The SUN Protein Mps3 Is Required for Spindle Pole Body Insertion into the Nuclear Membrane and Nuclear Envelope Homeostasis

The budding yeast spindle pole body (SPB) is anchored in the nuclear envelope so that it can simultaneously nucleate both nuclear and cytoplasmic microtubules. During SPB duplication, the newly formed SPB is inserted into the nuclear membrane. The mechanism of SPB insertion is poorly understood but likely involves the action of integral membrane proteins to mediate changes in the nuclear envelope itself, such as fusion of the inner and outer nuclear membranes. Analysis of the functional domains of the budding yeast SUN protein and SPB component Mps3 revealed that most regions are not essential for growth or SPB duplication under wild-type conditions. However, a novel dominant allele in the P-loop region, MPS3-G186K, displays defects in multiple steps in SPB duplication, including SPB insertion, indicating a previously unknown role for Mps3 in this step of SPB assembly. Characterization of the MPS3-G186K mutant by electron microscopy revealed severe over-proliferation of the inner nuclear membrane, which could be rescued by altering the characteristics of the nuclear envelope using both chemical and genetic methods. Lipid profiling revealed that cells lacking MPS3 contain abnormal amounts of certain types of polar and neutral lipids, and deletion or mutation of MPS3 can suppress growth defects associated with inhibition of sterol biosynthesis, suggesting that Mps3 directly affects lipid homeostasis. Therefore, we propose that Mps3 facilitates insertion of SPBs in the nuclear membrane by modulating nuclear envelope composition

Inventory of current EU paediatric vision and hearing screening programmes

Background: We examined the diversity in paediatric vision and hearing screening programmes in Europe. Methods: Themes relevant for comparison of screening programmes were derived from literature and used to compile three questionnaires on vision, hearing and public-health screening. Tests used, professions involved, age and frequency of testing seem to influence sensitivity, specificity and costs most. Questionnaires were sent to ophthalmologists, orthoptists, otolaryngologists and audiologists involved in paediatric screening in all EU fullmember, candidate and associate states. Answers were cross-checked. Results: Thirty-nine countries participated; 35 have a vision screening programme, 33 a nation-wide neonatal hearing screening programme. Visual acuity (VA) is measured in 35 countries, in 71% more than once. First measurement of VA varies from three to seven years of age, but is usually before the age of five. At age three and four picture charts, including Lea Hyvarinen are used most, in children over four Tumbling-E and Snellen. As first hearing screening test otoacoustic emission (OAE) is used most in healthy neonates, and auditory brainstem response (ABR) in premature newborns. The majority of hearing testing programmes are staged; children are referred after one to four abnormal tests. Vision screening is performed mostly by paediatricians, ophthalmologists or nurses. Funding is mostly by health insurance or state. Coverage was reported as >95% in half of countries, but reporting was often not first-hand. Conclusion: Largest differences were found in VA charts used (12), professions involved in vision screening (10), number of hearing screening tests before referral (1-4) and funding sources (8)

Individualized Treatment Patterns for Patients with Narcolepsy Treated with Oxybate: A Clinical Practice Perspective

Asim Roy,1 Diane Ito,2 Susan Morris,3 Shawn Candler,4 Judi Profant,3 Charles Bae5 1Ohio Sleep Medicine Institute, Dublin, OH, USA; 2Stratevi LLC, Santa Monica, CA, USA; 3Jazz Pharmaceuticals, Palo Alto, CA, USA; 4Jazz Pharmaceuticals, Philadelphia, PA, USA; 5Penn Sleep Center, University of Pennsylvania, Philadelphia, PA, USACorrespondence: Asim Roy, Ohio Sleep Medicine Institute, 4975 Bradenton Avenue, Dublin, OH, 43017, USA, Tel +1 614-766-0773, Fax +1 614-766-2599, Email [email protected]: Real-world data regarding divided nightly dosing of oxybate and individualized prescribing in patients with narcolepsy are limited. Study objectives were to understand oxybate prescribing practices, including optimizing dose regimens and adjusting dosing per occasional changes in patients’ routines, and physician recommendations for representative patient scenarios.Patients and Methods: A cross-sectional, web- and audio-based survey of physicians treating ≥ 2 patients with narcolepsy, prescribed nightly oxybate (sodium oxybate) dosing for ≥ 6 months, was conducted. Physicians were surveyed on patients’ usual oxybate dosing regimens, frequency of and reasons for oxybate dosing-related discussions, and preferred methods for and perceptions of adjusting oxybate dosing. Physicians provided dosing-related guidance for 4 representative scenarios.Results: Participating physicians (N=25) were neurologists (52%), psychiatrists (44%), and neuropsychiatrists (4%). Individualized oxybate prescribing practices were reflected by the variability of physicians’ reporting of the percentage of their patients being prescribed once-nightly, twice-nightly, and thrice-nightly dosing regimens. Most physicians (68%) reported discussing adjusting individualized treatment to accommodate occasional changes to patients’ routines; the most common reasons were consuming contraindicated beverages (alcohol; 65%) and travel (59%). Adjusting total nightly dose (68%) and dose timing (68%) were preferred adjustment methods. Most physicians (88%) felt the ability to individualize oxybate dosing was important and had a positive impact on ability to provide care. For each representative scenario, physicians provided several dose-adjustment recommendations, and physician responses encouraged patient participation in treatment decision-making.Conclusion: Physicians provided guidance supportive of oxybate dose adjustments to accommodate occasional changes in patients’ routines, and perceived individualized dosing as important in providing care.Plain Language Summary: Why was the research needed?Narcolepsy is an uncommon condition that causes individuals to feel sleepy throughout the day. Other symptoms may include sudden muscle weakness. There is no cure for narcolepsy, but there are several treatments, including medicines known as oxybates. This study focused on how doctors use oxybate to treat patients with narcolepsy.How was the research done?This study was an online survey of doctors who were treating 2 or more patients with narcolepsy. Patients had been taking oxybate for at least 6 months. The survey asked doctors about their patients’ normal oxybate usage, how often and why they discussed oxybate treatment, and which ways oxybate treatment was usually adjusted.What are the results?Twenty-five doctors took part in this study. Most doctors said they discuss personalized treatment to help with occasional changes in their patients’ daily lives. The most common reasons for making treatment changes were consuming alcohol and travel. The most common changes were total nightly amount and timing of oxybate. Most doctors said the ability to personalize oxybate treatment is important and has a positive impact.What does the research mean?This study provides valuable knowledge on real-world oxybate treatment patterns and the conditions when doctors make clinical decisions about treating patients with narcolepsy.Graphical Abstract: Keywords: sodium oxybate, low-sodium oxybate, calcium, magnesium, potassium, sodium oxybates, prescribing patterns, personalized dosin

Screening for GJB2 and GJB6 mutations in the Slovak deaf population

Introduction: Mutations of connexin genes account for up to 50% of prelingual bilateral sensorineural hearing loss (SNHL). In Slovakia the deaf population is estimated to reach about 9000 individuals. However, reliable data on bilateral SNHL etiology in Slovakia are not available to date. The aim of presented study was to analyze the GJB2 and GJB6 genes and describe their mutation spectrum in patients with bilateral SNHL and thus to determine epidemiology of one of the most dominant causes of SNHL in Slovakia. Methods: Since 2010 we performed molecular-genetic testing for GJB2 and GJB6 mutations in >500 subjects suffering from bilateral SNHL, that included 375 unrelated individuals selected for epidemiology analyses. Patients were recruited at 2 ORL clinics in Bratislava and special schools for hearing impaired children throughout Slovakia. Inclusion criteria were bilateral SNHL and age below 60 years at the time of hearing loss diagnosis. Direct sequencing and MLPA was used for DNA analysis. Results: We identified 11 mutations and six polymorphisms in GJB2 gene. Homozygous mutations occurred in 22% and compound heterozygotes in 9% of subjects. Negative subjects, without any pathogenic allele found accounted for 61%. Mutations c.35delG and c.71G>A were recorded most frequently (60.4% and 15.8% respectively). The large GJB6 deletion (delD13S1830) was found in 1 family.Conclusions: DNA analysis of patients with SNHL revealed mutation spectrum of GJB2 and GJB6 genes in our cohort and also confirmed exact genetic cause of hearing loss in almost one third of investigated subjects. Our results represent fundamental data for genetic counseling, clinical prognosis, improvement of diagnostic tools for clinical practice and possible personalized treatment in future.Supported by: Grants APVV 0148-10 and VEGA 1/0465/11Der Erstautor gibt keinen Interessenkonflikt an