Hearing Evaluation of ARthroplasty Surgeons: results from the HEARS study.

AIMS: The aim of this study was to investigate whether the prevalence of hearing loss among arthroplasty surgeons was comparable to clinicians from other medical specialties and to explore the factors associated with hearing loss. METHODS: A cross-sectional prevalence study was carried out. Arthroplasty surgeons and non-surgical clinicians were recruited from orthopaedic and medical conferences. All participants were given a paper questionnaire including demographic details, hearing history and the Tinnitus and Hearing Survey. All participants were screened for hearing loss in a quiet room using the HearCheck Screener™ (HCS; Siemens, Munich, Germany). Logistic regression was used to identify factors associated with hearing loss. All statistical models were adjusted for age, gender, smoking status and personal noise exposure. RESULTS: The HEARS (Hearing Evaluation of ARthroplasty Surgeons) study recruited 188 participants (106 arthroplasty surgeons; 82 non-surgical clinicians). Prevalence of hearing loss identified by the HCS was 31% for arthroplasty surgeons vs 11% for non-surgical clinicians. The odds of failing the HCS were 3.7 times higher in arthroplasty surgeons compared to their non-surgical colleagues (p < 0.004). The odds of self-reported hearing using the Tinnitus and Hearing Survey were 2.79 times higher among arthroplasty surgeons (p < 0.003). CONCLUSION: The prevalence of hearing loss among arthroplasty surgeons is significantly higher than in their non-surgical colleagues. Noise generated during arthroplasty surgery should be recognised and managed to create safer working conditions.

Phosphorylation of the WH2 domain in yeast Las17/WASP regulates G-actin binding and protein function during endocytosis.

Actin nucleation is the key rate limiting step in the process of actin polymerization, and tight regulation of this process is critical to ensure actin filaments form only at specific times and at defined regions of the cell. WH2 domains are short sequence motifs found in many different actin binding proteins including WASP family proteins which regulate the actin nucleating complex Arp2/3. In this study we reveal a phosphorylation site, Serine 554, within the WH2 domain of the yeast WASP homologue Las17. Both phosphorylation and a phospho-mimetic mutation reduce actin monomer binding affinity while an alanine mutation, generated to mimic the non-phosphorylated state, increases actin binding affinity. The effect of these mutations on the Las17-dependent process of endocytosis in vivo was analysed and leads us to propose that switching of Las17 phosphorylation states may allow progression through distinct phases of endocytosis from site assembly through to the final scission stage. While the study is focused on Las17, the sole WASP family protein in yeast, our results have broad implications for our understanding of how a key residue in this conserved motif can underpin the many different actin regulatory roles with which WH2 domains have been associated.

Elevated CDCP1 predicts poor patient outcome and mediates ovarian clear cell carcinoma by promoting tumor spheroid formation, cell migration and chemoresistance.

Hematogenous metastases are rarely present at diagnosis of ovarian clear cell carcinoma (OCC). Instead dissemination of these tumors is characteristically via direct extension of the primary tumor into nearby organs and the spread of exfoliated tumor cells throughout the peritoneum, initially via the peritoneal fluid, and later via ascites that accumulates as a result of disruption of the lymphatic system. The molecular mechanisms orchestrating these processes are uncertain. In particular, the signaling pathways used by malignant cells to survive the stresses of anchorage-free growth in peritoneal fluid and ascites, and to colonize remote sites, are poorly defined. We demonstrate that the transmembrane glycoprotein CUB-domain-containing protein 1 (CDCP1) has important and inhibitable roles in these processes. In vitro assays indicate that CDCP1 mediates formation and survival of OCC spheroids, as well as cell migration and chemoresistance. Disruption of CDCP1 via silencing and antibody-mediated inhibition markedly reduce the ability of TOV21G OCC cells to form intraperitoneal tumors and induce accumulation of ascites in mice. Mechanistically our data suggest that CDCP1 effects are mediated via a novel mechanism of protein kinase B (Akt) activation. Immunohistochemical analysis also suggested that CDCP1 is functionally important in OCC, with its expression elevated in 90% of 198 OCC tumors and increased CDCP1 expression correlating with poor patient disease-free and overall survival. This analysis also showed that CDCP1 is largely restricted to the surface of malignant cells where it is accessible to therapeutic antibodies. Importantly, antibody-mediated blockade of CDCP1 in vivo significantly increased the anti-tumor efficacy of carboplatin, the chemotherapy most commonly used to treat OCC. In summary, our data indicate that CDCP1 is important in the progression of OCC and that targeting pathways mediated by this protein may be useful for the management of OCC, potentially in combination with chemotherapies and agents targeting the Akt pathway.

Novel PCR assay for determining the genetic sex of mice.

A number of studies require the determination of the genetic sex of mouse embryos before sexual differentiation and/or of mutant mice that display partial or complete sex reversal. The majority of current methods for sexing by PCR involve multiplexing of 2 primer pairs. We have developed a novel sexing PCR using a single primer pair that amplifies fragments from the X and the Y chromosome with a clear size difference between the respective amplicons. This assay provides a rapid and reliable method to identify the genetic sex of mice across different mouse strains.

Small bowel perforation following capsule endoscopy: a case report.

Small bowel perforation following a capsule endoscopy (CE) is a rare but dreadful complication. We report a CE induced small bowel perforation in a patient with Crohn's disease where preoperative investigations failed to reveal any strictures.

Testicular germ cell tumours in dogs are predominantly of spermatocytic seminoma type and are frequently associated with somatic cell tumours.

Unlike seminomas in humans, seminomas in animals are not typically sub-classified as classical or spermatocytic types. To compare testicular germ cell tumours (TGCT) in dogs with those of men, archived tissues from 347 cases of canine testicular tumours were morphologically evaluated and characterized using human classification criteria. Histopathological and immunohistological analysis of PLAP, KIT, DAZ and DMRT1 expression revealed that canine seminomas closely resemble human spermatocytic seminomas. In addition, a relatively frequent concomitant presence of somatic cell tumours was noted in canine TGCT. None of the canine TGCT evaluated demonstrated the presence of carcinoma in situ cells, a standard feature of human classical seminomas, suggesting that classical seminomas either do not occur in dogs or are rare in occurrence. Canine spermatocytic seminomas may provide a useful model for this rare human neoplasm.

The role of surface charge and hydrophobicity in the attachment of Anoxybacillus flavithermus isolated from milk powder.

The aim of the present study was to investigate the attachment mechanisms that enable the thermophile Anoxybacillus flavithermus (B12) to attach to stainless-steel surfaces. Passing a B12 culture through a column of stainless-steel chips, collecting the first cells to pass through, re-culturing, and repeating the process six times, resulted in the isolation of a mutant, labeled X7, with tenfold reduced ability to attach to stainless steel as well as a reduced ability to attach to plastic. A comparison of bacterial cell-surface properties indicated that X7 was less hydrophobic than its parental strain B12. Cell-surface charge measurements also suggest that X7 had a lower net-negative surface charge. Disruption of extracellular polysaccharides and DNA appeared to have no effect on the attachment process. Removal of surface proteins caused a reduction in attachment of both B12 and X7, suggesting surface protein involvement in attachment.

Prenatal exposure to vinclozolin disrupts selective aspects of the gonadotrophin-releasing hormone neuronal system of the rabbit.

Developmental exposure to the agricultural fungicide vinclozolin can impair reproductive function in male rabbits and was previously found to decrease the number of immunoreactive-gonadotrophin-releasing hormone (GnRH) neurones in the region of the organum vasculosum of the lamina terminalis and rostral preoptic area by postnatal week (PNW) 6. In the present study, in an aim to further examine the disruption of GnRH neurones by foetal vinclozolin exposure, pregnant rabbits were dosed orally with vinclozolin, flutamide or carrot paste vehicle for the last 2 weeks of gestation. Offspring were euthanised at birth (males and females), PNW 6 (females), PNW 26 (adult males) or PNW 30 (adult females) of age. At birth and in adults, brains were sectioned and processed for immunoreactive GnRH. The numbers of immunoreactive GnRH neuronal perikarya were significantly decreased in vinclozolin-treated rabbits at birth and in adult littermates. By contrast, there was an increase in GnRH immunoreactivity in the terminals in the region of the median eminence. Analysis of PNW 6 female brains by radioimmunoassay revealed a two-fold increase in GnRH peptide content in the mediobasal hypothalamus in vinclozolin-treated rabbits. This finding was complemented by immunofluorescence analyses, which revealed a 2.8-fold increase in GnRH immunoreactivity in the median eminence of vinclozolin compared to vehicle-treated females at PNW 30. However, there was no difference between treatment groups in the measures of reproduction that were evaluated: ejaculation latency, conception rates or litter size. These results indicate that sub-acute, prenatal vinclozolin treatment is sufficient to create perdurable alterations in the GnRH neuronal network that forms an important input into the reproductive axis. Finally, the effect of vinclozolin on the GnRH neuronal network was not comparable to that of flutamide, suggesting that vinclozolin was not acting through anti-androgenic mechanisms.

Chronic exposure to low levels of dibromoacetic acid, a water disinfection by-product, adversely affects reproductive function in male rabbits.

Four groups (minimum of 10/dose group) of male Dutch-belted rabbits were treated daily with dibromoacetic acid (DBA) via drinking water beginning in utero from gestation day 15 to adulthood; target dosages were 1, 5, and 50 mg DBA/kg body weight. Developmental, prepubertal as well as postpubertal reproductive sequelae were evaluated. One (out of 22), 2 (out of 32), and 1 (out of 21) male offspring in the 1, 5, and 50 mg DBA/kg groups were unilaterally cryptorchid. There were no significant differences in serum follicle-stimulating hormone, luteinizing hormone, and testosterone (basal concentrations or in response to exogenous gonadotropin-releasing hormone) in both prepubertal and adult rabbits. Chronic exposure to DBA adversely affected the mating abilities of some rabbits. The number of sperm produced was not affected, but spermiogenesis was disrupted, resulting in unique sperm acrosomal-nuclear malformations even at the 1-mg dose level. Concentrations of SP22, a specific sperm membrane fertility protein, in detergent extracts of ejaculated sperm were significantly lower (P < .05) in all DBA-treated groups compared with controls. The conception rates following artificial insemination of a constant number of sperm for 1, 5, and 50 mg DBA/kg groups were 55% (10/18), 65% (13/20), and 55% (9/16), respectively, vs 85% (17/20) for control group. Histologic lesions in testes characterized by spermatogenic arrest predominantly at the round spermatid stage, pyknosis of differentiating germ cells, and ultimate degeneration and desquamation leaving focal vacuolation in seminiferous epithelium were evident in DBA-treated groups. Thus, male rabbits exhibit reproductive toxicity with exposure to DBA during reproductive development at dosages as low as 1 mg/kg body weight.

Sequelae in male rabbits following developmental exposure to p,p'-DDT or a mixture of p,p'-DDT and vinclozolin: cryptorchidism, germ cell atypia, and sexual dysfunction.

Rabbit does (7-9 per group) were treated daily per orum from gestation day 15 through post-natal week 4 to provide per kg body wt 25 micaromol (low) or 250 micromol (high) p,p'-DDT or a mixture of DDT and vinclozolin (12.5 and 125 micromol each). Developmental as well as post-pubertal reproductive sequelae of male progeny were studied. Testicular descent in some pups was impaired by DDT. Serum LH or testosterone was not affected. FSH was lower in mixture- but not in DDT-exposed rabbits. Lack of sexual interest, penile erection and ejaculation were observed in some mixture rabbits. Sperm counts were unaffected, but morphologically normal spermatozoa were fewer; nuclear and acrosomal morphogenesis was disrupted. Atypical germ cells resembling carcinoma in situ were found. Also considering data for vinclozolin [Veeramachaneni DNR, Palmer JS, Amann RP, Kane CM, Higuchi TT, Pau K-YF. Disruption of sexual function, FSH secretion, and spermiogenesis in rabbits following developmental exposure to vinclozolin, a fungicide. Reproduction 2006;131:805-16], we concluded that DDT causes cryptorchidism and germ cell atypia, vinclozolin permanently disrupts FSH secretion and sexual function, and the mixture causes the full spectrum of dysgenesis.

Congenital genitourinary anomalies and sexual function.

Congenital urologic abnormalities in males may contribute to sexual dysfunction seen in young men. It is the purpose of this paper to review some of the more common congenital urologic anomalies and their impact on sexual and reproductive function.

Disruption of sexual function, FSH secretion, and spermiogenesis in rabbits following developmental exposure to vinclozolin, a fungicide.

We studied sequelae of prenatal plus infantile exposure of male rabbits to vinclozolin, because it is ingested by women and children. Female Dutch-Belted rabbits (7-10/group) were treated daily per orum from gestation day 15 through post-natal week 4 to provide 0, 7.2, or 72 mg vinclozolin/kg dam's body weight/day. Vinclozolin had no effect on maintenance of pregnancy, growth of pups, age at testicular descent or weight of organs. Concentrations of serum LH or testosterone at 6, 12, or 24 weeks of age were unaffected. However, FSH was lower (P < 0.05) in both vinclozolin groups at all three ages. Following injection of GnRH at 12 or 24 weeks, the increase in FSH was less (P < 0.05) in both vinclozolin groups, as was testosterone at 12 weeks of age. After full sexual maturity, 2 of 7 low dose rabbits were uninterested in female or male teasers and never achieved erection or ejaculation. Overall, rates of ejaculation failure were: control 0% (0/48), low dose 29% (12/42), and high dose 5% (3/60). Daily sperm production per gram of testis and total number of sperm per ejaculate in both vinclozolin groups were similar (P > 0.1) to controls. However, semen from vinclozolin rabbits contained over two times more (P < 0.05) morphologically abnormal spermatozoa, mostly nuclear and acrosomal defects, than semen from controls. Seminiferous tubules with degenerative changes were more frequent (P < 0.05) in vinclozolin rabbits than in controls. Lesions included syncytia of spherical spermatids and desquamation of germ cells. Hence, developmental exposure to vinclozolin caused presumably permanent changes in copulatory ability, secretion of FSH, and spermiogenesis.

G551D CF mice display an abnormal host response and have impaired clearance of Pseudomonas lung disease.

Several cystic fibrosis (CF) mouse models demonstrate an increased susceptibility to Pseudomonas aeruginosa lung infection, characterized by excessive inflammation and high rates of mortality. Here we developed a model of chronic P. aeruginosa lung disease in mice homozygous for the murine CF transmembrane conductance regulator G551D mutation that provides an excellent model for CF lung disease. After 3 days of infection with mucoid P. aeruginosa entrapped in agar beads, the G551D animals lost substantially more body weight than non-CF control animals and were less able to control the infection, harboring over 40-fold more bacteria in the lung. The airways of infected G551D animals contained altered concentrations of the inflammatory mediators tumor necrosis factor-alpha, KC/N51, and macrophage inflammatory protein-2 during the first 2 days of infection, suggesting that an ineffective inflammatory response is partly responsible for the clearance defect.

Factors influencing attachment of thermophilic bacilli to stainless steel.

AIMS: This project aimed to investigate the mechanism of attachment of the vegetative cells and spores of thermophilic bacilli to stainless steel with a view to devising strategies to limit biofilm development and survival. METHODS AND RESULTS: Spores and vegetative cells of bacterial isolates were exposed to protein denaturing agents (sodium dodecyl sulphate (SDS) and trypsin) and polysaccharide removing agents (sodium metaperiodate, trichloroacetic acid (TCA) and lysozyme). Treatment with sodium metaperiodate, TCA and lysozyme increased the number of vegetative cells attaching in many of the strains studied, while SDS and trypsin decreased attachment. Spores attached to stainless steel in greater numbers than vegetative cells, and the various treatments had less effect on this attachment than for vegetative cells. Viability of the cells or spores was not an important factor in attachment, as cells and spores rendered non-viable also attached to stainless steel in similar numbers. Coating the stainless steel with skim milk proteins decreased the attachment of both vegetative cells and spores. There was no correlation between the degree of attachment and the amount of extracellular polysaccharide (EPS) produced by each strain, surface hydrophobicity or zeta potential of vegetative cells or spores, though spores were found to be more hydrophobic than vegetative cells. CONCLUSIONS: The results suggest that biofilm formation by these thermophilic bacilli is probably a multifactorial process, and that cell-surface proteins play a very important role in the initial process of attachment during the formation of biofilms by these bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: This information will provide direction for developing improved cleaning systems to control biofilms of thermophilic bacilli in dairy manufacturing plants.

Long-term effects on male reproduction of early exposure to common chemical contaminants in drinking water.

We evaluated sequelae to early exposure of male rabbits to drinking water containing chemicals typical of ground water near hazardous waste sites. The mixture (p.p.m. at 1x) was 7.75 arsenic, 1.75 chromium, 9.25 lead, 12.5 benzene, 3.75 chloroform, 8.5 phenol and 9.5 trichloroethylene. Dutch-Belted does received mixture at 0x (deionized water; control), 1x or 3x as drinking water from day 20 pregnancy through weaning. Exposure of individual males (7-9/treatment) continued until 15 weeks (adolescence); then, all males received deionized water. At 57-61 weeks of age, ejaculatory capability and seminal, testicular, epididymal and endocrine characteristics were evaluated. At 10 opportunities with a female teaser, all seven control males ejaculated every time, but 12 of the 17 treated males failed to express interest, achieve erection and/or ejaculate on one to five occasions; four of the 12 accomplished ejaculation with a second male teaser. Total spermatozoa/ejaculate and daily sperm production were unaffected. However, treatment caused (P < 0.03) acrosomal dysgenesis and nuclear malformations. Baseline serum concentrations of LH were lower, but with borderline significance (P = 0.05). Testosterone secretion after exogenous human chorionic gonadotrophin (P < 0.04) was low. Thus, even at 45 weeks after last exposure to drinking water pollutants, mating desire/ability, sperm quality, and Leydig cell function were subnormal.

Dizygotic twinning is not linked to variation at the alpha-inhibin locus on human chromosome 2.

Natural multiple pregnancy in women leading to dizygotic (DZ) twins is familial and varies across racial groups, suggesting a genetic predisposition. Mothers of DZ twins have a higher incidence of spontaneous multiple ovulation and elevated FSH concentrations. FSH release is controlled by feedback of inhibin peptides from the ovary, and immunization against inhibin alpha-subunit results in an increased ovulation rate in animals. The inhibin alpha-subunit is therefore a candidate gene for mutations that may increase the frequency of DZ twinning. Restriction digests of a PCR product from exon 1 with the enzyme SpeI detects a C/T polymorphism at bp 128 with two alleles of 447 and 323/124 bp. The polymorphism was typed in 1,125 individuals from 326 pedigrees with 717 mothers of spontaneous DZ twins. The alpha-inhibin locus mapped within 3 centimorgans of D2S164, and linkage with DZ twinning was excluded [decimal log odds ratio (LOD) score, -2.81 at theta = 0]. There was complete exclusion of linkage (LOD, less than -2) of a gene conferring relative risk 1.8 (lambdas, >1.8) across the chromosome, except at the p-terminus region and a small peak (maximum LOD score, 0.6) in the region of D2S151-D2S326. Analysis using either recessive or dominant models excluded linkage with DZ twinning in this population (LOD score, less than -2.5) across chromosome 2. We conclude that dizygotic twinning is not linked to variation in the alpha-inhibin locus. The results also suggest that mutations in other candidates on chromosome 2, including the receptor for FSH and the betaB-inhibin subunit (INHBB) cannot be major contributors to risk for DZ twinning.

Erectile dysfunction in patients with spina bifida is a treatable condition.

PURPOSE: Now that individuals with spina bifida live well into adulthood erectile dysfunction has become a recognized associated medical disorder. To our knowledge no study has dealt specifically with treatment of erectile dysfunction in men with spina bifida. Therefore, we conducted a prospective, blinded, randomized, placebo controlled, dose escalation, crossover study to determine the ability to treat erectile dysfunction in men with spina bifida with sildenafil citrate. MATERIALS AND METHODS: Erectile dysfunction was diagnosed in 15 men 19 to 35 years old with spina bifida who were assigned to take 4 sets of tablets, 5 tablets per set, in a random order. All patients took 25 and 50 mg. sildenafil and 2 identical looking sets of corresponding placebos 1 hour before planned sexual activity. Efficacy was assessed by the effect of treatment compared to baseline, that is before treatment, on rating of erections (scored from 0 to 10), duration of erections, frequency of erections based on response to question 1 (scored from 0 to 5) of the International Index of Erectile Function and confidence to obtain an erection based on response to question 15 (scored from 1 to 5) of the International Index of Erectile Function. RESULTS: Improved erectile function was reported while on sildenafil by 12 (80%) men compared to baseline and placebos. There was a significant dose dependent improvement of erectile function with both 25 and 50 mg. sildenafil compared to baseline (p <0.05), as mean erectile score increased by 50% and 88%, mean duration of erections increased by 192% and 266%, mean frequency of erections increased by 61% and 96%, and mean level of confidence increased by 33% and 63%, respectively. Furthermore, 50 mg. sildenafil provided greater improvement in all 4 parameters compared to 25 mg. The placebo results were not significantly different compared to baseline for any of the parameters. CONCLUSIONS: Erectile dysfunction in patients with spina bifida is a medically treatable condition. Sildenafil is effective in this patient population and improves level of sexual confidence.