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R S Schenken

Publications and source records attributed to R S Schenken.

At least 19 recordsLinked to original sources
PubMed2001

Short-term culture of peritoneum explants confirms attachment of endometrium to intact peritoneal mesothelium.

OBJECTIVE: To evaluate the initial adhesion of endometrium to the peritoneum. DESIGN: Descriptive study using light and confocal laser-scanning microscopy, immunohistochemistry, and transmission electron microscopy. SETTING: University-based laboratory. PATIENT(S): Women without endometriosis undergoing surgery for benign conditions. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Explants of peritoneum (n = 20), prepared from four patients, were cultured for 1 hour with mechanically dispersed proliferative or secretory endometrium. Peritoneum was cultured with endometrium from the same patient. Specimens were fixed and serially sectioned for hematoxylin and eosin stain, immunohistochemistry using an anti-cytokeratin monoclonal antibody, and transmission electron microscopy. RESULT(S): In 17 of 20 explants, endometrium was adherent to intact mesothelium. There was no evidence of transmesothelial invasion at any sites of attachment. Although in most cases endometrium was adherent to mesothelium via endometrial stroma, there were many sites of endometrial epithelium-mesothelium attachment. Confocal laser scanning microscopy demonstrated an intact monolayer of cytokeratin-positive cells below the sites of endometrial implantation. Transmission electron microscopy demonstrated intact, viable, mesothelial cells below sites of attachment. CONCLUSION(S): This study demonstrates that endometrium rapidly adheres to intact peritoneal mesothelium. In addition, this study demonstrates that endometrial epithelial cells, as well as stroma, can attach to mesothelium. Further studies are needed that characterize the mechanism of endometrial-mesothelial cell adhesion.

Cell Adhesion↗
PubMed2001

Mesothelial cell-associated hyaluronic acid promotes adhesion of endometrial cells to mesothelium.

OBJECTIVE: To evaluate the role of hyaluronic acid in the attachment of endometrial cells to mesothelium. DESIGN: In vitro study of adhesion of endometrial stromal and epithelial cells to mesothelial cells. SETTING: University medical center. PATIENT(S): Reproductive-age women without endometriosis undergoing surgery for benign conditions. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The effect of hyaluronidase treatment of mesothelial cells or endometrial cells on adhesion of (51)Cr labeled endometrial stromal and epithelial cells to monolayers of mesothelium was evaluated. The expression of CD44, the hyaluronate receptor, was evaluated by western blot. RESULT(S): Hyaluronidase pretreatment of mesothelial cells decreased the binding of endometrial stromal and epithelial cells to mesothelium by 39% (P< .02) and 31% (P< .03), respectively. There was no effect on endometrial cell binding to mesothelial cells or to collagen IV when the endometrial cells were pretreated with hyaluronidase. CD44 expression by endometrial stromal and epithelial cells was demonstrated by western blot. CONCLUSIONS: This study demonstrates that mesothelial cell-associated hyaluronic acid is involved in attachment of endometrial stromal and endometrial epithelial cells to the mesothelium. We hypothesize that binding of hyaluronic acid by endometrial cells is involved in the pathogenesis of the early endometriotic lesion.

Cell Adhesion↗
PubMed2001

Effect of acute administration of cocaine on pituitary gonadotrophin secretion in female rats.

The aim of this study was to characterize the acute effects of cocaine administration on pituitary gonadotrophin secretion in adult female rats. Ovariectomized, oestradiol-treated rats were infused i.v. with 0.1 ml normal saline or 2 mg cocaine hydrochloride kg(-1). Blood samples were collected immediately before cocaine infusion and at 3, 10, 30 and 60 min after cocaine infusion. Circulating LH concentrations were increased by 10 min after cocaine administration (P < 0.05 versus saline-treated controls) and decreased thereafter. Serum FSH concentrations were not significantly different from those of saline-infused controls at any time. In a second experiment, oestradiol-treated, ovariectomized rats were infused i.v. with: saline only, 2 mg cocaine hydrochloride kg(-1) in saline, 200 ng synthetic GnRH in 100 microl PBS or 200 ng synthetic GnRH plus 2 mg cocaine hydrochloride kg(-1) in PBS. Blood samples were collected immediately before drug infusions and 20 min later. Cocaine had no effect on either GnRH-stimulated LH or FSH secretion. In a third experiment, pituitary cells were obtained from oestradiol-treated, ovariectomized rats. The cell cultures were exposed to 25 ng cocaine hydrochloride ml(-1), 10(-10)-10(-7) mol GnRH (-1) with and without 25 ng cocaine hydrochloride ml(-1), or vehicle only. Medium was collected before and after exposure to GnRH to determine concentrations of secreted LH and FSH. Similar to the results of the second study, cocaine had no effect on GnRH-stimulated LH or FSH secretion from pituitary cells in vitro. On the basis of these results it is suggested that acutely administered cocaine stimulates release of hypothalamic GnRH, which, in turn, stimulates pituitary gonadotrophin secretion. Acute administration of cocaine does not appear to affect pituitary gonadotrophin secretion directly.

Analysis of Variance↗
PubMed2000

Expression of the alpha2beta1 and alpha3beta1 integrins at the surface of mesothelial cells: a potential attachment site of endometrial cells.

OBJECTIVE: To localize alpha2beta1 and alpha3beta1 integrins in the cell membrane of peritoneal mesothelium in vivo and in vitro. DESIGN: Descriptive study using confocal and two-photon laser-scanning microscopy. SETTING: University-based laboratory. PATIENT(S): Women without endometriosis undergoing surgery for benign conditions. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Peritoneal biopsies (n = 9) and mesothelial monolayer cultures (n = 4) were incubated with antibodies to the alpha2 and alpha3 subunits and to the intact alpha2beta1 and alpha3beta1 integrins. Specimens were examined with laser-scanning microscopy. RESULT(S): The alpha2 and alpha3 subunits and the intact alpha2beta1 and alpha3beta1 integrins were identified at the base of the mesothelial cells (i.e., toward the basement membrane). There was also expression of the alpha2 and alpha3 subunits and the intact alpha2beta1 and alpha3beta1 integrins at the cell surface (i.e., toward the peritoneal cavity). CONCLUSION(S): The resolution of the confocal and two-photon laser-scanning microscope enabled localization of integrins in mesothelial cells. The presence of alpha2beta1 (collagen-laminin receptor) and alpha3beta1 integrins (collagen-laminin-fibronectin receptor) at the base of mesothelial cells suggests a role for these molecules in adhesion to the basement membrane. The presence of these molecules at the cell surface suggests a potential locus for cell adhesion in such processes as endometriosis and cancer metastasis.

Adult↗
PubMed1999

Concentration-dependent effects of muscimol to enhance pulsatile GnRH release from GT1-7 neurons in vitro.

Immortalized GT1-7 neurons were used to characterize the effect of muscimol, a GABAA receptor agonist, to enhance pulsatile gonadotropin-releasing hormone (GnRH) release. GT1-7 neurons were grown on Cytodex-3 beads and placed in special superfusion microchambers. The cells were superfused at a rate of 6.2 ml x h-1 with Media 199 (pH 7.35) using a commercially available perfusion system. After a pre-muscimol period of 120 min, the cells were exposed for 5 min to 0.35, 1, 5 or 10 microM muscimol or 5 microM muscimol+20 microM of the GABAA receptor antagonist, bicuculline. Following removal of the muscimol (and bicuculline, in the case of the latter experiment), the superfusion was continued for another 115 min. Sample fractions were collected at 5 min intervals throughout the perfusion. Basal GnRH release from the GT1-7 neurons was pulsatile with an average interpulse interval of 45.4+/-0.5 min and an average pulse amplitude of 191.5+/-22.6 pg x min x ml-1. Our results also demonstrated that the GABAA receptor agonist, muscimol, enhances pulsatile GnRH release from GT1-7 neurons in culture. The response to muscimol was saturable and concentration-dependent with an EC50 of 0.47 microM. The effects of 5 microM muscimol to increase GnRH pulsatility were blocked by co-exposure to the GABAA receptor antagonist, bicuculline. The average GnRH interpulse intervals were 41.7+/-1.8 min, 32.5+/-2.9 min, 30.6+/-0.7 min and 25.5+/-0.4 min in the period following exposure to 0.35, 1, 5 and 10 microM of muscimol, respectively (post-muscimol period). GnRH pulse amplitude (mean-area for each pulse) was increased during exposure to muscimol but not during the pre- or post-muscimol periods. The GABAA receptor antagonist, bicuculline, itself had no effect on pulsatile GnRH release. These results are consistent with previously published reports suggesting that activation of the GABAA receptor stimulates hypothalamic GnRH release in embryonic and neonatal animals.

Animals↗
PubMed1999

Whole explants of peritoneum and endometrium: a novel model of the early endometriosis lesion.

OBJECTIVE: To determine whether whole fragments of endometrium can adhere to peritoneum with intact mesothelium. DESIGN: Tissue culture and immunohistochemical study. SETTING: University medical center. PATIENT(S): Reproductive-age women undergoing surgery for benign conditions. INTERVENTION(S): Explants of human peritoneum from the anterior abdominal wall and the posterior surface of the uterus were cultured with whole fragments of mechanically dispersed endometrium. MAIN OUTCOME MEASURE(S): Adhesion of endometrial fragments to the surface of the peritoneum was evaluated. Adherent endometrium was identified with the use of the dissecting microscope and by the performance of serial sections of the peritoneum explants. Immunohistochemical staining of the mesothelium with antibodies to cytokeratin was used to ensure an intact layer of mesothelium beneath the endometrial implants. Transmission electron microscopy also was used to evaluate this adhesion process. RESULT(S): Endometrium was identified attached to the surface of the peritoneum. Most of the implants did not have identifiable mesothelium beneath them, but most had intact mesothelium running up to the point of attachment. Approximately 10% of the endometrial implants had intact mesothelium at the site of attachment. Endometrial stromal cells, and not epithelium, attached to the mesothelium. CONCLUSION(S): Endometrium can attach to the mesothelial surface of the peritoneum. Endometrial stromal cells are involved in this attachment. Invasion through the mesothelium seems to occur rapidly.

Adult↗
PubMed1999

Is there a risk of cytomegalovirus transmission during in vitro fertilization with donated oocytes?

OBJECTIVE: To define the risk of human cytomegalovirus (HCMV) transmission from donated oocytes. DESIGN: Prospective study. SETTING: University IVF program. PATIENT(S): Sixty-seven couples undergoing 72 cycles of IVF-ET. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Serum from both partners (women: n = 71; men: n = 60) was obtained for detection of antibodies to HCMV. Semen before preparation (n = 53), sperm after preparation (Percoll gradient; n = 47), cervical mucus aspirated at the time of oocyte aspiration (n = 70), and uninseminated oocytes and embryos not suitable for cryopreservation (n = 568) were frozen in liquid nitrogen. Polymerase chain reaction was used for detection of HCMV (immediate early 1 gene) in all samples collected. RESULT(S): Serum antibodies to HCMV were found in 62% of the women and 37% of the men tested. Human cytomegalovirus DNA was detected in 25% of the ejaculates and in 19% of the cervical mucus samples. There was no amplification of HCMV DNA from oocytes or embryos. CONCLUSION(S): Because we were unable to amplify HCMV DNA from any of the oocytes or embryos, it seems unlikely that HCMV is transmissible through oocyte or embryo donation.

Antibodies, Viral↗
PubMed1999

Pathophysiology and management of proximal tubal blockage.

OBJECTIVE: To review the physiology, pathology, and treatment of proximal tubal disease. DATA IDENTIFICATION: Relevant reports on the pathophysiology of proximal tubal disease were reviewed. All studies in English of microsurgery and macrosurgery, and of radiographic and hysteroscopic cannulation in women with proximal tubal blockage were identified through MEDLINE searches. STUDY SELECTION: All studies of therapy for proximal blockage that included pregnancy rates were considered. Series of sterilization reversals, series of unilateral or combined procedures, and series in which the location of tubal blockage was not given were excluded from the data analyses. DATA ANALYSIS: Raw data were assessed for homogeneity, then standardized and pooled. Total and ongoing pregnancy rates after microsurgery and macrosurgery, as well as radiographic and hysteroscopic transcervical cannulation, were compared by the chi2 test. Relative risks for total and ongoing pregnancies were calculated for all treatment methods. RESULT(S): This meta-analysis suggests that, overall, microsurgical anastomosis results in higher total and ongoing pregnancy rates than macrosurgery or radiographic tubal cannulation. However, pregnancy rates in selected series of transcervical tubal cannulation are similar to those reported for microsurgery. CONCLUSION(S): Ongoing intrauterine pregnancy rates near 50% can be achieved in patients with proximal blockage of the fallopian tube. Selective salpingography and transcervical cannulation under fluoroscopic guidance are effective at establishing patency in appropriately selected patients and are less invasive and costly than the surgical alternatives.

Anastomosis, Surgical↗
PubMed1999

Survival of cryopreservation and thawing with all blastomeres intact identifies multicell embryos with superior frozen embryo transfer outcome.

OBJECTIVE: To assess the impact of survival of cryopreservation and thawing with all blastomeres intact on the outcome of multicell frozen ET. DESIGN: Retrospective study. SETTING: Academic assisted reproductive technology program. PATIENT(S): One hundred sixteen exclusively multicell frozen ETs in 78 patients. INTERVENTION(S): Frozen ET. MAIN OUTCOME MEASURE(S): Relation of embryonic blastomere survival to the outcome of frozen ET (i.e., pregnancy). RESULT(S): When at least one embryo survived with all blastomeres intact, the total pregnancy rate (biochemical, clinical, or delivered) was 37.7%, the clinical pregnancy rate was 24.6%, and the delivered pregnancy rate was 18.8%. When no embryo survived with all blastomeres intact, the corresponding rates were 10.6%, 8.5%, and 6.4%. The differences in the total pregnancy rate and the clinical pregnancy rate were statistically significant. The delivered pregnancy rates approached statistical significance. CONCLUSION(S): Multicell embryonic survival of cryopreservation and thawing with all blastomeres intact identifies embryos with superior developmental potential.

Adult↗
PubMed1999

Thrombin-stimulated increases in cytosolic Ca2+ level and gonadotropin-releasing hormone release in GT1-7 neurons.

The effects of thrombin on cytosolic calcium levels ([Ca2+]cyt), and on gonadotropin-releasing hormone (GnRH) release, were characterized in cultured GT1-7 neurons. GnRH release from GT1-7 neurons was pulsatile with an average pulse amplitude of 14.3+/-5.8 pg x min x ml(-1) and an average pulse duration of 21.3+/-4.2 min. The [Ca2+]cyt response to 0.005 to 0.2 U/ml thrombin was saturable and concentration dependent (EC50 = 0.0268 U/ml). Ethyleneglycotetraacetic acid (EGTA) chelation of extracellular Ca2+ resulted in an approximately 70% attenuation of thrombin-stimulated increase in [Ca2+]cyt. By use of a special superfusion system, a 5-min exposure to 0.1 U/ml thrombin significantly increased the amplitude (193.2+/-67.8 pg x min x ml(-1); P = 0.001) but not the duration (22.5+/-2.4 min; P = 0.8) of GnRH release. These results suggest that thrombin increases [Ca2+]cyt and GnRH release from GT1-7 neurons via specific membrane-bound receptors.

Animals↗
PubMed1998

Effects of follicular-phase cocaine administration on menstrual and ovarian cyclicity in rhesus monkeys.

OBJECTIVE: The purpose of this study was to evaluate the effects of daily follicular-phase cocaine administration on menstrual cyclicity, gonadotropin and ovarian steroid levels, ovulation rates, and corpus luteum function in cycling rhesus monkeys. STUDY DESIGN: Thirteen normally cycling, drug-naive adult rhesus monkeys were randomized to receive daily intravenous injections of either 4 mg/kg cocaine or an equal volume of saline solution. Treated animals were yoked to pair-fed controls to minimize differences in caloric intake. Daily blood samples were obtained through indwelling catheters for measurement of serum gonadotropin and ovarian steroid levels. Daily vaginal swabs were obtained to determine the onset of menses. Laparoscopy was performed 2 days after the midcycle estrogen peak to check for ovulation. Daily caloric intakes and pretreatment and posttreatment weights were recorded. RESULTS: All six of the control monkeys had laparoscopically confirmed ovulation compared with one of seven in the cocaine-treated group (p < 0.004). Cycle length was normal in five of six controls versus one of seven cocaine-treated monkeys. Estradiol levels were significantly higher in the controls versus the cocaine-treated monkeys (p = 0.01) during the first 14 days of the treatment cycle. There were no differences in basal plasma gonadotropin levels between groups. Luteal-phase lengths and luteal-phase plasma progesterone levels were similar in the controls and the single ovulatory cocaine-treated monkey. There were no significant differences in weight change or caloric intake between the two groups. CONCLUSIONS: Daily follicular-phase cocaine administration disrupts menstrual cyclicity and folliculogenesis independent of weight loss, caloric intake, and basal gonadotropin levels.

Animals↗
PubMed1998

Endometrial biopsy during hormone replacement cycle in donor oocyte recipients before in vitro fertilization-embryo transfer.

OBJECTIVE: To examine the usefulness of a trial cycle of hormone replacement therapy (HRT) and endometrial biopsy before the actual ET cycle in recipients of donated oocytes. DESIGN: Retrospective review. SETTING: Clinical practice at the South Texas Fertility Center, San Antonio, Texas. PATIENT(S): Thirty-six concurrent patients who underwent a trial cycle of HRT with endometrial biopsy before the ET cycle with donated oocytes fertilized in vitro. INTERVENTION(S): Patients > or =40 years of age received 100 mg of i.m. progesterone in oil daily; patients <40 years of age received 50 mg daily. Endometrial biopsies were performed during the late luteal phase of the trial cycle. MAIN OUTCOME MEASURE(S): Histologic dating of the biopsy specimens was correlated with the chronologic date of the biopsy. RESULT(S): Five of 20 patients > or =40 years of age had out-of-phase biopsies. All 16 patients <40 years of age had in-phase biopsies. All out-of-phase biopsies subsequently were corrected with higher doses of progesterone. Pregnancy rates after fresh and frozen ETs were not significantly different between the two age groups. CONCLUSION(S): Patients > or =40 years of age are at risk of having out-of-phase endometrial biopsies while they are receiving standard HRT despite receiving higher doses of progesterone. Trial HRT cycles with endometrial biopsies are recommended.

Adult↗
PubMed1998

Noncommunicating accessory uterine cavity.

OBJECTIVE: To report a case of a noncommunicating accessory uterine cavity. DESIGN: Case report. SETTING: University-affiliated reproductive endocrinology practice. PATIENT(S): A 15-year-old nulligravida with increasing dysmenorrhea. INTERVENTION(S): Pelvic ultrasound, intravenous pyelogram, hysterosalpingogram, laparoscopy, laparotomy, and resection of noncommunicating accessory uterine cavity. MAIN OUTCOME MEASURE(S): Results of imaging studies, surgical examination, and resection of anomaly. RESULT(S): Complete resection of accessory cavity and resolution of dysmenorrhea. CONCLUSION(S): The patient had a müllerian anomaly in which the uterus contained two uterine cavities. One normal uterine cavity with communication to both fallopian tubes was present along with a noncommunicating, accessory uterine cavity.

Adolescent↗
PubMed1998

Modern concepts of endometriosis. Classification and its consequences for therapy.

OBJECTIVE: To review the development of the American Society for Reproductive Medicine (ASRM) classification forms for endometriosis and assess efforts to validate their clinical utility. STUDY DESIGN: The relevant medical literature was reviewed. RESULTS: ASRM has established classification forms for endometriosis in women with infertility and pelvic pain. The utility of these new forms has not been assessed. Studies using earlier versions of the ASRM classification reported that the stage of disease correlates better with pain symptoms than fertility outcome. CONCLUSION: The ASRM classification form for infertility and the form to assist in the management of pelvic pain in women with endometriosis permit clear documentation of the extent and morphologic type of disease. Further studies are needed to refine the classification and enhance its predictive ability.

Endometriosis↗
PubMed1997

Prediction of pregnancy in infertile women based on the American Society for Reproductive Medicine's revised classification of endometriosis.

OBJECTIVE: To estimate the empirical relationship between the revised American Society for Reproductive Medicine's classification of endometriosis and pregnancy rates after treatment. DESIGN: Retrospective analysis. PATIENT(S): Patients seen by four practicing physicians. INTERVENTION(S): Medical and/or surgical therapy for endometriosis. MAIN OUTCOME MEASURE(S): Pregnancy defined as ongoing or delivered. RESULT(S): There were no significant differences in pregnancy rates across stages of endometriosis. There was a slight decline in pregnancy rates among patients with Stage IV endometriosis, but statistical significance was not achieved. CONCLUSION(S): The use of an arbitrary weighted system for assigning scores to individual categories of disease, or for computing a total score, has limited the overall effectiveness of the classification system to predict pregnancy.

Adult↗