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Biomedical subjects

Y Cohen

Publications and source records attributed to Y Cohen.

At least 37 records · Page 2Linked to original sources
PubMed2002

Gonadotropin response to GnRH during sexual ontogeny in the common carp, Cyprinus carpio.

This study was designed to reveal whether gonadotropic response to GnRH in the common carp (Cyprinus carpio) changes during sexual ontogeny and whether the response of FSHbeta and LHbeta subunits is uniform or differential. The study comprised fish at the following stages: juveniles (4-month-old females with primary oocytes and early spermatogenic males); maturing (9-month-old previtellogenic females and advanced spermatogenic males); and mature (16-month-old postvitellogenic females and spermiating males). Fish were injected with superactive salmon GnRH analogue (sGnRHa; 25 microg/kg) and blood was sampled 6, 12 and 24 h later for cGtH (LH) and sex steroid levels. Pituitaries were taken for determination of FSHbeta and LHbeta mRNA levels by slot-blot hybridization and for cGTH content in the same glands by radioimmunoassay (RIA). Values were compared with the levels prior to sGnRHa administration and with control fish sampled at the same intervals. Juvenile fish did not respond at all to sGnRHa. In maturing females, FSHbeta mRNA increased by >300%, while that of LHbeta increased by 200%. In maturing males, FSHbeta mRNA did not change and only a slight increase occurred in that of LHbeta. In 16-month-old postvitellogenic females, there was no response of FSHbeta mRNA, while that of LHbeta dramatically increased. In spermiating males of the same age, mRNA of both FSHbeta and LHbeta increased following sGnRHa injection. Immunoreactive cGtH was present in the pituitary and plasma of all fish examined, but in juveniles it did not change following sGnRHa injection. In maturing and mature fish of both genders, sGnRHa administration was followed by a marked increase in circulating cGtH, concomitant with a decrease in its pituitary content, indicating the limited amount of the hormone stored in the gland. In conclusion, the response of the gonadotropin subunit mRNAs in the common carp was found to be differential and dependent on the gender and the phase of sexual ontogeny.

Age Factors↗
PubMed2002

Unusual cytomegalovirus complications after autologous stem cell transplantation for large B cell lymphoma: massive gastrointestinal hemorrhage followed by a communicating hydrocephalus.

Unusual cytomegalovirus (CMV)-related complications were seen after autologous stem cell transplantation (SCT) in a 50-year-old patient with diffuse large B cell lymphoma. One month after SCT, the patient developed life-threatening upper gastrointestinal tract (GIT) bleeding with several episodes of hemorrhagic shock. Endoscopy and subsequent explorative laparotomy revealed deep-seated bleeding ulcers containing intracellular CMV inclusion bodies distributed extensively in the GIT, from the lower esophagus to the small bowel. Later, she developed gradual loss of consciousness with communicating hydrocephalus which was possibly secondary to CMV-induced ventriculitis. She recovered completely after insertion of a ventriculostomy and subsequent V-P shunt.

Cerebral Ventricles↗
PubMed2002

The human tuftelin gene and the expression of tuftelin in mineralizing and nonmineralizing tissues.

Tuftelin has been suggested to play an important role during the development and mineralization of enamel, but its precise function is still unclear. This article reviews major milestones in the discovery, structural characterization, expression, localization, and conservation of tuftelin in different vertebrate species. It focuses on the structure of the human tuftelin gene, which has recently been deciphered [12]. It describes the exon-intron organization, sizes and structure, the promoter structure, and the newly discovered alternatively spliced human tooth-bud tuftelin mRNA transcripts. It also examines information on the structural motifs in the human-derived tuftelin protein and how they relate to tuftelin from other species. It reviews our recent results on the transcription of tuftelin mRNA and protein expression in several nonmineralizing soft tissues, using reverse-transcription polymerase chain reaction (RT-PCR) followed by DNA cloning and sequencing, indirect immunohistochemistry, immunohistochemistry combined with confocal microscopy, and in situ hybridization. These results and earlier Northern blot results show that tuftelin, in addition to being expressed in the developing and mineralizing tooth, is also expressed in several nonmineralizing soft tissues, suggesting that tuftelin has a universal function and/or a multifunctional role.

Alternative Splicing↗
PubMed2002

Retrospective comparison of single-agent chemotherapy with weekly 5-fluorouracil or weekly irinotecan in previously treated patients with metastatic colorectal cancer.

UNLABELLED: This study is a retrospective analysis of response, toxicity and freedom from progression of two single-agent chemotherapy regimens in patients with previously treated metastatic colorectal cancer. Thirty-five patients with histologically confirmed measurable metastatic colorectal cancer received chemotherapy after failure of first-line 5-fluorouracil (5-FU) and leucovorin treatment. The median age was 61 years. Twenty-seven patients had liver metastases, 6 had local recurrence, 1 had retroperitoneal lymph node metastases and 1 had lung metastases. Eighteen patients received weekly 2600 mg/m2 5-FU and 17 patients received weekly 125 mg/m2 irinotecan (CPT-11). Treatment was given until disease progression. Total number of cycles was 202 for 5-FU and 248 for CPT-11. The relative dose intensity was 1.0 for 5-FU and 0.84 for CPT-11. No grade 3-4 toxicity was registered in patients who received 5-FU. Grade 3-4 toxicity rates were as follows in those who received CPT-11: vomiting 1 (5.9%) patient in 1 cycle, diarrhea 3 (17.7%) patients in 3 cycles and neutropenia in 3 (17.7%) patients in 3 cycles. No patients manifested febrile neutropenia. Two patients (11.8%) needed hospital admission because of toxicity: 1 for vomiting and 1 for diarrhea. No objective responses were observed in the 5-FU group of patients. Three patients (17.6%) who received CPT-11, achieved partial response with a median duration of 8 months. Stable disease was registered in 3 (17.6%) and 9 (52.9%) patients in 5-FU and CPT-11 groups respectively (p=0.05). Median time to progression was 3.3 months for patients who received 5-FU and 4.2 months for those treated with CPT-11 (not significant). One-year survival was 22.2% and 54.3% respectively (p=0.05). CONCLUSION: Weekly chemotherapy with CPT-11 is tolerated with acceptable toxicity and leads to a better response rate than weekly high dose 5-FU. It also significantly improves survival but does not prolong freedom from progression.

Antimetabolites, Antineoplastic↗
PubMed2001

Sporotrichoid lymphangitis due to group A Streptococcus.

We describe what is, to our knowledge, the first case of sporotrichoid lymphangitis caused solely by group A Streptococcus in an otherwise healthy patient. Infection with pyogenic pathogens, such as streptococci and staphylococci, as well as with the most common causes of sporotrichoid lymphangitis (i.e., Sporothrix schenkii, Nocardia brasiliensis, Mycobacterium marinum, and Leishmania species) should be considered in differential diagnosis for some patients.

Humans↗
PubMed2001

Evidence of rainbow trout prolactin interaction with its receptor through unstable homodimerisation.

This study aims to characterise Prolactin receptor (PRLR) in rainbow trout for which no information is available despite the availability of Salmonid PRL preparations. By screening a freshwater rainbow trout intestine cDNA library with a probe corresponding to the extracellular domain (ECD) of tilapia PRLR, we have cloned a 2.5 kb insert coding for the PRLR. The mature protein of 614 amino acid residues is similar to PRLR isolated in tilapia and also the long form of mammalian PRLR. Analysis of PRLR gene expression in osmoregulatory organs revealed the presence of a unique transcript, thus confirming the involvement of this hormone in the control of osmoregulation in this fish species. By using surface plasmon resonance (SPR) technology, kinetic measurement of interaction between trout PRL and its receptor ECD was studied. This approach allowed us to demonstrate the formation of a transient, unstable homodimeric complex. This unstability could explain the inability to perform binding experiments using homologous PRL. In contrast, heterologous lactogenic ligands were able to interact through a more stable complex. Whether these characteristics of PRL-receptor interaction in rainbow trout are different to what occurs in tilapia where a homologous radioreceptor assay was developed would require further studies.

Animals↗
PubMed2001

Transplanted lichens in and around the Mount Carmel National Park and the Haifa Bay industrial region in Israel: physiological and chemical responses.

This study investigated the impact of air pollution on the spectral reflectance of the epiphytic lichen Ramalina lacera, indicated by the normalized difference vegetation index (NDVI), on the integrity of chlorophyll, indicated by the ratio OD435 nm/OD415 nm, and on the integrity of cell membranes, indicated by electric conductivity. Data relating to physiological parameters of injury were integrated with data concerning the detrimental deposition of mineral elements. The transplanted lichen, originating in a relatively unpolluted site in Israel, was placed in 17 sites on and around the Carmel Mountain and in 2 sites in an industrial region in the Haifa Bay, northwest Israel, for a period of 10 months. The accumulated amounts of Ca, Ti, Cu, Mg, Fe, Si, Ni, Zn, V, Cr, Mn, Cl-, K, F-, Na, Ba, Sr, B, S, P, Al, PO(3-)(4), SO(2-)(4), and NO-3 were related to alterations in spectral reflectance and injury caused to chlorophyll and cell membranes. At the end of the period of exposure, the retrieved transplants from the Haifa Bay exhibited low NDVI values and low OD435 nm/OD415 nm ratios, indicating chlorophyll degradation, and high electric conductivity values, indicating damaged cell membranes. NDVI values correlated positively with OD435 nm/OD415 nm ratios and negatively with accumulated amounts of Ba, Cu, Ni, S, SO(2-)(4), V, and Zn. OD435 nm/OD415 nm ratios correlated negatively with amounts of Ba, Cu, Ni, NO(-)(3), SO(2-)(4), and V. Values obtained for electric conductivity correlated positively with amounts of B, Ba, Cl-, Cr, Cu, Na, Ni, NO(-)(3), S, and SO(2-)(4). Both elemental and ion content and the physiological status of the R. lacera transplants indicated that the greater part of the biomonitoring sites on and around the Carmel Mountain were slightly polluted or unpolluted, whereas the Haifa Bay region was rather polluted. The greater part of the Haifa Bay pollution derives from the combustion of heavy fuel oil.

Cell Membrane↗
PubMed2001

Accuracy of a composite score using daily SAPS II and LOD scores for predicting hospital mortality in ICU patients hospitalized for more than 72 h.

UNLABELLED: In most databases used to build general severity scores the median duration of intensive care unit (ICU) stay is less than 3 days. Consequently, these scores are not the most appropriate tools for measuring prognosis in studies dealing with ICU patients hospitalized for more than 72 h. PURPOSE: To develop a new prognostic model based on a general severity score (SAPS II), an organ dysfunction score (LOD) and evolution of both scores during the first 3 days of ICU stay. DESIGN: Prospective multicenter study. SETTING: Twenty-eight intensive care units (ICUs) in France. PATIENTS: A training data-set was created with four ICUs during an 18-month period (893 patients). Seventy percent of the patients were medical (628) aged 66 years. The median SAPS II was 38. The ICU and hospital mortality rates were 22.7% and 30%, respectively. Forty-seven percent (420 patients) were transferred from hospital wards. In this population, the calibration (Hosmer-Lemeshow chi-square: 37.4, P = 0.001) and the discrimination [area under the ROC curves: 0.744 (95 % CI: 0.714-0.773)] of the original SAPS II were relatively poor. A validation data set was created with a random panel of 24 French ICUs during March 1999 (312 patients). MEASUREMENTS AND MAIN RESULTS: The LOD and SAPS II scores were calculated during the first (SAPS1, LOD1), second (SAPS2, LOD2), and third (SAPS3, LOD3) calendar days. The LOD and SAPS scores alterations were assigned the value "1" when scores increased with time and "0" otherwise. A multivariable logistic regression model was used to select variables measured during the first three calendar days, and independently associated with death. Selected variables were: SAPS II at admission [OR: 1.04 (95 % CI: 1.027-1.053) per point], LOD [OR: 1.16 (95 % CI: 1.085-1.253) per point], transfer from ward [OR: 1.74 (95 % CI: 1.25-2.42)], as well as SAPS3-SAPS2 alterations [OR: 1.516 (95 % CI: 1.04-2.22)], and LOD3-LOD2 alterations [OR: 2.00 (95 % CI: 1.29-3.11)]. The final model has good calibration and discrimination properties in the training data set [area under the ROC curve: 0.794 (95 % CI: 0.766-0.820), Hosmer-Lemeshow C statistic: 5.56, P = 0.7]. In the validation data set, the model maintained good accuracy [area under the ROC curve: 0.826 (95 % CI: 0.780-0.867), Hosmer-Lemeshow C statistic: 7.14, P = 0.5]. CONCLUSIONS: The new model using SAPS II and LOD and their evolution during the first calendar days has good discrimination and calibration properties. We propose its use for benchmarking and evaluating the over-risk of death associated with ICU-acquired nosocomial infections.

APACHE↗
PubMed2001

Biofiltration--the treatment of fluids by microorganisms immobilized into the filter bedding material: a review.

Biofiltration is distinguished from other biological waste treatments by the fact that there is a separation between the microorganisms and the treated waste. In biofiltration systems the microorganisms are immobilized to the bedding material, while the treated fluid flows through it. In recent decades, a vast amount of literature has been written on single experiments involving the treatment of fluids by immobilized microorganisms. Several artificial immobilization methods have been examined and impressive results have been achieved in the treatment of fluids with one of the artificial immobilization methods the entrapment of microorganisms within polymer beads. This method, even though it needs to be improved, seems to have a future potential in commercial biofiltration systems. The methods of artificial immobilization of microorganisms within biofiltration systems have several advantages, but also suffer from several disadvantages in comparison to the treatment of fluids by naturally attached microorganisms. Understanding the mechanisms and forces responsible for the attachment of microbes to the bedding material, in attempt to improve this attachment, is of the utmost importance. Further improvement of the artificial entrapment of microorganisms within polymers will allow the exploitation of the advantages of this method in the treatment of fluids. The aim of this review essay is to introduce the main principles of two immobilization processes - the self-attachment of microorganisms to the bedding material and the artificial entrapment of microorganisms within polymer beads. Both treatments of liquids and gases with each immobilization process are discussed. The advantages and disadvantages of each immobilization process are pointed out and different aspects of the fluid treatment with the two immobilization processes are compared.

Biofilms↗
PubMed2001

Early childhood traumatic development and its impact on gender identity.

The author clarifies issues of gender identity typical to contemporary Western societies. Nowadays, we tend to emphasize self-autonomy as the main target of the individual's development. In adolescence this may cause many questions as to the adolescent's conception of his or her gender and sexual identity. These questions are the outcome of early development, and thus early traumas may impact the entire gender development. In this context, trauma includes not only major violations such as sexual abuse, terror attacks, and so forth, but also comprises events heretofore considered minor.

Adolescent↗
PubMed2001

Kidney involvement and renal manifestations in non-Hodgkin's lymphoma and lymphocytic leukemia: a retrospective study in 700 patients.

Renal involvement as part of systemic lymphoma (LY) is quite frequent, however, primary extranodal renal non-Hodgkin's lymphoma (NHL) is extremely rare, and only about 65 cases have been reported in the world literature. In a retrospective study of renal manifestations in 700 patients with documented LY and chronic lymphocytic leukemia (CLL) seen at our hospital during 1986-95, 83 patients had signs of acute renal failure. Only five of these had proven renal infiltration, but none of them satisfied the criteria for primary renal LY. Glomerulonephritis (GN) has also rarely been reported in association with LY and CLL, and only 37 glomerular lesions in NHL and 42 in CLL have been documented, respectively. GN may precede, coexist, or follow the diagnosis of LY by several years. Of the 42 cases of CLL reported worldwide, 36 had nephrotic syndrome. Renal failure was seen in about one third. The most common glomerular lesion reported is membranoproliferative GN, followed by membranous GN. In our study, we found only five biopsy-proven cases with GN amongst the 700 patients seen. In this report we also briefly describe some rare interesting associated renal syndromes in CLL and NHL.

Acute Kidney Injury↗
PubMed2001

Multimodal treatment of metastatic thymic carcinoma including high-dose chemotherapy with autologous stem cell transplantation: report of a case with more than 4-year disease-free survival.

Thymic carcinoma is a rare epithelial malignancy differentiated from thymoma by the presence of cytologically malignant cells. There are few reports of the treatment of locally advanced or metastatic thymic carcinoma. We describe a patient who sought treatment for thymic carcinoma metastatic to pleura, pericardium, retroperitoneum, and neck nodes. He was treated with neoadjuvant etoposide, ifosfamide, and cisplatin, and underwent resection. We then administered high-dose chemotherapy with autologous stem cell support, followed by radiation therapy. The patient remains in complete remission more than 4 years after diagnosis. To our knowledge, this is the first report of metastatic thymic carcinoma treated with neoadjuvant therapy and postoperative high-dose chemotherapy. Metastatic thymic carcinoma may be curable by aggressive combined therapies.

Adult↗