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Biomedical subjects

J A Buck

Publications and source records attributed to J A Buck.

27 records · Page 2Linked to original sources
PubMed1980

Involvement of phospholipids in polyunsaturated Fatty Acid synthesis in developing soybean cotyledons.

Developing soybean (cv. Dare) cotyledons harvested at 30 days after flowering were pulse-labeled with [1-(14)C]oleoyl-CoA. The metabolic interrelation of radiolabeled unsaturated fatty acids between the major glycerolipid classes was determined at various time intervals. At chase time zero, [(14)C]oleic acid accounted for 99.2% of the total glycerolipid radioactivity, and phospholipids contained 92% of the total incorporated radioactivity. With time, phospholipids were metabolized in triacylglycerol biosynthesis and radioactivity was detected in polyunsaturated fatty acids. The hypothesis that phospholipids were metabolic intermediates in polyunsaturated fatty acid biosynthesis was tested by comparing the theoretical and the actual amount of radiolabeled oleic acid that was associated with triacylglycerol as a function of time. The radioactive oleic acid found in triacylglycerol at various intervals was derived from phospholipids via a diacylglycerol intermediate. Assuming no phospholipid desaturation, the potential or theoretical amounts of [(14)C]oleic acid that could be transferred to triacylglycerol from phospholipids was defined by a system of differential equations. The results demonstrated that the decline in [(14)C]oleic acid from phospholipid after long chase intervals was equal to the total amount of radioactive unsaturated fatty acids found in neutral lipids. The difference between the theoretical and actual amounts of [(14)C]oleic acid present in triacylglycerol after long time intervals was equal to the amount of radioactivity present in polyunsaturated fatty acids. Based upon those findings in soybeans, the desaturation of oleic acid associated with phospholipids was highly probable.

Journal Article↗
PubMed1980

Systolic blood pressure responses during isometric contractions of large and small muscle groups.

The purpose of this study was to test for a difference between the systolic blood pressure responses to voluntary contractions of large and small muscle groups of the upper extremity. Systolic blood pressure was measured at approximately 20 sec intervals during sustained isometric contractions of the index finger adductors and handgrip muscles contracting at 40% of maximal voluntary contraction (MVC). Contractions were terminated when EMG activity exceeded 10% of maximal activity of selected accessory muscles or when the 40% MVC tension could no longer be held constant (+/-10%). The slopes of the regression lines representing systolic blood pressure responses to sustained isometric contraction of a small and large muscle group of the upper extremity were significantly different (p less than .001). Older theories that pressor responses are determined only by the % MVC and not by the mass of contracting muscle need to be reexamined.

Adult↗
PubMed1978

Studies on Genetic Male-Sterile Soybeans: I. Distribution of Plant Carbohydrate and Nitrogen during Development.

Soybeans (Glycine max [L.] Merr. cv. NC 69-2774) were used to study the nonstructural carbohydrate and nitrogen content of plant tissues, and nitrogenase activity throughout the development of male-sterile and male-fertile plants. Male-sterile plants set approximately 85% fewer pods plus seed than the male-fertile siblings and retained green leaves until a killing frost at 145 days after emergence. Reduced pod set caused increased carbohydrate accumulation in the leaf and root systems of male-sterile plants. Total carbohydrate in roots of male-sterile plants increased from 1.7 to 7.6 times that in the male-fertile roots. A high proportion (60 to 70%) of the male-sterile root carbohydrate was starch. Apparently, root starch was not metabolized by the male-sterile plants. Late in plant development per cent nitrogen was higher in the male-sterile soybean tissues. However, no difference was found in the ability of the nodulated root systems from either genotype to fix nitrogen.

Journal Article↗
PubMedDate not supplied

Behavioral health benefits in employer-sponsored health plans, 1997.

Data for 1997 show that three-quarters or more of employer-sponsored health plans continue to place greater restrictions on behavioral health coverage than on general medical coverage. The nature of these restrictions varies by plan type. Some improvement in the treatment of mental health/substance abuse (MH/SA) benefits in employer plans may be occurring, however. Comparisons with data from 1996 show that the proportion of plans with benefits for "alternative" types of MH/SA services, such as nonhospital residential care, has increased. Further, the proportion with special limitations on these benefits shows a modest decrease.

Data Collection↗
PubMedDate not supplied

Spending on mental health and substance abuse treatment, 1987-1997.

This paper is the result of an ongoing effort to track spending on mental health and substance abuse (MH/SA) treatment nationwide. Spending for MH/SA treatment was $85.3 billion in 1997: $73.4 billion for mental illness and $11.9 billion for substance abuse. MH/SA spending growth averaged 6.8 percent a year between 1987 and 1997, while national health expenditures grew by 8.2 percent.

Adult↗