The pulmonary venous systolic flow pulse--its origin and relationship to left atrial pressure.

OBJECTIVES: The purpose of this study was to determine the origin of the pulmonary venous systolic flow pulse using wave-intensity analysis to separate forward- and backward-going waves. BACKGROUND: The mechanism of the pulmonary venous systolic flow pulse is unclear and could be a "suction effect" due to a fall in atrial pressure (backward-going wave) or a "pushing effect" due to forward-propagation of right ventricular (RV) pressure (forward-going wave). METHODS: In eight patients during coronary surgery, pulmonary venous flow (flow probe), velocity (microsensor) and pressure (micromanometer) were recorded. We calculated wave intensity (dP x dU) as change in pulmonary venous pressure (dP) times change in velocity (dU) at 5 ms intervals. When dP x dU > 0 there is a net forward-going wave and when dP x dU < 0 there is a net backward-going wave. RESULTS: Systolic pulmonary venous flow was biphasic. When flow accelerated in early systole (S1), pulmonary venous pressure was falling, and, therefore, dP x dU was negative, -0.6 +/- 0.2 (x +/- SE) W/m2, indicating a net backward-going wave. When flow accelerated in late systole (S2), pressure was rising, and, therefore, dP x dU was positive, 0.3 +/- 0.1 W/m2, indicating a net forward-going wave. CONCLUSIONS: Pulmonary venous flow acceleration in S1 was attributed to a net backward-going wave secondary to a fall in atrial pressure. However, flow acceleration in S2 was attributed to a net forward-going wave, consistent with propagation of the RV systolic pressure pulse across the lungs. Pulmonary vein systolic flow pattern, therefore, appears to be determined by right- as well as left-sided cardiac events.

A comparison of desflurane and isoflurane in patients undergoing coronary artery surgery.

Animal studies indicate that desflurane and isoflurane have similar hemodynamic effects when administered in equipotent anesthetic concentrations. The authors compared desflurane and isoflurane, used as primary anesthetics for patients undergoing elective coronary artery bypass surgery whose left ventricular ejection fractions were greater than 0.34. After induction of anesthesia with thiopental (dose 180 +/- 45 mg [mean +/- standard deviation]) and fentanyl, 10 micrograms.kg-1, either desflurane or isoflurane was administered to maintain systolic blood pressure within 70-120% of, and heart rates less than 120% of, the patients' average preoperative values. If adjusting the end-tidal anesthetic concentration within the range of 0-2.0 MAC could not maintain these predefined hemodynamic limits, additional fentanyl or vasoactive drugs were used. Induction and maintenance of anesthesia was accompanied by a significant decrease in mean arterial pressure in both groups (desflurane 97 +/- 12 mmHg at control, decreasing to 71 +/- 5 mmHg during skin preparation; isoflurane 95 +/- 9 mmHg at control, 74 +/- 9 mmHg during skin preparation). One minute after sternotomy, mean arterial pressure in the isoflurane group had returned to control, 97 +/- 9 mmHg, which was significantly greater than in the desflurane group, 87 +/- 12 mmHg. Systolic arterial pressure was also significantly greater in the isoflurane group 1 min after intubation, during skin preparation, and 1 min after sternotomy. Otherwise, the hemodynamic effects of these volatile agents were similar. There were no differences between groups in the incidence of ECG changes indicative of myocardial ischemia prior to cardiopulmonary bypass, perioperative myocardial infarction, or perioperative mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Characteristics of a random sample of emergency food program users in New York: I. Food pantries.

Food pantry users throughout New York State were studied and many demographic differences found between New York City and Upstate New York respondents. Seven percent of households had no income and median income as percent of the poverty level was 59 percent. Slightly more than 40 percent were spending over 60 percent of their incomes on housing. The data from this survey, the first in New York State to employ a random sampling design, demonstrate a sizable gap between household needs and available resources.

Characteristics of a random sample of emergency food program users in New York: II. Soup kitchens.

A random sample of soup kitchen clients in New York City was studied and specific comparisons made on various parameters including homelessness. Compared with the general population of low income persons, soup kitchen users were overwhelmingly male, disproportionately African-American, and more likely to live alone. The homeless (41 percent of the sample) were less likely to receive food stamps or free food, or to use food pantries. Fewer of them received Medicaid or had health insurance. Forty-seven percent had no income in contrast to 29 percent of the total sample.

Reduced serum cholesterol with dietary change using fat-modified and oat bran supplemented diets.

A low-fat, low-cholesterol diet and oat bran supplementation for treatment of hypercholesterolemia were studied for their effectiveness in lowering blood lipids and their impact on dietary intake. Seventy-one free-living men and women with hypercholesterolemia (serum cholesterol greater than 75th percentile) were randomly assigned to one of the following four groups: low-fat, low-cholesterol diet (LFLC); low-fat, low-cholesterol diet plus 50 gm/day oat bran (LFLC + OB); 50 gm/day oat bran supplemented diet (OB); or 42.5 gm/day processed oat bran (ready-to-eat cereal containing beta-glucan concentrated from oat bran) (POB). Subjects assigned to regimens OB and POB were requested to add the oat supplement without making additional changes in their diet. Serum cholesterol and high-density lipoprotein cholesterol analyses were performed at 4-week intervals, and diet records were assigned and analyzed. All groups experienced significant decreases in cholesterol from original levels (p less than .05). The average decrease in total serum cholesterol varied from 10% to 17%, with no significant differences among the four groups. High-density lipoprotein cholesterol concentrations decreased in all groups except group 4, in which there was a slight increase; however, no differences were found between groups. Energy, fat, and cholesterol intakes decreased in all groups, suggesting that displacement of higher fat foods from the diet may be one of the many mechanisms whereby oat supplements lower serum cholesterol. In addition, all groups reduced their intakes of calcium, copper, folic acid, and potassium from marginal levels at the beginning of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

The contribution of enrichment and fortification to nutrient intake of women.

A volunteer group of 162 women aged 25 to 49 years was recruited from three suburban supermarkets in central New York state. The women completed 3-day food records, which were analyzed for total nutrient intake and contribution of eight nutrients from three sources: (a) nutrients naturally present in food, (b) enriched/fortified foods with a standard of identity (FF + SI), and (c) fortified foods without standards of identity (FF-SI). Subjects were placed into study groups of high-, moderate-, and low-fortifiers on the basis of frequency of intake of highly fortified foods (FF-SI) which, unlike FF + SI, are not staple foods and may represent selective dietary nutrient addition by the consumer. For all groups, mean intakes of riboflavin, niacin, and vitamins A and C were greater than 100% of the RDAs without nutrient addition. Mean thiamin intake met the RDA only when the nutrient addition from FF + SI was included. Mean intakes of iron, calcium, and vitamin D were all below the RDA even when all sources of intake were included. No significant differences between study groups were found for total nutrient intake. With the exceptions of vitamin C, vitamin D, and calcium, high- and moderate-fortifiers had significantly greater (p less than .01) nutrient intake from fortification. Low-fortifiers had significantly greater (p less than .05) intake from naturally occurring vitamins A and C than high-fortifiers.

Nutritional status of children and teenagers in relation to vitamin and mineral use.

The use of vitamin and mineral supplements by children and teenagers in NHANES II was examined for relationships with demographic variables, dietary intakes from food, and biochemical measures of nutritional status and was compared with use reported in other nutrition studies. The number of regular supplement users decreased with age until about age 13, when the percentage of boys using supplements plateaued at about 10% but the percentage of use among girls increased. In general, children were more likely to receive supplements if they came from families with a household head who was white and better educated. Children from the lowest income level (poverty index less than 1.0) received supplements less frequently than other children. Among preschool children, supplement use by mothers and children was highly correlated. For most age groups, supplement users consumed more vitamin C from food than non-users. Users of supplements had higher mean serum levels of vitamins A and C and a lower incidence of low serum values for those nutrients than non-users. Fewer children took iron supplements than vitamin supplements, but most of the iron supplements were taken as part of a multiple vitamin plus iron preparation. There were no significant differences in either mean values for indexes of iron status or the percentage of low iron status values between children who received supplemental iron and those who did not.

Effect of dietary eggs and ascorbic acid on plasma lipid and lipoprotein cholesterol levels in healthy young men.

The effects on plasma lipid levels of increased ingestion of whole eggs and of ascorbic acid (AA) were investigated in 40 healthy, free-living men, aged 21 to 35 yr. Ten subjects were assigned to each of four groups which included the following regimens in combination with the usual daily diet: EGGS group, 3 eggs + placebo; AA group, 2 g ascorbic acid; EG AA group, 3 eggs + 2 g ascorbic acid; CONTROL group, placebo only. Fasting blood was sampled at 2-wk intervals during a 6-wk experimental period and during a 4-wk postexperimental period. Dietary cholesterol intake increased from a mean (+/-SD) of 412 (+/-200) mg/day during the preexperimental period to 975 (+/-134) mg/day on the experimental egg diet (p less than 0.001). Mean changes in plasma lipids in the eGGS and AA groups were not statistically significant. Considerable variability in individual responses was observed. In the EGAA group, significant increases in total cholesterol (18.3 +/- 6.4 mg/dl) and low-density lipoprotein cholesterol (10.0 +/- 6.4 mg/dl) at 4 wk were observed. Analysis of variance indicated significant interaction between the effects of eggs and AA. A possible synergistic relationship between these two dietary factors is suggested.

Relationship between iron status and exercise in male and female growing rats.

Weanling rats of both sexes were fed for 6 weeks diets containing 42, 17 or 7 ppm iron to produce adequate, moderately deficient and severely deficient iron status, respectively. At each level of iron, rats were either sedentary, trained regularly on a treadmill or housed in activity wheel cages. The moderately and severely deficient rats of both sexes which were exercised regularly had slightly greater liver non-heme iron stores and slightly higher hematologic values than sedentary rats. In the adequately nourished rats, exercise enhanced iron stores but had no effect on hematologic status. Rats were tested for physical work performance by a graded treadmill test every 2 weeks. Compared to adequately nourished rats, moderately iron-deficient rats had lower liver iron stores and slightly lower hematological values, but growth rate, heart size, spontaneous activity and treadmill performance were unaffected by the deficiency. Severely deficient rats, compared to adequately nourished rats, had depressed growth rate (82%), cardiac hypertrophy (14%) and lower hematologic values. Treadmill performance of male rats, in contrast to females, was more negatively affected by severe iron deficiency.

Influence of a nutrition education program (EFNEP) on infant nutrition in East Harlem.

An assessment of the effectiveness of aides working in the Expanded Food and Nutrition Education Program (EFNEP) to improve the nutritional status of infants was conducted with a group of 118 infants attending a well-baby clinic in a low-income area of New York City. In addition to clinic care, the fifty-seven study infants received home visits from a nutrition aide whose role was to reinforce nutritional advice received at the clinic. The sixty-one control infants received only regular clinic care. The benefits of having an aide were suggested by three observations: Reduction in the practice of introducing whole cow's milk to young infants, familiarizing older infants with a variety of foods, and reducing the prevalence of iron-deficiency anemia. Few of the differences between study and control infants achieved statistical significance, although trends consistently indicated that the presence of aides was beneficial. The problems of assessing the effectiveness of nutrition education programs with healthy infants are discussed.

Infant feeding practices in East Harlem.

Infant feeding practices among low-income infants in East Harlem were surveyed prior to undertaking a nutrition education program. Data were obtained from 24-hr. recalls on 153 infants seen in a well-baby clinic. Intakes of energy, protein, fat, ascorbic acid, iron, and sodium showed wide variations among infants of similar ages. Nutrient intakes were similar for black and Puerto Rican infants, although some ethnic differences were observed in the types of milk and solid foods consumed. Black infants received formula for a longer period, while Puerto Rican infants were transferred to whole cow's milk at a younger age. In contrast black infants were introduced to table foods earlier.