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Biomedical subjects

P Singer

Publications and source records attributed to P Singer.

At least 163 records · Page 9Linked to original sources

Serum triglycerides and HDL cholesterol from SHR after evening primrose oil and other polyunsaturated fats.

Spontaneously hypertensive rats (SHR) were fed diets enriched with evening primrose (EPO), sunflower (SO) and linseed oils (LO) as well as palm kernel fat (PKF), the latter being deficient in polyunsarated fatty acids (PUFA). In SHR fed EPO serum triglycerides were lowest and HDL1 cholesterol was highest as compared to the other groups of animals. Total cholesterol was not different. The data suggest that - as with blood pressure - serum lipids and lipoproteins might be influenced most effectively by EPO in comparison to other polyunsaturated fats.

Administration, Oral↗

Different changes of n-6 and n-3 fatty acids in adipose tissue from spontaneously hypertensive (SHR) and normotensive rats after diets supplemented with linolenic or eicosapentaenoic acids.

In spontaneously hypertensive (SHR) and normotensive rats of the Wistar-Kyoto (WKY) and Wistar-Schönwalde (WSCHOE) strain, diets supplemented with n-3 fatty acids of different chain length (alpha-linolenic acid, LNA--C 18:3, n-3 with linseed oil and eicosapentaenoic acid, EPA--C 20:5, n-3 with cod liver oil) were fed over a period of 22 weeks. After the LNA-rich diet, among the long-chain n-3 fatty acids EPA in epididymal adipose tissue remained unchanged, whereas docosapentaenoic (DPA) and docosahexaenoic acids (DHA) fell. The n-6 fatty acids linoleic (LA) and arachidonic acid (AA) both appeared decreased. After the EPA-rich diet, all n-3 fatty acids, i.e. not only EPA, DPA and DHA, but also LNA were augmented when compared with controls fed commercially available pellets. Among the n-6 fatty acids LA was extremely depressed, whereas AA appeared increased. The p/s-ratio was elevated after the LNA-rich diet, but decreased after the EPA-rich diet. The data indicate a differential effect of dietary n-3 fatty acids of different chain length on the supply of other n-3 fatty acids, of LA and AA as well as on the p/s-ratio in adipose tissue of rats. Blood pressure was not influenced by either diet in either SHR or in both normotensive strains of rats.

Adipose Tissue↗

Slow desaturation and elongation of linoleic and alpha-linolenic acids as a rationale of eicosapentaenoic acid-rich diet to lower blood pressure and serum lipids in normal, hypertensive and hyperlipemic subjects.

In normal, hypertensive and hyperlipemic subjects, diets supplemented with linoleic acid (LA) or alpha-linolenic acid (LNA) resulted in an increase of the corresponding fatty acids in serum lipids. However, their C20-derivatives, the prostaglandin precursors arachidonic acid (AA) and eicosapentaenoic acid (EPA), respectively, were not or only slightly augmented. On the other hand, an EPA-rich diet produced a marked increase of this fatty acid, especially in cholesterol esters. After this diet the decreases of blood pressure and serum lipids were more pronounced when compared with LA- and LNA-rich diets containing a 20-fold higher dose of the polyunsaturated fatty acids. The slow formation of AA and EPA from LA and LNA seems to be a characteristic finding in humans, being different from preferred laboratory animals, for instance, rats. This observation was independent of the presence of risk factors, like arterial hypertension or hyperlipoproteinemia (HLP).

Adult↗

Blood pressure lowering effect of eicosapentaenoic acid-rich diet in normotensive, hypertensive and hyperlipemic subjects.

A mackerel diet or a herring diet in which two cans of fish fillet were consumed daily over 2 weeks within a prescribed regimen, in a crossover design, were given to 15 normotensive volunteers, 14 patients with mild essential hypertension and eight patients with type IV and V hyperlipoproteinemia (HLP). In normotensives a markedly lower systolic and diastolic blood pressure at the end of the period on the mackerel diet could be observed, whereas in hypertensive and hyperlipemic subjects only systolic blood pressure was significantly decreased. After the herring diet, which served as control, changes in blood pressure were of a minor degree.

Adult↗

Stability of ribosomal protein mRNA and translational feedback regulation in Escherichia coli.

It was previously observed that the stability of ribosomal protein (r-protein) mRNA in Escherichia coli decreases under the conditions where its translation is feedback inhibited by repressor r-protein. We have now demonstrated that the stability of mRNA for r-proteins S13, S11 and S4 increases in a strain carrying a mutation in the gene for S4, a translational repressor regulating these r-proteins. The results confirm the previous observations that translational repression increases the decay rate of r-protein mRNA, and in addition, show that the half-life of S13-S4 r-protein mRNA in cells growing under ordinary conditions is significantly shorter than its inherent stability would predict, due to the operation of translational feedback regulation.

Escherichia coli↗

Blood pressure- and lipid-lowering effect of mackerel and herring diet in patients with mild essential hypertension.

Fourteen male patients with mild essential hypertension were put on a mackerel and herring diet within a prescribed isocaloric regimen in a cross-over design for 2 weeks. After mackerel diet eicosapentaenoic acid (EPA-C20:5, n-3) appeared more in cholesterol esters (1.7-11.0%), whereas docosahexaenoic acid (DHA-C22:6, n-3) was predominantly incorporated into serum triglycerides (1.0-8.3%). After herring diet, which contained half as much EPA and DHA, their increase was of minor degree. After mackerel diet serum triglycerides, total cholesterol, LDL cholesterol and lecithin cholesterol acyl transferase (LCAT) activity were significantly decreased (by 28%, 9%, 14% and 14%, respectively), returning to the initial levels 3 months later. On the contrary, HDL cholesterol appeared significantly increased (by 12%). After herring diet the differences were not significant. Serum sodium was significantly lower (by 2%) at the end of the mackerel diet as compared to the initial values. On the other hand, uric acid in serum appeared transiently increased (by 24%) at the end of both dietary periods. A significant decrease (by 8%) in casual systolic blood pressure, measured in recumbent position, could be observed only at the end of the mackerel period. Moreover, the level of systolic and diastolic blood pressure before and during a standardized psychophysiological stress test was significantly lower after mackerel diet. Nevertheless, the increments after stress were similar. Plasma renin activity was increased (by 64%) after mackerel diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Influence on serum lipids, lipoproteins and blood pressure of mackerel and herring diet in patients with type IV and V hyperlipoproteinemia.

Eight patients with type IV and V hyperlipoproteinemia were put on a mackerel and herring diet of an isocaloric regimen for 2 weeks, in a cross-over design. At the end of the dietary periods a predominant increase of eicosapentaenoic acid (EPA - C20:5, n-3) in cholesterol esters and of docosahexaenoic acid (DHA - C22:6, n-3) in serum triglycerides, being more pronounced after mackerel as compared to herring diet, could be confirmed. After mackerel diet serum triglycerides and total cholesterol were significantly lower, returning to basal levels 3 months later. High density lipoprotein (HDL) cholesterol appeared slightly increased after mackerel diet and decreased to initial values thereafter. After herring diet, which contained half as much EPA as compared to mackerel diet, the differences were minor. The decline of free fatty acids (FFA) and insulin at the end of the mackerel period reached the level of significance 60 min and 120 min, respectively, after glucose load. A significantly lower systolic blood pressure in recumbent and upright position after the mackerel period could be found, whereas diastolic pressure and blood pressure after herring diet remained unchanged.

Adult↗

Maintenance of psychosocial attitudes in medical students.

Attitudes of medical students towards the psychosocial aspects of illness is of serious concern to medical educators. It is thought that medical students are overwhelmingly disease-oriented and not sufficiently sensitive to the role of the psychological, emotional, sociological and economic factors in the etiology and management of illness. In the present study the ATSIM (Attitudes Towards Social Issues in Medicine) was presented to third year medical students and compared with their responses obtained 2 years previously when they were first year students. The data suggest that third year medical students have positive attitudes towards certain psychosocial issues (the importance of social factors as determinants of health or illness, the role of preventive medicine in maintaining health, the role of physician-patient interactions in patient care). These attitudes were positive during the students' first year and have been maintained during the course of medical school. These finding are contrary to previous studies which indicate a deterioration in attitudes during the course of medical school.

Adult↗

[Dosimetry in computerized tomography].

During CT, the surface dose increases towards the centre of the axis of rotation. Measurements on 35 patients and theoretical considerations indicate a hyperbolic relationship between the axis of rotation and the surface dose.

Adult↗

Studies on the whole-body distribution of 14C-trithioparamethoxyphenylpropene in mice.

The study was undertaken to map the whole body distribution of trithioparamethoxyphenylpropene, TPMPP, a substance which is believed to stimulate salivary secretion. Two series of male and pregnant female mice were given 4.3 microCi 14C-TPMPP by gastric intubation. The animals were sacrificed at various intervals, embedded in CMC and frozen. Sections were taken from all levels and wholebody autoradiography performed. Four hours after administration the isotope was located in the intestines, liver, gall bladder, kidney and urinary bladder. High concentrations of the isotope persisted for 12 h with the exception of the kidney which showed decreasing concentrations after 4 h. The isotope was not found in the fetus or placenta. 24 h after administration no activity could be detected in any of the above mentioned organs. If TPMPP plays a role in salivary secretion this must be secondary as it was not found in the salivary glands, or nerve structures.

Anethole Trithione↗