Genetic abnormalities leading to qualitative defects of sperm morphology or function.

Infertility, defined by the inability of conceiving a child after 1 year is estimated to concern approximately 50 million couples worldwide. As the male gamete is readily accessible and can be studied by a simple spermogram it is easier to subcategorize male than female infertility. Subjects with a specific sperm phenotype are more likely to have a common origin thus facilitating the search for causal factors. Male infertility is believed to be often multifactorial and caused by both genetic and extrinsic factors, but severe cases of male infertility are likely to have a predominant genetic etiology. Patients presenting with a monomorphic teratozoospermia such as globozoospermia or macrospermia with more than 85% of the spermatozoa presenting this specific abnormality have been analyzed permitting to identify several key genes for spermatogenesis such as AURKC and DPY19L2. The study of patients with other specific sperm anomalies such as severe alteration of sperm motility, in particular multiple morphological anomalies of the sperm flagella (MMAF) or sperm unability to fertilize the oocyte (oocyte activation failure syndrome) has also enable the identification of new infertility genes. Here we review the recent works describing the identification and characterization of gene defects having a direct qualitative effect on sperm morphology or function.

Single gene defects leading to sperm quantitative anomalies.

Azoospermia, defined by the absence of sperm in the ejaculate, is estimated to affect up to 1% of men in the general population. Assisted reproductive technologies have revolutionized the treatment of infertility, and some azoospermic men, those with a post-meiotic defect, can conceive following the use of viable spermatoza recovered from testicular or epididymal biopsies. Although male infertility is a multifactorial disease, it is believed that genetic factors are predominant in the etiology of azoospermia and severe oligozoospermia. Despite that assumption, substantiated by the high number of infertile knockout (KO) mice and the even higher number of genes expressed essentially in the testis, little is known about the pathophysiology of reduced sperm production, its primary causes or the genetic and epigenetic consequences for the gamete and the future conceptus. The identification of genetic abnormalities is therefore paramount to understand spermatogenesis, to adopt the best course of action for the patient and to provide adequate genetic counseling. We provide here a review of the recent literature on the genetics of azoospermia and oligozoospermia, focusing on defects directly altering sperm production. New sequencing technologies are contributing to the rapid evolution of the recent field of infertility genetics.

Incidence and risk factors for post-operative complications after scoliosis surgery in patients with Duchenne muscular dystrophy : a comparison with other neuromuscular conditions.

We report the incidence of and risk factors for complications after scoliosis surgery in patients with Duchenne muscular dystrophy (DMD) and compare them with those of other neuromuscular conditions. We identified 110 (64 males, 46 females) consecutive patients with a neuromuscular disorder who underwent correction of the scoliosis at a mean age of 14 years (7 to 19) and had a minimum two-year follow-up. We recorded demographic and peri-operative data, including complications and re-operations. There were 60 patients with cerebral palsy (54.5%) and 26 with DMD (23.6%). The overall complication rate was 22% (24 patients), the most common of which were deep wound infection (9, 8.1%), gastrointestinal complications (5, 4.5%) and hepatotoxicity (4, 3.6%). The complication rate was higher in patients with DMD (10/26, 38.5%) than in those with other neuromuscular conditions (14/84, 16.7% (p = 0.019). All hepatotoxicity occurred in patients with DMD (p = 0.003), who also had an increased rate of deep wound infection (19% vs 5%) (p = 0.033). In the DMD group, no peri-operative factors were significantly associated with the rate of overall complications or deep wound infection. Increased intra-operative blood loss was associated with hepatotoxicity (p = 0.036). In our series, correction of a neuromuscular scoliosis had an acceptable rate of complications: patients with DMD had an increased overall rate compared with those with other neuromuscular conditions. These included deep wound infection and hepatotoxicity. Hepatotoxicity was unique to DMD patients, and we recommend peri-operative vigilance after correction of a scoliosis in this group.

Mercury proxies and mercury dynamics in a forested watershed of the US Northeast.

Although many studies focus on mercury (Hg) and methylmercury (MeHg) dynamics in streams, challenges remain in identifying the relative importance of land cover and seasonality at regulating Hg and MeHg dynamics at the watershed scale. Developing robust proxies for Hg and/or MeHg determination also remains a challenge. Our study used Hg, MeHg, and dissolved organic carbon (DOC) concentration measurements and various DOC fluorescence indices to characterize Hg and DOC dynamics in a forested watershed of the US Northeast. Principal component analysis indicated that land cover/landscape position (i.e., headwater vs. wetland-influenced area vs. lake-influenced area) explained 44 % of the variance in Hg, MeHg, DOC concentrations, and DOC quality during the snow-free season, while seasonality (i.e., air temperature and discharge) explained only 21 % of the variance in the results. Furthermore, finding a good proxy for Hg that is valid across a range of landscape positions remains a challenge; however, regression analysis indicated that the fluorescence peak Humic C (excitation = 350 nm; emission = max (420-480)), which corresponds to the presence of melanoidins in water, explained 21 % of the variability in MeHg concentrations across both space and time (p = 0.001), and thus appears to be a possible proxy for MeHg determination in our study watershed. From a management perspective, land cover modifications (lake, reservoir, and wetland) are likely to play more important roles at regulating Hg, MeHg, and DOC exports at the watershed scale than long-term changes in the climate of this region.

Radiotherapy or tamoxifen after conserving surgery for breast cancers of excellent prognosis: British Association of Surgical Oncology (BASO) II trial.

BACKGROUND: The incidence of local recurrence (LR) after conservative surgery for early breast cancer without adjuvant therapy is unacceptably high even with favourable tumours. The aim of this study was to examine the effect of adjuvant therapies in tumours with excellent prognostic features. METHODS: Patients with primary invasive breast cancer <2 cm diameter, grade 1 or good prognosis special type, and node negative, treated by wide local excision (WLE) with clear margins were randomised into a 2 × 2 clinical trial of factorial design with or without radiotherapy and with or without tamoxifen. Trial entry was allowed to either comparison or both. FINDINGS: The actuarial breast cancer specific survival in 1135 randomised patients at 10 years was 96%. Analysis by intention to treat showed that LR after WLE was reduced in patients randomised to radiotherapy (RT) (HR 0.37, CI 0.22-0.61 p<0.001) and to tamoxifen (HR 0.33, CI 0.15 - 0.70 p<0.004). Actuarial analysis of patients entered into the four-way randomisation showed that LR after WLE alone was 1.9% per annum (PA) versus 0.7% with RT alone and 0.8% with tamoxifen alone. No patient randomised to both adjuvant treatments developed LR. Analysis by treatment received showed LR at 2.2%PA for surgery alone versus 0.8% for either adjuvant radiotherapy or tamoxifen and 0.2% for both treatments. CONCLUSIONS: Even in these patients with tumours of excellent prognosis, LR after conservative surgery without adjuvant therapy was still very high. This was reduced to a similar extent by either radiotherapy or tamoxifen but to a greater extent by the receipt of both treatments.

Factors contributing to variability of quantitative viral PCR results in proficiency testing samples: a multivariate analysis.

While viral load testing has gained widespread acceptance, a primary limitation remains the variability of results, particularly between different laboratories. While some work has demonstrated the importance of standardized quantitative control material in reducing this variability, little has been done to explore other important factors in the molecular amplification process. Results of 185 laboratories enrolled in the College of American Pathologists (CAP) 2009 viral load proficiency testing (PT) survey (VLS) were examined. This included 165 labs (89.2%) testing for cytomegalovirus (CMV), 99 (53.5%) for Epstein-Barr virus (EBV), and 64 (34.6%) for BK virus (BKV). At the time of PT, laboratories were asked a series of questions to characterize their testing methods. The responses to these questions were correlated to mean viral load (MVL) and result variability (RV). Contribution of individual factors to RV was estimated through analysis of variance (ANOVA) modeling and the use of backward selection of factors to fit those models. Selection of the quantitative calibrator, commercially prepared primers and probes, and amplification target gene were found most prominently associated with changes in MVL or RV for one or more of the viruses studied. Commercially prepared primers and probes and amplification target gene made the largest contribution to overall variability. Factors contributing to MVL and RV differed among viruses, as did relative contribution of each factor to overall variability. The marked variability seen in clinical quantitative viral load results is associated with multiple aspects of molecular testing design and performance. The reduction of such variability will require a multifaceted approach to improve the accuracy, reliability, and clinical utility of these important tests.

Molecular characterization of 11 novel mutations in patients with heterozygous and homozygous FV deficiency.

Coagulation factor V (FV) has an important role in the blood coagulation cascade, in both the pro- and anticoagulant pathways. FV deficiency is a rare bleeding disorder with variable phenotypic expression. We report a cohort of 10 patients with mild-severe FV deficiency in whom a total of 11 novel mutations were identified. Three patients were compound heterozygous for two mutations, whereas each of the remaining patients had a single heterozygous variant. FV levels did not correlate with either the type of mutation identified or the bleeding diathesis exhibited by the patients. Although considered to have an autosomal recessive mode of inheritance, patients with a single missense mutation may present with a significant bleeding history. The addition of a significant number of previously unidentified mutations to the public domain will contribute to the knowledge and understanding of the molecular pathology of this rare disorder.

The epidemiology of calcaneal fractures.

BACKGROUND: Calcaneal fractures are rare, but debilitating injuries, which occur frequently in younger individuals. The economic impact of the residual long-term disability that may occur after these injuries is therefore disproportionate to their incidence. The aim of this study was to review the epidemiology and injury patterns of this injury. METHODS: Data was extracted from a computer database, which prospectively coded all orthopaedic trauma events in a single unit between January 1995 and June 2005. Over this period 697 patients sustaining 752 fractures (55 bilateral) were treated in our unit. The patient's demographic details were prospectively recorded, together with details of their injury and primary treatment. The radiographs of a subgroup of patients were retrospectively examined in detail. RESULTS: The annual incidence of fracture was 11.5 per 100,000, and occurred 2.4 times more frequently in males than females. In males, the incidence was 16.5/100,000/year, with a peak incidence in the age range 20-29 (21.6/100,000/year). In females, the overall incidence was 6.26/100,000/year, with a more even spread throughout the age cohorts and showing a gradual increase in incidence towards the post-menopausal years. The majority of fractures were sustained in falls from a height (71.5%), and 64.3% of these were from 6 feet and above. Only 18.8% of fractures occurred in the workplace, and although manual workers made up the largest occupational group, significant numbers occurred in both unemployed and the retired. Most injuries occurred in isolation but the most commonly seen concomitant injuries were lower limb (13.2%) or spinal injuries (6.3%). Conventional radiography in a subgroup of the patients showed an average Böhler's angle of 16.5 degrees with no difference between the males and females. There was a strong association between the severity of the fracture, as assessed using the Sanders classification on computerised tomography, and the degree of depression of the Böhler's angle (p=0.002).

Analysis of sex chromosome abnormalities using X and Y chromosome DNA tiling path arrays.

BACKGROUND: Array comparative genomic hybridisation is a powerful tool for the detection of copy number changes in the genome. METHODS: A human X and Y chromosome tiling path array was developed for the analysis of sex chromosome aberrations. RESULTS: Normal X and Y chromosome profiles were established by analysis with DNA from normal fertile males and females. Detection of infertile males with known Y deletions confirmed the competence of the array to detect AZFa, AZFb and AZFc deletions and to distinguish between different AZFc lesions. Examples of terminal and interstitial deletions of Xp (previously characterised through cytogenetic and microsatellite analysis) have been assessed using the arrays, thus both confirming and refining the established deletion breakpoints. Breakpoints in iso-Yq, iso-Yp and X-Y translocation chromosomes and X-Y interchanges in XX males are also amenable to analysis. DISCUSSION: The resolution of the tiling path clone set used allows breakpoints to be placed within 100-200 kb, permitting more precise genotype/phenotype correlations. These data indicate that the combined X and Y tiling path arrays provide an effective tool for the investigation and diagnosis of sex chromosome copy number aberrations and rearrangements.

Survival of invasive breast cancer according to the Nottingham Prognostic Index in cases diagnosed in 1990-1999.

UNLABELLED: The Nottingham Prognostic Index (NPI) is a well established and widely used method of predicting survival of operable primary breast cancer. AIMS: Primary: To present the updated survival figures for each NPI Group. Secondary: From the observations to suggest reasons for the reported fall in mortality from breast cancer. METHODS: The NPI is compiled from grade, size and lymph node status of the primary tumour. Consecutive cases diagnosed and treated at Nottingham City Hospital in 1980-1986 (n=892) and 1990-1999 (n=2,238) are compared. Changes in protocols towards earlier diagnosis and better case management were made in the late 1980s between the two data sets. RESULTS: Case survival (Breast Cancer Specific) at 10 years has improved overall from 55% to 77%. Within all Prognostic groups there are high relative and absolute risk reductions. The distribution of cases to Prognostic groups shows only a small increase in the numbers in better groups. CONCLUSION: The updated survival figures overall and for each Prognostic group for the NPI are presented.

Reading the prognosis of the individual with breast cancer.

AIM: To obtain better survival estimates for the individual than is provided by placement in an NPI group. METHOD: Consecutive primary operable breast cancers treated at Nottingham City Hospital 1990-1999. Ten year % actuarial survivals plotted for 10 ranges of NPI from 2.0 to 6.9. There is an excellent inverse correlation between median NPI value for each range and survival at 10 years. To enable estimation of survival for all individual values of NPI, a curve fitting technique applied to these results (by G.B.) gave the formula to estimate survival from the individual's NPI score: 10 year % survival for the individual=-3.0079 x NPI(2)+12.30 x NPI+83.84. This gave an r(2) of 0.98. RESULTS AND CONCLUSION: Greater accuracy in individual survival prediction is obtained by dividing women into 10 groups by NPI scores than in the originally described six groups; rank order of survival in relation to NPI score is preserved. A curve fitting technique has been applied to these data to give a formula for the prediction of 10 year survival for every 0.1 value of NPI.

Influence of ageing of residues on the availability of herbicides for leaching.

Losses by leaching of chlorotoluron, isoproturon and triasulfuron from small intact columns of a structured clay loam and an unstructured sandy loam soil were measured in five separate field experiments. In general, losses of all three herbicides were greater from the clay loam than from the sandy loam soil and the order between herbicides was always triasulfuron >> isoproturon > chlorotoluron. Differences between experiments were also consistent for every soil/herbicide combination. There was no relationship between total loss and either total rainfall or cumulative leachate volume. When weighting factors were applied to the rainfall data to make early rainfall more important than later rainfall, there were significant positive relationships between cumulative weighted rainfall and total losses. Also, there were significant negative correlations between total losses and the delay to accumulation of 25 mm rainfall (equivalent to one pore volume of available water) in the different experiments. In laboratory incubations, there was a more rapid decline in aqueous (0.01 M calcium chloride) extractable residues than in total solvent extractable residues indicating increasing sorption with residence time. However, the rate of change in water extractable residues could not completely explain the decrease in leachability with ageing of residues in the field. Short-term sorption studies with aggregates of the two soils indicated slower sorption by those of the clay loam than by those of the sandy loam suggesting that diffusion into and out of aggregates may affect availability for leaching in the more structured soil. Small scale leaching studies with aggregates of the soils also demonstrated reductions in availability for leaching as residence time in soil was increased, which could not be explained by degradation. These results therefore indicate that time-dependent sorption processes are important in controlling pesticide movement in soils, although the data do not give a mechanistic explanation of the changes in leaching with ageing of residues.

Sequence family variant loss from the AZFc interval of the human Y chromosome, but not gene copy loss, is strongly associated with male infertility.

BACKGROUND: Complete deletion of the complete AZFc interval of the Y chromosome is the most common known genetic cause of human male infertility. Two partial AZFc deletions (gr/gr and b1/b3) that remove some copies of all AZFc genes have recently been identified in infertile and fertile populations, and an association study indicates that the resulting gene dose reduction represents a risk factor for spermatogenic failure. METHODS: To determine the incidence of various partial AZFc deletions and their effect on fertility, we combined quantitative and qualitative analyses of the AZFc interval at the DAZ and CDY1 loci in 300 infertile men and 399 control men. RESULTS: We detected 34 partial AZFc deletions (32 gr/gr deletions), arising from at least 19 independent deletion events, and found gr/gr deletion in 6% of infertile and 3.5% of control men (p>0.05). Our data provide evidence for two large AZFc inversion polymorphisms, and for relative hot and cold spots of unequal crossing over within the blocks of homology that mediate gr/gr deletion. Using SFVs (sequence family variants), we discriminate DAZ1/2, DAZ3/4, CDY1a (proximal), and CDY1b (distal) and define four types of DAZ-CDY1 gr/gr deletion. CONCLUSIONS: The only deletion type to show an association with infertility was DAZ3/4-CDY1a (p = 0.042), suggesting that most gr/gr deletions are neutral variants. We see a stronger association, however, between loss of the CDY1a SFV and infertility (p = 0.002). Thus, loss of this SFV through deletion or gene conversion could be a major risk factor for male infertility.