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Biomedical subjects

P Singer

Publications and source records attributed to P Singer.

At least 145 records · Page 8Linked to original sources

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↗

Growth, zinc and copper nutritional status of male premature infants with different zinc intake.

Zinc is an essential nutrient for growth and low intake can result in growth retardation. However, high zinc intake can affect copper metabolism. Therefore, data from a study of 10 male premature infants fed a cow's milk-based formula nonfortified with zinc (mean +/- SD = 1.4 +/- 0.1 mg X l-1) were compared with data of 10 similar infants fed the same formula fortified with zinc (4.1 +/- 0.3 mg X l-1). Growth, food intake, zinc and copper nutritional status were studied from 6 through 122 days of age. No differences in gain of weight, length and head circumference and in food intake were found. Serum zinc concentration was significantly (p less than 0.05) and hair zinc concentration was slightly higher in the infants fed the zinc-fortified formula at 122 days of age. Copper and ceruloplasmin concentrations in serum and hair copper concentration were similar in both groups at 122 days of age. The results suggest that feeding a formula nonfortified with zinc did not affect growth of male premature infants. Feeding a zinc-fortified formula on the other hand had no influence on copper nutritional status.

Copper↗

[Celiac plexus block. Modeling study using images of computerized tomography].

To determine possible risks of the blind approach to the coeliac plexus, a method for simulating Bridenbaugh's "blind" coeliac plexus block by CT slices and scoutviews was employed. This mathematical simulation of the blind approach to the coeliac plexus was applied to CT images of 50 patients suspected of upper abdominal tumours. This simulation revealed that the following organs would have been punctured inadvertently: Spinal nerves, liver, kidney, aorta, aortic wall, pancreas, lymphomas. The total percentage of misdirected punctures according to this simulation would have been 41%. The importance of the coeliac plexus block in patients with chronic pain is stressed. Literature studies and the results of the present study indicate that CT-guided or ultrasound-guided techniques should be preferred in coeliac plexus block whenever the facilities are available.

Abdominal Neoplasms↗

Ototoxicity of intraventricularly administered gentamicin in adult rabbits.

To determine whether daily intraventricular injection of gentamicin sulfate is ototoxic, adult male rabbits were given 0.2 ml of saline (group 1; n = 8) or 0.25 mg/kg of gentamicin sulfate in 0.2 ml of saline (group 2; n = 7) by intraventricular infusion once a day for 21 d. All rabbits were also given intramuscular gentamicin sulfate, 2 mg/kg, twice daily. Before and after antibiotic treatment, brainstem auditory evoked responses (BAERs) were recorded. During the experimental period, neurologic examinations were performed on all rabbits. After treatment, the animals were euthanized; brain tissue and cochleas were then removed for histopathologic examination. The ratios of neurologic abnormalities observed in group 1 and 2 animals, respectively, were 0/8 and 5/7; of abnormal BAERs, 0/8 and 5/7; of abnormal brain morphology, 2/5 and 6/6; and of abnormal cochlear morphology, 0/6 and 7/7. The electrophysiologic evidence of auditory deficit and the structural evidence of ototoxic insult are significantly associated (p less than or equal to 0.006) with intraventricularly administered gentamicin sulfate. These data suggest that intraventricular gentamicin should be used with caution.

Animals↗

Changes of blood pressure in spontaneously hypertensive rats dependent on the quantity and quality of fat intake.

The effect of diets rich or deficient in polyunsaturated fatty acids (PUFA) on blood pressure of spontaneously hypertensive rats (SHR) and normotensive Wistar rats (WR) was studied. The diets contained either sunflower oil (PUR-SOL), linseed oil (PUR-LIN), cod-liver oil or hydrogenated palm-kernel oil (PUFA-deficient) amounting to 15 or 3 weight percent of fat. They were started at weaning (4 weeks of age) for 22 weeks or prenatally one week before mating of the parents. During the development of hypertension in SHR, systolic blood pressure was decreased in animals of all dietary groups fed 15% fat when compared to SHR on normal food (pellets), i.e. independent of the various diets loaded, all diets containing 15% fat led to a marked delay in the onset of high blood pressure as compared to SHR on normal pellet food. After manifestation of hypertension, obviously a more differentiated effect on blood pressure could be shown in SHR in dependence on different amounts of PUFA loaded. In normotensive Wistar rats (WR) after feeding linseed oil or sunflower oil also a significant lowering in blood pressure could be observed in comparison to controls fed pellets. But after feeding cod-liver oil there was no decrease in blood pressure of normotensive Wistar rats, whereas palm-kernel oil resulted in a blood pressure lowering effect only at the later age of normotensive Wistar rats. Moreover, in SHR after prenatal feeding of a LA-rich, but also a PUFA-deficient diet the blood pressure lowering effect was more pronounced as compared to postnatal feeding of the diets. SHR fed a 15% fat diet showed a significantly lower body weight in comparison to SHR fed a 3% fat diet. In both dietary groups SHR were significantly smaller than SHR fed pellets. In WKY fed a 3% or a 15% fat diet the same body weight could be confirmed. Food intake in SHR fed a 3% fat diet ad libitum appeared higher than in SHR fed a 15% fat diet ad libitum. However, considering the uptake of energy no differences between the groups could be seen. Therefore, in SHR fed a 15% fat diet, body weight and blood pressure were lowest when compared with the other groups of SHR indicating that body weight in SHR might be nearly connected with blood pressure level.(ABSTRACT TRUNCATED AT 400 WORDS)

Age Factors↗