Hamsters and guinea pigs differ in their plasma lipoprotein cholesterol distribution when fed diets varying in animal protein, soluble fiber, or cholesterol content.

There were two objectives to these studies: 1) to compare the lipoprotein cholesterol distribution in two animal models in response to different dietary treatments and 2) to assess whether the hypercholesterolemia induced by high cholesterol intake could be reversed by consumption of vegetable-protein and/or dietary fiber. Guinea pigs, which carry the majority of plasma cholesterol in LDL, and hamsters, with a higher distribution of cholesterol in HDL, were evaluated in three different studies. In Study 1, animals were fed semi-purified diets for 4 wk with proportions of 60:40, 20:80 or 0:100 (w/w) of casein/ soybean protein. Hamsters and guinea pigs that consumed 100% soybean protein had lower plasma total cholesterol (TC) than those fed diets containing casein (P < 0.01). In Study 2, three doses of dietary pectin (2.7, 5.4, or 10.7 g/100g) added in place of cellulose were tested. Intake of 10.7 g/100 g pectin resulted in the lowest plasma TC concentrations for both species (P < 0.01). Although the TC lowering was similar in studies 1 and 2, the lipoprotein cholesterol distribution differed. Whereas the differences in plasma cholesterol were in LDL in guinea pigs, hamsters exhibited differences in both non-HDL and HDL cholesterol. In study 3, animals were fed 100% soybean protein, 10.7 g/100 g pectin, and three doses of dietary cholesterol: 0.04, 0.08, or 0.16 g/100 g, which is equivalent to 300, 600, or 1,200 mg/d in humans. Guinea pigs and hamsters had the highest plasma LDL and hepatic cholesterol concentrations when they consumed 0.16 g/100 g of cholesterol (P < 0.01). However, intake of 0.08 g/100 g of cholesterol resulted in lower plasma LDL cholesterol concentrations than did consuming high animal protein (60:40 casein/ soy) or low soluble fiber (2.7 g/100 g). Relatively high levels of dietary cholesterol combined with vegetable protein and soluble fiber resulted in desirable lipoprotein profiles in animal models that significantly differ in their lipoprotein cholesterol distribution.     

Effacement of the fetal cisterna magna in association with myelomeningocele

The cisterna magna is effaced in association with myelomeningocele. The authors retrospectively investigated the size of the fetal cisterna magna as a predictor of fetal myelomeningocele in 67 pregnant women (17-38 menstrual weeks) referred for prenatal sonography because of an elevated serum alpha-fetoprotein level (n = 61) or a suspicion of fetal ventriculomegaly on previously obtained sonograms (n = 6). Twenty fetuses had myelomeningocele, 14 had isolated ventriculomegaly, and 33 were normal. A normal-sized cisterna magna (range, 4-9 mm in depth) was present in all normal fetuses. In 19 of 20 fetuses with myelomeningocele, the views of the posterior fossa were adequate, and in each of these the cisterna magna was effaced (n = 18) or very small (n = 1). The cisterna magna was effaced in five of 13 (38%) fetuses with isolated ventriculomegaly in whom the posterior fossa was adequately imaged. Although effacement of the cisterna magna is a nonspecific finding, the high negative predictive value of this sign is useful during routine screening of the fetal neural axis.     

Secondary neoplastic infiltration of the myocardium diagnosed by two-dimensional echocardiography in seven cases with anatomic confirmation

In seven patients with different types of neoplasm, secondary myocardial infiltration was diagnosed in vivo by two-dimensional echocardiography and confirmed by direct inspection. In all patients, clinical and electrocardiographic findings were suggestive but nonspecific for myocardial involvement. Two patients had cardiac tamponade and three had pericardial effusion. In three patients, the echocardiographic diagnosis made it possible to plan specific therapy. Clinical, electrocardiographic and echocardiographic aspects are discussed. A two-dimensional echocardiographic examination should be performed in all patients when cardiac metastatic involvement is suspected from clinical electrocardiographic findings, because the in vivo diagnosis of such a condition may have important therapeutic implications for such patients.     

Demographic characteristics and prevalence of serologic markers among donors who use the confidential unit exclusion process: the Retrovirus Epidemiology Donor Study

BACKGROUND: Most blood centers utilize a confidential unit exclusion (CUE) process, intended to reduce the risk of transfusion-associated infectious diseases by allowing high-risk donors confidentially to exclude their blood from use for transfusion. The effectiveness of this method remains controversial. STUDY DESIGN AND METHODS: Confirmatory or supplemental test results for antibodies to human immunodeficiency virus, human T-lymphotropic virus type I, and hepatitis C virus, as well as hepatitis B surface antigen and syphilis and screening test results for antibodies to hepatitis B core (antigen) and alanine aminotransferase levels were obtained for approximately 1.8 million units donated during 1991 and 1992 at five blood centers within the United States. The prevalences of these infectious disease markers in units that the donors confidentially excluded (CUE+) and units that the donors did not exclude (CUE-) were calculated and examined within demographic subgroups. RESULTS: Units that were CUE+ were 8 to 41 times more likely to be seropositive for antibodies to human immunodeficiency virus and hepatitis C virus, hepatitis B surface antigen, and syphilis and three to four times more likely to react for antibody to hepatitis B core (antigen) or to have elevated alanine aminotransferase levels than units that were CUE- (p < 0.001). The positive predictive value of CUE (the percentage of CUE+ units that were confirmed seropositive for any marker) was 3.5 percent, and the sensitivity of CUE (the percentage of confirmed-seropositive units that were CUE+) was 2.3 percent. CONCLUSION: The current CUE process has low sensitivity and apparently low positive predictive value, and in many cases, it appeared that donors misunderstood it. Yet, CUE was not a “random process,” as CUE+ units were more likely to be seropositive for any infectious disease marker than CUE- units. This suggests that efforts to improve the CUE system may be warranted. As risk factors for transfusion-transmitted infection become more difficult to identify by history-based screening, however, such efforts may have limited effect.     

Total radical trapping antioxidant potential (TRAP) and exercise

The relationship between physical activity, physical fitness and total radical trapping antioxidant potential (TRAP) was examined in the Northern Ireland Health and Activity Survey. This was a cross-sectional population study (n = 1600) using a two-stage probability sample of the population. TRAP was calculated using the sum of the individual serum antioxidant concentrations (urate, protein thiols, ascorbate, alpha tocopherol and bilirubin) multiplied by their respective stoichiometric values. Physical fitness was determined by estimation of VO2max by extrapolation from submaximal oxygen uptake, and physical activity was recorded by computer-assisted interview. Mean serum TRAP concentrations were significantly higher in males (653 +/- 8.2 mumol/l, mean +/- SEM) compared to females (564 +/- 8.0 mumol/l) (p < 0.0001). Both male and female smokers had significantly lower TRAP values than non-smokers (males p < 0.0001, females p = 0.02). In females, there was a positive relationship of TRAP with age (p < 0.001) and body mass index (p < 0.001) but a negative relationship with physical fitness (p < 0.05). The known beneficial effects of exercise and activity do not appear to be directly mediated through increased antioxidant status.      

Dynamic Left Ventricular Outflow Tract Obstruction During Myocardial Ischemia in Mitral Valve Prolapse Syndrome

Systolic anterior motion of the mitral valve (MV) with dynamic left ventricular (LV) outflow tract obstruction is a well known phenomenon in hypertrophic cardiomyopathy, or other forms of hyper-dynamic LV function associated with hypovolemic states, or LV hypertrophy. We report three patients with MV prolapse in the absence of the above predisposing factors, who developed an LV outflow dynamic gradient during acute transient myocardial ischemia. An interaction between structural abnormalities of the mitral apparatus and ischemia-dependent LV shape deformity most likely accounted for the outflow gradient.