The Spectroscopy Study of the Binding of an Active Ingredient of Dioscorea

Diosgenin (DIO) is the active ingredient of Dioscorea species. The interaction of DIO with bovine serum albumin (BSA) was investigated through spectroscopic methods under simulated physiological conditions. The fluorescence quenching data revealed that the binding of DIO to BSA without or with Co2+ or Zn2+ was a static quenching process. The presence of Co2+ or Zn2+ both increased the static quenching constants KSV and the binding affinity for the BSA-DIO system. In the sight of the competitive experiment and the negative values of ΔH0 and ΔS0, DIO bound to site I of BSA mainly through the hydrogen bond and Van der Waals’ force. In addition, the conformational changes of BSA were studied by Raman spectra, which revealed that the secondary structure of BSA and microenvironment of the aromatic residues were changed by DIO. The Raman spectra analysis indicated that the changes of conformations, disulfide bridges, and the microenvironment of Tyr, Trp residues of BSA induced by DIO with Co2+ or Zn2+ were different from that without Co2+ or Zn2+

Determinants of genetic structure in a highly heterogeneous landscape in southwest China

Intra-specific genetic diversity is a fundamental component of biodiversity, and is key to species adaptation and persistence. However, significant knowledge gaps still exist in our understanding of the patterns of genetic diversity and their key determinants. Most previous investigations mainly utilized single-species and/or a limited number of explanatory variables; so here we mapped the patterns of plastid genetic diversity within 15 plant species, and explored the key determinants shaping these patterns using a wide range of variables. Population-level cpDNA sequence data for 15 plant species from the Longitudinal Range Gorge Region (LRGR), southwest China, were retrieved from literature and used to estimate haplotype diversity (H(D)) and population pairwise genetic differentiation (F(ST)) indices. Genetic diversity and divergence landscape surfaces were then generated based on the H(D) and F(ST), respectively, to clarify the patterns of genetic structure in the region. Subsequently, we analyzed the relationships between plastid genetic diversity and 16 explanatory variables (classified as anthropogenic, climatic, and topographic). We found that the highest genetic diversity occurred in the Yulong Mountain region, with a significant proportion (~74.81%) of the high diversity land area being located outside of protected areas. The highest genetic divergence was observed approximately along the 25°N latitudinal line, with notable peaks in the western and eastern edges of the LRGR. Genetic diversity (H(D)) was weakly but significantly positively correlated with both Latitude (lat) and Annual Mean Wet Day Frequency (wet), yet significantly negatively correlated with all of Longitude (long), Annual Mean Cloud Cover Percent (cld), Annual Mean Anthropogenic Flux (ahf), and Human Footprint Index (hfp). A combination of climatic, topographic, and anthropogenic factors explained a significant proportion (78%) of genetic variation, with topographic factors (lat and long) being the best predictors. Our analysis identified areas of high genetic diversity (genetic diversity “hotspots”) and divergence in the region, and these should be prioritized for conservation. This study contributes to a better understanding of the features that shape the distribution of plastid genetic diversity in the LRGR and thus would inform conservation management efforts in this species-rich, but vulnerable region

Spatiotemporal maintenance of flora in the Himalaya biodiversity hotspot:Current knowledge and future perspectives

Mountain ecosystems support a significant one‐third of all terrestrial biodiversity, but our understanding of the spatiotemporal maintenance of this high biodiversity remains poor, or at best controversial. The Himalaya hosts a complex mountain ecosystem with high topographic and climatic heterogeneity and harbors one of the world's richest floras. The high species endemism, together with increasing anthropogenic threats, has qualified the Himalaya as one of the most significant global biodiversity hotspots. The topographic and climatic complexity of the Himalaya makes it an ideal natural laboratory for studying the mechanisms of floral exchange, diversification, and spatiotemporal distributions. Here, we review literature pertaining to the Himalaya in order to generate a concise synthesis of the origin, distribution, and climate change responses of the Himalayan flora. We found that the Himalaya supports a rich biodiversity and that the Hengduan Mountains supplied the majority of the Himalayan floral elements, which subsequently diversified from the late Miocene onward, to create today's relatively high endemicity in the Himalaya. Further, we uncover links between this Miocene diversification and the joint effect of geological and climatic upheavals in the Himalaya. There is marked variance regarding species dispersal, elevational gradients, and impact of climate change among plant species in the Himalaya, and our review highlights some of the general trends and recent advances on these aspects. Finally, we provide some recommendations for conservation planning and future research. Our work could be useful in guiding future research in this important ecosystem and will also provide new insights into the maintenance mechanisms underpinning other mountain systems

Helicobacter pylori infection is associated with decreased serum levels of high density lipoprotein, but not with the severity of coronary atherosclerosis

<p>Abstract</p> <p>Objective</p> <p>The objective of this survey was to study the association between <it>Helicobacter pylori </it>infection and the severity of coronary atherosclerosis.</p> <p>Methods</p> <p>The study population consisted of 961 consecutive patients (711 males and 250 females) who underwent coronary angiography for suspected or known coronary atherosclerosis. The patients' body mass index, blood pressure, the blood lipid, blood glucose, leukocyte count (10⁹/L), neutrophil count (10⁹/L), and Helicobacter <it>pylori</it>-specific IgG antibodies were performed. Coronary angiograms were scored according to vessel score and Gensini's score.</p> <p>Results</p> <p>A significant association between <it>H. pylori </it>infection and coronary atherosclerosis as well as its severity was not find in this cross section study (<it>p </it>= 0.858). And, the level distribution of vessel score (<it>p </it>= 0.906) and Gensini's score (<it>p </it>= 0.905) were similar in the seropositivity group and seronegativity group of Helicobacter <it>pylori </it>infection. However, the level of fasting high-density lipoprotein cholesterol (mmol/L) (<it>p </it>= 0.013) was significantly lower in the seropositivity group than that in the seronegativity group of Helicobacter <it>pylori </it>infection.</p> <p>Conclusions</p> <p>In conclusion, in the present study, a significantly correlation between Helicobacter <it>pylori </it>seropositivity and angiographically evaluated severity of atherosclerosis was not find. And, the present study showed a good correlation between Helicobacter <it>pylori </it>infection and decreased HDL cholesterol. However, the exact mechanisms need further study.</p

Unraveling the Novel Protective Effect of Patchouli Alcohol Against Helicobacter pylori-Induced Gastritis: Insights Into the Molecular Mechanism in vitro and in vivo

Patchouli alcohol (PA), a natural tricyclic sesquiterpene extracted from Pogostemon cablin (Blanco) Benth. (Labiatae), has been found to exhibit anti-Helicobacter pylori and anti-inflammatory properties. In this study, we investigated the protective effect of PA against H. pylori-induced gastritis in vitro and in vivo, and determined the underlying mechanism. In the in vivo experiment, a C57BL/6 mouse model of gastritis was established using H. pylori SS1, and treatments with standard triple therapy or 5, 10, and 20 mg/kg PA were performed for 2 weeks. Results indicated that PA effectively attenuated oxidative stress by decreasing contents of intracellular reactive oxygen species (ROS) and malonyldialdehyde (MDA), and increasing levels of non-protein sulfhydryl (NP-SH), catalase and glutathione (GSH)/glutathione disulphide (GSSG). Additionally, treatment with PA significantly attenuated the secretions of interleukin 1 beta (IL-1β), keratinocyte chemoattractant and interleukin 6 (IL-6). PA (20 mg/kg) significantly protected the gastric mucosa from H. pylori-induced damage. In the in vitro experiment, GES-1 cells were cocultured with H. pylori NCTC11637 at MOI = 100:1 and treated with different doses of PA (5, 10, and 20 μg/ml). Results indicated that PA not only significantly increased the cell viability and decreased cellular lactate dehydrogenase (LDH) leakage, but also markedly elevated the mitochondrial membrane potential and remarkably attenuated GES-1 cellular apoptosis, thereby protecting gastric epithelial cells against injuries caused by H. pylori. PA also inhibited the secretions of pro-inflammatory factors, such as monocyte chemotactic protein 1 (MCP-1), tumor necrosis factor-α (TNF-α) and IL-6. Furthermore, after PA treatment, the combination of NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) and cysteine-aspartic proteases 1 (CASPASE-1), the expression levels of NLRP3 inflammasome-related proteins, such as thioredoxin-interacting protein (TXNIP), pro-CASPASE-1, cle-CASPASE-1, and NLRP3 and genes (NLRP3 and CASPASE1) were significantly decreased as compared to the model group. In conclusion, treatment with PA for 2 weeks exhibited highly efficient protective effect against H. pylori-induced gastritis and related damages. The underlying mechanism might involve antioxidant activity, inhibition of pro-inflammatory factor and regulation of NLRP3 inflammasome function. PA exerted anti-H. pylori and anti-gastritis effects and thus had the potential to be a promising candidate for treatment of H. pylori-related diseases

Rapidity, azimuthal, and multiplicity dependence of mean transverse momentum and transverse momentum correlations in π+p\pi^{+}p and K+pK^{+}p collisions in s\sqrt{s}=22 GeV

Rapidity, azimuthal and multiplicity dependence of mean transverse momentum and transverse momentum correlations of charged particles is studied in pi/sup positive and K/sup positive collisions at 250 GeV/c incident beam momentum. For the first time, it is found that the rapidity dependence of the two-particle transverse momentum correlation is different from that of the mean transverse momentum, but both have similar multiplicity dependence. In particular, the transverse momentum correlations are boost invariant. This is similar to the recently found boost invariance of the charge balance function. A strong azimuthal dependence of the transverse momentum correlations originates from the constraint of energy-momentum conservation. The results are compared with those from the PYTHIA Monte Carlo generator. The similarities to and differences with the results from current heavy ion experiments are discussed

Yersinia pseudotuberculosis Exploits CD209 Receptors for Promoting Host Dissemination and Infection

Yersinia pseudotuberculosis is a Gram-negative enteropathogen and causes gastrointestinal infections. It disseminates from gut to mesenteric lymph nodes (MLNs), spleen, and liver of infected humans and animals. Although the molecular mechanisms for dissemination and infection are unclear, many Gram-negative enteropathogens presumably invade the small intestine via Peyer's patches to initiate dissemination. In this study, we demonstrate that Y. pseudotuberculosis utilizes its lipopolysaccharide (LPS) core to interact with CD209 receptors, leading to invasion of human dendritic cells (DCs) and murine macrophages. These Y. pseudotuberculosis CD209 interactions result in bacterial dissemination to MLNs, spleens, and livers of both wild-type and Peyer's patch-deficient mice. The blocking of the Y. pseudotuberculosis CD209 interactions by expression of 0-antigen and with oligosaccharides reduces infectivity. Based on the well-documented studies in which HIV-CD209 interaction leads to viral dissemination, we therefore propose an infection route for Y. pseudotuberculosis where this pathogen, after penetrating the intestinal mucosal membrane, hijacks the Y. pseudotuberculosis CD209 interaction antigen-presenting cells to reach their target destinations, MLNs, spleens, and livers.Peer reviewe