Biomedical subjects

G S Oshinsky

Publications and source records attributed to G S Oshinsky.

5 recordsLinked to original sources

PubMed1996

New technique in managing ureteropelvic junction obstruction: percutaneous endoscopic pyeloplasty.

Endopyelotomy is currently advocated for management of the obstructed ureteropelvic junction (UPJ). Healing of the stented UPJ occurs by secondary intention. Regardless of the method employed, success rates approach 85%. In order to increase the rate of success, we have devised a method of performing endopyelotomy in conjunction with endoscopic suturing of the incised UPJ. Two methods were developed to allow for the placement of a single absorbable monofilament suture. In the first method, endopyelotomy is carried out in the standard antegrade manner, and endoscopic suturing is performed with the use of a second retroperitoneal access sheath at the UPJ. In the second method, endoscopic placement of the suture is carried out through the standard renal access sheath, with suturing performed via the nephroscope. We have performed endoscopic pyeloplasty in eight patients. With a mean follow-up of 12 months, the procedure was successful in seven of these patients. Endoscopic suturing of the UPJ is technically demanding, but once sufficient expertise is gained, it may be utilized for immediate tissue coaptation, possibly decreasing urinary extravasation and, it is hoped, maximizing the caliber of the UPJ.

Adult↗

PubMed1995

A model of bladder tumor xenografts in the nude rat.

PURPOSE: An in vivo tumor model for the study of human urothelial carcinoma is desirable. Orthotopic xenografts are useful in order to better approximate human tumor cell behavior in situ. A prior model has been described in the nude mouse. However, its small bladder size limits both histologic characterization and the application of intravesical therapeutics. In the absence of preirradiation, orthotopic xenografts of human transitional cell carcinoma in the nude rat has not been previously reported. MATERIALS AND METHODS: Nude rats 2 to 4 weeks of age were inoculated with 1-5 x 10(6) cells of RT4 (well differentiated papillary human bladder tumor cell line). Inoculation was performed via open cystotomy. Techniques of mucosal injury including acid treatment and cautery were explored in an effort to optimize tumor implantation and growth. Animals were sacrificed at varying intervals and histologic assessment was performed. RESULTS: The overall rate of tumor implantation and growth was 93.4% (57 of 61). Tumors reliably grew within the muscularis and mucosal growth was seen as well. Intramuscular tumor growth was less differentiated and had a higher fraction of mitotic cells than mucosal tumor. Tumor growth was consistently seen as early as 2 weeks after inoculation which facilitates experimental trials. Distant metastasis was not observed. Mucosal injury did not increase the rate of tumor implantation. CONCLUSION: This model is highly reproducible and will prove useful in the further study of bladder cancer progression as well as in the development of therapeutic modalities for both superficial and muscle invasive bladder carcinoma.

Animals↗

PubMed1993

Varicocele-related infertility is not associated with increased sperm-bound antibody.

Immunological factors have been implicated as a cause of unexplained infertility. Previous studies have demonstrated increased levels of sperm-bound antibody in infertile men with varicoceles and have postulated their role in varicocele-related infertility. However, these studies were performed using an enzyme-linked immunosorbent assay. We evaluated retrospectively 111 male patients referred for infertility using a direct immunobead assay. Of the patients 29 had grade II or III varicoceles (that is palpable or easily visualized) and 82 were without varicocele. Four patients who had undergone vasovasostomy were included as controls for the assay. A direct immunobead assay was performed for isotype IgG and IgA sperm-bound antibody using a standard protocol. A computerized semen analysis was also performed. Greater than 20% binding, excluding tail tip activity, was considered significant. Of 29 patients with and 82 without a varicocele significant binding was identified in 5 (17%) and 9 (11%), respectively. Chi-square statistical analysis did not reveal this difference to be significant (p < 0.05). All 4 vasovasostomy patients demonstrated significant binding. We conclude from this study that infertile men with varicoceles do not demonstrate significantly increased levels of sperm-bound antibody compared to infertile controls and, therefore, sperm-bound antibody does not appear to have a significant role in varicocele-related infertility.

Antibodies↗

PubMed1993

Laparoscopic entry and exit.

Minimal access surgery has emerged as an acceptable means of performing therapeutic and diagnostic surgical procedures. Although the gynecologist has utilized the laparoscope for several decades, only recently has laparoscopic surgery gained increased acceptance in the general surgical and urologic community. The number of laparoscopic procedures being performed routinely is now extensive and growing rapidly. It appears that the critical step in performing laparoscopic surgery is the establishment of pneumoperitoneum and the placement of the trocars. This initial part of the procedure when performed properly ensures safe and reliable access allowing the procedure to commence. Difficulties with this part of the procedure may preclude the operative procedure and more importantly may result in potentially severe injuries. Therefore a detailed discussion of the method of performing laparoscopic entry and exit will provide the urologist with the essentials to perform safe and successful laparoscopy.

Equipment Design↗

PubMed1992

Laparoscopic needles and trocars: an overview of designs and complications.

Although the gynecologist has utilized the laparoscope both diagnostically and therapeutically for several decades, laparoscopic surgery has only recently gained great acceptance in the general surgical and urologic community. However, the enthusiasm for this new technology for minimally invasive surgery must be dampened by the small incidence of complications, most of which occur during the creation of the initial pneumoperitoneum and, in particular, during the insertion of the Veress needle and the principal trocar. The purpose of this paper is to review needle and trocar designs, to describe the complications of their use, and to identify factors that may contribute to injury and those that will minimize the risk.

Catheterization↗