Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Tibet”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed1991

[Hemoglobin phenotype of native residents in Tibet and structural analysis of HbE].

In this paper, the hemoglobin phenotype of 3,711 cases of native residents (Tibetan, 3,451 cases; Menba, 148 cases and LuoBa ethnic group, 122 cases) and 478 cases of immigrants. (totalling 4,190 cases), in 3 different sea-levels of the Autonomous Region of Tibet (Naqu-Ando, Lhasa-Rikeze and Lingzhi districts), are described. 11 cases (1 case in Tibetan, 6 cases in MenBa and 4 cases in LuoBa ethnic group) of slow-moving abnormal Hb were found. The mean incidence of abnormal Hb in the native residents was 2.98/1000. The incidence in MenBa and LuoBa ethical groups was remarkably higher than that in Tibetan. Besides, the Hb phenotypes of native residents were HbA, HbA2 and HbF. Structural analysis of the abnormal Hb by micro-crystal cellulose membrane and high performance liquid chromatography (HPLC) demonstrated that all the 11 cases of Hb variant in the native residents are HbE [ beta 26 (B8) Glu----Lys]. The distribution and characteristics of the abnormal Hb in Tibet are discussed.

Adolescent↗
PubMed1989

[Morphology and histology of the placenta from parturients of various nationalities in the Tibet plateau].

The morphology and histology of placentae from Tibet have been studied and reported in this article. The subjects studied were 51 Tibetan women and 19 Han women who were healthy and pregnant 38 to 42 weeks. The Han women had migrated to Tibet plateau from the plains. It showed that Tibetan women had newborns of significantly higher birth weight and lighter placentae and also a higher positive rate than Han woman in syncytial nodes, vascular syncytial membranes, vascular proliferation and cellulose-like necroses. There was a very significant difference between women living at high-altitude and women living at sea-level in most parameters.

Adult↗
PubMed2025

Genomic analysis of Dasiphora on the Qinghai-Tibet Plateau provides insights into genetic divergence and flower color variation.

The Qinghai-Tibet Plateau (QTP) harbors diverse alpine flora, including the ecologically significant shrubs Dasiphora fruticosa and D. glabra, for which taxonomic uncertainties remain and adaptive mechanisms are still poorly understood. Based on high-quality genome assembly, population resequencing, and multi-omics integration, we elucidated their evolutionary divergence and flower color genetics. Chromosome-level haplotype-resolved genomes were assembled: autotetraploid D. fruticosa (929.99 Mb) and diploid D. glabra (450.89 Mb). Phylogenetic analysis showed that the tetraploid D. fruticosa and D. glabra in this study clustered together, while the diploid D. fruticosa sequenced by previous research formed a distinct lineage clustered outside. Consistently, population structure analysis of 55 samples revealed three major clades, with D. fruticosa further subdivided into two divergent branches. Additionally, hybridization events detected by Admixture, coupled with ploidy complexity identified via flow cytometry highlight the intricate genetic relationships within this genus. Adaptive gene families expanded in antioxidant (flavonoid synthesis) and secondary metabolism pathways, adapting to ultraviolet radiation and cold stress. Natural selection analysis identified 193 candidate genes (e.g., TFB5 in the DNA repair pathway), predominantly localized to chromosome 5, which are potential candidates for high-altitude adaptation. Transcriptome and metabolome analyses showed D. fruticosa's yellow petals derive from flavonol (quercetin) accumulation, while D. glabra's white petals result from proanthocyanidin biosynthesis via high LAR/ANR expression. This study provides insights into the taxonomic revision and adaptive genetic divergence of alpine plants, and offers a foundation for horticultural improvement of Dasiphora.

Flowers↗
PubMed2002

Microorganisms in a high altitude glacier ice in Tibet.

Eighty-one strains of viable microorganisms were recovered from 23 samples collected from Ice Core 3 of Malan Glacier (China, 91 degrees 45.3' E, 35 degrees 48.4' N) drilled at high altitude (5620 m). All the strains were prokaryotes--75 of bacteria (including spore-forming ones) and 6 of actinomycetes. The characteristic genera differ from those of Arctic and Antarctic ice, in which many fungi and algae are widely distributed; this shows an difference of environmental conditions between Tibet and polar regions. The variation in number and species of Bacillus in different ice core layers implied changes of environmental conditions in the past.

Bacteria↗
PubMed2003

Analysis of genetic diversity of hordein in wild close relatives of barley from Tibet.

We analyzed genetic diversity in the storage protein hordein encoded at Hor-1, Hor-2 and Hor-3 loci in seeds from 211 accessions of wild close relatives of barley, Hordeum vulgare ssp. agriocrithon and H. vulgare ssp. spontaneum. Altogether 32, 27 and 13 different phenotypes were found for Hor-1, Hor-2 and Hor-3, respectively. A comparison of our results with those of previous studies indicates that Tibetan samples reflect the highest diverse level of hordein phenotypes when compared to samples from Israel and Jordan. This high degree of polymorphism supports the hypothesis that Tibet is one of the original centers of H. vulgare L.

Electrophoresis, Polyacrylamide Gel↗
PubMed2001

Anthropometry and clinical features of Kashin-Beck disease in central Tibet.

We compared two different populations living in central Tibet with the purpose of establishing standard values for different anthropometric parameters in a rural population. Later on, these values were used as references for a similar study on a KBD population. One group (KBD) (n=1,246) came from the endemic areas, and the other group, serving as the control population (n=815), came from non-endemic areas. Both groups included children and adults and were of the Mongoloid type; they were farmers or semi-nomads. Height, weight, segment length, joint perimeter, joint diameter, joint movement were recorded. Also more subjective information such as general feeling of tiredness, rapid fatigue at work, work limitation, joint pain, muscle weakness, muscular atrophy, dwarfism, flatfoot, and waddling gate was also collected. Those variables were compared between the two groups.

Adolescent↗
PubMed2001

Effects of physical therapy on patients with Kashin-Beck disease in Tibet.

A clinical trial of physical therapy treatment for patients suffering from Kashin-Beck disease (KBD) has been carried out in Tibet. One-hundred and thirty-five patients with Kashin-Beck disease were allocated to either physical therapy (72 patients) or prescription of multivitamins (63 patients). The patients were followed for 4 years. This study suggested a beneficial effect of physical treatment.

Adolescent↗
PubMed1997

Clinical manifestations of Kashin-Beck disease in Nyemo Valley, Tibet.

Clinical manifestations of Kashin-Beck disease have been studied in Central Tibet. Statistical analysis of physical signs allowed a definition of the clinical diagnosis and a scale for the functional severity for the disease to be drawn up. This classification is used for the assessment of patients who received palliative physical treatment. A group of 136 patients have been examined and their disabled joints classified according to pain, bony enlargement and restriction of movement. 57% were between 20 and 35 years of age. The patients mainly complained about their distal weightbearing joints. The clinical evolution of the disease is described from childhood to adult life.

Adolescent↗
PubMed2001

Epidemiological support for a multifactorial aetiology of Kashin-Beck disease in Tibet.

We carried out a cross-sectional study in 12 rural villages in order to identify the risk factors for Kashin-Beck disease in Tibet. Children aged 5-15 years (n=575) were examined and their corresponding houses were visited. Samples were collected in order to study fungal contamination of stored grain and the organic matter content of drinking water. Multivariate analysis was performed using logistic regression and population attributable fractions were computed to estimate the impact of each factor. The following variables were independently associated with the disease: age, gender, low socio-economic status, indicators of a poorly diversified diet, iodine deficiency and small water container size (with higher organic matter levels in small containers). Selenium deficiency was severe in all study subjects. The degree of fungal contamination of barley grain was related to the highest percentage of cases (65%) in a sample of the study population. Higher urinary iodine levels were not associated with decreasing prevalence rates when Alternaria sp. was isolated. The data that we report supports the hypothesis that Kashin-Beck disease occurs as a consequence of oxidative damage to cartilage and bone cells when associated with decreased antioxidant defence. Another mechanism that may coexist is bone remodelling stimulated by thyroid hormones whose actions can be blocked by certain mycotoxins.

Adolescent↗
PubMed1997

Another pedigree with pure autosomal dominant spastic paraplegia (AD-FSP) from Tibet mapping to 14q11.2-q24.3.

The mutant in a family with autosomal-dominant spastic paresis in Northern Tibet was mapped by linkage analysis with several microsatellite markers to a gene locus at 14q11.2-q24.3, an area to which a few mutants leading to a condition with similar clinical signs have previously been mapped. The mutant observed in this pedigree probably arose de novo. Gene loci at 2p21-p24 and 15q, which have been found for other pedigrees with dominant spastic paresis, were excluded. The data in this pedigree do not contradict the hypothesis proposed by another group that there might be anticipation.

Adult↗
PubMed2006

A preliminary survey of the arbuscular mycorrhizal status of grassland plants in southern Tibet.

We report for the first time the arbuscular mycorrhizal (AM) status of native plant species and AM fungal diversity in the grasslands of southern Tibet. A total of 51 soil samples were collected from the rhizospheres of the dominant plant species, and AM fungal structures were observed in 18 (82%) of 22 plant species examined. Vesicles and aseptate hyphae were the structures most frequently observed in the plant roots. After trap culture for 5 months, 25 AM fungal taxa were identified in the soil samples collected, of which nine belonged to Glomus, ten to Acaulospora, one to Entrophospora and five to Scutellospora. The frequency of occurrence of different genera and species varied greatly. Glomus was the dominant genus, and the most frequent and abundant species was Glomus mosseae. Over the whole sampling area, spore density in the rhizosphere soil of different host plant species ranged from 2 to 66 per 20 g air-dried soil. Overall AM fungal species richness was 2.10 and species diversity was 2.35. AM fungal diversity was also compared among the four different land use types (farmland and normal, disturbed and highly disturbed montane scrub grassland). Spore densities in the farmland and normal grassland were much higher than in the grasslands that had been degraded to varying degrees. The species richness in normal grassland was the highest of the four land use types examined. Species diversity varied from 1.99 to 0.94 and was highest in normal grassland, intermediate in degraded grassland and farmland, and lowest in the highly disturbed grassland.

Biodiversity↗
PubMed2005

RAPD profiling in detecting genetic variation in endemic Coelonema (Brassicaceae) of Qinghai-Tibet Plateau of China.

Random amplified polymorphic DNA (RAPD) markers were used to measure genetic diversity of Coelonema draboides (Brassicaceae), a genus endemic to the Qilian Mountains of the Qinghai-Tibet Plateau. We sampled 90 individuals in 30 populations of Coelonema draboides from Datong and Huzhu counties of Qinghai Province in P.R. China. A total of 186 amplified bands were scored from the 14 RAPD primers, with a mean of 13.3 amplified bands per primer, and 87% (161 bands) polymorphic bands (PPB) was found. Analysis of molecular variance (AMOVA) shows that a large proportion of genetic variation (84.2%) resides among individuals within populations, while only 15.8% resides among populations. The species shows higher genetic diversity between individuals than other endemic and endangered plants. The RAPDs provide a useful tool for assessing genetic diversity of rare, endemic species and for resolving relationships among populations. The results show that the genetic diversity of this species is high, possibly allowing it to adapt more easily to environmental variations. The main factor responsible for the high level of differentiation within populations and the low level of diversity among populations is probably the outcrossing and long-lived nature of this species. Some long-distance dispersal, even among far separated populations, is also a crucial determinant for the pattern of genetic variation in the species. This distributive pattern of genetic variation of C. draboides populations provides important baseline data for conservation and collection strategies for the species. It is suggested that only populations in different habitats should be studied and protected, not all populations, so as to retain as much genetic diversity as possible.

Brassicaceae↗
PubMed2007

Patterns of genetic variation in Swertia przewalskii, an endangered endemic species of the Qinghai-Tibet Plateau.

Swertia przewalskii Pissjauk. (Gentianaceae) is a critically endangered and endemic plant of the Qinghai-Tibet Plateau in China. RAPD and ISSR analyses were carried out on a total of 63 individuals to assess the extent of genetic variation in the remaining three populations. Percentage of polymorphic bands was 94% (156 bands) for RAPD and 96% (222 bands) for ISSR. A pairwise distance measure calculated from the RAPD and ISSR data was used as input for analysis of molecular variance (AMOVA). AMOVA indicated that a high proportion of the total genetic variation (52% for RAPD and 56% for ISSR) was found among populations; pairwise Phi (ST) comparisons showed that the three populations examined were significantly different (p < 0.001). Significant genetic differentiation was found based on different measures (AMOVA and Hickory theta(B)) in S. przewalskii (0.52 on RAPD and 0.56 on ISSR; 0.46 on RAPD and 0.45 on ISSR). The differentiation of the populations corresponded to low average gene flow (0.28 based on RAPD and 0.31 based on ISSR), whereas genetic distance-based clustering and coalescent-based assignment analyses revealed significant genetic isolation among populations. Our results indicate that genetic diversity is independent of population size. We conclude that although sexual reproduction and gene flow between populations of S. przewalskii are very limited, they have preserved high levels of genetic diversity. The main factors responsible for the high level of difference among populations are the isolation and recent fragmentation under human disturbance.

China↗
PubMed2005

Allele frequencies of 15 STR loci of Luoba ethnic group in Tibet (Southwestern China).

Allele frequency data for 15 short tandem repeat (STR) loci included in the AmpFlSTR Identifiler kit were obtained from a sample of 93 healthy unrelated individuals of Luoba population born in Tibet Autonomy Region of China (Southwestern China). In these samples, 141 alleles and 365 genotypes were observed for 15 STR loci. The distribution of these observed genotypes were not significantly different from the expected distribution according to Hardy-Weinberg equilibrium.

DNA Fingerprinting↗
PubMed2006

Allele frequencies of 15 STR loci of Tibetan lived in Tibet Lassa.

Allele frequency data for 15 Short Tandem Repeat (STR) loci included in the AmpFl STR Identifiler kit were obtained from a sample of 196 healthy unrelated individuals of Tibetan born in Lassa of Tibet Autonomy Region of China (SW China). The distribution of these observed genotypes were not significantly different from the expected distribution according to Hardy-Weinberg equilibrium.

Asian People↗
PubMed2006

Genetic polymorphisms of 15 STR loci in two Tibetan populations from Tibet Changdu and Naqu, China.

The allelic distribution of 15 short tandem repeat (STR) loci included in the AmpFl STR Identifiler kit was examined in 100 Changdu Tibetan and 118 Naqu Tibetan unrelated individuals living in the Tibet Province, PR China. The distribution of these observed genotypes was not significantly different from the expected distribution according to Hardy-Weinberg equilibrium.

DNA Fingerprinting↗
PubMed2006

Y chromosome STR haplotypes of Tibetan Living Tibet Lassa.

Allele frequencies and haplotypes of the 17 Y-chromosome STRs loci, namely DYS19, DYS385a/b, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635 (YGATA C4), and YGATA H4 were determined in a sample of 131 healthy unrelated males from the Lassa area of Tibet Autonomy Region of China (SW China). In 131 samples 106 different haplotypes were encountered, of which 105 were observed only once. The overall haplotype diversity was 0.9998. The results demonstrate that these loci will be very useful for human identification in forensic cases and paternity tests in the Lassa region.

Chromosomes, Human, Y↗