Comparison of antioxidant activity in commercial Ginkgo biloba preparations

AIM: To compare the relative levels of antioxidant activity in vitro in Ginkgo biloba samples (in tablet or capsule form) from different commercial suppliers, to determine whether some brands may be more efficacious in their potential to increase endogenous antioxidant activity, and thereby counter oxidative stress related disorders. DESIGN: Antioxidant activity of the above sample extracts was determined in vitro against the ABTS.(+) (2-2'-amino-bis-3-ethylbenzthiazoline-6-sulfonic acid) radical, relative to Trolox (water-soluble vitamin E analogue) antioxidant standards, using an established assay procedure. OUTCOME MEASURES: The relative antioxidant activity of G. biloba sample extracts was expressed in terms of millimoles per liter of Trolox equivalent (TE) for the initial extract, micromol TE per whole tablet, nmol TE per mg tablet, and nmol TE per mg ginkgo content. RESULTS: Data (as mean +/- standard deviation (SD) from 4 separate estimations) obtained in this study showed a considerable variation (approximately 50-fold) in the level of antioxidant activity in preparations from different suppliers, particularly when compared on an equivalent (i.e., nmol TE/mg ginkgo) basis. Of the 18 products investigated, the highest level of antioxidant activity (whether expressed as micromol TE per whole tablet or nmol TE/mg ginkgo) was obtained for Pharma Nord Bio-Biloba (Pharma Nord, Morpeth, UK) tablets (p < 0.05, Dunnett's statistical test). CONCLUSIONS: Some of the apparent variation in antioxidant activity of the various products investigated can be accounted for in terms of the physical nature of the G. biloba (i.e., dried leaf powder or standardized concentrated extract) used in tablet formulation. However, even when comparing products based on concentrated extract, the data demonstrated that there is still a considerable variation in antioxidant activity. Presumably this may result from differences in the manufacturing process between suppliers, which in turn may limit the efficacy of these preparations in the prevention or treatment of disease.     

The effects of atorvastatin treatment on the fibrinolytic system in dyslipidemic patients

Statins have pleiotrophic effects related to the pathogenesis of atherosclerosis and thrombogenicity of the vessel wall beyond lipid lowering. The aim of the present study was to examine the effect of atorvastatin treatment on the fibrinolytic system in patients with dyslipidemia. The investigation was carried out on 41 dyslipidemic patients (21 males and 20 females) with a mean age of 53.8 years (range, 30-76). The patients were divided into subgroups according to their cholesterol and triglyceride levels as hypercholesterolemic (n = 26) and mixed-type hyperlipidemic (n = 15) and their risk factors for coronary heart disease including age, sex, hypertension, obesity, smoking, and family history. The patients were started on atorvastatin 10 mg/day, and evaluated within 6-12 weeks to assess the changes in fibrinolytic parameters including global fibrinolytic capacity, plasminogen activator inhibitor type-1 and tissue plasminogen activator, and lipids. After successful lipid-lowering therapy, global fibrinolytic capacity (P = 0.003) and tissue plasminogen activator levels (P = 0.04) were found to be increased and plasminogen activator inhibitor type-1 levels (P = 0.02) decreased in dyslipidemic patients. Global fibrinolytic capacity levels increased (P < 0.001) and plasminogen activator inhibitor type-1 levels decreased (P = 0.01) in patients with hypercholesterolemia (n = 26). However, no significant changes were observed in fibrinolytic parameters in patients with mixed-type hyperlipidemia (n = 15). When the patients were separately evaluated according to risk factors, significant beneficial effects on the fibrinolytic system were observed, especially in patients without obesity and hypertension as well as in older patients and males. These findings suggest that atorvastatin treatment has a beneficial effect on the fibrinolytic system in patients with hypercholesterolemia, but not in patients with mixed-type hyperlipidemia. Further studies are needed to show whether higher doses and longer periods of lipid lowering treatment have beneficial effects in patients with mixed type hyperlipidemia and some risk factors.     

Associations between elevated resting heart rate and subclinical atherosclerosis in asymptomatic Korean adults undergoing coronary artery calcium scoring

Elevated resting heart rate (RHR) and the presence of coronary artery calcium (CAC) are closely related with inflammatory activity and cardiovascular disease outcomes. To date, however, the relationship between a high RHR and CAC has not been well studied, especially in non-western populations. We therefore aimed to examine the cross-sectional relationship between high RHR and the burden of subclinical atherosclerosis as measured by CAC score in a large sample of Korean adults. A total 26,018 subjects were enrolled and underwent CAC screening as part of a broader general health examination. RHR was categorized into four groups as: <60, 60–69, 70–79, and ≥80 beats per minute. Multivariable logistic regression models were employed to estimate the odds of having a CAC score of either >0, >100, or >400 based on RHR. Mean age of the study population was 53.9?±?8.2 years, and 79.7?% were male. After adjustment, each 10 beat per minute increment in RHR was associated with greater odds of having a CAC score above 100 (OR 1.13, 95?% CI 1.08–1.18) or 400 (OR 1.22, 95?% CI 1.13–1.31). Likewise, following adjustment, the odds of having a CAC >100 or >400 for those with a RHR ≥80 beats per minute were 1.42 (95?% CI 1.19–1.69) and 1.86 (95?% CI 1.42–2.47), respectively, compared with those who had a RHR <60 beats per minute. In a large cohort of Korean adults, elevations in the RHR, particularly above 80 beats per minute, were found to be independently associated with the presence of subclinical atherosclerosis as measured by CAC scoring.     

<Emphasis Type="Italic">HLA-B27</Emphasis> Homozygosity and Clinical Features of Ankylosing Spondylitis

Osteoporosis (OP) is a frequent complication of ankylosing spondylitis (AS), even in early stages of the disease, and is associated with elevated levels of biochemical markers of bone turnover, proinflammatory cytokines, and acute-phase reactants. This suggests that systemic inflammatory mediators, such as interleukin-6 and tumor necrosis factor-α, may be involved. Various factors that conceivably work in conjunction with one another also cause bone loss in AS (eg, genetic polymorphisms of vitamin D, low levels of osteoprotegerin and sex steroid hormones, and impaired calcium and vitamin D absorption). Dual x-ray absorptiometry for assessing bone mineral density (BMD) has limitations in patients with AS because of unreliability of spinal measurements, particularly in advanced disease with new bone formation. Femoral neck BMD is reduced and correlates with increased risk of vertebral fractures. Hence, measurement of BMD at the femoral neck may provide the most accurate means of detecting osteopenia and OP and could assess fracture risk in AS patients. No guidelines are available for detection and treatment of OP in AS, and most patients are young men, who are less likely to be screened. The only evidence-based recommendation is that optimal control of disease activity in AS prevents bone loss. A recent study showed a beneficial effect of infliximab therapy on bone turnover markers and BMD in AS. Also, bisphosphonates may be useful in managing OP in AS.     

Acute type A aortic dissection in a patient with ventricular septal defect

We report the case of a 38-year-old man with a long-standing history of a small ventricular septal defect presented with chest pain. Electrocardiography revealed sinus rhythm, ST-segment elevation in leads V1–6. The chest X-ray showed mild cardiomegaly. He underwent cardiac catheterisation laboratory to primary coronary angioplasty. Coronary angiography showed normal coronary arteries. Aortic root angiography revealed type A aortic dissection. Transthoracic and transesophageal echocardiography showed aortic dissection in ascending aorta and a perimembranous ventricular septal defect. Thoracoabdominal CT angiography confirmed the aortic dissection before the surgery.The patient underwent cardiac surgery immediately. The ventricular septal defect and aortic dissection were repaired successfully. The postoperative recovery was uneventful and he has thus far remained asymptomatic at 6 months' follow-up.     

In vitro sensitivity of Blastocystis hominis to garlic, ginger, white cumin, and black pepper used in diet

To determine the growth pattern and in vitro susceptibility of Blastocystis hominis to metronidazole (MTZ), garlic, ginger, white cumin, and black pepper. Stool specimens were collected from 16 irritable bowel syndrome (IBS) and 10 controls between July–November 2010. Stool microscopy and culture for B. hominis was performed. Drug susceptibility assays was done using 0.01 and 0.1 mg/ml of MTZ, garlic, ginger, white cumin, and black pepper. Effect was assessed on B. hominis culture after 48 h. Stool DNA was extracted using stool DNA extraction kit (Qiagen) and polymerase chain reaction (PCR) done using subtype-specific sequence-tagged-site primers. B. hominis genotype 3 and coinfection of 1 and 3 tended to grow well in culture compared to isolated type 1 infection. Exposed to MTZ at a concentration of 0.01 mg/ml, 38% (6/16) B. hominis from IBS did not grow in culture compared to 100% (10/10) of B. hominis from control (p = 0.001). When they were exposed to MTZ at 0.1 mg/ml, 56% (9/16) B. hominis from IBS did not grow in cultures compared to 100% (10/10) from control (p = 0.01). Forty-four percent (7/16) B. hominis from IBS did not grow in culture compared to 100% (10/10) B. hominis from control when exposed to garlic at a concentration of 0.01 mg/ml (p = 0.003) and following exposure to garlic at 0.1 mg/ml, 38% (6/16) B. hominis from IBS did not grow in cultures compared to 100% (10/10) from control (p = 0.001). B. hominis isolates from IBS had a cell count of 6,625 at a MTZ concentration of 0.01 mg/ml that reduced to 1,250 as MTZ concentration was increased to 0.1 mg/ml (p = 0.08). B. hominis from IBS with a mean cell count of 3 × 10⁵ at baseline decreased to 1 × 10⁴ when exposed to garlic at 0.01 mg/ml (p < 0.001) and to 1 × 10³ (p < 0.001) when garlic was 0.1 mg/ml. B. hominis from IBS cell count decreased to 1 × 10⁵ when exposed to white cumin at 0.01 mg/ml (p = 0.01) and to 1 × 10⁵ (p < 0.001) when white cumin was 0.1 mg/ml. Exposed to black pepper at 0.1 mg/ml, cell count of B. hominis from IBS decreased to 1 × 10⁵ (p = 0.01). B. hominis from IBS decreased to 1.3 × 10⁵ exposed to ginger at 0.01 mg/ml (p = 0.001). B. hominis isolates were mostly genotypes 3, type 1 and 3 coinfection, and non-typeable B. hominis isolates. B. hominis isolates from IBS mostly genotype 1 demonstrated an increased sensitivity to garlic at 0.01 mg/ml with a B. hominis cell count of 3,714 compared to 6,142 when exposed to 0.01 mg/ml of MTZ. However, this sensitivity did not increase as garlic concentration was increased to 0.1 mg/ml, for B. hominis cell count was 6,000 compared to 1,428 as MTZ was increased to 0.1 mg/ml.     

Carriage rate of Haemophilus influenzae among preschool children in Turkey

This study was designed to determine the prevalence of healthy Haemophilus influenzae carriers in a random sample of the preschool population in Kayseri, Turkey. The lack of H. influenzae type b (Hib) disease surveillance and epidemiological data on the throat carriage of Turkish children has caused a delay in the introduction of conjugated Hib vaccination into proposed national vaccination programs. Oropharyngeal cultures were collected and cultured on chocolate agar supplemented with 260 microg/ml bacitracin from 683 children between May and June, 2006. One hundred seven (15,6%) of the 683 children studied were found to be as H. influenzae carriers, and 29 (4,2%) isolates were serotype b. Beta-lactamase production was detected in four isolates (3.7%). According to multivariate analysis, the sex of the child and the number of people sharing the same room with the child significantly influenced the odds of carrying H. influenzae. Age, having older siblings, passive smoking, respiratory infection during the last 30 days, number of people in the household, attending kindergarten or a day-care center, and household income were not significant variables. Our results suggest that there is a strong relationship between exposure to large numbers of children and H. influenzae carriage.     

Impairment of flow-mediated vasodilatation of brachial artery in patients with Cushing's Syndrome

Background Cushing’s Syndrome (CS) is associated with excess and premature cardiovascular disease. Endothelial dysfunction is the initiating event in the development of atherosclerosis. Endothelial function is assessed by flow-mediated dilatation (FMD) of brachial artery. The aim of this study was to assess FMD in patients with CS. Methods We prospectively evaluated 22 patients with CS (12 women, 10 men; aged 42 ± 11 years, serum cortisol 28.2 ± 14 μg/dl, 24-h urinary free cortisol (UFC) 269 ± 92 μg/day), and 23 control subjects (13 women, 10 men; aged 43 ± 10 years, serum cortisol 14 ± 4 μg/dl, 24 h cortisol 60 ± 22 μg/day). Endothelial function, measured as FMD of the brachial artery using ultrasound, was calculated in two groups. Endothelial function was evaluated by assessing 1-min postischemic FMD of the brachial artery. Results FMD was lower in patients with CS than that in those without (11.7 ± 4.8% vs. 15.8 ± 3.2%, P = 0.0001, respectively). There was no significant difference between two groups regarding baseline diameter of brachial artery. But, hyperemia diameter was lower in patients with CS than without CS (3.6 ± 0.22 mm vs. 3.9 ± 0.19 mm, P = 0.04, respectively) Conclusion Endothelium-dependent FMD may impair in patients with CS compared to controls. Measurement of endothelial function may identify high-risk individuals early and therapy to reduce or retard endothelial dysfunction in patients with CS may lead to decreased cardiovascular morbidity and mortality.     

Infective endocarditis in patients with congenitally malformed hearts: characterization of the syndrome in a developing country

OBJECTIVE: Cardiac surgery for correction or palliation of congenital cardiac disease in infancy and childhood remains a privilege that is rarely accessible to two-thirds of the world's population. This imbalance has created a unique spectrum of illness in patients with underlying congenital cardiac disease and complicating infective endocarditis in developing countries, including Pakistan. In this study, we characterize endocarditis as seen in such patients presenting in Karachi. PATIENTS AND SETTINGS: We reviewed retrospectively patients admitted to Aga Khan University with underlying congenitally malformed hearts and endocarditis between 1991 and 2004. RESULTS: We identified 48 patients with endocarditis according to the modified Duke Criterions, with just over half the cases (54%) classified as definite endocarditis. Of the patients, 23 (49%) patients were more than 16 years old. Uncorrected left-to-right-shunts, tetralogy of Fallot, and congenital mitral valvar disease were the most common underlying defects. Patients with cyanotic defects, particularly of the complex type, were underrepresented (4%). Only 11 (22.9%) of the patients had a previous palliative or corrective surgery. In one-third of the patients (16), streptococcal species were identified as the microbiologic cause of endocarditis, and 22 (45.8%) had culture-negative endocarditis. In contrast, Staphylococcus aureus and enterococci caused endocarditis in only one patient each. There were no differences in mortality or complications between cyanotic and acyanotic congenital defects. Surgery was performed in nine (18.7%) patients with endocarditis, and of these, 13 (27.1%) died. CONCLUSIONS: In contrast to the developed world, endocarditis in the developing countries, such as Pakistan, complicates uncorrected left-to-right shunts and tetralogy of Fallot, probably because patients with complex cyanotic defects fail to survive long after birth due to the lack of available surgery. Almost half of patients had culture-negative endocarditis, likely related to several factors.