The HERA (Hyper-response Risk Assessment) Delphi consensus for the management of hyper-responders in in vitro fertilization.

PURPOSE: To provide agreed-upon guidelines on the management of a hyper-responsive patient undergoing ovarian stimulation (OS) METHODS: A literature search was performed regarding the management of hyper-response to OS for assisted reproductive technology. A scientific committee consisting of 4 experts discussed, amended, and selected the final statements. A priori, it was decided that consensus would be reached when ≥66% of the participants agreed, and ≤3 rounds would be used to obtain this consensus. A total of 28/31 experts responded (selected for global coverage), anonymous to each other. RESULTS: A total of 26/28 statements reached consensus. The most relevant are summarized here. The target number of oocytes to be collected in a stimulation cycle for IVF in an anticipated hyper-responder is 15-19 (89.3% consensus). For a potential hyper-responder, it is preferable to achieve a hyper-response and freeze all than aim for a fresh transfer (71.4% consensus). GnRH agonists should be avoided for pituitary suppression in anticipated hyper-responders performing IVF (96.4% consensus). The preferred starting dose in the first IVF stimulation cycle of an anticipated hyper-responder of average weight is 150 IU/day (82.1% consensus). ICoasting in order to decrease the risk of OHSS should not be used (89.7% consensus). Metformin should be added before/during ovarian stimulation to anticipated hyper-responders only if the patient has PCOS and is insulin resistant (82.1% consensus). In the case of a hyper-response, a dopaminergic agent should be used only if hCG will be used as a trigger (including dual/double trigger) with or without a fresh transfer (67.9% consensus). After using a GnRH agonist trigger due to a perceived risk of OHSS, luteal phase rescue with hCG and an attempt of a fresh transfer is discouraged regardless of the number of oocytes collected (72.4% consensus). The choice of the FET protocol is not influenced by the fact that the patient is a hyper-responder (82.8% consensus). In the cases of freeze all due to OHSS risk, a FET cycle can be performed in the immediate first menstrual cycle (92.9% consensus). CONCLUSION: These guidelines for the management of hyper-response can be useful for tailoring patient care and for harmonizing future research.

The HERA (Hyper-response Risk Assessment) Delphi consensus definition of hyper-responders for in-vitro fertilization.

PURPOSE: To provide an agreed upon definition of hyper-response for women undergoing ovarian stimulation (OS)? METHODS: A literature search was performed regarding hyper-response to ovarian stimulation for assisted reproductive technology. A scientific committee consisting of 5 experts discussed, amended, and selected the final statements in the questionnaire for the first round of the Delphi consensus. The questionnaire was distributed to 31 experts, 22 of whom responded (with representation selected for global coverage), each anonymous to the others. A priori, it was decided that consensus would be reached when ≥ 66% of the participants agreed and ≤ 3 rounds would be used to obtain this consensus. RESULTS: 17/18 statements reached consensus. The most relevant are summarized here. (I) Definition of a hyper-response: Collection of ≥ 15 oocytes is characterized as a hyper-response (72.7% agreement). OHSS is not relevant for the definition of hyper-response if the number of collected oocytes is above a threshold (≥ 15) (77.3% agreement). The most important factor in defining a hyper-response during stimulation is the number of follicles ≥ 10 mm in mean diameter (86.4% agreement). (II) Risk factors for hyper-response: AMH values (95.5% agreement), AFC (95.5% agreement), patient's age (77.3% agreement) but not ovarian volume (72.7% agreement). In a patient without previous ovarian stimulation, the most important risk factor for a hyper-response is the antral follicular count (AFC) (68.2% agreement). In a patient without previous ovarian stimulation, when AMH and AFC are discordant, one suggesting a hyper-response and the other not, AFC is the more reliable marker (68.2% agreement). The lowest serum AMH value that would place one at risk for a hyper-response is ≥ 2 ng/ml (14.3 pmol/L) (72.7% agreement). The lowest AFC that would place one at risk for a hyper-response is ≥ 18 (81.8% agreement). Women with polycystic ovarian syndrome (PCOS) as per Rotterdam criteria are at a higher risk of hyper-response than women without PCOS with equivalent follicle counts and gonadotropin doses during ovarian stimulation for IVF (86.4% agreement). No consensus was reached regarding the number of growing follicles ≥ 10 mm that would define a hyper-response. CONCLUSION: The definition of hyper-response and its risk factors can be useful for harmonizing research, improving understanding of the subject, and tailoring patient care.

Human sperm handling in intracytoplasmic sperm injection processes: In vitro studies on mouse oocyte activation, embryo development competence and sperm oxidation-reduction potential.

Polyvinylpyrrolidone (PVP) and hyaluronic acid (HA) are routinely used in handling spermatozoa for intracytoplasmic sperm injection (ICSI). As there are still concerns about possible adverse effects on the embryo, this study investigated sperm handling in a mouse ICSI model to (i) evaluate oocyte activation after injection of spermatozoa selected for rotational or linear motion in PVP; (ii) assess the effect of sperm selection in PVP, HA and medium on oocyte activation; (iii) examine the effects of PVP and HA on parthenogenetic oocyte activation and embryo development; and (iv) assess the oxidation-reduction potential (ORP) of spermatozoa exposed to PVP, HA or medium. Oocyte activation was higher when spermatozoa exhibited rotational motion rather than linear motion (79% vs. 52%; p = .05). There was no difference in oocyte activation and embryo development after parthenogenetic oocyte activation after sperm injection using PVP, HA or medium-incubated spermatozoa. PVP-selected spermatozoa exhibited lower (p < .0001) ORP levels than using HA. Thus, results indicate that the sperm handling method and the type of medium used impact ICSI outcomes. Overall, sperm incubation in PVP, HA and medium yields similar outcomes with regard to oocyte activation and embryo development. However, PVP provides more antioxidative protection than HA and should therefore be preferred for sperm manipulation.

Association between promoter methylation of MLH1 and MSH2 and reactive oxygen species in oligozoospermic men-A pilot study.

MLH1 and MSH2 are important genes for DNA mismatch repair and crossing over during meiosis and are implicated in male infertility. Therefore, the methylation patterns of the DNA mismatch repair genes MLH1 and MSH2 in oligozoospermic males were investigated. Ten oligozoospermic patients and 29 normozoospermic donors were analysed. Methylation profiles of the MLH1 and MSH2 promotors were analysed. In addition, sperm motility and seminal reactive oxygen species (ROS) were recorded. Receiver operating characteristic (ROC) analysis was conducted to determine the accuracy of the DNA methylation status of MLH1 and MSH2 to distinguish between oligozoospermic and normozoospermic men. In oligozoospermic men, MLH1 was significantly (p = .0013) more methylated compared to normozoospermic men. Additionally, there was a significant positive association (r = .384; p = .0159) between seminal ROS levels and MLH1 methylation. Contrary, no association between MSH2 methylation and oligozoospermia was found. ROC curve analysis for methylation status of MLH1 was significant (p = .0275) with an area under the curve of 61.1%, a sensitivity of 22.2% and a specificity of 100.0%. This pilot study indicates oligozoospermic patients have more methylation of MLH1 than normozoospermic patients. Whether hypermethylation of the MLH1 promoter plays a role in repairing relevant mismatches of sperm DNA strands in idiopathic oligozoospermia warrants further investigation.

Ascorbic acid reduces redox potential in human spermatozoa subjected to heat-induced oxidative stress.

Oxidation-reduction potential (ORP) is a new measure of oxidative stress. It is a balance between the total available oxidants and reductants. This study measures the efficiency of ascorbic acid (AA) against oxidative stress induced by either heat alone or heat and hydrogen peroxide in sperm suspensions using the MiOXSYS System. Two concentrations of ascorbic acid (400 and 600 µmol/L) were tested against heat- and heat plus hydrogen peroxide-induced oxidative stress in sperm suspensions after 2 and 4 hr of incubation. Sperm motility and static oxidation reduction potential (sORP) were measured at 2 and 4 hr of incubation at three different temperatures. A significant decrease in sORP was observed as a function of AA concentration. The 600 µmol/L AA had more pronounced reduction in sORP compared to 400 µmol/L AA (p = .001). Significant decreases in sperm motility ranging from 4.89% to 14.02% were observed both as a function of incubation time and addition of H2 O2 (p < .001). Ascorbic acid is efficacious to reduce heat-induced oxidative stress in sperm preparations in vitro. The supplementation of ascorbic acid may be advantageous for semen preparations in IUI, IVF and ICSI.

Characterisation of a subpopulation of sperm with massive nuclear damage, as recognised with the sperm chromatin dispersion test.

Assessment of human sperm DNA fragmentation by the sperm chromatin dispersion (SCD) test is based on the detection of haloes of spreading DNA loops after sequential DNA denaturing and protamine removal. After the SCD test, sperm without DNA fragmentation show chromatin haloes emerging from the central nuclear core, while sperm containing fragmented DNA present small or no haloes. The nuclear degraded sperm are recognised as a differentiated category within the sperm with fragmented DNA, whose cores appear irregularly and/or faintly stained. This subpopulation is more prevalent in patients with varicocele. Protein staining with 2.7-dibrom-4-hydroxy-mercury-fluorescein demonstrated that degraded sperm intensely lose nuclear core proteins after the SCD processing. Moreover, degraded sperm are 65% more faintly labelled for DNA breaks after in situ nick translation (ISNT) on average, due to extensive DNA loss. A two-dimensional comet assay under sequential neutral and alkaline conditions demonstrated that degraded sperm contain both massive double- and single-strand DNA breaks. The degraded sperm appear as a subpopulation with stronger nuclear damage, affecting both DNA and protein fractions, possibly due to intense intratesticular oxidative stress, what could explain its higher proportion in patients with varicocele.

Effects of pentoxifylline treatment before freezing on motility, viability and acrosome status of poor quality human spermatozoa cryopreserved by the liquid nitrogen vapor method.

The objective of the present study was to investigate the effects of the direct addition of pentoxifylline (PF) to the ejaculates of men with poor sperm quality before freezing on post-thaw sperm motility, viability, acrosome integrity, and agonist-induced acrosome reaction. Semen specimens from 16 infertile men with impaired sperm count and motility (oligoasthenozoospermia) were divided into two equal aliquots: one received no treatment (control) while the other was incubated with 5 mM PF (treated). Both aliquots were cryopreserved by the liquid nitrogen vapor method. Motility was assessed according to WHO criteria. Acrosome integrity and spontaneous and calcium ionophore-induced acrosome reactions were assessed with fluorescein isothiocyanate-conjugated peanut agglutinin combined with a supra-vital dye (Hoechst-33258). Cryopreservation impaired sperm motility (percentage reduction: 87.4 (interquartile range, IQ: 70.3-92.9) vs 89.1 (IQ: 72.7-96.0%)), viability (25.9 (IQ: 22.2-29.7) vs 25.6 (IQ: 19.7-40.3%)) and acrosome integrity (18.9 (IQ: 5.4-38.9) vs 26.8 (IQ: 0.0-45.2%)) to the same extent in both treated and control aliquots. However, PF treatment before freezing improved the acrosome reaction to ionophore challenge test scores in cryopreserved spermatozoa (9.7 (IQ: 6.6-19.7) vs 4.8 (IQ: 0.5-6.8%); P = 0.002). These data show that pre-freeze treatment of poor quality human sperm with pentoxifylline did not improve post-thaw motility or viability nor did it prevent acrosomal loss during the freeze-thaw process. However, PF, as used, improved the ability of thawed spermatozoa to undergo the acrosome reaction in response to calcium ionophore. The present data indicate that treatment of poor quality human sperm with PF may enhance post-thaw sperm fertilizing ability.

Effects of pentoxifylline treatment before freezing on motility, viability and acrosome status of poor quality human spermatozoa cryopreserved by the liquid nitrogen vapor method

The objective of the present study was to investigate the effects of the direct addition of pentoxifylline (PF) to the ejaculates of men with poor sperm quality before freezing on post-thaw sperm motility, viability, acrosome integrity, and agonist-induced acrosome reaction. Semen specimens from 16 infertile men with impaired sperm count and motility (oligoasthenozoospermia) were divided into two equal aliquots: one received no treatment (control) while the other was incubated with 5 mM PF (treated). Both aliquots were cryopreserved by the liquid nitrogen vapor method. Motility was assessed according to WHO criteria. Acrosome integrity and spontaneous and calcium ionophore-induced acrosome reactions were assessed with fluorescein isothiocyanate-conjugated peanut agglutinin combined with a supra-vital dye (Hoechst-33258). Cryopreservation impaired sperm motility (percentage reduction: 87.4 (interquartile range, IQ: 70.3-92.9) vs 89.1 (IQ: 72.7-96.0 percent)), viability (25.9 (IQ: 22.2-29.7) vs 25.6 (IQ: 19.7-40.3 percent)) and acrosome integrity (18.9 (IQ: 5.4-38.9) vs 26.8 (IQ: 0.0-45.2 percent)) to the same extent in both treated and control aliquots. However, PF treatment before freezing improved the acrosome reaction to ionophore challenge test scores in cryopreserved spermatozoa (9.7 (IQ: 6.6-19.7) vs 4.8 (IQ: 0.5-6.8 percent); P = 0.002). These data show that pre-freeze treatment of poor quality human sperm with pentoxifylline did not improve post-thaw motility or viability nor did it prevent acrosomal loss during the freeze-thaw process. However, PF, as used, improved the ability of thawed spermatozoa to undergo the acrosome reaction in response to calcium ionophore. The present data indicate that treatment of poor quality human sperm with PF may enhance post-thaw sperm fertilizing ability.

Effect of swim-up sperm washing and subsequent capacitation on acrosome status and functional membrane integrity of normal sperm.

OBJECTIVE: Sperm preparation techniques select sperm population with improved sperm motion characteristics. We sought to determine whether the swim-up technique selects spermatozoa with the ability to undergo hypoosmotic swelling, and how swim-up and subsequent capacitation affect the acrosome reaction rate. METHODS: Semen specimens from 15 normal donors were divided into unprocessed, swim-up, and capacitated groups, and sperm motion characteristics, ability to undergo hypoosmotic swelling, and acrosome reaction rate were measured. RESULTS: Sperm motility, viability, and all motion characteristics (except linearity) were significantly increased in both swim-up and capacitated specimens. The ability to respond to hypoosmotic swelling was significantly higher in the spermatozoa isolated by swim-up. The percentage of acrosome-reacted spermatozoa remained unchanged in both unprocessed and swim-up groups, but was significantly higher in the capacitated group. CONCLUSIONS: Swim-up isolates sperm with greater ability to undergo hypoosmotic swelling, but does not change the acrosome reaction rate. In vitro capacitation of spermatozoa selected by swim-up enhances the acrosome reaction rate.

Improvement in motion characteristics and acrosome status in cryopreserved human spermatozoa by swim-up processing before freezing.

The purpose of this study was to examine if selecting a sperm population with improved motion characteristics before freezing reduces the deleterious effects of cryopreservation. Semen specimens from 15 normal donors were divided into two equal aliquots. The first aliquot received no treatment (control), and the second was processed by swim-up from a washed sperm preparation to select a sperm population with better motility and motion characteristics (swim-up). Both aliquots were cryopreserved by the liquid nitrogen vapour method. Percentage motility and motion characteristics were evaluated by computer-assisted semen analysis. Acrosome integrity as well as spontaneous and calcium ionophore-induced acrosome reactions before freezing and after thawing were assessed by fluorescein isothiocyanate conjugated peanut agglutinin combined with a supra vital dye (Hoechst-33258). Swim-up processing enabled selection of a sperm population with better motion characteristics, percentage motility and viability before freezing (P < 0.001), but with no difference in percentage of acrosome-intact spermatozoa (P = 0.63). After thawing, the swim-up specimens exhibited faster velocity and progression than untreated specimens (P < 0.001). They also had higher percentages of spermatozoa with intact acrosomes and spermatozoa able to undergo acrosome reaction in response to calcium ionophore (P < 0.05). Selecting a highly motile sperm population before freezing enhances overall post-thaw spermatozoa quality.

Effect of in vitro incubation on spontaneous acrosome reaction in fresh and cryopreserved human spermatozoa.

OBJECTIVES: Capacitation and acrosome reaction are prerequisites for fertilization. However, in vitro capacitation is not necessary for an agonist-induced acrosome reaction. We studied whether in vitro capacitation is important in spontaneous acrosome reaction and analyzed how capacitation before cryopreservation influences the acrosomal status of thawed spermatozoa. METHODS: Semen specimens from normal donors (n = 15) were processed by the swim-up technique and divided into two aliquots. One aliquot was capacitated (capacitation induced) for three hours by incubation in a modified-BWW medium with 3% HSA at 37 degrees C under 5% carbon dioxide. The other aliquot did not receive any treatment. Both aliquots were analyzed by CASA to assess the capacitation status of the spermatozoa and then cryopreserved. Spontaneous acrosome reaction was assessed by FITC-PNA lectin before and after cryopreservation. Sperm viability was measured using Hoechst-33258 stain. RESULTS: Before freezing, the frequency of spontaneous acrosome reaction was higher in the capacitation-induced sperm preparation (median, 20.5% [interquartile range, 17.2-37.8]) than in swim-up-induced specimens (median, 10.6% [range, 4.8-23.2]; P <.001). The percentage of viable cells showing acrosome reaction increased after cryopreservation in both swim-up-induced specimens (median, 241.4% [interquartile range, 37.1-678.6]; P <.001) and capacitation-induced specimens (median, 48.2% [range, 6.1-63.3]; P = 0.002). Although this increase was higher in the swim-up-induced specimens (P = 0.002), frequency of postthaw spontaneous acrosome reaction was similar in both groups (P = 0.18). CONCLUSIONS: We conclude that sperm capacitation significantly optimizes the acrosome reaction. However, a small proportion of normal spermatozoa do not require capacitation to undergo spontaneous acrosome reaction in vitro. After cryopreservation, the percentage of spermatozoa that had intact acrosomes was similar in both groups, despite the fact that one aliquot underwent prefreeze capacitation. These findings suggest that the acrosome reaction may involve complex mechanism(s) rather than a physiological change induced by capacitation.

Transurethral resection of partially obstructed ejaculatory ducts: seminal parameters and pregnancy outcomes according to the etiology of obstruction.

PURPOSE: We determine how transurethral resection of the ejaculatory ducts performed for infertility affects seminal parameters and pregnancy outcomes in patients with partial ejaculatory duct obstruction due to a congenital or acquired etiological factor. MATERIALS AND METHODS: Based on history and physical examination, hormonal profiles, semen analyses, transrectal ultrasonography and vasography findings partial ejaculatory duct obstruction was diagnosed in 14 men a mean of 30 years old who presented for infertility evaluation. Patients were grouped according to congenital or acquired cause of obstruction. Transurethral resection of the ejaculatory ducts was performed using the standard resectoscope loop technique. Clinical outcome was assessed by postoperative analyses of seminal parameters and pregnancy reports. RESULTS: Transurethral resection of the ejaculatory ducts significantly improved semen quality (ejaculate volume and percentage of sperm motility) in all patients in the congenital group, while all but 1 (83%) had an improved sperm count. Pregnancy was achieved via sexual intercourse by 66% of the patients an average of 5.7 months postoperatively. Of the acquired etiological factor group 37.5% had improved semen quality after transurethral resection of ejaculatory duct and 12.5% achieved pregnancy via sexual intercourse. Postoperative complications occurred at a similar rate in each group (33%). However, complications in the congenital etiology group were minor, while 25% of the men in the acquired group had significant impairment of seminal parameters after transurethral resection of the ejaculatory ducts. CONCLUSIONS: Semen quality improvement and pregnancy outcome after transurethral resection of the ejaculatory ducts for partial ejaculatory duct obstruction differ significantly according to the main etiological cause of obstruction. An equivocal diagnosis of partial obstruction and technical problems during transurethral resection of the ejaculatory ducts may contribute to failure. However, in some cases the reason for failure remains unclear.

Cryopreservation of human spermatozoa with pentoxifylline improves the post-thaw agonist-induced acrosome reaction rate.

Cryopreservation causes extensive damage to spermatozoa, thereby impairing their fertilizing ability. The purpose of this study was to determine if the direct addition of pentoxifylline to the seminal plasma before cryopreservation improved sperm motility and acrosome reaction. Semen specimens from 15 healthy volunteers were divided into two aliquots. One aliquot was treated by adding 5 mM pentoxifylline directly to the seminal plasma (treatment group) and the other aliquot received no treatment (control group). Both aliquots were then cryopreserved by using the liquid nitrogen freezing method. The percentage of motile spermatozoa and various motion characteristics were then evaluated by performing computer-assisted semen analysis. The sperm viability was determined with a supra-vital dye, Hoechst-33258, and the acrosome reaction (spontaneous and calcium ionophore-induced) was monitored using fluorescein isothiocyanate-conjugated peanut lectin (FITC-PNA) binding assays. Pentoxifylline treatment significantly increased the sperm motility, the amplitude of lateral head displacement, the hyperactivation status, and the frequency of spontaneous acrosome reactions before freezing (P < 0.05). After post-thaw, no difference in motion characteristics (except percentage motility) between treated and control groups were observed. Acrosome loss due to the freeze-thaw process was less in the pentoxifylline-treated group (P = 0.0003). In addition, the percentage of cryopreserved acrosome-intact spermatozoa that underwent further acrosome reactions in response to calcium-ionophore challenge was significantly higher in the treated group (P = 0.03). Pentoxifylline treatment before freezing improved the acrosome reaction to ionophore challenge in cryopreserved spermatozoa. Treatment with pentoxifylline appears to minimize sperm damage during the freeze-thaw process and may improve fertilization rates with assisted reproductive procedures such as intrauterine insemination or in-vitro fertilization.

Ureteroscopic stone removal in the distal ureter. Why change?

PURPOSE: We compared our experience with ureteroscopic stone basket manipulation under fluoroscopic guidance to ultrasound ureterolithotripsy for distal ureteral stone removal. MATERIALS AND METHODS: Retrospectively, we analyzed the medical records of 981 patients with ureteral calculi between January 1994 and December 1995, of whom 483 (49%) were treated for stones in the lower ureter and constituted our study group. The decision of when to perform lithotripsy (group 2) versus a basket procedure (group 1) was based on a prospective nonrandomized study and both groups were compared historically. All 322 patients in group 1 (mean age 49 years, range 14 to 86) primarily underwent ureteroscopic stone basket manipulation using the 4-wire Segura* basket. If the calculus could not be removed with the basket and another procedure was necessary, the case was considered a failure. The 161 patients in group 2 (mean age 37 years, range 14 to 74) underwent initially ultrasound ureterolithotripsy for stone fragmentation followed or not by removal of the fragments with the basket. Stone size did not differ significantly between groups 1 (mean 0.9 cm., range 0.6 to 1.7) and 2 (mean 0.8 cm., range 0.7 to 2.0). Ureteroscopy was performed in both groups with epidural anesthesia and on an outpatient basis in the majority of cases. RESULTS: The stone-free rate after 1 procedure was 98.1 and 95.6% in group 1 and 2, respectively. For group 2 versus group 1 the operative time was longer (mean 50, range 25 to 90 versus mean 19 minutes, range 11 to 40, respectively, p < 0.001), the complication rate was greater (16.1 versus 4.3%, respectively, p < 0.001) and average hospital stay was longer (2.1 versus 0.15 day, respectively, p < 0.001). CONCLUSIONS: Ureteroscopic stone treatment with basket manipulation under fluoroscopic guidance or ultrasound ureterolithotripsy provided a high stone-free rate. However, stone removal with the basket manipulation technique should be considered the first choice for treatment of small distal ureteral calculi based on the minimal morbidity, and short operative and recovery times.

Suitability of the hypo-osmotic swelling test for assessing the viability of cryopreserved sperm.

OBJECTIVE: To determine whether the hypo-osmotic swelling test can assess viability of frozen spermatozoa. DESIGN: Fresh semen specimens were divided into two aliquots: one was not processed and the other was processed by swim-up. Both aliquots were then cryopreserved by the liquid nitrogen vapor method. SETTING: Andrology laboratory at a tertiary care facility. PATIENT(S): Eleven volunteers with proven fertility. INTERVENTION(S): The hypo-osmotic swelling test and the sperm viability assessment by Hoechst 33258 (Sigma Chemical Co., St. Louis, MO) and eosin-nigrosin strains were performed in each aliquot. MAIN OUTCOME MEASURE(S): The results of hypo-osmotic swelling test as indicated by swelling of sperm tails were compared with the viability results obtained by Hoechst 33258 stain before freezing and by Hoechst-33258 and eosin-nigrosin stains after freezing. RESULT(S): The hypo-osmotic swelling test and Hoechst 33258 viability results were correlated highly in unprocessed and processed fresh specimens (r = 0.95). After cryopreservation, there was no correlation between hypo-osmotic swelling test and Hoechst 33258 or between hypo-osmotic swelling test and eosin-nigrosin. Prefreeze sperm processing did not influence the post-thaw results. Viability assessed by Hoechst 33258 and eosin-nigrosin was well correlated (r = 0.72). CONCLUSION(S): The hypo-osmotic swelling test can accurately evaluate viability in fresh human spermatozoa but not in cryopreserved ones. Thus, this test cannot be used to select viable cells in cryopreserved samples for assisted reproductive procedures, such as intracytoplasmic sperm injection.

Antegrade endopyelotomy for pelvi-ureteric junction obstruction in children.

OBJECTIVE: To compare the results of repairing pelvi-ureteric junction (PUJ) obstruction by percutaneous endopyelotomy in children with a similar series carried out in adults. PATIENTS AND METHODS: Nine children with primary (six) or secondary (three) PUJ obstruction were treated using a one-stage cold-knife percutaneous endopyelotomy. The success and morbidity rates were compared with a series of 61 adults with primary (46) or secondary (15) PUJ obstruction treated similarly. RESULTS: In children, endopyelotomy was successful in five of six with primary and two of three with secondary PUJ obstruction, with a mean follow-up of 30 months (range 18-56). In the adults, endopyelotomy was successful in 38 of 46 (83%) with primary and 12 of 15 with secondary PUJ obstruction, an overall success rate of 82%, with a mean follow-up of 42 months (range 9-86). There was no statistical difference in the success rates with primary and secondary endopyelotomy between adults and children (P = 0.58). Failures were associated with high-grade hydronephrosis, a stenotic segment > 1.5 cm long and technical problems. Morbidity occurred in one of nine children and 3.2% of the adults. CONCLUSION: This early experience suggests that percutaneous endopyelotomy can be performed safely and successfully in children with primary PUJ obstruction. However, in secondary stenosis, the results were less than optimal. Larger series should be analysed to form definitive conclusions on the role of endopyelotomy for the treatment of PUJ obstruction in children, given the high rate of success of open pyeloplasty and its minimal morbidity.

[High dose rate brachytherapy]. / Braquiterapia de alta taxa de dose.

The high dose rate brachytherapy uses a single source os 192Ir with 10Ci of nominal activity in a remote afterloading machine. This technique allows an outpatient treatment, without the inconveniences of the conventional low dose rate brachytherapy such as use of general anesthesia, rhachianesthesia, prolonged immobilization, and personal exposition to radiation. The radiotherapy department is now studying 5 basic treatment schemes concerning carcinomas of the uterine cervix, endometrium, lung, esophagus and central nervous system tumors. With the Micro Selectron HDR, 257 treatment sessions were done in 90 patients. Mostly were treated with weekly fractions, receiving a total of three to four treatments each. No complications were observed neither during nor after the procedure. Doses, fraction and ideal associations still have to be studied, so that a higher therapeutic ratio can be reached.

Influence of subacute starvation on cardiac response to isoproterenol in rats.

Several studies have reported that the heart is severely affected by chronic malnutrition. However, the influence of these alterations on cardiac function remains unclear. The aim of this study was to evaluate the effects of subacute starvation on the heart chronotropic response to a beta-adrenergic agonist (isoproterenol). Twelve rats were fed rat chow ad libitum or a 50%-restricted diet for 17 days. The rats were killed, the right atrium was isolated and incubated, and in vitro spontaneous cardiac contractions and frequency were registered. Cumulative doses of isoproterenol were added to the solution until maximal cardiac frequency was achieved. A deficit of 25% in the weight gain was observed in study rats compared with controls (92.6 +/- 10.2 vs. 113.8 +/- 19.2 g, p less than 0.05). Mean daily food intake was 4.8 +/- 0.1 and 9.8 +/- 0.5 g/day for semistarved and control rats, respectively. The in vitro cardiac frequency of the semistarved rats was similar to that of controls (290 +/- 15 and 305 +/- 23 beats/min, respectively, NS). However, when isoproterenol was added to the solution, maximal cardiac frequency of the semistarved rats (435 +/- 51 beats/min) was lower than that of control rats (508 +/- 34 beats/min, p less than 0.005). These findings suggest that subacute starvation may alter the cardiac response to beta-adrenergic agonists.