T. Naicker - Academia.edu (original) (raw)
Papers by T. Naicker
Hypertension in Pregnancy, 2016
Placenta, 2014
Hypertensive disorders of pregnancy are the commonest direct cause of maternal deaths in South Af... more Hypertensive disorders of pregnancy are the commonest direct cause of maternal deaths in South Africa, 83% being attributed to pre-eclampsia. Elevated placental sFlt-1 levels are linked with angiogenic disruption and subsequent pre-eclampsia development. The impact of HIV infection on pre-eclampsia is controversial. Its effect on angiogenic imbalance in both normotensive and pre-eclamptic pregnancies remains unknown. We examined the immunolocalisation of both membrane bound and soluble forms of Flt-1, within placentae of HIV negative and positive normotensive and pre-eclamptic pregnancies at term using immunohistochemistry and immuno-electron microscopy. Strong Flt-1 and sFlt-1 immunoreactivity was observed within endothelial, syncytio and cytotrophoblast cells. Subcellularly, gold particles were localised predominantly within the endoplasmic reticulum and mitochondria and occurring free within the cytoplasm. There was no significant effect of HIV on Flt-1 and sFlt-1 immunoexpressio...
Folia morphologica, 2012
The present study was undertaken to evaluate the possible reno-protective effect of Ficus exasper... more The present study was undertaken to evaluate the possible reno-protective effect of Ficus exasperata leaf aqueous extract (FEE) in a rat experimental paradigm of diabetes mellitus. Forty Wistar rats (weighing 200-230 g) were divided into four (A, B, C, and D) groups, each group consisting of 10 rats. Group A rats served as 'control' animals and received citrate buffer (pH 6.3) solution in quantities equivalent to intraperitoneally-administered volumes of streptozotocin (STZ) and FEE. Diabetes mellitus was induced in Groups B and C rats by intraperitoneal injections of STZ (75 mg/kg). Group C rats were additionally treated with FEE (100 mg/kg/day, p.o.) 4 weeks post STZ injections, for 4 consecutive weeks. Group D rats received FEE (100 mg/kg/day p.o.) only for 4 weeks. Post-euthanisation, kidney tissues were excised for histopathological evaluation and processed for light microscopy. Plasma malondialdehyde and tissue nitric oxide were determined. Serum creatinine, blood urea...
Israel journal of medical sciences, 1996
Ventricular arrhythmia has been postulated as a possible cause of death in young black children w... more Ventricular arrhythmia has been postulated as a possible cause of death in young black children who abuse volatile substances, primarily benzine and certain glues that contain n-hexane. A series of protocols were designed to determine the effect of n-hexane on myocardial function and morphology in male laboratory rats. In the first protocol, experiments were designed to study the effect of n-hexane in initiating ventricular fibrillation and in modifying myocardial magnesium and potassium levels. The results showed that the thresholds for ventricular fibrillation and myocardial magnesium and potassium levels were reduced compared to control values. In the second protocol, n-hexane-treated rats were supplemented with intragastric administration of magnesium and potassium salts. The outcome of the experiments indicated that although the myocardial magnesium and potassium levels were corrected, the threshold for ventricular fibrillation remained low compared to control values. In the th...
The Central African journal of medicine, 1995
This study was designed to test the hypothesis that hydrochlorothiazide a diuretic used to treat ... more This study was designed to test the hypothesis that hydrochlorothiazide a diuretic used to treat hypertension depletes body zinc and thereby cause sexual dysfunction. Serum zinc and sexual dysfunction were measured in 39 middle aged hypertensive men who had been taking hydrochlorothiazide in average daily doses of between 25 and 50 mg daily for at least six months, and a control group of 27 unmedicated middle aged normotensive men. The medicated group had a higher incidence of sexual dysfunction (56 pc) as compared to 11 pc in the control group. The use of hydrochlorothiazide did affect serum zinc levels significantly in 20 patients. Sexual dysfunction occurred more often in older and overweight patients (p < 0.004). Three of the normotensive men experienced sexual dysfunction probably related to old age. Twenty two of the 39 on hydrochlorothiazide and experiencing sexual dysfunction were divided into two groups of 11 patients. Bloods were taken from the 27 normotensive and 22 hy...
International journal of experimental pathology, 1993
Specimens from the left ventricular myocardium of 10 rats that had been exposed to subcutaneously... more Specimens from the left ventricular myocardium of 10 rats that had been exposed to subcutaneously administered hexane for 30 days were morphometrically and morphologically examined. Other than the presence of occasional necrotic fibres in hexane-treated animals, there was little difference in the histological appearance of myofibres in control or experimental specimens. There was a slight reduction in the average diameter of cardiac myofibres after exposure to hexane. Pathological ultrastructural changes of the myofibres were noted in the experimental and not in the control groups. Mitochondrial oedema and necrosis and myofilament disorganization and dissolution were significant changes noted in the experimental group. These pathological changes suggest that hexane, a constituent of glue and benzine, is cardiotoxic.
Israel journal of medical sciences, 1993
Plasma endothelin-1 activity was measured by radioimmunoassay in 24 normotensive non-pregnant wom... more Plasma endothelin-1 activity was measured by radioimmunoassay in 24 normotensive non-pregnant women and in 24 normotensive pregnant, 24-aproteinuric hypertensive and 24 pre-eclamptic women. Endothelin-1 activity was increased in the pre-eclamptic group (2.7 +/- 06 pg/ml) compared to the normotensive non-pregnant (1.0 +/- 0.8 pg/ml; P < 0.0001), normotensive pregnant (1.2 +/- 0.4 pg/ml; P < 0.0001) group and the aproteinuric hypertensive group (1.4 +/- 0.7 pg/ml; P < 0.0001). There was no difference in endothelin-1 activity between the normotensive non-pregnant and normotensive pregnant group (1.0 +/- 0.8 vs. 1.2 +/- 0.4 pg/ml; P = 0.3). However, there was a difference between the aproteinuric hypertensive group (1.4 +/- 0.7 pg/ml) and both the normotensive nonpregnant (1.0 +/- 0.8 pg/ml; P < 0.01) and the normotensive pregnant group (1.2 +/- 0.4 pg/ml; P < 0.06). The birth weight in the pre-eclamptic group (2.48 +/- 0.61 kg) was significantly lower than that of the normotensive pregnant group (2.85 +/- 0.33 kg; P < 0.001) and the aproteinuric hypertensive group (2.99 +/- 0.46 kg; P < 0.001). In addition, there was no difference in birth weight between the normotensive pregnant group and aproteinuric hypertensive group (2.85 +/- 0.33 vs. 2.99 +/- 0.46 kg; P = 0.3). A significant Pearson's correlation of plasma endothelin-l versus birth weight in the pre-eclamptic group was obtained (r = 0.64; P < 0.0001). Endothelin-1 activity is increased with pre-eclampsia in black African women with pre-eclampsia. The results of our study also suggests an ethnic difference in plasma endothelin-1 activity when compared to result of studies carried out in Caucasian women with hypertensive disorders of pregnancy.
Immunopharmacology, 1997
Increased renal production of vasodilator mediators like kinins would counteract the vasospasm of... more Increased renal production of vasodilator mediators like kinins would counteract the vasospasm of pre-eclampsia. This Ž . study examines the cellular localisation of tissue kallikrein TK , the potent kinin forming enzyme within the nephron of patients with early onset pre-eclampsia. Using the peroxidase-antiperoxidase immunoenzyme complex, TK was immunolocalised in the principal cells of the distal connecting tubule and the cortical collecting duct cells of the distal nephron of control tissue. Moderate reactivity was observed in the epithelial cells lining the Bowmans capsule. In early onset pre-eclampsia, TK was additionally localised in the proximal tubule cells, however, the intensity of reactivity was reduced when compared to that of the distal tubule cells. In patients with hypertension of pregnancy, the occurrence of TK in the proximal tubule suggests either gene induction or emiocytosis of TK.
Pregnancy Hypertension: An International Journal of Women's Cardiovascular Health, 2012
ABSTRACT
African Journal of Biomedical Research, 2010
Exposure to carbon tetrachloride (CCl 4 ) induces acute and chronic renal injuries as well as oxi... more Exposure to carbon tetrachloride (CCl 4 ) induces acute and chronic renal injuries as well as oxidative stress in rats. The aim of this study was to evaluate the effect of exogenous melatonin (MEL) treatment on CCl 4 -induced oxidative stress and nephrotoxicity in rats using histopathological and biochemical parameters. Serum creatinine, blood urea nitrogen (BUN), nitrite and albumin concentrations were measured for the evaluation of renal function. Antioxidant status in the kidney tissue was estimated by determining the activities of superoxide dismustase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and glutathione-S-transferase (GST) as well as thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH) levels. For histopathological evaluation, kidney of all rats were excised and processed for light microscopy. CCl 4 caused elevated level of TBARS and marked depletion of renal endogenous antioxidant enzymes. Furthermore, severe deterioration of renal function was observed in CCl 4 -treated rats as assessed by increased serum creatinine, BUN levels and decreased creatinine and urea clearance as compared with the control rats. MEL treatment positively ameliorated the alterations in these biochemical variables in the CCl 4 + MEL-treated rats. MEL markedly reduced elevated TBARS and nitrite, significantly attenuated renal dysfunction, increased the levels of antioxidant enzymes. Kidney sections of CCl 4 -treated group showed, changes in microanatomy. In contrast, these deleterious histopathological alterations resulting from CCl 4 nephrotoxin were absent after MEL treatment in CCl 4 + MEL group of rats. In conclusion, our results demonstrated that MEL through its antioxidant activity effectively ameliorated CCl 4induced nephrotoxicity. (Afr. J. Biomed. Res. 10: 153 -164)
Immunopharmacology, 1997
Literature survey, thus far, has shown a decrease in the excretion of urinary tissue kallikrein T... more Literature survey, thus far, has shown a decrease in the excretion of urinary tissue kallikrein TK in transplant patients with a further reduction of the enzyme during episodes of acute rejection. The study aims were to compare, at cellular and subcellular levels, the localisation of tissue kallikrein in biopsies of the transplant kidney to autopsy derived normal renal tissue. Renal biopsies from eighteen transplant patients with deteriorating renal function were obtained. Immunolabelling for tissue kallikrein, using a polyclonal goat anti-TK, antibody raised against recombinant TK, was performed following routine enzymatic, immunofluorescence and electron microscopic techniques. In normal kidney tissue, TK was immunolocalised in the distal connecting tubules and collecting ducts. By comparison the renal transplant tissue showed a reduction in the intensity of label, but maintained the sites of localisation. In the sections examined by electron microscopy, although TK was confined mainly at the luminal side of the cell, some label was noted along the basolateral membranes. In the transplant kidneys, there was a reduction in the overall number of gold particles counted, which correlated with the decreased intensity observed on immunocytochemistry. In addition, there was a shift to a basolateral orientation of the immunolabel. Acute rejection is characterised by oedema, tubulitis and vasculitis. Destruction of the tubule cells and leakage of TK into the interstitial tissue space and the resultant effect of the formed kinins on renal capillary vasculature could explain the observed renal parenchymal oedema and transplant rejection. 0162-3109r97r$17.00 Copyright q 1997 Elsevier Science B.V. All rights reserved.
Tuberculosis, 2013
s u m m a r y Tuberculosis (TB) is mainly a disease of the lungs, but Mycobacterium tuberculosis ... more s u m m a r y Tuberculosis (TB) is mainly a disease of the lungs, but Mycobacterium tuberculosis (Mtb) can establish infection in virtually any organ in the body. Rising rates of extrapulmonary (EP) TB have been largely associated with the HIV epidemic, as patients co-infected with HIV show a four-fold higher risk of EPTB. Spinal TB (Pott's Disease), one of the most debilitating extrapulmonary forms of disease, is difficult to diagnose and can cause deformity and/or neurological deficits. This study examined the histopathology and distribution of immune cells within spinal TB lesions and the impact of HIV on pathogenesis. The overall structure of the spinal granulomas resembled that seen in lung lesions from patients with pulmonary TB. Evidence of efficient macrophage activation and differentiation were detectable within organized structures in the spinal tissue, irrespective of HIV status. Interestingly, the granulomatous architecture and macroscopic features were similar in all samples examined, despite a reversal in the ratio of infiltrating CD4 to CD8 T cells in the lesions from HIV-infected patients. This study provides a foundation to understand the mechanism of tissue destruction and disease progression in Spinal TB, enabling the future development of novel therapeutic strategies and diagnostic approaches for this devastating disease.
Transplantation Proceedings, 2001
Nephron, 1997
This study morphometrically evaluates the glomerular anionic charge and examines the renal pathol... more This study morphometrically evaluates the glomerular anionic charge and examines the renal pathology in African women with early-onset pre-eclampsia. Polyethyleneimine-labelled anionic sites were decreased within the glomerular basement membrane in the early-onset pre-eclampsia group as compared with the control group (p < or = 0.02). A strong correlation (r = -0.76) was obtained between the number of anionic sites and the severity of proteinuria. Renal biopsy specimens revealed the coexistence of decreased glomerular charge with pathology of glomerular basement membrane, endothelial cells, foot processes, and mesangial cell proliferation. The loss of glomerular charge induces structural alterations of the glomerular filtration barrier and may be the mechanism responsible for proteinuria in early-onset pre-eclampsia.
Pharmacology & Therapeutics, 1997
Drugs used in the acute and long-term management of hypertension in pregnancy and the preeclampsi... more Drugs used in the acute and long-term management of hypertension in pregnancy and the preeclampsia-eclampsia syndrome have been reviewed and their therapeutic effects and maternal and fetal adverse effects have been considered. The review also focuses on recent developments in the areas of prevention and management of pre-eclampsia-eclampsia syndrome. Although a number of new drugs have emerged, as potentially useful in the management of hypertension in pregnancy and pre-eclampsia-eclampsia syndrome, some remain at the cornerstone of therapy; for example, methyldopa for long-term treatment of chronic hypertension, hydralazine or nifedipine for rapid reduction of severely elevated blood pressure, and magnesium sulphate for eclampsia. Some of these agents, especially the calcium antagonists, show promise in that their use is associated with fewer side effects. Safety for the fetus, however, has not been adequately evaluated yet. Neither aspirin nor calcium supplements appear to improve the outcome in pregnancy. Currently, the dilemma whether to treat hypertension in pregnancy and predeclampsia-eclampsia syndrome with old, established, cost-effective drugs or the promising newer drugs provides an interesting academic challenge.
British Journal of Plastic Surgery, 1995
The morphological appearance of longitudinally sectioned rat femoral arteries was determined in i... more The morphological appearance of longitudinally sectioned rat femoral arteries was determined in intact arteries and from 3 to 435 days after vessel division and anastomosis with either 9/O gauge nylon or polydioxanone (PDS) in 26 animals. The purpose of the study was to establish the mechanisms and compare the quality of healing after microarterial anastomosis and to determine whether PDS was degraded before sufficient anastomotic healing had taken place. The results revealed that there was no difference in the process of healing or quality of anastomosis with either suture material. From 3 to 21 days post anastomosis, there was a progressive separation of the ends of vessels within the developing scar. Anastomotic patency was established and maintained at first by an adventitial overgrowth of fibroblasts and undifferentiated adventitial cells and later by the growth of a smooth myocyte scar that stretched between the cut ends of the vessel and over the intima in the form of elongated circumferential plaques. The vessel was morphologically healed by the 21st day. The sutures served little or no purpose in maintaining anastomotic integrity after the 5th day, being situated in the scar forming between the separating vessel ends. PDS was present within the vessel wall up to 120 days post anastomosis and was certainly intact at the time of morphological healing, suggesting that this material is safe as a microvascular suture.
Journal of Pharmacy and Pharmacology, 1993
The isolated liver perfusion technique was used to study the effect of therapeutic doses of parac... more The isolated liver perfusion technique was used to study the effect of therapeutic doses of paracetamol on hepatic gluconeogenesis and bromosulphthalein clearance from the perfusate and biliary excretion of the dye in the rat. Six groups of rats were studied; those in the three experimental groups were given 0.02 g kg-1 paracetamol daily for ninety days. The livers of animals in the control group and in one of the experimental groups were perfused with a medium containing pyruvate. The animals in the second experimental and control group were perfused with a medium containing bromosulphthalein (10 mg/100 mL). The livers of the third experimental and control group were subjected to histological examination. The rate of glucose formation and glucose concentrations were decreased, while, lactate levels and lactate: pyruvate ratios were increased in paracetamol-treated rats. The mean concentration of bromosulphthalein in the perfusate and biliary excretion of the dye were decreased. Macro and micro vesicular fatty change was present in the livers of paracetamol-treated rats. This study demonstrates that chronic administration of therapeutic doses of paracetamol to rats adversely affects liver function, as evidenced by impaired gluconeogenesis and bromosulphthalein clearance from the perfusate, and excretion of the dye into the bile, and provides histological evidence of hepatic damage in rats.
Journal of Obstetrics & Gynaecology, 2001
Maternal plasma ET-1 levels and the immunolocalisation of ET1 in the fetal membranes of pre-eclam... more Maternal plasma ET-1 levels and the immunolocalisation of ET1 in the fetal membranes of pre-eclamptic primigravidae at &amp;amp;amp;gt;/=28 weeks, gestation were studied. The levels of maternal plasma ET1 and immunoreactive ET-1 were increased in pre-eclampsia. Immunoreactive ET-1 was localised in the amnion, chorion and decidua of normal pregnant women as well as those with preeclampsia-eclampsia. Intense labelling was observed in moderate pre-eclampsia (BP 140/90 - 170/110 mmHg) with very intense labelling in severe pre-eclampsia (BP &amp;amp;amp;gt;170/110 mmHg), especially in the amniotic epithelium, chorionic villi, maternal blood vessels, cytotrophoblasts and giant cells of the decidua. The increased ET-1 levels demonstrated in fetal membranes of pre-eclamptic women are probably produced in a paracrine and/or autocrine manner, contributing to the hypertension, vasospasm and fetal growth restriction characteristic of the syndrome. A larger study would be required to show significant change in endothelin production in pre-eclampsia.
Journal of Obstetrics & Gynaecology, 2002
ABSTRACT
Hypertension in Pregnancy, 2016
Placenta, 2014
Hypertensive disorders of pregnancy are the commonest direct cause of maternal deaths in South Af... more Hypertensive disorders of pregnancy are the commonest direct cause of maternal deaths in South Africa, 83% being attributed to pre-eclampsia. Elevated placental sFlt-1 levels are linked with angiogenic disruption and subsequent pre-eclampsia development. The impact of HIV infection on pre-eclampsia is controversial. Its effect on angiogenic imbalance in both normotensive and pre-eclamptic pregnancies remains unknown. We examined the immunolocalisation of both membrane bound and soluble forms of Flt-1, within placentae of HIV negative and positive normotensive and pre-eclamptic pregnancies at term using immunohistochemistry and immuno-electron microscopy. Strong Flt-1 and sFlt-1 immunoreactivity was observed within endothelial, syncytio and cytotrophoblast cells. Subcellularly, gold particles were localised predominantly within the endoplasmic reticulum and mitochondria and occurring free within the cytoplasm. There was no significant effect of HIV on Flt-1 and sFlt-1 immunoexpressio...
Folia morphologica, 2012
The present study was undertaken to evaluate the possible reno-protective effect of Ficus exasper... more The present study was undertaken to evaluate the possible reno-protective effect of Ficus exasperata leaf aqueous extract (FEE) in a rat experimental paradigm of diabetes mellitus. Forty Wistar rats (weighing 200-230 g) were divided into four (A, B, C, and D) groups, each group consisting of 10 rats. Group A rats served as 'control' animals and received citrate buffer (pH 6.3) solution in quantities equivalent to intraperitoneally-administered volumes of streptozotocin (STZ) and FEE. Diabetes mellitus was induced in Groups B and C rats by intraperitoneal injections of STZ (75 mg/kg). Group C rats were additionally treated with FEE (100 mg/kg/day, p.o.) 4 weeks post STZ injections, for 4 consecutive weeks. Group D rats received FEE (100 mg/kg/day p.o.) only for 4 weeks. Post-euthanisation, kidney tissues were excised for histopathological evaluation and processed for light microscopy. Plasma malondialdehyde and tissue nitric oxide were determined. Serum creatinine, blood urea...
Israel journal of medical sciences, 1996
Ventricular arrhythmia has been postulated as a possible cause of death in young black children w... more Ventricular arrhythmia has been postulated as a possible cause of death in young black children who abuse volatile substances, primarily benzine and certain glues that contain n-hexane. A series of protocols were designed to determine the effect of n-hexane on myocardial function and morphology in male laboratory rats. In the first protocol, experiments were designed to study the effect of n-hexane in initiating ventricular fibrillation and in modifying myocardial magnesium and potassium levels. The results showed that the thresholds for ventricular fibrillation and myocardial magnesium and potassium levels were reduced compared to control values. In the second protocol, n-hexane-treated rats were supplemented with intragastric administration of magnesium and potassium salts. The outcome of the experiments indicated that although the myocardial magnesium and potassium levels were corrected, the threshold for ventricular fibrillation remained low compared to control values. In the th...
The Central African journal of medicine, 1995
This study was designed to test the hypothesis that hydrochlorothiazide a diuretic used to treat ... more This study was designed to test the hypothesis that hydrochlorothiazide a diuretic used to treat hypertension depletes body zinc and thereby cause sexual dysfunction. Serum zinc and sexual dysfunction were measured in 39 middle aged hypertensive men who had been taking hydrochlorothiazide in average daily doses of between 25 and 50 mg daily for at least six months, and a control group of 27 unmedicated middle aged normotensive men. The medicated group had a higher incidence of sexual dysfunction (56 pc) as compared to 11 pc in the control group. The use of hydrochlorothiazide did affect serum zinc levels significantly in 20 patients. Sexual dysfunction occurred more often in older and overweight patients (p < 0.004). Three of the normotensive men experienced sexual dysfunction probably related to old age. Twenty two of the 39 on hydrochlorothiazide and experiencing sexual dysfunction were divided into two groups of 11 patients. Bloods were taken from the 27 normotensive and 22 hy...
International journal of experimental pathology, 1993
Specimens from the left ventricular myocardium of 10 rats that had been exposed to subcutaneously... more Specimens from the left ventricular myocardium of 10 rats that had been exposed to subcutaneously administered hexane for 30 days were morphometrically and morphologically examined. Other than the presence of occasional necrotic fibres in hexane-treated animals, there was little difference in the histological appearance of myofibres in control or experimental specimens. There was a slight reduction in the average diameter of cardiac myofibres after exposure to hexane. Pathological ultrastructural changes of the myofibres were noted in the experimental and not in the control groups. Mitochondrial oedema and necrosis and myofilament disorganization and dissolution were significant changes noted in the experimental group. These pathological changes suggest that hexane, a constituent of glue and benzine, is cardiotoxic.
Israel journal of medical sciences, 1993
Plasma endothelin-1 activity was measured by radioimmunoassay in 24 normotensive non-pregnant wom... more Plasma endothelin-1 activity was measured by radioimmunoassay in 24 normotensive non-pregnant women and in 24 normotensive pregnant, 24-aproteinuric hypertensive and 24 pre-eclamptic women. Endothelin-1 activity was increased in the pre-eclamptic group (2.7 +/- 06 pg/ml) compared to the normotensive non-pregnant (1.0 +/- 0.8 pg/ml; P < 0.0001), normotensive pregnant (1.2 +/- 0.4 pg/ml; P < 0.0001) group and the aproteinuric hypertensive group (1.4 +/- 0.7 pg/ml; P < 0.0001). There was no difference in endothelin-1 activity between the normotensive non-pregnant and normotensive pregnant group (1.0 +/- 0.8 vs. 1.2 +/- 0.4 pg/ml; P = 0.3). However, there was a difference between the aproteinuric hypertensive group (1.4 +/- 0.7 pg/ml) and both the normotensive nonpregnant (1.0 +/- 0.8 pg/ml; P < 0.01) and the normotensive pregnant group (1.2 +/- 0.4 pg/ml; P < 0.06). The birth weight in the pre-eclamptic group (2.48 +/- 0.61 kg) was significantly lower than that of the normotensive pregnant group (2.85 +/- 0.33 kg; P < 0.001) and the aproteinuric hypertensive group (2.99 +/- 0.46 kg; P < 0.001). In addition, there was no difference in birth weight between the normotensive pregnant group and aproteinuric hypertensive group (2.85 +/- 0.33 vs. 2.99 +/- 0.46 kg; P = 0.3). A significant Pearson's correlation of plasma endothelin-l versus birth weight in the pre-eclamptic group was obtained (r = 0.64; P < 0.0001). Endothelin-1 activity is increased with pre-eclampsia in black African women with pre-eclampsia. The results of our study also suggests an ethnic difference in plasma endothelin-1 activity when compared to result of studies carried out in Caucasian women with hypertensive disorders of pregnancy.
Immunopharmacology, 1997
Increased renal production of vasodilator mediators like kinins would counteract the vasospasm of... more Increased renal production of vasodilator mediators like kinins would counteract the vasospasm of pre-eclampsia. This Ž . study examines the cellular localisation of tissue kallikrein TK , the potent kinin forming enzyme within the nephron of patients with early onset pre-eclampsia. Using the peroxidase-antiperoxidase immunoenzyme complex, TK was immunolocalised in the principal cells of the distal connecting tubule and the cortical collecting duct cells of the distal nephron of control tissue. Moderate reactivity was observed in the epithelial cells lining the Bowmans capsule. In early onset pre-eclampsia, TK was additionally localised in the proximal tubule cells, however, the intensity of reactivity was reduced when compared to that of the distal tubule cells. In patients with hypertension of pregnancy, the occurrence of TK in the proximal tubule suggests either gene induction or emiocytosis of TK.
Pregnancy Hypertension: An International Journal of Women's Cardiovascular Health, 2012
ABSTRACT
African Journal of Biomedical Research, 2010
Exposure to carbon tetrachloride (CCl 4 ) induces acute and chronic renal injuries as well as oxi... more Exposure to carbon tetrachloride (CCl 4 ) induces acute and chronic renal injuries as well as oxidative stress in rats. The aim of this study was to evaluate the effect of exogenous melatonin (MEL) treatment on CCl 4 -induced oxidative stress and nephrotoxicity in rats using histopathological and biochemical parameters. Serum creatinine, blood urea nitrogen (BUN), nitrite and albumin concentrations were measured for the evaluation of renal function. Antioxidant status in the kidney tissue was estimated by determining the activities of superoxide dismustase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and glutathione-S-transferase (GST) as well as thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH) levels. For histopathological evaluation, kidney of all rats were excised and processed for light microscopy. CCl 4 caused elevated level of TBARS and marked depletion of renal endogenous antioxidant enzymes. Furthermore, severe deterioration of renal function was observed in CCl 4 -treated rats as assessed by increased serum creatinine, BUN levels and decreased creatinine and urea clearance as compared with the control rats. MEL treatment positively ameliorated the alterations in these biochemical variables in the CCl 4 + MEL-treated rats. MEL markedly reduced elevated TBARS and nitrite, significantly attenuated renal dysfunction, increased the levels of antioxidant enzymes. Kidney sections of CCl 4 -treated group showed, changes in microanatomy. In contrast, these deleterious histopathological alterations resulting from CCl 4 nephrotoxin were absent after MEL treatment in CCl 4 + MEL group of rats. In conclusion, our results demonstrated that MEL through its antioxidant activity effectively ameliorated CCl 4induced nephrotoxicity. (Afr. J. Biomed. Res. 10: 153 -164)
Immunopharmacology, 1997
Literature survey, thus far, has shown a decrease in the excretion of urinary tissue kallikrein T... more Literature survey, thus far, has shown a decrease in the excretion of urinary tissue kallikrein TK in transplant patients with a further reduction of the enzyme during episodes of acute rejection. The study aims were to compare, at cellular and subcellular levels, the localisation of tissue kallikrein in biopsies of the transplant kidney to autopsy derived normal renal tissue. Renal biopsies from eighteen transplant patients with deteriorating renal function were obtained. Immunolabelling for tissue kallikrein, using a polyclonal goat anti-TK, antibody raised against recombinant TK, was performed following routine enzymatic, immunofluorescence and electron microscopic techniques. In normal kidney tissue, TK was immunolocalised in the distal connecting tubules and collecting ducts. By comparison the renal transplant tissue showed a reduction in the intensity of label, but maintained the sites of localisation. In the sections examined by electron microscopy, although TK was confined mainly at the luminal side of the cell, some label was noted along the basolateral membranes. In the transplant kidneys, there was a reduction in the overall number of gold particles counted, which correlated with the decreased intensity observed on immunocytochemistry. In addition, there was a shift to a basolateral orientation of the immunolabel. Acute rejection is characterised by oedema, tubulitis and vasculitis. Destruction of the tubule cells and leakage of TK into the interstitial tissue space and the resultant effect of the formed kinins on renal capillary vasculature could explain the observed renal parenchymal oedema and transplant rejection. 0162-3109r97r$17.00 Copyright q 1997 Elsevier Science B.V. All rights reserved.
Tuberculosis, 2013
s u m m a r y Tuberculosis (TB) is mainly a disease of the lungs, but Mycobacterium tuberculosis ... more s u m m a r y Tuberculosis (TB) is mainly a disease of the lungs, but Mycobacterium tuberculosis (Mtb) can establish infection in virtually any organ in the body. Rising rates of extrapulmonary (EP) TB have been largely associated with the HIV epidemic, as patients co-infected with HIV show a four-fold higher risk of EPTB. Spinal TB (Pott's Disease), one of the most debilitating extrapulmonary forms of disease, is difficult to diagnose and can cause deformity and/or neurological deficits. This study examined the histopathology and distribution of immune cells within spinal TB lesions and the impact of HIV on pathogenesis. The overall structure of the spinal granulomas resembled that seen in lung lesions from patients with pulmonary TB. Evidence of efficient macrophage activation and differentiation were detectable within organized structures in the spinal tissue, irrespective of HIV status. Interestingly, the granulomatous architecture and macroscopic features were similar in all samples examined, despite a reversal in the ratio of infiltrating CD4 to CD8 T cells in the lesions from HIV-infected patients. This study provides a foundation to understand the mechanism of tissue destruction and disease progression in Spinal TB, enabling the future development of novel therapeutic strategies and diagnostic approaches for this devastating disease.
Transplantation Proceedings, 2001
Nephron, 1997
This study morphometrically evaluates the glomerular anionic charge and examines the renal pathol... more This study morphometrically evaluates the glomerular anionic charge and examines the renal pathology in African women with early-onset pre-eclampsia. Polyethyleneimine-labelled anionic sites were decreased within the glomerular basement membrane in the early-onset pre-eclampsia group as compared with the control group (p < or = 0.02). A strong correlation (r = -0.76) was obtained between the number of anionic sites and the severity of proteinuria. Renal biopsy specimens revealed the coexistence of decreased glomerular charge with pathology of glomerular basement membrane, endothelial cells, foot processes, and mesangial cell proliferation. The loss of glomerular charge induces structural alterations of the glomerular filtration barrier and may be the mechanism responsible for proteinuria in early-onset pre-eclampsia.
Pharmacology & Therapeutics, 1997
Drugs used in the acute and long-term management of hypertension in pregnancy and the preeclampsi... more Drugs used in the acute and long-term management of hypertension in pregnancy and the preeclampsia-eclampsia syndrome have been reviewed and their therapeutic effects and maternal and fetal adverse effects have been considered. The review also focuses on recent developments in the areas of prevention and management of pre-eclampsia-eclampsia syndrome. Although a number of new drugs have emerged, as potentially useful in the management of hypertension in pregnancy and pre-eclampsia-eclampsia syndrome, some remain at the cornerstone of therapy; for example, methyldopa for long-term treatment of chronic hypertension, hydralazine or nifedipine for rapid reduction of severely elevated blood pressure, and magnesium sulphate for eclampsia. Some of these agents, especially the calcium antagonists, show promise in that their use is associated with fewer side effects. Safety for the fetus, however, has not been adequately evaluated yet. Neither aspirin nor calcium supplements appear to improve the outcome in pregnancy. Currently, the dilemma whether to treat hypertension in pregnancy and predeclampsia-eclampsia syndrome with old, established, cost-effective drugs or the promising newer drugs provides an interesting academic challenge.
British Journal of Plastic Surgery, 1995
The morphological appearance of longitudinally sectioned rat femoral arteries was determined in i... more The morphological appearance of longitudinally sectioned rat femoral arteries was determined in intact arteries and from 3 to 435 days after vessel division and anastomosis with either 9/O gauge nylon or polydioxanone (PDS) in 26 animals. The purpose of the study was to establish the mechanisms and compare the quality of healing after microarterial anastomosis and to determine whether PDS was degraded before sufficient anastomotic healing had taken place. The results revealed that there was no difference in the process of healing or quality of anastomosis with either suture material. From 3 to 21 days post anastomosis, there was a progressive separation of the ends of vessels within the developing scar. Anastomotic patency was established and maintained at first by an adventitial overgrowth of fibroblasts and undifferentiated adventitial cells and later by the growth of a smooth myocyte scar that stretched between the cut ends of the vessel and over the intima in the form of elongated circumferential plaques. The vessel was morphologically healed by the 21st day. The sutures served little or no purpose in maintaining anastomotic integrity after the 5th day, being situated in the scar forming between the separating vessel ends. PDS was present within the vessel wall up to 120 days post anastomosis and was certainly intact at the time of morphological healing, suggesting that this material is safe as a microvascular suture.
Journal of Pharmacy and Pharmacology, 1993
The isolated liver perfusion technique was used to study the effect of therapeutic doses of parac... more The isolated liver perfusion technique was used to study the effect of therapeutic doses of paracetamol on hepatic gluconeogenesis and bromosulphthalein clearance from the perfusate and biliary excretion of the dye in the rat. Six groups of rats were studied; those in the three experimental groups were given 0.02 g kg-1 paracetamol daily for ninety days. The livers of animals in the control group and in one of the experimental groups were perfused with a medium containing pyruvate. The animals in the second experimental and control group were perfused with a medium containing bromosulphthalein (10 mg/100 mL). The livers of the third experimental and control group were subjected to histological examination. The rate of glucose formation and glucose concentrations were decreased, while, lactate levels and lactate: pyruvate ratios were increased in paracetamol-treated rats. The mean concentration of bromosulphthalein in the perfusate and biliary excretion of the dye were decreased. Macro and micro vesicular fatty change was present in the livers of paracetamol-treated rats. This study demonstrates that chronic administration of therapeutic doses of paracetamol to rats adversely affects liver function, as evidenced by impaired gluconeogenesis and bromosulphthalein clearance from the perfusate, and excretion of the dye into the bile, and provides histological evidence of hepatic damage in rats.
Journal of Obstetrics & Gynaecology, 2001
Maternal plasma ET-1 levels and the immunolocalisation of ET1 in the fetal membranes of pre-eclam... more Maternal plasma ET-1 levels and the immunolocalisation of ET1 in the fetal membranes of pre-eclamptic primigravidae at &amp;amp;amp;gt;/=28 weeks, gestation were studied. The levels of maternal plasma ET1 and immunoreactive ET-1 were increased in pre-eclampsia. Immunoreactive ET-1 was localised in the amnion, chorion and decidua of normal pregnant women as well as those with preeclampsia-eclampsia. Intense labelling was observed in moderate pre-eclampsia (BP 140/90 - 170/110 mmHg) with very intense labelling in severe pre-eclampsia (BP &amp;amp;amp;gt;170/110 mmHg), especially in the amniotic epithelium, chorionic villi, maternal blood vessels, cytotrophoblasts and giant cells of the decidua. The increased ET-1 levels demonstrated in fetal membranes of pre-eclamptic women are probably produced in a paracrine and/or autocrine manner, contributing to the hypertension, vasospasm and fetal growth restriction characteristic of the syndrome. A larger study would be required to show significant change in endothelin production in pre-eclampsia.
Journal of Obstetrics & Gynaecology, 2002
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