Study of High-Transverse-Momentum Higgs Boson Production in Association with a Vector Boson in the qqbb Final State with the ATLAS Detector

This Letter presents the first study of Higgs boson production in association with a vector boson (V=W or Z) in the fully hadronic qqbb final state using data recorded by the ATLAS detector at the LHC in proton-proton collisions at sqrt[s]=13  TeV and corresponding to an integrated luminosity of 137  fb^{-1}. The vector bosons and Higgs bosons are each reconstructed as large-radius jets and tagged using jet substructure techniques. Dedicated tagging algorithms exploiting b-tagging properties are used to identify jets consistent with Higgs bosons decaying into bb[over ¯]. Dominant backgrounds from multijet production are determined directly from the data, and a likelihood fit to the jet mass distribution of Higgs boson candidates is used to extract the number of signal events. The VH production cross section is measured inclusively and differentially in several ranges of Higgs boson transverse momentum: 250-450, 450-650, and greater than 650 GeV. The inclusive signal yield relative to the standard model expectation is observed to be μ=1.4_{-0.9}^{+1.0} and the corresponding cross section is 3.1±1.3(stat)_{-1.4}^{+1.8}(syst)  pb.

Measurement of the Centrality Dependence of the Dijet Yield in p+Pb Collisions at sqrt[s_{NN}]=8.16 TeV with the ATLAS Detector

ATLAS measured the centrality dependence of the dijet yield using 165  nb^{-1} of p+Pb data collected at sqrt[s_{NN}]=8.16  TeV in 2016. The event centrality, which reflects the p+Pb impact parameter, is characterized by the total transverse energy registered in the Pb-going side of the forward calorimeter. The central-to-peripheral ratio of the scaled dijet yields, R_{CP}, is evaluated, and the results are presented as a function of variables that reflect the kinematics of the initial hard parton scattering process. The R_{CP} shows a scaling with the Bjorken x of the parton originating from the proton, x_{p}, while no such trend is observed as a function of x_{Pb}. This analysis provides unique input to understanding the role of small proton spatial configurations in p+Pb collisions by covering parton momentum fractions from the valence region down to x_{p}∼10^{-3} and x_{Pb}∼4×10^{-4}.

Search for New Phenomena in Two-Body Invariant Mass Distributions Using Unsupervised Machine Learning for Anomaly Detection at sqrt[s]=13 TeV with the ATLAS Detector

Searches for new resonances are performed using an unsupervised anomaly-detection technique. Events with at least one electron or muon are selected from 140  fb^{-1} of pp collisions at sqrt[s]=13  TeV recorded by ATLAS at the Large Hadron Collider. The approach involves training an autoencoder on data, and subsequently defining anomalous regions based on the reconstruction loss of the decoder. Studies focus on nine invariant mass spectra that contain pairs of objects consisting of one light jet or b jet and either one lepton (e,μ), photon, or second light jet or b jet in the anomalous regions. No significant deviations from the background hypotheses are observed. Limits on contributions from generic Gaussian signals with various widths of the resonance mass are obtained for nine invariant masses in the anomalous regions.

Observation of WZγ Production in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

This Letter reports the observation of WZγ production and a measurement of its cross section using 140.1±1.2  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. The WZγ production cross section, with both the W and Z bosons decaying leptonically, pp→WZγ→ℓ^{'}^{±}νℓ^{+}ℓ^{-}γ (ℓ^{(^{'})}=e, μ), is measured in a fiducial phase-space region defined such that the leptons and the photon have high transverse momentum and the photon is isolated. The cross section is found to be 2.01±0.30(stat)±0.16(syst)  fb. The corresponding standard model predicted cross section calculated at next-to-leading order in perturbative quantum chromodynamics and at leading order in the electroweak coupling constant is 1.50±0.06  fb. The observed significance of the WZγ signal is 6.3σ, compared with an expected significance of 5.0σ.

Combined Measurement of the Higgs Boson Mass from the H→γγ and H→ZZ^{*}→4ℓ Decay Channels with the ATLAS Detector Using sqrt[s]=7, 8, and 13 TeV pp Collision Data

A measurement of the mass of the Higgs boson combining the H→ZZ^{*}→4ℓ and H→γγ decay channels is presented. The result is based on 140  fb^{-1} of proton-proton collision data collected by the ATLAS detector during LHC run 2 at a center-of-mass energy of 13 TeV combined with the run 1 ATLAS mass measurement, performed at center-of-mass energies of 7 and 8 TeV, yielding a Higgs boson mass of 125.11±0.09(stat)±0.06(syst)=125.11±0.11  GeV. This corresponds to a 0.09% precision achieved on this fundamental parameter of the Standard Model of particle physics.

Search for Dark Photons in Rare Z Boson Decays with the ATLAS Detector

A search for events with a dark photon produced in association with a dark Higgs boson via rare decays of the standard model Z boson is presented, using 139  fb^{-1} of sqrt[s]=13  TeV proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider. The dark boson decays into a pair of dark photons, and at least two of the three dark photons must each decay into a pair of electrons or muons, resulting in at least two same-flavor opposite-charge lepton pairs in the final state. The data are found to be consistent with the background prediction, and upper limits are set on the dark photon's coupling to the dark Higgs boson times the kinetic mixing between the standard model photon and the dark photon, α_{D}ϵ^{2}, in the dark photon mass range of [5, 40] GeV except for the ϒ mass window [8.8, 11.1] GeV. This search explores new parameter space not previously excluded by other experiments.

Measurement of the Sensitivity of Two-Particle Correlations in pp Collisions to the Presence of Hard Scatterings

A key open question in the study of multiparticle production in high-energy pp collisions is the relationship between the "ridge"-i.e., the observed azimuthal correlations between particles in the underlying event that extend over all rapidities-and hard or semihard scattering processes. In particular, it is not known whether jets or their soft fragments are correlated with particles in the underlying event. To address this question, two-particle correlations are measured in pp collisions at sqrt[s]=13  TeV using data collected by the ATLAS experiment at the LHC, with an integrated luminosity of 15.8  pb^{-1}, in two different configurations. In the first case, charged particles associated with jets are excluded from the correlation analysis, while in the second case, correlations are measured between particles within jets and charged particles from the underlying event. Second-order flow coefficients, v_{2}, are presented as a function of event multiplicity and transverse momentum. These measurements show that excluding particles associated with jets does not affect the measured correlations. Moreover, particles associated with jets do not exhibit any significant azimuthal correlations with the underlying event, ruling out hard processes contributing to the ridge.

Observation of an Excess of Dicharmonium Events in the Four-Muon Final State with the ATLAS Detector

A search is made for potential ccc[over ¯]c[over ¯] tetraquarks decaying into a pair of charmonium states in the four muon final state using proton-proton collision data at sqrt[s]=13  TeV, corresponding to an integrated luminosity of 140  fb^{-1} recorded by the ATLAS experiment at LHC. Two decay channels, J/ψ+J/ψ→4μ and J/ψ+ψ(2S)→4μ, are studied. Backgrounds are estimated based on a hybrid approach involving Monte Carlo simulations and data-driven methods. Statistically significant excesses with respect to backgrounds dominated by the single parton scattering are seen in the di-J/ψ channel consistent with a narrow resonance at 6.9 GeV and a broader structure at lower mass. A statistically significant excess is also seen in the J/ψ+ψ(2S) channel. The fitted masses and decay widths of the structures are reported.

Effect of exercise training on vascular function and endothelial repair in heart failure with preserved ejection fraction: results from the OptimEx trial

Background

Exercise training improves peak oxygen uptake (VO2) in heart failure with preserved ejection fraction (HFpEF), but the underlying mechanisms are unknown. In other cardiovascular diseases, exercise training improves vascular function and increases levels of circulating endothelium-repairing cells. We aimed to investigate the effects of moderate continuous training (MCT) and high intensity interval training (HIIT) on vascular function and cellular endothelial repair in HFpEF.

Methods

This was a prespecified subanalysis of the Optimizing Exercise Training in Prevention and Treatment of Diastolic Heart Failure randomized trial. HFpEF patients (n=180) were randomized to HIIT, MCT or attention control. At baseline and after 12 weeks, we measured peak VO2, fingertip arterial tonometry (n=109), brachial artery flow-mediated dilation (n=59), aortic pulse wave velocity (n=94), and flow cytometry (n=136) for endothelial progenitor cells (CD45dimCD34+VEGFR2+) and angiogenic T cells (CD3+CD31+CD184+). Changes in these parameters were compared between groups using linear mixed models. Parameters were correlated using Spearman's rho.

Results

At 3 months, we did not observe significant differences between HIIT, MCT and control group regarding changes in vascular function throughout the vascular tree (fingertip arterial tonometry, brachial artery flow-mediated dilation and central arterial stiffness, Table 1) or levels of circulating endothelium-repairing cells (endothelial progenitor cells and angiogenic T cells, Table 1). Results were similar at 12 months and when restricting analysis to patients with at least 70% adherence to training sessions. Patients with higher peak VO2 at baseline had lower numbers of circulating endothelial progenitor cells (rho=−0.22, p=0.011).

Conclusions

In patients with HFpEF, exercise training did not change vascular function or levels of endothelium-repairing cells. Thus, improved vascular function likely does not contribute to the change in peak VO2 after training. These findings are in contrast with the benefits of exercise on vascular function in heart failure with reduced ejection fraction and coronary artery disease.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): EU Framework Programme 7 Table 1

Scanning Thermal Microscopy and Ballistic Phonon Transport in Lateral Spin Valves

Using scanning thermal microscopy, we have mapped the spatial distribution of temperatures in an operating nanoscale device formed from a magnetic injector, an Ag connecting wire, and a magnetic detector. An analytical model explained the thermal diffusion over the measured temperature range (2-300 K) and injector-detector separation (400-3000 nm). The characteristic diffusion lengths of the Peltier and Joule heat differ remarkably below 60 K, a fact that can be explained by the onset of ballistic phonon heat transfer in the substrate.

Validation of histological and visual scoring systems for foot-pad dermatitis in broiler chickens

In this study, an appropriate visual scoring system for foot-pad dermatitis was validated, considering the histologically measured depth of the inflammation zone and the histopathological grade (no lesion, mild lesion, ulcer). The aim being to evaluate whether the visual, macroscopic scoring of foot-pad dermatitis can represent the histological, microscopic findings. Two hundred Ross 308 broiler chicken feet (birds aged 39–42 fattening days) were collected at a slaughterhouse and scored macroscopically according to a modified version of the Welfare Quality® Assessment Protocol for Poultry. Afterwards, 200 histological slides (one per foot) were prepared, the extent of the inflammation measured and all slides scored by veterinarian pathologists using Michel et al's modified scheme. The statistical relationship between microscopic and macroscopic score and depth of inflammation were estimated via regression models. Increasing macroscopic score was found to be linked with an increase in microscopic score and the depth of inflammation. In particular, feet without lesions and feet with ulcers were identifiable using the macroscopic score. Macroscopic scoring of foot-pad dermatitis can mirror histological findings once certain limitations are taken into account (superficial lesions were not clearly identifiable). Foot-pad dermatitis is considered a useful indicator of animal welfare and our findings suggest that visual, macroscopic scoring could be a practicable assessment tool.

Histologically validated scoring system for the assessment of hock burn in broilers

The assessment of bird-based welfare indicators plays an important role in the evaluation of bird welfare. The aim of the study was to histologically validate a visual scoring system for hock burn in broilers and to detect threshold values of a visual score to define welfare-relevant alterations in terms of mild lesions or ulcers of the hock. We collected 200 hocks of 39- to 42-day-old Ross 308 broilers after the slaughter process. Each hock was scored visually ("macro scores" 0-4) and evaluated histologically ("micro scores" 0-3), with high scores representing more severe lesions. Although we found a tendency for higher micro scores with increasing macro scores, an exact allocation of macro to micro scores was not possible. For example, macro score 1 could represent micro scores 1, 2 and 3, whereas macro scores 3 and 4 always represented micro score 3 (ulcer). The conditional probability of certain micro scores for given macro scores was estimated using a multinomial logistic regression model. Ulcer showed the highest probability at macro score 1, whereas mild lesions were not found to have an estimated highest probability at any macro score. The depth of inflammation of hock burn lesions increased with increasing macro scores up to macro score 3 with an average depth of 1019 µm. Visually more severe and deeper lesions were also histologically rated with higher scores. Thus, considering limitations, the herein validated macroscopic assessment scheme for hock burn allows an estimation of histological alterations in hocks of broilers.RESEARCH HIGHLIGHTS Histological validation of a visual assessment scheme for hock burn in broilers.Tendency for higher micro scores with increasing macro scores.Estimation of histological score via macro score possible with limitations.Histological depth of inflammation increased with an increasing macro score.

Odontogene Tumoren bei Hund und Katze

Gegenstand und Ziel: Odontogene Tumoren kommen bei Hund und Katze, wie auch bei den übrigen Haustierarten und beim Menschen, selten vor und können schwer zu diagnostizieren sein. In der vorliegenden Studie wurde eine größere Anzahl odontogener Tumoren von Hund und Katze histopathologisch untersucht und klassifiziert mit dem Ziel, eine verlässliche Grundlage für die Diagnostik dieser Tumoren zu schaffen. Material und Methoden: In der retrospektiven Studie wurden von 1390 kaninen und 317 felinen oralen Tumoren aus den Jahren 1977 bis 2007 die odontogenen Neoplasien selektiert, histopathologisch charakterisiert und anhand der aktuellen human-und veterinärmedizinischen WHO-(World Health Organization) Klassifikationen odontogener Tumoren (2005 bzw. 2003) eingeteilt. Ergebnisse: 18% (n = 250) der kaninen und 3,2% (n = 10) der felinen oralen Tumoren erwiesen sich als odontogen. Sie ließen sich in benigne (epitheliale, epitheliale und ektomesenchymale sowie ektomesenchymale) und maligne odontogene Tumoren (Karzinome und Sarkome) mit insgesamt 12 Entitäten unterteilen. Sowohl beim Hund wie auch bei der Katze war das odontogene Fibrom der am häufigsten diagnostizierte Tumor (n = 167 bzw. n = 4). An zweiter Stelle folgte beim Hund das Ameloblastom (n = 74), bei der Katze das ameloblastische Fibrom (n = 2). Vier der 12 Entitäten konnten anhand beider, sieben lediglich anhand der human-, zwei lediglich anhand der veterinärmedizinischen WHO-Klassifikation klassifiziert werden. Schlussfolgerung und klinische Relevanz: Die prognostische Bewertung von Tumorerkrankungen ist von größter klinischer Relevanz und setzt eine eindeutige Diagnose voraus. Insbesondere bei seltenen und histomorphologisch komplexen odontogenen Tumoren genügt die aktuelle veterinärmedizinische WHO-Klassifikation diesem Anspruch nicht und bedarf einer Überarbeitung und Erweiterung. Wirkungsvoller im Einsatz erwies sich die humanmedizinische WHO-Klassifikation.

Magnetic damping: domain wall dynamics versus local ferromagnetic resonance

Magnetic relaxation is one of the dominating features of magnetization dynamics. Depending on the magnetic structure and the experimental approach, different magnitudes of the damping parameter are reported even for a given material. In this study, we experimentally address this issue by accessing the damping parameter in the same magnetic nanotracks using different approaches: local ferromagnetic resonance (α=0.0072) and field-driven domain wall dynamics (α=0.023). The experimental results cannot fully be accounted for by modeling only roughness in micromagnetic simulations. Consequently, we have included nonlocal texture induced damping to the micromagnetic code. We find excellent agreement with the observed increased damping in the vortex structures for the same input Gilbert alpha when texture-induced nonlocal damping is included.

Type 2 diabetes from pediatric to geriatric age: analysis of gender and obesity among 120,183 patients from the German/Austrian DPV database

AIM

To characterize the clinical phenotype of type 2 diabetes mellitus (T2DM) with respect to age, gender, and BMI.

METHOD

Anonymized data of 120,183 people with T2DM from the German/Austrian multicenter Diabetes Patienten Verlaufsdokumentation database were analyzed based on chronological age or age at diagnosis (0-19, 20-39, 40-59, 60-79, and ≥80 years). Age, gender, and BMI comparisons with clinical phenotype were made using χ(2) and Kruskal-Wallis tests (SAS V9.2).

RESULTS

Of all the patients, 51.3% were male, average age was 67.112.7 years, and average disease duration was 9.99.1 years. More girls than boys were diagnosed during adolescence and more men than women during adulthood (2060 years). No gender differences existed when age at diagnosis was 60 years. Patients were obese on average (BMI: 30.5±6.1 kg/m(2)) and had significantly higher BMI values than German population peers. The BMI gap was widest in the younger age categories and closed with increasing age. Adult women were significantly more obese than men. Obese patients more often had elevated HbA1c (≥7.5%), hypertension or dyslipidemia (irrespective of age), microalbuminuria (adults), or retinopathy (elderly) than nonobese patients. More men than women (20-60 years) had hypertension, dyslipidemia, or microalbuminuria while more women than men (≥60 years) had hypertension or dyslipidemia.

CONCLUSION

During puberty, more girls than boys were diagnosed with T2DM while during adulthood males predominated. T2DM manifested at comparatively lower BMI in males, and younger patients were more obese at diagnosis. Age, gender, and BMI were also associated with poor metabolic control and cardiovascular disease comorbidities/complications.

High Estradiol Levels are Associated with Increased Mortality in Older Men Referred to Coronary Angiography

There is evidence showing an important role of estrogens in men’s health. We aimed to evaluate whether estradiol levels are associated with overall mortality and specific fatal events.

We measured estradiol levels in 2 078 men who were routinely referred for coronary angiography (1997–2000).

The main outcome measures were Cox proportional hazard ratios (HRs) for mortality from all causes, from cardiovascular and non-cardiovascular causes including cancer according to estradiol levels.

Multivariable HRs (with 95% confidence intervals) for all-cause, non-cardiovascular, and cancer mortality were 1.43 (1.08–1.91), 2.11 (1.34–3.34), and 2.27 (1.00–5.19), respectively, in the fourth estradiol quartile as compared to the first. There was no significant association of estradiol levels with cardiovascular mortality. In multivariate adjusted analyses, higher estradiol levels in men were significantly associated with prevalent strokes, peripheral vascular disease, and carotid artery stenosis compared to lower estradiol levels.

High levels of estradiol are associated with all-cause and non-cardiovascular mortality in a large cohort of older men referred to coronary angiography. Further studies are warranted to confirm our results and to elucidate the underlying mechanisms.

[Odontogenic tumours in the dog and cat]

OBJECTIVE

Odontogenic tumours in the dog and cat, as well as in other domestic animals and in man occur rarely and can be difficult to diagnose. In the present study a great number of canine and feline odontogenic tumours were investigated histopathologically and classified to provide an appropriate basis for the evaluation of these tumours.

MATERIAL AND METHODS

In a retrospective study of a total of 1390 canine and 317 feline oral tumours from the years 1977 to 2007, the tumours of odontogenic origin were selected, characterized histopathologically and classified according to the current human WHO-classification of odontogenic tumours (2005) and the current veterinary WHO-classification of odontogenic tumours (2003).

RESULTS

18% (n=250) of the canine and 3.2% (n=10) of the feline oral tumours proved to be of odontogenic origin. They could be divided into benign (epithelial, epithelial and ectomesenchymal, ectomesenchymal) and malignant (carcinomas and sarcomas) odontogenic tumours with a total of 12 different entities. The odontogenic fibroma was the most common canine (n=167) and feline (n=4) odontogenic tumour. The second most common odontogenic tumour for canines was ameloblastoma (n=74) and that for felines was ameloblastic fibroma (n=2). Four of the 12 entities could be classified according to both WHO-classifications of odontogenic tumours. Seven and two of the 12 entities could only be classified according to the current human WHO-classification and veterinary WHO-classification, respectively.

CONCLUSION AND CLINICAL RELEVANCE

The prognostic evaluation of tumours is of the greatest clinical relevance and calls for an absolutely certain diagnosis. Particularly in the case of the rare and histomorphologically complex odontogenic tumours the current veterinary WHO-classification does not meet this requirement and needs to be revised and extended. The human WHO-classification proved to be more efficient when compared to the veterinary one.

No association of the IRS1 and PAX4 genes with type I diabetes

To reassess earlier suggested type I diabetes (T1D) associations of the insulin receptor substrate 1 (IRS1) and the paired domain 4 gene (PAX4) genes, the Type I Diabetes Genetics Consortium (T1DGC) evaluated single-nucleotide polymorphisms (SNPs) covering the two genomic regions. Sixteen SNPs were evaluated for IRS1 and 10 for PAX4. Both genes are biological candidate genes for T1D. Genotyping was performed in 2300 T1D families on both Illumina and Sequenom genotyping platforms. Data quality and concordance between the platforms were assessed for each SNP. Transmission disequilibrium testing neither show T1D association of SNPs in the two genes, nor did haplotype analysis. In conclusion, the earlier suggested associations of IRS1 and PAX4 to T1D were not supported, suggesting that they may have been false positive results. This highlights the importance of thorough quality control, selection of tagging SNPs, more than one genotyping platform in high throughput studies, and sufficient power to draw solid conclusions in genetic studies of human complex diseases.

Bones and Crohn's: estradiol deficiency in men with Crohn's disease is not associated with reduced bone mineral density

Background

Reduced bone mineral density (BMD) and osteoporosis are frequent in Crohn's disease (CD), but the underlying mechanisms are still not fully understood. Deficiency of sex steroids, especially estradiol (E2), is an established risk factor in postmenopausal osteoporosis.

Aim

To assess if hormonal deficiencies in male CD patients are frequent we investigated both, sex steroids, bone density and bone metabolism markers.

Methods

111 male CD patients underwent osteodensitometry (DXA) of the spine (L1–L4). Disease related data were recorded. Disease activity was estimated using Crohn's disease activity index (CDAI). Testosterone (T), dihydrotestosterone (DHT), estradiol (E2), sex hormone binding globulin (SHBG), Osteocalcin and carboxyterminal cross-linked telopeptids (ICTP) were measured in 111 patients and 99 age-matched controls.

Results

Patients had lower T, E2 and SHBG serum levels (p < 0.001) compared to age-matched controls. E2 deficiency was seen in 30 (27.0%) and T deficiency in 3 (2.7%) patients but only in 5 (5.1%) and 1 (1%) controls. Patients with E2 deficiency had significantly decreased T and DHT serum levels. Use of corticosteroids for 3 of 12 months was associated with lower E2 levels (p < 0.05). Patients with life-time steroids >10 g had lower BMD. 32 (28.8%) patients showed osteoporosis, 55 (49.5%) osteopenia and 24 (21.6%) had normal BMD. Patients with normal or decreased BMD showed no significant difference in their hormonal status. No correlation between markers of bone turnover and sex steroids could be found. ICTP was increased in CD patients (p < 0.001), and patients with osteoporosis had higher ICTP levels than those with normal BMD.

Conclusion

We found an altered hormonal status – i.e. E2 and, to a lesser extent T deficiency – in male CD patients but failed to show an association to bone density or markers of bone turnover. The role of E2 in the negative skeletal balance in males with CD, analogous to E2 deficiency in postmenopausal females, deserves further attention.

Association of childhood type 1 diabetes mellitus with a variant of PAX4: possible link to beta cell regenerative capacity

AIMS/HYPOTHESIS

Loss of pancreatic beta cells is the crucial event in the development of type 1 diabetes. It is the result of an imbalance between autoimmune destruction and insufficient regeneration of islet cells. To study the role of islet cell regeneration in the pathogenesis of type 1 diabetes, we focused on PAX4, a paired homeodomain transcriptional repressor that is involved in islet cell growth.

METHODS

The study included 379 diabetic children and 1,070 controls from two distinct populations, and a cohort of children who had not developed type 1 diabetes, despite the presence of islet cell antibodies. Genomic DNA analysis of PAX4 was carried out via direct sequencing of PCR-amplified fragments and allelic discrimination. We compared the transrepression potential of the PAX4 variants in betaTC3 cells and analysed their influence on beta cell growth.

RESULTS

The type 1 diabetic subjects are different from the normal individuals in terms of the genotype distribution of the A1168C single nucleotide polymorphism in PAX4. The C/C genotype is frequent among type 1 diabetic children (73%) and rare among the control population (32%). Conversely, the A/C genotype is prevalent among control subjects (62%) and antibody-positive children without type 1 diabetes (73.6%), but uncommon among subjects with type 1 diabetes (17.5%). The combination of PAX4A and PAX4C is functionally more active than PAX4C alone (the "diabetic" variant). Beta cells expressing PAX4A and PAX4C efficiently proliferate when stimulated with glucose, whereas cells expressing the PAX4C variant alone do not.

CONCLUSIONS/INTERPRETATION

We have identified a link between beta cell regenerative capacity and susceptibility to type 1 diabetes. This finding could explain the fact that not all of the individuals who develop autoimmunity against beta cells actually contract the disease. The C/C genotype of the A1168C polymorphism in PAX4 can be viewed as a predisposition marker that can help to detect individuals prone to develop type 1 diabetes.

Technical mishaps as easily avoidable causes of treatment failure when using pumps for pulsatile administration of gonadotropin-releasing hormone

A patient (19 years old) with Kallmann's syndrome was treated with gonadotropin-releasing hormone (2.5-16 micrograms) administered subcutaneously every 2 h using a portable infusion pump. During 42 weeks of treatment testosterone levels and testicular size did not increase sufficiently although no reasons for this insufficient response were detectable. Therefore the regime of controlling and changing the catheter system was intensified. By this means partial occlusions of the catheter were detected and could be corrected. Afterwards testosterone levels increased immediately and persistently to normal values.