No abstract

A feasibility study was instituted to determine if women with postmenopausal breast cancer would follow a low-fat diet (20% of kcal) for at least four months. Nineteen women, whose baseline food intake was 1,504 +/- 420 kcal with 56 +/- 16 g of fat, reported a decrease in fat intake to 21 +/- 6 g after two months of dietary intervention. Serum concentrations of cholesterol, HDL cholesterol, and estradiol were significantly reduced by the fifth month on the diet. We conclude that self-selected patients can adhere to a low-fat diet, and that serum cholesterol may serve as an indicator of dietary compliance.

The enzyme responsible for the direct phosphorylation of pyruvate during gluconeogenesis in Acetobacter xylinum has been purified 46-fold from ultrasonic extracts and freed from interfering enzyme activities. The enzyme was shown to catalyze the reversible Mge+ ion-dependent conversion of equimolar amounts of pyruvate, adenosine triphosphate (ATP), and orthophosphate (Pi) into phosphoenolpyruvate (PEP), adenosine monophosphate (AMP), and pyrophosphate (PP). The optimal pH for PEP synthesis was pH 8.2; for the reversal it was pH 6.5. The ratio between the initial rates of the reaction in the forward and reverse directions was 5.1 at pH 8.2 and 0.45 at pH 6.5. The apparent K, values of the components of the system in the forward reaction were: pyruvate, 0.2 mM; ATP, 0.4 mM; Pi, 0.8 mM; Mg2+, 2.2 mM; and for the reverse reaction: PEP, 0.1 mM; AMP, 1.6 ,uM; PP, 0.067 mM; Mg2+, 0.87 mm. PEP formation was inhibited by AMP and PP. The inhibition by AMP was competitive with regard to ATP (Ki = 0.2 mM). The reverse reaction was in-211 Vol. 104,No. 1 Printed in U.S.A.

Tomato fruit (Lycopersicum esculentum Mil) from green, pink, and red stages were assayed for changes in the activity of ribulose diphosphate carboxylase and oxygenase, phosphoenolpyruvate carboxylase, changes in the levels of glycolate and respiratory gas exchange. The ribulose diphosphate carboxylase activity decreased as the fruit ripened. By comparison, the ribulose diphosphate oxygenase activity increased during the transition from the green to the pink stage, and declined afterward. The changes in the endogenous glycolate levels and the respiratory gas exchange, as observed at different stages of ripening, resembled the changes in the ribulose diphosphate oxygenase activity. The utilization of glycolate in further metabolic activity may result in the formation of peroxidases required for the onset of ripening.

No abstract

Of 514 Israeli women 4-5 months pregnant, 200 who were non-anemic (Hb 11 gm/100 ml or higher) took a daily supplement of ferrous sulfate (100 mg elemental iron). The 160 who remained on this regimen showed, as a group, significantly less reduction in hemoglobin levels than 180 non-anemic women who did not wish to take the supplement. Forty of the 200 women either dropped out or were shifted to other treatment regimens because they developed anemia after the fifth month. (Am J Public Health 1981; 71:736-739.)

This paper presents a trend-free regression model for analyzing the effect of changes in food intake on disease specific mortality rates. The statistical effect of changes in food consumption of the Israeli population during 1949 to 1977 on concurrent mortality rates from cancer, heart disease, peptic ulcer, and diabetes mellitus were investigated by the suggested model. The regression analyses reveal the following: 1) The major statistical effects of progressive dietary changes (during 28 yr) on mortality rates lagged by 1 or 2 yr. 2) None of the variables was consistently and statistically significantly related to cancer mortality. 3) Vitamin A was consistently in statistically significant negative association with mortality rates. This suggests that increased consumption of vitamin A may prove to reduce mortality rates due to heart disease and peptic ulcer. 4) All the investigated mortality rates were in statistically significant positive association with increasing total fat consumption. Mortality rates of ischemic heart disease as well as of hypertensive and cerebrovascular diseases were in positive association with both plant fat and animal fat. These findings suggest that reduced total fat intake may prove to reduce the investigated mortality rates. 5) Diabetes mellitus was in statistically significant inverse association with the average per capital consumption of fruits and vegetables. Our results suggest that increased carbohydrate consumption may reduce diabetes mellitus mortality. The above hypotheses derived from the model and the general utility of the model may be demonstrated by studies of data from other countries.

No abstract