45 research outputs found
Adult-Onset Ataxia with Neuropathy and White Matter Abnormalities Due to a Novel SAMD9L Variant
Variants in tumor suppressor genes and in genes encoding DNA repairing proteins are associated with syndromes conferring neurologic features and increased risk for malignancy. The best example for these conditions is ataxia-telangiectasia (AT). A more rare and recent disease is an ataxia-pancytopenia syndrome (ATXPC) associated with heterozygous gain-of-function variants in the tumor suppressor gene SAMD9L (MIM 159550). Here, we describe a patient with a complex cerebellar syndrome associated with a novel SAMD9L pathogenic variant.publishedVersio
The epidemiology of acne vulgaris in a multiethnic adolescent population from Rotterdam, the Netherlands:A cross-sectional study
Background: Although acne is a prevalent multifactorial inflammatory skin condition, few studies were performed in multiethnic populations. Objectives: To study the prevalence and determinants of acne in a multiethnic study at the start of puberty. Methods: This cross-sectional study is embedded in Generation R, a population-based prospective study from Rotterdam, the Netherlands. Three-dimensional facial photos at the center visit in 2016-2019 (of ∼13-year-olds) were used to grade acne severity using the Global Evaluation of the Acne Severity (GEA). Analyses were stratified by biological sex and explored through chi-square tests and multivariable ordinal logistic regression. Results: A total of 4561 children (51% girls) with a median age of 13.5 (IQR 13.3-13.6) were included. The visible acne prevalence (GEA 2-5) for girls vs boys was 62% vs 45% and moderate-to-severe acne (GEA 3-5) 14% vs 9%. Higher puberty stages (adjusted odds ratios: 1.38 [1.20-1.59] and 2.16 [1.86-2.51] for girls and boys, respectively) and darker skin colors V and VI (adjusted odds ratios: 1.90 [1.17-3.08] and 2.43 [1.67-3.56]) were associated with more severe acne in both sexes, and being overweight in boys (adjusted odds ratio: 1.58 [1.15-2.17]). Limitations: Cross-sectional design. Conclusions: Acne prevalence was high at the age of 13 years and was associated with advanced puberty, darker skin color, and weight status.</p
The epidemiology of acne vulgaris in a multiethnic adolescent population from Rotterdam, the Netherlands:A cross-sectional study
Background: Although acne is a prevalent multifactorial inflammatory skin condition, few studies were performed in multiethnic populations. Objectives: To study the prevalence and determinants of acne in a multiethnic study at the start of puberty. Methods: This cross-sectional study is embedded in Generation R, a population-based prospective study from Rotterdam, the Netherlands. Three-dimensional facial photos at the center visit in 2016-2019 (of ∼13-year-olds) were used to grade acne severity using the Global Evaluation of the Acne Severity (GEA). Analyses were stratified by biological sex and explored through chi-square tests and multivariable ordinal logistic regression. Results: A total of 4561 children (51% girls) with a median age of 13.5 (IQR 13.3-13.6) were included. The visible acne prevalence (GEA 2-5) for girls vs boys was 62% vs 45% and moderate-to-severe acne (GEA 3-5) 14% vs 9%. Higher puberty stages (adjusted odds ratios: 1.38 [1.20-1.59] and 2.16 [1.86-2.51] for girls and boys, respectively) and darker skin colors V and VI (adjusted odds ratios: 1.90 [1.17-3.08] and 2.43 [1.67-3.56]) were associated with more severe acne in both sexes, and being overweight in boys (adjusted odds ratio: 1.58 [1.15-2.17]). Limitations: Cross-sectional design. Conclusions: Acne prevalence was high at the age of 13 years and was associated with advanced puberty, darker skin color, and weight status.</p
Neuropeptide Y autoantibodies in patients with long-term type 1 and type 2 diabetes and neuropathy
Gender differences in nerve regeneration after sciatic nerve injury and repair in healthy and in type 2 diabetic Goto-Kakizaki rats
Peripheral nerve function : metabolic features, clinical assessment, and heat shock protein 27
Peripheral neuropathy is a common complication among patients with diabetes mellitus, but whether peripheral neuropathy is present in individuals with impaired glucose tolerance (IGT) is debatable. In order to identify and diagnose peripheral neuropathy correctly, it is important to evaluate diagnostic tools that can be implemented in routine health care to assess both large and small nerve fibre function. There is currently limited knowledge about neuroprotective factors that could be useful for measuring peripheral nerve function in individuals at risk of developing neuropathy such as those with diabetes mellitus. Thus, studies are needed to investigate potential neuroprotective factors in relation to peripheral nerve function in humans. Objectives: The overall goal of this thesis was to study the metabolic features and clinical assessment of peripheral nerve function and the potential relationship between the neuroprotective factor heat shock protein 27 (HSP27) and peripheral nerve function. Methods: Thirty-nine participants with normal glucose tolerance (NGT) and 29 participants with IGT were recruited from the population-based Västerbotten Intervention Programme in 2003–2004. Patients with type 2 diabetes mellitus (T2DM, n = 51) were recruited from primary health care centres. NGT and IGT individuals underwent two separate oral glucose tolerance tests to verify their glucose status. The peripheral nerve function in the lower limb was assessed by nerve conduction studies, neuropathy disability scoring, quantitative sensory tests, and skin biopsies with subsequent quantification of intraepidermal nerve fibre density (IENFD). The concentrations of HSP27 in serum were determined in the NGT, IGT, and T2DM individuals. Patients with type 1 diabetes mellitus (T1DM) were recruited from the Diabetes Clinic, Skåne University Hospital in Malmö, Sweden (n = 27) in 1992 and were followed-up in 2005. Baseline and follow-up concentrations of HSP27 were determined in T1DM patients as well as in healthy non-diabetic controls (n = 397). The T1DM patients underwent nerve conduction studies and thermal and vibration perception threshold tests at baseline and at follow-up. Delta changes in HSP27 concentrations and small and large nerve fibre function were calculated. Results: There was no difference between IGT and NGT in sural nerve conduction, intraepidermal nerve fibre density, or thermal thresholds. The biothesiometer had a sensitivity of 82% and a specificity of 72% in identifying peripheral neuropathy with a cut-off value of ≥24.5 V at the medial malleolus. Adding the quantification of IENFD to the combination of the tuning fork and biothesiometer increased the diagnostic sensitivity from 81% to 95%, the negative predictive value from 87% to 94%, and the positive likelihood ratio from 1.8 to 1.9 when identifying small nerve fibre dysfunction. T2DM patients had lower HSP27 concentrations (mean HSP27 = 412 pg/mL, 95% CI 284–598 pg/mL) than NGT (mean HSP27 = 722 pg/mL, 95% CI 564–922 pg/mL) and IGT (mean HSP27 = 1010 pg/mL, 95% CI 638–1300 pg/mL) individuals (p <0.05 for both comparisons). T1DM patients had lower HSP27 concentrations at baseline (mean HSP27 = 547 pg/mL, 95% CI 421–711 pg/mL) and at follow-up (mean HSP27 = 538 pg/mL, 95% CI 417–693 pg/mL) compared to healthy controls (mean HSP27 = 785 pg/mL, 95% CI 732–842 pg/mL), p <0.05 for both comparisons). High concentrations of HSP27 were associated with better large nerve fibre function (Odds ratio = 2.51, 95% CI 1.25–5.05, p <0.05). Deteriorating large nerve fibre function correlated with decreasing HSP27 concentrations over time in T1DM patients (r = 0.50, p = 0.01). Conclusions: Measures of large and small nerve fibre function in IGT individuals do not differ significantly from NGT individuals. The existence of peripheral neuropathy as a consequence of IGT is not likely, and extensive control of neuropathy in IGT individuals is not advocated by this thesis. The biothesiometer is a useful clinical tool to identify peripheral neuropathy in routine health care. Quantification of IENFD using skin biopsies in combination with methods measuring vibrotactile sense, such as the biothesiometer and the tuning fork, increase the diagnostic usefulness of identifying small nerve fibre dysfunction. High HSP27 concentrations are associated with better peripheral large nerve fibre function. Patients with diabetes mellitus have lower HSP27 concentrations than healthy non-diabetic controls, and deterioration of large nerve fibre function correlates with a decrease in HSP27 concentrations over time in T1DM. This could be indicative of insufficient neuroprotection in patients with diabetes mellitus
Identifying and Ranking of Critical Success Factors for Biotech Start-ups- An Empirical Study of Biotechnology Firms in Sweden
Nowadays, high-technology-new-ventures have a significant effect on economic growth of developed countries and are considered to have a high rate of return on investment (ROI). For instance, in Sweden, policy makers, venture capitalists (VCs) and academia have paid a special attention to biotechnology and information technology (IT). These high-tech industries are considered to increase the national competitiveness and create opportunities for employment. Despite the fact that many empirical studies investigated the business aspects of these industries in Sweden, still a few number of firm-level studies focused specifically on biotech industry to investigate the critical success factors for biotech firms in Sweden. In fact, this study was carried out in order to better understand the economic, dynamic and managerial characteristics of an industry which is recognized as being highly risky and uncertain. The study departed from understanding the definitions regarding to what is meant by biotechnology industry and exploring the current state of this industry both globally and nationwide in Sweden. On the next step, a thorough analysis of literature carried out to figure out dynamics of this industry. Based on in-depth literature review, we identified five main factors which are critical for success of biotech firms including a number of criteria under each factor. To achieve the objectives of the study, a questionnaire survey was designed and sent to a number of active biotech firms. We asked top managers in these firms to participate in a web-based survey and express their attitudes towards the significance of each criterion based on a five-point Likert scale. Later, by means of mathematical model and statistical analysis tool, we prioritized and ranked each factor and belonging criteria. The results of this study revealed five main categories for critical success factors consisting of competencies that are distinct and different with the following priority: 1) Managerial and Human Capital; 2) Knowledge Assets; 3) Funding and Financial; 4) Alliances and Networking; and 5) Location and Market factor. Under each of these categories a number of criteria have been perceived and prioritized based on the significance for success. Besides, a comparative study was conducted between start-ups and established firms in our study, to investigate the differences in perceived significance of each factor for these two firm types
Evaluation of clinical tools and their diagnostic use in distal symmetric polyneuropathy
Aims: To compare the diagnostic usefulness of tuning fork, monofilament, biothesiometer and skin biopsies in peripheral neuropathy in individuals with varying glucose metabolism. Methods: Normoglycaemic, impaired glucose tolerance (IGT) and type 2 diabetes (T2DM) individuals were recruited. Nerve conduction studies (NCS) and thermal threshold tests were performed. Vibrotactile sense was tested with a biothesiometer and a 128-Hz tuning fork. Touch/pressure perception was examined with a 10-g monofilament. Skin biopsies were performed and intraepidermal nerve fibres were quantified. Distal symmetric polyneuropathy (DSPN) was defined as neuropathy disability score >= 2 and abnormal NCS. Thermal threshold tests were used to define small nerve fibre neuropathy (sDSPN) in cases where NCS (large nerve fibres) were normal. Results: The prevalence of DSPN and sDSPN in the whole group (n = 119) was 18% and 23%, respectively. For the biothesiometer, a cut-off of >= 24.5V had a sensitivity of 82% and specificity of 70% (AUC = 0.81, 95% CI 0.71-0.91) when evaluating DSPN. An intraepidermal nerve fibre density cut-off of <= 3.39 fibres/mm showed a sensitivity of 74% and specificity of 70% in the detection of sDSPN, whereas the sensitivity of the tuning fork and the biothesiometer were relatively low, 46% and 67%, respectively. When combining skin biopsies with the tuning fork, 10 more sDSPN cases were identified. Adding skin biopsy to the combination of the tuning fork and biothesiometer increased the sensitivity of finding sDSPN cases, but not DSPN, from 81% to 93%. Conclusion: Using a biothesiometer in clinical routine might be a sensitive method to detect large nerve fibre dysfunction in the lower extremity, whereas skin biopsies in combination with methods measuring vibrotactile sense could increase the diagnostic sensitivity of detecting peripheral neuropathy at an early stage. (C) 2013 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved