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Biomedical subjects

Y Cohen

Publications and source records attributed to Y Cohen.

At least 163 records · Page 9Linked to original sources
PubMed1995

Malignant germ cell tumors of the ovary: a study of 20 cases.

In a study of 20 patients diagnosed with malignant ovarian germ cell tumors between 1961 and 1993, clinical and pathologic findings were evaluated. Of the 20 patients, seven (35%) had dysgerminoma, two (10%) endodermal sinus tumor, three (15%) malignant teratoma, one (5%) malignant struma ovarii, one (5%) primary ovarian carcinoid, two (10%) benign teratoma with malignant transformation, and four (20%) combination germ cell tumor. Twelve patients (60%) had stage IA, five (25%) stage IC, and three (15%) stage IIIC. Twelve patients (60%) underwent conservative surgery and eight (40%) had at least bilateral salpingo-oophorectomy. At follow-up, 18 patients (90%) were alive free of disease, one (5%) had died of disease, and one (5%) had died of intercurrent disease. The actuarial 5-year survival rate was 93.3%. It is concluded that for young women who wish to preserve child-bearing capacity, regardless of the stage of the tumor, fertility-preserving surgery with complete surgical staging followed, if necessary by cisplatin-based combination chemotherapy is an appropriate and definitive treatment in the absence of involvement of the contralateral ovary and uterus. For patients in whom child-bearing capacity is not an issue, surgery should include total abdominal hysterectomy and bilateral salpingo-oophorectomy with complete staging, followed if necessary by chemotherapy.

Adolescent↗
PubMed1995

Aminoglycosides.

Despite their nephrotoxic and ototoxic side effects, AG remain useful antibiotics because of their major, rapid, and dose-dependent bactericidal effects. Combination therapy with an AG appears particularly important in neutropenic and other high-risk patients to provide broad-spectrum bactericidal activity, synergism, and reduction of emergence of resistant pathogens. OD AG therapy is associated with high peak levels in serum that maintain efficacy and low-to-undetectable trough levels in serum that attenuate the risk of toxicity. Administration of short-term OD AG therapy to patients not at risk without renal impairment may not absolutely require dosing monitoring. This therapeutic strategy has been proved useful in clinical trials, now including febrile episodes in neutropenic patients, but it should be avoided during infections in which antimicrobial synergism is required, such as enterococcal endocarditis.

Aminoglycosides↗
PubMed1995

Allogeneic human liposomal melanoma vaccine with or without IL-2 in metastatic melanoma patients: clinical and immunobiological effects.

The aim of this pilot study was to assess the clinical and immunological effects of human allogeneic liposomal melanoma vaccine alone or combined with Interleukin-2 (IL-2) in patients with metastatic melanoma. Four concurrent treatment arms were included: vaccine alone (A); vaccine combined with systemic IL-2 (B); vaccine combined with low-dose liposomal regional IL-2 (C); and low-dose regional IL-2 as in group C but without vaccine (D). Vaccine was prepared from semisynthetic phospholipids (dimyristol phosphatidylcholine and dimyristol phosphatidylglycerol) and membranes of six human melanoma cell lines. The latter were chosen as expressing MHC class I and II antigens and a "mosaic" of melanoma-associated antigens (MAAs) as detected by MoAbs R24, p97, CF21 and TA99. Nine of the 24 patients had objective clinical responses: of the ten patients treated with liposomal vaccine and low dose regional IL-2 (arm C), three had complete responses (CR) and three had partial responses (PR); of the five patients treated with liposomal, low-dose regional liposomal IL-2 only (arm D), three had PRs. No clinical responses were seen in patients treated by vaccine alone (A) nor in patients treated by vaccine and systemic IL-2 (B). Patients' in vivo and in vitro cellular immune responses were closely monitored. Conversion to positive cutaneous delayed type hypersensitivity (DTH) to membrane vaccine (without liposomes) was induced only in the six clinical responders of arm C. Positive DTH correlated with augmented in vitro proliferative lymphocyte responses stimulated by melanoma cell lines and membrane preparation and with the augmented cytolytic activity against melanoma cell lines.

Adult↗
PubMed1995

Use of normal C57BL/6 mice with established Mycobacterium avium infections as an alternative model for evaluation of antibiotic activity.

Several murine models have been used to evaluate the activities of antimicrobial agents against Mycobacterium avium infection. The main model used is the beige mouse model, but beige mice are expensive and not easily available. Thus, we developed a model of infection in wild C57BL/6 mice. The drugs that exhibited some activity in a previous model of early infection were evaluated in a new model of established infection. Sparfloxacin (50 mg/kg of body weight), ethambutol (50 mg/kg), minocycline (25 mg/kg), and the inhibitor of the cortisol receptors RU-40555 (100 mg/kg) were compared with clarithromycin (50 mg/kg). Treatments were started 5 weeks after the inoculation and were continued for 21 days. Sparfloxacin and RU-40555, which exhibited a moderate activity in the model of early infection, were not effective in this model of established infection. Clarithromycin and combinations with clarithromycin kept their activities against M. avium infection, both in the spleen and in lungs. The present model of established infection of normal C57BL/6 mice is more relevant than the model of early infection for a stringent evaluation of drugs.

Animals↗
PubMed1995

Activities of roxithromycin against Mycobacterium avium infections in human macrophages and C57BL/6 mice.

The activity of roxithromycin against three clinical isolates of Mycobacterium avium was compared with that of clarithromycin both in a model of infection of human monocyte-derived macrophages and in a model of established infection of C57BL/6 mice. In the cell culture model, roxithromycin and clarithromycin were bactericidal for strains MO-1 and N-92159 and bacteriostatic for strain N-93043. For the three strains, the differences between the intracellular activities of roxithromycin and clarithromycin were not singificant after 7 days of treatment. Mice were infected with the MO-1 strain. Drugs were given by gavage at a dosage of 200 mg/kg of body weight 6 days per week for 16 weeks starting 5 weeks after infection. At the end of treatment, clarithromycin was more effective than roxithromycin in lungs; roxithromycin was as effective as clarithromycin in spleens. Thus, the activity of roxithromycin was comparable to that of clarithromycin both in vitro and in vivo.

Animals↗
PubMed1995

Mechanical ventilation with heated humidifiers or heat and moisture exchangers: effects on patient colonization and incidence of nosocomial pneumonia.

The contribution of ventilator circuit bacterial contamination to the occurrence of ventilator-associated pneumonia remains controversial. In a previous study, we found that the incidence of pneumonia was identical with ventilator circuit changes every 48 h and with no ventilator circuit changes. The present study prospectively assessed whether keeping ventilator circuits clean with a heat and moisture exchanger exhibiting antimicrobial barrier properties affects patient colonization and the incidence of nosocomial pneumonia in patients receiving mechanical ventilation for more than 48 h. Consecutive patients were randomly allocated to humidification with either a heat and moisture exchanger (Group 1, n = 61) or a heated humidifier (Group 2, n = 70). In both groups, no circuit changes were performed throughout ventilatory support. Duration of mechanical ventilation was identical in both groups (10 +/- 8.6 d (range: 2 to 47) in Group 1 and 12.5 +/- 14.2 d [range: 2 to 85] in Group 2). The incidence of pneumonia (positive quantitative culture of protected brush specimen) was similar in both groups (6/61 and 8/70 in Groups 1 and 2, respectively; p = 0.8), as was duration of ventilation prior to pneumonia (9 +/- 5.9 versus 8.2 +/- 5.7 d; p = 0.8). Ventilator tubing contamination was considerably reduced with the use of a heat and moisture exchanger. In contrast, bacterial colonization of the pharynx and trachea was identical in both groups. These results suggest that circuit colonization plays little or no role in the occurrence of ventilator-associated pneumonia, provided usual maintenance precautions are applied.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Dose intensity of cisplatin-based chemotherapy in epithelial ovarian carcinoma. An important factor affecting survival.

Forty-three patients with epithelial ovarian carcinoma, were treated by cyclophosphamide and cisplatin (CP) following initial laparotomy. The mean dose intensity (DI) and mean relative dose intensity (RDI) respectively were for cyclophosphamide: 166.69 mg/sqm/week and 0.67, and for cisplatin: 16.29 mg/sqm/week and 0.65. The mean average relative dose intensity (ARDI) was 0.66. The three-year survival for all patients was 44.3%. The three-year survival for patients receiving cyclophosphamide with a RDI of more than median value was 63.82%, while for patients receiving cyclophosphamide with a RDI of less than median value three-year survival was 26.3% (p < 0.02). The three-year survival for patients receiving cisplatin with an RDI of more than median value was 62.01%, as compared to 24.17% for patients receiving cisplatin with a RDI of less than median value (p < 0.02). The three-year survival for patients receiving the CP regimen with an ARDI of more than median value was significantly higher than that for patients receiving the CP regimen with an ARDI of less than median value (63.82% versus 26.03%, p < 0.02). Dose intensity of cisplatin-based chemotherapy in epithelial ovarian carcinoma is an important factor affecting survival.

Adult↗
PubMed1995

Epidemiological aspects of enterotoxigenic Escherichia coli diarrhoea in infants in the Jerusalem area.

BACKGROUND: As most of the clinical laboratories in Israel do not use toxigenicity testing as a routine procedure in cases of Escherichia coli gastroenteritis, current information regarding clinical and epidemiological aspects of infection by enterotoxigenic E. coli (ETEC) is lacking. This survey aimed at retrieving that information by conducting routine enterotoxigenicity tests in a clinical laboratory for patients suspected of E. coli gastroenteritis. METHODS: The survey population included 415 children < or = 2.5 years old with gastroenteritis, during the second half of 1992. Fresh first stool cultures were checked daily for toxigenicity by ELISA. Thereafter the serotypes, and the colonization factor antigens (CFAs) were evaluated for the ETEC strains. RESULTS: in 86 of the 415 children (20.7%) we found ETEC. Half these strains would have not been reported as pathogenic without this routine toxigenicity test. CFA were defined in 48 (55.8%) of the ETEC strains. The most common serogroups were O-153, O-6, O-126, and O-128.

Agglutination Tests↗
PubMed1994

Biochemical characterization of the mechanisms involved in the 5-hydroxytryptamine-induced increase in rat atrial rate.

Several possible mechanisms for 5-hydroxytryptamine (5-HT)-induced tachycardia in rat have been suggested: an activation of 5-HT1C or 5-HT2 receptors, an indirect sympathomimetic effect or a mechanism independent of 5-HT2 receptor stimulation. The aim of this study was to investigate the involvement of these mechanisms in the 5-HT-induced increase in rat atrial rate using biochemical methods. Indeed, the 5-HT1C and 5-HT2 receptors are linked to phosphoinositide hydrolysis and the noradrenaline (NA) released by 5-HT can stimulate the beta 1-adrenergic receptors linked to adenylate cyclase stimulation. The effect of varying concentrations of 5-HT on inositol phospholipid hydrolysis and adenylate cyclase activity of the rat isolated atria were measured. 5-HT (2 microM) did not modify total inositol phosphate (IP) production, while 5-HT 10 and 50 microM increased it 2-fold. The 5-HT2 antagonist ketanserin (1 microM) abolished IP accumulation induced by 5-HT microM), which indicates that this accumulation is 5-HT2 and not 5-HT1C receptor-mediated. Moreover, cyclic AMP (cAMP) formation was enhanced by 5-HT (5, 10, 20 and 50 microM). When atria were incubated 10 min with the beta-adrenergic receptor antagonist nadolol (1 microM), the increase in the cAMP level induced by 5-HT, whatever its concentration (10, 20 or 50 microM), was inhibited. Treating rats with reserpine (2.5 mg/kg, i.p., 48 and 24 hr before experimentation), which caused NA depletion in the heart, seemed to reduce the stimulating effect of 5-HT 10 and 50 microM on adenylate cyclase activity. Thus, the 5-HT-induced increase in cAMP is indirectly due to the activation of the beta-adrenergic receptors by the NA released by 5-HT. It is concluded that 5-HT stimulates both phosphoinositide turnover and adenylate cyclase activity in the rat isolated atria by activation of 5-HT2 receptors and by an indirect sympathomimetic effect.

Adenylyl Cyclases↗
PubMed1994

[CA 125 in diagnosis and prognosis of epithelial ovarian cancer].

In 59 women with epithelial ovarian cancer serum CA 125 was determined and they were then followed for 3 years. In those with active disease, mean serum CA 125 (289 units/ml) and positivity rate (85%) were significantly higher than in those without evidence of disease (44 units/ml and 17%, p = 0.001 and p < 0.001, respectively). Actuarial 3-year survival curves were calculated according to CA 125 serum level. 91% of those with CA 125 lower than 35 units/ml survived 3 years, as compared to 40% of those with CA 125 levels higher than 35 units/ml (p < 0.01). In ovarian cancer CA 125 serum level correlates with the state of the disease and can be used in the prediction of 3-year survival.

Actuarial Analysis↗