Benign paroxysmal positional vertigo in mountain bikers

We evaluated 4 men who had benign paroxysmal positional vertigo (BPPV) that occured several hours after intensive mountain biking but without head trauma. The positional maneuvers in the planes of the posterior and horizontal canals elicited BPPV, as well as transitory nystagmus. This was attributed to both the posterior and horizontal semicircular canals (SCCs) on the left side in 1 patient, in these 2 SCCs on the right side in another patient, and to the right posterior SCC in the other 2 patients. The symptoms disappeared after physiotherapeutic maneuvers in 2 patients and spontaneously in the other 2 patients. Cross-country or downhill mountain biking generates frequent vibratory impacts, which are only partially filtered through the suspension fork and the upper parts of the body. Biomechanically, during a moderate jump, before landing, the head is subjected to an acceleration close to negative 1 g, and during impact it is subjected to an upward acceleration of more than 2g. Repeated acceleration-deceleration events during intensive off-road biking might generate displacement and/or dislocation of otoconia from the otolithic organs, inducing the typical symptoms of BPPV. This new cause of posttraumatic BPPV should be considered as an injury of minor severity attributed to the practice of mountain biking.

Large genomic fibrillin-1 (FBN1) gene deletions provide evidence for true haploinsufficiency in Marfan syndrome

Mutations in the FBN1 gene are the major cause of Marfan syndrome (MFS), an autosomal dominant connective tissue disorder, which displays variable manifestations in the cardiovascular, ocular, and skeletal systems. Current molecular genetic testing of FBN1 may miss mutations in the promoter region or in other noncoding sequences as well as partial or complete gene deletions and duplications. In this study, we tested for copy number variations by successively applying multiplex ligation-dependent probe amplification (MLPA) and the Affymetrix Human Mapping 500 K Array Set, which contains probes for approximately 500,000 single-nucleotide polymorphisms (SNPs) across the genome. By analyzing genomic DNA of 101 unrelated individuals with MFS or related phenotypes in whom standard genetic testing detected no mutation, we identified FBN1 deletions in two patients with MFS. Our high-resolution approach narrowed down the deletion breakpoints. Subsequent sequencing of the junctional fragments revealed the deletion sizes of 26,887 and 302,580 bp, respectively. Surprisingly, both deletions affect the putative regulatory and promoter region of the FBN1 gene, strongly indicating that they abolish transcription of the deleted allele. This expectation of complete loss of function of one allele, i.e. true haploinsufficiency, was confirmed by transcript analyses. Our findings not only emphasize the importance of screening for large genomic rearrangements in comprehensive genetic testing of FBN1 but, importantly, also extend the molecular etiology of MFS by providing hitherto unreported evidence that true haploinsufficiency is sufficient to cause MFS.

Clustering of HCV coinfections on HIV phylogeny indicates domestic and sexual transmission of HCV

BACKGROUND: HCV coinfection remains a major cause of morbidity and mortality among HIV-infected individuals and its incidence has increased dramatically in HIV-infected men who have sex with men(MSM). METHODS: Hepatitis C virus (HCV) coinfection in the Swiss HIV Cohort Study(SHCS) was studied by combining clinical data with HIV-1 pol-sequences from the SHCS Drug Resistance Database(DRDB). We inferred maximum-likelihood phylogenetic trees, determined Swiss HIV-transmission pairs as monophyletic patient pairs, and then considered the distribution of HCV on those pairs. RESULTS: Among the 9748 patients in the SHCS-DRDB with known HCV status, 2768(28%) were HCV-positive. Focusing on subtype B(7644 patients), we identified 1555 potential HIV-1 transmission pairs. There, we found that, even after controlling for transmission group, calendar year, age and sex, the odds for an HCV coinfection were increased by an odds ratio (OR) of 3.2 [95% confidence interval (CI) 2.2, 4.7) if a patient clustered with another HCV-positive case. This strong association persisted if transmission groups of intravenous drug users (IDUs), MSMs and heterosexuals (HETs) were considered separately(in all cases OR >2). Finally we found that HCV incidence was increased by a hazard ratio of 2.1 (1.1, 3.8) for individuals paired with an HCV-positive partner. CONCLUSIONS: Patients whose HIV virus is closely related to the HIV virus of HIV/HCV-coinfected patients have a higher risk for carrying or acquiring HCV themselves. This indicates the occurrence of domestic and sexual HCV transmission and allows the identification of patients with a high HCV-infection risk.

Frailty and risk for heart failure in older adults: the health, aging, and body composition study

OBJECTIVE The aim of this study was to assess the association between frailty and risk for heart failure (HF) in older adults. BACKGROUND Frailty is common in the elderly and is associated with adverse health outcomes. Impact of frailty on HF risk is not known. METHODS We assessed the association between frailty, using the Health ABC Short Physical Performance Battery (HABC Battery) and the Gill index, and incident HF in 2825 participants aged 70 to 79 years. RESULTS Mean age of participants was 74 ± 3 years; 48% were men and 59% were white. During a median follow up of 11.4 (7.1-11.7) years, 466 participants developed HF. Compared to non-frail participants, moderate (HR 1.36, 95% CI 1.08-1.71) and severe frailty (HR 1.88, 95% CI 1.02-3.47) by Gill index was associated with a higher risk for HF. HABC Battery score was linearly associated with HF risk after adjusting for the Health ABC HF Model (HR 1.24, 95% CI 1.13-1.36 per SD decrease in score) and remained significant when controlled for death as a competing risk (HR 1.30; 95% CI 1.00-1.55). Results were comparable across age, sex, and race, and in sub-groups based on diabetes mellitus or cardiovascular disease at baseline. Addition of HABC Battery scores to the Health ABC HF Risk Model improved discrimination (change in C-index, 0.014; 95% CI 0.018-0.010) and appropriately reclassified 13.4% (net-reclassification-improvement 0.073, 95% CI 0.021-0.125; P = .006) of participants (8.3% who developed HF and 5.1% who did not). CONCLUSIONS Frailty is independently associated with risk of HF in older adults.

ARMin: a robot for patient-cooperative arm therapy

Task-oriented, repetitive and intensive arm training can enhance arm rehabilitation in patients with paralyzed upper extremities due to lesions of the central nervous system. There is evidence that the training duration is a key factor for the therapy progress. Robot-supported therapy can improve the rehabilitation allowing more intensive training. This paper presents the kinematics, the control and the therapy modes of the arm therapy robot ARMin. It is a haptic display with semi-exoskeleton kinematics with four active and two passive degrees of freedom. Equipped with position, force and torque sensors the device can deliver patient-cooperative arm therapy taking into account the activity of the patient and supporting him/her only as much as needed. The haptic display is combined with an audiovisual display that is used to present the movement and the movement task to the patient. It is assumed that the patient-cooperative therapy approach combined with a multimodal display can increase the patient's motivation and activity and, therefore, the therapeutic progress.

Die 68er. Kurzer Sommer – lange Wirkung

Als Beitrag zur heutigen politischen und gesellschaftlichen Selbstreflexion bietet der Katalog zur gleichnamigen Ausstellung im Historischen Museum in Frankfurt am Main einen thematischen Rückblick auf das bewegte Jahr 1968 und diskutiert die seitherigen Veränderungen.

Thrombus imaging in acute stroke: correlation of thrombus length on susceptibility-weighted imaging with endovascular reperfusion success

OBJECTIVES Susceptibility-weighted imaging (SWI) enables visualization of thrombotic material in acute ischemic stroke. We aimed to validate the accuracy of thrombus depiction on SWI compared to time-of-flight MRA (TOF-MRA), first-pass gadolinium-enhanced MRA (GE-MRA) and digital subtraction angiography (DSA). Furthermore, we analysed the impact of thrombus length on reperfusion success with endovascular therapy. METHODS Consecutive patients with acute ischemic stroke due to middle cerebral artery (MCA) occlusions undergoing endovascular recanalization were screened. Only patients with a pretreatment SWI were included. Thrombus visibility and location on SWI were compared to those on TOF-MRA, GE-MRA and DSA. The association between thrombus length on SWI and reperfusion success was studied. RESULTS Eighty-four of the 88 patients included (95.5 %) showed an MCA thrombus on SWI. Strong correlations between thrombus location on SWI and that on TOF-MRA (Pearson's correlation coefficient 0.918, P < 0.001), GE-MRA (0.887, P < 0.001) and DSA (0.841, P < 0.001) were observed. Successful reperfusion was not significantly related to thrombus length on SWI (P = 0.153; binary logistic regression). CONCLUSIONS In MCA occlusion thrombus location as seen on SWI correlates well with angiographic findings. In contrast to intravenous thrombolysis, thrombus length appears to have no impact on reperfusion success of endovascular therapy. KEY POINTS • SWI helps in assessing location and length of thrombi in the MCA • SWI, MRA and DSA are equivalent in detecting the MCA occlusion site • SWI is superior in identifying the distal end of the thrombus • Stent retrievers should be deployed over the distal thrombus end • Thrombus length did not affect success of endovascular reperfusion guided by SWI.

Temperature reconstruction from 10 to 120 kyr b2k from the NGRIP ice core

In order to reconstruct the temperature of the North Greenland Ice Core Project (NGRIP) site, new measurements of δ15N have been performed covering the time period from the beginning of the Holocene to Dansgaard–Oeschger (DO) event 8. Together with previously measured and mostly published δ15N data, we present for the first time a NGRIP temperature reconstruction for the whole last glacial period from 10 to 120 kyr b2k (thousand years before 2000 AD) including every DO event based on δ15N isotope measurements combined with a firn densification and heat diffusion model. The detected temperature rises at the onset of DO events range from 5 °C (DO 25) up to 16.5 °C (DO 11) with an uncertainty of ±3 °C. To bring measured and modelled data into agreement, we had to reduce the accumulation rate given by the NGRIP ss09sea06bm timescale in some periods by 30 to 35%, especially during the last glacial maximum. A comparison between reconstructed temperature and δ18Oice data confirms that the isotopic composition of the stadial was strongly influenced by seasonality. We evidence an anticorrelation between the variations of the δ18Oice sensitivity to temperature (referred to as α) and obliquity in agreement with a simple Rayleigh distillation model. Finally, we suggest that α might be influenced by the Northern Hemisphere ice sheet volume.

Up, down, strange and charm quark masses with Nf = 2+1+1 twisted mass lattice QCD

We present a lattice QCD calculation of the up, down, strange and charm quark masses performed using the gauge configurations produced by the European Twisted Mass Collaboration with Nf=2+1+1 dynamical quarks, which include in the sea, besides two light mass degenerate quarks, also the strange and charm quarks with masses close to their physical values. The simulations are based on a unitary setup for the two light quarks and on a mixed action approach for the strange and charm quarks. The analysis uses data at three values of the lattice spacing and pion masses in the range 210–450 MeV, allowing for accurate continuum limit and controlled chiral extrapolation. The quark mass renormalization is carried out non-perturbatively using the RI′-MOM method. The results for the quark masses converted to the scheme are: mud(2 GeV)=3.70(17) MeV, ms(2 GeV)=99.6(4.3) MeV and mc(mc)=1.348(46) GeV. We obtain also the quark mass ratios ms/mud=26.66(32) and mc/ms=11.62(16). By studying the mass splitting between the neutral and charged kaons and using available lattice results for the electromagnetic contributions, we evaluate mu/md=0.470(56), leading to mu=2.36(24) MeV and md=5.03(26) MeV.

Suppressing versus releasing a habit: frequency-dependent effects of prefrontal transcranial magnetic stimulation.

When subjects are required to generate a random sequence of numbers they typically produce too many forward and backward 'counts' (e.g. 5-6, 4-3). This counting bias is interpreted as the consequence of an interference by overlearned tendencies to arrange numbers according to their natural order. Inhibition of such well-learned routines is known to rely on frontal lobe functioning. We examined differential effects of slow (1 Hz) and fast (10 Hz) repetitive transcranial magnetic stimulation (rTMS) over the left or right dorsolateral prefrontal cortex (DLPFC) on random number generation (RNG) performance. Eighteen healthy men performed an RNG task. Those subjects stimulated over the left DLPFC showed a frequency-dependent rTMS effect: counting bias was significantly reduced after the 1 Hz stimulation compared with baseline, but significantly exaggerated after the 10 Hz stimulation compared with 1 Hz stimulation. In contrast, the sequences of the subjects stimulated over the right DLPFC showed the well-known excess of counting in all conditions (i.e. baseline, 1 Hz and 10 Hz). These findings confirm the functional importance of specifically the left DLPFC in sequential response production and show, for the first time, that rTMS affects cognitive processing in a frequency-dependent manner.

Correlation between serum total globulins and gamma globulins and their use to diagnose failure of passive transfer in foals.

Various assays have been used as an aid to diagnose failure of passive transfer (FPT) of immunoglobulins in neonatal foals, but often lack sensitivity as screening tests, or are time consuming to perform and impractical as confirmatory tests. The aim of the present study was to evaluate whether measurement of serum total globulins (TG; i.e. total protein minus albumin) can be used to estimate the electrophoretic gamma globulin (EGG) fraction in hospitalised neonatal foals with suspected FPT. Sample data from 56 foals were evaluated retrospectively. The coefficient of rank correlation was 0.84. The area under the curve of ROC analysis was 0.887, 0.922 and 0.930 for EGG concentrations <2 g/L, < 4 g/L and <8 g/L, respectively. Cut-offs for TG achieved ≥90% sensitivity for detecting EGG <2 g/L, < 4 g/L and <8 g/L, with negative predictive values of >97% and >94%, using prevalence of 15% and 30%, respectively. These results suggest that measurement of TG can be used as a guide to predicting EGG, provided that appropriate cut-off values are selected, and this technique could be a useful initial screening test for FPT in foals.