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S al-Hassan

Publications and source records attributed to S al-Hassan.

4 recordsLinked to original sources
PubMed1998

Low plasma levels of hCG after 10,000-IU hCG injection do not reduce the number or maturation of oocytes recovered in patients undergoing assisted reproduction.

PURPOSE: Our purpose was to determine whether there is a correlation between human chorionic gonadotropin (hCG) blood levels and oocyte maturation. METHODS: Three samples of blood were obtained at different times from hCG administration as follows: 12 hr, 36 hr, during oocyte recovery, and at 84 hr, when the patient comes for embryo transfer. RESULTS: A total of 5036 oocytes was retrieved from 404 patients prospectively recruited between April 1996 and March 1997. The percentage of metaphase-II oocytes at different blood levels ranged from 84 to 88%. The general trend does not show any significant increase in percentage of metaphase-II oocytes in association with an increasing serum hCG concentration. CONCLUSIONS: The results of this study suggest that at 12, 36, and 84 hr after hCG administration, levels as low as 50, 45, and 9 IU/L of hCG, respectively, are equally potent as higher levels at initiating maximal oocyte maturity.

Adult↗
PubMed1996

Predicting empty follicle syndrome.

OBJECTIVE: To determine a simple predictive test for empty follicle syndrome before oocyte retrieval. DESIGN: Retrospective correlation analysis. SETTING: Patients attending Nottingham University Research and Treatment Unit, a tertiary, university-based assisted reproductive technologies (ART) program between April 1, 1994 and March 31, 1995. PATIENT(S): Six women in whom no oocytes were retrieved after superovulation for ART (empty follicle syndrome) were compared with 11 women with successful oocyte retrieval. INTERVENTION(S): Subcutaneous buserelin acetate plus IM hMG and hCG were used for superovulation. Oocyte retrieval was transvaginal and ultrasound guided. MAIN OUTCOME MEASURE(S): Ultrasound measurement of follicular growth and serum E2 levels during superovulation. Serum beta-hCG levels before and 36 hours after hCG administration IM. Number of oocytes retrieved. RESULT(S): Before hCG administration, beta-hCG was not detectable in the serum. The serum beta-hCG 36 hours after hCG was 209 +/- 16.7 mIU/mL (conversion factor to SI units, 1.0; mean +/- SEM, range 106 to 290 mIU/mL) in women with successful oocyte retrieval and 4 +/- 1.8 mIU/mL (range 0 to 9 mIU/mL) in empty follicle syndrome. This difference was significant. CONCLUSION(S): Empty follicle syndrome is associated with very low bioavailability of beta-hCG and can be predicted by measuring serum beta-hCG level 36 hours after IM hCG administration.

Adult↗
PubMed1989

Model for simulating the effects of management practices on pesticide concentrations in groundwater.

This manuscript describes the RUSTIC model and presents the results of an example application. RUSTIC links three subordinate models in order to predict pesticide fate and transport through the crop root zone, unsaturated zone, and saturated zone to drinking water wells: PRZM, VADOFT, and SAFTMOD. PRZM is a one-dimensional finite-difference model which accounts for pesticide fate and transport in the crop root zone. This release of PRZM incorporates several features in addition to those simulated in the original PRZM code: specifically, soil temperature simulation, volatilization and vapor phase transport in soils, irrigation simulation and a method of characteristics (MOC) algorithm to eliminate numerical dispersion. PRZM is now capable of simulating fate and transport of the parent compound and up to two daughter species. VADOFT is a one-dimensional finite-element code which solves the Richard's equation for flows in the unsaturated zone. The user may make use of constitutive relationships between pressure, water content, and hydraulic conductivity to solve the flow equations. VADOFT may also simulate the fate and transport of two parent and two daughter products. SAFTMOD is a two-dimensional finite-element model which simulates saturated solute flow and transport in either an X-Y or X-Z configuration. The codes are linked together with the aid of a flexible execution supervisor which allows the user to build models which are tailored to site-specific situations. In order to perform exposure assessments, the code is equipped with a Monte Carlo pre- and post-processor. The application of the model is to a potato field on Long Island, New York. The results indicate that RUSTIC is capable of realistically matching data observed in downgradient monitoring wells following 3 years of aldicarb application.

Aldicarb↗