Short-term heart variability and oxidative stress in newly diagnosed essential hypertension

We sought to evaluate oxidative stress parameters like malondialdehyde, total antioxidant status, and time, frequency domain heart rate variability indices in newly diagnosed untreated hypertension. We also sought to study the correlation between heart rate variability and oxidative stress parameters in normotensive and newly diagnosed untreated essential hypertensives. Fourteen normotensive males and 36 newly diagnosed male hypertensives were enrolled for the study. Malondialdehyde, total antioxidant status, and heart rate variability in the frequency and time domain were studied in the hypertensive and normotensive group. Malondialdehyde was significantly higher in the hypertensive group, whereas total antioxidant status was significantly higher in the control group. SDNN, RR triangular index, RMSSD, log(10) low-frequency power, log (10) high-frequency power, log (10) total power, and heart rate variability during deep breathing test was significantly lower in hypertensive patients compared to normotensive controls. SDNN, RMSSD, high-frequency power, and high-frequency power normalized had significant negative correlation with malondialdehyde. Low-frequency power normalized positively correlated with malondialdehyde. Total antioxidant status had a significant negative correlation with blood pressure. The study gives further evidence for a decreased heart rate variability and elevated oxidative stress in hypertension.     

Oxidative stress varies with the mode of delivery in intrauterine growth retardation: association with Apgar score

OBJECTIVE: To assess if oxidative injury in intrauterine growth retarded and healthy newborns is affected by the mode of delivery and whether Apgar score as a marker of neonatal survival is dependent on lipid and protein oxidative injury assessed by measuring malondialdehyde and protein carbonylation. METHODS: 30 IUGR newborns, 15 born by normal vaginal delivery and 15 born by elective caesarean section, and 40 healthy control infants, 30 born by normal vaginal delivery and 10 born by elective caesarean section, were studied at birth. Cord blood was collected for determination of malondialdehyde and protein carbonylation. RESULTS: IUGR newborns had significantly elevated MDA and protein carbonylation than the control group. Apgar scores, both at 1 and 5 min, were significantly lower in the IUGR group. These were assessed by independent sample t test. Using one-way ANOVA we found that MDA and protein carbonyls levels were not statistically different in healthy control group and in IUGR subgroup born by caesarean section however they were significantly different in other groups. Linear regression analysis revealed that Apgar scores both at 1 min and 5 min were dependent on MDA in IUGR newborns. Apgar score was however not dependent on protein carbonylation in the same group. CONCLUSION: Apgar score in IUGR newborns is dependent on the extent of oxidative injury and elective caesarean section minimises the same.     

Insulin: a novel agent in the pathogenesis of prostate cancer

Prostate cancer, the most frequent non-cutaneous malignancy in aging men, is a growing medical problem, representing the second leading cause of male cancer deaths. Despite its high morbidity, the etiology of prostate cancer remains largely unknown. Several studies have documented hormonal imbalance, such as alteration in androgens and estrogens, obesity, family history and growth factors, as risk factors in the pathogenesis of prostate cancer. Insulin is a growth-promoting hormone that is reported to be involved in the pathogenesis of various malignancies, such as breast and bladder cancers. Insulin is known to increase cancer risk through its effect on cell proliferation, differentiation and apoptosis. In the last decade, converging evidence from epidemiological and clinical studies suggests that the insulin is involved in the tumorigenesis and neoplastic growth of the prostate. Several mechanisms have been suggested to explain the possible causal relationship between insulin and prostate cancer, such as the sympathoexcitatory effect of insulin, alteration of sex hormone metabolism, insulin-like growth factor pathway, signal transduction mechanism and dyslipidemia. The present paper reviews relevant existing studies related to the role of insulin in the pathogenesis of prostate carcinoma.     

Benign prostatic hyperplasia: dietary and metabolic risk factors

Benign prostatic hyperplasia (BPH) is the most common nonmalignant condition of the prostate occurring in ageing men. Even though BPH is a major public health problem, causing high morbidity and substantial worsening in men's quality of life, little is known about its risk factors. Several studies revealed that it is a multifactorial disease. Previous studies have documented family history, hormonal imbalance, and growth factors as etiological factors in the development of BPH. This review focuses on the dietary and metabolic risk factors including diabetes mellitus, hypertension, obesity, hyperinsulinemia, as well as dyslipidemia and their mechanisms in the pathogenesis of BPH.     

Relationship of raised serum total and protein bound sialic acid levels with hyperinsulinemia and indices of insulin sensitivity and insulin resistance in non-diabetic normotensive obese subjects

AimsObesity is known to be associated with cardiovascular disease and interaction between inflammation and insulin resistance is reported to enhance the cardiovascular risk in these subjects. The present study was designed to assess indices of insulin sensitivity, insulin resistance and sialic acid levels and their association in non-diabetic normotensives obese subjects.Materials and methodsThe present study was conducted in 30 obese male subjects and results were compared with 30 subjects with normal body weight. Insulin, total sialic acid and protein bound sialic acid were estimated in all the subjects. Insulin resistance was calculated by using Homeostatic Model Assessment-insulin resistance formula. Insulin sensitivity was assessed by quantitative insulin check index and insulin sensitivity index.ResultsInsulin resistance, serum total and protein bound sialic acid levels were significantly increased in obese cases as compared to non-obese controls. Total sialic acid showed significant positive correlation with HOMA-IR (p < 0.01), BMI (p < 0.01), waist and hip circumference (p < 0.01) and negative correlation with QUICKI (p < 0.01) and insulin sensitivity index (p = 0.018). There was no significant correlation between protein bound sialic acid and indices of insulin resistance and insulin sensitivity.ConclusionSialic acid levels are elevated in obese subjects and its association with insulin resistance and reduced insulin sensitivity may enhance the cardiovascular risk in these subjects.     

Protein extract of kenaf seed exhibits anticoagulant,antiplatelet and antioxidant activities

Objective:To explore the anticoagulant,antiplatelet and antioxidant activities of protein extract of kenaf seed(PEKS).Methods:Sodium dodecyl sulphate polyacrylamide gel electrophoresis and reverse-phase high-performance liquid chromatography techniques were employed for protein characterization.Antioxidant activity of PEKS was assessed using 1,1-diphenyl-2-picrylhydrazyl(DPPH)assay.The protective effect of PEKS on sodium nitrite(NaNO2)induced oxidative stress was evaluated using the in vitro red blood cell model,while the effect of PEKS on diclofenacinduced oxidative stress was examined in vivo in rats.Platelet-rich plasma and platelet-poor plasma were used for anticoagulant and antiplatelet activities of PEKS.Results:PEKS revealed similar protein bands on SDS-PAGE under reduced and non-reduced conditions.Several acidic proteins were present in native PAGE.PEKS showed antioxidant properties by scavenging DPPH with an IC50 of 24.58μg.PEKS exhibited a protective effect on NaNO2 induced oxidative stress in red blood cells by restoring the activity of stress markers.In addition,PEKS alleviated diclofenac-induced tissue damage of the liver,kidney,and small intestine.PEKS showed an anticoagulant effect in both in vivo and in vitro experiments by enhancing normal clotting time.PEKS did not affect prothrombin time but increase activated partial thromboplastin time.Furthermore,PEKS inhibited adenosine diphosphate and epinephrine-induced platelet aggregation.Conclusions:PEKS protects tissues from oxidative stress and exhibits antithrombotic activity.     

Prevalence of methicillin resistant Staphylococcus aureus in Karnataka

This study was undertaken to find out the prevalence of methicillin resistant Staphylococcus aureus (MRSA) infection in our hospital and to compare their antibiotic susceptibility pattern with methicillin sensitive Staphylococcus aureus (MSSA). 100 strains of Staphylococcus aureus isolated from various clinical samples were screened for MRSA by disc diffusion method using 1 gm oxacillin disc. Antibiotic sensitivity testing was done by Kirby-Bauer's disc diffusion method. Out of these, 43% were identified as MRSA and the remaining 57% were MSSA. There was a marked difference in antibiotic sensitivity pattern of these M RSA versus the MSSA isolates. None of the MRSA isolate was found to be sensitive to amoxycillin while 36.8% of MSSA were sensitive to this antibiotic. 9.3%, 18.6%, 34.9% and 95.3% of MRSA were sensitive to cotrimoxazole, cloxacillin, ciprofloxacin and chloramphenicol, while 75.4%, 92.9%, 91.2% and 94.7% of MSSA were sensitive to these antibiotics respectively. Sensitivity to macrolide group of antibiotics like erythromycin and roxithromycin were seen in 7% and 14% of MRSA in comparison to 85.9% and 91.2% of MSSA respectively. Amongst the aminoglycosides like gentamicin and amikacin, the sensitivity of MRSA was found to be 18.6% and 46.5% and that of MSSA was 98.2% and 94.7% respectively. Sensitivity to cephalosporins like cephalexin and cefotaxime was seen in 23% and 25.5% of MRSA, whereas 100% of MSSA were sensitive to these antibiotics. All Staphylococcus aureus isolates were found to be uniformly sensitive to vancomycin. Majority of the isolates belonged to phage group III and the common phage types were 54, 54/75 and 54/75/85.     

Antidiarrheal effect of fractions from stem bark of Thespesia populnea in rodents: Possible antimotility and antisecretory mechanisms

ObjectiveTo evaluate antidiarrheal activity of the fractions of aqueous extract from stem barks of Thespesia populnea (Malvaceae).MethodsFrom the aqueous extract three fractions namely ethyl acetate fraction (EAF), methanolic fraction (MF) and residue fraction (RF) were made and studied for antidiarrheal activity. Antidiarrheal activity of the fractions were evaluated in castor oil induced diarrhea, prostaglandin E₂ (PG-E₂) induced diarrhea and charcoal meal test as in vivo models and the most potent fraction was further evaluated with in vitro models to determine the possible antimotility effect.ResultsIn castor oil induced diarrhea model, the RF (10, 25, 50 and 100 mg/kg, po.) and MF (100 mg/kg, po.) has significantly reduced the cumulative wet faecal mass, where as the EAF have not shown any significant antidiarrheal activity, RF was found to be more potent than MF. Based on these results and percentage yield, only RF was evaluated in PG-E₂ induced enteropooling and charcoal meal test. RF (10, 25 and 50 mg/kg) had shown significant inhibition of PG-E₂ induced secretions (antisecretory) and decreased the movement of charcoal in charcoal meal test indicating its antimotility activity. Furthermore, RF has showed significant inhibition of acetylcholine, histamine and BaCl₂ induced contractions on rat colon, guinea pig ileum and rabbit jejunum with EC₅₀ values of 241.7, 303.1 and 286.1 μg/mL, respectively indicating the antimotility effect of RF. The phytochemical analysis of RF showed presence of gums and mucilages and the possible mechanism may be the combination inhibition of elevated prostaglandin biosynthesis and reduced propulsive movement of the intestine.ConclusionsRF possesses good antidiarrheal activity comparing with other two fractions and the possible mechanism thought to be associated with combination of antisecretory and antimolity.