A Modest Protective Effect of Thyrotropin against Bone Loss Is Associated with Plasma Triiodothyronine Levels

Background

The independent skeletal effect of thyrotropin (thyroid stimulating hormone, TSH) has been suggested in animal studies. However, clinical data on the association between bone loss and variations in TSH levels is inconsistent. This study aimed to investigate the relationship between TSH levels and bone mineral density (BMD).

Methods

We conducted a cross-sectional study with 37,431 subjects (33,052 cases with euthyroidism and 4,379 cases with subclinical thyroid dysfunction) aged over 35 years. We performed thyroid function tests and measured BMD at the lumbar spine, femur neck, and total hip.

Results

Levels of TSH and T3 were positively correlated in women (r = 0.076, P = 0.001) and uncorrelated in men. In both men and women, TSH levels correlated positively and T3 levels correlated negatively with BMD at all skeletal sites in age and body mass index adjusted analyses. BMD increased steadily with TSH levels from the subclinical hyperthyroid to subclinical hypothyroid range in subjects with T3 levels in the highest tertile (119.5–200.0 ng/dL), but was no longer significant in subjects with lower plasma T3 levels.

Conclusions

The variations in TSH levels within the euthyroid and subclinical range were positively correlated with BMD in healthy men and women. The negative effect of T3 on BMD appears to be compensated for by increased TSH in subjects with plasma T3 levels in the upper normal range.     

<Emphasis Type="Italic">Pedobacter yonginense</Emphasis> sp. nov., isolated from a mesotrophic artificial Lake in Korea

A non-motile red-pigmented bacterium, designated strain HMD1002^T, was isolated from an artificial lake located on the campus of Hankuk University of Foreign Studies, South Korea. The major fatty acids were iso-C_15:0 (29.6%), Summed Feature 3 (comprising C_16:1 ω7c and/or iso-C_15:0 2-OH; 17.5%) and iso-C_17:0 3-OH (12.5%). The major isoprenoid quinone was menaquinone-7 (MK-7). The DNA G+C content was 41.0 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain HMD1002^T formed a lineage in the genus Pedobacer and was closely related to Pedobacer terrae (96.3%) and Pedobacer suwonensis (95.8%) in sequence similarity. On the basis of the evidence presented in this study, strain HMD1002^T represents a novel species of the genus Pedobacter, for which the name Pedobacter yonginense sp.nov. is proposed. The type strain is HMD1002^T (=KCTC 22721^T = CEC^T 7544^T).     

Diversity of cold-active protease-producing bacteria from arctic terrestrial and marine environments revealed by enrichment culture

A new approach for enrichment culture was applied to obtain cold-active protease-producing bacteria for marine and terrestrial samples from Svalbard, Norway. The method was developed for the enrichment of bacteria by long-term incubation at low temperatures in semi-solid agar medium containing meat pieces as the main source of carbon and energy. ZoBell and 0.1× nutrient broth were added for marine and terrestrial microorganisms, respectively, to supply basal elements for growth. One to three types of colonies were observed from each enrichment culture, indicating that specific bacterial species were enriched during the experimental conditions. Among 89 bacterial isolates, protease activity was observed from 48 isolates in the screening media containing skim milk. Good growth was observed at 4°C and 10°C while none of the isolates could grow at 37°C. At low temperatures, enzyme activity was equal to or higher than activity at higher temperatures. Bacterial isolates were included in the genera Pseudoalteromonas (33 isolates), Arthrobacter (24 isolates), Pseudomonas (16 isolates), Psychrobacter (6 isolates), Sphingobacterium (6 isolates), Flavobacterium (2 isolates), Sporosarcina (1 isolate), and Stenotrophomonas (1 isolate). Protease activity was observed from Pseudoalteromonas (33 isolates), Pseudomonas (10 isolates), Arthrobacter (4 isolates), and Flavobacterium (1 isolate).     

A novel mutation in the SCN5A gene is associated with Brugada syndrome

Brugada syndrome (BS) is an inherited cardiac disorder associated with a high risk of sudden cardiac death and is caused by mutations in the SCN5A gene encoding the cardiac sodium channel alpha-subunit (Na(v)1.5). The aim of this study was to identify the genetic cause of familial BS and characterize the electrophysiological properties of a novel SCN5A mutation (W1191X). Four families and one patient with BS were screened for SCN5A mutations by PCR and direct sequencing. Wild-type (WT) and mutant Na(v)1.5 channels were expressed in tsA201 cells, and the sodium currents (I(Na)) were analyzed using the whole-cell patch-clamp technique. A novel mutation, W1191X, was identified in a family with BS. Expression of the WT or the mutant channel (Na(v)1.5/W1191X) co-transfected with the beta(1)-subunit in tsA201 cells resulted in a loss of function of Na(v)1.5 channels. While voltage-clamp recordings of the WT channel showed a distinct acceleration of Na(v)1.5 activation and fast inactivation kinetics, the Na(v)1.5/W1191X mutant failed to generate any currents. Co-expression of the WT channel and the mutant channel resulted in a 50% reduction in I(Na). No effect on activation and inactivation were observed with this heterozygous expression. The W1191X mutation is associated with BS and resulted in the loss of function of the cardiac sodium channel.     

Determination of bevantolol enantiomers in human plasma by coupled achiral-chiral high performance-liquid chromatography

A coupled achiral-chiral high performance liquid chromatographic method was developed and fully validated for the determination of bevantolol enantiomers, (-)-(S)-bevantolol and (+)-(R)-bevantolol, in human plasma. Plasma samples were prepared by solid phase extraction with Sep-Pak Plus C18 cartridges followed by HPLC. Bevantolol enantiomers and (+)-(R)-Propranolol as internal standard (IS) were preseparated from interfering components in plasma on a Phenomenex silica column and bevantolol enantiomers and IS were resolved and determined on a Chiralcel OJ-H chiral stationary phase. The two columns were connected by a switching valve equipped with silica precolumn. The Precolumn was used to concentrate bevantolol in the eluent from the achiral column before back flushing onto chiral phase. A detailed validation of the method was performed accordingly to FDA guidelines. For each enantiomer the assay was linear between 20 and 1600 ng/ml. The quantification limits of both bevantolol enantiomers were 20 ng/ml. The intraday variation was between 1.07 and 12.64% in relation to the measured concentration and the interday variation was 0.91 and 11.79%. The method has been applied to the determination of (-)-(S)- and (+)-(R)-bevantolol in plasma from healthy volunteers dosed with racemic bevantolol hydrochloride.     

Fibrinogen gamma-A chain precursor in CSF: a candidate biomarker for Alzheimer's disease

Background  

Cerebrospinal fluid (CSF) may be valuable for exploring protein markers for the diagnosis of Alzheimer's disease (AD). The prospect of early detection and treatment, to slow progression, holds hope for aging populations with increased average lifespan. The aim of the present study was to investigate candidate CSF biological markers in patients with mild cognitive impairment (MCI) and AD and compare them with age-matched normal control subjects.     

Home-based exercise rehabilitation in addition to specialist heart failure nurse care: design, rationale and recruitment to the Birmingham Rehabilitation Uptake Maximisation study for patients with congestive heart failure (BRUM-CHF): a randomised controlled trial

Background

We aimed to assess whether we could identify a graded association between increasing number of components of the metabolic syndrome and cardiac structural and functional abnormalities independently of predicted risk of coronary heart disease by the Framingham risk score.

Methods

We conducted a cross-sectional study on a random sample of the urban population of Porto aged 45 years or over. Six hundred and eighty-four participants were included. Data were collected by a structured clinical interview with a physician, ECG and a transthoracic M-mode and 2D echocardiogram. The metabolic syndrome was defined according to ATPIII-NCEP. The association between the number of features of the metabolic syndrome and the cardiac structural and functional abnormalities was assessed by 3 multivariate regression models: adjusting for age and gender, adjusting for the 10-year predicted risk of coronary heart disease by Framingham risk score and adjusting for age, gender and systolic blood pressure.

Results

There was a positive association between the number of features of metabolic syndrome and parameters of cardiac structure and function, with a consistent and statistically significant trend for all cardiac variables considered when adjusting for age and gender. Parameters of left ventricular geometry patterns, left atrial diameter and diastolic dysfunction maintained this trend when taking into account the 10-year predicted risk of coronary heart disease by the Framingham score as an independent variable, while left ventricular systolic dysfunction did not. The prevalence of left ventricular diastolic dysfunction, and the mean left ventricular mass, left ventricular diameter and left atrial diameter increased significantly with the number of features of the metabolic syndrome when additionally adjusting for systolic blood pressure as a continuous variable.

Conclusion

Increasing severity of metabolic syndrome was associated with increasingly compromised structure and function of the heart. This association was independent of Framingham risk score for indirect indices of diastolic dysfunction but not systolic dysfunction, and was not explained by blood pressure level.     

Optimisation of a quantitative polymerase chain reaction-based strategy for the detection and quantification of human herpesvirus 6 DNA in patients undergoing allogeneic haematopoietic stem cell transplantation

Human herpesvirus 6 (HHV-6) may cause severe complications after haematopoietic stem cell transplantation (HSCT). Monitoring this virus and providing precise, rapid and early diagnosis of related clinical diseases, constitute essential measures to improve outcomes. A prospective survey on the incidence and clinical features of HHV-6 infections after HSCT has not yet been conducted in Brazilian patients and the impact of this infection on HSCT outcome remains unclear. A rapid test based on real-time quantitative polymerase chain reaction (qPCR) has been optimised to screen and quantify clinical samples for HHV-6. The detection step was based on reaction with TaqMan^® hydrolysis probes. A set of previously described primers and probes have been tested to evaluate efficiency, sensitivity and reproducibility. The target efficiency range was 91.4% with linearity ranging from 10-10⁶ copies/reaction and a limit of detection of five copies/reaction or 250 copies/mL of plasma. The qPCR assay developed in the present study was simple, rapid and sensitive, allowing the detection of a wide range of HHV-6 loads. In conclusion, this test may be useful as a practical tool to help elucidate the clinical relevance of HHV-6 infection and reactivation in different scenarios and to determine the need for surveillance.     

Compartment‐specific aggregases direct distinct nuclear and cytoplasmic aggregate deposition

Disruption of the functional protein balance in living cells activates protective quality control systems to repair damaged proteins or sequester potentially cytotoxic misfolded proteins into aggregates. The established model based on Saccharomyces cerevisiae indicates that aggregating proteins in the cytosol of eukaryotic cells partition between cytosolic juxtanuclear (JUNQ) and peripheral deposits. Substrate ubiquitination acts as the sorting principle determining JUNQ deposition and subsequent degradation. Here, we show that JUNQ unexpectedly resides inside the nucleus, defining a new intranuclear quality control compartment, INQ, for the deposition of both nuclear and cytosolic misfolded proteins, irrespective of ubiquitination. Deposition of misfolded cytosolic proteins at INQ involves chaperone‐assisted nuclear import via nuclear pores. The compartment‐specific aggregases, Btn2 (nuclear) and Hsp42 (cytosolic), direct protein deposition to nuclear INQ and cytosolic (CytoQ) sites, respectively. Intriguingly, Btn2 is transiently induced by both protein folding stress and DNA replication stress, with DNA surveillance proteins accumulating at INQ. Our data therefore reveal a bipartite, inter‐compartmental protein quality control system linked to DNA surveillance via INQ and Btn2.