Antitubercular and antiplasmodial constituents of Abrus precatorius

A known isoflavanquinone, abruquinone B ( 1), and a new derivative, abruquinone G ( 2), were isolated from the aerial parts of Abrus precatorius. Chemical structures of these compounds were elucidated by spectral analyses. While 1 exhibited antitubercular, antiplasmodial and cytotoxic activities, compound 2 showed mild antiviral and cytotoxic activities.     

Inhibitory effects of Thai plants β-glycosides on <Emphasis Type="Italic">Trichomonas vaginalis</Emphasis>

Trichomoniasis is now an important health problem in developing countries. Although metronidazole has so far been widely used to treat this disease, the prevalence of metronidazole-resistant protozoa and unpleasant adverse effects have been found. In this study, natural products purified from Thai plants were, therefore, investigated for their effectiveness against Trichomonas vaginalis. The minimal inhibitory concentrations for all beta-glycosides against Trichomonas vaginalis at 24 h were in a range of 6.25-12.5 microM. In addition, torvoside A and H were found to be more potent than their corresponding aglycones, deglucosylated torvoside A and H, while other beta-glycosides were generally as active as their corresponding aglycones. The cytotoxicity of these compounds was also determined. Except for dalcochinin, none of the tested compounds showed cytotoxicity against Vero and cancer cell lines (KB and MCF-7), having IC(50) values greater than 50 microg/ml. In conclusion, beta-glycosides and several aglycones showed selective inhibition against Trichomonas vaginalis without harmful effect to mammalian cells.     

Internalization and propagation of the dengue virus in human hepatoma (HepG2) cells

OBJECTIVES: This study sought to undertake a comparative analysis of the internalization and propagation of all four dengue serotypes in a single cell line of human liver origin, HepG2. METHODS: Virus production after infection was determined by the plaque assay technique. Internalization profiles were determined by incubating virus and cells on ice and then raising the temperature for various times. The contribution of extracellular matrix components to internalization was determined by pretreatment of cells with either trypsin or heparinase III. RESULTS: HepG2 cells were able to support the propagation of all four serotypes with mature viruses being produced by 12 h for dengue serotype 4 and by 17-18 h for the remaining serotypes. Virus internalization showed a plateau for serotypes 1, 2 and 4 entry while serotype 3 showed a constant increase in internalization for up to 5 h. Pretreatment of HepG2 cells with heparinase III or trypsin both resulted in a reduction in viral production, with the smallest effect being noted for dengue serotype 3. CONCLUSION: These results suggest that the interaction between the dengue virus and liver cells is a complex one that requires both protein and nonprotein elements, and has a significant serotype/strain element.     

Body image dissatisfaction in pregnant and non-pregnant females is strongly predicted by immune activation and mucosa-derived activation of the tryptophan catabolite (TRYCAT) pathway

Objectives: The aim of the present study is to delineate the associations between body image dissatisfaction in pregnant women and immune-inflammatory biomarkers, i.e., C-reactive protein (CRP), zinc and IgA/IgM responses to tryptophan and tryptophan catabolites (TRYCATs).

Methods: We assessed 49 pregnant and 24 non-pregnant females and assessed Body Image Satisfaction (BIS) scores at the end of term (T1), and 2–4 days (T2) and 4–6 weeks (T3) after delivery. Subjects were divided in those with a lowered BIS score (≤?3) versus those with a higher score.

Results: Logistic regression analysis showed that a lowered T1 BIS score was predicted by CRP levels and IgA responses to tryptophan (negative) and TRYCATs (positive), perinatal depression, body mass index (BMI) and age. The sum of quinolinic acid, kynurenine, 3-OH-kynurenine and 3-OH-anthranilic acid (reflecting brain quinolinic acid contents) was the single best predictor. In addition, a large part of the variance in the T1, T2 and T3 BIS scores was explained by IgA responses to tryptophan and TRYCATs, especially quinolinic acid.

Conclusions: Body image dissatisfaction is strongly associated with inflammation and mucosa-derived IDO activation independently from depression, pregnancy, BMI and age. IgA responses to peripheral TRYCATs, which determine brain quinolinic acid concentrations, also predict body image dissatisfaction.     

Transport of the natural sweetener stevioside and its aglycone steviol by human organic anion transporter (hOAT1; SLC22A6) and hOAT3 (SLC22A8)

The natural sweetening agent stevioside and its aglycone metabolite, steviol, have been shown to inhibit transepithelial transport of para-aminohippurate (PAH) in isolated rabbit renal proximal tubules by interfering with basolateral entry. The aim of the present study was to determine which of the cloned basolateral organic anion transporters were involved in the renal transport of stevioside and steviol. This question was addressed in Xenopus laevis oocytes expressing human organic anion transporter 1 (hOAT1), 3 (hOAT3), and winter flounder OAT (fOat1). The parent compound, stevioside, had no inhibitory effect on either PAH (hOAT1) or ES (estrone sulfate; hOAT3) uptake. In contrast, steviol showed significant, dose-dependent inhibition of PAH and ES uptake in hOAT1- or hOAT3-expressing oocytes, respectively. The IC(50) of steviol for hOAT1-mediated PAH transport was 11.1 microM compared with 62.6 microM for hOAT3-mediated ES uptake. The Michaelis-Menten inhibition constants (K(i)) for steviol transport mediated by hOAT1 and hOAT3 were 2.0 +/- 0.3 and 5.4 +/- 2.0 microM, respectively. Trans-stimulation of PAH efflux by steviol was assessed to determine whether steviol itself was transported by hOAT1 or hOAT3. A low concentration of 1 microM steviol increased the efflux of [(3)H]PAH (trans-stimulated) via both hOAT1 and hOAT3. In addition, it was shown by electrophysiology that steviol entry induced inward current in fOat1-expressing oocytes. In conclusion, stevioside had no interaction with either hOAT1 or hOAT3, whereas hOAT1, hOAT3, and fOat1 were all shown to be capable of steviol transport and thus, can play a role in its renal transport and excretion.     

Challenging times: ethics,nursing and the COVID-19 pandemic

Globally nurses and midwives are working hard to detect cases of COVID-19, to save lives or give comfort in the face of death, to educate themselves and the public about protective measures to stop the viral spread, while still caring for those not infected with the virus. In many countries nurses are working under virtual siege from this pandemic, with not enough resources or personal protective equipment, overwhelming numbers of patients, staff shortages, underprepared health systems and supply chain failures. Nurses and other health and emergency workers are suffering physical and emotional stress, and moral distress from conflicting professional values. They are faced with unpalatable and complex ethical issues in practice, with moral conflicts, high levels of acuity and patient deaths, and long working hours. A rising number of nurses are infected with SARS-CoV-2 or dying in the line of duty. Nurses need strong moral courage, stamina and resilience to work on the front lines of the pandemic, often while separated from their loved ones.     

A survey of the Th2R and Th3R allelic variants in the circumsporozoite protein gene of P. falciparum parasites from western Thailand

Allelic variation in the Plasmodium falciparum circumsporozoite protein (CS) gene has been determined by sequencing the immunodominant T-cell epitopes, Th2R and Th3R, from 95 isolates from two malaria-endemic areas in the west of Thailand. Comparison with a reference sequence revealed only non-synonymous point mutations in the two epitope regions. Point mutations were found outside these epitopes in a minority of samples, and all but four were also non-synonymous. A relatively high number of variants, 11 Th2R and 9 Th3R, were detected and comprised some that had not been previously observed. However, the Th2R*05 and the Th3R*01 allelic variants predominated, as they were found in more than 70% of the 101 sequences obtained.