Failure of left ventricular hypertrophy to regress after surgery for aortic valve stenosis

BACKGROUND: Regression of left ventricular (LV) hypertrophy usually follows surgery for aortic stenosis (AS); however, a significant number of ventricles remain hypertrophied. The extent of this phenomenon, the reasons for failure to regress, and its significance are unclear. METHODS: We investigated 43 patients before and after aortic valve surgery and divided them into two groups: 30 patients with regression of LV hypertrophy (Group A) and 13 patients without regression (Group B). Preoperative echocardiographic measurements, clinical status, and operative factors were compared between the two groups. The patients were followed up for 42 +/- 22 months for the occurrence of hospitalization for congestive heart failure (CHF) or death. RESULTS: Preoperatively, the two groups were similar except for an excess of patients in New York Heart Association (NYHA) functional Class IV and a greater incidence of old myocardial infarcts in Group B. Postoperatively, Group B patients had larger LVs with decreased systolic function. This was associated with a poor prognosis (23% mortality and 38% CHF vs 0% and 4% for Group A patients, P = 0.0002). Cox regression analysis showed previous myocardial infarction (P < 0.001) and percent mass reduction (P = 0.019) to be independent predictors of CHF or death. CONCLUSIONS: Successful regression of LV mass is difficult to predict before surgery; however, its absence is related strongly to a poor long-term prognosis.     

Lack of apoptosis in the hypoxic brain of a rat model mimicking cyanotic heart disease

OBJECTIVE: To assess the effect of chronic hypoxia on brain neuronal apoptosis, an animal model mimicking cyanotic heart disease was utilized. METHODS: Rats were placed in an hypoxic environment at birth and oxygen levels were maintained at 10% in an air-tight Plexiglass chamber. Controls remained in room air. Animals were sacrificed and the brains were harvested at 1 and 4 weeks, respectively. RESULTS: Significant polycythemia developed in the hypoxic rats at 1 and 4 weeks. Indexed brain mass to body weight was significantly increased in the hypoxic groups by 18% (p < 0.01) and 38% (p < 0.01) as compared to controls at 1 and 4 weeks, respectively. There was no difference in the number of apoptotic neurons between the chronically hypoxic rats and controls, as assayed by TUNEL labelling and Hoechst staining. The role of the sphingolipid ceramide was then examined because of its reported role in stress response, growth suppression and apoptosis. It was found that the brain ceramide accumulation was not significantly different in the hypoxic and control groups at 1 and 4 weeks. CONCLUSION: A protective adaptive response to chronic hypoxia in the neonatal brain may exist.     

Contraception in diabetic women: comparative metabolic study of Norplant, depot medroxyprogesterone acetate, low dose oral contraceptive pill and CuT380A

OBJECTIVE: To evaluate the long-term intake of Norplant, depot medroxyprogesterone acetate (DMPA) and low dose oral contraceptive pill (OCs) on glycemic control, lipoprotein metabolism and coagulation profile in diabetic women. METHODS: Prospective comparative study including 80 uncomplicated controlled diabetic women. Twenty women allocated to each group. Clinical, metabolic and coagulation status were followed up at 3, 6 and 9 months' visits. RESULTS: Fasting blood sugar increased in OCs and DMPA users. Total cholesterol (TC) and LDL-cholesterol (LDL-C) decreased in all groups except DMPA where it increased. Triglyceride (TG) only increased in OCs group. HDL-cholesterol (HDL-C) increased with OCs and decreased with Norplant and DMPA. Compared to IUD users, significantly higher percentage TG and HDL-C and lower LDL-C were observed in OCs users, while DMPA users had significantly higher TC and LDL-C and lower HDL-C. Partial thromboplastin time was prolonged in Norplant users. CONCLUSION: In diabetics, Norplant results in minimal metabolic alterations followed by OCs while DMPA has unfavorable outcome.     

Angiogenic factors for the prediction of pre-eclampsia in women with abnormal midtrimester uterine artery Doppler velocimetry

OBJECTIVE: To determine whether assessing uterine perfusion and angiogenic factors concurrently in the second trimester improves the prediction of pre-eclampsia and intrauterine growth restriction (IUGR). METHOD: Plasma levels of soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF) were measured for 108 women with abnormal uterine perfusion on Doppler velocimetry in the 23rd week. Later, 33 cases of pre-eclampsia and 9 of IUGR developed. RESULTS: Compared with the plasma levels of the women whose pregnancies remained normal, sFlt-1 levels were significantly higher and PlGF levels significantly lower in the women whose pregnancies became complicated by pre-eclampsia and/or IUGR (P<0.001). The alterations were more pronounced in cases of early-onset pre-eclampsia and in cases of IUGR that necessitated delivery before 34 weeks. Using the sFlt-1/PlGF ratio, these complications could be predicted with 98% sensitivity, 95% specificity, and 93% positive predictive value. CONCLUSION: Measuring uterine perfusion and angiogenic factors concurrently in the second trimester improved the prediction of pre-eclampsia and IUGR.     

Autoradiographic study of distribution patterns of metals which occur as corrosion products from dental restorations.

Radioactive chromium, cobalt, gold and mercury, all of which may occur as corrosion products from dental restorations, were injected in single doses via the tail vein of mice and an in vivo analysis of their distribution was performed using whole-body autoradiography. Gold seemed to be inert and went mainly to the liver and bones. The other elements studied were distributed widely in the body and remained for a long period of time in specific target organs and tissues.     

Ligands for the peroxisome proliferator-activated receptor-gamma and the retinoid X receptor exert additive anti-inflammatory effects on experimental autoimmune encephalomyelitis

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a member of the nuclear-receptor superfamily that binds to DNA with retinoid X receptors (RXRs) as PPAR-RXR heterodimers. In experimental autoimmune encephalomyelitis (EAE), the gene expression of PPAR-gamma was demonstrated in spinal cord during the course of EAE. Administration of 15-deoxy-(12,14)-prostaglandin J2 (15d-PGJ2) or 9-cis-retinoic acid (RA) alone at the onset of clinical signs of EAE reduced the severity of disease, however, their combination resulted in enhanced amelioration of disease. These results suggest that use of RXR specific ligands may be highly effective when combined with PPAR-gamma agonists in the treatment of autoimmune demyelinating diseases such as multiple sclerosis (MS).     

Health risk assessment for sulfur dioxide pollution in South Durban, South Africa

Concern about health risks from sulfur dioxide (SO2) pollution prompted a health risk assessment for residents of the heavily polluted industrial region of South Durban, South Africa. The U.S. Environmental Protection Agency health risk assessment model was used to evaluate health effects for individuals in 4 age groups on the basis of data for a 3-yr period, from 1997-1999. Under normal exposure conditions, the level of risk was low (Hazard Quotient < 1); only under the worst-case scenario (exposure 24 hr/day) was there a significant risk of developing health effects. Inasmuch as these results are contrary to the popularly held belief that residents have a high risk of developing SO2-related respiratory diseases under normal exposure conditions, future studies should more thoroughly investigate exposure patterns and verify the authors' assumption that indoor SO2 levels are zero.     

Cerebral mycotic aneurysm in a child with Down's syndrome: a unique association

Mycotic aneurysms are rare complications in patients with infective endocarditis, particularly in the pediatric population. We report a case of mycotic aneurysm of the middle cerebral artery complicating bacterial endocarditis in a child with Down's syndrome. The patient was successfully treated medically without the need for surgical intervention.