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Biomedical subjects

P Singer

Publications and source records attributed to P Singer.

At least 37 records · Page 2Linked to original sources

Bioethics and the limits of tolerance.

Since 1989 there has been an ongoing controversy about the limits of public discussion of bioethical issues in the German-speaking world. While a number of scholars have been involved, Peter Singer and Helga Kuhse have been the principal targets of those seeking to limit bioethical debates. Those who have supported silencing discussion of certain issues have argued that such public discussion leads to a loss of freedom. In the article we argue that toleration is not based on subjectivism but rather on reason. Furthermore, the efforts to suppress debate are often based on a failure to understand our position. Such efforts at suppression also rest on an elitist view of society that must assume that the general public cannot debate such topics.

Attitude

AIDS presenting as progressive multifocal leukoencephalopathy with clinical response to zidovudine.

Progressive multifocal leukoencephalopathy (PML) due to JC virus can be the initial manifestation of AIDS. A 40-year-old man seropositive for HIV-1 presented with aphasia, hemiparesis, and hemianopsia, and with magnetic resonance imaging of the brain typical of PML. He quickly became bed bound, incontinent, and mute. The diagnosis of PML was established by histopathology in a brain biopsy with positive immunocytochemistry for polyomavirus capsid proteins, and detection of JCV DNA by polymerase chain reaction using JCV-specific primers. High dose zidovudine therapy was initiated (1200 mg/day). Within two weeks the patient began to respond, and after three months he was able to walk and care for himself and was discharged. He lived for two years from the onset of PML. While cytarabine has been the drug most widely used for PML treatment, this is the second confirmed case with apparent response to zidovudine. High dose zidovudine may benefit some previously untreated AIDS patients with onset as PML.

AIDS Dementia Complex

A comparison of 6 months' compliance of patients with rheumatoid arthritis treated with tenoxicam and naproxen. Use of patient computer data to assess response to treatment.

OBJECTIVE: To assess longterm compliance in patients with rheumatoid arthritis (RA) of 20 mg tenoxicam or 500-1000 mg naproxen taken daily and to evaluate patient computer data collection. METHODS: Three hundred and seven patients were treated in a double blind, randomized multicenter study for 6 months. The first 4 weeks of treatment data were collected daily via patient operated computers in parallel with standard assessment at weekly visits to the clinics. RESULTS: Daily patient data collection was more sensitive than weekly clinical assessments. Six months' compliance was 62% for tenoxicam and 67% for naproxen with comparable rates of withdrawal due to lack of efficacy or adverse drug experiences in both groups. The spectra of adverse drug events found were very similar for both drugs but the rates were higher than in short term studies. CONCLUSION: Daily computer data collection by patients is superior to classical clinical evaluation in drug studies. The longterm compliance of tenoxicam and naproxen are comparable when treating patients with RA.

Age Distribution

Voluntary euthanasia and the nurse: an Australian survey.

This article presents the results of a survey of the attitudes and practices of nurses in Victoria with regard to requests for active or passive help in dying from patients who were suffering from a terminal or incurable disease. Questionnaires were sent to 1942 nurses who had been selected at random, 943 nurses (49%) of whom returned completed questionnaires. The survey indicates that a clear majority of those who responded to the questionnaire support active voluntary euthanasia. Many nurses have collaborated with doctors in the provision of active voluntary euthanasia and a few have acted without consulting a doctor. Seventy-eight per cent of nurses thought the law should be changed to allow doctors to take active steps to bring about a patient's death under some circumstances; and 65% of nurses indicated that they would be willing to collaborate with doctors in the provision of active voluntary euthanasia if it were legal.

Adult

Hypercaloric glycerol in injured patients.

BACKGROUND: This study investigates the effects of glycerol as a fuel source in the hypermetabolic patient (after injury). METHODS: Twenty-two patients were studied after multiple trauma and randomly assigned to either glucose or glycerol as the carbohydrate source (220 gm glycerol or 320 gm dextrose) during a lipid-based system of parenteral nutrition. In the immediate postoperative period, measurements were made of nitrogen balance, substrates, energy expenditure, insulin, glucagon, and liver function tests. RESULTS: In the glycerol group glucose concentrations in plasma were significantly lower, whereas glycerol levels increased nearly twentyfold. Insulin and glucagon levels increased in both groups; however, the rise in insulin level was greater in the glucose group, whereas glucagon increased in both groups to a similar degree. Nitrogen balance was restored to equilibrium in the glycerol group while remaining negative in the glucose group. No abnormalities in liver function test results or differences in serum albumin levels were noted in either group. A 12% thermic effect was noted in the glucose group but not in the glycerol group. CONCLUSIONS: Glycerol seems to be a viable fuel source in the traumatized patient, being associated with nitrogen retention and minimal thermal effect. A marked rise in plasma levels of glycerol does occur, but this does not appear to have any associated toxicity.

Adolescent

[Effect of omega-3-fatty acids on lipoprotein metabolism. Different effects in various phenotypes].

A review of the literature confirms a regular and significant lowering of serum triglycerides by omega-3 fatty acids. This effect is the more pronounced the higher the initial levels are. Accordingly, in type V hyperlipoproteinemia, it is particularly marked. In normolipemic subjects and in patients with hypercholesterolemia (type IIA), total cholesterol is only slightly reduced. In patients with elevation of cholesterol and triglycerides (types IIB, IV and V), both triglycerides and cholesterol are lowered. This decrease is mainly obtained by reduction in VLDL cholesterol. In the case of types IV and V, on the other hand, triglyceride reduction is associated with an elevation of LDL and HDL cholesterol. At present, it is not clear whether the increase in LDL cholesterol is of a transient nature and prognostically irrelevant. It can be prevented by reducing the intake of saturated fat. HDL cholesterol is decreased by high doses and increased by low doses of omega-3 fatty acids. In the differential treatment of hyperlipoproteinemias, consideration should be given to these points.

Fatty Acids, Omega-3

Stress and fatty liver--possible indications for dietary long-chain n-3 fatty acids.

The favourable effects of eicosapentaenoic acid (EPA)- and doco-sahexaenoic acid (DHA)-rich diets (marine fish, fish oil) on several risk factors for cardiovascular disease are well established. The present survey describes possible new indications for diets supplemented with long-chain n-3 fatty acids. During a standardized psychophysiological stress test (arithmetic, sentence completion tasks) systolic blood pressure after 2 weeks of diets supplemented with either 60 ml/day of sunflower or linseed oil was significantly decreased. During the sunflower oil-rich diet 45 g/day of linoleic acid (LA) and during the linseed oil-rich period 38 g/day of alpha-linolenic acid (LNA) were ingested. After a 2-week diet supplemented with mackerel (2 cans/day equivalent to 2.2 g/day of EPA and 2.8 g/day of DHA) systolic and diastolic blood pressure within the same test design appeared significantly lower. After a herring diet providing 2 cans/day, equivalent to 1.0 g of EPA and 1.8 g of DHA, the blood pressure-lowering effect was minor. The increase of thromboxane B2 (TxB2) during the stress test failed to occur after the fish diets. The results suggest a stress-protective effect of polyenoic acid-rich diets, which appears most pronounced and dose-related after long-chain n-3 fatty acids. In human liver an increase of fat droplet size in hepatocytes is associated with a decrease of the percentage of EPA in liver triglycerides. A diminution of plasma free fatty acids (FFA) after a mackerel diet might contribute to a depressed synthesis of liver triglycerides.(ABSTRACT TRUNCATED AT 250 WORDS)

Fatty Acids, Nonesterified

Glucose-induced or postprandial hyperinsulinemia in mild essential hypertension--an underestimated biochemical risk indicator?

Even if glucose tolerance is normal, a glucose-stimulated or postprandial hyperinsulinemia can frequently be observed in patients with early stages and mild forms of essential hypertension. Numerous epidemiological, clinical and experimental data suggest that hyperinsulinemia might be an independent risk factor for atherosclerosis which should be paid more attention. It could be hypothesized that, apart from the haemodynamic phenomenon of high blood pressure, the postprandial hyperinsulinemia of patients with mild essential hypertension might be relevant to their cardiovascular risk.

Arteriosclerosis

Different changes of n-6 fatty acids in lipoproteins from hyperlipemic subjects after diets supplemented with n-3 fatty acids.

After diets supplemented with canned mackerel or herring, in a cross-over design, containing different amounts of long-chain n-3 fatty acids (eicosapentaenoic acid, C20:5n-3-EPA, and docosahexaenoic acid, C22(6)n-3-DHA) an increase of both EPA and DHA was confirmed in triglycerides (TG), cholesterol esters (CE) and phospholipids (PL) of very low density (VLDL) and low density lipoproteins (LDL) as well as in high density lipoproteins (HDL) from hyperlipidemic subjects. An unexpected finding was the simultaneous increase of arachidonic acid (C20:4n-6-AA) in TG and CE and its constant portion in PL of lipoproteins, whereas linoleic acid (C18:2n-6-LA) appeared lower in CE and in PL of VLDL + LDL and HDL. In general, the changes were minor after a diet supplemented with canned herring providing a lower dose of n-3 fatty acids. The results indicate dose-related changes not only of n-3 fatty acids, but also of n-6 fatty acids in serum lipids after fish diets. This different behavior of LA and AA in serum lipids might be a new aspect in the interrelations and the dietary modulation of both families of polyunsaturated fatty acids (PUFA). The accumulation of AA in neutral lipids could be linked with an elevation of prostaglandin I2, which was found apart from an increased formation of prostaglandin I3 after diets supplemented with n-3 fatty acids. The concomitant increase of prostaglandins I2 and I3 spotlights widely ignored interrelations within the eicosanoid pathway, which become evident after diets enriched with long-chain n-3 fatty acids.

Adult