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Biomedical subjects

M Singer

Publications and source records attributed to M Singer.

At least 73 records · Page 4Linked to original sources
PubMed1987

Open finger tip healing and replacement after distal amputation in rhesus monkey with comparison to limb regeneration in lower vertebrates.

The left thumbs and great toes of three 8 1/2 month old Rhesus monkeys (Macaca mulatta) were amputated in guillotine fashion one millimeter distal to the base of the nail and allowed to heal by the conservative open wound method. Healing occurred in seven to ten days in these small digits. Each of the thumbs and toes grew back with some blunting and shortening of the digit tips, but were functional. The new structures were cosmetically pleasing as in the human instances. The nails grew essentially to normal size and shape supported by the remaining portions of the distal phalanges. Histological studies showed no evidence of blastema formation such as is observed in the regenerating limb of the Urodele (newt) taken as the comparative representative. The possibility of improving the regrowth is discussed against the background of our knowledge of the importance of nerve during limb regeneration in lower vertebrates.

Amputation, Surgical↗
PubMed1987

Effects on physical performance of intrinsic sympathomimetic activity (ISA) during selective beta 1-blockade.

In 15 healthy, not specifically trained volunteers (age: 26.6 +/- 2.7 years) single equipotent doses of a selective beta 1-blocker with intrinsic sympathomimetic activity (ISA) (200 mg Epanolol-Visacor; V) and of a selective beta 1-blocker without ISA (100 mg Metoprolol; M) were compared with placebo (P) with respect to their influence upon physical performance capacity and metabolism in a random, double blind, cross-over experimental setting. The subjects underwent three step by step incremental treadmill tests and three treadmill endurance tests until volitional exhaustion. Maximum running speed and maximum oxygen uptake were used as measures of maximum performance capacity. Running speed and oxygen uptake related to individual anaerobic threshold, and running time and running distance in the endurance tests were used as measures of endurance capacity. Both maximum and endurance performances were reduced significantly by beta-blockade. No relevant differences were discerned between V and M. The uniform reduction in exercise heart rate with both beta-blockers demonstrated the application of equipotent doses. At rest, heart rate was significantly higher under V than under M. Carbohydrate metabolism was unaffected, both beta-blockers showing equal inhibition of lipolysis during exercise. We conclude that intrinsic sympathomimetic activity has no influence upon physical performance and metabolism during selective beta 1-blockade.

Adrenergic beta-Antagonists↗
PubMed1987

Intraoperative radiation therapy for advanced or recurrent head and neck cancer.

Between 1982 and 1984, we treated 28 patients with advanced head and neck cancer with surgery, combined with intraoperative radiation. All patients had squamous cell carcinoma. One patient had two separate sites treated and a second patient was treated on two occasions, allowing 30 sites for analysis. The overall survival for all patients treated was 67% at 1 year. Local failure occurred in 13% of those with close surgical margins and 25% of those with microscopic residual disease. With gross residual disease 100% had local failure. Patients with gross residual disease had significantly higher local failure than microscopic residual disease (p less than 0.02) or close surgical margins (p less than 0.01). Carotid blowout was the major treatment complication. We believe intraoperative radiation is an effective treatment for advanced or recurrent head and neck cancer when all gross disease has been resected.

Carcinoma, Squamous Cell↗
PubMed1986

Toward a political-economy of alcoholism: the missing link in the anthropology of drinking.

This paper addresses a shortcoming in the existing anthropological and related social science literature on alcohol use and abuse, namely the general inattention to global political-economic forces that have in the past and continue to reshape social relations and drinking practices cross-culturally. Following a critical review of the dominant approaches adopted in the varying explanations of heavy drinking and alcoholism, several alternative concepts are presented and developed in order to lay the ground for the emergence of a political-economy of alcoholism. The paper urges transcendence of the existing narrow boundaries of inquiry and perspective characteristic of most anthropological study of drinking and drinking problems.

Alcohol Drinking↗
PubMed1986

A double-blind comparative trial of zimelidine, amitriptyline, and placebo in patients with mixed anxiety and depression.

We performed a randomized, double-blind clinical trial comparing the efficacy and safety of zimelidine with amitriptyline and placebo in outpatients with major depression, in particular patients with mixed anxiety/depressive symptomatology. Overall, amitriptyline was more effective than zimelidine and placebo after 4 weeks of treatment. However, when those patients with more severe depression were specifically examined, both antidepressants were equal in efficacy and superior to placebo. We also found no evidence for a greater likelihood of a zimelidine-induced peripheral neuropathy in this study. The present results suggest that zimelidine may be more effective in the treatment of severely depressed patients, rather than those with more mild mixed anxiety/depressive syndromes.

Adult↗
PubMed1986

Effects of forelimb amputation and denervation on protein synthesis in spinal cord ganglia of the newt.

Analysis of the effects of forelimb amputation and denervation on [35S]methionine incorporation into the protein of newt brachial plexus nerve ganglia showed that amputation increases the level of protein synthesis about 4-fold as compared with that of control (nonamputated) animals. Denervation without amputation nearly doubles the level of protein synthesis as compared with controls. Analysis of labeled protein by means of two-dimensional gel electrophoresis and radioautogram revealed incorporation patterns that are similar to controls; this observation suggests that amputation affects nerve cells quantitatively rather than qualitatively, in influencing the production of putative neurotrophic agents. A group of basic proteins ranging in Mr from 15,000 to 31,000 are prominently expressed in these radioautograms from experimental ganglia and may be important in promoting forelimb regeneration in the newt.

Amputation, Surgical↗
PubMed1986

Expression and function of neural cell adhesion molecule during limb regeneration.

The neural cell adhesion molecule (NCAM) has been detected in regenerating limb bud of adult newts in addition to brain and peripheral nerves. In the regenerating tissue, NCAM was found primarily on mesenchymal cells and also in wound epidermis. Infusion of Fab fragments of antibodies to NCAM into limb buds at the early blastema stage delayed the regenerative process. Previous studies have indicated that NCAM serves as a homophilic ligand for adhesion among cells that express this molecule and, in doing so, can influence the interaction of nerves with their environment. The expression of NCAM in regenerating limb and the effects of antibody infusion are therefore consistent with the observation that limb regeneration requires interactions among axons and mesenchymal cells.

Animals↗
PubMed1986

The identification of adolescent substance abuse by health care professionals.

The purpose of the present study was to investigate the frequency with which health care professionals identify alcohol and drug problems in an adolescent clinic population. The results indicated that the health care professionals were apt to judge far fewer adolescents as having an alcohol/drug problem than as having other problems common to this age group. Furthermore, adjusted citywide prevalence rates of adolescent alcohol abuse (12.7%) exceeded health care professionals' judgments (3.0%) by over fourfold.

Adolescent↗
PubMed1986

Twice-daily nicardipine in the treatment of essential hypertension.

The antihypertensive effect of twice-daily nicardipine, an investigational calcium-channel blocker, was evaluated in a placebo-controlled, single-blind trial in 18 adult patients with essential hypertension (supine diastolic blood pressure [BP] of greater than or equal to 95 and less than or equal to 120 mmHg). Following a 4-week run-in period in which patients received placebo for the final 2 weeks, nicardipine was administered for 12 weeks with a treatment goal of a supine diastolic BP of less than 90 mmHg at 12 hours postdosing or to a maximum dose of 60 mg twice daily. Supine and standing BPs and heart rates were determined at 1 hour and 12 hours postdosing. At all dose levels, supine and standing BPs were reduced at 1 hour after dosing, with partial loss of efficacy seen at 12 hours. Increases in heart rate seen at 1 hour were not significant at 12 hours. Eight patients withdrew from the study for minor, although troublesome, side effects, such as palpitations and headaches. These data suggest that nicardipine monotherapy given in a twice-daily dosing regimen has only a limited role to play in the chronic treatment of patients with essential hypertension.

Adult↗
PubMed1986

Unemployment and its impact on adolescent work values.

This study examines the impact of unemployment on the work values orientation of adolescents. Using Super's (1970) Work Values Inventory, data were collected from 187 youths residing in a large midwestern city in the United States. Youths from families where the head of household had been unemployed for more than one year prior to the time of the study were compared to youths from a working-family environment. The findings of this study show little difference between work values orientation of youths from unemployed and employed families. The only variable which did prove to be significantly different settings appear to is "esthetics" (p less than .05), i.e., youths from unemployed settings appear to value new experiences and outlets for their abilities more than do youths of the comparison group.

Achievement↗
PubMed1985

Necessity of an adequate nerve supply for regeneration of the amputated pectoral fin in the teleost Fundulus.

The present work deals with determination of the threshold of nerve fibers per unit of amputation surface necessary for regeneration of the pectoral fins of a teleost, Fundulus. Partial denervation of the amputated pectoral fins, i.e., resection of one or two of the three nerves of the brachial (=pectoral) plexus revealed that the presence of a single one allows the amputated fin to regenerate. From these data and others obtained previously, it is concluded that the nervous requirements for a teleost fin to regenerate are similar or slightly lower than those for tetrapods, for example in the newt, which are capable of appendage regeneration.

Animals↗