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Biomedical subjects

Y Cohen

Publications and source records attributed to Y Cohen.

At least 217 records · Page 12Linked to original sources

Liposarcoma of the perineum and scrotum.

A case of liposarcoma of the perineum and scrotum, which presented as a huge haematoma and was left in place for three years prior to excision, is presented. The patient was treated by wide excision of the tumour, orchiopexy to the inguinal region and radiotherapy. To date, 30 months following surgery, the patient is completely asymptomatic and no tumour recurrence is evident either on physical and rectal examinations or on chest X-rays, ultrasonography and abdominal and pelvic computerized tomography.

Combined Modality Therapy↗

Update of experience in the treatment of localized carcinoma of the prostate by definitive external irradiation.

In 1987 a retrospective analysis was performed of 116 patients with carcinoma of the prostate localized to the pelvis who were treated by radiotherapy at the Northern Israel Oncology Center during the period between 1977 and 1982. It was shown that definitive external beam irradiation is an effective, simple, and easy treatment modality for localized prostatic cancer.

Actuarial Analysis↗

The value of postoperative irradiation in renal cell cancer.

This is a retrospective analysis of 147 evaluable patients, with histologically proven renal cell carcinoma, who were referred to our center between 1977 through 1988. All patients with disease limited to the kidney underwent nephrectomy. Post-operative megavoltage irradiation, with a median dose of 46 Gy, was given to 56 patients, using parallel opposing portals, or multiple field technique. Five and 10 year actuarial survivals in irradiated patients (Rt+) were 50 and 44%, respectively, and in non-irradiated patients (Rt-) 40 and 32%, respectively. The disease recurred locally in a total of 19 patients; 16 had tumor bed recurrence and three had scar recurrence. Local recurrence by stage was as follows: T2 N0M0: RT+ 0/17, RT- 2/28; T3 N0M0: RT+ 4/37 (10%), RT- 11/30 (37%) (p less than 0.05); T4 N0M0: RT+ 1/2, RT- 1/5. Two of the local recurrences in irradiated patients developed in a surgical scar which was not included in the treatment volume. Significant toxicity developed in three patients (5%). It is concluded that post-operative irradiation can reduce local recurrence rate in T3 N0M0 renal cell carcinoma. It is recommended that the surgical scar should always be included in the treatment volume and irradiated to a full dose.

Actuarial Analysis↗

Uptake of 5-hydroxytryptamine in rat isolated atria.

1. The mode of 5-hydroxytryptamine (5-HT) uptake by the rat isolated atria was studied and compared to noradrenaline (NA) uptake. 2. Rat isolated atria were incubated with 14C-5-HT (46 microM) or 3H-NA 0.4 microM). After washing, the radioactivity fixed in atria was counted and the total NA, 5-HT and 5-hydroxyindol-3-acetic acid (5-HIAA) atria contents were measured by HPLC. 3. 14C-5-HT uptake was reduced in atria from 6-hydroxydopamine (100 mg/kg, i.p., 48 hr before experiments) or reserpine (2.5 mg/kg, i.p., 24 and 48 hr before experiments) pretreated rats. 4. The incubation of atria with 5-HT (50 microM) at the same time as 3H-NA reduced the 3H-NA value fixed. 5. Addition of desipramine (1 microM) or hydrocortisone (150 microM) before the incubation of atria with 14C-5-HT was without any effect on 14C-5-HT uptake. In contrast, fluvoxamine (1 microM) or indalpine (5 microM) caused a slight inhibition. 6. These data indicate that 5-HT is taken into the NA storage vesicles within the atria sympathetic nerves. This uptake does not use the NA carrier and involves partly the 5-HT carrier. An extraneuronal accumulation was noticed and a part of it is intracellular.

Animals↗

Modulation of noradrenergic transmission in the rat isolated portal vein: role of prejunctional alpha 2-adrenoceptors and beta-adrenoceptors.

1. The effect of several adrenoceptor agonists and antagonists on the spontaneous and stimulus-evoked release of [3H]noradrenaline was studied in rat isolated portal vein. 2. Yohimbine (10(-6)M) increased the stimulus-evoked [3H]noradrenaline efflux. Adrenaline alone (3 x 10(-6)M) was without effect, while it increased the resting efflux when added together with yohimbine. 3. Propranolol alone was without effect on the release of [3H]noradrenaline. When added (2 x 10(-6)M) at the same time as yohimbine, it reduced the stimulation-induced 3H efflux. When added before adrenaline and yohimbine, propranolol (10(-5)M) reduced both spontaneous and stimulus-evoked release of [3H]noradrenaline. 4. The effect of several beta-blocking drugs was measured on the enhancing effect of yohimbine on the stimulation-evoked 3H efflux. The beta 1-adrenoceptor blocking drugs: atenolol (5 x 10(-6) and 10(-5) M), metoprolol (5 x 10(-6) and 10(-5) M), like the more selective bisoprolol (2 x 10(-6) and 4 x 10(-6) M) inhibited yohimbine activity. Likewise, propranolol (2 x 10(-6) and 5 x 10(-6)M) and the beta 2-adrenoceptor blocker ICI 118551 exhibited an antagonistic effect. 5. These results indicate the possibility for noradrenaline to activate presynaptic beta-adrenoceptors in rat portal vein. They show an interaction between the presynpatic alpha 2- and beta-adrenoceptor mediated systems in the release of noradrenaline. They suggest the presence and the activity of facilitatory beta 1-adrenoceptors.

Adrenergic beta-Antagonists↗

Striatal dopamine metabolism is differentially affected by insulin according to the genotype in Zucker rats: a microdialysis study.

The genetically obese Zucker rat presents several abnormalities related to insulin and brain monoamines, which may play a role in its impaired regulation of food intake and body weight. In a previous study, the possible insulin-monoamine interplay was investigated by measuring brain monoamine and metabolite levels in the three genotypes of the Zucker strain. In addition to the expected results, insulin had a particular effect on striatal dopamine (DA) release, regardless of ponderal status and genotype. We further investigated this point in the present study, using the brain microdialysis technique in the striatum. Lean homozygous Fa-Fa rats responded as expected to insulin with regard to striatal DA release, with increases in DA and 3-methoxy-tyramine levels and decreases in dihydroxyphenylacetic acid and homovanillic acid. Lean heterozygous Fa-fa rats showed a very specific response profile, with decreases in all dopaminergic parameters, suggestive of an effect on DA synthesis rather than DA release. This further emphasizes the marked differences between homozygous and heterozygous lean rats. The obese fa-fa rats clearly fell into two populations. The first showed a profile of response to insulin similar to that of the lean Fa-fa rats, in keeping with the disturbances related to the "fa" gene. The second showed an increase in all the dopaminergic parameters. This pattern of response was, however, different from that of the Fa-Fa rats. These opposing responses in the two obese populations did not reflect differences in the blood glucose response to insulin. One explanation is that 16 wk may be a critical transition period in the development of genetic obesity, with regard to brain monoamine disturbances and the response to insulin.

3,4-Dihydroxyphenylacetic Acid↗

Patterns of secretion of human chorionic gonadotrophin by superfused placental explants and the embryo--placental relationship following maternal use of medications.

There is great concern regarding maternal exposure to medications, especially in the first trimester of pregnancy because of the possible teratogenic effects. In the present study we have examined the consequences of maternal drug exposure in vivo upon placental secretion patterns of human chorionic gonadotrophin (HCG) and the relationship between the embryo and placenta in vitro. This was examined in samples obtained from various drug-exposed women following elective pregnancy termination at 8-9 weeks. The patterns of HCG secretion in superfused placental explants were different from those seen in control explants (without use of any medication). This was shown by changes in the pulse pattern and pulse frequency. In addition, the exposure of placental explants to various embryonic tissues modified HCG secretion in static cultures. In superfusion, co-perfusion with embryonic spinal cord tissue increased HCG secretion as opposed to that seen in similar incubations made with embryonic spinal cord tissue obtained from healthy women. Thus, our data suggest that maternal drug exposure alters both spontaneous hormone secretion by the placenta and the recently described embryo--placental relationship in vitro.

Chorionic Gonadotropin↗

Activities of WIN-57273, minocycline, clarithromycin, and 14-hydroxy-clarithromycin against Mycobacterium avium complex in human macrophages.

The activities of the fluoroquinolone WIN-57273, 14-OH clarithromycin (a human metabolite of clarithromycin), and minocycline against two virulent strains of Mycobacterium avium complex were evaluated in a model of intracellular infection and compared with that of clarithromycin. Human monocyte-derived macrophages were infected at day 6 of culture. Intracellular CFU at 60 min and intracellular and supernatant CFU on days 4 and 7 were counted after inoculation. The concentrations used, which were equal to peak levels in serum, were 3 micrograms of WIN-57273 per ml (MICs for the two strains, 1 microgram/ml), 4 microgram of 14-OH clarithromycin per ml (MICs, 8 and 2 micrograms/ml, respectively, at pH 7.4), 4 micrograms of minocycline per ml (MICs, 64 and 32 micrograms/ml, respectively), and 4 micrograms of clarithromycin per ml (MICs, 2 and 0.5 micrograms/ml, respectively, at pH 7.4). On day 7, compared with controls, WIN-57273, minocycline (P less than 0.02), clarithromycin, or different combinations of clarithromycin and the other drugs (P less than 0.001) slowed the intracellular replication of strain MO-1. 14-OH clarithromycin (P less than 0.02), clarithromycin (P less than 0.02), 14-OH clarithromycin plus clarithromycin (P less than 0.01), clarithromycin plus minocycline, or clarithromycin plus minocycline plus 14-OH clarithromycin (P less than 0.001) slowed the intracellular replication of strain LV-2. WIN-57273 was less effective than clarithromycin against strain MO-1 (P less than 0.05). Clarithromycin plus 14-OH clarithromycin plus minocycline (P less than 0.02) was more effective than clarithromycin alone against strain LV-2. Thus, clarithromycin plus minocycline, which corresponds in humans to three active molecules, may exhibit a better efficacy than clarithromycin in this model.

Anti-Infective Agents↗

Sparfloxacin, ethambutol, and cortisol receptor inhibitor RU-40 555 treatment for disseminated Mycobacterium avium complex infection of normal C57BL/6 mice.

Sparfloxacin (50 mg/kg of body weight given subcutaneously each day), alone or in combination with ethambutol (50 mg/kg given subcutaneously each day), was examined for its therapeutic efficacy against experimental infection induced with the Mycobacterium avium complex in normal C57BL/6 mice. In addition, the potential anti-infective role of RU-40 555 (100 mg/kg given intraperitoneally each day), a drug that inhibits the cortisol receptors, was examined in the same model. Treatments were started 24 h after intravenous bacterial challenge and were continued for 21 days. Compared with controls, sparfloxacin or ethambutol decreased the CFU counts in spleens and lungs (P < 0.001). The sparfloxacin plus ethambutol combination was more effective than sparfloxacin alone in spleens (P < 0.001) but not in lungs. The sparfloxacin plus ethambutol plus RU-40 555 combination was more effective than the sparfloxacin plus ethambutol combination in spleens and lungs (P < 0.001). Thus, in this model, RU-40 555 enhanced the antibacterial activities of the antibiotics tested. Results of the study showed that normal C57BL/6 mice infected with the M. avium complex can be used for the evaluation of antimicrobial agents.

Animals↗

Diurnal Cycles of Sulfate Reduction under Oxic Conditions in Cyanobacterial Mats.

Diurnal cycles of sulfate reduction were examined in a well-developed cyanobacterial mat which grew in an outdoor experimental hypersaline pond system at a constant salinity of 75 +/- 5% for 3 years. Vertical profiles of sulfate reduction were determined for the upper 12 mm of the microbial mat. Sulfate reduction activities were compared with diurnal variations of oxygen and sulfide concentrations measured by microelectrodes. Significant activity of sulfate-reducing bacteria was detected under aerobic conditions during the daytime, with maximal activity at 2 p.m. When comparing sulfate reduction activities in sediment cores taken at 6 a.m. and 12 a.m. and incubated at a constant temperature in the light and in the dark, a distinct stimulation of the activity in the vertical profile of sulfate reduction by light was evident. It is therefore concluded that the maximal in situ activities, measured at 2 p.m. in the chemocline of the cyanobacterial mat, cannot be attributed to diurnal changes of temperature alone. The response of sulfate-reducing bacteria to the addition of specific carbon sources was significantly different in the cyanobacterial layer, the anoxygenic phototrophic bacterial layer, and the permanently reduced layer of the microbial mat. Sulfate reduction in the mat layer exposed to high oxygen concentrations as a result of cyanobacterial oxygenic photosynthesis was enhanced only by glycolate; in the microzone where the chemocline is found during the daytime, ethanol was the only carbon source to enhance sulfate reduction, while both ethanol and lactate enhanced this activity in the permanently reduced zone.

Journal Article↗

Autoantibodies in the sera of patients with lymphoma.

Sera of 84 patients with Hodgkin's disease (HD) and 55 patients with non-Hodgkin's lymphoma (NHL) were examined for the presence of autoantibodies to ssDNA, dsDNA, Poly (I), Poly (G), cardiolipin, histones, RNP. Sm, Ro (SS/A), La (SS/B) and the common anti-DNA idiotype (16/6) using an enzyme-linked immunosorbent assay (ELISA). Anti-ssDNA antibodies were detected in the sera of 20 patients with lymphoma (23.8%), more among those with NHL than HD (16 vs. 4 patients p < 0.01). Anti-RNP and anti-Sm antibodies were found in 16 (21.7%) and 14 lymphoma patients (20%) respectively, significantly more than in the controls (p < 0.05) in both antibodies). These findings remained valid following subgrouping of the patients into those with HD and NHL. With all the other autoantibodies examined no significant difference could be observed in the incidence between lymphoma patients and controls. These results differ from our previous survey carried out on sera of patients with solid tumors in whom no increased frequency of any of the autoantibodies could be determined. In view of the evidence suggesting an increased risk of lymphoma in a number of autoimmune diseases our results extend this relationship to an increased incidence of autoantibodies among patients with lymphoma.

Antibody Specificity↗

Prevention of hospitalization by a community intensive mental health care unit.

The presented study sought to determine the ability of a psycho-social model of intensive care intervention to prevent hospitalization. One hundred and thirteen patients identified as "needing hospitalization" were followed from their first intervention until their exit from the unit, and were checked again, a year after discharge. The results of our follow-up show that within the one year follow-up, the percentage of patients who had been hospitalized among the unit's patients was lower than the percentage of hospitalization common in psychiatric hospitals. This conclusion applies to patients with previous hospitalizations, as well as for patients with no previous hospitalizations. The success of the Intensive Mental Health Care Unit in preventing hospitalization was importantly demonstrated among the group of schizophrenic patients who form the largest subgroup of psychiatric hospital patients. In this study, chances of improvement and of remaining out of the hospital for the follow-up period were higher among patients who were working than when they entered the unit. A cost estimate based on the results indicates that the model tested is also a very cost effective model for intervention.

Adult↗

Stage I-II low grade non-Hodgkin's lymphoma: prognostic factors and treatment results.

48 patients with stage I-II low-grade non-Hodgkin's lymphoma were treated by radiation and/or chemotherapy between 1970 and 1986. The histologic types were diffuse lymphocytic well differentiated, eleven patients; nodular lymphocytic poorly differentiated, 28 patients; nodular mixed, nine patients. Complete remission was obtained in 45 patients (94%). Overall survival was 83% and 68% at five and ten years, respectively. Five and ten-year relapse-free survival of complete responders was 71% and 57%, respectively. Univariate analysis of potential prognosticators showed the following to significantly increase the survival rate: one or two sites of disease (p less than 0.01), stage I (p less than 0.02), age less than 65 years (p less than 0.02), complete excision of tumor mass (p less than 0.03), and the use of radiotherapy (p less than 0.02). The extent of radiotherapy field did not affect survival. Multivariate analysis by the stepwise proportional hazards model of Cox showed that the use of radiotherapy was the factor which significantly produced better survival figures (p less than 0.03). It is concluded that two thirds of stage I-II low-grade lymphoma patients are potentially curable; radiotherapy plays a major role in the management.

Adult↗

Effects of chloral, chloralose and pentobarbitone on monoamine and (neuropeptide Y) NPY levels in various tissues in the rat.

Sampling of blood or tissues in experimental animals need frequently a general anesthesia. Some anesthetic agents are known to modify plasma levels of catecholamines; moreover NPY is co-released with noradrenaline or adrenaline under certain conditions. Thus, we investigated the effect of three general anesthetic agents, chloral, chloralose and pentobarbital (pentobarbitone) on the levels of monoamines and NPY in rat hypothalamus, medulla, atria and adrenals. Monoamines were analysed by high pressure liquid chromatography using an electrochemical detection and NPY was measured by radioimmunoassay (immunoradiometric assay, IRMA). Chloralose or pentobarbitone did not affect monoamine tissue levels. In contrast, chloral increased 5-hydroxyindolacetic acid and to a lesser extent serotonin levels in the hypothalamus. NPY tissue levels did not change whatever the anesthetic used. These results must be taken into account in pharmacological or toxicological studies which need the use of a general anesthesia.

Adrenal Glands↗

[Patient-controlled i.v. morphine for acute postoperative pain].

The use of patient-controlled i.v. analgesia for postoperative pain relief in 60 cases is described. 0.1% morphine was given by Bard or Graseby microprocessor. After a loading dose of 2-6 mg, the pump delivered a bolus of 0.8-1.5 mg of morphine every 8-12 min. The dosages necessary to provide good analgesia varied from 30-85 mg (mean 48). Good pain scores of 0-2 (on a scale of 5) were obtained in 92%. The method was also found satisfactory by the families and health care providers, and is highly recommended for control of postoperative pain.

Acute Disease↗

[Primary malignant lymphoma of the testis].

Among 715 patients with non-Hodgkin's lymphoma referred to this oncology center between 1973-1989, there were 7 (0.9%) with primary lymphoma of the testis. The mean age was 55 (range 23-78). The presenting symptom in all the 7 was testicular mass or swelling. 6 of them underwent inguinal orchiectomy and 1 had a testicular biopsy. The pathological subtype of the lymphoma in all 7 was the diffuse large cell type. The disease stage was IE in 3, IIE in 3 and IVE in 1. Only 1 had bilateral testicular involvement. 6 were treated primarily with various combinations of chemotherapy and 1 by radiotherapy. 3 developed recurrent disease (2 treated primarily with chemotherapy and 1 by radiotherapy) and died 14, 19 and 27 months, respectively, after diagnosis. 3 are alive with no evidence of recurrent lymphoma. Follow-up in an additional patient has been too short for evaluation. Primary testicular lymphoma is a relatively rare form of extranodal lymphoma. It has a tendency to early systemic progression and is potentially curable by aggressive combination chemotherapy.

Adult↗

Results of multimodal therapy in Ewing's sarcoma: a retrospective analysis of 20 patients.

A retrospective analysis was performed of 20 patients with Ewing's sarcoma treated by combined modality therapy, consisting of surgery, radiotherapy, and chemotherapy. Fourteen patients (70%) achieved complete remission and 5 patients (25%) were in partial remission at the end of treatment. One patient (5%) failed to respond to combined modality therapy. The overall 5 year actuarial survival was 64% and the disease free survival, 55%. Persistent or recurrent disease occurred in 8 patients (40%); one of them was salvaged by surgery and chemotherapy. Site and extent of primary lesion were prognosticators of patients' outcome. One patient developed radiation-related-sequelae. The efficacy of aggressive management consisting of wide surgery, radiotherapy and intermittent high dose chemotherapy is discussed.

Actuarial Analysis↗