Three-Dimensional Electronic Structure of the Type-II Weyl Semimetal WTe_{2}.

By combining bulk sensitive soft-x-ray angular-resolved photoemission spectroscopy and first-principles calculations we explored the bulk electron states of WTe_{2}, a candidate type-II Weyl semimetal featuring a large nonsaturating magnetoresistance. Despite the layered geometry suggesting a two-dimensional electronic structure, we directly observe a three-dimensional electronic dispersion. We report a band dispersion in the reciprocal direction perpendicular to the layers, implying that electrons can also travel coherently when crossing from one layer to the other. The measured Fermi surface is characterized by two well-separated electron and hole pockets at either side of the Γ point, differently from previous more surface sensitive angle-resolved photoemission spectroscopy experiments that additionally found a pronounced quasiparticle weight at the zone center. Moreover, we observe a significant sensitivity of the bulk electronic structure of WTe_{2} around the Fermi level to electronic correlations and renormalizations due to self-energy effects, previously neglected in first-principles descriptions.

Screening for congenital hearing impairment with brainstem evoked response audiometry in isolated orofacial cleft.

Brainstem evoked response audiometry (BERA) is the most established and recommended objective audiometric method for the clinical diagnosis of hearing impairment in high-risk infants. It is unclear whether infants with orofacial clefts meet the criteria for the high-risk group. This retrospective cohort study evaluated the need for diagnostic BERA in infants with cleft palate with or without cleft lip by assessing the predisposition to and diagnosis of congenital hearing impairment. Data from 122 patients treated at a single cleft centre were evaluated. BERA was conducted at the time of palate repair at 4-6 months of age. Clinical follow-up was analysed up to 4 years. The presence of a syndrome was examined as a risk factor for congenital hearing impairment. Among the 122 patients, four had congenital sensorineural or mixed hearing loss requiring hearing aids. All affected patients had syndromes in addition to the cleft. Most patients with elevated hearing thresholds had transient conductive hearing loss. Most suspected sensorineural hearing loss initially diagnosed was refuted. However, a higher incidence of sensorineural hearing loss was found in patients with syndromic clefts, supporting the diagnostic use of BERA with initial surgery only in patients with syndromic clefts.

Impact of MALDI-TOF-MS-based identification directly from positive blood cultures on patient management: a controlled clinical trial.

OBJECTIVES: Rapid identification of pathogens directly from positive blood cultures (BC) in combination with an antimicrobial stewardship programme (ASP) is associated with improved antibiotic treatment and outcomes, but the effect of each individual intervention is less clear. The current study investigated the impact of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) versus conventional identification on antibiotic management in a setting with a well-established ASP and low resistance rates. METHODS: In this single-centre open label, controlled clinical trial 425 patients with positive BCs were allocated by weekday during a 1-year period to either MALDI-TOF directly from positive BCs or conventional processing. ASP was identical throughout the study period. The primary outcome was duration of intravenous antimicrobial therapy and was analysed in an intention-to-treat approach. RESULTS: In all, 368 patients were analysed (MALDI-TOF n = 168; conventional n = 200) with similar baseline characteristics. Mean duration of intravenous antimicrobial therapy (12.9 versus 13.2 days, p 0.9) and length of stay (16.1 versus 17.9 days, p 0.3) were comparable. In the clinically significant bloodstream infection subgroup (n = 242) mean time from Gram-stain to active treatment was significantly shorter (3.7 versus 6.7 h, p 0.003). Admission to the intensive care unit after bloodstream infection onset was less frequent in the MALDI-TOF group (23.1 versus 37.2%, p 0.02). CONCLUSIONS: Rapid identification of contaminated BCs (n = 126) resulted in a shorter duration of intravenous antimicrobial therapy (mean 4.8 versus 7.5 days, p 0.04). Rapid identification using MALDI-TOF directly from positive BCs did not impact on duration of intravenous antimicrobial therapy, but provided fast and reliable microbiological results and may improve treatment quality in the setting of an established ASP.

[Clinical implications of molecular genetic research in otorhinolaryngology]. / Molekulargenetische Aspekte in der Otorhinolaryngologie.

Molecular-genetic research in Otolaryngology has seen a rapid advancement during the last ten years, especially in the fields of otology and head and neck tumors. The results of this basic research have now started to be implemented in the clinic. In otology the understanding of auditive function has dramatically improved. The syndromic and non-syndromic forms of hereditary hearing impairment can be subdivided into their underlying genetic defects, as more and more genes are identified. Diagnostic of syndromic hearing loss has been improved and can be done earlier. But the molecular-genetic analysis is still time-consuming and difficult. Currently, in our clinic, only patients with suspected Pendred-syndrome, representing the most frequent syndrome with hearing impairment, undergo a routine search for mutation detection in the corresponding gene SLC26A4. A multitude of genes and mutations are seen in the non-syndromic forms of hereditary hearing impairment. The gene gap-junction-protein beta2, encoding connexin 26, is encountered most frequently. Its prevalence in Switzerland is high with about 20% in the non-syndromic group. A molecular-genetic analysis of connexin 26 is offered in cases of congenital hearing loss. Another analysis, which has been implemented in the clinic, is the sequencing of Wolfram-syndrome gene 1 in familial low-frequency hearing loss. This gene seems to be involved in the majority of families with this type of hearing loss. Gene therapy for hearing loss is currently not an option in the clinical field. The different steps in carcinogenesis of head and neck cancer have further been elucidated by molecular-genetic research. Clinical applications are the establishment of risk-profiles for tumor-development and defining prognostic markers as well as the development of new treatment strategies based on genetic therapy.

Hearing loss and fluctuating hearing levels in X-linked hypophosphataemic osteomalacia.

BACKGROUND AND OBJECTIVE: X-linked hypophosphataemic osteomalacia is the most common of the genetically determined forms of osteomalacia. The occurrence of hearing loss in X-linked hypophosphataemic osteomalacia has been known since 1984. However, observations on the progression of such hearing loss, and suggestions regarding possible therapy, have not previously been published. METHODS: Case report of a patient with X-linked hypophosphataemic osteomalacia and hearing loss, with three years' audiological follow up, description of empirical therapy and literature review. RESULTS: The patient presented with fluctuating hearing. An audiogram showed mild to severe sensorineural hearing loss mainly in the low and high frequencies. A temporary improvement of 20-40 dB after steroid therapy was observed. Four weeks later, hearing had deteriorated again, mainly in the low frequencies. After one year of fluctuating hearing levels, stabilisation occurred. CONCLUSIONS: In X-linked hypophosphataemic osteomalacia, hearing loss occurs predominantly in the low and high frequencies. The hearing loss type and progression pattern point to an endolymphatic hydrops as the pathogenetic mechanism. Steroid therapy may be of some benefit.

Ultrasound-guided core-needle biopsy in the diagnosis of head and neck lesions.

This article describes the technique of ultrasound-guided core-needle biopsy in the head and neck, and also warns of its risks. In contrast to fine-needle aspiration, this minimally invasive procedure has the advantage of supplying a histological specimen rather than a cytological smear. Therefore, it could be used as an additional diagnostic tool in the investigation of head and neck lesions, and can be carried out within the out-patients clinic.

[Is there clinical evidence for the aging of the peripheral vestibular organ?]. / Ist die Alterung des peripheren vestibulären Organs klinisch nachweisbar?

The ageing process of hearing is well known. Age-dependent normative data are established for pure tone audiometry. It seems logical to suppose that the peripheral vestibular system undergoes a similar ageing process. To support this hypothesis we investigated subjects aged 50-82 with presbyacusis demonstrated by pure tone audiometry. Asymmetry of the peripheral vestibular system was ruled out by symmetrical thermal excitation rate. Slow-phase velocity of nystagmus induced by rotating-chair stimulation was compared with pure tone audiometry. We found no significant correlation and thus our approach failed to bear out the hypothesis.