Biomedical subjects
L I Lipshultz
Publications and source records attributed to L I Lipshultz.
Microsatellite instability and defects in mismatch repair proteins: a new aetiology for Sertoli cell-only syndrome.
Microsatellite instability is characteristic of certain types of cancer, and is present in rodents lacking specific DNA mismatch repair proteins. These azoospermic mice exhibit spermatogenic defects similar to some human testicular failure patients. Therefore, we hypothesized that microsatellite instability due to deficiencies in mismatch repair genes might be an unrecognized aetiology of human testicular failure. Because these azoospermic patients are candidates for testicular sperm extraction and ICSI, transmission of mismatch repair defects to the offspring is possible. Seven microsatellite loci were analysed for instability in specimens from 41 testicular failure patients and 20 controls. Blood and testicular DNA were extracted from patient and control specimens, and amplified by PCR targeting seven microsatellite loci. DNA fragment length was analysed with an ABI Prism 310 Genotyping Machine and GeneScan software. Immunohistochemistry was performed on paraffinized testis biopsy sections and cultured testicular fibroblasts from each patient to determine if expression of the mismatch repair proteins hMSH2 and hMLH1 was normal in both somatic and germline cells. Results demonstrate that microsatellite instability and DNA mismatch repair protein defects are present in some azoospermic men, predominantly in Sertoli cell-only patients (P < 0.01 and P < 0.05 respectively). This provides evidence of a previously unrecognized aetiology of testicular failure that may be associated with cancer predisposition.
Is intracytoplasmic sperm injection safe? Current status and future concerns.
In vitro fertilization with intracytoplasmic sperm injection (ICSI) has revolutionized the treatment of patients with severe forms of male infertility. However, because ICSI has been performed for only 10 years, long-term outcomes and risks to offspring remain largely unknown. The fact that ICSI can potentially bypass natural selection barriers to genetic disease transmission has brought a sobering but important impetus to recent research on the risks and outcomes of ICSI. Several studies were done recently to examine specific risks to children born following ICSI. Because of rapid advances in the ICSI procedure itself, studies evaluating the safety of using immature sperm forms from the testis (spermatids, spermatocytes) also have been undertaken. This review summarizes recent studies examining the risks and long-term outcomes to date of in vitro fertilization with ICSI.
Trinucleotide (CAG) repeat polymorphisms in the androgen receptor gene: molecular markers of risk for male infertility.
OBJECTIVE: To determine whether changes in the polymorphic trinucleotide (CAG) tract of the androgen receptor gene are associated with spermatogenic defects in patients with male infertility. DESIGN: Case-control study of two ethnic groups. SETTING: University referral centers for male infertility at Baylor College of Medicine, Houston, Texas, and National University Hospital, Singapore. PARTICIPANT(S): Two hundred and fifteen patients with male infertility and depressed spermatogenesis and 142 fertile controls. MAIN OUTCOME MEASURE(S): Size of androgen receptor CAG alleles according to fluorescent-labeled polymerase chain reaction and automated analysis using Genescan software (PE Biosystems Asia, Singapore), and statistical examination of its relation to clinical variables. RESULT(S): In U.S. patients, the mean androgen receptor CAG length was significantly longer in infertile patients than in fertile controls (21.95 +/- 0.31 vs. 20.72 +/- 0.52). Logistic regression showed that each unit increase in CAG length was associated with a 20% increase in the odds of being azoospermic. The odds ratio for azoospermia was sevenfold higher for patients with > or =26 CAG repeats than in those with <26 CAG repeats. Although mean CAG length in Singapore patients was longer than in the U.S. samples, long androgen receptor CAG alleles were significantly related to male infertility in both populations. CONCLUSION(S): Long (> or =26) androgen receptor CAG alleles, which are found in up to 25% of azoospermic men, are associated with male infertility and defective spermatogenesis. Conception in these men is possible with assisted reproductive technologies, as many have spermatozoa in their testes.
Multiple pregnancies: action is taking place.
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Increased chromosome X, Y, and 18 nondisjunction in sperm from infertile patients that were identified as normal by strict morphology: implication for intracytoplasmic sperm injection.
OBJECTIVE: To determine the incidence of nondisjunction for chromosomes X, Y, and 18 using fluorescence in situ hybridization (FISH) on morphologically normal sperm from infertile men who are candidates for ICSI. DESIGN: After standard hematoxylin staining, sperm with normal morphology were identified using Kruger's strict morphology criteria. The location of each normal-appearing sperm was recorded using an electronic microstage locator. Slides were subsequently subjected to FISH for detection of chromosomes X, Y, and 18 (control probe). Nuclei were relocated and analyzed under the fluorescent microscope. SETTING: University-affiliated IVF and intracytoplasmic sperm injection program. PATIENT(S): Men classified as infertile on the basis of abnormal strict morphology (<4% by Kruger's criteria). For controls, normal fertile men (n=6) were also analyzed. INTERVENTION(S): Semen smears were obtained retrospectively from infertile (n=8) and fertile (n=6) men. MAIN OUTCOME MEASURE(S): Ploidy of each cell was determined according to the number of signals detected for each probe. RESULT(S): Approximately 100-150 morphologically normal sperm were identified and located in each case. Subsequent FISH analysis of these normal sperm showed aneuploidy to range from 1.8% to 5.5% in the infertile group as compared with 0 to 2.6% among the control fertile group. Statistically significant differences in the incidence of aneuploidy for the sex chromosomes as well as for all three (X, Y, and 18) chromosomes was observed. CONCLUSION(S): Although 95% to 98% of the sperm were found to be normal for X, Y, and 18, our findings show that infertile couples undergoing ICSI are likely to be at an increased risk for having a genetically abnormal conceptus as compared with the fertile controls. These results demonstrate that normal morphology is not an absolute indicator for the selection of genetically normal sperm. Hence, observed pregnancy failures among ICSI patients may in part be due to the selection of aneuploid sperm.
Significance of the polyglutamine tract polymorphism in the androgen receptor.
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Bilateral nerve graft during radical retropubic prostatectomy: 1-year followup.
PURPOSE: With the interposition of a sural nerve graft to replace resected cavernous nerves at radical retropubic prostatectomy, we have previously reported the return of effective erectile function. We determine the efficacy of this procedure in a series of men with at least 1-year followup. MATERIALS AND METHODS: A total of 12 potent men (mean age plus or minus standard deviation 57 +/- 6 years) with clinically localized prostate cancer underwent radical retropubic prostatectomy, with deliberate wide bilateral neurovascular bundle resection and placement of bilateral nerve grafts. A series of patient and partner erectile dysfunction questionnaires, and patient interviews were performed at 3, 6, 12 and 18 months postoperatively. Only results for those men with a followup of 12 months or greater (mean 16 +/- 4) are presented. A control group of 12 men who had undergone bilateral nerve resection but declined nerve graft placement, was also followed. RESULTS: Of the 12 men 4 (33%) had spontaneous medically unassisted erections sufficient for sexual intercourse with vaginal penetration. An additional 5 (42%) men describe "40 to 60%" spontaneous erections, with fullness, no rigidity and not able to penetrate. Overall, 9 (75%) men had return of erectile activity. No demonstrable erections occurred before 5 months postoperatively. The greatest return of function was observed at 14 to 18 months after surgery. CONCLUSIONS: This surgical technique has minimal morbidity and represents a significant advance in prostate cancer surgery in men requiring bilateral nerve resection. Our study clearly demonstrates recovery of erectile function in men who underwent bilateral nerve graft placement during radical retropubic prostatectomy when both cavernous nerves were deliberately resected.
Side-effect profile of sildenafil citrate (Viagra) in clinical practice.
OBJECTIVES: Sildenafil citrate (Viagra) has been shown to be an effective treatment for erectile dysfunction. Initial studies reported a high tolerability and low incidence of certain characteristic adverse reactions. We sought to evaluate the incidence of side effects of sildenafil citrate, independent of industry support and constraints, utilizing a heterogeneous cohort of patients from a university-based practice. METHODS: A prospective, open-label, flexible-dose study of 256 patients treated with sildenafil citrate for erectile dysfunction was performed at a single institution. The patients were questioned explicitly about the occurrence of headache, flushing, dyspepsia, nasal congestion, visual changes, and other side effects. RESULTS: The adverse reactions most commonly observed were flushing (30.8%), headache (25. 4%), nasal congestion (18.7%), and heartburn (10.5%). All events were short lived and mild in nature. In the present study, 31.6% of patients experienced one or more adverse events. However, no one withdrew from the study because of the severity of these events. There was a significant association between higher doses and the occurrence of side effects. CONCLUSIONS: The incidence of adverse events attributable to sildenafil citrate may be higher than initially reported, but an explanation may be the methodology of data collection and the industry-independent nature of this study. The side-effect profile is dose related and mild. Sildenafil citrate remains a safe and well-tolerated treatment for erectile dysfunction.
Human sperm microinjection into hamster oocytes: a new tool for training and evaluation of the technical proficiency of intracytoplasmic sperm injection.
OBJECTIVE: To design a system for teaching intracytoplasmic sperm injection (ICSI) and to provide a standardized method to assess technical competency. SETTING: University andrology laboratory. DESIGN: Prospective study of method for training ICSI and prediction of ICSI outcome. PATIENT(S): Male infertility candidates for ICSI and fertile donors. INTERVENTION(S): Sperm from 14 fertile donors and 21 oligospermic patients were microinjected into hamster ova. Sperm head decondensation rates (SHD) and oocyte damage rates were measured. Hamster ICSI (HICSI) was used to train technicians, to assess competency, for quality control, and to predict ICSI fertilization. Sperm fertilization potential measured by HICSI was compared with the outcome of ICSI. MAIN OUTCOME MEASURE(S): Sperm head decondensation or fertilization. RESULT(S): Sperm head decondensation was observed in 425 of 773 hamster oocytes with a mean (+/- SD) rate of 60.9 +/- 15.5. Consistency was shown by repetitive testing of the same donor, comparing fresh and frozen semen, and testing of the multiple frozen aliquots of the same ejaculate. Technicians have been trained with this protocol. Excellent initial ICSI success rates for new technicians were demonstrated. Oligospermic semen samples (21 men, 251 hamster ova) tested in the HICSI test exhibited SHD rates from 12% to 100%. The poor outcome of ICSI in clinical cases was predicted by HICSI. CONCLUSION(S): The HICSI provides a method for determining the competency for the ICSI technician and interlaboratory comparison, for the prediction of success of sperm for ICSI.
Contemporary approach to the male infertility evaluation.
Evaluation of infertile couples has revealed that male factor infertility contributes to the problem in up to 50% of cases. Evaluation of the male infertility patient may include endocrine studies, sophisticated semen testing, and select radiographic studies. Reversible and life-threatening causes of male infertility should be identified before proceeding directly to assisted reproductive technology. For cases with irreversible causes, a proper evaluation can identify patients who may be treated with the breakthrough method of intracytoplasmic sperm injection. Many men who were previously thought to be infertile may now initiate their own biologic pregnancies. This article emphasizes the essentials of the contemporary approach to evaluating the male factor in an infertile couple.
Male infertility: recent advances and a look towards the future.
The past decade has witnessed clinical and basic scientific advances that have revolutionized the diagnosis and treatment of the infertile male. Advances in the clinic and laboratory have resulted in men who were previously thought to be hopelessly infertile, but who are now able to conceive their own biologic offspring. In the future, we believe that the laboratory will continue to play a key role in advancing our ability both to diagnose and to treat the infertile male. We summarize here some of the major advances of the past decade that have influenced our treatment and our understanding of the etiology of male infertility. When possible, clinical innovations and advances in basic science are discussed in combination in order to emphasize the translational importance of reproductive research.
Testis biopsy findings in the spinal cord injured patient.
PURPOSE: Azoospermia after electroejaculation in spinal cord injured men may be due to testicular failure or obstruction. These men can initiate pregnancy with assisted reproductive techniques, such as intracytoplasmic sperm injection, but only if sperm are present in the testis biopsy. We analyzed the histopathology of testis biopsies from spinal cord injured men and assessed whether patient factors were predictive of testis biopsy pathology. MATERIALS AND METHODS: A total of 50 paraplegic men undergoing testis biopsy were divided into 2 groups based on normal or abnormal testis histopathology. Patient age, post-injury years, level of lesion, hormonal status and semen analysis results were compared. RESULTS: Spermatogenesis was normal in 28 of the 50 patients. Hypospermatogenesis was exhibited in 15, maturation arrest at the spermatid stage in 6 and maturation arrest at the spermatocyte stage in 1 of the 22 abnormal cases. Nevertheless, mature sperm were identified in 43 of 50 biopsies (normal spermatogenesis and hypospermatogenesis). Men with normal spermatogenesis had better forward progression of sperm and a higher testosterone-to-luteinizing hormone ratio. Otherwise, there was no statistically significant correlation between study variables and testis biopsy results. No factors were predictive of testis biopsy histopathology. CONCLUSIONS: The documentation of mature sperm in 43 of 50 biopsies from spinal cord injured patients suggests that a high rate of sperm retrieval is possible using testicular sperm extraction if sperm cannot be retrieved from the ejaculate. With intracytoplasmic sperm injection techniques the majority of spinal cord injured men retain fertility potential, even if azoospermic following electroejaculation.
Treatment of infertility due to anejaculation in the male with electroejaculation and intracytoplasmic sperm injection.
PURPOSE: We tested the hypothesis that spinal cord injury and/or anejaculation affects the outcome of intracytoplasmic sperm injection (ICSI). MATERIALS AND METHODS: From November 1993 to October 1998 we obtained and prospectively reviewed data on 34 ICSI cycles using electroejaculated sperm, 620 male factor infertility ICSI cycles using normal ejaculated sperm and 120 cases of obstructive azoospermia, in which microsurgical epididymal aspiration and testicular sperm extraction-ICSI were done in 93 and 27, respectively. RESULTS: A total of 34 ICSI cycles were performed in 17 couples with male infertility due to anejaculation secondary to spinal cord injury in 10 patients and retroperitoneal lymph node dissection in 5, and idiopathic in 2. In all 17 couples at least 3 previous intrauterine insemination cycles had failed. After electroejaculation 11 men had oligozoospermia and 6 normal sperm density. Median sperm retrieval volume plus or minus standard deviation was 1.9 +/- 1.9 ml., median sperm concentration 70.7 +/- 60.2 x 106 sperm per ml., median motility 10.7% +/- 10.8% and median forward progression 2.3 +/- 0.5 (scale 1 to 4). In the anejaculation group ICSI resulted in a median fertilization of 60% +/- 28%, 15% pregnancies per cycle and 29% pregnancies per couple. In the control group of 620 ICSI cycles from ejaculated specimens obtained from male patients with infertility median fertilization was 58% +/- 26%, and there were 39% pregnancies per cycle and 47% pregnancies per couple. The rate of pregnancies per embryo transfer and per couple was higher in the control than in the electroejaculation-ICSI group (p <0.05). However, there was no statistically significant difference in the fertilization rate. CONCLUSIONS: ICSI or in vitro fertilization is a viable alternative for patients with anejaculation in whom intrauterine insemination failed. While the fertilization rate is similar in these couples, the pregnancy rate is significantly lower than that achieved with ejaculated specimens from patients with severe male factor infertility. ICSI is a viable alternative for a patient with anejaculation in whom intrauterine insemination or in vitro fertilization failed.
Treatment of erectile dysfunction in men with diabetes.
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Fertilization after standard in vitro fertilization versus intracytoplasmic sperm injection in subfertile males using sibling oocytes.
OBJECTIVE: To compare conventional IVF with ICSI in the subfertile male population using sibling oocytes. Results from males with isolated severe teratozoospermia also are analyzed. DESIGN: Prospective experimental study. SETTING: University based IVF clinic. PATIENT(S): Group A: 18 patients with one or more abnormalities in count, motility, or morphology. Group B: 20 patients with isolated severe teratozoospermia (< or = 4% Kruger Strict Criteria). INTERVENTION(S): Ovulation induction, random allocation of sibling oocytes, and IVF or ICSI. MAIN OUTCOME MEASURE(S): Fertilization rates (fertilization per cycle, fertilization per oocytes, and fertilization per couple) and embryo quality. RESULT(S): In group A, fertilization occurred in 13 of 18 (72%) of IVF cycles and 17 of 18 (94%) of ICSI cycles. Overall, 69 of 120 (58%) oocytes fertilized after IVF, whereas 80 of 131 (61%) fertilized after ICSI. The mean (+/-SEM) percent of oocytes fertilized per couple was 44.6%+/-9.0% with IVF and 62.7%+/-5.6% with ICSI (not statistically significant). In group B, fertilization occurred in 18 of 20 (90%) cycles after IVF and 20 of 20 (100%) cycles with ICSI. Overall, 54 of 113 (48%) of the oocytes fertilized after IVF, whereas 82 of 124 (66%) fertilized with ICSI. The mean (+/-SEM) percent of oocytes fertilized per couple was 50.9%+/-7.1 % with IVF and 66.6%+/-4.7% with ICSI. No statistically significant difference in embryo quality after IVF versus ICSI was demonstrated. CONCLUSION(S): With severe teratozoospermia, ICSI results in higher fertilization rates than conventional IVF, without altering embryo quality. In our subfertile male population, there is a trend toward improved fertilization with ICSI, with less failed fertilization.
Demonstration of testicular apoptosis in human male infertility states using a DNA laddering technique.
DNA laddering, morphometric analysis, and in-situ end labelling of testis biopsy tissue obtained from azoospermic or severely oligozoospermic men revealed increased apoptosis frequency, implicating a possible role of apoptosis in the pathogenesis of human male infertility.
The role of autosomal cell apoptosis regulator genes in human spermatogenesis.
Immunohistochemical analysis of the expression of the autosomal apoptosis regulator genes, BAX, bcl-2, p53, and cyclic-AMP responsive element modulator (CREM) in testis biopsies from infertile men demonstrated that BAX, bcl-2, and p53 immunoreactivity was absent irrespective of seminiferous tubule histology. In contrast, cell-specific CREM immunoreactivity in round spermatids, with complete absence of CREM in patient biopsies showing spermatocyte maturation arrest and Sertoli cell only, was evident, suggesting a possible role of autosomal genes in the regulation of apoptosis in human spermatogenesis regulation.