The precancer risk of betel quid chewing, tobacco use and alcohol consumption in oral leukoplakia and oral submucous fibrosis in southern Taiwan

In areas where the practise of betel quid chewing is widespread and the chewers also often smoke and drink alcohol, the relation between oral precancerous lesion and condition to the three habits is probably complex. To explore such association and their attributable effect on oral leukoplakia (OL) and oral submucous fibrosis (OSF), a gender–age-matched case–control study was conducted at Kaohsiung, southern Taiwan. This study included 219 patients with newly diagnosed and histologically confirmed OL or OSF, and 876 randomly selected community controls. All information was collected by a structured questionnaire through in-person interviews. A preponderance of younger patients had OSF, while a predominance of older patients had OL. Betel quid chewing was strongly associated with both these oral diseases, the attributable fraction of OL being 73.2% and of OSF 85.4%. While the heterogeneity in risk for areca nut chewing across the two diseases was not apparent, betel quid chewing patients with OSF experienced a higher risk at each exposure level of chewing duration, quantity and cumulative measure than those who had OL. Alcohol intake did not appear to be a risk factor. However, cigarette smoking had a significant contribution to the risk of OL, and modified the effect of chewing based on an additive interaction model. For the two oral premalignant diseases combined, 86.5% was attributable to chewing and smoking. Our results suggested that, although betel quid chewing was a major cause for both OL and OSF, its effect might be difference between the two diseases. Cigarette smoking has a modifying effect in the development of oral leukoplakia

Angiotensin-converting enzyme gene insertion/deletion polymorphism is associated with risk of oral precancerous lesion in betel quid chewers

To investigate whether angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism is related to the risk of oral precancerous lesions (OPL) in Taiwanese subjects who chew betel quid, a total of 61 betel quid chewers having OPL were compared with 61 asymptomatic betel quid chewers matched for betel quid chewing duration and dosage. The frequency of homozygote for ACE D variant is significantly higher in the case subjects than that of the controls (44.3 vs 24.6%; P=0.0108). The adjusted odds ratio of the D homozygous for the risk of OPL is 8.10 (95% confidence interval (CI)=2.04–32.19, P=0.003). In the allelic base analysis, the D allele is also significantly associated with higher risk of OPL. When grouping the study subjects by smoking status, the association between ACE I/D polymorphism and risk of OPL was only observed in nonsmokers. Our results support the theory that genetic factors may contribute to the susceptibility of OPL and suggest that smoking and genetic factors may be differently involved in the development of OPL

The role of renin in hypertension : an old dog with new bite / Johannes Marthinus van Rooyen

Foreword: Tigerstedt and Bergman discovered in 1898 the pressure-raising substance from saline rabbit kidney extracts and called the extract renin, however other scientists could not confirm their findings and in 1934, Harry Gold blatt published his results obtained in dog experiments where he clamped one or both renal arteries with a silver clamp. Numerous attempts showed no increases in plasma renin levels in patients with essential hypertension or that renin had any significant physiologic action of its own in humans. Braun-Menendez discovered that renin acted enzymatically on angiotensinogen (plasma protein) to form angiotensin I (inactive) and is further hydrolysed by converting enzyme to form angiotensin II (vasoconstrictor), which increases the blood pressure when it is low. This is the old dog and because renin is not even mentioned in the JNC-VII (US) and the ESH (European) guidelines and when one do a renin profiling on patients/participants and apply the laragh method to individualize the type of hypertension (volume or renin), it is evident that renin plays a large role in the maintenance of normal blood pressure and hypertension. In South African blacks whose hypertension is not under control. this will have a large impact on individualizing specific pathology and treatment and this will give the old dog new bite