Association of aldosterone synthase (CYP11B2 C-344T) gene polymorphism & susceptibility to essential hypertension in a south Indian Tamil population

BACKGROUND & OBJECTIVE

Renin-angiotensin aldosterone system (RAAS) plays an important role in the regulation of blood pressure. Aldosterone, synthesized by aldosterone synthase in the adrenal cortex is encoded by the CYP11B2 gene. In this case-control study we examined the association between CYP11B2 C-344T polymorphism and essential hypertension in south Indian Tamil population.

METHODS

The study was conducted in 406 hypertensive cases and 424 healthy controls from Tamil population. Genotyping was performed by PCR-restriction fragment length polymorphism method. Statistical analysis was performed by logistic regression analysis.

RESULTS

The 344TT homozygous variant genotype (OR-1.8; 95% CI: 1.1-2.8; P=0.02) and T allele (P=0.007) were found to be significantly associated with hypertension. In gender based analysis, the risk was significantly higher in male hypertensives (OR-1.8; 95% CI: 1.0-3.6, P=0.05) but not in female subjects.

INTERPRETATION & CONCLUSION

A significant association between CYP11B2 gene polymorphism and essential hypertension was observed and the risk was confined to male subjects in south Indian Tamil population.

Reduction of Selenate and Selenite to Elemental Selenium by a Pseudomonas stutzeri Isolate

A Pseudomonas stutzeri isolate rapidly reduced both selenite and selenate ions to elemental selenium at initial concentrations of both anions of up to 48.1 mM. Optimal selenium reduction occurred under aerobic conditions between pH 7.0 and 9.0 and at temperatures of 25 to 35 degrees C. Reduction of both selenite and selenate was unaffected by a number of anions except for sulfite, chromate, and tungstate ions, which inhibited both growth and reduction.

An improved pollen collection and cryopreservation method for highly recalcitrant tropical fruit species of mango (Mangifera indica L.) and litchi (Litchi chinensis Sonn.)

An improved method for pollen collection from freshly dehiscing anthers of mango (Mangifera indica L.) and litchi (Litchi chinensis Sonn.) using the organic solvent cyclohexane has been devised. Using this method pollen quantity sufficient for large scale pollinations could be collected and stored for future use. Transport of pollen in viable conditions over long distances, from site of collection (field genebank) to cryolab was successfully devised for both these fruit species. Cryopreservation was successfully applied to achieve long-term pollen storage over periods of up to four years. Pollen viability was tested using in vitro germination, the fluorochromatic reaction (FCR) method and by fruit set following field pollination. On retesting, four year cryostored pollen of different mango and litchi varieties showed high percentage viability as good as fresh control pollens. Pollens of more than 180 cultivars of mango and 19 cultivars of litchi have been stored in the cryogenebank using the technology developed, thus facilitating breeding programmes over the long-term.

Physico-Phytochemical investigation and Anti-inflammatory screening of Capsicum annum L. and Hemidesmus indicus (Linn.) R. Br

Capsicum annum L. (Family: Solanaceae) and Hemidesmus indicus (Linn.) R.Br. (Family: Asclepiadaceae) are commonly used in Tamilnadufor treating various ailments in the native system of medicine. The hydroalcoholic extracts of both plants at dose level of 100 mg/kg body weight showed demonstrable anti-inflammatory activity in the carrageenan-induced hind paw model in rats. Nevertheless, the overall anti-inflammatory activity exhibited by the extracts are found to be less as compared with that of standard drug Indometacin. Preliminary physico-phytochemical analysis of the plants in question were attempted. The results are highlighted and discussed.

Aneurysm of mitral aortic intervalvular fibrosa--a case report and review

Aneurysm of mitral aortic intervalvular fibrosa is a rare but dreaded complication of aortic valve endocarditis. We report a patient with large aneurysm of mitral aortic intervalvular fibrosa that ruptured into left atrium, secondary to aortic valve endocarditis. Patient underwent a successful surgical repair.

Venous thromboembolism (VTE) and erythropoiesis-stimulating agents (ESAs) in breast cancer: a single tertiary care center experience from the University of Arkansas for Medical Sciences (UAMS)

Abstract #6137

Introduction: ESAs have been associated with increased rates of death, myocardial infarction, stroke and venous thromboembolism(VTE) in dialysis patients especially when targeted to higher hemoglobin levels. VTE and progression of cancer have also been reported in cancer patients receiving ESAs with chemo- and/ or radiotherapy, without a strict correlation with hemoglobin levels. ESAs are the subject of intense scrutiny by the FDA and the center for Medicare and Medicaid Services. We conducted a retrospective cohort study of a relatively homogeneous group of breast cancer patients. The objectives were to detect any increased risk of VTE with ESA exposure, and to correlate it with the hemoglobin/hematocrit levels.
 Methods: Data were extracted from Logician, an electronic medical record database used in the Medical Oncology Clinic at UAMS. The study cohort included breast cancer patients treated at UAMS with chemotherapy between July 1, 2004 and July 1, 2007. Patients with prior history of VTE were excluded. The patients were followed until September 9, 2007 for ESA(Erythropoietin/Darbepoietin) exposure and development of VTE. The association between ESA exposure and VTE development was assessed using Cox regression with ESA exposure as a time-dependent covariate, and the results were reported as the hazard ratio (HR) along with associated chi-square statistic and p value.
 Results: 483 patients (482 female, 1 male) met the study inclusion criteria. Median (range) age was 56 yrs (27-89). 107 (22%) were African American, 361 (75%) were Caucasian, and 15 (3%) in other categories. 9 out of the total 483 pts (1.86%) developed a VTE [7 Deep Vein Thromboses (DVTs) and 2 pulmonary embolism (PE)]. 63 subjects (13%) were exposed to ESAs during the study period, and 1 of them developed a DVT. The mean Hgb/Hct in the 62 patients exposed to ESAs who did not develop VTE was 11.34/35.26; the 1 patient exposed to ESA with DVT had a Hgb/Hct of 12.5/37.9. Among the 420 patients not exposed to ESAs, 6 developed a DVT; their mean Hgb/Hct was 12.95/39.4. The 414 pts without a DVT had mean Hgb/Hct of 12.66/38.55. Comparisons of the Hgb/Hct values in the various groups with or without VTE and, with or without ESA exposure showed no significant differences between any of the groups. Cox regression showed little evidence of increased risk with ESA use for either VTEs in general (HR=1.83; X21=0.57, P=0.45) or DVT in particular (HR=1.08; X21=0.005, P=0.94).
 Conclusions: The number of VTEs in the study patients was very small, and much lower than previous reports. There was no evidence of increased risk of VTE from ESA exposure. However, due to the small number of events, this study lacked the power to detect an ESA effect unless the effect was huge. On the other hand, the very small number of VTEs in the ESA- exposed patients to may reflect our conservative ESA usage in breast cancer patients, and is reassuring that when used appropriately, ESA use is safe.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6137.

A Flavonoid Glycoside from the Leaves of Morinda Tinctoria

Tilianin (acacetine-7- O-β-D-glucopyranoside) was isolated from the ethyl acetate extract of Morinda tinctoria Roxb. and its structure established unambiguously by a series of 1D- and 2D-NMR analyses. This is the first record of this compound for this species. The antioxidant activity of tilianin, determined using the DPPH scavenging assay, was measured with an IC50 value of 57.5 μg/mL.

Unsupervised and uncued segmentation of the fundamental heart sounds in phonocardiograms using a time-scale representation

A methodology is proposed to segment and label the fundamental activities, namely the first and second heart sounds, S1 and S2of the phonocardiogram (PCG). Information supplementary to the PCG, such as a cue from a synchronously acquired electrocardiogram (ECG), subject-specific prior information, or training examples regarding the activities, is not required by the proposed methodology. A bank of Morlet wavelet correlators is used to obtain a time-scale representation of the PCG. An energy profile of the time-scale representation and a singular value decomposition (SVD) technique are used to identify segments of the PCG that contain the fundamental activities. The robustness of the methodology is demonstrated by the correct segmentation of over 90% of 1068 fundamental activities in a challenging set of PCGs which were recorded from patients with normally functioning and abnormally functioning bioprosthetic valves. The PCGs included highly varying fundamental activities that overlapped in time and frequency with other aberrant non-fundamental activities such as murmurs and noise-like artifacts.

Microwave-assisted rapid extraction of red dye from Caesalpinia sappan heartwood

Since ancient times Caesalpinia sappan heartwood dye has been well-known for its medicinal and dyeing properties. Isolation of the red dye using both conventional and newly developed microwave method was carried out. The conventional heating of 2 h provided 0.656 +/- 0.049 g of the dye and by microwave heating at 540 W for 20 min, the yield obtained was 0.747 +/- 0.047 g. Both the dyes were found to be the same as evidenced by UV, TLC and HPTLC studies. Antioxidant activity of the dyes was also carried out using DPPH and nitric oxide methods to confirm the similarity in their biological activity. The procedure developed can be used for the fast extraction of the red dye of C. sappan without affecting the nature of the product.

Rational treatment of pulmonary infections in patients with cystic fibrosis

The life expectancy of patients with cystic fibrosis has increased markedly during the past two decades due in large part to improved clinical care, including the use of more effective antimicrobial agents for Pseudomonas. However, the chronic lung disease of CF remains the principal cause of mortality. A growing understanding of the complex interactions between infection and inflammation has led to new approaches for treatment, including chronic use of aerosolized antibiotics, particularly tobramycin, in patients known to be colonized/infected with P. aeruginosa and anti-inflammatory treatments to slow the progression of lung disease.

CYP2D6 genotype and phenotype relationship in South Indians

BACKGROUND

Genotypes of the drug-metabolizing enzyme CYP2D6 influence plasma levels of 25% of commonly prescribed drugs. This is the first study in India to investigate the genotype-phenotype relationship of CYP2D6.

AIM

To study the influence of some CYP2D6 genotypes on the metabolism of its substrate dextromethorphan in healthy South Indian volunteers and to assess the contribution of the CYP2D6*10 and CYP2D6*4 alleles.

MATERIALS AND METHODS

Twenty-six subjects from a previous CYP2D6 genotyping study of healthy volunteers were included for phenotyping in this study. Selected volunteers belonged to any one of three genotype groups:Group I - two normal activity alleles, Group II - one reduced activity allele and one normal activity allele and Group III - one loss of function allele along with either a wild type or reduced activity allele. Volunteers were phenotyped for the CYP2D6 enzyme using dextromethorphan as probe drug. Concentrations of the parent drug and metabolite dextrorphan were estimated using high performance liquid chromatography. Metabolic ratios were calculated as the ratio of parent drug to metabolite in 0-8h urine samples.

STATISTICAL ANALYSIS

Metabolic ratios from each genotype group were compared using the Mann-Whitney test at 5% significance, to observe their difference between genotype groups.

RESULTS

The mean metabolic ratios+/-SD in Groups I, II and III were 0.0039+/-0.0031, 0.0032+/-0.0017 and 0.0391+/-0.0331 respectively. The mean metabolic ratio of Group III was significantly higher when compared with Groups I or II. In heterozygous individuals, the *1 or *2 alleles compensated for the reduced enzyme activity due to the *10 allele. However, if a heterozygous individual had a *4 allele, the reduced enzyme activity could not be compensated by the *1 or *2 alleles.

CONCLUSIONS

The CYP2D6 enzyme activity was found to be decreased in individuals carrying *4 or *5 alleles. The *1 or *2 allele could compensate for the reduced function due to *10 allele, but not for the loss of function due to *4 allele.

Right atrial myxoma arising from the inferior vena cava

A middle-aged man presented with recent-onset dyspnea and recurrent syncopal attacks at our institute. Echocardiography revealed a large mass arising from the inferior vena cava and prolapsing into the right atrium and ventricle. Histopathologic examination revealed the classic features of a myxoma. This report is of a rare case of a cardiac myxoma arising from the inferior vena cava.

Surgical outcomes and strategy of hypertrophic obstructive cardiomyopathy

OBJECTIVE

To evaluate the surgical clinical results of hypertrophic obstructive cardiomyopathy.

METHODS

We retrospectively collected data on 24 patients who underwent surgical management in the past ten years in two hospitals in China and Madras Medical Mission in India. Myomectomy was carried out on all patients. Among them 3 patients underwent mitral valve replacement; 2 patients underwent mitral valve repair (anterior mitral leaflet plication); 2 patients underwent aortic valve replacement; 1 patient underwent aortic valve repair; 2 patients underwent aortic root replacement; 1 patient underwent Bentall's procedure and 1 patient underwent coronary artery bypass grafting because of a breached muscle bridge.

RESULTS

One patient died of post-operative heart failure. The mean follow-up time was 4.3 years. There was significant improvement in the symptomatic status. Sixteen patients were asymptomatic with good effort tolerance and only four patients had New York heart association (NYHA) Classes I-II due to associated valvular lesions.

CONCLUSION

Our experience proved that symptomatic hypertrophic obstructive cardiomyopathy or non-symptomatic hypertrophic obstructive cardiomyopathy with combined heart disease is indication for surgery as surgical intervention could get better clinical results in this kind of patients compared with other non-surgical method because it beneficially reduces the systolic anterior motion (SAM) of the mitral valve leaflet, which could not be avoided by other non-surgical treatment.

Influence of the CYP2C9 AND CYP2C19 polymorphisms on phenytoin hydroxylation in healthy individuals from south India

BACKGROUND AND OBJECTIVES

Phenytoin, a widely used anti-epileptic drug, is metabolized mainly by CYP2C9 (90%) and partly by CYP2C19 (10%) to its major metabolite 5-(para-hydroxyphenyl)-5- phenylhydantoin (p-HPPH). The CYP2C9 and CYP2C19 genes encoding these enzymes are polymorphically expressed and most of the variants result in decreased metabolism of the respective substrates. The present study was undertaken to investigate the influence of the CYP2C9*2 and *3 as well as CYP2C19*2 and *3 variant genotypes on phenytoin hydroxylation in healthy subjects from south India.

METHODS

A total of 27 healthy, unrelated, subjects were administered a single oral dose of 300 mg phenytoin. Four hours later, 5 ml of blood was collected and genotyped for CYP2C9*1, *2, *3, CYP2C19*1, *2 and *3 by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Phenytoin and the major metabolite p-HPPH were estimated by reverse phase HPLC. The metabolic ratio was calculated as concentration of phenytoin/p-HPPH.

RESULTS

A significant correlation was observed between the CYP2C9 genotype and metabolic ratio of phenytoin/p-HPPH (r = 0.472, 95% CI 0.100 to 0.728; P = 0.01). While no association was found with CYP2C19 alone, a significant correlation was observed between the combined CYP2C9 and CYP2C19 genotypes and phenytoin metabolic ratio (r = 0.507, 95% CI 0.146 to 0.749; P< 0.01).

INTERPRETATION AND CONCLUSION

CYP2C9*2 and *3 mutant alleles caused decreased hydroxylation of phenytoin in vivo, whereas the mutant alleles of CYP2C19 played only a minor role in the metabolism of phenytoin in subjects of our study. The results of present preliminary study needs to be confirmed with a larger sample.