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Biomedical subjects

G Levin

Publications and source records attributed to G Levin.

At least 55 records · Page 3Linked to original sources
PubMed1988

Stress increases endogenous benzodiazepine receptor ligand-monoamine oxidase inhibitory activity (tribulin) in rat tissues.

The presence of both MAO and benzodiazepine (BZ) receptor binding inhibitory activities in rat tissues has been reported previously. The two activities were similarly and unevenly distributed in the tissues. This dual inhibitory activity has been termed tribulin. We report here the effect of 1 1/2 hrs cold restraint stress on tribulin activity in rat tissues together with biochemical evidence to support the concept of a physiological role of tribulin. Stress induced a significant increment of both activities in heart and kidney while no significant changes were observed in the other tissues studied. Hearts and kidneys from stressed rats also showed a significant decrease of MAO activity, a significant increase of dopamine content and a significant decrease of the binding of 3H-Ro 5-4864 to peripheral BZ receptors. Scatchard analysis of the saturation curves carried out using 3H-Ro 5-4864 (0.4-10 nM) showed significant Bmax decreases in both organs. No significant change in either of these inhibitory activities was observed in the other tissues studied. These data provide support for a role of tribulin in the biochemical response to stress.

Animals↗
PubMed1988

Total plasma dopamine/norepinephrine ratio in catecholamine-secreting tumors. Its relation to hypertension.

We used a radioenzymatic method to determine plasma levels of free and total (free plus sulfoconjugated) norepinephrine and dopamine in 20 children with neuroblastoma (two were hypertensive), seven patients with pheochromocytoma, and 39 normotensive controls (24 children and 15 adults). No significant differences were noted between the two control groups. Patients with neuroblastoma and pheochromocytoma showed significantly higher levels of free and total norepinephrine than controls (p less than 0.01), and those with pheochromocytoma had higher levels than those with neuroblastoma (p less than 0.01). Although the differences were not statistically significant, free dopamine was higher in both groups of patients than in controls. Total dopamine was significantly higher in patients than in controls (p less than 0.01). A positive correlation was noted between levels of total norepinephrine and total dopamine in controls (r = 0.41, p less than 0.05) and in patients with neuroblastoma (r = 0.72, p less than 0.001). Such a correlation was not found in patients with pheochromocytoma. The total dopamine/total norepinephrine ratio was higher (p less than 0.005) in patients with neuroblastoma than in controls and patients with pheochromocytoma. Patients with pheochromocytoma had significantly lower ratios than the other groups (p less than 0.001). A negative correlation was found between the ratios in the different groups and either systolic (p less than 0.001) or diastolic (p less than 0.001) blood pressure. Our results not only support a role for plasma dopamine in the regulation of blood pressure but also suggest that, regardless of the actual levels of both catecholamines, a balance has to be achieved in order to maintain normal blood pressure levels.

Adrenal Gland Neoplasms↗
PubMed1988

Incidence of otosclerosis.

On the basis of data obtained from different sources, the incidence of clinical otosclerosis in Sweden in the year 1981 was estimated to be 6.1 cases per 100,000 population. This figure is lower than others reported previously. The annual incidence of stapedectomies is 8.3 per 100,000 population.

Adolescent↗
PubMed1987

Effects of somatostatin on gallbladder emptying.

Because approximately 80% of reported patients with somatostatinomas have gallstones, this study was performed to determine the effects of exogenous somatostatin on gallbladder emptying responses to liquid and solid meals, direct cholinergic stimulation by bethanechol, indirect cholinergic stimulation by sham feeding, and intravenously administered octapeptide of cholecystokinin. Gallbladder emptying was quantitated using 99mTc-HIDA and a gamma-camera on line to a digital computer. Somatostatin, administered at a dosage of 7 micrograms/kg X h, prevented the gallbladder emptying responses to both test meals, sham feeding, and bethanechol. The maximal gallbladder emptying response to octapeptide of cholecystokinin at 5.0 ng/kg X min was reduced from 93.2% +/- 4.8% to 57.1% +/- 9.9% (p less than 0.01) and to octapeptide of cholecystokinin at 0.5 ng/kg X min from 91.3% +/- 5.3% to 14.8% +/- 4.2% (p less than 0.01). These findings suggest that somatostatin is a potent inhibitor of gallbladder emptying in humans. This may be an important factor in the development of gallstones in patients with somatostatinomas.

Adult↗
PubMed1986

Effect of bromocriptine on plasma catecholamines in normal subjects and prolactin-secreting tumor patients.

The effect of short term bromocriptine (5 mg/day, 5 days) on plasma epinephrine (E), norepinephrine (NE), dopamine (DA) and prolactin (PRL) was studied in 4 normal women and 6 bearing PRL-secreting tumors. When studied on placebo no significant differences were found between controls and patients in E, NE and DA plasma levels. Bromocriptine induced: a 70% decrease in PRL levels in both groups, a significant (p less than 0.05) decrease in plasma NE levels in the control group, no significant change in plasma NE levels in the hyperprolactinemic patients when considered as a group. These results do not indicate that bromocriptine is a useful tool in the diagnosis of defective central dopaminergic regulation since individual responses of the PRL-secreting tumor patients were variable. Nevertheless, the impaired response of the group as a whole may be suggesting an underlying alteration of DA2 receptor activity in these tumor patients.

Adolescent↗
PubMed1986

Irreversible ototoxic effect of erythromycin.

Between 30 and 40 cases of reversible ototoxic side effects of erythromycin therapy have been reported previously but to our knowledge none with irreversible adverse reactions. A case of persistent tinnitus after intravenous erythromycin therapy is reported in the following.

Erythromycin↗
PubMed1984

Evaluating self-help support groups for medical students.

Self-help support groups for medical students represent one strategy for dealing with the emotional stresses of medical training and the diminished human sensitivity of students that often accompanies that experience. Support groups at the Albert Einstein College of Medicine were evaluated by 26 students who completed a nine-part questionnaire. The respondents indicated that they were primarily drawn to these groups because of a desire for social affiliation and an opportunity to express their feelings in a "safe" environment. Members shared in the leadership responsibilities of the group and dealt with external personal problems of the students rather than with the internal group dynamics. The gains derived from participation in these groups included opportunities for nonprofessional contact with faculty members, getting help and support from fellow students, and participation in stimulating discussions about the medical field. Students rated the groups as "meaningful" and expressed a desire for more frequent meetings.

Adult↗
PubMed1983

Evaluation of sympathetic nervous system and adrenomedullary activity in normal children.

In 22 healthy children heart rate, blood pressure and plasma levels of epinephrine (E) and norepinephrine (NE) were evaluated under basal conditions and in response to standing (5 min). Basal plasma E and NE levels found in these children were (means +/- S.E.M.) 139 +/- 17.9 pg/ml and 236 +/- 31.0 pg/ml respectively. Ten out of the 22 children reported dizziness and discomfort by the end of the 5 min standing period. These children showed not only a greater decrease in both systolic and diastolic blood pressure but also a lower basal heart rate, a tendency to higher basal NE levels and a blunted plasma NE response (23 +/- 7%) when compared with children not reporting symptoms (60 +/- 9%, P less than 0.01). Plasma E levels also showed an increment although a wide range of individual responses was observed in both groups.

Adrenal Medulla↗
PubMed1982

Catecholamines levels and parotid secretion in children with chronic atopic dermatitis.

The purpose of this study was to evaluate the in vivo state of both branches of the autonomic nervous system in children with chronic atopic dermatitis. In 15 patients, age 4 to 11, the following parameters were analyzed: (1) basal plasma levels of epinephrine, norepinephrine, and dopamine; (2) poststimulation (standing and i.v. furosemide administration); (3) basal urinary excretion of epinephrine, norepinephrine, and vainillin mandelic acid; (4) 30 min postfurosemide administration; (5) parotid secretory response to intraoral 0.1 m citric acid: flow rate, saliva pH, and concentrations of bicarbonate, chlorides, inorganic phosphates, total protein, and amylase activity. No differences in plasma and urinary basal levels of the catecholamines were observed. In response to standing, plasma norepinephrine from atopic children showed a greater increase than that seen in normal healthy children. From the salivary factors studied, no differences were found in parotid flow-rate, bicarbonates, chlorides, and inorganic phosphates. Protein concentration as well as amylase activity were significantly decreased in children with atopic dermatitis. These findings suggest that in atopic dermatitis, the beta-sympathetic mediated responses are impaired; on the other hand, parasympathetic mediated responses remain preserved.

Catecholamines↗
PubMed1978

Identifying and meeting clients' needs in six community mental health centers.

Using an intrument called SNAPOR--Services Needed, Available, Planned, Offered, and Rendered--the authors investigated the mental health service needs of 643 clients in six community mental health centers and the adequacy with which they were met. The centers' intake workers completed the first part of the instrument, immediately after the initial interview, to identify which of 13 services clients needed and to estimate the availability of the services. Follow-up eight weeks later indicated which of the needed services had been offered and which were actually given. Individual sessions and medication were the needs most often identified. The percentages of needed services that were ultimately provided ranged from lows of 3 to 10 per cent, for various kinds of rehabilitation, to a high of 84 per cent, for 24-hour hospitalization.

Community Mental Health Services↗
PubMed1977

Clinical applications of biofeedback: implications for psychiatry.

The authors briefly describe biofeedback techniques such as EMG feedback, temperature feedback, and heart rate feedback, along with reports from the literature about their application to specific problems such as subvocalization while reading, Raynaud's disease, cardiac arrhythmias, and epilepsy. Many clinical applications of biofeedback are aimed at inducing relaxation, a state that has important psychotherapeutic potential. The authors suggest that biofeedback could be used to reduce a patient's general level of arousal or as an adjunct to behavior therapy or insight therapy. While there have been no reports in the literature of any harmful effects secondary to feedback training, the authors caution that some patients may respond negatively to an objectively measured state of relaxation.

Anxiety↗