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Biomedical subjects

B Singh

Publications and source records attributed to B Singh.

At least 91 records · Page 5Linked to original sources

Anti-inflammatory activity of 'TAF' an active fraction from the plant Barleria prionitis Linn.

'TAF' fraction from the methanol-water extract of Barleria prionitis Linn. was evaluated for anti-inflammatory and anti-arthritic activities against different acute and chronic animal test models. It exhibited significant anti-inflammatory activity against different inflammagens like carrageenan, histamine and dextran. The anti-inflammatory activity in adrenalectomised rats was maintained showing that the effect of fraction 'TAF' is not activated by the pituitary-adrenal axis. Significant anti-arthritic activity was observed in adjuvant-induced polyarthritis test in rats. 'TAF' also showed inhibition of vascular permeability and leucocytes migration in vivo into the site of inflammatory insult.Ibuprofen (Cadilla India Ltd., Mumbai) was used as a standard reference drug. The oral (p.o.) LD(50) was more than 3000mg/kg, with no signs of abnormalities or any mortality observed for 15 days after single-dose drug administration. The intraperitoneal (i.p.) LD(50) was found to be 2530mg/kg (+/-87mg/kg S.E.) [Proceedings of Society of Experimental Biological Medicine 57 (1944) 261].

Acanthaceae↗

Cholecystectomy in a predominantly African population before and after the advent of the laparoscopic technique.

OBJECTIVE: There is a paucity of information on gallbladder disease in an African population. We, therefore, conducted a study to compare the immediate pre-laparoscopic era with the laparoscopic period in the predominantly African population at the King Edward VIII Hospital. MATERIAL AND METHODS: Data from a retrospective analysis of 144 patients undergoing open cholecystectomy (OC) between January 1990 and December 1992 were compared with a prospective analysis of 156 patients who underwent laparoscopic cholecystectomy (LC) between February 1992 and December 1994. Demographic data, presentation, operative management and outcome were the main factors analysed. RESULTS: Eighty-two per cent were Black African and the rest of Indian origin. Endoscopic retrograde cholangiopancreatography (ERCP) confirmed ductal stones in 11 patients in the OC and nine patients in the LC group. Endoscopic duct clearance was achieved in three and nine patients, respectively. Non biliary complications were rare. There were two major duct injuries in the OC group and one cystic duct leak in the LC group. The high conversion rate of 17.9% attests to the severity of their chronic disease making safe dissection in Calot's triangle problematic. The mortality in patients undergoing OC was 1 (0.07%) and 0% for LC. In South Africa, the hospital prevalence of calculous disease in African patients is increasing. However, cholecystectomy may be safely performed. CONCLUSION: The absence of any mortality and any major duct injury in the LC group allude to the safety of this procedure when appropriately applied to this population group.

Adolescent↗

Intracellular expression of Mycobacterium tuberculosis-specific 10-kDa antigen down-regulates macrophage B7.1 expression and nitric oxide release.

To explore the role of the 10-kDa Mycobacterium tuberculosis-specific secreted antigen (MTSA-10 or CFP-10) in modulation of macrophage function, J774 macrophages were transfected stably with DNA encoding MTSA-10. Compared to normal or mock-transfected controls, MTSA-10-expressing macrophages had markedly lower levels of co-stimulatory molecule B7.1 on their surface, while the expression of B7.2 and ICAM-1 was not affected. MTSA-transfected cells also produced significantly less microbicidal free radical nitric oxide (NO) upon stimulation with interferon (IFN)-gamma, lipopolysaccharide or M. tuberculosis cell lysate. Western blot analysis revealed the absence of tyrosine-phosphorylated protein slightly larger than 112 kDa in MTSA-transfected macrophages. Moreover, the treatment of control J774 cells with protein tyrosine kinase inhibitor genistein completely mimicked the effects of transfection with MTSA-10, selectively down-regulating NO and B7.1, but not B7.2 or ICAM-1 expression. The observed MTSA-10-mediated block of B7.1 expression and NO release might contribute to the suppression of antimycobacterial response in tuberculosis.

Animals↗

Anti-inflammatory activity of shikonin derivatives from Arnebia hispidissima.

Arnebia hispidissima ethanolic extract, after chromatography, yielded a number of shikonin derivatives, which were identified as arnebin-5, arnebin-6, teracryl shikonin, arnebinone and acetyl shikonin. All these compounds were firstly reported from this plant species and evaluated to the anti-inflammatory activity of ethanolic extract and isolated shikonin derivatives, models with carrageenan-induced paw edema and complete Freund's adjuvant (CFA)-induced chronic arthritis in rats were conducted. The observed results indicated that pre-treatment with arnebinone significantly inhibited the carrageenan-induced paw edema and also suppressed the development of chronic arthritis induced by CFA.

Animals↗

Morphology and comparative anatomy of circulus arteriosus cerebri in mammals.

The normal configuration of the arterial pattern at the base of the brain in rhesus monkeys, dogs, sheep, goats and rabbits is described. The length and diameter of all vessels of the circulus arteriosus cerebri are measured. Variations are compared in relation to that of the typical pattern present in humans. In rhesus monkeys, dogs and rabbits, the circle of Willis is almost similar to that in human beings except that in these animals, (i) the anterior cerebral arteries join each other to form a single median vessel; (ii) in dogs, rabbits, goats and sheep the anterior cerebellar artery is a branch of posterior cerebral artery, and (iii) in goats and sheep, a considerable length of the internal carotid artery contributes to the formation of circulus arteriosus while the posterior cerebral artery arises from the posterior communicating artery.

Animals↗

Radiographic (ILO) readings predict arterial oxygen desaturation during exercise in subjects with asbestosis.

BACKGROUND: Exercise impairment is common in subjects with asbestosis. Arterial oxygen desaturation during exercise is an important contributor to exercise limitation. The International Labour Office (ILO) classification of plain chest radiographs correlates with resting pulmonary function, but its value in predicting abnormal ventilatory responses to exercise, including desaturation, has not been explored. AIMS: To determine in subjects with asbestosis (1) if radiographic profusion scores and the extent of small irregular shadows on plain chest radiographs correlate with resting lung function and abnormal ventilatory responses to exercise; and (2) if radiographic scores add value to resting lung function tests in predicting abnormal ventilatory responses to exercise. METHODS: Thirty eight male subjects with asbestosis were included. Plain chest radiographs were read according to the ILO classification independently by three observers. All subjects underwent assessment of lung function and an incremental exercise test. RESULTS: Profusion scores and number of affected zones correlated significantly with the percentage predicted values of single breath diffusing capacity (DLCO), forced vital capacity (FVC), and total lung capacity (TLC). Arterial oxygen desaturation occurred in 29% of the subjects. The severity of desaturation correlated significantly with profusion and the number of affected zones. The combined use of number of affected zones, FEV(1)/FVC ratio and DLCO predicted desaturation during exercise with an explained variance of 41%. VO(2)max was significantly related only to DLCO but was not predicted by the ILO score. CONCLUSION: Arterial oxygen desaturation correlated with the profusion and extent of parenchymal abnormality on chest radiographs. The addition of morphological indices to physiological measurements is valuable for predicting oxygen desaturation during exercise but not for VO(2)max. Refinement of the radiographic scoring system and the addition of more sophisticated imaging techniques may further improve the predictive power.

Aged↗

Mixed signals from Kerala's improving health status.

It can be said that health policy is about creating the conditions to free a population from disease and impairment, and so prolong the quality of life for all. If this is its purpose, then the practice of public health policy in the Indian state of Kerala presents a conundrum for health promotion analysts. On the one hand, Kerala has had remarkable success in reducing its infant mortality rates to around one-third of the Indian average, but on the other, its morbidity rates have risen to impose an economic cost more than three times the national level. This paper sets out to explain this apparent contradiction in outcomes, serving both to provide a review of Kerala's health status and as an illustrative guide for the interpretation of the effects of health policy in some other developing areas. While the essential health data for Kerala might imply an unsatisfactory future, the authors argue that the rapid improvements that have occurred simultaneously in public education are more likely to explain an increase in the effective reporting of disease conditions, thus suggesting a more optimistic scenario for future practice that can lead to a sustained improvement in health care.

Health Promotion↗

Localization of integrin alpha(v)beta3 and vascular endothelial growth factor receptor-2 (KDR/Flk-1) in cutaneous and oral melanomas of dog.

Melanomas are common neoplasms of dogs and arise from pigment-producing cells called melanocytes or melanoblasts. Melanomas of skin are often easily cured by surgical excision, but those of oral mucosa are aggressive, metastasize to the regional lymph nodes and lungs, and respond poorly to conventional therapy. Tumor growth is sustained by proliferation of microvessels via a process called angiogenesis. Integrin alpha(v)beta3 is expressed in proliferating but not in quiescent microvessels suggesting a role in angiogenesis. Vascular endothelial growth factor (VEGF) manifests its mitogenic and angiogenic effects mainly via VEGF receptor-2 (VEGFR-2/Flk-1). We conducted this immunocytochemical study to investigate the expression of integrin alpha(v)beta3 and VEGFR-2 in archival and fresh samples from cases of canine melanomas. Results show that integrin alpha(v)beta3 was expressed in 72% and 88% of cutaneous and oral melanomas, respectively, and the expression was restricted to and immediately around the melanocytes and endothelial cells. VEGFR-2 staining of selected cases of melanoma revealed that its expression overlapped with the alpha(v)beta3 integrin. Dual immuno-gold electron microscopy confirmed co-localization of integrin alpha(v)beta3 and VEGFR-2 in melanocytes and endothelial cells. These data demonstrate expression and co-localization of integrin alpha(v)beta3 and VEGFR-2 in cutaneous and oral melanomas of dogs.

Animals↗

Inferior lumbar triangle hernia: case report.

A patient with a spontaneously acquired hernia along the inferior lumbar triangle commonly referred to as lumbar triangle of Petit is presented. This was confirmed on CT scan and successfully treated surgically. A review of the literature relevant to this condition is presented. It is likely that with advances in imaging techniques and a wider clinical usage of these investigative modalities there will be further recognition of this uncommon condition.

Hernia, Abdominal↗

The pathogenesis of membranoproliferative glomerulonephritis in KwaZulu-Natal, South Africa is unrelated to hepatitis C virus infection.

Idiopathic membranoproliferative glomerulonephritis (MPGN) is a well-defined clinicopathological entity with a poor prognosis, with 50% of patients progressing to end stage renal disease (ESRD) within 10 years. It was reported in about 36% of adult Black patients with nephrotic syndrome in our center previously [Seedat et al. 1988]. Hepatitis C virus (HCV) infection has been shown to be associated with cryoglobulinemic as well as non-cryoglobulinemic (or idiopathic glomerulonephritis). The aim of this study was to determine whether an association exists between HCV infection and idiopathic MPGN in a population with a relatively high prevalence of MPGN. We studied adult patients referred with glomerular disease over a two-year period, 104 patients had primary glomerulonephritis. All 23 (22%) patients with idiopathic MPGN were enrolled, as well as 32 age-matched patients presenting with other primary glomerular diseases. We examined serum from all 55 patients for evidence of HCV antibodies and HCV RNA. None of the 55 patients showed evidence of HCV infection. Chronic renal failure was present in 82.6% of the patients with idiopathic MPGN and it was advanced in 52,2%, who either were dialysis-requiring at presentation or progressed to ESRD soon thereafter; 30.4% had moderate chronic renal failure, while only 17.4% had normal renal function. HCV infection is not associated with idiopathic MPGN in our patients. Idiopathic MPGN remains an idiopathic disease, possibly with a poor prognosis in our population.

Adolescent↗

Why we use the donor left kidney in live related transplantation.

UNLABELLED: In addition to the superior graft survival afforded by live related transplantation, this option has assumed an important role in the management of endstage renal failure in centres confronted with a scarcity of cadaveric kidneys. In pursuing this option, it is imperative that the donor has minimal morbidity. An ongoing dilemma is which side the kidney should be harvested from. This study reviews the anatomical basis for selecting the left kidney and the impact on outcome for patient and donor. A database comprising cadaveric and clinical subsets was analysed. The total sample size analysed was 1 244 kidney pairs (305 cadaveric; 939 clinical (61 live related left kidney transplants harvested by the extraperitoneal approach)). RESULTS: Additional renal arteries (ARAs): Right first, second = 18.6%, 4.7%; left first, second = 27.6%, 4.4%. Additional renal veins (ARV): Right first, second = 26%, 3.3%; left first only = 2.6%. Length of renal vein (cm): Right 2.4 +/- 0.7, left 5.9 +/- 1.5. Other venous variations encountered were on the left side only (renal collar 0.3%, retro-aortic vein 0.5%). In the live related transplant series 24.6% ARAs were encountered (first 19.7%, second 4.9%). The postoperative course and outcome of both donor and recipient were not associated with increased morbidity. While greater length of the left renal vein (LRV) afforded easier technical manipulation, it is interesting to note that its length is shorter than that reported in the literature. ARVs are infrequent on the left and when encountered the smaller calibre vessel may be ligated with impunity due to rich intrarenal anastomosis. In selecting the donor kidney the surgeon has to balance the prospect of fewer ARAs on the right against the benefit of a longer LRV. The solution to this dilemma can only arise from a randomised clinical study. In our practice, consistent use of the left kidney has not affected clinical outcome.

Cadaver↗

Regulation of type 1 diabetes by a self-MHC class II peptide: role of transforming growth factor beta (TGF-beta).

The present study was undertaken to analyze the regulatory T cells generated in response to class I derived self-I-A beta(g7) (54-76) peptide. It was observed T cells from young unprimed type 1 diabetes (T1D) prone NOD mice did not respond to self-I-A beta(g7) (54-76) peptide although T cells from primed young NOD mice showed a strong response. T cells from young unprimed BALB/c mice responded to self-I-A beta(d) (62-78) peptide. However, a breakdown of tolerance to these peptides was observed with age in both the strains. Culture supernatant from I-A beta(g7) (54-76) peptide-primed cells secreted large amounts of TGF-beta and inhibited T cell responses in allogeneic-MLR. Further, I-A beta(g7) (54-76) peptide specific T cell lines from young (I-A.Y) and diabetic (I-A.D) NOD mice were established. I-A.Y secreted IL-4, TGF-beta and IL-10 while I-A.D T cell line secreted IL-10 and IFN-gamma. We found that I-A.D T cell line induced diabetes when transferred in NOD/SCID mice but I-A.Y T cell line did not induce disease. These results show that immunization of NOD mice with I-A beta(g7) (54-76) peptide at a younger age induces a regulatory T cell response suggesting that correcting the defects in immunoregulatory mechanisms using self-MHC peptides may be one of the approaches to prevent autoimmune diseases like T1D.

Animals↗

Lead induced oxidative stress: beneficial effects of Kombucha tea.

OBJECTIVE: To evaluate the effect of oral administration of Kombucha tea (K-tea) on lead induced oxidative stress. METHODS: Sprague Dawley rats were administered 1 mL of 3.8% lead acetate solution daily alone or in combination with K-tea orally for 45 d, and the antioxidant status and lipid peroxidation were evaluated. RESULTS: Oral administration of lead acetate to rats enhanced lipid peroxidation and release of creatine phosphokinase and decreased levels of reduced glutathione (GSH) and antioxidant enzymes (superoxide dismutase, SOD and glutathione peroxidase, GPx). Lead treatment did not alter humoral immunity, but inhibited DTH response when compared to the control. Lead administration also increased DNA fragmentation in liver. Oral administration of Kombucha tea to rats exposed to lead decreased lipid peroxidation and DNA damage with a concomitant increase in the reduced glutathione level and GPx activity. Kombucha tea supplementation relieved the lead induced immunosuppression to appreciable levels. CONCLUSION: The results suggest that K-tea has potent antioxidant and immunomodulating properties.

Administration, Oral↗