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Biomedical subjects

A Lewin

Publications and source records attributed to A Lewin.

At least 37 records · Page 2Linked to original sources
PubMed1998

A birth in non-mosaic Klinefelter's syndrome after testicular fine needle aspiration, intracytoplasmic sperm injection and preimplantation genetic diagnosis.

Non-mosaic Klinefelter patients are generally azoospermic due to primary testicular failure. Nevertheless, in some cases, testicular spermatozoa may be recovered and utilized to fertilize oocytes via intracytoplasmic sperm injection (ICSI). As the risk for an increased number of gonosomes in these spermatozoa is unclear, preimplantation genetic diagnosis (PGD) may be attempted in the resulting embryos. In the present study, we report our experience with the combined approach of sperm retrieval by testicular fine needle aspiration (FNA), ICSI and PGD in seven consecutive non-mosaic Klinefelter individuals. In four patients, between one and five spermatozoa were retrieved in five out of nine consecutive attempts. In a fifth patient, only 10 round spermatids could be isolated. Mature spermatozoa were injected into a total of 16 metaphase-II oocytes, of which 11 (69%) remained intact. Two distinct pronuclei (2PN) were observed in four oocytes (36%) while a single pronucleus (1PN) was documented in two oocytes. Five cleavage stage embryos developed from the oocytes of two couples. Upon the request of one couple, their three embryos (two derived from 1PN oocytes) were transferred without PGD but pregnancy was not achieved. PGD by fluorescence in-situ hybridization (FISH) was performed in the two embryos of the other couple which were derived from normal fertilization. PGD results of one embryo were 18,18,X,X,Y, the embryo was not transferred and FISH analysis of the remaining blastomeres identified variable chromosome numbers in the nuclei. The second embryo was diagnosed as normal and was transferred, resulting in a successful pregnancy and birth. In conclusion, the results of this report indicate that a pregnancy and birth may be attained in azoospermic non-mosaic Klinefelter individuals by testicular FNA combined with ICSI. Due to the unknown risk of gonosomes aneuploidy in embryos from Klinefelter patients, PGD or prenatal diagnosis should be recommended.

Adult↗
PubMed1998

Intracytoplasmic sperm injection allows fertilization and development of a chromosomally balanced embryo from a binovular zona pellucida.

A binovular zona pellucida was found in two in-vitro fertilization (IVF) treatment cycles. In both cases, two oocytes of slightly unequal size were enclosed within a single zona pellucida, the larger oocyte appearing as a metaphase II oocyte while the smaller one as an immature oocyte with a germinal vesicle. Intracytoplasmic sperm injection performed in the mature oocyte of each pair led to normal fertilization and embryonic development in both cases. Results of genetic analysis performed by fluorescence in-situ hybridization in one of the two treatment cycles were consistent with a diploid chromosomal status of both the non-injected immature oocyte as well as the embryo which developed following the microinjection. These results indicate that, in this case, the binovular zona pellucida was most probably created when granulosa cells failed to separate two distinct oocytes during follicular formation. It may also imply that selective fertilization of a single mature oocyte in a binovular zona pellucida by intracytoplasmic sperm injection can lead to the development of a chromosomally balanced embryo and can prevent the undesired consequences that may result if the two oocytes are fertilized in the course of standard IVF.

Adult↗
PubMed1998

Assisted reproduction for the treatment of azoospermia.

Azoospermia, the most severe form of male infertility, is caused by obstructions in the genital tract or by testicular failure. Microsurgical techniques are available for the correction of some of these obstructions but no effective treatment is available for testicular failure. In recent years, methods have been developed for direct surgical sperm sampling from either the epididymis or the testis to be used by intracytoplasmic sperm injection. The main approach proven to be effective for the retrieval of spermatozoa from the epididymis in patients with obstructive azoospermia is microsurgical epididymal sperm aspiration, although recently the retrieval of spermatozoa by fine needle aspiration was shown to be equally effective. Recovery of spermatozoa is also now performed in patients with severely deficient spermatogenesis using testicular open biopsy as well as aspiration by fine needle. The ultimate choice of sperm retrieval method in these patients will depend not only on sperm availability, but also on the physiological consequences of the different techniques on testicular function. This article summarizes the recent advances achieved in the treatment of azoospermic patients using these assisted reproduction surgical techniques.

Humans↗
PubMed1998

Inhibition of RNA synthesis as a therapeutic strategy against Aspergillus and Fusarium: demonstration of in vitro synergy between rifabutin and amphotericin B.

We investigated the in vitro antifungal activity of amphotericin B, alone and in combination with rifabutin, an inhibitor of bacterial RNA polymerase, against 26 clinical isolates of Aspergillus and 25 clinical isolates of Fusarium. Synergy or additivism between these drugs was demonstrated against all isolates tested. Amphotericin B MICs were reduced upon combination with rifabutin from a mean of 0.65 microg/ml to a mean of 0.16 microg/ml against Aspergillus, and from a mean of 0.97 microg/ml to a mean of 0.39 microLg/ml against Fusarium (P < 0.000001 for both). Similarly, the MICs of rifabutin were reduced upon combination with amphotericin B from a mean of >32 microg/ml to a mean of 1.1 microg/ml against both fungi (P < 0.000001 for both). These positive interactions were corroborated by a colony count study with two Fusarium isolates, for which treatment with the combination of subinhibitory concentrations of amphotericin B (at concentrations 2- and 4-fold less than the MIC) and rifabutin (at concentrations ranging from 4- to 64-fold less than the MIC) resulted in 3.2-log reductions in colony counts compared to those after treatment with either drug alone. Inhibition of RNA synthesis was shown to be the mechanism of antifungal activity. These results suggest that inhibition of fungal RNA synthesis might be a potential target for antifungal therapy.

Amphotericin B↗
PubMed1998

Selective degradation of nonsense beta-phosphodiesterase mRNA in the heterozygous rd mouse.

PURPOSE: To investigate the molecular mechanism relating phenotype and genotype in the rd mouse, mRNA and pre-mRNA levels derived from the wild-type and position-347 nonsense mutant beta-phosphodiesterase (beta-PDE) genes were determined and compared with the corresponding gene copy ratios. METHODS: Total RNA and genomic DNA was isolated from the retinas of three heterozygous rd/+ mouse strains. For each, quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the ratio of wild-type and rd beta-phosphodiesterase pre-mRNA and mature mRNA. The gene copy ratio between wild-type and rd beta-PDE was also determined by quantitative PCR. RESULTS: The pre-mRNA ratio of wild-type versus nonsense mutant was close to 1:1, whereas the corresponding mRNA ratio was greater than 3:1, even though the gene copy ratio was confirmed to be 1:1. CONCLUSIONS: The equivalence of pre-mRNA ratio level for wild-type and nonsense mutant in the rd/+ retina indicates that both genes were transcribed at similar levels. Thus, neither the nonsense mutation at position 347 nor the intron 1 retroviral insertion also present in the rd gene seem to have affected gene transcription. In contrast, the strain-independent bias favoring wild-type mature mRNA in vivo suggests a specific degradation of mutant transcript during or after pre-mRNA splicing. This allele-specific degradation serves to decrease mutant transcript levels dramatically in all rd strains, and suggests that photoreceptor cells have the capacity to reduce the level of an mRNA containing a nonsense mutation.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1997

IkappaBalpha overexpression delays tumor formation in v-rel transgenic mice.

We have previously shown that transgenic mice expressing the oncoprotein v-Rel under the control of a T cell-specific promoter develop T cell lymphomas. Tumor formation was correlated with the presence of p50/v-Rel and v-Rel/v-Rel nuclear kappaB-binding activity. Since experimental evidence has led to the suggestion of a potential tumor suppressor activity for IkappaBalpha, we have studied the role of IkappaBalpha in the transforming activity of v-Rel by overexpressing IkappaBalpha in v-rel transgenic mice. Overexpression of IkappaBalpha in v-rel transgenic mice resulted in an extended survival, and the development of cutaneous T cell lymphomas of CD8(+)CD4(-) phenotype. These phenotypic alterations were associated with a dramatic reduction of p50/v-Rel, but not v-Rel/v-Rel nuclear DNA binding activity and an increased expression of the intercellular adhesion molecule 1. Our results indicate that v-Rel homodimers are active in transformation and that the capacity of v-Rel-containing complexes to escape the inhibitory effect of IkappaBalpha may be a key element in its transforming capability.

Animals↗
PubMed1997

The role of uterine straightening by passive bladder distension before embryo transfer in IVF cycles.

PURPOSE: The present study investigated the effect of bladder distension on in vitro fertilization and embryo transfer (IVF-ET) results. METHODS: The study comprised 796 patients after successful transvaginal oocyte pickup and IVF, who, on the basis of bladder filling for ET, were divided into two groups. In group E, 385 patients underwent ET with an empty bladder, and in group F, 411 patients underwent ET with a full bladder. RESULTS: Sixty-four pregnancies were achieved in group E (16.6%), compared to 110 pregnancies in group F (26.8%, P = 0.006). A similar pregnancy loss rate was observed in both groups, 13 in group E (20.3%) and 29 in group F (26.4%; P = NS). CONCLUSIONS: A significantly higher pregnancy rate was achieved with routine bladder distension before ET, probably attributable to the smooth and easy insertion of the ET catheter.

Adult↗
PubMed1997

Is there really a decrease in sperm parameters among healthy young men? A survey of sperm donations during 15 years.

PURPOSE: Our purpose was to measure changes in semen quality and quantity in young healthy sperm donors in Jerusalem over time. METHODS: A retrospective analysis of semen parameters over 15 years using linear regression analysis, in a single sperm bank in a tertiary university center. Study population consisted of 188 young, healthy medical students, aged 20 to 30 years, who donated sperm samples for Artificial insemination between 1980 and 1995. RESULTS: There were no statistically significant changes in semen concentration and motility during the study period. The mean semen volume increased by 0.1 ml (5.1%) per year (P < 0.0001), with a concomitant mean rise of 5.8 x 10(6) (7.7%) per year in total motile sperm count. The percentage normal morphology decreased by a mean of 1.04% per year during the entire period (P < 0.0001). CONCLUSIONS: During the past 15 years, there has been an increase in total motile sperm count, secondary to an increase in semen volume, and a decline in normal morphology that are independent of the age and the duration of abstinence in fertile men.

Adult↗
PubMed1997

Is the obstetric outcome of in vitro fertilized singleton gestations different from natural ones? A controlled study.

OBJECTIVE: To determine whether singleton IVF pregnancies carry adverse maternal or fetal outcome when compared with naturally conceived gestations. DESIGN: An analysis of the obstetric outcome of singleton IVF pregnancies in comparison with matched, naturally conceived singleton controls. SETTING: In vitro fertilization unit and obstetric service at a tertiary medical center. PATIENT(S): Two hundred sixty consecutive singleton IVF pregnancies and 260 naturally conceived singleton controls matched 1:1 for maternal age, parity, ethnic origin, and location and date of delivery. INTERVENTION(S): In vitro fertilization-ET. MAIN OUTCOME MEASURE(S): The rate of antenatal obstetric complications, nonvertex presentation, cesarean section, preterm labor, low birth weight, small and very small for gestational age, neonatal intensive care unit admissions, and perinatal mortality. RESULT(S): The rates of most antenatal complications were similar in both groups. Urinary tract infection was the only complication diagnosed significantly more frequently after IVF (7.3% versus 1.2%); however, the rates of severe urinary tract infection necessitating hospitalization were similar. The incidence of nonvertex presentation was also similar. The cesarean section rate was significantly higher among IVF patients (41.9% versus 15.5%). The rates of preterm labor, low birth weight, small and very small for gestational age, neonatal intensive care unit admissions, and perinatal mortality were comparable. CONCLUSION(S): When controlling for maternal age, parity, ethnic origin, and location and date of delivery, singleton IVF pregnancies do not carry an increased risk for prematurity, low birth weight, or maternal or fetal complications. Still, these pregnancies are associated with a high rate of cesarean sections.

Adult↗
PubMed1997

The effect of coenzyme Q10 on sperm motility and function.

In sperm cells, the majority of coenzyme Q10 (CoQ10) an energy promoting agent and antioxidant, is concentrated in the mitochondria of the midpiece, so that the energy for movement and all other energy-dependent processes in the sperm cell also depend on the availability of CoQ10. The reduced form of CoQ10-ubiquinol also acts as an antioxidant, preventing lipid peroxidation in sperm membranes. The objective of the study was to evaluate the effect of CoQ10 on sperm motility in vitro, after incubation with 38 samples of asthenospermic and normal motility sperm, and to evaluate the effect of CoQ10 administration in vivo in 17 patients with low fertilization rates after in vitro fertilization with intracytoplasmic sperm injection (ICSI) for male factor infertility. All 38 sperm samples from patients registered in our infertility clinic had normal concentrations and morphology. Of these, 16 patients had normal motility (mean 47.5%) and 22 patients were asthenospermic (mean motility 19.1%). Sperm samples were divided into four equal parts and incubated for 24 h in: HAM's medium alone, in HAM's medium with 1% DMSO and HAM's with 5 microM or 50 microM CoQ10. While no significant change in motility after incubation was observed in the samples with initial normal motility, a significant increase in motility was observed in the 50 microM CoQ10 subgroup of sperm from asthenospermic men, with a motility rate of 35.7 +/- 19.5%, as compared to 19.1 +/- 9.3% in the controls (P < 0.05). The 17 patients with low fertilization rates after ICSI were treated with oral CoQ10, 60 mg/day, for a mean of 103 days before the next ICSI treatment. No significant change was noted in most sperm parameters, but a significant improvement was noted in fertilization rates, from a mean of 10.3 +/- 10.5% in their previous cycles, to 26.3 +/- 22.8% after CoQ10 (P < 0.05). In conclusion, the administration of CoQ10 may result in improvement in sperm functions in selective patients. Further investigation into the mechanisms related to these effects is needed.

Administration, Oral↗
PubMed1997

Osteopetrosis in mice lacking NF-kappaB1 and NF-kappaB2.

The nfkb1 and nfkb2 genes encode closely related products regulating immune and inflammatory responses. Their role during development and differentiation remains unclear. The generation of nfkb1 null mice (p50-/-) resulted in altered immune responses, but had no effect on development. Similarly, nfkb2 knockout mice (p52-/-) did not show developmental defects (J.C. et al., manuscript submitted). We have investigated the potential for in vivo compensatory functions of these genes by generating double-knockout mice. The surprising result was that the animals developed osteopetrosis because of a defect in osteoclast differentiation, suggesting redundant functions of NF-kappaB1 and NF-kappaB2 proteins in the development of this cell lineage. The osteopetrotic phenotype was rescued by bone marrow transplantation, indicating that the hematopoietic component was impaired. These results define a new mouse osteopetrotic mutant and implicate NF-kappaB proteins in bone development, raising new directions in the treatment of bone disorders.

Animals↗
PubMed1997

Intracytoplasmic sperm injection combined with preimplantation genetic diagnosis for the prevention of recurrent gestational trophoblastic disease.

A strategy for the prevention of repeated molar pregnancies by using intracytoplasmic sperm injection (ICSI) coupled with preimplantation genetic diagnosis (PGD) with fluorescence in-situ hybridization (FISH) was developed. In this approach, complete moles which arise from dispermic fertilization are avoided by the use of ICSI. ICSI is followed by preimplantation selection against the transfer of 46,XX embryos, thus preventing complete moles resulting from a fertilization of an inactive oocyte, by a haploid X-bearing spermatozoon which subsequently duplicates. Triploid partial moles which arise mainly from dispermic fertilization may also be prevented by ICSI. The preimplantation confirmation of diploidy by FISH guards against triploid partial moles which may result from mechanisms other than dispermic fertilization. The employment of this strategy in an attempt to prevent a repeated event of molar pregnancy in a patient with a history of two previous episodes of gestational trophoblastic disease is reported.

Adult↗
PubMed1996

[Endometrial measurement by transvaginal sonography in postmenopausal bleeding].

We evaluated the role of transvaginal sonography (TVS) in the investigation of postmenopausal bleeding (PMB) in 50 women with PMB and 25 asymptomatic postmenopausal women presenting for periodic check-up, who served as controls. All those with PMB had a diagnostic curettage or hysterectomy within a week of TVS examination. Measurement of endometrial thickness was compared with the histopathological diagnosis of the endometrium. Of the 32 patients whose endometrial thickness was more than 5 mm, 22 had pathological changes in the endometrium. These included 6 cases of endometrial cancer and 16 with benign changes. All 18 patients of the PMB group with endometrial thickness less than 5 mm had normal endometrial histology. Endometrial thickness in all asymptomatic controls was less than 5 mm. Our results showed endometrial thickness greater than 5 mm to be 100% sensitive and 64% specific in identifying endometrial pathology. TVS follow-up without curettage may be considered for PMB patients with uniform endometrium less than 5 mm thick.

Aged↗
PubMed1996

Use of alfentanil for in vitro fertilization oocyte retrieval.

STUDY OBJECTIVES: To determine alfentanil levels with a specific radioimmunoassay in serum and ovarian follicular fluid. DESIGN: Observational study. SETTING: University hospital. PATIENTS: 14 ASA status I women undergoing oocyte retrieval for in vitro fertilization. INTERVENTIONS: General anesthesia was induced with alfentanil 15 micrograms/kg and midazolam 2 mg and maintained with alfentanil 0.5 mg, 60% nitrous oxide (N2O) in oxygen (O2) and midazolam up to a total of 4 mg. Oocyte retrieval was performed using a transvaginal ultrasound guided technique, 34 to 36 hours after human chorionic gonadotrophin administration. MEASUREMENTS AND MAIN RESULTS: Mean procedure time for oocyte retrieval was 18 +/- 2.4 (SEM) minutes. All patients were fully awake within 5 minutes and all patients except one were able to move from the operating table to the stretcher with minimal help. Mean total protein concentration in the follicular fluid was 3.8 +/- 0.4 mg%. Maximal serum alfentanil concentrations (Cmax) were attained 5 minutes after start of the procedure (tmax) and were 92 +/- 20 ng/ml. In contrast, alfentanil concentrations in the follicular fluid increased constantly throughout the procedure up to 8.9 +/- 0.8 ng/ml at 15 minutes. Clinical pregnancy rate was 3 of 14 patients. CONCLUSION: It is evident that during the oocyte retrieval procedure, the alfentanil concentrations in the follicular fluid are about ten-fold smaller than the serum alfentanil concentrations at the same time points. Similar pharmacokinetics have been shown when propofol was used as anesthetic. The low accumulation of alfentanil in the follicular fluid increases the attractiveness of alfentanil for anesthesia during oocyte retrieval for in vitro fertilization.

Adult↗
PubMed1996

Increased levels of redox-active iron in follicular fluid: a possible cause of free radical-mediated infertility in beta-thalassemia major.

OBJECTIVE: Our purpose was to investigate the follicular fluid parameters associated with redox activity and the consequent production of the deleterious hydroxyl radical in beta-thalassemia major. STUDY DESIGN: The levels of ferritin, total iron, total copper, and redox-active iron were measured in follicular fluid aspirated from three follicles during three consecutive ovum pickups from a patient with beta-thalassemia major and were compared with the levels in nine follicles aspirates from nine healthy control patients. The redox activity in the follicular fluid samples was monitored by the extent of follicular fluid-mediated deoxyribonucleic acid degradation and salicylate hydroxylation. RESULTS: Total iron and ferritin concentrations were elevated in thalassemic follicular fluid samples compared with control samples (6.7 fold, and 53.3-fold, respectively), whereas the total copper concentration was similar. Thalassemic follicular fluid samples exhibited a marked increase of redox activity, indicating a higher potential of free radical production leading to deoxyribonucleic acid degradation. Likewise, free radical-induced conversion of salicylate to dihydroxybenzoic acid derivatives was enhanced in the thalassemic follicular fluid samples compared with controls (2,3-dihydroxybenzoic acid: 67.7 +/- 22 vs 20.3 +/- 12.9 ng/mg protein; 2,5-dihydroxybenzoic acid: 101.6 +/- 25.9 vs 4.42 +/- 2.7 ng/mg protein). CONCLUSIONS: The increased level of redox activity found in the follicular fluid from a patient with beta-thalassemia major focuses the attention on the small fraction of redox-active iron ions as mediators of free radical production, inducing tissue injury and possibly contributing to impairment of reproduction in these patients.

Adult↗
PubMed1996

Ovarian cysts in premenopausal and postmenopausal tamoxifen-treated women with breast cancer.

OBJECTIVE: Our purpose was to investigate the frequency of ovarian cysts in tamoxifen-treated breast cancer patients. STUDY DESIGN: The study population included 95 consecutive tamoxifen-treated premenopausal and postmenopausal women with breast cancer who were followed up by the outpatient clinic at the Hadassah University Hospital between September 1990 and June 1992. Tamoxifen was administered orally (20 mg/day). All patients underwent a pelvic examination and vaginal ultrasonography with a 5 MHz vaginal probe. RESULTS: During the study 11 of 95 tamoxifen-treated breast cancer patients (11%) had ovarian cysts. Five cysts were detected in postmenopausal women (6.3% of the postmenopausal women) and six in premenopausal women (37.5% of the premenopausal women). In postmenopausal and premenopausal women the mean tamoxifen treatment interval was 19.4 +/- 7.8 months (range 4 to 48 months) and 28 +/- 6.1 months (range 12 to 54 months), respectively (p = 0.41). In 8 of the 11 patients the ovarian cystic enlargement disappeared after cessation of tamoxifen treatment. Two patients underwent laparotomy because of persistent cysts and the third because of a rapidly growing myoma. The three cysts were found to be benign. CONCLUSION: Ovarian cysts are a common side effect of tamoxifen treatment. The ovarian cysts can develop in tamoxifen-treated premenopausal as well as postmenopausal women with breast cancer. Most of the tamoxifen-associated cysts disappear after tamoxifen treatment is abandoned.

Adult↗
PubMed1996

Ruptured tubo-ovarian abscess complicating transcervical cryopreserved embryo transfer.

OBJECTIVE: To present a rare infectious complication related to transcervical ET, without prior transvaginal puncture. DESIGN: Case report. SETTING: Hadassah University Hospital, IVF-ET unit. PATIENT: One patient undergoing cryopreserved-thawed ET. INTERVENTIONS: Artificial preparation of the endometrium with E2 and P, followed by transcervical intrauterine cryopreserved-thawed embryo transfer. RESULTS: After ET, severe pelvic inflammatory disease (PID) with ruptured tubo-ovarian abscess was diagnosed and treated. CONCLUSIONS: Severe PID including tubo-ovarian abscess formation should be considered a potential complication after ET, even without transvaginal oocyte aspiration.

Abscess↗