Left ventricular aneurysm repair in rats: structural, functional, and molecular consequences

OBJECTIVES: This study examined the effects of aneurysm repair in a rat model of myocardial infarction on functional indices and on the spatiotemporal distribution of cardiac contractile protein and natriuretic peptide messenger RNA. METHODS: In a rat infarct model, expanded left ventricular aneurysms were plicated 4 weeks after infarction. At 30 weeks, transverse heart sections were taken at 4 levels (apex [level 1] through base [level 4]) and assessed by in situ hybridization histochemistry to determine regional messenger RNA levels of pre-pro-atrial natriuretic peptide, cardiac alpha-actin, skeletal alpha-actin, myosin light chain-2v, and beta-myosin heavy chain. RESULTS: Rats with plicated left ventricular aneurysms had reduced left ventricular endocardial circumference (19%, P <.005), lower heart weight ratio (31%, P <.05), left ventricular end-diastolic pressures (51%, P <.05), and increased +/-dP/dt (34%-38%, P <.05). Cardiac messenger RNA levels of pre-pro-atrial natriuretic peptide were reduced in the septum (levels 2 and 3), and skeletal alpha-actin levels were reduced in the septum and left ventricular free wall of plicated rats (level 3). beta-Myosin heavy chain levels were markedly reduced in peri-infarct regions of the left ventricular free wall, septum, and right ventricle in plicated rats at level 4, whereas myosin light chain-2v levels were reduced at levels 2 and 4 in the left ventricular free wall and at level 4 in the right ventricle. CONCLUSIONS: Plication of left ventricular aneurysm after infarction in the rat significantly reduced cardiac hypertrophy, improved cardiac function, and reduced the upregulation of pre-pro-atrial natriuretic peptide and both fetal and adult contractile protein isoforms associated with cardiac hypertrophy.     

Vitamin B12 and folate bioavailability from two prenatal multivitamin/multimineral supplements

In this crossover, single-blind study, the bioavailability of B12 and folate, fasting and postprandially, was measured in 30 pregnant women for two prenatal multivitamin/multimineral supplements (Stuartnatal Plus and Materna, Wyeth-Ayerst Pharmaceuticals, Philadelphia, PA) and a placebo. Blood samples were obtained before supplementation and at 1, 3, 6, and 8 hr after supplementation serum levels of the two vitamins were measured by radioimmunoassay. The maximum postabsorption serum level was multiplied by the total body plasma levels to obtain the total rate of body absorption. The absorption peak of both vitamins occurred at 3 hours after ingestion of a supplement. The total body absorption of the two vitamins was greater during fasting than it was postprandially. There was 30% greater B12 absorption for Stuartnatal Plus (371 +/- 56 vs. 285 +/- 34 pmol) and 33% for Materna (315 +/- 34 vs. 236 +/- 4 pmol, p < or = 0.05). Similarly, there was 117% greater folate absorption fasting for Stuartnatal Plus (163 +/- 15 vs. 75 +/- 15 nmol, p < or = 0.001) and 57% greater absorption for Materna (207 +/- 21 vs. 132 +/- 13 nmol, p < or = 0.01). Both vitamins were readily absorbed (within 3 hours) into the maternal hepatic portal circulation. The absorption of both vitamins was significantly less when ingested after the test meal than when fasting.     

Selecting antihypertensive therapy in the pregnant woman with diabetes mellitus

The choice of an antihypertensive agent for the pregnant woman with diabetes involves many factors. We seek to avoid adverse fetal effects while optimizing maternal outcome, both short- and long-term. This article examines the existing literature to define therapeutic goals of antihypertensive therapy during pregnancy as compared to the therapeutic goals of antihypertensive therapy in the setting of diabetes mellitus and to integrate this information for the treatment of pregnant women in whom diabetes mellitus and hypertension coexist.     

Takayasu arteritis in children

Takayasu arteritis (TA) is a large vessel vasculitis that usually affects young female patients during the second and third decades of life, but has been reported in children as young as 24 months of age. Aim of this report was to describe four children (two girls) with TA, as well as summarizing main published studies. The mean age at presentation of our cases was 11 years (range 8–15). Three patients were Caucasians and one Asian. Arterial hypertension was the commonest mode of presentation followed by systemic symptoms. Other related symptoms were due to ischemia and consisted of abdomen, chest, and limb pain. An abdominal bruit was noted in only one patient. Inflammation markers were always abnormal. Angiography was performed in all cases; left subclavian artery and common carotid artery were more frequently involved. Renal artery stenosis was observed in two patients. One boy was diagnosed as having an associated immune deficiency (Wiskott-Aldrich syndrome). Treatment modalities included prednisone (n = 4), methotrexate (n = 3), and mycophenolate mofetil (MMF) (n = 1). Surgery was required in two patients. Follow-up ranged from 3 to 10 years since diagnosis. In three cases antihypertensive drugs and methotrexate were stopped, and prednisone was reduced to 7.5 mg/day.     

Empowerment interventions,knowledge translation and exchange: perspectives of home care professionals,clients and caregivers

Background  

Few studies have examined empowerment interventions as they actually unfold in home care in the context of chronic health problems. This study aims to document the empowerment process as it plays out in interventions with adults receiving home care services.     

Is breast size a predictor of breast cancer risk or the laterality of the tumor?

The relationship of breast size both to breast cancer risk and to the laterality of the tumor was studied among 261 women diagnosed with breast cancer and 291 control subjects who were enrolled in the United States' Breast Cancer Detection and Demonstration Project from 1973 to 1980. Standardized measures of breast area were obtained by applying planimetry to bilateral screening mammograms taken four years before breast cancer was diagnosed in case subjects. The left breast was larger in 53 percent of women with breast cancer and in 60 percent of women in the control group; the difference in breast area by laterality was significant only among controls (P=0.01). To assess breast cancer risk, breast area was categorized by quartiles, with the lowest quartile being the referent group. Risk was increased minimally among women with the largest breast area (odds ratios = 0.9, 0.9, 1.2); however, the point estimates were not statistically significant and there was no evidence of a linear trend. Left-sided disease was diagnosed in 51 percent of women in the case group. Although the mean area of the breast with the malignancy did not differ significantly from the opposite breast, cancer developed in the larger breast of 57 percent of women with left- and 46 percent of women with right-sided disease. Breast size was associated with cancer of the left breast but not the right. However, these size differences were small since the area of the larger breast was less than 10 percent greater than the smaller breast among half of the case subjects. Further research is required to identify factors associated with the susceptibility of breast tissue to malignant transformation among women with unilateral disease.Dr Senie is with Memorial Sloan-Kettering Cancer Center, New York, NY, USA. Authors are also affiliated with the Centers for Disease Control and Prevention (Dr Saftlas), Atlanta, GA and the National Cancer Institute (Drs Brinton and Hoover), Bethesda, MD, USA. Address correspondence to Dr Senie, Breast Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York, 10021, USA.     

Physicians' Perceptions of the Changing Health Care System: Comparisons by Gender and Specialties

This study was designed to investigate physicians' perceptions of changes in the United States health care system impacting academic medicine, quality of care, patient referrals, cost, ethical and sociopolitical aspects of medicine. A survey was mailed in 1998 to 1,272 physicians (graduates of Jefferson Medical College between 1987 and 1992); 835 physicians (66%) responded. Results showed that a substantial majority (92%) believed that learning to work in a managed care environment should become an essential component of medical education. Physicians perceived that current changes impair physicians' autonomy (94%), and restrain physicians' freedom to provide optimal care (84%). A sizable majority (76%) endorsed patients' freedom to seek specialist care, and 55% believed that capitation reduces physicians' motivation for long-term monitoring of patients. The majority endorsed universal health coverage (80%), and agreed to support rather than resist the changes (62%). Only 18% hold a positive view of the changes in the future. The majority believed that medical education should prepare physicians to provide end-of-life care (92%), and that organized medicine should take a stand on social issues that can influence the well-being of society (79%). Only 34% endorsed the legalization of physician-assisted suicide. No gender differences were observed, but a few differences were found between generalists and specialists. Results can help in understanding physicians' perceptions of current changes in the United States health care system, and in providing guidelines for the development of educational programs to prepare physicians to face new challenges.