Long-term in vitro culture of hamster pancreatic ß-cells and induction of adenocarcinoma by treatment with N-nitrosobis(2-oxopropyl)amine.

OBJECTIVES: Earlier studies indicated that hamster pancreatic ductal adenocarcinoma not only derives from ductal/ductular structures but also from cells within the islet. So far unidentified cells within the islet are responsive to the carcinogenic effect of N-nitrosobis (2-oxopropyl) amine (BOP) forming poorly differentiated ductal adenocarcinoma. However, studies indicated a major role of ß-cells during carcinogenesis. To find out, if ß-cells are the primary target cells of BOP and if they are capable to form ductal adenocarcinoma after malignant transformation, we established a long-term culture of undifferentiated cells deriving from isolated ß-cells and treated them with BOP. METHODS: Langerhans' islets from pancreata of Syrian golden hamsters were isolated and dispersed into single cells by dispase digestion. Cells were labeled with a highly specific ß-cell surface antibody (K14D10) and these K14D10+ cells were extracted from the suspension by paramagnetic Dynabeads. Cells were cultured in vitro and treated with BOP. Untreated cells served as control. RESULTS: K14D10+ cells formed a monolayer and produced insulin over a period of 28 days in culture. However, with time in culture they became undifferentiated with a higher proliferation rate and after about 60 days in culture BOP treated cells showed anchorage independent growth. These cells autotransplanted s.c. formed a well-differentiated ductal adenocarcinoma. CONCLUSIONS: Pancreatic ß-cells are the primary target of BOP without necessarily being embedded in the compound of the Langerhans' islet. With time in culture, they give rise to undifferentiated cells and after malignant transformation they are able to form ductal adenocarcinoma.

Functional outcome after restorative proctocolectomy in pigs: comparing a novel transverse ileal pouch to the J-pouch and straight ileoanal anastomosis.

BACKGROUND: Restorative proctocolectomy followed by an ileoanal J-pouch procedure is the therapy of choice for patients with familial adenomatous polyposis and ulcerative colitis. After low anterior rectal resection, the authors have reported on a novel, less complex pouch configuration, a transverse coloplasty pouch. The aim of the present work was to apply this new design to the ileal pouch construction, to evaluate feasibility, and to measure functional results in comparison with the J-pouch and the straight ileoanal anastomosis using the pig as an animal model. METHODS: Twenty-three pigs underwent restorative proctocolectomy followed by reconstruction with straight ileoanal anastomosis (IAA; n = 5), J-pouch (n = 7), and a transverse ileal pouch (TIP; n = 11). Pigs were followed for 6 days postoperatively. Peristaltic function was assessed by manometry proximal to the pouch, in the reservoir, and at the level of the ileoanal anastomosis. Functional outcome was monitored by semiquantitative assessment of the general condition of the animals, postoperative feeding habits, and stool frequency and consistency. A Fourier analysis was performed in order to compare peristalsis in the ileal reservoirs. The reservoir volume was measured in situ by triple contrast computed tomography scan with 3D reconstruction. RESULTS: Seventeen animals survived for 1 week. There was no difference in the general condition or the feeding habits of the groups. A significant number of pigs with the TIP pouch (7/10) had semisolid or formed stools as opposed to liquid stools after J-pouch (6/6) and IAA (4/5; p = 0.01). TIP animals had a lower stool frequency (3.2 +/- 1.14 per day) on day 6 after the operation than pigs with J-pouch, 5.33 +/- 1,03, and IAA, 4.6 +/- 1.82 (p = 0.0036). The in situ volume of the pouches did not differ significantly. The Fourier analysis demonstrated a disruption of peristalsis by the J-pouch and the TIP reconstruction but not after IAA. CONCLUSION: The function of ileoanal reservoirs after proctocolectomy may result from the disruption of properistaltic waves after pouch formation. The mechanism of peristalsis disruption is independent of the in situ volume of the pouch.

Donor oocyte cytoplasmic transfer did not enhance implantation of embryos of women with poor ovarian reserve.

PURPOSE: To determine whether donor oocyte cytoplasm transferred into the oocytes of women < or = 40 years or with diminished ovarian reserve would enhance embryo quality, implantation, or pregnancy rates. METHODS: Study subjects included women > or = 40 years (15) or with abnormal FSH levels (3). Healthy volunteers (18) produced oocytes for cryopreservation. Donor oocytes were thawed and cytoplasm from surviving oocytes was injected with a single sperm into the cytoplasm of recipient oocytes. Outcome measures included embryo quality scores, implantation, and pregnancy rates. RESULTS: Eighteen donors produced 213 oocytes for cryopreservation and 39/171 (22.8%) survived thawing. Eighteen recipients initiated 25 IVF cycles with embryo transfer in 20 cycles after cytoplasmic transfer (CT). Four cycles resulted in three biochemical losses and one aneuploid clinical loss. Embryo quality did not improve with CT compared to pre-CT IVF cycles in six recipients. CONCLUSIONS: CT with cryopreserved donor oocyte cytoplasm did not enhance success in women with advanced reproductive age or low ovarian reserve.

The number of embryos available for transfer predicts successful pregnancy outcome in women over 39 years with normal ovarian hormonal reserve testing.

PURPOSE: The purpose was to determine whether the number of embryos available for transfer following IVF in women over age 39 predicted a successful pregnancy outcome. METHODS: Retrospective analysis of 455 consecutive IVF cycles in women > or = 40 years of age. RESULTS: Few cycles were canceled (29/455, 6.4%) or produced no embryos (5/455, 1.1%). Women 40-43 years of age with normal ovarian reserve had a significantly greater delivery rate when > or = 4 embryos were available for transfer than when < 4 embryos were available (17.8% versus 2.4%, P = 0.002). Subsequent IVF cycles, from women with normal FSH whose first cycle produced < 4 embryos, produced delivery rates of 13.0% when > or = 4 embryos were available. Women with abnormal ovarian reserve or age > or = 44 years had very low delivery rates (1.2% and 1.4% respectively). CONCLUSIONS: The number of embryos available for transfer significantly predicts delivery from IVF-ET among reproductively older women. Many women age 40-43 with normal ovarian reserve can achieve pregnancy through IVF.

Pregnancy rates in sequential in vitro fertilization cycles by oocyte donors(1).

OBJECTIVE: To evaluate the clinical outcome of in vitro fertilization (IVF) treatment cycles from individual oocyte donors who underwent multiple sequential donations. METHODS: We reviewed clinical outcome data from sequential anonymous oocyte donation cycles using donors who underwent multiple IVF stimulations. Donors were grouped by the interval between cycles and the cycle number (rank). The primary outcome measure was delivery rate by individual donor per retrieval from the combined derivative fresh and frozen embryo transfers. RESULTS: Duration and amount of gonadotropin therapy and the fertilization rates did not correlate significantly with the interval between cycles or cycle rank. Cumulative delivered pregnancy rates for cycles 1-6 were 51.5%, 54.6%, 50.5%, 51.5%, 51.1%, and 57.6%, respectively. Delivered pregnancy rates did not vary by interval between cycles. CONCLUSION: Young healthy presumed or proven fertile women can reliably donate oocytes for at least six cycles with the expectation of consistently high pregnancy rates.

Validity and cost-effectiveness of antisperm antibody testing before in vitro fertilization.

OBJECTIVE: To determine the usefulness of and cost-effectiveness of antisperm antibody testing in the prediction of poor fertilization rates in couples undergoing IVF. DESIGN: Retrospective cohort study. SETTING: A hospital-based reproductive endocrinology and infertility practice. PATIENT(S): Male partners of 251 couples undergoing IVF between 1992 and 1997. MAIN OUTCOME MEASURE(S): Fertilization rates in couples undergoing conventional IVF. RESULT(S): One hundred nineteen couples were evaluated for antisperm antibodies; fertilization rates were similar in those couples whose husbands were and were not tested (64% versus 68%). Antisperm antibodies were detected in 16 men. Four (25%) of the 16 couples whose husbands had antisperm antibodies fertilized < or = 50% of oocytes, compared with 31 (30%) of the 103 couples whose husbands did not have these antibodies. Overall, 21 couples (8.4%) experienced complete fertilization failure. In a program that included antisperm antibody testing for selected couples and intracytoplasmic sperm injection (ICSI) for those who tested positive, it would cost $11,735 to prevent a fertilization failure (assuming ICSI were 100% effective), whereas it would cost $9,250 to perform ICSI in a second IVF cycle for those who initially failed. CONCLUSION(S): In this practice setting, antisperm antibody testing has low sensitivity in predicting low or no fertilization and does not appear to be cost-effective when selectively ordered as part of an IVF workup.

Single-dose pharmacokinetics of sublingual versus oral administration of micronized 17 beta-estradiol.

OBJECTIVE: To investigate the pharmacokinetic profiles of different doses of micronized 17 beta-estradiol administered by oral or sublingual routes. METHODS: Single doses of micronized 17 beta-estradiol were administered orally (1 mg, 0.5 mg) or sublingually (1 mg, 0.5 mg, 0.25 mg) to six postmenopausal women in a randomized clinical trial. We calculated pharmacokinetic parameters for estradiol (E2) and estrone (E1) of maximum serum concentration, time to maximum serum concentration, terminal half-life, area under the concentration curve, and oral clearance. Serum levels of E1 sulfate also were compared at 4, 12, and 24 hours after dosing. RESULTS: Sublingual administration resulted in rapid absorption with significantly higher E2 levels than did comparable oral dosing. Estrone levels did not vary with route of administration but correlated with the dosage administered. Estrone sulfate levels correlated with the dosage administered and also tended to be higher with sublingual administration. Sublingual administration resulted in a significantly lower E1 to E2 ratio during the 24 hours than did oral administration. CONCLUSION: Sublingual administration of micronized 17 beta-estradiol results in a rapid, burst-like absorption into the systemic circulation, yielding high E2 levels that fall rapidly over the first 6 hours.

Use of a gonadotropin-releasing hormone agonist in the evaluation of postmenopausal virilization due to ovarian hyperthecosis. A case report.

BACKGROUND: Hyperthecosis in a postmenopausal woman is a very rare cause of virilization, and only five cases have been reported previously. CASE: A woman presented with a nine-year history of increasing hirsutism and a mild virilization beginning in the perimenopausal period. Initial androgen metabolite concentrations suggested attenuated late-onset adrenal hyperplasia, but a trial of dexamethasone treatment was ineffective. Subsequent use of leuprolide acetate resulted in a biochemical and clinical improvement in the signs and symptoms. CONCLUSION: This case is unique because gonadotropin-releasing hormone agonist administration was utilized as both a diagnostic and therapeutic modality.

Dehydroepiandrosterone antagonizes the suppressive effects of dexamethasone on lymphocyte proliferation.

Administration of dehydroepiandrosterone (DHEA) appears to have physiological effects opposing those of glucocorticoids in several animal models. Recently, immunomodulatory effects of treatment with DHEA have been described. This paper reports the effects of DHEA treatment on splenocyte blastogenic responses as well as thymic and spleen weights in C3H/HeN mice. Pretreatment of mice with sc DHEA (60 mg/kg.day) for 3 days in vivo antagonized the profound suppression of in vitro blastogenic responses seen in T- and B-lymphocytes after a single injection of dexamethasone (DEX; 60 mg/kg). Pretreatment with DHEA also significantly reduced dexamethasone-induced thymic and splenic atrophy. Splenic lymphocytes from DHEA-treated mice were markedly more resistant to in in vitro suppression of blastogenesis by DEX at 10(-6)-10(-8) M compared to lymphocytes from control mice. However, DHEA added to lymphocyte cultures in vitro over a concentration range from 10(-7)-10(-8) M failed to protect against suppression of mitogenic responses caused by addition of DEX to cultures. In summary, DHEA given in vivo antagonizes the suppressive actions of DEX on lymphoid target tissues in mice.

The effect of intraperitoneal progesterone on postoperative adhesion formation in rabbits.

The immunosuppressive and anti-inflammatory properties of progesterone (P) have been established. The authors investigated whether the intraperitoneal instillation of P would lessen postoperative adhesion formation in New Zealand white rabbits undergoing pelvic surgical procedures. In phase I, severe, peritoneal lesions were made in the right uterine horn (n = 48). Animals were randomized to receive equal volumes of either (1) Ringer's lactate (RL); (2) 32% dextran 70 (HY; Hyskon Division, Pharmacia, Piscataway, NJ); (3) 500 mg P in oil (PO); or (4) 500 mg aqueous P (PA) at initial laparotomy. In phase II, the distal right uterine horn, including the mesosalpinx, was excised and microsurgical anastomosis was accomplished (n = 45). Aqueous P was not used in phase II; otherwise, the same agents were tested. Six weeks later, the severity of the adhesions formed was graded. The mean adhesion scores for the RL and HY groups were low for the right side in both phases and did not differ (P greater than 0.05). In contrast, higher scores were observed in all the P groups, regardless of the P preparation used or the surgical procedure performed (P less than 0.05).