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Background: Diarrhea is an important ailment limiting the production of the Tibetan pig industry. Dynamic balance of the intestinal microbiota is important for the physiology of the animal. The objective of this work was to study fungal diversity in the feces of early weaning Tibetan piglets in different health conditions. Results: In the present study, we performed high-throughput sequencing to characterize the fungal microbial diversity in healthy, diarrheal and treated Tibetan piglets at the Tibet Autonomous Region of the People's Republic of China. The four alpha diversity indices (Chao1, ACE, Shannon and Simpson) revealed no significant differences in the richness across the different groups (P > 0.05). In all samples, the predominant fungal phyla were Ascomycota, Basidiomycota and Rozellomycota. Moreover, the healthy piglets showed a higher abundance of Ascomycota than the treated ones with a decreased level of Basidiomycota. One phylum (Rozellomycota) showed higher abundance in the diarrheal piglets than in the treated. At genus level, compared with that to the healthy group, the proportion of Derxomyces and Lecanicillium decreased, whereas that of Cortinarius and Kazachstania increased in the diarrheal group. The relative abundances of Derxomyces, Phyllozyma and Hydnum were higher in treated piglets than in the diarrheal ones. Conclusions: A decreased relative abundance of beneficial fungi (e.g. Derxomyces and Lecanicillium) may cause diarrhea in the early-weaned Tibetan piglets. Addition of probiotics into the feed may prevent diarrhea at this stage. This study presented the fungal diversity in healthy, diarrheal and treated early-weaned Tibetan piglets. [ABSTRACT FROM AUTHOR]

Aim: This Chinese study assessed partial pressure of exhaled nitric oxide (PeNO) in healthy Tibetan and non-Tibetan newborn infants born at a very high altitude. Methods: Full-term Tibetan and non-Tibetan neonates born in Lhasa, 3658 metres above sea level, were compared to non-Tibetan neonates born in Kunming (1891 m) and Huai'an (16 m). The chemiluminiscence technique was used to measure the fraction of exhaled nitric oxide during spontaneous tidal breathing and this was then converted to partial pressure of exhaled nitric oxide (PeNO). Results: In their first week, Tibetan and non-Tibetan neonates born in Lhasa had persistently higher PeNO levels than non-Tibetan neonates born in Kunming and Huai'an, which was further verified by partial pressure of inspired oxygen adjustment. However, the non-Tibetans born in Lhasa required short-term oxygen therapy to improve their early postnatal oxygenation. The temporal changes of PeNO and cardio-respiratory function measurements demonstrated that Tibetan and non-Tibetan newborns in Lhasa initially needed to adapt to attain homoeostasis in oxygenation and gas exchange. Conclusion: Tibetan and non-Tibetan newborn infants living at the same high altitude demonstrated comparable PeNO levels during postnatal adaptation to hypobaric hypoxia, which warrants further investigation of the mechanism of endogenous nitric oxide and hypoxic tolerance. [ABSTRACT FROM AUTHOR]

Abstract: Greenhouse pot experiments were conducted to investigate genotypic differences in response to individual and combined stresses of drought and salinity between Tibetan wild barley genotypes (XZ5, drought-tolerant; XZ16, salinity/aluminum tolerant) and cv. CM72 (salinity-tolerant). Either drought (D) or salinity (S) alone and in combination (D + S) stresses significantly decreased plant growth, chlorophyll content, net photosynthetic rate (Pn), maximal photochemical efficiency of PSII (Fv/Fm), water potential and osmotic potential, with the largest suppression under combined stress, and two wild genotypes showing more tolerance than CM72. Water use efficiency (WUE) increased significantly in XZ5 and XZ16 after D + S, but no significant change in CM72. XZ5 and XZ16 showed 30.9% and 12.1% higher K+ level and 30.5% and 24.1% lower Na+/K+ ratio in plants, compared with CM72, with increased metal nutrients as Ca, Fe and Mn under D + S. The peak accumulation in proline and glycine-beatine was recorded in combined stress with larger accumulation in two wild genotypes. Moreover, larger increases in the level of ASA and GSH, and the activities of Ca2+Mg2+-ATPase, and superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), guaiacol peroxidase (POD) and glutathione reductase (GR) under D + S vs control were observed in XZ5 and XZ16 than CM72, with less accumulation of H2O2 and malondialdehyde. These results suggest that high tolerance to D + S stress of XZ5 and XZ16 is closely related to lower Na+/K+ ratio and enhanced Ca2+Mg2+-ATPase, proline, glycine-beatine and WUE, and improved capacity of antioxidative performance to scavenge reactive oxygen species and thus suppressed level of lipid peroxidation. [Copyright &y& Elsevier]

Tibetans have lived at very high altitudes for thousands of years, and they have a distinctive suite of physiological traits that enable them to tolerate environmental hypoxia. These phenotypes are clearly the result of adaptation to this environment, but their genetic basis remains unknown. We report genome-wide scans that reveal positive selection in several regions that contain genes whose products are likely involved in high-altitude adaptation. Positively selected haplotypes of EGLN1 and PPARA were significantly associated with the decreased hemoglobin phenotype that is unique to this highland population. Identification of these genes provides support for previously hypothesized mechanisms of high-altitude adaptation and illuminates the complexity of hypoxia-response pathways in humans. [ABSTRACT FROM AUTHOR]

The article discusses hypoxic pathophysiology and high-altitude medicine in Tibet, China as of December 2012, with a focus on the dynamics of Tibetan adaptations to high-altitude environments and lesions in the cardiovascular system. Topics include diseases such as mountain sickness and hypoxia pulmonary hypertension, hypoxia's effect on blood flow and relation to coronary artery disease (CAD), and bradycardia risk factors. Additional information is presented on right heart catheterization and systemic blood pressure.