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1.
Geographical variability of alpha-1-antitrypsin alleles in China: A study on six Chinese populations
Ying Qi-long Zhang Mei-lin Liang Chih-chuan Liu Xiao-po Huang You-wen Wang Rong-xin Zhang Ni-jia Chen Li-chang Chen Luo-fu Yu Ning-chang Muo Xi-ping 《Human genetics》1985,69(2):184-187
Summary Alpha-1-antitrypsin phenotypes of six Chinese Han populations (20°–45°N. latitude) were determined. The frequency of allele M2 increases from North to South China. The north-south change of M2 appears to be mainly at the expense of alleles M1 and M3. Geographical variability of other variants was also observed. In the northern populations, the most common variants are M4 and Etokyo; in the southern populations, Pweishi, a variant which can not be distinguished electrophoretically from Pyasugi. These results form a distribution pattern of alpha-1-antitrypsin alleles in China. 相似文献
2.
The phylogeny of Greya Busck (Lepidoptera: Prodoxidae) was inferred from
nucleotide sequence variation across a 765-bp region in the cytochrome
oxidase I and II genes of the mitochondrial genome. Most parsimonious
relationships of 25 haplotypes from 16 Greya species and two outgroup
genera (Tetragma and Prodoxus) showed substantial congruence with the
species relationships indicated by morphological variation. Differences
between mitochondrial and morphological trees were found primarily in the
positions of two species, G. variabilis and G. pectinifera, and in the
branching order of the three major species groups in the genus. Conflicts
between the data sets were examined by comparing levels of homoplasy in
characters supporting alternative hypotheses. The phylogeny of Greya
species suggests that host-plant association at the family level and larval
feeding mode are conservative characters. Transition/transversion ratios
estimated by reconstruction of nucleotide substitutions on the phylogeny
had a range of 2.0-9.3, when different subsets of the phylogeny were used.
The decline of this ratio with the increase in maximum sequence divergence
among taxa indicates that transitions are masked by transversions along
deeper internodes or long branches of the phylogeny. Among transitions,
substitutions of A-->G and T-->C outnumbered their reciprocal
substitutions by 2-6 times, presumably because of the approximately 4:1
(77%) A+T-bias in nucleotide base composition. Of all transversions,
73%-80% were A<-->T substitutions, 85% of which occurred at third
positions of codons; these estimates did not decrease with an increase in
maximum sequence divergence of taxa included in the analysis. The high
frequency of A<-->T substitutions is either a reflection or an
explanation of the 92% A+T bias at third codon positions.
相似文献
3.
A wide-ranging examination of plastid (pt)DNA sequence homologies within
higher plant nuclear genomes (promiscuous DNA) was undertaken. Digestion
with methylation-sensitive restriction enzymes and Southern analysis was
used to distinguish plastid and nuclear DNA in order to assess the extent
of variability of promiscuous sequences within and between plant species.
Some species, such as Gossypium hirsutum (cotton), Nicotiana tabacum
(tobacco), and Chenopodium quinoa, showed homogenity of these sequences,
while intraspecific sequence variation was observed among different
cultivars of Pisum sativum (pea), Hordeum vulgare (barley), and Triticum
aestivum (wheat). Hypervariability of plastid sequence homologies was
identified in the nuclear genomes of Spinacea oleracea (spinach) and Beta
vulgaris (beet), in which individual plants were shown to possess a unique
spectrum of nuclear sequences with ptDNA homology. This hypervariability
apparently extended to somatic variation in B. vulgaris. No sequences with
ptDNA homology were identified by this method in the nuclear genome of
Arabidopsis thaliana.
相似文献
4.
Increasing evidence indicates that end-stage renal disease (ESRD) is associated with the morbidity of cancer. However, whether different dialysis modality and sex effect modify the cancer risks in ESRD patients remains unclear. A total of 3,570 newly diagnosed ESRD patients and 14,280 controls matched for age, sex, index month, and index year were recruited from the National Health Insurance Research Database in Taiwan. The ESRD status was ascertained from the registry of catastrophic illness patients. The incidence of cancer was identified through cross-referencing with the National Cancer Registry System. The Cox proportional hazards model and the Kaplan-Meier method were used for analyses. A similar twofold increase in cancer risk was observed among ESRD patients undergoing hemodialysis (HD) or peritoneal dialysis (PD) after adjusting for other potential risk factors. Patients with the highest cancer risk, approximately fourfold increased risk, were those received renal transplants. Urothelial carcinoma (UC) had the highest incidence in HD and PD patients. However, renal cell carcinoma (RCC) had the highest incidence in the renal transplantation (RT) group. In addition, female patients undergoing RT or PD had a higher incidence of RCC and UC, respectively. Male patients under HD had both higher incidence of RCC and UC. In conclusion, different dialysis modality could modify the cancer risks in ESRD patients. We also found sex effect on genitourinary malignancy when they are under different dialysis modality. 相似文献
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6.
JN Matthiessen 《Australian Journal of Entomology》1999,38(4):348-353
In field and laboratory studies, mortality of African black beetle, Heteronychus arator, in the winter-rainfall, Mediterranean-type climate region of south-western Australia was higher in the late immature stages during summer than in the early immature stages that occur during spring, a contrast to summer-rainfall climatic regions. Greatest mortality occurred around the pupal stage in contrasting soil types, despite drying differences in summer and supplementary watering in some plots. Sampling of natural populations confirmed experimental results that mortality in late immature stages is the major factor limiting H. arator populations under a Mediterranean-type climate. Inter-generation increase in H. arator abundance was uncommon, explaining the consistent abundance typically observed between years in south-western Australia. Random dispersal of newly emerged adults in autumn was inferred to restore uniformity in adult abundance between areas of varying favourability for immature survival. 相似文献
7.
Background
The aim of this study was to evaluate a possible association between malignancy and anxiety disorders (AD) in Taiwan.Methods
We employed data from the National Health Insurance system of Taiwan. The AD cohort contained 24,066 patients with each patient randomly frequency matched according to age and sex with 4 individuals from the general population without AD. Cox''s proportional hazard regression analysis was conducted to estimate the influence of AD on the risk of cancer.Results
Among patients with AD, the overall risk of developing cancer was only 1% higher than among subjects without AD, and the difference was not significant (hazard ratio [HR] = 1.01, 95% confidence interval [95% CI] = 0.95–1.07). With regard to individual types of cancer, the risk of developing prostate cancer among male patients with AD was significantly higher (HR = 1.32, 95% CI = 1.02–1.71). On the other hand, the risk of cervical cancer among female patients with AD was marginally significantly lower than among female subjects without AD (HR = 0.72, 95% CI = 0.51–1.03).Limitations
One major limitation is the lack of information regarding the life style or behavior of patients in the NHI database, such as smoking and alcohol consumption.Conclusions
Despite the failure to identify a relationship between AD and the overall risk of cancer, we found that Taiwanese patients with AD had a higher risk of developing prostate cancer and a lower risk of developing cervical cancer. 相似文献8.
Wen-Yuan Lee Li-Min Sun Ming-Chia Lin Ji-An Liang Shih-Ni Chang Fung-Chang Sung Chih-Hsin Muo Chia-Hung Kao 《PloS one》2012,7(12)
Background
Controversy still exists regarding whether alendronate (ALN) use increases the risk of esophageal cancer or breast cancer.Methods
This paper explores the possible association between the use of oral ALN in osteoporosis patients and subsequent cancer risk using the National Health Insurance (NHI) system database of Taiwan with a Cox proportional-hazard regression analysis. The exposure cohort contained 5,624 osteoporosis patients used ALN and randomly frequency-matched by age and gender of 3 osteoporosis patients without any kind of anti-osteoporosis drugs in the same period.Results
For a dose ≥1.0 g/year, the risk of developing overall cancer was significantly higher (hazard ratio: 1.69, 95% confidence ratio: 1.39–2.04) than in osteoporosis patients without any anti-osteoporosis drugs. The risks for developing liver, lung, and prostate cancers and lymphoma were also significantly higher than in the control group.Conclusions
This population-based retrospective cohort study did not find a relationship between ALN use and either esophageal or breast cancer, but unexpectedly discovered that use of ALN with dose ≥1.0 g/year significantly increased risks of overall cancer incidence, as well as liver, lung, and prostate cancers and lymphoma. Further large population-based unbiased studies to enforce our findings are required before any confirmatory conclusion can be made. 相似文献9.
10.
I-Kuan Wang Chih-Hsin Muo Yi-Chih Chang Chih-Chia Liang Chiz-Tzung Chang Shih-Yi Lin Tzung-Hai Yen Feng-Rong Chuang Pei-Chun Chen Chiu-Ching Huang Chi-Pang Wen Fung-Chang Sung Donald E. Morisky 《CMAJ》2013,185(3):207-213