Angiotensinogen M235T gene variants and its association with essential hypertension and plasma renin activity in Malaysian subjects: A case control study

BACKGROUND: Essential hypertension is a major public health concern worldwide where its prevalence accounts for various cerebrovascular diseases. A common molecular variant of angiotensinogen (AGT), the precursor of potent vasoactive hormone angiotensin II, has been incriminated as a marker for genetic predisposition to essential hypertension in some ethnics. This case-control study was designed not only to determine the association of the AGT M235T gene variants with essential hypertension, but also its relationship to Plasma Renin Activity (PRA) in subjects attending the Health Clinic, Kuala Lumpur, Malaysia. METHODS: The study involved 188 subjects, 101 hypertensives and 87 normotensives. Consents were obtained from all the participated subjects. M235T gene variants were investigated using allele specific polymerase chain reaction and PRA was determined by radioimmunoassay. Hypertensinogenic factors such as dietary habits, physical activity, smoking and drinking habits were assessed using a pre-tested questionnaire. RESULTS: The genotype and allele distribution of the M235T variant differed significantly in hypertensives and normotensives (χ(2 = )23.184, P < 0.001 and χ(2 )= 21.482, P < 0.001, respectively). The odds ratio for hypertension was 1.36 (95% confidence interval 1.03–1.80) for subjects with homozygous mutated allele TT of the M235T variant compared with other genotypes or 1.98 (95% confidence interval 1.46–2.67) for those carrying T allele compared to those carrying M allele. Plasma Renin Activity is also significantly higher in hypertensive subjects (PRA = 3.8 ± 2.5 ngAI/ml/hr for hypertensives, PRA = 2.6 ± 1.3 ngAI/ml/hr for normotensives, P < 0.001), but was not significantly different between groups of genotypes (P = 0.118). CONCLUSION: The M235T variant of the AGT is significantly associated with essential hypertension whereas the genotype TT or allele T is a possible genetic marker or risk factor for hypertension in Malaysian subjects

Lightpath design & management system for IP-over-CWDM networks with ROADMs, employing parallel processing

A lightpath design and management system with parallel processing capabilities and a flexible upgradability has been designed and implemented for IP-over-CWDM networks with ROADMs. The system can process applications composed of some sub applications in parallel in multi machines for high-speed performance. In addition, the system was designed to have a flexible upgradability, i.e. no changes of the system programs are required when adding new functions. The system functions are to design lightpaths and wavelengths allocated to ROADMs for the lightpaths required to groom given traffic. The system can also search possible lightpath routes made by ROADMs with specified switch states, and output the total optical losses of the routes. By the new system implemented for the parallel processing, the total time to obtain the results for a 5-node IP-over-CWDM network was reduced down to 65% of the total time by the system with a single machine without parallel processing