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Biomedical subjects

M Singer

Publications and source records attributed to M Singer.

At least 145 records · Page 8Linked to original sources
PubMed1988

Use of exercise Doppler for non-invasive haemodynamic optimization of dose and identification of poor responders to an oral anti-anginal agent. A double-blind dose-finding study of nisoldipine.

Nisoldipine, a new dihydropyridine calcium antagonist, was examined for its dose-related haemodynamic effects using exercise-induced changes in aortic blood flow as measured by Doppler ultrasound. Following a two-week placebo run-in, 24 patients with stable angina pectoris were assigned double-blind to one of three groups receiving doses ranging from 2.5-20 mg/day over 8 weeks, given once or twice daily. Doppler studies identified the low dose group as responding less well at the placebo phase compared to the other two groups. There was an overall improvement in percentage change of peak velocity and stroke distance with exercise at all doses, with a dose of 5 mg/day giving optimal benefit in both variables (P less than 0.05) and no additional benefit being seen on twice-daily dosage. Six patients reporting increased chest pain exhibited a significantly worse rise in peak velocity and a fall in stroke distance to exercise (P less than 0.05) whilst on active drug compared to those who responded favourably. Doppler ultrasound can be of benefit in the haemodynamic assessment of new drugs, the recognition of non-responders and the optimization of therapeutic regimes.

Administration, Oral↗
PubMed1988

Fantasy or structural defect? The borderline dilemma as viewed from analysis of an experience of nonhumanness.

The experience of nonhumanness, a crucial aspect of the phenomenal self of borderline states, is studied in two cases to test assumptions concerning the application of the classic ego-psychological or object-relations and self-psychological models. Are these experiences to be seen as fantasy and treated as manifest content, with dynamically active unconscious conflict and meaning, requiring interpretation, or as a developmental arrest in which structural disturbances are ameliorated through clarifying and empathic interventions? The first case is of a patient with a neurotic depression and hysterical and obsessional character traits, treated in a classic psychoanalysis. Even though dyadic oral and anal fantasies were strongly in evidence, the ego was well integrated. The second case is of a severe borderline patient who showed depressive panic and agoraphobia. Her major ego disturbances, poorly integrated and differentiated self- and object representations, and primitive defenses prevented effective psychoanalytically oriented treatment. Interventions were used to consolidate self-representations, internalize tension-regulating structures, promote adaptive ego functions and reality testing. These clarifications were necessary to move the patient to where she could tolerate facing unconscious dynamic conflicts. Only at that point could repression be lifted, memory emerge, and interpretation be utilized.

Adult↗
PubMed1987

The LINE-1 DNA sequences in four mammalian orders predict proteins that conserve homologies to retrovirus proteins.

Recent work suggests that one or more members of the highly repeated LINE-1 (L1) DNA family found in all mammals may encode one or more proteins. Here we report the sequence of a portion of an L1 cloned from the domestic cat (Felis catus). These data permit comparison of the L1 sequences in four mammalian orders (Carnivore, Lagomorph, Rodent and Primate) and the comparison supports the suggested coding potential. In two separate, noncontiguous regions in the carboxy terminal half of the proteins predicted from the DNA sequences, there are several strongly conserved segments. In one region, these share homology with known or suspected reverse transcriptases, as described by others in rodents and primates. In the second region, closer to the carboxy terminus, the strongly conserved segments are over 90% homologous among the four orders. One of the latter segments is cysteine rich and resembles the putative metal binding domains of nucleic acid binding proteins, including those of TFIIIA and retroviruses.

Amino Acid Sequence↗
PubMed1987

Thallium-201 myocardial scintigraphy in coronary triple-vessel disease: an attempt to increase sensitivity using quantitative methods.

In order to increase the sensitivity of thallium-201 exercise scintigraphy in patients with triple vessel coronary disease (TVD), we first examined retrospectively myocardial scintigrams of 179 patients with TVD, as documented subsequently by cardiac catheterization. Ischemia had been diagnosed visually in 141 (79%), scar without ischemia in 25 (14%) and no apparent perfusion defect in 13 (7%) cases. The subset of TVD patients without scintigraphic ischemia (i.e. those with scar or no perfusion defect) was then compared to a control group with normal coronary angiography using four quantitative criteria: (1) in preset-count analog images, a quotient of the exposure times rest image/stress image; (2) in preset-time digital images, a quotient of counts/pixel in stress image/rest image using two different myocardial regions of interest (ROI); (3) a similar quotient using paracardial lung ROIs of three different sizes; (4) the absolute values of stress lung uptake. Quotients (1) and (2) were expected to be lower in TVD patients than in normal controls due to exercise-induced global ischemia, quotient (3) and value (4) were expected to be higher due to exercise-induced left ventricular dysfunction with increased lung uptake of thallium-201. All results showed a tendency to confirm these hypotheses; significant differences (P less than 0.05) between patients and controls were obtained in all lung quotients and in 3 of 12 myocardial quotients. No significant differences were observed in the exposure time quotients of preset-count images and in the stress lung uptake. Due to overlapping values, it was not possible to fix normal and pathological ranges of any quotient.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗
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↗