Biomedical subjects

J B Lessing

Publications and source records attributed to J B Lessing.

242 records · Page 14Linked to original sources

PubMedDate not supplied

Separation of sperm cells by sedimentation technique is not suitable for in vitro fertilization purposes.

Two methods of sperm preparation for in vitro fertilization were compared: the swim-up technique vs. the migration-sedimentation technique. The study comprised fresh semen samples obtained from 25 couples treated in the In Vitro Fertilization Unit. Oocytes aspirated in a single cycle were divided into two groups, each inseminated by sperm prepared by one of these techniques. Motility, degree of motility, and normal morphology were improved by both methods. The improvement was greater when the migration-sedimentation technique was applied. However, fertilization rate was significantly higher after the swim-up technique. In order to clarify this contradiction, an additional group of 26 semen samples was divided and then prepared by the swim-up or migration-sedimentation techniques. Sperm quality was examined up to 72 h after separation. Compared with the swim-up technique, sperm characteristics were better after separation by the migration-sedimentation technique. However, this difference abated after 24 h. The better results of the swim-up technique in the "survival experiment' may explain its improved performance in in vitro fertilization, despite lower separation capacity. Thus, the migration-sedimentation technique is not recommended for sperm preparation in in vitro fertilization.

Cell Separation↗

PubMedDate not supplied

Correlation between sperm penetration into the human zona pellucida and in vitro fertilization rates.

Sperm penetration into the zona pellucida of unfertilized oocytes, and its correlation with in vitro fertilization rates of the sibling oocytes, were assessed. This was performed in order to evaluate the prediction rate of the sperm penetration test into the zona pellucida. Unfertilized oocytes (n = 1872) from 371 cycles were pipetted through a microcapillary, and the remaining sperm cells penetrating the zona pellucida were counted. The mean (+/- SD) number of spermatozoa that penetrated the zona pellucida of unfertilized oocytes was 12.9 +/- 16.37. A significant correlation was found between the fertilization rate and the mean number of spermatozoa that penetrated into the zona pellucida of the unfertilized sibling oocytes (r = 0.48; P < 0.001), or the percent of unpenetrated zonae pellucidae in a cohort (r = -0.43; P < 0.001). However, a distinct variation in the number of spermatozoa that penetrated into the zona pellucida was detected. A step-wise regression analysis proved the number of spermatozoa penetrating the zona pellucida to be more predictive for fertilization rates than the variable of percent of unpenetrated zonae pellucidae. The results imply that although there is interdependence between penetration into the zona pellucida and fertilization rate, the predictive value of sperm penetration test for prognosis and future management after the first in vitro fertilization attempt, is limited.

Cohort Studies↗

PubMedDate not supplied

Effect of sperm preparation with TEST yolk buffer on sperm-binding capacity under hemizona assay conditions.

The study was conducted to evaluate the diverse effect and clinical significance of TEST yolk buffer treatment on sperm samples of 128 infertile men. Sperm samples were incubated with TEST yolk buffer and control medium (Ham's F-10) at room temperature for 2 h. The hemizona indices (mean +/- SE) of the TEST yolk buffer and medium-treated sperm samples were 29 +/- 2.3% and 22 +/- 1.6%, respectively. Inspection of the individual response of each sperm sample to TEST yolk buffer revealed that 63 samples (49%) improved (double the interassay variation = 28%) their binding to zona pellucida, 36 (28%) remained unchanged, whereas the binding capacity of 29 samples (23%) decreased. Furthermore, TEST yolk buffer treatment of 24 samples (19%) resulted in an increased binding beyond the hemizona index threshold set up at 23%. This level was previously shown to be the cut-off point between fertile and infertile sperm samples. It was concluded that when applied to an unselected group of infertile men, TEST yolk buffer significantly increased sperm binding capacity to the zona pellucida. However, only 19% of the sperm samples showed improvement with clinical significance. The other sperm samples may have improved, remained unchanged or even deteriorated independently on basic sperm variables. Thus, the effect of TEST yolk buffer treatment on sperm binding should be tested prior to its clinical use to avoid possible damage to certain sperm samples.

Buffers↗

PubMedDate not supplied

The possible association between in vitro fertilization treatments and cancer development.

The objective of this paper is to assess whether ovarian hyperstimulation and in vitro fertilization (IVF) are associated with increased risk of cancer development, using an historical cohort analysis of infertile women who attended the IVF unit, Lis Maternity Hospital Tel Aviv Medical Center, Tel Aviv, Israel. One thousand and 82 women participated in the IVF treatment program between 1984 and 1992. Cancer incidence rates were determined through the National Cancer Registry and were compared to the expected rates with respect to appropriate age and continent of birth. Twenty-one cases of cancer were observed as compared to 11 that were expected (SIR 1.91; 95% CI 1.18-2.91). When cancer cases that were diagnosed within one year of the IVF treatment were excluded from the analysis (SIR = 1.46; 95% CI 0.83-2.36), no significant excess risk of cancer was noted. We conclude that in this cohort of infertile women, the higher than expected cancer rate could not be attributed to IVF treatments. Special attention should be made to women who may be diagnosed with cancer during or shortly after IVF treatment.

Adult↗

PubMedDate not supplied

Intracardiac echogenic focus: no apparent association with structural cardiac abnormality.

OBJECTIVE: The aim of our study was to evaluate whether intracardiac echogenic foci (ICEFs) may be associated with increased risk for structural cardiac anomalies in the low-risk population. METHODS: During a 24-month period, 3,744 low-risk patients were prospectively screened for ICEFs by prenatal sonography. The study group was composed of 138 fetuses (3.7%) with ICEF. The control group was composed of 167 fetuses without ICEF. In all fetuses a complete echocardiographic evaluation was performed. RESULTS: Among the 138 fetuses in the study group, 108 (78%) ICEFs were found in the left ventricle, 25 (18%) were found in the right ventricle, and 5 (4%) were found to be bilateral. No statistically significant difference was found between the study and the control group regarding the presence of cardiac anomalies. Only 1 case (0.7%) of pulmonic stenosis was found in the study group, compared to 1 case (0.6%) of bicuspid aortic valve in the control group. CONCLUSIONS: We conclude that ICEFs found in low-risk patients are not associated with a significant increase in the risk of cardiac anomalies.

Adult↗

PubMedDate not supplied

Doppler velocimetry of the umbilical artery as a predictor of pregnancy outcome in pregnancies characterized by elevated maternal serum alpha-fetoprotein and normal amniotic fluid alpha-fetoprotein.

OBJECTIVE: Women with elevated maternal serum alpha-fetoprotein (MSAFP) and normal amniotic fluid alpha-fetoprotein (AFAFP) are at an increased risk of an adverse pregnancy outcome. Such MSAFP elevations are probably the consequence of transplacental leakage caused by placental abnormalities. These may result in disturbed bloodflow through placental vessels. The purpose of this study was to assess whether measurement of such disturbances by Doppler velocimetry of the umbilical artery has a predictive value for pregnancy outcome. STUDY DESIGN: The study group consisted of 85 patients, in whom the only finding was elevated maternal serum alpha-fetoprotein. Systolic/diastolic (S/D) ratios were calculated using a continuous wave Doppler measurement of the umbilical artery, performed at 6 to 8-week intervals. Serial results for each individual were incorporated into a single 'Velocimetry Score'. RESULTS: In group B (14 patients) with an abnormally elevated umbilical S/D ratio, a higher incidence of intrauterine growth retardation (42.9%), preterm deliveries (78.6%), and fetal loss (42.9%) was noted, as compared with group A (71 patients) with a normal S/D ratio. CONCLUSIONS: Umbilical artery Doppler velocimetry may serve as a predictor of pregnancy outcome in the high-risk group characterized by elevated MSAFP.

Adult↗

PubMedDate not supplied

Three-generation evaluation of Y-chromosome microdeletion.

Sperm cells can be retrieved directly from the testis (testicular sperm extraction [TESE] procedure) and used for intracytoplasmic sperm injection (ICSI), circumventing underlying spermatogenetic defects. Thus, it is important that added information be available on the genetic defects in men undergoing TESE for the ICSI procedure and on the transmission of genetic factors associated with infertility to the offspring. We report a three-generation genetic analysis of a family with a case of male factor infertility. The proband, previously diagnosed as infertile, was physically examined and laboratory tested for gonadotrophic hormones, semen analysis, karyotype and Y-chromosome microdeletion screening in the blood and testis. The Y-chromosome microdeletion screening was performed by multiplex polymerase chain reaction with 20 Y-chromosome sequenced, tagged sites located at the Y chromosome. A microdeletion including the AZF-c region was detected in the azoospermic patient. His father, four brothers, and three offspring born after ICSI also underwent Y-chromosome microdeletion screening. The genetic analysis of the male members of the patient's family did not reveal similar microdeletions. The newborn male was found to bear a Y-chromosome microdeletion similar to that of his father. The fertilization capacity of the proband testicular microdeleted spermatozoa by the ICSI procedure is described. The transfer of the genetic defect raises the possibility that the son will have the same fertility problem as his father.

Adult↗

PubMedDate not supplied

Morphology of testicular spermatozoa obtained by testicular sperm extraction in obstructive and nonobstructive azoospermic men and its relation to fertilization success in the in vitro fertilization-intracytoplasmic sperm injection system.

The aim of the present study was to evaluate the morphology of testicular spermatozoa by 3 different determinants. Sperm cells were obtained and their morphology was evaluated from 27 testicular sperm extraction (TESE) operations, of which 20 men had nonobstructive azoospermia and 7 had obstructive azoospermia. In 17 cases, 2 biopsies were obtained from 2 different locations of the testis. Only mature spermatozoa presenting full-grown tail (tail dimension about 10-fold greater than the head dimension) were counted. Three characteristics of sperm morphology were evaluated: head dimensions, and acrosome and midpiece irregularities. The percentage of sperm cells with normal morphology (considering the 3 characteristics) in specimens from patients with obstructive and nonobstructive azoospermia were 47% +/- 4.6% and 29 +/- 1.8%, respectively (P < .01). The percentage of spermatozoa with normal head dimensions were 76% +/- 3.2% and 63% +/- 2.6% (P > .05), those with normal acrosome were 58% +/- 4.6% and 41% +/- 3.4% (P < .05), and those with normal midpiece were 74% +/- 4.1% and 67% +/- 1.6% (P > .05), in obstructive and nonobstructive azoospermia, respectively. No significant differences were observed in sperm morphology between different locations of the testis. Sperm morphological characteristics were not associated with fertilization rate in intracytoplasmic sperm injection (ICSI). Follicle-stimulation hormone and luteinizing hormone were inversely correlated with normal morphology of testicular spermatozoa (r = -0.49 and r = -0.47, respectively; P < .05). It can be concluded that a relatively high portion of testicular sperm are morphologically normal. The higher rate of normal spermatozoa in obstructive azoospermia compared with nonobstructive spermatozoa suggests that the factors leading to azoospermia may affect testicular sperm morphology. The morphological characteristics of testicular sperm do not affect fertilization rate in ICSI.

Adult↗