Linking the FTO obesity rs1421085 variant circuitry to cellular, metabolic, and organismal phenotypes in vivo

Variants in FTO have the strongest association with obesity; however, it is still unclear how those noncoding variants mechanistically affect whole-body physiology. We engineered a deletion of the rs1421085 conserved cis-regulatory module (CRM) in mice and confirmed in vivo that the CRM modulates Irx3 and Irx5 gene expression and mitochondrial function in adipocytes. The CRM affects molecular and cellular phenotypes in an adipose depot-dependent manner and affects organismal phenotypes that are relevant for obesity, including decreased high-fat diet-induced weight gain, decreased whole-body fat mass, and decreased skin fat thickness. Last, we connected the CRM to a genetically determined effect on steroid patterns in males that was dependent on nutritional challenge and conserved across mice and humans. Together, our data establish cross-species conservation of the rs1421085 regulatory circuitry at the molecular, cellular, metabolic, and organismal level, revealing previously unknown contextual dependence of the variant's action.

Acute alcohol does not impair attentional inhibition as measured with Stroop interference scores but impairs Stroop performance

RATIONALE

Inhibition is a core executive function and refers to the ability to deliberately suppress attention, behavior, thoughts, and/or emotions and instead act in a specific manner. While acute alcohol exposure has been shown to impair response inhibition in the stop-signal and Go/NoGo tasks, reported alcohol effects on attentional inhibition in the Stroop task are inconsistent. Notably, studies have operationalized attentional inhibition variably and there has been intra- and inter-individual variability in alcohol exposure.

OBJECTIVE

This study aimed to examine the acute effects of alcohol on attentional inhibition, considering previous limitations.

METHODS

In a single-blind, cross-over design, 40 non-dependent participants with a medium-to-high risk drinking behavior performed a Counting Stroop task (CST) under a baseline and an arterial blood alcohol concentration (aBAC) clamp at 80 mg%. Attentional inhibition was assessed as the alteration of reaction times (RT), error rates (ER), and inverse efficiency scores (IES) between incongruent and congruent trials (interference score). Stroop performance was also assessed regardless of trial-type.

RESULTS

Compared to saline, acute alcohol exposure via an aBAC clamp did not affect CST interference scores but increased RTs and IES in both incongruent and congruent trials.

CONCLUSIONS

Attentional inhibition (Stroop interference score) was not impaired by clamped moderate alcohol exposure. Acute alcohol impaired Stroop performance evidenced by a general increase in response times. Our findings suggest that response and attentional inhibition do not share the same neurocognitive mechanisms and are affected differently by alcohol. Results could also be explained by automated behaviors known to be relatively unaffected by acute alcohol.

Extensive monitoring of the natural menstrual cycle using the serum biomarkers estradiol, luteinizing hormone and progesterone

Expected values for estradiol (E2), luteinizing hormone (LH), and progesterone determined in serum allow accurate assessment of menstrual cycle phase. Automated immunoassays demonstrate variable degrees of bias, emphasizing the need to establish method-specific reference values. We therefore established method-specific reference intervals for the Elecsys® LH assay and new generation Elecsys Estradiol III and Progesterone III assays (cobas e 801 analyzer) in 85 apparently healthy women aged 22–37 (US)/18–37 (EU) years over one natural menstrual cycle. Cycle length and day of ovulation were standardized; phases were defined by LH surge and/or progesterone/E2 levels. Median (5th–95th percentile) concentrations (follicular/ovulation/luteal) were E2: 198 ​pmol/L (114–332), 757 ​pmol/L (222–1959) and 412 ​pmol/L (222–854); LH: 7.14 IU/L (4.78–13.2), 22.6 IU/L (8.11–72.7) and 6.24 IU/L (2.73–13.1); progesterone: 0.212 ​nmol/L (0.159–0.616), 1.81 ​nmol/L (0.175–13.2) and 28.8 ​nmol/L (13.1–46.3). Sub-phase (early/intermediate/late) reference values were also determined for follicular and luteal phases. This multicenter study established reliable, method-specific E2, LH and progesterone reference values that could assist clinical decision-making in women with fertility disorders and monitoring of natural cycles in assisted reproductive treatment.

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E2, LH and progesterone are biomarkers for assessing natural menstrual cycle phase.

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These biomarkers support diagnosis, monitoring and treatment of fertility disorders.

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E2, LH and progesterone profiles were derived using new generation Elecsys® assays.

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Expected serum values are presented for each menstrual cycle phase and sub-phase.

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Data will inform clinical decision-making for women with fertility disorders.

Interconnected electrocatalytic Pt-metal networks by plasma treatment of nanoparticle-peptide fibril assemblies

Noble metal catalysts possess outstanding catalytic behaviors, photocatalysis, electrocatalysis and many other applications, when interconnected via peptide fibrils.

Associations Between C-Reactive Protein, Insulin Sensitivity, and Resting Metabolic Rate in Adults: A Mediator Analysis

Objective: Long-term positive energy balance promotes the development of obesity, a main risk factor for type 2 diabetes mellitus (T2DM). While an association between increased resting metabolic rate (RMR) and insulin sensitivity (IS) was shown previously, the underlying mechanisms remain unclear. Aim of the mediator analysis was to investigate the role of inflammation within the association between RMR and IS. Methods: Anthropometric, clinical, and lifestyle data were collected according to standard operating procedures. RMR was measured using indirect calorimetry. Homeostasis model assessment for insulin resistance (HOMA-IR) was used as an IS parameter and C-reactive protein (CRP) was measured to represent the inflammatory status. Statistical analyses were performed using SPSS. Results: The analysis included 782 adults (517 females) with a mean age of 32.4 ± 12.0 years and a mean body mass index (BMI) of 24.6 ± 5.2 kg/m². Regression analysis indicated a significant evidence for associations between RMR and HOMA-IR (ß = 39.3 ± 7.3 kcal/d; p ≤ 0.001) and CRP and HOMA-IR (ß = 0.5 ± 0.1; p ≤ 0.001) after adjustment for fat-free mass, sex, age, and study site. Results of the mediator analysis did not support the hypothesis that CRP is a mediator for the association between RMR and HOMA-IR. These results did not change after participant stratification according to sex or BMI. Conclusion: A significant evidence for an association between RMR and IS was shown in a large cohort. However, the inflammatory status, determined via CRP levels, was not a mediator within this association.

Determinants of urolithiasis in patients with intestinal fat malabsorption

OBJECTIVE

To investigate the determinants of urinary stone formation in patients with fat malabsorption, because, although the prevalence of urolithiasis is greater in patients with intestinal diseases, the pathogenetic mechanisms and risk factors associated with urolithiasis in this population remain partially unsolved.

MATERIALS AND METHODS

The present study retrospectively analyzed the determinants of urolithiasis in 51 patients with fat malabsorption due to different intestinal diseases. Anthropometric, clinical, blood, 24-hour urinary parameters, and dietary intake were assessed.

RESULTS

The resection rate (ie, pancreatic and/or bowel resection) differed significantly between stone formers (SF; n=10) and nonstone formers (NSF; n=41; 70% vs 29%; P=.027). Urinary citrate was lower (1.606±1.824 vs 3.156±1.968 mmol/24 h; P=.027), while oxalate excretion (0.659±0.292 vs 0.378±0.168 mmol/24 h; P=.002) and the relative supersaturation of calcium oxalate were greater in SF than NSF (8.16±4.61 vs 3.94±2.93; P=.003). Total cholesterol and low-density lipoprotein cholesterol, but also high-density lipoprotein cholesterol, plasma β-carotene, and vitamin E concentrations, were significantly diminished, whereas serum aspartate aminotransferase activity was significantly greater in SF compared with NSF. Binary logistic regression analysis revealed resection status as a major extrarenal risk factor for stone formation (odds ratio 5.639).

CONCLUSION

Increased urinary oxalate and decreased citrate excretion, probably resulting from pancreatic and/or bowel resection with mainly preserved colon, were identified as the most crucial urinary risk factors for stone formation in patients with fat malabsorption. The findings suggest that hyperoxaluria predominantly results from increased colonic permeability for oxalate due to disturbed bile acid metabolism. The impaired status of fat-soluble antioxidants β-carotene and vitamin E indicates severe malabsorptive states associated with an enhanced stone-forming propensity.

Determinants of urolithiasis in patients with intestinal fat malabsorption

OBJECTIVE

To investigate the determinants of urinary stone formation in patients with fat malabsorption, because, although the prevalence of urolithiasis is greater in patients with intestinal diseases, the pathogenetic mechanisms and risk factors associated with urolithiasis in this population remain partially unsolved.

MATERIALS AND METHODS

The present study retrospectively analyzed the determinants of urolithiasis in 51 patients with fat malabsorption due to different intestinal diseases. Anthropometric, clinical, blood, 24-hour urinary parameters, and dietary intake were assessed.

RESULTS

The resection rate (ie, pancreatic and/or bowel resection) differed significantly between stone formers (SF; n=10) and nonstone formers (NSF; n=41; 70% vs 29%; P=.027). Urinary citrate was lower (1.606±1.824 vs 3.156±1.968 mmol/24 h; P=.027), while oxalate excretion (0.659±0.292 vs 0.378±0.168 mmol/24 h; P=.002) and the relative supersaturation of calcium oxalate were greater in SF than NSF (8.16±4.61 vs 3.94±2.93; P=.003). Total cholesterol and low-density lipoprotein cholesterol, but also high-density lipoprotein cholesterol, plasma β-carotene, and vitamin E concentrations, were significantly diminished, whereas serum aspartate aminotransferase activity was significantly greater in SF compared with NSF. Binary logistic regression analysis revealed resection status as a major extrarenal risk factor for stone formation (odds ratio 5.639).

CONCLUSION

Increased urinary oxalate and decreased citrate excretion, probably resulting from pancreatic and/or bowel resection with mainly preserved colon, were identified as the most crucial urinary risk factors for stone formation in patients with fat malabsorption. The findings suggest that hyperoxaluria predominantly results from increased colonic permeability for oxalate due to disturbed bile acid metabolism. The impaired status of fat-soluble antioxidants β-carotene and vitamin E indicates severe malabsorptive states associated with an enhanced stone-forming propensity.

Spatial integration in polarization-sensitive interneurones of crickets: a survey of evidence, mechanisms and benefits

Many insects exploit the polarization pattern of the sky for compass orientation in navigation or cruising-course control. Polarization-sensitive neurones (POL1-neurones) in the polarization vision pathway of the cricket visual system have wide visual fields of approximately 60° diameter, i.e. these neurones integrate information over a large area of the sky. This results from two different mechanisms. (i) Optical integration; polarization vision is mediated by a group of specialized ommatidia at the dorsal rim of the eye. These ommatidia lack screening pigment, contain a wide rhabdom and have poor lens optics. As a result, the angular sensitivity of the polarization-sensitive photoreceptors is very wide (median approximately 20°). (ii) Neural integration; each POL1-neurone receives input from a large number of dorsal rim photoreceptors with diverging optical axes. Spatial integration in POL1-neurones acts as a spatial low-pass filter. It improves the quality of the celestial polarization signal by filtering out cloud-induced local disturbances in the polarization pattern and increases sensitivity.

Succinylcholine metabolite succinic acid alters steady state activation in muscle sodium channels

BACKGROUND

Animal experiments revealed that succinylcholine produced masseter muscle rigidity and activated myotonic discharges despite neuromuscular blockade with a nondepolarizing blocker. These results suggest that either succinylcholine or its metabolites might interfere directly with voltage-operated ion channels of the sarcolemma. The aim of this study was to examine effects of one product of succinylcholine hydrolysis, succinic acid, on voltage-gated muscle sodium (Na+) channels.

METHODS

Alpha subunits of human muscle sodium channels were heterologously expressed in HEK293 cells. Activation of Na+ currents was examined applying standard whole-cell voltage-clamp protocols in the absence (control and washout) and presence of succinic acid in different concentrations (0.05-10 mm).

RESULTS

Succinic acid shifted the midpoints of steady state activation plots in the direction of more negative test potentials, indicating that channels open during smaller depolarizations in the presence of the drug. The maximum amount of the negative shift in 10 mm succinic acid was -6.3 +/- 1.7 mV; the EC50 for this effect was 0.39 mm. In addition, succinic acid (10 mm) significantly enhanced maximum currents after depolarizations with respect to a series of control experiments.

CONCLUSION

Succinic acid facilitates voltage-dependent activation in muscle sodium channels in vitro. This might lead to muscle hyperexcitability in vivo.

[Psychotherapy in general practice of physicians and psychologists]

This study tries to reveal the epidemiology of outpatient psychotherapy in practices in a defined northern area of Germany (Schleswig-Holstein, 2.66 Mill. inhabitants) by a postal questioning of all medical (n = 242) and psychological (n = 45) psychotherapists registered. Psychotherapy was defined as enclosing at least 10 meetings. 54.7% of the questionnaires were returned to us. An analysis on this database showed that 8310 adult patients were psychotherapeutically treated within one year (0.3% of the population). On the base of different epidemiological studies the treatment prevalence widely differed from 3.9 to 31.9%. The majority of diagnoses were reactive disorders or neuroses (52.8%) and psychosomatic disorders (24.3%). Patients out of middle and upper social classes, with higher educational levels, and from urban areas (> 100 000 inhabitants) were more likely to be treated than others. This trend was significantly more apparent in psychologists than in physicians.

A new method for the classification of subvigil stages, using the Fourier transform, and its application to sleep apnea

An online classification for two-second segments of the EEG is developed. Based on the calculation of a norm and three characteristic frequencies the automatic classification shows satisfactory agreement with visual classification. The influence of the Fourier phase spectra is discussed. Trajectories in the parameter space are introduced. The automatic classification was applied to patients with a pronounced sleep-wake disorder and proved to be valuable in the diagnosis of a disturbed sleep structure.