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Biomedical subjects

Y Cohen

Publications and source records attributed to Y Cohen.

At least 109 records · Page 6Linked to original sources
PubMed1998

Peritoneal papillary serous carcinoma: study of 15 cases and comparison with stage III-IV ovarian papillary serous carcinoma.

BACKGROUND AND OBJECTIVES: Peritoneal papillary serous carcinoma (PPSC) is histologically and clinically similar to stage III-IV ovarian papillary serous carcinoma (OPSC). The purpose of this study was to investigate the clinical findings, treatment, and outcome of PPSC patients compared with stage III-IV OPSC patients. METHODS: Data from the files of 15 PPSC patients and 52 stage III-IV OPSC patients who were managed at the Soroka Medical Center between January 1991 and December 1997 were evaluated. RESULTS: With regard to patients' characteristics, presenting signs and symptoms, type and extent of surgery, tumor response to first-line chemotherapy, recurrence-free interval, recurrence site, tumor response to second-line chemotherapy, and serum CA-125 levels, no significant differences were observed between the PPSC patients and the stage III-IV OPSC controls. The prevailing presenting symptoms were abdominal mass and ascites. The mainstay of treatment was debulking surgery followed by adjuvant platinum-containing chemotherapy. The objective response rate to first-line chemotherapy was 80%. The actuarial 5-year survival rate for the PPSC patients and stage III-IV OPSC patients was 52.0% and 20.5%, respectively (0.05 < P < 0.1). CONCLUSIONS: The clinical and surgical characteristics of patients with PPSC are similar to those of patients with stage III-IV OPSC. When treatment strategies for stage III-IV OPSC are applied to PPSC, the survival of PPSC patients may be similar or even better than that of stage III-IV OPSC patients.

Chemotherapy, Adjuvant↗
PubMed1998

In vivo and in vitro bi-exponential diffusion of N-acetyl aspartate (NAA) in rat brain: a potential structural probe?

Diffusion measurements were performed on the N-acetyl aspartate (NAA) signal in in situ brains (in vivo and post-mortem) and on in vitro brain tissue at 37 degrees C using wide ranges of b-values (from 0 up to 4.5 x 10(6) s/cm2 and 35.8 x 10(6) s/cm2 for the in vivo and the in vitro cases, respectively). In vivo and in vitro NAA signals attenuation due to diffusion was measured at fixed diffusion times (tD). In the in vitro cases the effect of tD on the apparent diffusion coefficients (ADCs) of NAA was evaluated. From these experiments the following observations and conclusions were made: (1) NAA signal attenuation both in vivo and in vitro is not mono-exponential and could be fitted by bi-exponential fitting function; (2) analysis of the low b-value range only (up to 0.5 x 10(6) s/cm2) gives a mono-exponential decay (r = 0.999); (3) in both cases the obtained ADCs are sensitive to the diffusion time; (4) the ADCs of the pre- and post-mortem cases are nearly similar; (5) the ADCs obtained from the bi-exponential fitting function decrease when the diffusion time increases; and (6) both the fast and the slow diffusing components of NAA show a considerable restriction by what seems to be a non-permeable barrier from which two compartments were identified, one having a size of 6-8 microns and the other of approximately 1-2 microns in size. It seems conceivable that the two populations identified in the diffusion experiments represent primarily the NAA in the cell body (soma) and in the neurital space (axons and proximal dendrites).

Animals↗
PubMed1998

Non-mono-exponential attenuation of water and N-acetyl aspartate signals due to diffusion in brain tissue.

Diffusion measurements were performed on water and N-acetyl aspartate (NAA) molecules in excised brain tissue using a wide range of b-values (up to 28.3 x 10(6) and 35.8 x 10(6) s cm-2 for water and NAA, respectively). The attenuation of the signals of water and NAA due to diffusion was measured at fixed diffusion times (tD). These measurements, in which the echo time (TE) was set to 70 ms, were repeated for several diffusion times ranging from 35 to 305 ms. Signal attenuations were fitted to mono-, bi-, and triexponential functions to obtain the apparent diffusion coefficients (ADCs) of these molecules at each diffusion time. From these experiments the following observations and conclusions were made: (1) Signal attenuation of water and NAA due to diffusion over the entire range of b values examined is not monoexponential and the extracted ADCs depend on the diffusion time; (2) In the case of water the experimental data are best fitted by a triexponential function, while for b values up to 1 x 10(6) s cm-2, a biexponential function seems to reproduce the experimental data as well as the triexponential function; (3) If only the low range of b values are fitted (up to 0.5 x 10(6) s cm-2) signal attenuation of water is monoexponential and insensitive to tD; (4) Water ADCs decreased with the increase in tD but the relative population of the fast diffusing component increases such that at a tD of 305 ms there is nearly a single population; (5) The major fast diffusion component of the water shows only very limited restriction; (6) NAA signal attenuation is biexponential and analysis of the low b-value range gives only monoexponential decay, but the obtained ADC is sensitive to the diffusion time; (7) The ADCs obtained from fitting the data with a biexponential function decrease as diffusion time increases; (8) The relative population of the slow-diffusing component decreases with increasing tD; (9) Both the fast and the slow diffusing components of NAA show a considerable restriction by what seems to be a nonpermeable barrier from which two compartments, one of 7-8 micron and one of approximately 1 micron, were calculated using the Einstein equation. It is suggested that the two compartments represent the NAA in cell bodies and in the intra-axonal space. The effect of the range of the b value used in the diffusion experiments on the results is discussed and used to reconcile some of the apparent discrepancies obtained in different experiments concerning water diffusion in brain tissue. The potential of NAA diffusion experiments to probe cellular structure is discussed.

Algorithms↗
PubMed1998

Comparison between levels of trace elements in normal and cancer inoculated mice by XRF and PIXE.

Determination of Rb, Br, Se, Zn, Cu, Fe, and Br/Rb ratio in tissues of mice inoculated with colon and melanoma cancer cells is described. A group of 19 Balb/c mice inoculated with C26 colon carcinoma, 4 C57B1/6 mice inoculated with B16 melanoma, and 13 control mice of both kinds were under investigation. The study was conducted on samples of blood, liver, kidneys, colon, and skin, and the trace element levels in normal and inoculated mice were compared. The inoculation was by subcutaneous injection either at the back or intrafootpad. The blood samples were taken 1, 2, and 3 wk after inoculation, and after 4 wk all the animals were sacrificed. Two nondestructive, complementary analytical methods were used: a modified X-ray fluorescence (XRF) for solid tissue and particle-induced X-ray emission (PIXE) for blood samples. The detection limit (DL) in the PIXE method was 0.35 microg/g dry wt in 600 s counting time and in XRF, 1 microg/g dry sample for Rb, Br, Se and Zn and 2 microg/g for Cu and Fe in 200 s counting time. In all the cases studied, cancerous tissue developed at the site of the injection, and a significant difference in the trace element levels was observed between tissue samples obtained from normal and inoculated mice. The most pronounced effect was an increase in Rb level in the tumor by a factor ranging between 4 and 10 relative to normal tissue, with a corresponding decrease in the Br/Rb ratio (p < 0.05). Smaller changes were found in the Br, Se, Zn, and K levels. The changes in trace element levels in the inner organs were much smaller and seem to be influenced by the site of injection.

Animals↗
PubMed1998

Cancer morbidity in psychiatric patients: influence of lithium carbonate treatment.

The relationship between mental diseases and cancer development has been examined in a number of studies but the findings are still inconclusive and suffer from methodological problems. Studies conducted to examine the effect of lithium on malignant cells yielded inconsistent results. The study group included 609 patients treated by lithium carbonate and 2396 controls. A lower but non significant risk (RR = 0.79; CI = 0.17-3.60) to develop non-epithelial tumors was found among lithium carbonate treated psychiatric patients as compared to controls. A significantly (P = 0.05) inverse trend of cancer with lithium dose was observed. The risk of cancer development among each group of psychiatric patients was significantly lower than in the general population (RR = 0.68 for the lithium treated group versus 0.78 for controls). Mental patients have a lower cancer prevalence than the general population and lithium may have a protective effect.

Adult↗
PubMed1998

Integrity of Lichen Cell Membranes in Relation to Concentration of Airborne Elements

This study dealt with the impact of air pollution on the integrity of cell membranes in the lichen Ramalina duriaei. The lichen was transplanted from a relatively unpolluted site in Israel to more polluted sites, adjacent to a 40-year-old town, for a period of 10 months. The concentrations of K, B, Al, Cr, Fe, Si, Ti, Zn, P, Ba, Cu, Mg, Na, Pb, Ca, Mn, Sr, and S in lichen thalli were compared with injury caused to the cell membranes. The study indicates that electric conductivity reflects adequately cellular injury to lichen thalli transplanted to sites near a motorway, an oil-fueled power plant and a rural community (a kibbutz). The concentrations of S, B, Al, Cr, Fe, Si, Ti, and Zn correlated with injury in cell membranes of R. duriaei retrieved from the biomonitoring sites, whereas the concentration of K in the thalli correlated inversely with the electric conductivity parameter. Leakage of K from lichen thalli as a result of air pollutants is suggested. This K leakage correlates positively with concentrations of S and Cr in transplants of R. duriaei to the Ashdod region.

Journal Article↗
PubMed1998

Extramammary Paget's disease recurring on the skin of the lower abdomen and entire right leg two and half years after simple vulvectomy for minimally invasive Paget's disease of the vulva.

We encountered an unusual case of extramammary Paget's disease (EMPD) recurring on the skin of the lower abdomen and entire right leg two and a half years after simple vulvectomy for minimally invasive Paget's disease of the vulva. Histologic examination of the skin metastases demonstrated that the proliferation of Paget cells was confined to the dermis, most of them were located in lymphatic vascular spaces. This case confirms that minimally invasive Paget's disease of the vulva may sometimes be an aggressive disease. We consider that lymphatic metastases already existed in this patient at the time of initial surgery; thus, the recurrence of EMPD on extragenital skin sites may have been prevented if initial treatment would have included radical vulvectomy and bilateral groin lymph node dissection instead of simple vulvectomy without groin lymph node dissection.

Abdomen↗
PubMed1998

Uterine papillary serous carcinoma: study of 19 cases.

OBJECTIVE: Uterine papillary serous carcinoma (UPSC) is an uncommon highly malignant variant of endometrial carcinoma that histologically and clinically resembles ovarian papillary serous carcinoma. The purpose of this study was to present the conjoined experience of two regional hospitals in the south of Israel (Soroka Medical Center, Beer-Sheva and Kaplan Hospital, Rehovot) of handling this tumour. STUDY DESIGN: Data from the files of 19 patients with UPSC who were managed at these hospitals between July 1991 and June 1997 were evaluated. RESULTS: The three-year survival rate was 57.3% overall; 83.3% for Stage I and 21.2% for Stages II, III, and IV combined (P<0.02). Eighteen patients had primary surgery which included total abdominal hysterectomy and bilateral salpingo-oophorectomy and 15 (83.3%) of them received postoperative adjuvant therapy which included radiotherapy and/or systemic chemotherapy. CONCLUSIONS: The prognosis of patients with UPSC is worse than that of patients with other forms of endometrial carcinoma. Primary surgery comprised of total abdominal hysterectomy, bilateral salpingo-oophorectomy and staging is the mainstay of treatment. The type of postoperative treatment is not consistent. By and large, adjuvant pelvic radiotherapy is usually given in early-stage disease and adjuvant systemic chemotherapy is usually prescribed in advanced-stage disease.

Adult↗
PubMed1998

Metastatic angiosarcoma of the spleen after accidental radiation exposure: a case report.

Angiosarcoma is a rare malignant tumor arising from endothelial cells of blood vessels or lymphatic channels. Therapeutic irradiation, thoriumdioxide administration, pyothorax, and polyvinyl chloride exposure have been shown to be predisposing factors for developing angiosarcoma. Accidental radiation exposure has not been associated with angiosarcoma. We present an unusual case of angiosarcoma of the spleen, with metastases to bone, liver, breast, and bone marrow, in a woman who lived near the Chernobyl nuclear facility in the former Soviet Union at the time of the reactor accident in 1986. To the best of our knowledge, this is the first report of metastatic angiosarcoma after accidental radiation exposure.

Female↗
PubMed1998

Sulfate-reducing bacteria and their activities in cyanobacterial mats of solar lake (Sinai, Egypt).

The sulfate-reducing bacteria within the surface layer of the hypersaline cyanobacterial mat of Solar Lake (Sinai, Egypt) were investigated with combined microbiological, molecular, and biogeochemical approaches. The diurnally oxic surface layer contained between 10(6) and 10(7) cultivable sulfate-reducing bacteria ml-1 and showed sulfate reduction rates between 1,000 and 2, 200 nmol ml-1 day-1, both in the same range as and sometimes higher than those in anaerobic deeper mat layers. In the oxic surface layer and in the mat layers below, filamentous sulfate-reducing Desulfonema bacteria were found in variable densities of 10(4) to 10(6) cells ml-1. A Desulfonema-related, diurnally migrating bacterium was detected with PCR and denaturing gradient gel electrophoresis within and below the oxic surface layer. Facultative aerobic respiration, filamentous morphology, motility, diurnal migration, and aggregate formation were the most conspicuous adaptations of Solar Lake sulfate-reducing bacteria to the mat matrix and to diurnal oxygen stress. A comparison of sulfate reduction rates within the mat and previously published photosynthesis rates showed that CO2 from sulfate reduction in the upper 5 mm accounted for 7 to 8% of the total photosynthetic CO2 demand of the mat.

Bacteria↗
PubMed1998

The "hands-off" catheter and the prevention of systemic infections associated with pulmonary artery catheter: a prospective study.

The Arrow "Hands-Off" thermodilution catheter (AHO) is completely shielded during balloon testing, preparation, and insertion. To assess the value of the AHO in the prevention of systemic infections associated with pulmonary artery catheterization (SIAPAC), we conducted a randomized prospective study over an 18-mo period. The patients were randomly assigned to two groups, of which one received the thermodilution catheter routinely used in our department and the other, the AHO catheter. The diagnosis of SIAPAC was based on recovery of the same organism from the thermodilution catheter (TC) and blood samples, absence of any other infectious focus, and improvement or resolution of clinical evidence of infection after removal of the TC. A total of 166 TCs were randomized in 150 patients. The two groups (mean +/- SD) were comparable in terms of age, SAPS on admission (15.6 +/- 5.2 versus 15.2 +/- 6.2), SAPS on the day of catheter insertion (17.6 +/- 4.8 versus 17.3 +/- 5.8), duration of catheter insertion (22.8 +/- 11.3 versus 25.3 +/- 19.5 min), insertion site, hemodynamic status, duration of use of the TC (3.6 +/- 1.3 versus 3.5 +/- 1.5 d), and outcome. A total of eight cases of SIAPAC were diagnosed in the standard TC group, versus none in the AHO group (p < 0.002). No cases of SIAPAC occurred in those patients who had their TC for less than four days. This study demonstrates the value of the AHO for preventing systemic infections associated with prolonged pulmonary artery catheterization.

Aged↗
PubMed1998

Plasmodesmata: gateways for information transfer.

Intercellular communication in plants has evolved to occur via elongated cytoplasmic bridges, called plasmodesmata, that traverse the thick cell walls that surround plant cells. Historically, plasmodesmata have been assigned the mostly passive role of creating cytoplasmic continuity between plant cells enabling free transport of the wealth of small plant metabolites and growth hormones under 1 kDa. When it was discovered that plant viruses pirate plasmodesmata for movement of viral genomes during infection, it was proposed that viruses modified plasmodesmata for transport of very large molecules. Now, there is compelling evidence that plasmodesmata are inherently dynamic, rapidly altering their dimensions to increase their transport capabilities, upon contact with viral as well as developmentally important plant proteins. Further, the study of intercellular transport has prompted analyses of intracellular transport pathways, implicating the cytoskeleton as a major tracking system to plasmodesmata. Thus, plasmodesmata form a three-dimensional network of transportation channels and major checkpoints for information transfer. In the following, current knowledge about structure and function of these connective organelles, and about routing of molecules towards plasmodesmata, will be summarized.

Biological Transport↗
PubMed1998

Primary squamous cell carcinoma of the vagina: report of four cases and review of the literature.

Four patients with primary vaginal invasive squamous cell carcinoma are reported. They accounted for 0.3% of all females with genital tract malignancies diagnosed in the south of Israel between 1961 and 1996. One patient had Stage I disease, one--Stage II, one--Stage III and one--Stage IV. One patient was treated with external radiotherapy followed by intracavitary brachytherapy, one patient was treated with external radiotherapy followed by interstitial brachytherapy, one patient had systemic chemotherapy and one patient had no treatment. At the time of writing, one patient was alive without disease, one was alive with progressive disease, one had died of disease and one had died of intercurrent disease. It is concluded that primary vaginal carcinoma is a very rare entity with an estimated incidence of about 0.1-0.2/100,000 women. Most patients present with tumor extending beyond the vaginal wall (Stage II, III and IV) and the mainstay of treatment for these patients is radiotherapy. The overall 5-year survival rate is about 50%.

Adult↗
PubMed1998

Primary sarcoma of the ovary: report of five cases and review of the literature.

Primary ovarian sarcomas are rare and usually behave very aggressively. Over a ten-year period (1987-1996) five cases of primary ovarian sarcoma were managed at the Soroka Medical Center, Beer-Sheva, Israel. Four patients had malignant mullerian-mixed mesodermal tumor (MMMMT): two had Stage IIIC tumor with chondrosarcoma being the predominant sarcomatous element, one had Stage IIIC tumor with high-grade endometrioid stromal sarcoma (ESS) being the predominant sarcomatous element and one had Stage IC tumor with rhabdomyosarcoma being the predominant sarcomatous element. One patient had Stage IA leiomyosarcoma (LMS). All four patients with MMMMT received postoperative adjuvant chemotherapy, whereas the patient with LMS did not. The four patients with MMMMT died of their disease 10, 10, 13 and 25 months, respectively, after initial surgery. The patient with LMS died of intercurrent disease 21 months after initial surgery. It is concluded that most patients with primary ovarian sarcoma present with extraovarian disease and the prognosis is poor. The mainstay of treatment is debulking surgery consisting of total abdominal hysterectomy, bilateral salpingo-oophorectomy and extirpation of tumor masses. The benefit of postoperative adjuvant chemotherapy and/or radiotherapy is still a subject of debate and has yet not been established.

Aged↗
PubMed1997

[Radiotherapy of localized prostatic carcinoma].

112 patients with localized prostate cancer, clinical stage A2-C, were treated by definitive radiotherapy between 1982-1988. Radiation volume encompassed the prostate, seminal vesicles and pelvic lymph nodes. The 10-year actuarial survival figures were: overall 51%; stage A2 87%; stage B 50%; stage C 36%; well differential tumors 67%; moderately differentiated 50%; poorly differentiated 32%; patients with local tumor control 55%; and patients with minimal local control 36%. It is concluded that external beam irradiation is effective in localized prostatic cancer. Stage and grade are prognosticators of survival.

Aged↗
PubMed1997

[Initial evaluation of thoracic injuries. Comparison of pulmonary radiography and x-ray computed tomography].

OBJECTIVES: To investigate the contribution of computed tomography scan (CTS) to the initial évaluation of chest trauma. PATIENTS AND METHODS: We carried out a two-year prospective study in all the chest trauma patients admitted to ICU. They underwent both Chest X-ray (CXR) and CTS within 24 jours of admission. CXR and CTS images were read by achieving a consensus between two radiologists who were unaware of the results of the other investigation. Then we compared these findings with the treatment received by the patients in the ICU. RESULTS: From July 1, 1991 through July 1, 1993, 56 patients were included (21 with conventional CTS and 35 with helicoidal CTS). CTS demonstrated a significant number of pleural (p < 0.001), parenchymatous (p < 0.001), and mediastinal (p < 0.01) lesions that escaped detection on CXR (CTS+/CXR- lesions). Thoracic drainage was done in 16 patients because of abnormalities CTS+/CXR- (p < 0.01); six patients with CTS+/CXR- pulmonary contusions received Pressure Positive Ventilation (p < 0.01); and four CTS+/CXR- lesions were treated surgically (p < 0.05). CONCLUSION: CTS adds significantly to the evaluation of chest trauma by allowing prompt, accurate assessment of lesions. In this study, over 50% of these lesions required specific treatment during the ICU stay.

Adolescent↗
PubMed1997

Uterine sarcoma in the south of Israel: study of 36 cases.

BACKGROUND: Uterine sarcomas are rare, charaterized by rapid clinical progression and poor prognosis, and their management has been a challenge. The purpose of this study was to investigate the clinical and histologic findings, treatment, and outcome of patients with uterine sarcoma in the south of Israel. METHODS: Data from the files of 36 patients with uterine sarcoma who were managed at the Soroka Medical Center between January 1961 and December 1994 were evaluated. RESULTS: The 5-year survival rate was 32% overall; 63% for 9 patients with endometrial stromal sarcoma (ESS). 30% for 14 patients with mixed mesodermal sarcoma (MMS) and 18% for 13 patients with leiomyosarcoma (LMS): 41% for 22 patients with Stage I and 19% for 14 patients with Stages II, III, and IV. Only the difference in the 5-year survival rate between ESS and LMS was statistically significant (P < 0.05). Eleven patients (30.6%) were treated with surgery alone, 4 (11.1%) with surgery followed by pelvic radiotherapy, 11 (30.6%) with surgery followed by chemotherapy, 8 (22.2%) with surgery followed by pelvic radiotherapy and chemotherapy, one (2.8%) with chemotherapy alone, and one (2.8%) had no treatment. CONCLUSIONS: Uterine sarcomas are aggressive tumors with a poor prognosis. The treatment is surgery generally followed by adjuvant pelvic radiotherapy and/or systemic chemotherapy.

Adult↗