The effect of overt and subclinical hypothyroidism on the development of non-dipper blood pressure

Introduction: ′Non-dippers′ are individuals without the anticipated nocturnal decrease in blood pressure. An increased incidence of target organ damage and a worse outcome in terms of cardiovascular events have been reported in this group of people. The pathogenesis of non-dipper hypertension is not clear at present. We aimed to investigate the effects of overt and subclinical hypothyroidism on the development of a non-dipper blood pressure pattern via 24-hour ambulatory blood pressure monitoring. Material and methods: 109 normotensive patients with overt and subclinical hypothyroidism were evaluated, and 95 of these patients without reverse dipping and masked hypertension were included in the study. The control group consisted of 75 gender- and age-matched, normotensive, euthyroid healthy individuals. Results: Median serum TSH levels were 7.61 and 1.59 mUmL in patient and control groups, respectively. The number of non-dippers according to systolic, diastolic and mean blood pressure was significantly higher in the patients with hypothyroidism compared to the control group. In linear regression analysis, TSH had a negative effect on the night/day ratio of the systolic, diastolic and mean blood pressures. Conclusion: Despite the fact that the effect of hypothyroidism on non-dipper blood pressure pattern is not known, the present study has revealed that elevated TSH levels are likely to increase the risk of non-dipping in normotensive patients with either overt or subclinical hypothyroidism. (Pol J Endocrinol 2012; 63 (2): 97–103)Wstęp: U osób określanych jako non-dippers nie występuje fizjologiczne obniżenie ciśnienia tętniczego w godzinach nocnych. Jak wynika z doniesień, w tej grupie chorych częściej dochodzi do zmian narządowych i zdarzeń sercowo-naczyniowych. Patogenezy nadciśnienia tętniczego typu non-dipper dotychczas nie wyjaśniono. Celem autorów było zbadanie wpływu jawnej i subklinicznej niedoczynności tarczycy na rozwój profilu dobowej zmienności ciśnienia tętniczego typu non-dipper metodą całodobowego automatycznego pomiaru ciśnienia tętniczego. Materiał i metody: Spośród 109 chorych z prawidłowym ciśnieniem i z jawną lub subkliniczną niedoczynnością tarczycy do analizy włączono 95 osób, u których nie występował nocny wzrost ciśnienia tętniczego (reverse dipping) ani utajone nadciśnienie tętnicze. Grupa kontrolna składała się z 75 zdrowych osób z prawidłowym ciśnieniem tętniczym i prawidłową czynnością tarczycy odpowiednio dobranych pod względem płci i wieku. Wyniki: Mediany stężeń TSH w surowicy w grupach badanej i kontrolnej wynosiły odpowiednio 7,61 i 1,59 mUml. Liczba osób, u których nie występował nocny spadek wartości skurczowego, rozkurczowego i średniego ciśnienia tętniczego, był istotnie wyższy w grupie chorych z niedoczynnością tarczycy niż w grupie kontrolnej. W analizie regresji liniowej wykazano istnienie odwrotnej zależności między stężeniem TSH a stosunkiem między nocnymi i dziennymi wartościami ciśnienia skurczowego, rozkurczowego i średniego ciśnienia tętniczego. Wnioski: Mimo że nie wiadomo, jaki jest mechanizm oddziaływania niedoczynności tarczycy na rozwój dobowego profilu ciśnienia tętniczego typu non-dipper, w niniejszym badaniu wykazano, że podwyższone stężenie TSH może zwiększać ryzyko wystąpienia takiego profilu ciśnienia tętniczego u osób z prawidłowym ciśnieniem tętniczym i jawną lub subkliniczną niedoczynnością tarczycy. (Endokrynol Pol 2012; 63 (2): 97–103

The community ecology perspective of omics data

The measurement of uncharacterized pools of biological molecules through techniques such as metabarcoding, metagenomics, metatranscriptomics, metabolomics, and metaproteomics produces large, multivariate datasets. Analyses of these datasets have successfully been borrowed from community ecology to characterize the molecular diversity of samples (ɑ-diversity) and to assess how these profiles change in response to experimental treatments or across gradients (β-diversity). However, sample preparation and data collection methods generate biases and noise which confound molecular diversity estimates and require special attention. Here, we examine how technical biases and noise that are introduced into multivariate molecular data affect the estimation of the components of diversity (i.e., total number of different molecular species, or entities; total number of molecules; and the abundance distribution of molecular entities). We then explore under which conditions these biases affect the measurement of ɑ- and β-diversity and highlight how novel methods commonly used in community ecology can be adopted to improve the interpretation and integration of multivariate molecular data. Video Abstract

Prevalence of Helicobacter pylori in symptomatic patients and detection of clarithromycin resistance using melting curve analysis

AbstractBackground:Clarithromycin is often a component of combination therapies for Helicobacter pylori eradication; however, increases in resistance rates have decreased the success of the treatment.Objective:This study was designed to determine the prevalence of H pylori infection in symptomatic patients and to detect clarithromycin resistance rates using melting curve analysis.Methods:Patients scheduled for upper endoscopy at the Endoscopy Unit of the Department of Gastroenterology, Duzce University, Medical Faculty Hospital, Konuralp/Duzce, Turkey, were assessed for enrollment in the study. Two pairs of gastric biopsy specimens (antrum and corpus) were obtained from each study patient. Histopathologic examination, rapid urease test, culture, and polymerase chain reaction (PCR) of the specimens were used to identify H pylori infection. Clarithromycin resistance was detected using melting curve analysis.Results:Seventy-five patients (41 women, 34 men; mean [SD]age, 42.6 [14.5] years [range, 17–70 years]) were included in the study. Using histopathology and rapid urease test, H pylori was detected in 40 (53.3%) of the 75 specimens. H pylori was detected using PCR in 40 (53.3%) specimens and by culture in 10 (13.3%) specimens. The specificity and sensitivity of PCR and culture were interpreted by comparing them with the results of histopathologic examination and urease tests. The specificity and sensitivity of PCR were 68.6% and 72.5%, respectively, and the specificity and sensitivity of culture were 97.1% and 22.5%, respectively. Of the 40 isolates, 21 (52.5%) were susceptible to clarithromycin, 12 (30.0%) were resistant, and a mixed susceptibility pattern was detected in 7 (17.5%) specimens. H pylori isolates from 19 (79.2%) of the 24 patients who had formerly used clarithromycin showed clarithromycin resistance.Conclusions:The prevalence of H pylori infection was 53.3% for the symptomatic patients in this study, and 47.5% of the isolates showed clarithromycin resistance using melting curve analysis. The PCR-based system used in this study was accurate for the detection of H pylori infection as well as clarithromycin susceptibility testing directly in biopsy specimens

A MAC Mode for Lightweight Block Ciphers

status: accepte

Relationships of temperature and biodiversity with stability of natural aquatic food webs

Temperature and biodiversity changes occur in concert, but their joint effects on ecological stability of natural food webs are unknown. Here, we assess these relationships in 19 planktonic food webs. We estimate stability as structural stability (using the volume contraction rate) and temporal stability (using the temporal variation of species abundances). Warmer temperatures were associated with lower structural and temporal stability, while biodiversity had no consistent effects on either stability property. While species richness was associated with lower structural stability and higher temporal stability, Simpson diversity was associated with higher temporal stability. The responses of structural stability were linked to disproportionate contributions from two trophic groups (predators and consumers), while the responses of temporal stability were linked both to synchrony of all species within the food web and distinctive contributions from three trophic groups (predators, consumers, and producers). Our results suggest that, in natural ecosystems, warmer temperatures can erode ecosystem stability, while biodiversity changes may not have consistent effects

The qualitative transparency deliberations: insights and implications

In recent years, a variety of efforts have been made in political science to enable, encourage, or require scholars to be more open and explicit about the bases of their empirical claims and, in turn, make those claims more readily evaluable by others. While qualitative scholars have long taken an interest in making their research open, reflexive, and systematic, the recent push for overarching transparency norms and requirements has provoked serious concern within qualitative research communities and raised fundamental questions about the meaning, value, costs, and intellectual relevance of transparency for qualitative inquiry. In this Perspectives Reflection, we crystallize the central findings of a three-year deliberative process—the Qualitative Transparency Deliberations (QTD)—involving hundreds of political scientists in a broad discussion of these issues. Following an overview of the process and the key insights that emerged, we present summaries of the QTD Working Groups’ final reports. Drawing on a series of public, online conversations that unfolded at www.qualtd.net, the reports unpack transparency’s promise, practicalities, risks, and limitations in relation to different qualitative methodologies, forms of evidence, and research contexts. Taken as a whole, these reports—the full versions of which can be found in the Supplementary Materials—offer practical guidance to scholars designing and implementing qualitative research, and to editors, reviewers, and funders seeking to develop criteria of evaluation that are appropriate—as understood by relevant research communities—to the forms of inquiry being assessed. We dedicate this Reflection to the memory of our coauthor and QTD working group leader Kendra Koivu

Childhood trauma, life-time self-harm, and suicidal behaviour and ideation are associated with polygenic scores for autism

Abstract: Autistic individuals experience significantly elevated rates of childhood trauma, self-harm and suicidal behaviour and ideation (SSBI). Is this purely the result of negative environmental experiences, or does this interact with genetic predisposition? In this study we investigated if a genetic predisposition for autism is associated with childhood trauma using polygenic scores (PGS) and genetic correlations in the UK Biobank (105,222 < N < 105,638), and tested potential mediators and moderators of the association between autism, childhood trauma and SSBI. Autism PGS were significantly associated with childhood trauma (max R2 = 0.096%, P < 2 × 10−16), self-harm ideation (max R2 = 0.108%, P < 2 × 10−16), and self-harm (max R2 = 0.13%, P < 2 × 10−16). Supporting this, we identified significant genetic correlations between autism and childhood trauma (rg = 0.36 ± 0.05, P = 8.13 × 10−11), self-harm ideation (rg = 0.49 ± 0.05, P = 4.17 × 10−21) and self-harm (rg = 0.48 ± 0.05, P = 4.58 × 10−21), and an over-transmission of PGS for the two SSBI phenotypes from parents to autistic probands. Male sex negatively moderated the effect of autism PGS on childhood trauma (β = −0.023 ± 0.005, P = 6.74 × 10−5). Further, childhood trauma positively moderated the effect of autism PGS on self-harm score (β = 8.37 × 10−3 ± 2.76 × 10−3, P = 2.42 × 10−3) and self-harm ideation (β = 7.47 × 10−3 ± 2.76 × 10−3, P = 6.71 × 10−3). Finally, depressive symptoms, quality and frequency of social interactions, and educational attainment were significant mediators of the effect of autism PGS on SSBI, with the proportion of effect mediated ranging from 0.23 (95% CI: 0.09–0.32) for depression to 0.008 (95% CI: 0.004–0.01) for educational attainment. Our findings identify that a genetic predisposition for autism is associated with adverse life-time outcomes, which represent complex gene-environment interactions, and prioritizes potential mediators and moderators of this shared biology. It is important to identify sources of trauma for autistic individuals in order to reduce their occurrence and impact