out of 40) had calculi and 20% of patients demonstrated sludge which was significantly higher when compared with the controls (p = 0.001). Truncal vagotomy and gastrojejunostomy did not affect gallbladder contractility, but it might predispose to the formation of sludge and subsequent calculi in a proportion of patients in long term.

Adolescent↗