Venlafaxine alters microvascular perfusion, [I]-beta-CIT binding and BDI scores in flushing postmenopausal women

Background

Although 70% of postmenopausal women suffer from hot flashes the pathophysiology is poorly understood. The serotonin and noradrenaline reuptake inhibitor (SNRI) venlafaxine provides relief of flushing although the mechanism is unknown and could involve a central effect and/or a peripheral effect. Using single photon emission computed tomography (SPECT) we studied the central serotonin transporter (SERT) in vivo using [¹²³I]-beta-carbomethoxy-3-β-(4-iodophenyl)tropane (beta-CIT) and, as previous studies have shown that reactivity of the skin blood vessels is enhanced in those who flush, we examined cutaneous microvascular perfusion.

Methods

Cutaneous microvascular perfusion was assessed in 31 postmenopausal women, with flushing, using laser Doppler imaging with iontophoresis (LDI + ION), before and after 8 weeks of treatment with venlafaxine. A sub-group of 14 of these women also had SPECT imaging at both time points to evaluate the availability of SERT in the brain. Flush frequency and score was recorded, and Beck Depression Inventory (BDI) II scores were assessed before and after treatment.

Results

Following treatment with venlafaxine, there was a significant reduction in the [¹²³I]-beta-CIT binding ratio, BDI scores, flushing and endothelial dependent perfusion response. [¹²³I]-Beta-CIT reduction was associated with BDI reduction (r² = 0.54; F = 8.8; p = 0.004), but not flushing reduction or perfusion reduction.

Conclusions

Venlafaxine resulted in a decrease in BDI II scores with an associated reduction in [¹²³I]-beta-CIT binding in a group of non-depressed women. It also improved flush frequency and severity which may be as a result of decreases seen in enhanced cutaneous microvascular perfusion.     

Gender Differences in the Relationships between Perceived Stress,Eating Behaviors,Sleep, Dietary Risk,and Body Mass Index

Background: Obesity is a growing epidemic among university students, and the high levels of stress reported by this population could contribute to this issue. Singular relationships between perceived stress; engagement in restrained, uncontrolled, and emotional eating; sleep; dietary risk; and body mass index (BMI) have been reported in the current body of literature; however, these constructs interact with each other, and the complex relationships among them are infrequently examined. Therefore, the aim of the present study was to explore the complex relationships between these constructs using mediation and moderation analyses stratified by gender. Methods: A cross-sectional study, enrolling university students from the United States (U.S.), the Netherlands, South Korea, Malaysia, Ireland, Ghana, and China, was conducted between October 2020 and January 2021 during the COVID-19 pandemic. Perceived stress; maladaptive eating behaviors including restrained, uncontrolled, and emotional eating; sleep duration and quality; dietary risk; and BMI were assessed using validated questionnaires, which were distributed through an online platform. Results: A total of 1392 students completed the online survey (379 male, 973 female, and 40 who self-identified as “other”). Uncontrolled and emotional eating mediated the relationship between perceived stress and dietary risk for both males and females; higher sleep quality weakened this relationship among female students but not males. Emotional eating mediated the relationship between perceived stress and BMI for both males and females, but higher sleep quality weakened this relationship only among females. Conclusions: Our findings suggest that students in higher education are likely to benefit from interventions to reduce uncontrolled and emotional eating. Programs that improve sleep quality, especially during highly stressful periods, may be helpful.     

Designing a novel visible-light-driven heterostructure Ni–ZnO/S-g-C3N4 photocatalyst for coloured pollutant degradation

In this study, photocorrosion of ZnO is inhibited by doping Ni in the ZnO nanostructure and electron–hole recombination was solved by forming a heterostructure with S-g-C₃N₄. Ni is doped into ZnO NPs from 0 to 10% (w/w). Among the Ni-decorated ZnO NPs, 4% Ni-doped ZnO NPs (4NZO) showed the best performance. So, 4% Ni–ZnO was used to form heterostructure NCs with S-g-C₃N₄. NZO NPs were formed by the wet co-precipitation route by varying the weight percentage of Ni (0–10% w/w). Methylene blue (MB) was used as a model dye for photocatalytic studies. For the preparation of the 4NZO-x-SCN nanocomposite, 4NZO NPs were formed in situ in the presence of various concentrations of S-g-C₃N₄ (10–50% (w/w)) by using the coprecipitation route. The electron spin resonance (ESR) and radical scavenger studies showed that O₂⁻ and OH free radicals were the main reactive species that were responsible for MB photodegradation.

Ni-doped ZnO/S-g-C₃N₄ nanocomposites were formed as a novel heterostructure photocatalyst.