Gene polymorphisms in the TNF locus and the risk of myocardial infarction.

We investigated two genetic polymorphisms in the tumor necrosis factor locus (TNF-alpha -308 G-->A and LT-alpha +252 A-->G) as risk factors for coronary atherothrombotic disease (CAD) by determining its prevalence in 148 survivors of myocardial infarction (MI) with angiographically-proven severe CAD, and in 148 age-, gender- and race-matched controls. The odds ratio (OR) for MI related to the mutant TNF-alpha and LT-alpha alleles was 0.8 (CI95: 0.4-1.3) and 1. 3 (CI95: 0.8-2.0), respectively. We also sought interaction of smoking and metabolic risk factors for MI with each mutant genotype. Smokers not carrying the LT-alpha +252 A-->G mutation had a risk of MI of 2.7 (CI95: 1.4-5.4) whereas in smoking carriers the risk was 6. 9 (CI95: 3.4-14.1). An interactive effect of the LT-alpha mutation may also exist with dyslipidemia (OR for MI in non-carriers was 12 [CI95: 3.2-41.3] and in carriers the OR was 39, [CI95: 5.1-301] and with obesity (OR for MI was 2.7, [CI95: 1-7.2] in non-carriers and in carriers the OR was 6 [CI95: 2.1-16.8]). Lastly, the OR for MI in obese non-carriers of TNF-alpha -308 G-->A was 2.8 (CI95: 1.3-6) and in obese carriers the OR was 14.5 (CI95: 1.8-113). Although significant interactive effects could not be detected, the findings suggest that interaction of polymorphisms in the TNF locus with major risk factors for CAD may exist, and should be explored in larger studies.

The effect of non-antihypertensive doses of angiotensin converting enzyme inhibitor on myocardial necrosis and hypertrophy in young rats with renovascular hypertension.

In renovascular hypertensive rats, low doses of angiotensin converting enzyme (ACE) inhibitors have been found to prevent myocardial hypertrophy independent of blood pressure level. This finding would suggest humoral rather than mechanical control of myocyte growth. The aim of this study was to examine the effect of nonantihypertensive doses of ACE inhibitor on myocardial hypertrophy and necrosis in hypertensive rats. Renovascular hypertension (RHT) was induced in four-week-old Wistar rats. Twenty-eight animals were treated for four weeks with three doses of ramipril (0.01, 0.1 or 1. 0 mg/kg/day, which are unable to lower blood pressure. Fourteen animals were not treated (RHT group). A sham operated, age/sex-matched group was used as control (n = 10). Myocardial histology was analysed in 3 microm thick sections of the ventricle stained with either haematoxylin-eosin, reticulin silver stain or Masson's trichrome. There was a significant correlation between systolic blood pressure and left ventricular to body weight ratio in both sets of animals: untreated plus controls and ramipril-treated rats. ACE inhibition prevented myocyte and perivascular necrosis and fibrosis in a dose-dependent manner. We conclude that myocardial hypertrophy in rats with renovascular hypertension is directly related to arterial pressure, and that this relationship is not affected by nonantihypertensive doses of ACE inhibitor. Myocardial necrosis/fibrosis and coronary artery damage induced by angiotensin II are prevented by ACE inhibitor in a dose-dependent manner, despite the presence of arterial hypertension.

An atypical form of mucolipidosis III.

We report two sibs showing a very mild form of mucolipidosis III with no clinical signs but isolated involvement of the hip and very mild abnormalities of the spine. This indicates that a storage disease, in particular mucolipidosis III, should be considered in any case of isolated bilateral hip dysplasia. The differences from other reported atypical variants of mucolipidosis III are discussed.