Collin Osuamkpe

Insulin-like growth factor I and II binding in human myometrium and leiomyomas

OBJECTIVES The purpose of this study is to determine if the human myometrium has receptors for insulin-like growth factors I and II and whether the concentration of these receptors is increased in leiomyomas. STUDY DESIGN Specific binding of iodine 125-labeled insulin-like growth factor I and II was examined in the membrane preparations of myometrium and leiomyomas obtained from 10 women with uterine leiomyomas. RESULTS Binding studies indicate presence of specific binding sites for both insulin-like growth factors I and II in the myometrium and leiomyoma. The concentration of binding sites for insulin-like growth factor I, but not for insulin-like growth factor II, was significantly (p less than 0.01) higher in leiomyomas than in the myometrium. The dissociation constants for insulin-like growth factors I and II receptors in both myometrium and leiomyoma were similar. CONCLUSION insulin-like growth factor I, but not insulin-like growth factor II, receptors are increased in leiomyomas compared with those in myometrium, indicating that insulin-like growth factor I may play a role in the generation and/or growth of this tumor.

Spontaneously developed tail swellings (SDTS) influence the accuracy of the hypo-osmotic swelling test (HOS-test) in determining membrane integrity and viability of human spermatozoa

PurposeTo investigate the prevalence of spontaneously developed tail swellings (SDTS) in human sperm samples that are commonly encountered in the laboratory, and their influence on the hypo-osmotic swelling test (HOS-test).MethodsEjaculated, epididymal, and testicular sperm were evaluated for SDTS. Further, HOS-test scores were compared with those of vital stains using column washed sperm maintained in the laboratory.ResultsSDTS, at <10%, was present in all types of sperm samples. The highest and lowest occurrences of SDTS were found in cryopreserved sperm, and column-washed sperm respectively. SDTS can inflate the HOS-test score, and so lower the accuracy of the HOS-test. However, the HOS-test efficiency can be improved by assessing SDTS in the sample.ConclusionHOS-test and vital stain cannot be used interchangeably in all circumstances for sperm viability determination. The accuracy of the HOS-test can be enhanced by incorporating SDTS as a correction factor.

Sole Use of Sucrose in Human Sperm Cryopreservation

Glycerol alone or in combination with other additives is one of the most widely used and successful cryoprotectants for human sperm. The glycerol method requires rigorous post thaw sample washing for use in ART and this may lead to low sperm yield from oligospermic samples. In this study the feasibility of the use of sucrose in sperm cryopreservation was explored. Sucrose as cryoprotectant was combined with direct plunging of sample into liquid nitrogen (vitrification) as a freezing method. Sucrose treated sperm from normozoospermic and severly oligozoospermic samples underwent rapid freeze and thaw. Motility and viability were evaluated before freezing (after sucrose equilibration) as well as post freezing (after thaw). The 100 mM concentration of sucrose showed better cryoprotectant features compared to that of higher concentrations (200–1000 mM). Sucrose (100 mM)treated sperm maintained low but acceptable motility (30%) and satisfactory viability (60%) after freezing and thawing. The cryoprotectant capacity of sucrose for normozoospermic and oligozoospermic samples were identical. The sucrose method utilizes rapid freezing of a micro volume of sample and thus quickly freezes, thaws, and maximizes recovery of the sperm from the sample.