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Biomedical subjects

L Cohen

Publications and source records attributed to L Cohen.

At least 433 records · Page 24Linked to original sources
PubMed1984

Response of sarcomas of bone and of soft tissue to neutron beam therapy.

A total of 51 patients were treated at Fermilab for sarcoma of bone (25 patients) and soft tissue (26 patients). Neutrons were delivered in twice weekly fractions over 6-7 weeks to total doses between 18 and 26 Gy. Long-term local control (greater than 2 years) was achieved in 24 patients (47%). Overall local control rates were 44% in the bone sarcomas and 50% in the soft tissue tumors. Chondrosarcoma appeared relatively more responsive with 9 out of 16 (56%) controlled, compared to osteogenic sarcoma with 2 out of 9 (22%) controlled. Among the soft tissue tumors, liposarcoma (5/7 controlled) and neurogenic sarcoma (3/3 controlled) appear to be more responsive than other tumors. The overall survival rate was 40% in the entire series. These results are comparable with international experience in neutron therapy of sarcomas of bone and soft tissues. Out of 263 soft tissue sarcomas treated with neutrons only to full dosage throughout the world, 152 (58%) were locally controlled. Similarly out of 74 sarcomas of bone so treated, 44 (60%) were controlled.

Bone Neoplasms↗
PubMed1984

Coping with abortion.

This study evaluated individual differences in coping style in response to an abortion procedure. The 55 subjects displayed a wide range of responses, although the average level of distress was fairly high. These women were quite similar to other stressed populations in their response to the Impact of Event Scale, providing evidence for a generalized stress response syndrome. When divided into groups based on coping style, "avoiders" were found to experience more distress that "nonavoiders," and "approachers" decreased in distress over time while "nonapproachers" did not. The implications of these findings are discussed in the context of the interaction between coping styles and counseling strategies.

Abortion, Induced↗
PubMed1984

The location of speech and writing functions in the frontal language area. Results of extraoperative cortical stimulation.

In three patients stimulation of the frontal speech area resulted in one or more of the following symptoms: speech arrest, writing arrest, or impaired rapid alternating movements of the tongue, fingers or toes. Speech arrest could be altered at individual points either with or without impairment of rapid movements or writing, but writing was not impaired without concomitant difficulties with either speech or rapid finger movements. Our data suggest that the frontal speech area may function to integrate complex motor functions, some speech related and others not. We also confirm previous conclusions that Exner's writing centre is not separate from Broca's area and that the writing defect in Broca's aphasia can occur without involvement of the motor strip.

Adult↗
PubMed1984

Prevalence of nontraditional dental hygiene practice.

There is little knowledge of the number or the work characteristics of dental hygienists outside the private-practice setting. This survey was conducted to determine the percentage of hygienists practicing in nontraditional (nonprivate-practice) settings and the types of settings in which they are employed. Mail questionnaires were returned from a total of 21,847 (56.9%) of the hygienists in the survey sample. The percentage of active hygienists practicing in nontraditional settings was 11.8. Dental or dental hygiene schools, and government and nongovernment-supported clinics were the most frequent nontraditional practice settings. State supervision requirements were found to be associated significantly with the prevalence of nontraditional hygiene practice.

Dental Facilities↗
PubMed1984

Single dose treatment of vaginal candidosis: comparison of clotrimazole and isoconazole.

The therapeutic efficacy of a single dose 500 mg tablet of clotrimazole was compared with two 300 mg tablets of isoconazole in an open randomised study of 100 patients with vaginal candidosis confirmed by mycological culture. One week after treatment 100% of the clotrimazole treated patients and 98% of the isoconazole treated group gave mycologically negative results. Five weeks after treatment these figures were 74% and 78% respectively, showing that both regimens were equally effective.

Adolescent↗
PubMed1984

Alcohol use patterns of graduate students in social work and in business.

This comparative study is among the first to survey the drinking behavior of graduate students in social service (N = 256) and in business (N = 147). A large majority (88%) drank. A significantly greater number of social service students abstained. Irrespective of school, age or religion, men and women drank at a similar level of frequency--several times weekly. Only business school women, controlling for age and religion, were significantly heavier drinkers than were women in social service. Older Hispanic social service men were significantly lighter drinkers than similar Caucasians. All women preferred wine, whereas men had no particular beverage preference. Although there was no significant difference in the location of drinking--in bars, restaurants or at home--most students drank in restaurants. Irrespective of previous course work or work experience with alcoholics, social service students wanted alcohol education. However, business students showed almost no interest in this area of study, despite the known deleterious role that alcohol misuse plays in the employment arena. Major conclusions are that both business and social service students lack alcohol education, although most drink. This is an important blind spot among business students, who will be making critical business decisions. It is also inadequate preparation for social service practice.

Adult↗
PubMed1984

Alcohol use among graduate business administration students.

This study of fully employed master's students in a graduate school of business administration found no significant differences in the drinking levels of men and women. The majority are heavy drinkers. There is a tendency for female and Jewish students to prefer wine. Despite the role that beverage alcohol plays in the corporate world, few students were interested in alcohol education.

Adult↗
PubMed1984

Vanadate effects on ocular pressure, (Na+, K+)ATPase and adenylate cyclase in rabbit eyes.

Topical administration of 50 microliter of 1% Na3VO4 caused a significant fall in intraocular pressure (IOP) in the rabbit eye at 90 min. Assay of ATPase of the iris and ciliary body in vitro at 90 min posttreatment showed no differences between control and treated (Na+, K+)ATPase, ouabain sensitive ATPase or vanadate sensitive ATPase. Accumulation of 48V-labelled orthovanadate in iris and ciliary body reached a plateau of 12 pmoles/mg dry tissue weight 4 hr after a single 25-microliter topical dose of 1% orthovanadate. In vitro inhibition of Na+ sensitive ATPase by sodium metavanadate had an IC50 of 1.8 mM, whereas a 1.8-fold stimulation of adenylate cyclase in iris-ciliary body (ICB) membranes in vitro occurred at 10 mM but not at 10 microM Na metavanadate. These results indicate that the vanadate content of the iris and ciliary body at the time of lowered intraocular pressure is too small to inhibit a significant fraction (greater than 10%) of (Na+, K+)ATPase, or cause a significant stimulation of adenylate cyclase, and that other cellular mechanisms are likely to be involved in the ocular hypotensive response to vanadate.

Adenylyl Cyclases↗
PubMed1984

Oxygen radical detoxification enzymes in doxorubicin-sensitive and -resistant P388 murine leukemia cells.

One of the proposed mechanisms for the cytotoxic effects of anthracycline compounds suggests that the effect is mediated through the formation of intracellular superoxide radicals. It is therefore possible that doxorubicin resistance is associated with increased intracellular enzyme capacity to convert these superoxide radicals to inactive metabolites. We have measured the relative activities of superoxide dismutase, glutathione peroxidase, and catalase in P388 mouse leukemia cells and in a doxorubicin-resistant subline. Since oxygen-reactive metabolites also play a role in mediating the cytotoxicity of ionizing radiation, the radiosensitivity of both cell lines was also studied. No significant differences in superoxide dismutase activity between these cell lines was observed, indicating that they have a similar capacity to convert superoxide anion radicals to hydrogen peroxide. P388 cells that are resistant to doxorubicin have 1.5 times the glutathione content and 1.5 times the activity of glutathione peroxidase measured in drug-sensitive P388 cells. However, incubation with 1-chloro-2,4-dinitrobenzene, which covalently binds glutathione, had no effect on the sensitivity of either cell line to doxorubicin. Measured catalase activity in drug-resistant P388 cells was one-third of the activity measured in doxorubicin-sensitive P388 cells. The activity of this enzyme was much higher than that of glutathione peroxidase in terms of H2O2 deactivation in both cell lines. It is therefore unlikely that doxorubicin-resistant P388 cells have an increased ability to detoxify reactive oxygen metabolites when compared to drug-sensitive cells. Doxorubicin-resistant P388 cells were significantly more sensitive to X-irradiation than were drug-sensitive P388 cells. These observations suggest that the difference in catalase activity in these cell lines may be associated with the observed differences in radiosensitivity.

Animals↗
PubMed1984

Reversible retinal vasospasm in magnesium-treated hypertension despite no significant change in blood pressure.

8 young, untreated, hypomagnesemic patients with a recent onset of high-renin essential hypertension, were treated with 750 mg Mg oxide daily. Only functional (vasospastic) lesions were observed in their retinal vessels. After 3 months of therapy, despite no significant change in blood pressure, complete reversal of the retinal changes was observed. The retinal vascular changes could be attributable to vasospasm secondary to hypomagnesemia since serum Mg levels normalized during treatment.

Humans↗
PubMed1984

Fast walking velocity in health and Duchenne muscular dystrophy: a statistical analysis.

Fast walking velocity was measured in 335 apparently healthy subjects, 180 males and 155 females, whose ages ranged from 3.5 to 24 years. These velocities increased with age and approached an asymptote of 3.44m/sec in males and 3.17 m/sec in females, a statistically significant difference (p less than 0.001). This parameter was also measured serially over periods of 18 to 132 months in 15 patients with Duchenne muscular dystrophy. A decrease in walking rate began between ages four and six. This decline was found to fit linear and monoexponential decay mode models equally. Average linear decay for all 15 patients was 0.0308 m/sec/month; and the average fractional decay was 0.0349/month. On average, by 10 years, the fast walking rate was reduced to about 29% of normal. This measure of disease progression followed a unique course in each subject, which could be mathematically characterized by a unique decay rate, and a unique walking velocity at age 10 years. Thus, in contrast to natural speed walking, the measurement of fast walking velocity has proved to be a simple and useful index for characterizing disease progression in Duchenne muscular dystrophy, and for evaluating therapeutic interventions.

Adolescent↗
PubMed1984

Clofibrate-induced muscular syndrome. Case report with ultrastructural findings and review of the literature.

A 70-year-old man with chronic renal failure was treated with clofibrate, 2.0 g daily for 6 days, and subsequently developed clofibrate-induced muscular syndrome (CMS), i.e., myalgia with severe muscle weakness and tenderness. Elevated muscular enzyme activities were found upon examination of his blood. Electron microscopic studies revealed atrophy of some muscle fibers and massive degenerative changes. The atrophic fibers were associated with damaged neuromuscular junctions. A literature survey of 44 cases with CMS is included.

Aged↗
PubMed1984

Serum magnesium in propranolol-treated patients with acute myocardial infarction.

A rise in free fatty acids (FFA) and a concomitant decrease in serum magnesium levels were found soon after acute myocardial infarction (AMI) in a group of 5 patients. Magnesium and FFA returned to normal levels within 3 days. No changes in serum FFA and magnesium levels were found in the postinfarction period in 5 patients who were under treatment with propranolol during the time they developed AMI. The linear model, magnesium = f(time, FFA), was investigated according to the stepwise regression-forward selection system. It was found that the magnesium level in AMI is best predicted by the FFA level (inverse correlation). In the period of 0-72 h after infarction, an inverse linear correlation was found to exist between the FFA level and the period of time after infarction.

Analysis of Variance↗
PubMed1984

Prolonged Q-Tc interval and decreased lymphocyte magnesium in congestive heart failure.

Lymphocyte Mg concentration was measured in 2 patients with congestive heart failure, on long-term diuretic treatment, and was found to be lower than normal. The patients exhibited prolonged Q-Tc intervals on ECG analysis. During treatment with Mg sulfate, the Q-Tc interval normalized as the lymphocyte Mg approached control values. An Mg-sparing diuretic was added to the therapeutic regimen.

Aged↗
PubMed1984

Magnesium sulfate in the treatment of variant angina.

41 episodes of anginal attacks were promptly terminated by a bolus of Mg sulfate administered intravenously in 15 patients with variant angina. Pretreatment with parenterally administered Mg sulfate in four of these patients prevented further attacks.

Aged↗
PubMed1984

Increased placental concentrations of 25-hydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 in pregnant rats treated with human chorionic gonadotropin.

Pregnant rats were injected intrajugularly with 2500 i.u. human chorionic gonadotropin (HCG) toward the end of gestation (days 18-19) and 7.0 pmoles of tritiated 25-hydroxyvitamin D3 [( 3H]25(OH)D3) the following day. They were sacrificed ten to 24 hours later. [3H]25(OH)D3 and the in vivo produced [3H]24,25-dihydroxyvitamin D3 [( 3H]24,25(OH)2D3) in lipid extracts from maternal serum, kidneys, placenta and fetal tissues were separated by Sephadex LH-20 chromatography, and high performance liquid chromatography (HPLC). HCG treatment of pregnant rats increased significantly 25(OH)D3 levels in the placenta and kidneys and 24,25(OH)2D3 level in the placenta. Fetal metabolites levels were unaffected by HCG treatment. Serum and kidney levels of 25(OH)D3 and 24,25(OH)2D3 in pregnant rats were significantly lower than in non-pregnant rats. Serum and kidney levels of both metabolites in non-pregnant female rats treated with HCG did not differ from the untreated controls. HCG may, therefore, be involved in regulation of fetoplacental vitamin D metabolism.

Animals↗