Implementation and impact of a technology-based HIV risk-reduction intervention among Thai men who have sex with men using “Vialogues”: a randomized controlled trial

ABSTRACT

We conducted a randomized control trial to evaluate the impact of a novel technology-based intervention on HIV risks and condom use behaviors among Thai men who have sex with men (MSM). Between April 2016 and August 2017, participants aged 18 years and above, and having engaged in unprotected sex in past six months were randomly assigned to control and intervention arm, and received HIV testing at baseline, month 6 and 12. Intervention arm participants engaged in 12-monthly HIV/STI prevention educational sessions delivered via Vialogues.com. Of 76 MSM enrolled, 37 were randomized to intervention and 39 to control arm. Median age was 28 (IQR 24–32) years. Thirty-three (89.2%) intervention arm participants completed all 12-monthly Vialogues sessions. At month 12, intervention arm had higher retention rate (p?=?0.029) and higher median percentage of condom use for anal intercourse (p?=?0.023) versus control arm. Over the 12-month period, intervention arm reported significant reduction in self-perceived HIV risk (p?=?0.001), popper usage (p?=?0.002), median number of sexual partners (p?=?0.003), and increased median condom use percentage (p?=?0.006). Our study highlights that “Vialogues” intervention significantly reduced number of sexual partners and condomless anal intercourse rates among Thai MSM, and has positive implications for reducing epidemic among key populations.     

Phytochemical profiling and phase II enzyme-inducing properties of Thunbergia laurifolia Lindl. (RC) extracts

Thunbergia laurifolia Lindl. (Acanthaceae) or Rang Chuet (RC) is described in traditional medicine for protection against dietary and environmental toxicants. This work, therefore, investigated RC's phytochemical profile, antimutagenic activity, and xenobiotic detoxification potential in its extracts. RC extracts were prepared by infusion with water, ethanol, acetone and subsequently assayed for major phytochemical constituents. Total phenolic content was 24.33, 5.65, and 1.42microg gallic acid equivalent (GAE) per mL for water, ethanol and acetone extract, respectively. HPLC analysis identified caffeic acid and apigenin as primary constituents of water extracts. Acetone and ethanol extracts contained primarily chlorophyll a and b, pheophorbide a, pheophytin a, and lutein. Treatment of Hepa 1C1C7 cells with standardized RC extracts resulted in a dose-dependent increase in QR specific activity for all extracts. Acetone extract (92microg GAE/mL) increased QR activity 2.8-fold, while ethanol (120microg GAE/mL) and water (1000microg GAE/mL) extracts increased QR activity by 1.35- and 1.56-fold, respectively. The RC extracts were subsequently assayed for mutagen and antimutagenic activity by bacterial reverse mutagenesis assay. All three RC extracts exhibited strong dose-dependent antimutagenic activity inhibiting 2-aminoanthracene induced mutagenesis up to 87% in Salmonella typhimurium TA 98. These results support the traditional medicinal use of RC for detoxification and suggest the potential role of both phenolic acids and natural chlorophyll constituents in modulating these effects.     

Bioactive Compounds and Encapsulation of Yanang (Tiliacora Triandra) Leaves

Background

Yanang (Tiliacora triandra) has been known as vegetable and herbal in northeast Thailand and Lao People''s Democratic Republic. Extracts from Yanang leaves contain high amounts of polyphenol constituents possessing antioxidant activity.

Materials and Methods

This work investigated bioactive compounds of Yanang extracts prepared by infusion with water, ethanol and acetone. Furthermore, this paper reports the design of the experimental method for optimization of Yanang encapsulation using three independent variables: the ratio of core material (Yanang), to wall material (gum Arabic), gum Arabic concentration and inlet temperature of spray drying on bioactive compounds stability. The stability of bioactive compounds was evaluated using phenolic compounds, total antioxidant, carotenoids and chlorophyll.

Results

The study of the bioactivity of Yanang extracts found that extraction with water was the appropriate application. The study of Yanang encapsulation demonstrated that gum Arabic, as coating agents, protected bioactive compounds of Yanang. Optimized condition for the encapsulation was at the ratio of core to wall {1:4}, in gum Arabic concentration 10% (w/v), and inlet temperature at 160▯C. The results show that the bioactive compounds were mainly affected by the ratio of core to wall material. Besides, moisture content and particle size of encapsulation depend on inlet temperature of spray drying, and gum Arabic concentration, respectively. This optimization reveals that the encapsulation process did not lose the bioactive compounds.

Conclusion

Yanang extract with water was the main phenolic compound and showed high antioxidant activities. This study demonstrates the potentials of using spray drying process and optimization for the encapsulation of herbal products.     

Neuroprotective effects of melatonin on amphetamine‐induced dopaminergic fiber degeneration in the hippocampus of postnatal rats

Chronic amphetamine (AMPH) abuse leads to damage of the hippocampus, the brain area associated with learning and memory process. Previous results have shown that AMPH‐induced dopamine neurotransmitter release, reactive oxygen species formation, and degenerative protein aggregation lead to neuronal death. Melatonin, a powerful antioxidant, plays a role as a neuroprotective agent. The objective of this study was to investigate whether the protective effect of melatonin on AMPH‐induced hippocampal damage in the postnatal rat acts through the dopaminergic pathway. Four‐day‐old postnatal rats were subcutaneously injected with 5‐10 mg/kg AMPH and pretreated with 10 mg/kg melatonin prior to AMPH exposure for seven days. The results showed that melatonin decreased the AMPH‐induced hippocampal neuronal degeneration in the dentate gyrus, CA1, and CA3. Melatonin attenuated the reduction in the expression of hippocampal synaptophysin, PSD‐95, α‐synuclein, and N‐methyl‐D‐aspartate (NMDA) receptor protein and mRNA caused by AMPH. Melatonin attenuated the AMPH‐induced reduction in dopamine transporter (DAT) protein expression in the hippocampus and the reduction in mRNA expression in the ventral tegmental area (VTA). Immunofluorescence demonstrated that melatonin not only prevented the AMPH‐induced loss of DAT and NMDA receptor but also prevented AMPH‐induced α‐synuclein overexpression in the dentate gyrus, CA1, and CA3. Melatonin decreased the AMPH‐induced reduction in the protein and mRNA of the NMDA receptor downstream signaling molecule, calcium/calmodulin‐dependent protein kinase II (CaMKII), and the melatonin receptors (MT1 and MT2). This study showed that melatonin prevented AMPH‐induced toxicity in the hippocampus of postnatal rats possibly via its antioxidative effect and mitochondrial protection.     

Electrical Conduction Properties of Hydrogenated Amorphous Carbon Films with Different Structures

Hydrogenated amorphous carbon (a-C:H) films have optical and electrical properties that vary widely depending on deposition conditions; however, the electrical conduction mechanism, which is dependent on the film structure, has not yet been fully revealed. To understand the relationship between the film structure and electrical conduction mechanism, three types of a-C:H films were prepared and their film structures and electrical properties were evaluated. The sp²/(sp² + sp³) ratios were measured by a near-edge X-ray absorption fine structure technique. From the conductivity–temperature relationship, variable-range hopping (VRH) conduction was shown to be the dominant conduction mechanism at low temperatures, and the electrical conduction mechanism changed at a transition temperature from VRH conduction to thermally activated band conduction. On the basis of structural analyses, a model of the microstructure of a-C:H that consists of sp² and sp³-bonded carbon clusters, hydrogen atoms and dangling bonds was built. Furthermore, it is explained how several electrical conduction parameters are affected by the carrier transportation path among the clusters.