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Biomedical subjects

W Nelson

Publications and source records attributed to W Nelson.

At least 55 records · Page 3Linked to original sources

Relative costs of specialist services in a family practice population.

The frequency and cost of referrals to specialists in March 1984 for 8980 rostered patients attending a family practice clinic located in a teaching hospital were analysed. The patients made 1891 visits to specialists. In all age groups and for all specialties female patients were more likely to be seen. The total direct provider costs were higher for female patients than for male patients. However, costs per patient seen were higher for male patients, except for psychiatry and medicine. Visits to surgeons had the highest total cost, while visits to psychiatrists had the highest cost per patient seen. Of the direct provider costs 61% was for specialist services. The family physician, in the "gatekeeper" role, has an opportunity to control some of the costs of the health care system by ensuring that the best and most efficient use is made of the referral network.

Adult↗

Demyelinating encephalopathy in Lyme disease.

A 38-year-old man from southeastern Connecticut developed a diffuse encephalopathy with partial complex seizures, followed weeks later by arthritis, cryoglobulinemia, and increased serum IgM. CT showed confluent low-density lesions in the deep cerebral white matter consistent with demyelination. Neither the encephalopathy nor the CT abnormalities improved. Lyme disease was diagnosed serologically 4 years later.

Adult↗

Is there a tardive dysmentia?

A change in the phenomenology of schizophrenia has been observed over the past several decades; affective disturbances and phasic courses have become more evident. Although there is no obvious single explanation for these changes, several ideas have been considered. The advent and use of antipsychotic drugs over the past 30 years stands out as the most significant change. Because it is well known that chronic treatment with antipsychotic drugs can induce tardive dyskinesia and has been hypothesized to induce a supersensitivity psychosis, it is reasonable to believe that other behavioral changes may occur over time. We here describe a behavioral disorder that we have termed tardive dysmentia, involving changes in affect, activation level, and interpersonal interaction. A relationship between tardive dysmentia and tardive dyskinesia is suggested. It is our hypothesis that tardive dysmentia contributes to the changing course of schizophrenia and occurs after long-term treatment with antipsychotic drugs.

Adult↗

Behavioral and physiological effects of ethanol in high-risk and control children: a pilot study.

Blood and breath acetaldehyde levels were measured following ethanol ingestion (0.5 ml/kg) in 11 boys familially at risk for alcoholism and 11 age-matched controls. No significant differences were found between groups for acetaldehyde, objective, or subjective measures of intoxication. Previous reports of acetaldehyde as a marker of risk for alcoholism were not confirmed. Baseline behavioral state predicted response to alcohol. Children tended to have a subjective response in a direction opposite from the baseline mood state.

Acetaldehyde↗

Glycine and benzoate conjugation and glycine acyltransferase activity in the developing and adult rat: possible relationships to nonketotic hyperglycinemia.

We report investigations of benzoate and glycine metabolism and glycine acyltransferase activity in rats. These studies provide insights related to the therapy and pathophysiology of human nonketotic hyperglycinemia. Liver acyltransferase activity increased sharply postnatally from low levels at birth, but transferase activity was absent in the brain. The enzyme level was unchanged in either organ after administration of 2,3,7,8-tetrachlordibenzodioxin, phenobarbital, benzoate or a high glycine diet. Brain and liver glycine levels remained unaltered during acute or chronic benzoate-induced reductions in plasma glycine levels. Plasma and brain glycine contents were measured in rats at different ages following a single injection of 3 mg glycine/g body weight; after injection, glycine levels in the brain were comparable in severely symptomatic neonatal rats and older asymptomatic rats, suggesting a similar glycine influx but a selective susceptibility of the newborn brain to toxicity from acute hyperglycinemia. When a 3.4% glycine diet was ingested for up to 30 days ad libitum, levels of plasma glycine rose about 4- to 5-fold from those achieved on a diet containing one tenth as much glycine, but brain and liver glycine concentrations increased only 2-fold or less in the chronically hyperglycinemic animals.

Acyltransferases↗

Cryoanalgesia for post-thoracotomy pain.

Intercostal block by a freezing technique was compared with blockade by local anaesthetics or no blockade as a method of treating post-thoracotomy pain. The 15 patients who received cryotherapy had significantly less postoperative pain than the 9 patients whose nerves were blocked by local anaesthetics or who did not receive any nerve block. The interruption of nerve function produced by cryotherapy was temporary (not more than 30 days), and there were no adverse sequelae.

Analgesia↗

Rhythm-adjusted age effects in a concomitant study of twelve hormones in blood plasma of women.

The concentrations of luteinizing hormone, prolactin, estrone, estradiol, 17-hydroxyprogestrone, cortisol, aldosterone, dehydroepiandrosterone, thyrotropic hormone, triiodothyronine, thyroxin and insulin were determined in blood plasma obtained from women aged 15 to 59 years. Blood was sampled at intervals of 20 to 100 min throughout 24-hour spans in each of the four seasons and (in the case of cycling women) in four different stages of the menstrual cycle. With such sampling allowing for rhythmic and other fluctuations over a broad time scale it was possible to demonstrate statistically significant effects of age on hormones associated with the menstrual cycle (luteinizing hormone, prolactin, estrone, estradiol and 17-hydroxyprogesterone) and on dehydroepiandrosterone, but not on the remainder. The amplitude of circadian rhythms in several of the hormones also varied with age, thus affirming the value of sampling throughout this particular rhythm.

Adolescent↗

Chronotherapy of mammary cancer in rats.

Two studies were performed on female Fischer rats, housed 2/cage with food and water ad libitum in rooms maintained at 24 degrees C and with lights on daily for 8 hours (LD 8:16). In each study 192 rats were innoculated subcutaneously with 13762 mammary adenocarcinoma. Of these, 168 received chemotherapy, separate groups being treated at 1 of 6 different circadian stages. As controls, 24 tumour-bearing rats received saline while 24 rats without tumours received therapy. Chemotherapy consisted of 0.8 mg/kg Adriamycin (ADR) i.p. daily from day 11 to day 19 post tumour inoculation (except for days 16 and 17) followed by 1.6 mg/kg phenylalanine mustard (PAM) p.o. 3 times weekly beginning on day 20. In study-I PAM treatment was continued until 50% of the treated tumour-bearing rats died. In Study-II a 50% overall reduction in mean tumour size was not achieved before regrowth, presumably due to differences in the source of the rats, tumour-heterogeneity and/or other factors. At 50% overall tumour size reduction in the first study there was a statistically significant effect of treatment-timing on tumour size and on percent remission. The greatest reduction in mean tumour size and the highest percentage remission was observed in rats treated at the onset of darkness (activity), a timing similar to that observed in previous studies for optimal tolerance of ADR and PAM by the host. No deaths were observed in treated rats without tumours. When the drug combination used was sufficiently active against the tumour, the therapeutic index (selective toxicity) was improved by timing therapy according to circadian rhythms in the tumour-host system. This effect was achieved with doses not lethal to the nontumourous host. The presumption by others that chronotherapy depends on the use of toxic doses does not here apply.

Adenocarcinoma↗

Rhythmometry gauges treatment of mesor-hypertension in the seventh and eight decades of life.

Autorhythmometry of blood pressure by an individual over an age-span of 67 to 72 years showed a strong circadian rhythm superimposed upon significant circaseptan and circannual rhythms. Automatic BP monitoring with an Arteriosonde throughout 24-hour spans on 4 separate occasions, before and during treatment, also indicated a prominent circadian BP rhythm and a treatment-related reduction in circadian mesor. The concept of a blood pressure mesor reference for the antimesor-hypertensive treatment constitutes a valuable guideline in the control of "familial" mesor-hypertension.

Aged↗