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Biomedical subjects

J Cohen

Publications and source records attributed to J Cohen.

At least 1,135 records · Page 63Linked to original sources
PubMed1988

Anonymous and non-anonymous oocyte donation preliminary results.

During the past year, we have developed an oocyte donation programme in 10 patients with complete absence of endogenous ovarian function (premature ovarian failure in seven cases, castration in two cases and Turner's syndrome in one case). In cases of anonymous donation, donors were volunteers devoid of any major genetical risk who were included in our IVF programme and who consented to donate one oocyte when at least seven oocytes were recovered, and two oocytes when at least 11 oocytes were recovered, to a recipient couple. As far as possible, morphological characteristics of both couples were paired. In cases of non-anonymous donation, donors were 'affective' donors, having at least one child. The resulting embryos after IVF of donated oocytes were either replaced directly in recipient women which required synchronization of the donor's and recipient's cycles, or cryopreserved and then thawed, usually at day 16 of recipient's artificial cycle, i.e. 2 days after introduction of the progestational compound. On the 10 patients entering this oocyte donation programme (20 cycles), 13 transfers were carried out resulting in four clinical pregnancies in three patients with premature ovarian failure and one with Turner's syndrome (20% pregnancy per cycle and 31% per transfer). Despite the small numbers, these good results prompted us to develop this protocol.

Adult↗
PubMed1988

Chromosome analysis of human oocytes and embryos: does delayed fertilization increase chromosome imbalance?

Thirty per cent of a sample of 120 unfertilized human oocytes carried chromosome abnormalities highly correlated with maternal age (38% in patients greater than 35, as compared with 24% in younger patients). Fertilized eggs, when observed 17 h after insemination, showed in 1.6% a single pronucleus suggesting parthenogenetic activation. In 92% of the cases two pronuclei were observed and the rate of chromosome anomalies depended on the morphological aspect of the embryos. Triploidy was also encountered in 6.4% of the eggs leading to an overall rate of chromosome aberrations reaching 29.2%. Delayed fertilization drastically increased the rate of chromosome anomalies (87%) as well as the rate of mosaicism: 30% versus 10.6% in timely fertilized eggs. The high rate of chromosome disorders in early life after in-vitro fertilization (IVF) raises the ethical question of the opportunity of carrying out a genetic control of normality in human embryos at the preimplantation stage.

Chromosome Aberrations↗
PubMed1988

Experience with diagnosis and treatment of sterility due to abnormality of the infundibulum of the Fallopian tube.

The diagnosis and treatment of sterility due to abnormalities of the infundibulum of the Fallopian tube are reviewed. Knowledge on the physiology of the distal part of the tube explains the mechanisms of sterility when a lesion occurs, although diagnosis is based mainly on hysterosalpingography and laparoscopy. The requisite treatments are either percoelioscopic or surgical, and techniques and results with these treatments are reviewed. Special attention is given to tubal stenosis as a consequence of embryonic cysts of the tube.

Fallopian Tubes↗
PubMed1988

Contribution of in-vitro fertilization to classical ovulation induction.

Enormous progress has been made in the induction of follicular growth in the context of IVF. This has led to a better understanding of the physiology of follicular maturation and to a better use of HMG and FSH for classical ovulation induction used for infertile couples. Six points are discussed: (i) criteria for monitoring ovulation; (ii) when to start treatment; (iii) significance of a premature LH surge; (iv) the dose of HMG; (v) the dose and results of pure FSH; and (vi) analogues of LHRH. IVF has modified our classical therapeutic habits and has led to an increased efficiency in gonadotrophin treatments of infertility.

Female↗
PubMed1988

Financial risk, hospital cost, complications, and comorbidities in surgical noncomplication- and noncomorbidity-stratified diagnostic related groups.

The purpose of this study was to analyze resource consumption in the 147 non-complicating condition-stratified surgical diagnostic related groups (DRGs). Analysis of 2647 surgical patients in these non-CC-stratified surgical DRGs demonstrated that patients with more CCs per DRG generated higher total hospital costs, a longer hospital length of stay, a greater percentage of procedures per patient, financial risk under DRG payment, more outliers, and a higher mortality rates than patients in these same DRGs with fewer CCs. These findings suggest that the current DRG classification system may be inequitable to certain groups of patients or types of hospitals vis-à-vis the non-CC-stratified surgical DRGs. Financial disincentives to treat these patients may affect both their access and quality of care in the future.

Academic Medical Centers↗
PubMed1988

Analysis of the structural polypeptides of a porcine group C rotavirus.

Polyacrylamide gel analysis of the structural polypeptides of purified group C virions allowed six major proteins to be identified. Of these, two (52,000- and 39,000-molecular-weight polypeptides) were shown to be in the outer virion shell as judged by the ability to strip them from virions by treatment with EDTA. Treatment of purified particles with endo-beta-N-acetylglucosaminidase F showed that the 39,000-molecular-weight outer shell polypeptide is probably posttranslationally glycosylated. Serological cross-comparison of groups A and C by using Western blotting (immunoblotting) extended the previously demonstrated lack of cross-reaction for the group antigen to show that none of the structural polypeptides cross-reacted. Possible implications of these findings for the epidemiology of rotaviruses are discussed.

Animals↗
PubMed1988

US characteristics of frozen prostate.

Cryosurgery has previously been used successfully to treat prostatic carcinoma. Inability to monitor the freezing led to local complications that limited the use of this modality. In this animal study, monitoring of the freezing process was accomplished with real-time ultrasound. The margin of the frozen tissue appeared as a hyperechoic rim with posterior acoustic shadowing. The thawed cryolesions showed markedly decreased echogenicity compared with normal unfrozen prostate. These characteristic changes should allow safer and more efficacious application of prostatic cryosurgery.

Animals↗
PubMed1988

Financial risk, hospital cost, and complications and comorbidities (CCs) in the non-CC-stratified pulmonary medicine diagnostic-related group Medicare hospital payment system.

The purpose of this study was to analyze hospital resource consumption in the 8 noncomplicating condition-stratified pulmonary medicine diagnostic-related groups (DRGs). We analyzed 427 Medicare patients treated during a 2-yr period in these 8 noncomplicating condition-stratified DRGs. Patients with a greater number of complicating conditions (CCs) had higher total hospital costs, a longer hospital length of stay, more procedures per patient, increasing financial risk under DRGs, a larger number of outliers, and a higher mortality than did patients in these same DRGs with a fewer number of CCs. These findings raise the question of the equity of DRG reimbursement at our hospital vis-à-vis the non-CC-stratified pulmonary medicine DRGs. If these findings are generalizable at other teaching hospitals, the current DRG system may provide financial incentives to not treat certain types of pulmonary medicine patients likely to have many CCs, and potentially effect these patient's access and quality of care in the future.

Diagnosis-Related Groups↗
PubMed1988

The role of the neu oncogene product in cell transformation and normal development.

p185neu, the protein product of the neu gene, is a tyrosine kinase receptor with structural similarity to the epidermal growth factor (EGF) receptor. The cognate ligand for the p185neu receptor remains unknown. We have defined: 1) stage and tissue-specific expression patterns of the neu gene product in developing tissues; 2) p185neu phosphorylation and the regulation of p185neu tyrosine kinase activity by EGF. 3) Synergistic interactions of cellular rat p185neu and EGF receptor leading to cell transformation; 4) structural and functional differences of normal and oncogenic p185neu. These observations explain some features of how p185neu is involved in normal development and neoplastic transformation.

Animals↗
PubMed1988

Cytokines as mediators of graft-versus-host disease.

Cytokines are proteins produced mainly by lymphocytes in response to an antigenic stimulus. Originally identified and named on the basis of their biological activity, they are now called interleukins; together with the interferons, colony-stimulating factors and tumour necrosis factor/cachectin (TNF) they form a complex and overlapping network of communication between immunocompetent cells. Cytokines play a central role in T cell activation, and interleukin 2 and interferon gamma in particular are involved in the expression of graft-versus-host disease after bone marrow transplantation. Recent studies suggest that TNF is also implicated: the gene encoding TNF is situated close to the MHC gene in both mice and humans, and TNF is able to up-regulate constitutively expressed class II antigen and, with interferon gamma, to induce class II expression in previously normal cells. Bacterial lipopolysaccharide (endotoxin) is a powerful stimulus to TNF, and TNF production may be the mechanism underlying the longstanding observations on the role of the bacterial microflora of the gut in graft-versus-host disease.

Animals↗