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Biomedical subjects

N A Khan

Publications and source records attributed to N A Khan.

At least 19 recordsLinked to original sources

Modulation of adipokines and cytokines in gestational diabetes and macrosomia.

CONTEXT/OBJECTIVE: Not much is known about the implication of adipokines and different cytokines in gestational diabetes mellitus (GDM) and macrosomia. The purpose of this study was to assess the profile of these hormones and cytokines in macrosomic babies, born to gestational diabetic women. DESIGN/SUBJECTS: A total of 59 women (age, 19-42 yr) suffering from GDM with their macrosomic babies (4.35 +/- 0.06 kg) and 60 healthy age-matched pregnant women and their newborns (3.22 +/- 0.08 kg) were selected. METHODS: Serum adipokines (adiponectin and leptin) were quantified using an obesity-related multiple ELISA microarray kit. The concentrations of serum cytokines were determined by ELISA. RESULTS: Serum adiponectin levels were decreased, whereas the concentrations of leptin, inflammatory cytokines, such as IL-6 and TNF-alpha, were significantly increased in gestational diabetic mothers compared with control women. The levels of these adipocytokines were diminished in macrosomic babies in comparison with their age-matched control newborns. Serum concentrations of T helper type 1 (Th1) cytokines (IL-2 and interferon-gamma) were decreased, whereas IL-10 levels were significantly enhanced in gestational diabetic mothers compared with control women. Macrosomic children exhibited high levels of Th1 cytokines and low levels of IL-10 compared with control infants. Serum IL-4 levels were not altered between gestational diabetic mothers and control mothers or the macrosomic babies and newborn control babies. CONCLUSIONS: GDM is linked to the down-regulation of adiponectin along with Th1 cytokines and up-regulation of leptin and inflammatory cytokines. Macrosomia was associated with the up-regulation of Th1 cytokines and the down-regulation of the obesity-related agents (IL-6 and TNF-alpha, leptin, and adiponectin).

Adiponectin↗

The 2006 Canadian Hypertension Education Program recommendations for the management of hypertension: Part II - Therapy.

OBJECTIVE: To provide updated, evidence-based recommendations for the management of hypertension in adults. OPTIONS AND OUTCOMES: For lifestyle and pharmacological interventions, evidence from randomized, controlled trials and systematic reviews of trials was preferentially reviewed. Changes in cardiovascular morbidity and mortality were the primary outcomes of interest. For lifestyle interventions, blood pressure (BP) lowering was accepted as a primary outcome given the lack of long-term morbidity/mortality data in this field. For treatment of patients with kidney disease, the development of proteinuria or worsening of kidney function was also accepted as a clinically relevant primary outcome. EVIDENCE: MEDLINE searches were conducted from November 2004 to October 2005 to update the 2005 recommendations. In addition, reference lists were scanned and experts were contacted to identify additional published studies. All relevant articles were reviewed and appraised independently by content and methodological experts using prespecified levels of evidence. RECOMMENDATIONS: Lifestyle modifications to prevent and/or treat hypertension include the following: perform 30 min to 60 min of aerobic exercise four to seven days per week; maintain a healthy body weight (body mass index of 18.5 kg/m2 to 24.9 kg/m2) and waist circumference (less than 102 cm for men and less than 88 cm for women); limit alcohol consumption to no more than 14 standard drinks per week in men or nine standard drinks per week in women; follow a diet that is reduced in saturated fat and cholesterol and that emphasizes fruits, vegetables and low-fat dairy products; restrict salt intake; and consider stress management in selected individuals. Treatment thresholds and targets should take into account each individual's global atherosclerotic risk, target organ damage and comorbid conditions. BP should be lowered to less than 140/90 mmHg in all patients, and to less than 130/80 mmHg in those with diabetes mellitus or chronic kidney disease (regardless of the degree of proteinuria). Most adults with hypertension require more than one agent to achieve these target BPs. For adults without compelling indications for other agents, initial therapy should include thiazide diuretics. Other agents appropriate for first-line therapy for diastolic hypertension with or without systolic hypertension include beta-blockers (in those younger than 60 years), angiotensin-converting enzyme (ACE) inhibitors (in nonblack patients), long-acting calcium channel blockers or angiotensin receptor antagonists. Other agents for first-line therapy for isolated systolic hypertension include long-acting dihydropyridine calcium channel blockers or angiotensin receptor antagonists. Certain comorbid conditions provide compelling indications for first-line use of other agents: in patients with angina, recent myocardial infarction or heart failure, beta-blockers and ACE inhibitors are recommended as first-line therapy; in patients with diabetes mellitus, ACE inhibitors or angiotensin receptor antagonists (or in patients without albuminuria, thiazides or dihydropyridine calcium channel blockers) are appropriate first-line therapies; and in patients with nondiabetic chronic kidney disease, ACE inhibitors are recommended. All hypertensive patients should have their fasting lipids screened, and those with dyslipidemia should be treated using the thresholds, targets and agents recommended by the Canadian Hypertension Education Program Working Group on the management of dyslipidemia and the prevention of cardiovascular disease. Selected patients with hypertension, but without dyslipidemia, should also receive statin therapy and/or acetylsalicylic acid therapy. VALIDATION: All recommendations were graded according to strength of the evidence and voted on by the 45 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations reported here achieved at least 95% consensus. These guidelines will continue to be updated annually.

Advisory Committees↗

N-3 fatty acids modulate antioxidant status in diabetic rats and their macrosomic offspring.

OBJECTIVE: We investigated the role of dietary n-3 polyunsaturated fatty acids (n-3 PUFA) in the modulation of total antioxidant status in streptozotocin (STZ)-induced diabetic rats and their macrosomic offspring. DESIGN: Female wistar rats, fed on control diet or n-3 PUFA diet, were rendered diabetic by administration of five mild doses of STZ on day 5 and were killed on days 12 and 21 of gestation. The macrosomic (MAC) pups were killed at the age of 60 and 90 days. MEASUREMENTS: Lipid peroxidation was measured as the concentrations of plasma thiobarbituric acid reactive substances (TBARS), and the total antioxidant status was determined by measuring (i) plasma oxygen radical absorbance capacity (ORAC), (ii) plasma vitamin A, E and C concentrations, and (iii) antioxidant enzymes activities in erythrocytes. The plasma lipid concentrations and fatty acid composition were also determined. RESULTS: Diabetes increased plasma triglyceride and cholesterol concentrations, whereas macrosomia was associated with enhanced plasma cholesterol and triglyceride levels, which diminished by feeding n-3 PUFA diet. N-3 PUFA diet also reduced increased plasma TBARS and corrected the decreased ORAC values in diabetic rats and their macrosomic offspring. EPAX diet increased the diminished vitamin A levels in diabetic mothers and vitamin C concentrations in macrosomic pups. Also, this diet improved the decreased erythrocyte superoxide dismutase and glutathione peroxidase activities in diabetic and macrosomic animals. CONCLUSION: Diabetes and macrosomia were associated with altered lipid metabolism, antioxidant enzyme activities and vitamin concentrations. N-3 PUFA diet improved hyperlipidemia and restored antioxidant status in diabetic dams and MAC offspring.

Animals↗

Comparative study of coronary collaterals in diabetic and nondiabetic patients by angiography.

Myocardial ischaemia is known to be significantly related to the development of coronary collaterals, but there are considerable variations in their formation. The nature of this variability is not well understood. Likewise it remains unclear whether diabetes mellitus. DM has any effect on coronary collaterals. The aim of this study was to evaluate the effect of diabetes mellitus on coronary collaterals. This prospective case- control study was done from January to December 2000 in patients undergoing coronary angiography in National Institute of Cardiovascular Diseases (NICVD), Dhaka, who fulfilled the inclusion criteria of having < or = 75% stenosis in at least one coronary artery. The patients with diabetes having CAD without other modifiable major risk factors (hypertension, smoking, dyslipidaemia) were constituted case study group (n=36) and nondiabetic patients having CAD with those risk factors were constituted control group (n=50). Coronary collaterals were graded according to Rentrope scoring system and the collateral score was calculated by summing the Rentrope number of every patient. There was no statistical difference between patients with and without diabetes in clinical characteristics. The mean number of diseased vessel in DM group 2.6+/-0.6 was higher than that in nondiabetic patients (2.1+/-0.8, P>.05). The mean collateral score was 0.5+/-0.6 in DM group and 1.2+/-1.0 in nondiabetic group. These findings suggest that coronary collateral development is significantly poorer in diabetic than on diabetic patients.

Case-Control Studies↗

Antioxidant status in alcohol-related diabetes mellitus in Beninese subjects.

In the present study, we investigated the antioxidant status in diabetes mellitus, related or not to alcohol consumption. A total of 38 type 1, 48 type 2 and 42 alcohol-related diabetic patients were selected. Total antioxidant status was assessed through the oxygen radical absorbance capacity of the plasma and the determination of enzymatic and non-enzymatic antioxidant molecules. Serum triglycerides, total cholesterol and HDL-cholesterol concentrations were determined and the lipid peroxydation was evaluated by measuring thiobarbituric acid reactive substances (TBARS) assay. Plasma total antioxidant capacity was more decreased in alcohol-related diabetes than that in type 1 and type 2 diabetes, regardless of the complications (retinopathy and renal failure). Plasma vitamin E concentrations were significantly decreased whereas those of vitamin C increased in all of the diabetic patients compared to the controls, irrespective to the complications. In addition, superoxide dismutase and glutathione peroxidase activities were reduced in all the patients (type 1, type 2 and alcohol-related), irrespective to the complications. Glutathione reductase activity was diminished in type 1 and alcohol-related, but not in type 2, diabetic patients. Glutathione (GSH) concentrations significantly decreased in all diabetic patients with a significant decrease in alcohol-related diabetic patients. Excessive alcohol consumption appears as an oxidative aggravating factor in diabetes mellitus. Besides, alcohol-related diabetes highly resembles to type 1 diabetes as far as the antioxidant parameters are concerned.

Adult↗

Dissection of systems, cell populations and molecules.

This paper summarizes studies on antibody formation in the bone marrow and the suppressive effects of intravenous immunization with allogeneic blood cells on T-cell function in mice. The latter studies were extended by employing the limiting dilution culture system developed in Ivan Lefkovits' laboratory and implemented in collaboration with Lucien Aarden. Thereby, the functional data were complemented with frequencies of alloantigen-activated helper (Th) and suppressor T cells after intravenous alloimmunization. These results led the Rotterdam group to studies on the prevention of rejection of the foetal 'allograft'. Th cells are central in foetal allograft rejection and pregnancy success. Characteristic for human pregnancy is the production of the glycoprotein chorionic gonadotropin (hCG) hormone. The in vivo liberated peptide fragments originating from nicking of the sequence MTRVLQGVLPALPQ in the beta-chain of hCG were considered for their immunoregulating capacity related to pregnancy success. These peptides - prepared synthetically - (MTR, MTRV, LQG, LQGV, VLPALP and others) indeed showed a remarkable spectrum of biological effects (e.g. modulation of angiogenesis, inhibition of septic shock syndrome, prevention of diabetes and reduction of ischaemia-reperfusion damage). The paper interprets and generalizes these findings and projects them into various research directions, especially towards the proteomics framework studies built up in Ivan Lefkovits' laboratory in the nineties. During the time period, when Ivan spent a mini-sabbatical in Rotterdam (months after closing down the BII) more detailed discussions were intiated. This paper is meant to keep the discussions between the involved research groups going on.

Animals↗

Ultrasonographic determination of amniotic fluid volume in normal pregnancy.

Ultrasonographic assessment of amniotic fluid has important implications because documentation of abnormalities of amniotic fluid volume may provide valuable information to enhance fetal health assessment. But in our country no study was conducted to establish normal values of amniotic fluid volume. So, this study was designed to find out normal values of amniotic fluid volume at various stages of gestation. The study was conducted in the department of Radiology and Imaging, BIRDEM in collaboration with the department of Obstetrics and Gynaecology, BIRDEM from 1(st) July, 2001 to 30(th) June, 2002. One hundred and twenty patients of normal pregnancy between 15 to 38 weeks' gestation were scanned by ultrasonography and their amniotic fluid volume was measured. For each gestational age between 15 and 38 weeks, 5 patients were recruited, and only one examination was done per pregnancy. Currently, the three semi-quantitative methods of assessing amniotic fluid volume include the amniotic fluid index (AFI), single deepest pocket (SDP) and two diameter pocket (TDP). Amniotic fluid volume of the study population was measured by the three methods. The values were plotted against each week in tabulated form. Thus the normal range of amniotic fluid volume in three methods (AFI, SDP, TDP) across gestational age in normal pregnancies was established. The mean value of amniotic fluid volume in AFI, SDP and TDP were 13.224 cm, 4.679 cm and 19.252 cm(2) respectively. AFI and SDP showed amniotic fluid volume increased with increasing gestational age up to early third trimester, but volume decreased thereafter. The prevalence of false positive result for oligohydramnios was 0.83% for AFI, 0% for SDP and 23% for TDP. The prevalence of false positive result for hydramnios was 1.66% for AFI, 0.83% for SDP and 0% for TDP. Thus the normal values of amniotic fluid volume for each of the three ultrasonographic techniques in the perspective of our country were obtained from the study. As the study was conducted with a limited number of patients, further study may be carried out with a large number of observations to reevaluate the results of the study.

Adult↗

Effect of Aralia cachemirica Decne root extracts on blood glucose level in normal and glucose loaded rats.

An aqueous and alcoholic extract of the roots of Aralia cachemirica (Araliaceae) were evaluated for hypoglycemic activity in normal fasted and glucose induced hyperglycemic rats. The aqueous and alcoholic extracts at a dose of 250 mg/kg showed statistically significant (p < 0.01) hypoglycemic activity in glucose loaded animals however no effect was observed in normal fasted rats.

Animals↗

An evaluation of the effects of exogenous ethephon, an ethylene releasing compound, on photosynthesis of mustard (Brassica juncea) cultivars that differ in photosynthetic capacity.

BACKGROUND: The stimulatory effect of CO2 on ethylene evolution in plants is known, but the extent to which ethylene controls photosynthesis is not clear. Studies on the effects of ethylene on CO2 metabolism have shown conflicting results. Increase or inhibition of photosynthesis by ethylene has been reported. To understand the physiological processes responsible for ethylene-mediated changes in photosynthesis, stomatal and mesophyll effects on photosynthesis and ethylene biosynthesis in response to ethephon treatment in mustard (Brassica juncea) cultivars differing in photosynthetic capacity were studied. RESULTS: The effects of ethephon on photosynthetic rate (PN), stomatal conductance (gS), carbonic anhydrase (CA) activity, 1-aminocyclopropane carboxylic acid synthase (ACS) activity and ethylene evolution were similar in both the cultivars. Increasing ethephon concentration up to 1.5 mM increased PN, gS and CA maximally, whereas 3.0 mM ethephon proved inhibitory. ACS activity and ethylene evolution increased with increasing concentrations of ethephon. The corresponding changes in gs and CA activity suggest that the changes in photosynthesis in response to ethephon were triggered by altered stomatal and mesophyll processes. Stomatal conductance changed in parallel with changes in mesophyll photosynthetic properties. In both the cultivars ACS activity and ethylene increased up to 3.0 mM ethephon, but 1.5 mM ethephon caused maximum effects on photosynthetic parameters. CONCLUSION: These results suggest that ethephon affects foliar gas exchange responses. The changes in photosynthesis in response to ethephon were due to stomatal and mesophyll effects. The changes in gS were a response maintaining stable intercellular CO2 concentration (Ci) under the given treatment in both the cultivars. Also, the high photosynthetic capacity cultivar, Varuna responded less to ethephon than the low photosynthetic capacity cultivar, RH30. The photosynthetic capacity of RH30 increased with the increase in ethylene evolution due to 1.5 mM ethephon application.

Carbon Dioxide↗

Diuretic and nephroprotective effect of Jawarish Zarooni Sada--a polyherbal unani formulation.

A number of drugs, both single and compound preparations are used widely in Tibb-e-Unani (Unani medicine) in the management of renal diseases. But such drugs mostly, have not been investigated for their described effects. Jawarish Zarooni Sada (JZS) is one such polyherbal preparation containing 15 ingredients, mainly described to be diuretic and nephroprotective. Therefore, in the present study ethanol and water extracts of JZS (300 mg each) were investigated for diuretic activity by measuring the total urine output over a period of 6h. Sodium and potassium level in urine sample was also estimated. Nephroprotective activity of JZS against gentamicin-induced nephrotoxicity was investigated by administering JZS along with high dose of gentamicin (40 mg/kg) and elevation of serum urea and serum creatinine was taken as the index of nephrotoxicity. JZS showed significant diuretic and nephroprotective effect.

Animals↗

Kinetic spectrophotometric method for the determination of silymarin in pharmaceutical formulations using potassium permanganate as oxidant.

A new simple and sensitive kinetic spectrophotometric method for the determination of silymarin in pure form and in pharmaceutical formulations is described. The method is based on the oxidation of the drug with potassium permanganate at pH 7.0 +/- 0.2. The reaction is followed spectrophotometrically by measuring the decrease in the absorbance at 530 nm. The calibration graph is linear in the range of 18-50 microg x m(-1). The method has been successfully applied to the determination of silymarin in pharmaceutical formulations. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.

Algorithms↗

Impaired oxidant/antioxidant status and LDL-fatty acid composition are associated with increased susceptibility to peroxidation of LDL in diabetic patients.

This study was carried out to determine the relationships between oxidant/antioxidant status, in vitro LDL oxidizability and LDL-fatty acid composition in diabetes mellitus. Plasma total antioxidant capacity (oxygen radical absorbance capacity, ORAC) and LDL-cholesteryl ester fatty acids were investigated in type 1 and type 2 diabetic subjects with and without complications. The degree of LDL oxidation was determined by the measurement of hydroperoxide levels before and after in vitro peroxidative stress with CuSO4. ORAC values were decreased in diabetic subjects who showed high basal hydroperoxide levels. Oxidizability of LDL in these subjects was higher than in control subjects and it was unrelated to LDL-fatty acid composition. However, in type 2 diabetic subjects with complications, alterations in LDL-fatty acid composition were associated with their enhanced oxidative susceptibility. LDL-fatty acid alterations might be an additional factor that influences LDL oxidizability especially in type 2 diabetes. In conclusion, diabetes mellitus is associated with enhanced oxidative stress and defective antioxidant/oxidant balance regardless the type of diabetes and presence of complications.

Adult↗

Further delineation of Hennekam syndrome.

We report four children from four inbred Arab families with varying manifestations of Hennekam syndrome and additional features that have not been previously reported. These include abnormalities of the middle ear, anomalous pulmonary venous drainage, interrupted inferior vena cava, polysplenia, crossed renal ectopia, median position of the liver and multiple cavernous haemangiomas. In addition, in one case lymphoedema was absent and oedema due to hypoproteinaemia appeared at 6 years of age. Since anomalies of the veins and the consequent developmental abnormalities of the lymphatics might lead to alterations in the fluid balance of the embryo, we hypothesize that altered fluid dynamics due to defective vascular and lymphatic development might disrupt critical events in craniofacial morphogenesis resulting in Hennekam syndrome.

Abnormalities, Multiple↗

Antioxidant status and levels of different vitamins determined by high performance liquid chromatography in diabetic subjects with multiple complications.

Plasma vitamin A, C and E levels and erythrocyte antioxidant enzyme activities were investigated in type I and type II diabetic subjects with and without complications, i.e., hypertension, coronary artery disease and renal failure. Reverse phase HPLC was used to quantify vitamin A and E levels. We observed that the vitamin C levels were not significantly different between control and diabetic subjects. However, vitamin A and E levels were significantly lower in type I and type II diabetic subjects compared to controls. Superoxide dismutase (SOD) activity was significantly lower in type II, but not in type I, diabetic patients compared to controls. Interestingly, glutathione reductase and peroxidase activities were diminished in type I, but not in type II, diabetic subjects as compared to controls. Catalase activity was lower in both types of diabetic patients in comparison with their respective controls. Altogether these results suggest that diabetes mellitus may be associated with altered antioxidant status regardless to various complications.

Adult↗

An unusual cause of vesical stone: a migrant intrauterine device.

Intrauterine contraceptives devices have been in use for many years. Although perforation of the uterus by an intrauterine device is not uncommon, intravesical migration with secondary stone formation is a rare complication. We report on a 32-year-old woman in whom an intrauterine contraceptive device (Copper T) migrated from her uterus into the bladder. She had lower urinary tract symptoms for nearly 2 years but sought no treatment. The onset of hematuria and fear of cancer prompted her to seek treatment. On investigation, a vesical stone was discovered that had formed on a copper T contraceptive device. It was removed via suprapubic cystostomy. In any woman in whom an intrauterine device is fitted and who presents with lower urinary tract symptoms, the possibility of intravesical migration of the device should be included in the differential diagnosis.

Adult↗

Staged revascularization in critically ill patients with coronary artery disease.

BACKGROUND: Critically ill patients undergoing bypass surgery experience a higher mortality and morbidity. HYPOTHESIS: The study was undertaken to evaluate the efficacy and value of percutaneous transluminal coronary angioplasty (PTCA) as a bridge to coronary artery bypass graft surgery (CABG) in high-risk patients with refractory unstable angina or cardiogenic shock. METHODS: We present 11 seriously unstable patients with severe multivessel coronary artery disease undergoing culprit vessel PTCA. Angioplasty was performed not as a definitive procedure but rather as a bridge to surgical revascularization. All the patients had sustained at least one myocardial infarction prior to catheterization, all had refractory unstable angina, eight patients had only a single patent coronary artery, and five patients were in cardiogenic shock. RESULTS: Following PTCA, all patients enjoyed a stable in-hospital period. One patient died 12 weeks after successful PTCA while awaiting second CABG. Seven patients subsequently underwent CABG and are doing well. The remaining three patients were also advised to undergo CABG, but elected to continue medical management. CONCLUSIONS: Coronary angioplasty of the culprit vessel may play a role as a bridge to surgery in critically ill patients.

Aged↗

Acanthamoeba can be differentiated by the polymerase chain reaction and simple plating assays.

Acanthamoeba are opportunistic pathogens with invasive and noninvasive species. For clinical purposes it is important to differentiate potentially pathogenic from nonpathogenic isolates. For the rapid and sensitive identification of Acanthamoeba at the genus level, we used a polymerase chain reaction (PCR)-based method which detected as few as five cells. Further, we tested nine isolates of Acanthamoeba for their ability to produce cytopathic effects (CPE) on corneal epithelial cells. On the basis of the results, Acanthamoeba were divided into pathogenic or nonpathogenic groups. However, because CPE assays are not available to every diagnostic laboratory, we developed a simple plating assay based on osmotolerance which correlated well with the CPE assays. Pathogenic Acanthamoeba showed growth on higher osmolarity (agar plates containing one molar mannitol), while growth of nonpathogens was inhibited on these plates. In conclusion, we have developed methods for the rapid identification and differentiation of Acanthamoeba.

Acanthamoeba↗

Pathogenicity, morphology, and differentiation of Acanthamoeba.

Acanthamoeba keratitis is sight threatening corneal infection caused by pathogenic Acanthamoeba. Previous studies have shown the genotypic differences between pathogenic and non-pathogenic species/strains of Acanthamoeba. In this study, we examined the morphological differences between pathogenic and non-pathogenic species/strains using scanning electron microscopy. Pathogenic Acanthamoeba exhibited higher number of acanthopodia (structures associated with the binding of amoeba to the target cells) as compared to non-pathogens. In addition, interactions of amoeba with the corneal epithelial cells were studied. Only pathogenic amoeba exhibited adhesion to epithelial cells. Further results indicated that phagocytosis occurs in the pathogenic amoeba by the formation of amoebastome (characteristic of amoeba phagocyte). This study showed that Acanthamoeba phagocytosis may be both an efficient means of obtaining nutrients for the amoeba and a significant factor in the pathogenesis of Acanthamoeba infections.

Acanthamoeba↗