Oesophageal candidiasis in an immunocompetent child

We are reporting a rare case of oesophageal candidiasis in an immunocompetent child secondary to prolonged use of inhaled steroids.

Trampolining as an adjunct to regular physiotherapy in children with cystic fibrosis

Trampolining has become increasingly popular both in the Cystic Fibrosis and general population. In light of the dangers associated with trampolining we surveyed a sample of our outpatient CF population. We found that over half the group questioned used their trampoline on a daily basis, both as a form of exercise and for some as an alternative to physiotherapy. There were no reports of injury that required medical attention. We plan to encourage continued use of trampolines with the introduction of safety guidelines, reinforcing that trampolining is an adjunct to and not a replacement for regular physiotherapy.

Large outbreak of E. coli O157 in 2005, Ireland

In October/November 2005, the largest outbreak of verotoxin-producing Escherichia coli (VTEC) ever recorded in Ireland occurred. Eighteen E. coli O157 culture-positive cases, phage type 32, verotoxin 2 positive, were identified in a small rural area of mid-west Ireland. Half of these patients were asymptomatic. Two children were admitted to hospital with haemolytic uraemic syndrome, one of whom required peritoneal dialysis, and both recovered. All 18 culture-positive patients had indistinguishable or closely related pulsed field gel electrophoresis (PFGE) patterns. Nine of the VTEC O157 culture-positive individuals were in preschool children attending two local crèches. Several culture-positive individuals apparently had exposure to a vulnerable private group water scheme (GWS) in an agricultural area. No microbiological evidence of VTEC was found in food or water. One veterinary sample (an animal rectal swab) was positive for E. coli O157 and the PFGE strain was indistinguishable from the outbreak strain. A case control study showed analytical epidemiological evidence of risk related to potential exposure to the GWS but not related to reported consumption of that water. Selection of cases and controls proved challenging. Transmission occurred primarily in childcare and family settings, with significant person-to-person spread. Control measures included voluntary closure of the crèches, exclusion of culture-positive individuals in risk groups until microbiological clearance was achieved and the issuing of a ‘boil water’ advisory for drinking water pending upgrading of disinfection facilities.

Evaluation of a pen device for self-administration of recombinant human FSH in clomiphene citrate-resistant anovulatory women undergoing ovulation induction

This open-label multicentre study evaluated ease of use, safety, and efficacy of a pen device for self-administration of recombinant follicle-stimulating hormone (rFSH) in 43 subjects undergoing ovulation induction. Follitropin beta was administered subcutaneously with the Follistim Pen within 3 days of onset of menses. A 75 IU starting dose could be increased by 25 or 50 IU on days 8 and 15 if no ovarian response was observed. Human chorionic gonadotrophin (HCG; 10,000 IU) was administered when one follicle > or =18 mm or two to three follicles > or =15 mm were observed. Subjects received standardized instruction for the pen device and subject comprehension was recorded as subjects practised and prepared injections. Ease of use was also evaluated by questionnaire. Forty-four subjects enrolled; 43 were treated with rFSH and 41 were treated with HCG. The comprehension questionnaire revealed that during the mock injection, 100% of subjects properly loaded the cartridge into the pen device, while 95% selected the correct dose and 100% self-injected the medication prescribed. During the second actual injection, 100% of subjects comprehended these pen-related steps. The ease-of-use questionnaire showed that 100% of the subjects rated the overall experience of self-administering with the pen as 'very good' to 'good'. Mean duration and total amount of follitropin beta were 11.4 +/- 4.2 days and 1070.3 +/- 580.3 IU respectively. Ovulation rate was 95%. Biochemical and ongoing pregnancy rates per attempt were 34.9 and 30.2% respectively. Three subjects experienced serious adverse events [asthma; ovarian hyperstimulation syndrome (OHSS) and pain; OHSS]. In conclusion, the pen device provides an easy, safe, and effective way for women to self-administer follitropin beta during ovarian stimulation.

Effect of season and temperature on mortality in amphibians due to chytridiomycosis

OBJECTIVE

To investigate the distribution and incidence of chytridiomycosis in eastern Australian frogs and to examine the effects of temperature on this disease.

DESIGN

A pathological survey and a transmission experiment were conducted.

PROCEDURE

Diagnostic pathology examinations were performed on free-living and captive, ill and dead amphibians collected opportunistically from eastern Australia between October 1993 and December 2000. We conducted a transmission experiment in the laboratory to investigate the effects of temperature: eight great barred frogs (Mixophyes fasciolatus) exposed to zoospores of Batrachochytrium dendrobatidis and six unexposed frogs were housed individually in each of three rooms held at 17 degrees C, 23 degrees C and 27 degrees C.

RESULTS

Chytridiomycosis was the cause of death or morbidity for 133 (55.2%) of 241 free-living amphibians and for 66 (58.4%) of 113 captive amphibians. This disease occurred in 34 amphibian species, was widespread around the eastern seaboard of Australia and affected amphibians in a variety of habitats at high and low altitudes on or between the Great Dividing Range and the coast. The incidence of chytridiomycosis was higher in winter, with 53% of wild frogs from Queensland and New South Wales dying in July and August. Other diseases were much less common and were detected mostly in spring and summer. In experimental infections, lower temperatures enhanced the pathogenicity of B. dendrobatidis in M. fasciolatus. All 16 frogs exposed to B. dendrobatidis at 17 degrees C and 23 degrees C died, whereas 4 of 8 frogs exposed at 27 degrees C survived. However, the time until death for the frogs that died at 27 degrees C was shorter than at the lower temperatures. Infections in survivors were eliminated by 98 days.

CONCLUSION

Chytridiomycosis is a major cause of mortality in free-living and captive amphibians in Australia and mortality rate increases at lower temperatures.

Chromosome banding in Amphibia. XXV. Karyotype evolution and heterochromatin characterization in Australian Mixophyes (Anura, Myobatrachidae)

The mitotic chromosomes of the Australian ground frogs Mixophyes fasciolatus and M. schevilli were analyzed by means of banding techniques and restriction endonuclease digestions. Chromosomal differentiation in these two species occurred exclusively by considerable changes in the amount of telomeric and centromeric heterochromatin, whereas the sizes and locations of interstitial heterochromatic regions, the sizes of all euchromatic segments as well as the positions of centromeres remained nearly identical during karyotype evolution. The major heterochromatic regions in the karyotypes of M. fasciolatus and M. schevilli amount to 30.2% and 20.7%, respectively. They consist of AT base pair-rich repetitive DNA sequences that are brightly labeled by AT-specific fluorochromes and display quenched fluorescence after staining with GC-specific fluorochromes. The heterochromatic regions can be differentiated by treatment of metaphase chromosomes and interphase cell nuclei with various restriction enzymes which either disclose the complete set of C-band patterns in the karyotypes of both species, or else reveal several subsets of these C-bands.

A comparison of sucrose, saline, and saline with egg-yolk diluents on the cryopreservation of cane toad (Bufo marinus) sperm

Previous studies on cane toad (Bufo marinus; Bufonidae; Anura) sperm cryopreservation were extended to compare the effects of cryopreservation in established sucrose (non-ionic) diluents with cryopreservation in ionic diluents containing amphibian Ringer solutions (with and without egg-yolk). In addition, methanol was tested as a cryoprotectant for B. marinus sperm for the first time. Twenty-seven cryoprotective solutions were trialled, with each containing one of the three diluents [10% (w/v) sucrose, simplified amphibian Ringer (SAR) or SAR/egg-yolk], with one of the three cryoprotectants (Me(2)SO, glycerol, or methanol) at one of the three concentrations (10%, 15%, or 20% v/v). Sperm were collected by maceration of testes into cryoprotective solutions with post-thaw recovery assessed as the percentage of motile sperm and the degree (vigour) of motility. Percentage motility was the most sensitive measure of post-thaw recovery. The recovery of motility was lowest in Ringer (SAR) diluents and highest in sucrose diluents, with improved motility in SAR diluents when egg-yolk was added. Methanol was the poorest cryoprotectant and Me(2)SO the most effective. Methanol at high concentrations was shown to support recovery in sucrose diluent but not in SAR, although its effectiveness in SAR was improved by egg-yolk. Overall, the efficacy of diluents in supporting a high percentage of sperm recovery was in declining order: sucrose>SAR/egg-yolk>SAR diluents, and with cryoprotectants: Me(2)SO>glycerol>methanol. In conclusion, SAR offers less potential as a diluent than sucrose, presumably due to the presence of inorganic ions.

Testicular myxosporidiasis in anurans, with a description of Myxobolus fallax n. sp

During studies of amphibian sperm cryopreservation, a new species of myxosporidean parasite (Myxozoa, Myxosporae) was observed in the testes of the Australian dwarf green tree frog Litoria fallax (Peters). Myxosporidiasis was found to have no affect on L. fallax body condition or sperm numbers. Myxobolus spores from L. fallax are morphologically distinct from Myxobolus hylae spores (infecting the sympatric Litoria aurea Lesson) and the three previously named (exotic to Australia) Myxobolus species found in anurans. Myxobolus fallax n. sp. is characterised by: pseudocyst white, spherical to ovoid, 141 x 74 to 438 x 337 microm in diameter (mature); plasmodium with spores loosely arranged within interior. Spores ovoid 13.4 +/- 0.5 (12.6-14.6) microm length, 9.5 +/- 0.4 (8.3-10.6) microm width, 6.8 +/- 0.4 (6.5-7.6) microm depth, 1.4 +/- 0.1 (1.3-1.6) length/width; polar capsules broadly pyriform and equal in size 4.2 +/- 0.3 (3.3-4.7) microm length, 2.4 +/- 0.2 (2.1-2.8) microm width; filament coils 7-8, wound tightly and perpendicular to the longitudinal axis of the capsule; polar filament 34 +/- 7.0 (18-50) microm length; intercapsular appendix and sutural ridge folds absent; and iodinophilous vacuole and mucous envelope lacking. In addition to this new species, data from archival samples of M. hylae are provided which show two morphologically distinct spore types. Both appeared rarely in the same pseudocysts and we cautiously retain the single species.

The effect of saccharides on the post-thaw recovery of cane toad (Bufo marinus) spermatozoa

The effect of monosaccharides (glucose, fructose) and disaccharides (maltose, sucrose, trehalose) as diluents, in cryoprotective additives containing 15% (v/v) DMSO or glycerol as cryoprotectants, were investigated on the recovery of sperm motility after cryopreservation of cane toad (Bufo marinus) spermatoazoa at low (approximately 5 degrees C/min(-1)) and high cooling rates (approximately 35 degrees C/min(-1)). The results show that: 1. recovery of percentage motility was higher with slow cooling than with high cooling rates (37.0 +/- 2.5%, 15.3 +/- 1.6%, P<0.001, respectively), 2. disaccharides were more effective than monosaccharides in protecting spermatozoa with slow cooling (43.9 +/- 1.2%, 26.8 +/- 2.5%, P<0.02, respectively), 3. glycerol was more effective than DMSO with fast cooling (18.3 +/- 2.2%, 12.6 +/- 2.3%, P<0.02, respectively), 4. trehalose with glycerol was the most effective cryoprotective additive with fast cooling (31.0 +/- 3.2%, P<0.05), and 5. overall the recovery of degree (vigour) of motility (range, 1.9 - 3.2) was more resilient to cryopreservation than recovery of percentage motility (range, 8.9 - 51.5 %). Comparison of post-thaw percentage and vigour of sperm motility up to 24 minutes after activation showed disaccharides supported greater duration sperm motility than monosaccharides This result and the recovery of spermatozoa immediately after freeze-thaw, show the main effect of saccharides are as cryoprotectants and not as exogenous energy substrates.

The short-term storage and cryopreservation of spermatozoa from hylid and myobatrachid frogs

The short-term storage (at 0 degrees C) and cryopreservation of spermatozoa may be useful for providing gametes for fertilisations performed in programmes for the conservation and management of endangered amphibians. The current study was undertaken to examine the applicability of amphibian spermatozoa storage protocols developed with the cane toad (Bufo marinus) to a wider range of amphibian species, with a view to ultimately using these protocols for endangered species. In Australia, at least 29 species of recently extinct or endangered frogs are from the families the Myobatrachidae and the Hylidae. This study investigated the applicability of short-term storage and cryopreservation protocols developed for cane toad (Bufo marinus) spermatozoa to those of hylid and myobatrachid species. Storage of spermatozoa in intact testes or in suspensions for six days at 0 degrees C showed spermatozoa maintained higher motility in suspensions than those in testes, and hylid spermatozoa maintained greater motility than myobatrachid spermatozoa. However, the protocols for optimal storage at 0 degrees C varied with testis size when spermatozoa were stored in whole testes. Spermatozoa from 13 frog species representing both families were cryopreserved using sucrose as diluent with Me(2)SO or glycerol as cryoprotectants. After cryopreservation hylid spermatozoa showed a greater recovery than myobatrachid spermatozoa and Me(2)SO provided higher recovery than glycerol. The freeze-thaw recovery of spermatozoa was independent of testes weight of the species studied. These results show spermatozoa from the Hylidae and Myobatrachidae may be stored both in the short-term (at 0 degrees C) and long-term by cryopreservation using protocols established for B. marinus.

Characterization of the biologic activities of a recombinant human zona pellucida protein 3 expressed in human ovarian teratocarcinoma (PA-1) cells

OBJECTIVE

This study was undertaken to clone and express a recombinant human zona pellucida protein 3 and to characterize its biologic activities as a sperm ligand and an inducer of the acrosome reaction.

STUDY DESIGN

Human ovarian teratocarcinoma (PA-1) cells were transfected with an expression vector containing human zona pellucida protein 3 complementary deoxyribonucleic acid with a sequence coding for a 6-histidine tail introduced into its 3' end. Purification of the secreted glycoprotein was performed by sequential affinity (lectin and nickel--nitrilotriacetic acid) and ion-exchange chromatography.

RESULTS

Western blot analysis confirmed a molecular weight of approximately 65 kd for the purified product. A cell-free translation system revealed a correctly sized protein backbone of 47 kd. The recombinant human zona pellucida protein 3 demonstrated specific, potent, and dose-dependent competitive inhibition of sperm-zona pellucida binding in vitro under hemizona assay conditions. Recombinant human zona pellucida protein 3 also stimulated the acrosome reaction of live sperm. This effect was fast, dose dependent, and capacitation time dependent. Furthermore, advance incubation with pertussis toxin, an inactivator of heterotrimeric G proteins, blocked recombinant human zona pellucida protein 3--induced acrosomal exocytosis.

CONCLUSION

The recombinant human zona pellucida protein 3 expressed in PA-1 cells manifested the full spectrum of expected biologic activities. It therefore represents a valuable tool for examination of human fertilization and the design of new strategies in diagnosis of male factor infertility and in contraception.

Short-term storage of cane toad (Bufo marinus) gametes

The responses of cane toad (Bufo marinus) gametes, used as a model for the development of assisted reproduction techniques for rare and endangered amphibians, to short-term storage at temperatures > 0 degrees C were studied. Whole excised testes were stored at 0 degrees or 4 degrees C for 15 days, and sperm motility was measured at excision and after storage for 2, 5, 7, 10, 12 and 15 days. Spermatozoa showed > 50% motility for 7 days at 0 degrees C and for 5 days at 4 degrees C. At 15 days, only spermatozoa stored at 0 degrees C still showed some motility (3%). Sperm suspensions were prepared at 5 day intervals over 30 days in simplified amphibian ringer (SAR) at dilutions of 1:1, 1:5 and 1:10 (w/v) testes:SAR. Aliquots from each dilution were stored at 0 degrees C in Eppendorf tubes opened at 5 day intervals of storage (aerated) or kept sealed (unaerated) (treatments: aerated or unaerated; 5, 10, 15, 20, 25 and 30 days storage). After 30 days, sperm motility and fertilizing capacity were determined. The optimal protocol for sperm storage up to 10 days, as assessed by the retention of fertilizing capacity, was as a 1:5 testis:SAR (w/v) suspension, whereas the longest absolute retention of both motility and fertilizing capacity was observed in concentrated (1:1 dilution), anaerobic suspensions (up to 25-30 days). Oviductal oocytes placed in SAR at 5, 10, 15, 20 and 25 degrees C immediately after ovulation lost viability when cooled rapidly to 5 degrees C and stored for 2 h. However, oocytes retained viability for up to 8 h at the optimum storage temperature of 15 degrees C. Thus, it is concluded that during short-term storage spermatozoa retain viability for longer than oocytes, and that spermatozoa in suspensions retain viability for longer than spermatozoa stored in situ in excised testes.

Local effects of mifepristone on the nonhuman primate endometrium

OBJECTIVE

To determine the effects of a low-dose mifepristone regimen on endometrium in the rhesus monkey by endometrial staging and analysis of molecular markers of endometrial receptivity.

DESIGN

A prospective, randomized comparative study.

SETTING

Academic research environment.

ANIMAL(S)

Normally cycling rhesus (Macaca mulatta) monkeys.

INTERVENTION(S)

Monkeys (5 per control or treatment group) received 0.03 mg of mifepristone in vehicle (sesame oil) per kilogram of body weight or vehicle daily from day 2 of the menstrual cycle to 7 days after the midcycle E2 surge.

MAIN OUTCOME MEASURE(S)

Serum estradiol (E2) and progesterone (P) levels; endometrial staging and immunoreactivity of leukemia inhibitory factor and interleukin-6 performed on fixed endometrial tissues; and relative abundance of endometrial estrogen and P receptor mRNA evaluated with semiquantitative reverse transcriptase polymerase chain reaction in which cyclophilin mRNA, a housekeeping gene product, was coamplified as the reference standard.

RESULT(S)

Mifepristone at 0.03 mg/kg/d induced a delay in the endometrial cycle with a shift from the late to midsecretory phase. This treatment regimen did not suppress the midcycle gonadotropin surge or, presumably, ovulation because P levels were normal during the midluteal phase. The staining intensity of leukemia inhibitory factor and interleukin-6 was dependent upon the endometrial stage and was decreased in treated monkeys. E and P receptor mRNAs increased significantly with mifepristone treatment compared with controls, another indication of delayed uterine staging.

CONCLUSION(S)

Mifepristone at 0.03 mg/kg/d had no antiovulatory effect but delayed development of the endometrium from the late to midsecretory phase. This study provides further evidence that endometrial maturation can be altered without affecting ovarian cyclicity.

Modulation of sperm tail protein tyrosine phosphorylation by pentoxifylline and its correlation with hyperactivated motility

OBJECTIVE

To assess the effect of pentoxifylline on human sperm functions that are crucial to fertilization.

DESIGN

Prospective, controlled study.

SETTING

Academic tertiary care institute.

PATIENT(S)

Healthy male sperm donors.

INTERVENTION(S)

The effects of pentoxifylline (3.6 mM) on hyperactivated motility, sperm binding to the zona pellucida, and sperm protein tyrosine phosphorylation were evaluated.

MAIN OUTCOME MEASURE(S)

Hyperactivated motility was assessed by computer-assisted motion analysis, and tight binding of sperm to homologous zonae pellucidae was examined using the hemizona assay. Sperm protein phosphorylation was evaluated using indirect immunofluorescence with an antibody to phosphotyrosine (PY20).

RESULT(S)

Pentoxifylline significantly stimulated hyperactivated motility at 1 hour and 4 hours; it also significantly increased sperm binding to the zona pellucida and enhanced sperm tail tyrosine phosphorylation at 4 hours under capacitating conditions. There was a statistically significant correlation between hyperactivated motility and sperm tail protein phosphorylation.

CONCLUSION(S)

Pentoxifylline stimulates sperm functions that are essential to achieving fertilization under in vitro conditions in sperm obtained from fertile men. The enhancement of hyperactivated motility is associated with the stimulation of sperm tail tyrosine phosphorylation, suggesting a causal relation and the involvement of a modulatory effect after cyclic adenosine monophosphate-dependent phosphorylation of intermediate proteins.

Genetic evidence for species boundaries in frogs of the Litoria citropa species-group (Anura:Hylidae)

The Litoria citropa species-group comprises several small to medium-sized tree-frog species found from mid-eastern Queensland to eastern Victoria in a variety of habitats along streams associated with the Great Dividing Range. The smaller members of the Litoria citropa species-group, Litoria phyllochroa and L. pearsoniana, have a confused taxonomic history with the taxonomic status of several populations, some regarded as endangered, still in doubt. Multi-locus allozyme electrophoretic profiles and nucleotide sequences of a portion of the mitochondrial 16S ribosomal RNA gene were used to examine the evolutionary relationships of populations that are a geographically comprehensive and morphologically representative sample of the species-group. These data demonstrate the presence of a minimum of three species: L. nudidigitus, L. phyllochroa and a third species whose taxonomic name is yet to be resolved. This third taxon encompasses a wide range of allozyme and mitochondrial nucleotide diversity and can be divided into at least four evolutionarily significant units (ESUs) that replace each other in a linear sequence from north of the Hunter Valley in New South Wales to the Kroombit Tops in central Queensland. A possible zone of hybridisation between the southernmost pair of these ESUs was identified in northern New South Wales. The fourth ESU, a northern outlier of the range of the species-group, is confined to Kroombit Tops, central Queensland.While its phylogenetic relationship with the other three ESUs was not resolved precisely by the present analysis, it nevertheless comprises a distinct and very divergent mitochondrial lineage of considerable antiquity.Resolution of the status of a further name applied to the species-group, L. piperata, awaits a morphological analysis that includes the relevant type material.

Pentoxifylline stimulates various sperm motion parameters and cervical mucus penetrability in patients with asthenozoospermia

Pentoxifylline (PTX) was incubated in vitro with human spermatozoa to examine its effects on sperm motility characteristics and bovine cervical mucus penetrability (BCMP). Sperm motion parameters were assessed by computer-assisted motion analysis (CASA) using HTM-IVOS and BCMP was evaluated using the Penetrak kit. In vitro incubation with PTX (1 mg ml-1; 3.6 mM, 30 min) did not significantly change percentage motility, average path velocity (VAP), straight-line velocity (VSL) or beat cross frequency (BCF) of spermatozoa from normozoospermic or asthenozoospermic samples. However, it significantly increased curvilinear velocity (VCL), amplitude of lateral head displacement (ALH) and hyperactivated motility (HA), and significantly decreased linearity (LIN) of spermatozoa from both samples. Pentoxifylline was found to increase BCMP scores for spermatozoa from asthenozoospermic samples, but did not affect scores for spermatozoa from normozoospermic samples. Bovine cervical mucus penetrability (BCMP) was found to be positively and significantly correlated with the percentage motility of both non-PTX-treated and PTX-treated spermatozoa for asthenozoospermic samples. These results demonstrated that PTX enhanced several motion sperm parameters as well as BCMP in asthenozoospermic samples and suggest a potential use of the methylxanthine in infertile patients with motility defects undergoing artificial insemination.

Successful recovery of motility and fertility of cryopreserved cane toad (Bufo marinus) sperm

The recent decline and extinction of amphibian species is a worldwide phenomenon without an identified cause or solution. Assisted reproductive technologies, including sperm cryopreservation, are required to manage endangered amphibian species and preserve their genetic diversity. This study on the Anuran amphibian (Bufo marinus) was undertaken to determine the feasibility of cryopreservation of amphibian sperm. Sperm suspensions for cryopreservation were prepared by macerating testes in cryoprotective additives of 10% (w/v) sucrose or 10% (w/v) sucrose containing either 10, 15, or 20% (v/v) glycerol or 10, 15, or 20% (v/v) dimethyl sulfoxide (Me2SO). Suspensions were then cooled to -85 degreesC using a controlled rate cooler, stored in LN2, and thawed in air. The motility and fertilization rate of cryopreserved suspensions and unfrozen control suspensions in Simplified Amphibian Ringer were compared. Sucrose alone had no cryoprotective effect. All other treatments showed varying degrees of recovery of motility and fertilizing capacity. High rates of recovery of motility and fertilizing capacity were observed with 15% Me2SO (68.9 +/- 3.8 and 60.5 +/- 4.7%) and 20% glycerol (58.0 +/- 5.9 and 81.4 +/- 4.3%), respectively. Motility and fertilization rates were similar with Me2SO but diverged with glycerol as cryoprotectant. The data demonstrate the feasibility of using sperm cryopreservation with amphibian species. Copyright 1998 Academic Press.

Increase of intracellular calcium is not a cause of pentoxifylline-induced hyperactivated motility or acrosome reaction in human sperm

OBJECTIVE

To investigate the effects of the phosphodiesterase inhibitor pentoxifylline on hyperactivated motility and acrosome reaction in human sperm and to determine whether its stimulatory effects occur via increased intracellular calcium levels.

DESIGN

Prospective study.

SETTING

Academic tertiary care facility.

PARTICIPANT(S)

Healthy male donors.

INTERVENTION(S)

The effects of pentoxifylline on hyperactivated motility, acrosome reaction, and intracellular calcium were studied and compared with the effects of progesterone. Thapsigargin, a known mobilizer of intracellular calcium, also was used as positive control.

MAIN OUTCOME MEASURE(S)

Hyperactivated motility was assessed by computer-assisted sperm motion analysis using the HTM-IVOS, acrosome reaction was evaluated with the fluorescent probe fluorescein isothiocyanate-labeled Pisum sativum agglutinin, and intracellular calcium was determined by fura-2 using spectrofluorometry.

RESULT(S)

Pentoxifylline significantly increased both hyperactivated motility and acrosome reaction. Enhancement of hyperactivated motility by pentoxifylline in the capacitation medium persisted for up to 5 hours after pentoxifylline was washed from the medium. It also enhanced the percentage of acrosome-reacted spermatozoa after 4 hours of incubation. These effects occurred in the presence of a marginally significant decrease in intracellular calcium.

CONCLUSION(S)

Pentoxifylline stimulates hyperactivated motility and acrosome reaction in spermatozoa from fertile men. Its stimulatory effects occur through mechanism(s) other than increase in intracellular calcium.

Shaker-1 mutations reveal roles for myosin VIIA in both development and function of cochlear hair cells

The mouse shaker-1 locus, Myo7a, encodes myosin VIIA and mutations in the orthologous gene in humans cause Usher syndrome type 1B or non-syndromic deafness. Myo7a is expressed very early in sensory hair cell development in the inner ear. We describe the effects of three mutations on cochlear hair cell development and function. In the Myo7a816SB and Myo7a6J mutants, stereocilia grow and form rows of graded heights as normal, but the bundles become progressively more disorganised. Most of these mutants show no gross electrophysiological responses, but some did show evidence of hair cell depolarisation despite the disorganisation of their bundles. In contrast, the original shaker-1 mutants, Myo7ash1, had normal early development of stereocilia bundles, but still showed abnormal cochlear responses. These findings suggest that myosin VIIA is required for normal stereocilia bundle organisation and has a role in the function of cochlear hair cells.

Clinical significance of human sperm-zona pellucida binding

OBJECTIVE

To assess the relationship between sperm morphology and motion parameters and sperm-zona pellucida (ZP) binding capacity under hemizona assay (HZA) conditions and to determine the discriminatory power of the HZA for the prediction of in vitro sperm fertilizing ability.

DESIGN

Prospectively designed study.

SETTING

Academic tertiary centers.

PATIENT(S)

One hundred ninety-six couples undergoing IVF therapy participated in this study.

INTERVENTION(S)

Hemizona assay and IVF results were determined for each couple.

MAIN OUTCOME MEASURE(S)

Computerized sperm motion analysis, sperm morphology (strict) criteria), and HZA results were correlated with fertilization outcome.

RESULT(S)

Among sperm parameters from the original ejaculates, morphology was the best predictor of sperm-ZP binding ability; hyperactivated motility was the best predictor of HZA results after swim-up separation of the motile sperm fractions. The HZA index provided the highest discriminatory power for fertilization success/failure, with an overall accuracy of 86%.

CONCLUSION(S)

Sperm morphology and hyperactivated motility showed a high correlation with the capacity of sperm to achieve tight binding to the ZP. The excellent positive and negative predictive values of the HZA for fertilization outcome provide additional support for the use of this functional bioassay in the decision-making process within the assisted reproduction setting.

Unravelling the genetics of deafness

Hearing-impaired mouse mutants not only are good models for human hereditary deafness, but also are extremely useful for understanding the molecular basis of the cochlear defect. We describe here how we identified the gene responsible for the deafness and vestibular defects in the shaker-1 mouse mutant as a myosin VII gene. Three different mutations, all causing the same phenotype in different lines of mouse, were found, providing good evidence that we had, indeed, found the correct gene. The same gene was subsequently found to be involved in Usher's syndrome type 1B, which features deafness, vestibular dysfunction, and progressive retinitis pigmentosa. The myosin VII gene is expressed in sensory hair cells, but not in supporting cells or neurons. We are investigating the role of myosin VII in hair cell development and function. Analysis of the different mutant stocks suggests it has at least two functions. First it is involved in the development and maintenance of the stereocilia bundle. Second, it has a role in inner hair cell function. No evidence of retinal degeneration like that in Usher's syndrome has been found in the shaker-1 mutants so far studied. The benefits of understanding the function of the gene for families with Usher's type 1B are discussed. This gene is the first to be identified as causing the most common type of disorder in human hearing impairment, neuroepithelial abnormalities, and suggests a new class of candidate genes for involvement in such defects.

The effect of coculture on the postfertilization development of in vitro-matured monkey oocytes

OBJECTIVE

To determine if the developmental potential of embryos resulting from in vivo- and in vitro-matured monkey oocytes could be increased through the use of a coculture system.

DESIGN

Randomized prospective comparison of embryos resulting from either in vitro- or in vivo-matured oocytes cocultured with Vero cells or cultured in medium alone (control).

SETTING

Basic research laboratory.

MAIN OUTCOME MEASURES

In vitro embryo development to the blastocyst stage and blastocyst hatching.

RESULTS

No significant difference in development was noted between coculture and control groups with embryos resulting from in vivo-matured oocytes. However, coculture was found to improve significantly the development of monkey embryos resulting from in vitro-matured oocytes.

CONCLUSIONS

These results demonstrate that primate embryos resulting from in vitro-matured and in vitro-fertilized oocytes differ in their culture requirement when compared with embryos resulting from in vivo-matured oocytes.

Effects of hydrogen peroxide on human spermatozoa

PURPOSE

Reactive oxygen species (ROS) have been reported widely to cause deleterious effects on sperm viability and function due to peroxidation of membrane lipids. However, their action appears more selective at low concentrations; recent evidence indicates that the superoxide anion can promote capacitation and induce hyperactivated motility (HA) in human spermatozoa and that hydrogen peroxide (H2O2) may participate in capacitation of hamster spermatozoa. The objective of these studies was to investigate the direct effects of H2O2 on functions crucial to fertilization in human spermatozoa.

METHODS

In these prospective studies, we examined the dose- and time-dependent effects of H2O2 on sperm membrane-mediated events (binding to the zona pellucida and changes in intracellular calcium concentration [Ca2+]i, motility patterns, and acrosome reaction). Sperm from fertile donors were used in the experiments under capacitating conditions after separation of the motile fraction by wash/swim-up. [Ca2+]i was measured by the fluorescent fura-2 indicator, and sperm-zona pellucida binding was assessed with the hemizona assay (HZA). Hyperactivated motility was evaluated by computerized analysis, and the percentage of acrosome reacted sperm was detected by FITC-Pisum sativum lectin and indirect immunofluorescence.

RESULTS

In the HZA, H2O2 did not influence sperm-zona pellucida binding at low concentrations (0.05 mM and 0.1 mM), but significantly reduced binding at 0.2 mM (P < 0.004 vs controls). H2O2 significantly decreased HA in a dose-dependent manner (P < 0.0001) and had a significant effect (P < 0.01) on acrosome reaction (stimulatory effect at 0.01 mM). H2O2 did not affect basal [Ca2+]i; however, H2O2 (0.1 mM through 10 mM) decreased the initial phase of progesterone-induced (P4: 1 microM) enhancement of [Ca2+]i in a dose- and time-dependent fashion. Preincubation of sperm with catalase (20 micrograms/ml) potentiated the P4-induced increase of [Ca2+]i. H2O2 did not significantly modify [Ca2+]i increase in response to inomycin (10 microM).

CONCLUSIONS

These experiments show that H2O2 directly affects sperm functions crucial to fertilization in a dose- and time-dependent fashion. Low concentrations maintain capacitation, whereas higher concentrations have deleterious effects, as determined by the end points of the capacitation process. The latter effects are probably dependent on modifications of plasma membrane and intracellular homeostasis by the oxidative process.

A sequential analysis of the effect of progesterone on specific sperm functions crucial to fertilization in vitro in infertile patients

The objective of these studies was to evaluate the modulatory effect(s) of progesterone on sperm functions crucial to fertilization in infertile men with abnormal sperm parameters. A prospective, controlled study applying a sequential diagnostic analysis capable of identifying specific dysfunctions of the male gamete was performed. Patients (n = 14) were allocated to the study group if they had a history of infertility of > 1 year duration and after semen evaluation showed teratozoospermia (< 14% normal sperm forms as diagnosed by strict criteria) or terato-asthenozoospermia (< 50% progressive motility). After swim-up separation of the motile sperm fraction, the following functions were assessed with and without previous exposure to progesterone (1.0 micrograms/ml): acrosome reaction (using Pisum sativum agglutinin), hyperactivated motility (using a computerized semen analyser), sperm-zona pellucida binding (in the hemizona assay), sperm-zona pellucida penetration (in a sperm-zona penetration assay), and sperm-oocyte penetration (using the hamster zona-free oocyte/sperm penetration assay). Progesterone did not affect the percentage of acrosome-reacted spermatozoa after 1 or 3 h of incubation. Hyperactivated motility was significantly enhanced by progesterone after 1 h (12 +/- 4 versus 6 +/- 2% in controls; P < 0.02). Although progesterone did not affect sperm-zona binding, it significantly enhanced both sperm-zona pellucida penetration (27 versus 12% in controls; P = 0.03) and sperm-oocyte penetration (15 versus 8% in controls; P < 0.05). Because those sperm functions enhanced by progesterone are crucial to fertilization, the steroid may have value in the treatment of some male-factor patients undergoing assisted reproductive therapy.

Effect of progesterone on human zona pellucida sperm binding and oocyte penetrating capacity

OBJECTIVE

To determine if sperm exposure to P produces an enhancement in its fertilizing capacity.

DESIGN

Sperm from fertile donors were exposed to P at 0.1 and 1.0 microgram/mL for 1 or 24 hours. The effects on hyperactivated (HA) motility at 1 and 4 hours, acrosome reaction (as determined by Pisum sativum agglutinin or T6/antibody techniques), on human zona pellucida binding (by using the hemizona assay), and on the penetrating ability (by using the zona-free hamster ova assay) were evaluated.

RESULTS

Exposure to P at 1.0 microgram/mL enhanced HA motility after 1 and 4 hours of P exposure, the acrosome reaction after 24 hours' incubation, the number of sperm bound/hemizona after 1-hour incubation, and the penetration rates in the hamster ova assay at both incubation intervals.

CONCLUSION

Sperm exposure to P enhances its fertilizing capacity in fertile men, and further investigation is warranted as a possible treatment for male factor patients.

Hemizona assay (HZA) demonstrates effects of characterized mouse antihuman sperm antibodies on sperm zona binding

Characterized antihuman sperm monoclonal antibodies from mice were evaluated using the hemizona assay (HZA) to determine whether sperm:zona binding was effected. The seven monoclonal antibodies were characterized using human sperm in agglutination, immobilization, and penetration assays. Semen was provided by four fertile men and used in the HZA to determine if the presence of a monoclonal antibody would affect tight binding of the sperm to the zona pellucida. Pre-incubation of MA-14 for 1 h with the sperm induced a 33-54% reduction of the number of tightly bound sperm. This antibody reacts to an antigen located on the acrosome and midpiece. Experiments in which there was no pre-incubation of the antibody with sperm, resulted in no significant reduction in the number of sperm bound in the HZA. These findings suggest that an anti-human sperm antibody produced in mice can modulate sperm:zona binding. Reduction in zona binding could indicate a cause of immune-related infertility and this test may be useful in selecting an antigen for contraceptive vaccine development.

Mouse monoclonal antibodies against human sperm: evidence for immunodominant glycosylated antigenic sites

Thirty mouse monoclonal antibodies (MoAbs) raised against human sperm detect common antigenic determinants on human lymphocytes, erythrocytes, bacteria and endotoxin. Specific chemical, enzymatic and lectin blocking studies indicate that the sperm-associated antigens defined by these MoAbs are glycoconjugates. Further studies including reactivity of these MoAbs with organic sperm extracts indicate that the predominant carriers of these carbohydrate antigens are glycolipids and that the terminal immunodominant monosaccharide may be N-acetyl-glucosamine or N-acetylgalactosamine.