Genetics of mitochondrial dysfunction and infertility.

Increasingly, mitochondria are being recognized as having an important role in fertility. Indeed in assisted reproductive technologies mitochondrial function is a key indicator of sperm and oocyte quality. Here, we review the literature regarding mitochondrial genetics and infertility. In many multisystem disorders caused by mitochondrial dysfunction death occurs prior to sexual maturity, or the clinical features are so severe that infertility may be underreported. Interestingly, many of the genes linked to mitochondrial dysfunction and infertility have roles in the maintenance of mitochondrial DNA or in mitochondrial translation. Studies on populations with genetically uncharacterized infertility have highlighted an association with mitochondrial DNA deletions, whether this is causative or indicative of poor functioning mitochondria requires further examination. Studies on the impact of mitochondrial DNA variants present conflicting data but highlight POLG as a particularly interesting candidate gene for both male and female infertility.

Glucocorticoid treatment regimen and health outcomes in adults with congenital adrenal hyperplasia.

BACKGROUND: Adults with congenital adrenal hyperplasia (CAH) are treated with a wide variety of glucocorticoid treatment regimens. OBJECTIVE, DESIGN AND METHODS: To test whether drug dose and timing of glucocorticoid treatment regimen impacts on health outcomes. This was a cross-sectional study of 196 adult CAH patients in whom treatment and health outcomes were measured. Glucocorticoid dose was converted to prednisolone dose equivalent (PreDEq) using three published formulae. Associations between the type of glucocorticoid regimen and PreDEq with specific health outcome variables were tested using partial correlation and principal components analysis (PCA). RESULTS: Patients on dexamethasone had lower androgens and ACTH but greater insulin resistance compared with those receiving hydrocortisone or prednisolone. Dexamethasone dose and once daily administration were associated with insulin resistance. Partial correlation analysis adjusted for age and sex showed PreDEq weakly correlated (r < 0·2) with blood pressure and androstenedione. Mutation severity was associated with increased PreDEq (F(3,141)  = 4·4, P < 0·01). In PCA, 3 PCs were identified that explained 62% of the total variance (r(2) ) in observed variables. Regression analysis (age and sex adjusted) confirmed that PC2, reflecting disease control (androstenedione, 17-hydroxypregesterone and testosterone), and PC3, reflecting blood pressure and mutations (systolic and diastolic blood pressure and mutation severity), related directly to PreDEq (r(2)  = 23%, P < 0·001). CONCLUSIONS: In adults with congenital adrenal hyperplasia, dexamethasone use was associated with lower androgens but greater insulin resistance, and increasing glucocorticoid dose associated with increased blood pressure, poor disease control and mutation severity.

Growth hormone effects on cortical bone dimensions in young adults with childhood-onset growth hormone deficiency.

UNLABELLED: Growth hormone (GH) treatment in young adults with childhood-onset GH deficiency has beneficial effects on bone mass. The present study shows that cortical bone dimensions also benefit from GH treatment, with endosteal expansion and increased cortical thickness leading to improved bone strength. INTRODUCTION: In young adults with childhood-onset growth hormone deficiency (CO GHD), GH treatment after final height is reached has been shown to have beneficial effects on spine and hip bone mineral density. The objective of the study was to evaluate the influence of GH on cortical bone dimensions. METHODS: Patients (n = 160; mean age, 21.2 years; 63% males) with CO GHD were randomised 2:1 to GH or no treatment for 24 months. Cortical bone dimensions were evaluated by digital x-ray radiogrammetry of the metacarpal bones every 6 months. RESULTS: After 24 months, cortical thickness was increased compared with the controls (6.43%, CI 3.34 to 9.61%; p = 0.0001) and metacarpal index (MCI) (6.14%, CI 3.95 to 8.38%; p < 0.0001), while the endosteal diameter decreased (-4.64%, CI -7.15 to -2.05; p < 0.001). Total bone width did not change significantly (0.68%, CI -1.17 to 2.57%; not significant (NS)). A gender effect was seen on bone width (p < 0.0001), endosteal diameter (p < 0.01) and cortical thickness (p < 0.01), but not with MCI (NS). CONCLUSIONS: Cortical bone reacts promptly to reinstitution of GH beyond the attainment of final height by increasing the cortical thickness through endosteal bone growth. This leads to a higher peak bone mass and may reduce the risk of cortical bone fragility later in life.

High-heat flux ball-pen probe head in ASDEX-Upgrade.

A new high heat flux ball-pen probe head installed on the midplane manipulator is currently being used in ASDEX-Upgrade (AUG). The probe was designed to withstand high heat fluxes making possible the investigation of the plasma edge under harsh conditions, such as low power H-mode. Composed of seven pins (four Langmuir probes, mounted in two Mach probe pairs, and three ball-pen probes), the new probe head allows us to measure several plasma parameters simultaneously and with high temporal resolution. A novel method to correct the sheath potential dynamically accounting for the total secondary electron emission is introduced together with applications to obtain the electron temperature and plasma potential profiles. The total secondary electron emission yield is obtained from particle in cell simulations in AUG condition and probe realistic impact angle with respect to the magnetic field. Finally, the probe capability to investigate turbulence around the separatrix of AUG is discussed.

Mean and oscillating plasma flows and turbulence interactions across the L-H confinement transition.

A complex interaction between turbulence driven E × B zonal flow oscillations, i.e., geodesic acoustic modes (GAMs), the turbulence, and mean equilibrium flows is observed during the low to high (L-H) plasma confinement mode transition in the ASDEX Upgrade tokamak. Below the L-H threshold at low densities a limit-cycle oscillation forms with competition between the turbulence level and the GAM flow shearing. At higher densities the cycle is diminished, while in the H mode the cycle duration becomes too short to sustain the GAM, which is replaced by large amplitude broadband flow perturbations. Initially GAM amplitude increases as the H-mode transition is approached, but is then suppressed in the H mode by enhanced mean flow shear.

Androgen-dependent measurements of female genitalia in women with complete androgen insensitivity syndrome.

Measurements of clitoral length and clitoral to urethral distance were made and analysed for a relationship in a group of 19 women with complete androgen insensitivity syndrome (CAIS)attending a specialist clinic for adult women with disorders of sexual development. These were compared with a control group of 50 women attending hospital for a gynaecological procedure.There was a positive correlation between clitoral length and clitoral to urethral distance for women with CAIS. In contrast, a negative correlation was seen between clitoral length and clitoral to urethral distance for women in the control group. Women with CAIS had a reduced mean clitoral length compared with controls(P = 0.001), but no difference was observed for the clitoral to urethral distance between the two groups (P = 0.116).

Analysis of X chromosome genomic DNA sequence copy number variation associated with premature ovarian failure (POF).

BACKGROUND: Premature ovarian failure (POF) is a heterogeneous disease defined as amenorrhoea for >6 months before age 40, with an FSH serum level >40 mIU/ml (menopausal levels). While there is a strong genetic association with POF, familial studies have also indicated that idiopathic POF may also be genetically linked. Conventional cytogenetic analyses have identified regions of the X chromosome that are strongly associated with ovarian function, as well as several POF candidate genes. Cryptic chromosome abnormalities that have been missed might be detected by array comparative genomic hybridization. METHODS: In this study, samples from 42 idiopathic POF patients were subjected to a complete end-to-end X/Y chromosome tiling path array to achieve a detailed copy number variation (CNV) analysis of X chromosome involvement in POF. The arrays also contained a 1 Mb autosomal tiling path as a reference control. Quantitative PCR for selected genes contained within the CNVs was used to confirm the majority of the changes detected. The expression pattern of some of these genes in human tissue RNA was examined by reverse transcription (RT)-PCR. RESULTS: A number of CNVs were identified on both Xp and Xq, with several being shared among the POF cases. Some CNVs fall within known polymorphic CNV regions, and others span previously identified POF candidate regions and genes. CONCLUSIONS: The new data reported in this study reveal further discrete X chromosome intervals not previously associated with the disease and therefore implicate new clusters of candidate genes. Further studies will be required to elucidate their involvement in POF.

The clandestine uterus: or how the uterus escapes detection prior to puberty.

Uterine agenesis is one of the differential diagnoses in adolescent girls with delayed menstruation. It may also be suspected earlier in childhood during investigations for other genitourinary conditions. However, accurate confirmation that the uterus is absent can be extremely difficult before puberty because of its small size. We describe ten girls referred to a specialist centre with a presumed diagnosis of an absent uterus which was later found to be incorrect. We conclude that imaging should be undertaken by clinicians with experience in management of this age group and in some girls it may be necessary to delay final diagnosis until after puberty.

Service users' experiences of obtaining and giving information about disorders of sex development.

OBJECTIVE: To quantify participants' experiences of obtaining and giving information about disorders of sex development (DSD). DESIGN: Cross-sectional survey study that asked people about their current and past experiences relating to DSD disclosure. SETTING: A large tertiary referral centre for DSD management in the UK. POPULATION: One hundred of 126 people with a confirmed diagnosis of DSD who were invited to participate in the study formed the usable sample. METHODS: All people who attended clinic for follow-up during the study period and members of a patient support group whose annual meeting fell within the study period were asked to complete the Middlesex Communication Survey. MAIN OUTCOME MEASURES: The Middlesex Communication Survey. RESULTS: Younger participants were more likely to report having been appropriately informed about their diagnosis than older people. Nearly half of the former had been fully informed about their diagnosis by age 15 years, compared with 0% of the older age group. In terms of information sharing, mothers were most likely to be the person with whom the participant had shared (almost/all) DSD information (74%), followed by current partners (71%). Information relating to genital surgery, presence of testes and clitoral anomalies were the least likely aspects to have been unambiguously shared with even the most informed person. CONCLUSIONS: Our results suggest that difficulties in obtaining DSD information from care providers were common, and that communication has improved for younger participants. The study also confirmed that many people with DSD continue to struggle with confiding, even in those closest to them, about aspects of their diagnosis. Care protocol needs to centralise psychological adaptation, which should also be a primary focus for future research.

Turner's syndrome in adulthood.

Turner's syndrome is the most common chromosomal abnormality in females, affecting 1:2,500 live female births. It is a result of absence of an X chromosome or the presence of a structurally abnormal X chromosome. Its most consistent clinical features are short stature and ovarian failure. However, it is becoming increasingly evident that adults with Turner's syndrome are also susceptible to a range of disorders, including osteoporosis, hypothyroidism, and renal and gastrointestinal disease. Women with Turner's syndrome have a reduced life expectancy, and recent evidence suggests that this is due to an increased risk of aortic dissection and ischemic heart disease. Up until recently, women with Turner's syndrome did not have access to focused health care, and thus quality of life was reduced in a significant number of women. All adults with Turner's syndrome should therefore be followed up by a multidisciplinary team to improve life expectancy and reduce morbidity.

Swyer syndrome: presentation and outcomes.

OBJECTIVE: To establish the spectrum of presentation, natural history and gynaecological outcomes in women with Swyer syndrome. DESIGN: Retrospective notes review. SETTING: Tertiary referral centre for disorders of sex development. POPULATION: A total of 29 adult women with Swyer syndrome. METHODS: Information was collected on age at diagnosis, biometric characteristics, timing of gonadectomy, histology of gonad, bone mineral density, uterine size and fertility. MAIN OUTCOME MEASURES: Age at diagnosis, risk of gonadal malignancy, bone mineral density, uterine size. RESULTS: With regard to presentation, 26/29 (90%) women in this series presented with delayed puberty, and the median age at diagnosis was 17.2 years (range 0-55 years). The median age at gonadectomy was 18 years (range 9-33 years). Histology of the gonad was available in 22 women and demonstrated streak gonads with no evidence of malignancy in 12, dysgerminoma in 7 and gonadoblastoma in 3. The youngest patient diagnosed with dysgerminoma was 10 years old. The median height of the women was 1.73 m (range 1.54-1.95 m). Twelve out of the 20 (60%) women had evidence of osteopenia on dual energy X-ray absorptiometry scan. The uterine size and shape was assessed in eight women after completion of induction of puberty, and the uterine cross-section was found to be significantly lower than that in normal controls. Fertility was achieved with ovum donation in three women, all of whom had live births and one subsequently had a second successful pregnancy. CONCLUSION: Early diagnosis of Swyer syndrome is necessary in view of the risk of dysgerminoma that can develop at an early age. Adequate hormone replacement is required to maintain bone mineral density and may improve the uterine size and shape.

Turbulence level effects on conventional reflectometry using 2D full-wave simulations.

Numerical simulations are critical in improving the capabilities of microwave diagnostics. In this work, the 2D finite-difference time-domain full-wave code REFMUL was applied to broadband turbulent plasmas using the conventional reflectometry setup. Simulations were performed with O-mode waves, fixed frequency probing, and I/Q detection. The plasma density, determining O-mode propagation, was modeled as the sum of a slab background plasma with a fluctuating component following a Kolmogorov-like amplitude k-spectrum. The density turbulence level δn e/n e was scanned over several orders of magnitude for simulated plasma flows of constant plasma velocity in either the radial or the poloidal direction. Simulations show trends, such as spectral broadening of the complex A(t)eiφ(t) signals and increasing fluctuations in A(t) and φ(t) with increasing δn e/n e, that are similar for both plasma flow directions. These together with possibilities to reconstruct a poloidal wavenumber spectrum are discussed in view of extending the measuring capabilities. The onset of non-linear effects associated with phase runaway, as previously observed with other 1D and 2D codes, as well as radial Doppler effects is also observed and discussed.

Correlation electron cyclotron emission diagnostic and improved calculation of turbulent temperature fluctuation levels on ASDEX Upgrade.

A newly upgraded correlation electron cyclotron emission (CECE) diagnostic has been installed on the ASDEX Upgrade tokamak and has begun to perform experimental measurements of electron temperature fluctuations. CECE diagnostics measure small amplitude electron temperature fluctuations by correlating closely spaced heterodyne radiometer channels. This upgrade expanded the system from six channels to thirty, allowing simultaneous measurement of fluctuation level radial profiles without repeat discharges, as well as opening up the possibility of measuring radial turbulent correlation lengths. Newly refined statistical techniques have been developed in order to accurately analyze the fluctuation data collected from the CECE system. This paper presents the hardware upgrades for this system and the analysis techniques used to interpret the raw data, as well as measurements of fluctuation spectra and fluctuation level radial profiles.

Ribonucleoproteins package 700 nucleotides of pre-mRNA into a repeating array of regular particles.

An assay for the in vitro assembly of HeLa cell 40S nuclear ribonucleoprotein particles (hnRNP particles) has been developed. The substrates were single-stranded nucleic acid polymers of defined length and sequence prepared in vitro and the six major core particle proteins from isolated 40S hnRNP. The fidelity of in vitro assembly was evaluated on various physical parameters, including sedimentation, salt dissociation, polypeptide stoichiometry, UV-activated protein-RNA cross-linking, and overall morphology. Correct particle assembly depended on RNA length and on the input protein/RNA ratio but not on the concentration of the reactant mixture nor on the presence or absence of internal RNA processing signals, a 5'-cap structure, a 3'-poly(A) moiety, or ATP as energy source. RNA lengths between 685 and 726 nucleotides supported correct particle assembly. Dimers and oligomeric complexes that possessed the same polypeptide stoichiometry as native hnRNP assembled on RNA chains that were integral multiples of 700 nucleotides. Intermediate-length RNA supported the assembly of nonstoichiometric complexes lacking structural homogeneity. An analysis of these complexes indicates that proteins A1 and A2 may be the first proteins to bind RNA during particle assembly. We conclude that the major proteins of 40S hnRNP particles contain the necessary information for packaging nascent transcripts into a repeating "ribonucleosomal" structure possessing a defined RNA length and protein composition but do not themselves contain the information for modulating packaging that may be required for RNA splicing.

Multiple splicing factors are released from endogenous complexes during in vitro pre-mRNA splicing.

Pre-mRNA splicing occurs in a macromolecular complex called the spliceosome. Efforts to isolate spliceosomes from in vitro splicing reactions have been hampered by the presence of endogenous complexes that copurify with de novo spliceosomes formed on added pre-mRNA. We have found that removal of these large complexes from nuclear extracts prevents the splicing of exogenously added pre-mRNA. We therefore examined these complexes for the presence of splicing factors and proteins known or thought to be involved in RNA splicing. These fast-sedimenting structures were found to contain multiple small nuclear ribonucleoproteins (snRNPs) and a fragmented heterogeneous nuclear ribonucleoprotein complex. At least two splicing factors other than the snRNPs were also associated with these large structures. Upon incubation with ATP, these splicing factors as well as U1 and U2 snRNPs were released from these complexes. The presence of multiple splicing factors suggests that these complexes may be endogenous spliceosomes released from nuclei during preparation of splicing extracts. The removal of these structures from extracts that had been preincubated with ATP yielded a splicing extract devoid of large structures. This extract should prove useful in the fractionation of splicing factors and the isolation of native spliceosomes formed on exogenously added pre-mRNA.

The impact of co-existing immune-mediated diseases on phenotype and outcomes in inflammatory bowel diseases.

BACKGROUND: Inflammatory bowel diseases lead to progressive bowel damage and need for surgery. While the increase in prevalence of other immune-mediated diseases in IBD is well recognised, the impact of this on the natural history of IBD is unknown. AIM: To determine the impact of concomitant immune-mediated diseases on phenotypes and outcomes in IBD. METHODS: Patients with IBD enrolled in a prospective registry were queried about the presence of other immune-mediated diseases, defined as those where immune dysregulation plays a role in pathogenesis. Demographics and disease-related information were obtained. Subjects also completed measures of quality of life. Multivariable regression models compared disease phenotype and outcomes of IBD patients with and without other immune-mediated diseases. RESULTS: The cohort included 2145 IBD patients among whom 458 (21%) had another immune-mediated disease. There was no difference in CD phenotype between the two groups. UC patients were more likely to have pancolitis in the presence of another immune-mediated disease (62%) compared to those without (52%, P = 0.02). IBD patients with another immune-mediated disease had higher rates of needing anti-TNF biologics [Odds ratio (OR) 1.31, 95% CI 1.05-1.63] and surgery (OR 1.26, 95% CI 0.99-1.61). The presence of another immune-mediated disease was also associated with lower disease-specific and general physical quality of life. CONCLUSIONS: The presence of another immune-mediated disease in IBD patients was associated with higher likelihood of pancolonic involvement in UC, and a modest increase in need for IBD-related surgery and anti-TNF biological therapy. Such patients also experienced worse quality of life.

1 µs broadband frequency sweeping reflectometry for plasma density and fluctuation profile measurements.

Frequency swept reflectometry has reached the symbolic value of 1 µs sweeping time; this performance has been made possible, thanks to an improved control of the ramp voltage driving the frequency source. In parallel, the memory depth of the acquisition system has been upgraded and can provide up to 200 000 signals during a plasma discharge. Additional improvements regarding the trigger delay determination of the acquisition and the voltage ramp linearity required by this ultra-fast technique have been set. While this diagnostic is traditionally dedicated to the plasma electron density profile measurement, such a fast sweeping rate can provide the study of fast plasma events and turbulence with unprecedented time and radial resolution from the edge to the core. Experimental results obtained on ASDEX Upgrade plasmas are presented to demonstrate the performances of the diagnostic.

Measurement of turbulent electron temperature fluctuations on the ASDEX Upgrade tokamak using correlated electron cyclotron emission.

Turbulent temperature fluctuations are measured on the ASDEX Upgrade tokamak using pairs of closely spaced, narrow-band heterodyne radiometer channels and a standard correlation technique. The pre-detection spacing and bandwidth of the radiometer channel pairs is chosen such that they are physically separated less than a turbulent correlation length, but do not overlap. The radiometer has 4 fixed filter frequency channels and two tunable filter channels for added flexibility in the measurement position. Relative temperature fluctuation amplitudes are observed in a helium plasma to be δT/T = (0.76 ± 0.02)%, (0.67 ± 0.02)%, and (0.59 ± 0.03)% at normalised toroidal flux radius of ρtor = 0.82, 0.75, and 0.68, respectively.

Implementation of the new multichannel X-mode edge density profile reflectometer for the ICRF antenna on ASDEX Upgrade.

A new multichannel frequency modulated continuous-wave reflectometry diagnostic has been successfully installed and commissioned on ASDEX Upgrade to measure the plasma edge electron density profile evolution in front of the Ion Cyclotron Range of Frequencies (ICRF) antenna. The design of the new three-strap ICRF antenna integrates ten pairs (sending and receiving) of microwave reflectometry antennas. The multichannel reflectometer can use three of these to measure the edge electron density profiles up to 2 × 1019 m-3, at different poloidal locations, allowing the direct study of the local plasma layers in front of the ICRF antenna. ICRF power coupling, operational effects, and poloidal variations of the plasma density profile can be consistently studied for the first time. In this work the diagnostic hardware architecture is described and the obtained density profile measurements were used to track outer radial plasma position and plasma shape.