Biomedical subjects

Andreas Mueller

Publications and source records attributed to Andreas Mueller.

22 records · Page 2Linked to original sources

PubMedDate not supplied

The Hohl instrument for optimizing total laparoscopic hysterectomy procedures.

STUDY OBJECTIVE: To evaluate the feasibility of total laparoscopic hysterectomy (TLH) using the Hohl instrument in an initial cohort of patients. DESIGN: Retrospective cohort analysis (Canadian Task Force classification II-3). SETTING: Department of Obstetrics and Gynecology, Erlangen University Hospital, Erlangen, Germany. PATIENTS: Forty-four women underwent the new TLH procedure using the Hohl instrument from May 2004 through January 2005. The laparoscopic approach was used when the patient had undergone more than one previous pelvic abdominal operation and/or had a reduced vaginal capacity. The indications for hysterectomy were symptomatic leiomyoma in 25 patients and hypermenorrhea in 19 patients. INTERVENTION: Total laparoscopic hysterectomy using the Hohl instrument. MEASUREMENTS AND MAIN RESULTS: No ureteral or bladder injury occurred in any of the patients. The complication rate during surgery and in the postoperative period was zero. The mean loss of hemoglobin was 1.68+/-0.96 g/dL, the mean operating time was 108+/-21 minutes, and the mean uterine weight was 302+/-121 g. CONCLUSION: Total laparoscopic hysterectomy using the Hohl instrument simplifies the surgical procedure. The reported technique is an option comparable with laparoscopic-assisted vaginal hysterectomy and may be effective in preventing minor and major complications during TLH.

Adult↗

PubMedDate not supplied

Development of sex cord stromal tumors after heterotopic transplantation of cryopreserved ovarian tissue in rats.

Chemoradiotherapy has substantially improved life expectancy in young women with cancer, but these treatments often cause infertility. One method of preserving fertility is to cryopreserve ovarian tissue, with subsequent autotransplantation of the tissue after successful anticancer therapy. This study examined the long-term effect of heterotopic transplantation of cryopreserved ovarian tissue on the histology. Ovarian tissue from rats was cryopreserved using a slow-freezing protocol. After thawing, the tissue pieces were transplanted under the splenic capsule in 14 rats of the same inbred strain and remained there for 210 or 300 days. Sex cord stromal tumors, consisting mainly of granulosa cells, were found in all of the rats. Although the hormonal situation in rats cannot be directly compared to that in humans, the development of sex cord stromal tumors in this animal model may be worth considering when cryopreserved ovarian tissue is transplanted heterotopically in fertility-preserving programs for cancer patients.

Animals↗

PubMedDate not supplied

The role of albumin in the calculation of free and bioavailable testosterone in women with hyperandrogenemia.

BACKGROUND: The aim of this study was to assess the role of albumin in the calculation of free testosterone (cFT) and bioavailable testosterone (cBT). PATIENTS AND METHODS: Ninety-two healthy women, who presented at our fertility center for evaluation of possible hyperandrogenemia, were included in the study. Total blood testosterone (TT), free testosterone (FT) and sex hormone-binding globulin (SHBG) were measured using commercially available enzyme immunoassays in one serum sample. cFT and cBT were then calculated, taking into account the individual albumin concentration, but without taking account of each individual albumin serum concentration. RESULTS: No differences were observed in the calculated values for FT and BT, with or without taking into account the individual albumin concentration. A correlation between the two was demonstrated. CONCLUSION: For clinical routine work, it is not necessary to estimate the individual albumin concentration in hyperandrogenic women in order to calculate the FT and BT concentrations from TT and SHBG serum concentrations, when the albumin concentration is in the physiological range of 40-50 g/L.

Adult↗

PubMedDate not supplied

Xenotransplantation of human ovarian tissue pieces in gonadotropin-stimulated SCID mice: the effect of ovariectomy.

The number of follicles were compared in different developmental stages after the cryopreservation of human ovarian tissue by open freezing system followed by xenotransplantation into severe combined immunodeficient (SCID)-mice under stimulation, with and without ovariectomy. Ovarian tissue, cryopreserved for fertility preservation was partly examined by LIVE/DEAD viability staining or was transplanted in the neck muscle of 32 SCID-mice. The development of follicles, estradiol production, vaginal cytology and uterus weight was assessed after 15 weeks under gonadotropin stimulation, with or without ovariectomy. Viable follicles were detected in all frozen/thawed specimens using the LIVE/DEAD assay. Ovariectomy caused a significant improvement of survival of follicles in the preantral and antral stages in the gonadotropin-stimulated animals (p < 0.001), whereas there was no significant effect on the primordial and primary follicle counts. In the non-ovariectomised group, only isolated primordial and primary follicles could be detected. The total follicle amount was significantly higher in the ovariectomised group (n=17, 9.2 +/- 7.8, mean +/-SD) than in the non-ovariectomized group (n=15, 0.3 +/- 1.0). This study demonstrates that ovariectomy of stimulated recipient SCID-mice is essential for the development of follicles after xenotransplantation of cryopreserved human ovarian grafts.

Animals↗