首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 721 毫秒
1.
A large literature documents a widespread prevalence of small stature among Indian children as well as adults. We show that a height gap relative to a richer population such as whites in England also exists, although substantially reduced, among adult immigrants of Indian ethnicity in England. This is despite positive height selection into migration, demonstrated by ethnic Indian adults in England being on average 6–7 cm taller than in India. However, the difference between natives and ethnic Indians in England disappears among their younger sons and daughters, although it re-appears among adolescents. We estimate that, conditional on age, gender and parental height, ethnic Indian children of age 2–4 in England are 6–8% taller than in India. Such degree of catch up in one generation is remarkable, also because in England children of ethnic Indians have much smaller birthweight than whites, by about 0.4 kg on average.  相似文献   

2.
This paper offers new evidence on human stature in south China during the second half of the 19th century and early part of the 20th. It is based on the records kept by the Government of Canada of 97,123 Chinese immigrants who were required to pay an entry tax between 1885 and 1949. While the study population included both sexes and all ages from infancy to old age, it was largely male, with most ages falling between 12 and 50. The data reveal an increase of over 4 cm in the adult heights of both sexes between 1850 and 1930. They also indicate an upward trend of over 5 cm in the heights of adolescent males. The mean heights of male immigrants fall in the lower range of those reported in other studies of stature in south China. The rising trends contrast with a pattern of stagnation and decline reported in other recent findings but are consistent with other recent evidence of increasing economic growth, real wages, and life expectancy in south China during this period. One likely cause of improved well-being is the influence of the migrants’ remittances on socioeconomic change in south China.  相似文献   

3.
Variability in musculoskeletal structure has the potential to influence locomotor function. It has been shown, for example, that sprinters have smaller Achilles tendon moment arms and longer toes than non-sprinters, and toe length has been found to correlate with toe flexor work in running humans. These findings suggest that interindividual variation in human foot structure allows for function that is adapted to various motor tasks. The purpose of this study was to test for correlations between foot anthropometry and single-joint maximal-height jumping performance. Ten male subjects performed static jumps using only their ankles for propulsion. Several anthropometric measures were taken. Bivariate correlation analyses were performed between all anthropometric variables and the average jump height for each subject. Results showed that the best jumpers had longer lateral heel lengths (r = 0.871; p = 0.001) and longer toes (r = 0.712; p = 0.021). None of the other anthropometric variables (stature, mass, lower extremity lengths) measured were found to correlate significantly with jump height. A factor analysis was performed to investigate whether some underlying feature related to body stature could explain jumping performance. Taller subjects did not necessarily jump higher. Specific variations in foot structure, unrelated to other general stature measures, were associated with performance in this single-joint jumping task.  相似文献   

4.
《Endocrine practice》2019,25(2):156-160
Objective: Despite U.S. Food & Drug Administration (FDA) approval of growth hormone (GH) for idiopathic short stature (ISS), many providers face challenges obtaining insurance coverage. We reviewed the insurance coverage experience for ISS at our hospital to identify factors predictive of approval or denial.Methods: We reviewed charts of patients who underwent GH stimulation testing from July 1, 2009, to April 30, 2017, to identify ISS patients (height <-2.25 SD, subnormal predicted adult height (PAH) and peak GH >10 ng/mL).Results: Eighty-seven patients met ISS criteria, of whom 47 (29 male/18 female) had a GH request submitted to insurance. Mean age, height, and growth velocity were 8.6 ± 2.7 years, 2.83 ± 0.4 SD, and 4.4 ± 1.7 cm/year, respectively. Mean PAH based on bone age was -2.50 ± 0.9 SD, equaling 62 inches for males and 58 inches for females. Most had private managed care insurance (74%). Overall, 17/47 (36%) received treatment approval, 7 immediately and 10 more on appeal. There were no differences in age, height SD, growth rate, insurance type, or PAH between the 17 who were approved and the 30 denied. For 21 patients who were treated, a mean increase in 0.6 SD in height was seen after 1 year.Conclusion: At our institution, GH coverage requests for ISS included very short children mostly ages 6 to 11, with heights well below -2.25 SD and poor PAH. Only 36% were approved even after appeal. This highlights the challenge in our area to secure GH treatment for a FDA-approved indication. Collaboration between pediatric endocrinologists and insurers focusing on height SD and PAH, may improve cost-effective coverage to deserving short children who meet FDA guidelines for ISS treatment.Abbreviations: FDA = Food and Drug Administration; GH = growth hormone; IGF-1 = insulin-like growth factor 1; ISS = idiopathic short stature; PAH = predicted adult height  相似文献   

5.
The physical stature of Surinamese soldiers is estimated to have increased by more than 3 cm between 1870 and 1909. In the subsequent four decades, the increase in adult male and female height amounted to 0.3–0.5 cm and 0.9–1.0 cm per decade, respectively. This increase in height continued and accelerated during the second half of the twentieth century. Height increase among African and Hindustani Surinamese males and females was similar. Height differences between African and Hindustani Surinamese were therefore fairly constant over time, at 4–5 cm. Other indicators of nutritional and health status, such as infant mortality, showed continuous improvement, whereas per capita calorie and protein availability improved in the twentieth century.  相似文献   

6.
《Endocrine practice》2020,26(11):1255-1268
ObjectiveThere are numerous reasons for short stature, including mutations in osteochondral development genes. ACAN, one such osteochondral development gene in which heterozygous mutations can cause short stature, has attracted attention from researchers in recent years. Therefore, we analyzed six cases of short stature with heterozygous ACAN mutations and performed a literature review.MethodsClinical information and blood samples from 6 probands and their family members were collected after consent forms were signed. Gene mutations in the probands were detected by whole-exome sequencing. Then, we searched the literature, performed statistical analyses, and summarized the characteristics of all reported cases.ResultsWe identified six novel mutations in ACAN: c.1411C>T, c.1817C>A, c.1762C>T, c.2266G>C, c.7469G>A, and c.1733-1G>A. In the literature, more than 200 affected individuals have been diagnosed genetically with a similar condition (height standard deviation score &lsqb;SDS] -3.14 ± 1.15). Among affected individuals receiving growth-promoting treatment, their height before and after treatment was SDS -2.92 ± 1.07 versus SDS -2.14 ± 1.23 (P<.001). As of July 1, 2019, a total of 57 heterozygous ACAN mutations causing nonsyndromic short stature had been reported, including the six novel mutations found in our study. Approximately half of these mutations can lead to protein truncation.ConclusionsThis study used clinical and genetic means to examine the relationship between the ACAN gene and short stature. To some extent, clear diagnosis is difficult, since most of these affected individuals’ characteristics are not prominent. Growth-promoting therapies may be beneficial for increasing the height of affected patients.Abbreviations: AI = aromatase inhibitor; ECM = extracellular matrix; GnRHa = gonadotropin-releasing hormone analogue; IQR = interquartile range; MIM = Mendelian Inheritance in Man; PGHD = partial growth hormone deficiency; rhGH = recombinant human growth hormone; SDS = standard deviation score; SGA = small for gestational age; SGHD = severe growth hormone deficiency  相似文献   

7.
The purpose of this study is to explore the main correlates of male height in 105 countries in Europe & overseas, Asia, North Africa and Oceania. Actual data on male height are compared with the average consumption of 28 protein sources (FAOSTAT, 1993–2009) and seven socioeconomic indicators (according to the World Bank, the CIA World Factbook and the United Nations). This comparison identified three fundamental types of diets based on rice, wheat and milk, respectively. The consumption of rice dominates in tropical Asia, where it is accompanied by very low total protein and energy intake, and one of the shortest statures in the world (∼162–168 cm). Wheat prevails in Muslim countries in North Africa and the Near East, which is where we also observe the highest plant protein consumption in the world and moderately tall statures that do not exceed 174 cm. In taller nations, the intake of protein and energy no longer fundamentally rises, but the consumption of plant proteins markedly decreases at the expense of animal proteins, especially those from dairy. Their highest consumption rates can be found in Northern and Central Europe, with the global peak of male height in the Netherlands (184 cm). In general, when only the complete data from 72 countries were considered, the consumption of protein from the five most correlated foods (r = 0.85) and the human development index (r = 0.84) are most strongly associated with tall statures. A notable finding is the low consumption of the most correlated proteins in Muslim oil superpowers and highly developed countries of East Asia, which could explain their lagging behind Europe in terms of physical stature.  相似文献   

8.
Coccidiosis in chickens causes intestinal mucosal lesions and disrupts its integrity leading to a disturbance in absorption of dietary components. The d-xylose absorption test is a sensitive tool of measuring the absorption capacity of the intestine in diseased chickens. In an experiment on broilers, the influence of different anticoccidials on the intestinal absorption capacity of the birds challenged with experimental coccidiosis was evaluated, using the d-xylose absorption test. The experiment had 5 groups of 10 Ross male broiler chickens (24-days-old) as follows: Group 1— negative control received no Eimeria oocystes, Group 2—positive control challenged with mixed Eimeria oocystes, Group 3—positive control dosed with an attenuated oral coccidiosis vaccine, Group 4—positive control dosed with 25 ppm toltrazuril in drinking water and Group 5—positive control received 66 ppm salinomycin sodium, in the diet. The d-xylose absorption test was carried out 5 days after the coccidial infection. Results showed that coccidiosis highly reduced the plasma d-xylose peak level of Group 2 when compared with Group 1 (31 mg/dl at 90 min versus 50 mg/dl at 30–60 min after the d-xylose administration, respectively). The concentration of d-xylose followed cubic (P<0.001, r2 = 0.886) and quadratic (P<0.001, r2 = 0.686) correlations with time in Group 1 and 2, respectively. Anticoccidials enhanced the uptake of d-xylose in the infected birds. The plasma d-xylose reached to its peak in Group 3, 4, and 5 (38.9, 50 and 47.0 mg/dl, respectively) at 60–90 min after the d-xylose administration and had quadratic functions with time (r2 = 0.802, 0.883 and 0.860, respectively, P<0.001). The d-xylose absorption test was a sensitive test for evaluating the influence of anticoccidials on the absorption capacity of intestinal mucosae during coccidiosis in broiler chickens.  相似文献   

9.
Current research shows strong associations between adult height and several positive outcomes such as higher cognitive skills, better earning capacity, increased chance of marriage and better health. It is therefore relevant to investigate the determinants of adult height. There is mixed evidence on the effects of undernutrition during early life on adult height. Therefore, our study aims at assessing the impact of undernutrition during gestation and at ages younger than 15 on adult height.We used data from the Longitudinal Aging Study Amsterdam. Exposure to undernutrition was determined by place of residence during the Dutch famine during World War II. Included respondents were born between 15 May 1930 and 1 November 1945 and lived in the northern part of the Netherlands during the famine period (n = 1008). Exposure data was collected using interviews and questionnaires and adult height was measured. Exposed and non-exposed respondents were classified in the age categories pregnancy- age 1 (n = 85), age 1–5 (n = 323), age 6–10 (n = 326) or puberty (age 11–15, n = 274). Linear regression analyses were used to test the associations of adult height with exposure. The robustness of the regression results was tested with sensitivity analyses.In the models adjusted for covariates (i.e., number of siblings, education level of parents, and year of birth) and stratified by gender, adult height was significantly shorter for females exposed at ages younger than 1 (−4.45 cm [−7.44–−1.47]) or at ages younger than 2 (−4.08 cm [−7.20–−0.94]). The results for males were only borderline significant for exposure under age 1 (−3.16 [−6.82–0.49]) and significant for exposure under age 2 (−4.09 cm [−7.20–−0.96]). Exposure to the Dutch famine at other ages was not consistently significantly associated with adult height.In terms of public health relevance, the study’s results further underpin the importance of supporting pregnant women and young parents exposed to undernutrition.  相似文献   

10.
Most studies analysing the influence of socioeconomic deterioration on body size focus on the impact of food shortages and diseases on the growth in early childhood. To evaluate how socioeconomic conditions influence the growth during the adolescence, we tracked the body size of 15–19 year-olds over the last sixty years covering the socialist period (1951–1990), the war (1991–1995) and the transition to capitalistic economy. This study of Zagreb, Croatia, adolescent population provides information on the secular trend in height, weight and Body Mass Index (BMI) and examines their relation with Real Gross Domestic Product. From 1951 to 2010 the girls’ height approximately increased by 6.2 cm and weight by 6.8 kg, while the boys’ height increased by 12.2 cm and weight by 17.3 kg. Prior to 1991 mean BMI in girls was higher than in boys, but from 1991 on, the interrelation between the sexes has been opposite, possibly mirroring the cultural trends that started in mid-1970s and reflecting higher sensitivity of boys to the socioeconomic changes. In conclusion, the secular trend in body size over the investigated period reflects the positive economic trends interrupted by the war. The recent increase in BMI corresponds to the country's economic recovery and indicates the “nutrition transition”.  相似文献   

11.
IntroductionBasal cell carcinoma (BCC) is the most common malignancy in the US. Body mass index (BMI) and height have been associated with a variety of cancer types, yet the evidence regarding BCC is limited. Therefore, we evaluated BMI and height in relation to early-onset BCC (under age 40) and explored the potential role of ultraviolet (UV) radiation exposure and estrogen-related exposures in the BMI-BCC relationship.MethodsBCC cases (n = 377) were identified through a central dermatopathology facility in Connecticut. Control subjects (n = 389) with benign skin conditions were randomly sampled from the same database and frequency matched to cases on age (median = 36, interquartile range 33–39), gender, and biopsy site. Participants reported weight (usual adult and at age 18), adult height, sociodemographic, phenotypic, and medical characteristics, and prior UV exposures. We calculated multivariate odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression models.ResultsAdult BMI was inversely associated with early-onset BCC (obese vs. normal OR = 0.43, 95% CI = 0.26–0.71). A similar inverse association was present for BMI at age 18 (OR = 0.54, 95% CI = 0.34–0.85). Excluding UV exposures from the BMI models and including estrogen-related exposures among women only did not alter the association between BMI and BCC, indicating limited mediation or confounding. We did not observe an association between adult height and BCC (OR per cm = 1.00, 95% CI = 0.98–1.02).ConclusionsWe found a significant inverse association between BMI and early-onset BCC, but no association between height and BCC. This association was not explained by UV exposures or estrogen-related exposures in women.  相似文献   

12.
Plant biomass is a key parameter for estimating terrestrial ecosystem carbon (C) stocks, which varies greatly as a result of specific environmental conditions. Here, we tested environmental driving factors affecting plant biomass in natural grassland in the Loess Plateau, China. We found that above-ground biomass (AGB) and below-ground biomass (BGB) had a similar change trend in the order of Stipa bungeana > Leymus secalinus > Artemisia sacrorum > Artemisia scoparia, whereas shoot ratio (R/S) displayed an opposite change trend. There was a significantly positive linear relationship between the AGB and BGB, regardless of plant species (p < 0.05). Furthermore, more than 50% of the AGB were found in 20–50 cm of plant height in Compositae plants (A. sacrorum, A. scoparia), whereas over 60% of the AGB were found in 20–80 cm of plant height in Gramineae plants (S. bungeana, L. secalinus). For each plant species, more than 75% of the BGB was distributed in 0–10 cm soil depth, and 20% was distributed in 10–20 cm soil depth, while less than 5% was distributed in 20–40 cm soil depth. Further, AGB and BGB were highly affected by environmental driving factors (soil properties, plant traits, topographic properties), which were identified by the structural equation model (SEM) and the generalized additive models (GAMs). In addition, AGB was directly affected by plant traits, and BGB was directly affected by soil properties, and soil properties associated with plant traits that affected AGB and BGB through interactive effects were 9.12% and 3.59%, respectively. However, topographic properties had a weak influence on ABG and BGB (as revealed by the lowest total pathway effect). Besides, soil organic carbon (SOC), soil microbial biomass carbon (MBC), and plant height had a higher relative contribution to AGB and BGB. Our results indicate that environmental driving factors affect plant biomass in natural grassland in the Loess Plateau.  相似文献   

13.
A 2-year field experiment was performed with lachenalia (‘Namakwa’, ‘Ronina,’ ‘Rosabeth’ and ‘Rupert’) to study the effects of planting density on leaf formation, inflorescence quality and bulb production. Bulbs 6.0 cm in circumference were planted at a spacing of 2.0 × 5.0 cm, 3.0 × 7.0 cm and 5.0 × 10.0 cm, and cultivated in the open air in Polish conditions in 2009 and 2010. The spacing affected the number of leaves only in lachenalia ‘Namakwa’ in 2010. In the other cases, the bulbs formed 2–3 leaves. Plant height increased with the high-density treatment, but flower yield and the total time to the beginning of flowering were independent of planting density. The cultivars proved to differ in terms of the time of blooming: ‘Namakwa’ and ‘Ronina’ flowered earlier (after 63–73 days) than ‘Rosabeth’ and ‘Rupert’ (after 82–90 days). Plant arrangement had little effect on inflorescence length and the number of florets. Irrespective of the spacing, lachenalia ‘Rupert’ seemed to be the most floriferous — one bulb produced even 30 flowers. Lower planting density influenced advantageously the quality of bulbs (circumference and weight), without affecting their quantity (number of bulbs from one plant).  相似文献   

14.
This paper analyze the association between height and chronic diseases in Portugal and the extent to which this relationship is mediated by education. The sample upon which the analysis is based comprised those participants in the 2005/2006 Portuguese National Health Interview Survey (n = 28,433) aged 25–79. Logistic regressions measured the association of height with ten chronic diseases, adjusting for age, lifestyle, education, and other socioeconomic factors. Among women, an additional centimeter in stature significantly decreased the prevalence of asthma, chronic pain, and acute cardiac disease, by 0.057, 0.221, and 0.033 percentage points, respectively. Also, mental disorders were significantly less prevalent in the last quartile of height. Among men, an additional centimeter in height was associated with a 0.074 lower prevalence of asthma, and men in the last quartile of height were significantly less at risk of acute cardiovascular disease. There was no significant association between height and the risk of diabetes, high blood pressure, cancer, and pulmonary diseases. As for the impact of education, women with a tertiary level were on average 5.3 cm taller than those with no schooling; among men, the difference was almost 9 cm. Adjusting for education reduced the height-related excess risk of ill health by 36% on average among men, and by 7% among women. The analysis indicates that there is a significant association of height with several chronic conditions, and that education plays a mediating role in the height–health connection. By emphasizing the role of height and education as determinants of chronic conditions, this paper also highlights the role of conditions related to childhood health and socioeconomic background.  相似文献   

15.
We examine the evolution of adult female heights in twelve Latin American countries during the second half of the twentieth century based on demographic health surveys and related surveys compiled from national and international organizations. Only countries with more than one survey were included, allowing us to cross-examine surveys and correct for biases. We first show that average height varies significantly according to location, from 148.3 cm in Guatemala to 158.8 cm in Haiti. The evolution of heights over these decades behaves like indicators of human development, showing a steady increase of 2.6 cm from the 1950s to the 1990s. Such gains compare favorably to other developing regions of the world, but not so much with recently developed countries. Height gains were not evenly distributed in the region, however. Countries that achieved higher levels of income, such as Brazil, Chile, Colombia and Mexico, gained on average 0.9 cm per decade, while countries with shrinking economies, such as Haiti and Guatemala, only gained 0.25 cm per decade.  相似文献   

16.
《Endocrine practice》2020,26(9):997-1002
Objective: Patients with 21-hydroxylase deficiency (21OHD) typically suffer from short stature due to early exposure to adrenal-derived androgen. The aim of this study was to investigate whether adding aromatase inhibitor (AI) to gonadotropin-releasing hormone (GnRH) analogue (GnRHa) and recombinant human growth hormone (rhGH) therapy would increase the height of patients with 21OHD.Methods: This retrospective study included 15 patients with 21OHD. The AI/GnRHa/rhGH group consisted of 9 patients, who were treated with AI for at least 12 months in addition to GnRHa/rhGH therapy. The other 6 patients, who received GnRHa/rhGH therapy only, were defined as the GnRHa/rhGH group.Results: Patients were 6.3 ± 1.7 years old, and 7/15 of patients were male. Among them, 12 patients exhibited simple virilization type, and 3 patients were salt-wasting type. In the AI/GnRHa/rhGH group, patients were 6.6 ± 2.0 years old when AI therapy was initiated. Their bone age was 5.9 ± 2.2 years ahead of their chronological age. They received the AI letrizole for an average of 25.1 months (range, 12 to 37 months). In the GnRHa/rhGH group, the patients were 5.9 ± 0.9 years old when they started GnRHa/rhGH therapy, and their bone age was 6.2 ± 1.7 years ahead of their chronological age. Patients received GnRHa/rhGH therapy for an average of 24.5 months (range, 12 to 41 months). The predicted final height increased from 145.9 ± 7.9 to 158.0 ± 8.4 cm in the AI/GnRHa/rhGH group (P = .001, compared with the baseline) and from 141.7 ± 2.7 to 150.7 ± 4.7 cm in the GnRHa/rhGH group (P = .001, compared with the baseline). Bone age progression was 0.15 ± 0.05 per year versus 0.44 ± 0.13 per year in the two groups, respectively (P = .032).Conclusion: Addition of letrizole to GnRHa/rhGH therapy significantly delays bone maturation and may increase the final height.  相似文献   

17.
While a growing literature has documented a link between neighborhood context and health outcomes, little is known about the relationship between neighborhood characteristics and height. Using individual data from the 1999-2004 U.S. National Health and Nutrition Examination Survey merged with tract-level data from the U.S. Census, we investigate several neighborhood characteristics, including neighborhood socioeconomic status (NSES), education index of concentration at the extremes (ICE), and population density, as potential predictors of height. Employing a series of two-level random intercept models, we find a one standard deviation increase in NSES to be associated with a 0.6–1.4 cm height advantage for white and foreign-born Mexican-American females and for U.S. born Mexican-American males, net of individual-level controls. Similarly, a 10 point increase in neighborhood education ICE was associated with 0.23–0.32 cm greater height for white and foreign-born Mexican-American females and U.S. born Mexican-American males. Population density was nominally negatively associated with height for foreign-born Mexican-American females. Our findings reveal that lower physical stature for some ethnic and gender groups is clustered within neighborhoods of low SES and education, suggesting that contextual factors may play a role in influencing height above individual-level attributes.  相似文献   

18.
Quantifying the association of plant functional traits to environmental gradients is a promising approach for understanding and projecting community responses to land use and climatic changes. Although habitat fragmentation and climate are expected to affect plant communities interactively, there is a lack of empirical studies addressing trait associations to fragmentation in different climatic regimes.In this study, we analyse data on the key functional traits: specific leaf area (SLA), plant height, seed mass and seed number. First, we assess the evidence for the community assembly mechanisms habitat filtering and competition at different spatial scales, using several null-models and a comprehensive set of community-level trait convergence and divergence indices. Second, we analyse the association of community-mean traits with patch area and connectivity along a south–north productivity gradient.We found clear evidence for trait convergence due to habitat filtering. In contrast, the evidence for trait divergence due to competition fundamentally depended on the null-model used. When the null-model controlled for habitat filtering, there was only evidence for trait divergence at the smallest sampling scale (0.25 m × 0.25 m). All traits varied significantly along the S–N productivity gradient. While plant height and SLA were consistently associated with fragmentation, the association of seed mass and seed number with fragmentation changed along the S–N gradient.Our findings indicate trait convergence due to drought stress in the arid sites and due to higher productivity in the mesic sites. The association of plant traits to fragmentation is likely driven by increased colonization ability in small and/or isolated patches (plant height, seed number) or increased persistence ability in isolated patches (seed mass).Our study provides the first empirical test of trait associations with fragmentation along a productivity gradient. We conclude that it is crucial to study the interactive effects of different ecological drivers on plant functional traits.  相似文献   

19.
《Palaeoworld》2014,23(1):90-104
The temporal and spatial distributions of the radiolarian species Spongodiscus biconcavus Haeckel are investigated to understand the paleoceanographic evolution of the Bering Sea region during the last 4.3 Myr based on extensive study of samples collected at Site U1340 during the IODP Expedition 323. The biostratigraphic resolution for the region is also improved by multidisciplinary studies of radiolarians, diatoms, dinoflagellates, ebridians, and silicoflagellates. The results demonstrate that the abundance variation of S. biconcavus during the last 4.3 Myr is closely related to global climate changes, and the species can be used as a warm water and climate proxy in the Bering Sea. Based on the downhole profiles of S. biconcavus and other parameters, we conclude that the southern Bering Sea was associated with a warm water mass prior to 3.147 Ma but it gradually cooled thereafter. From 2.793 Ma to 0.889 Ma, a cold water mass and sea-ice predominated in the Bering Sea, in response to the early Northern Hemisphere glaciation (NHG). Furthermore, the climate suddenly became much cooler post 0.889 Ma. Nevertheless, a reversal of this cooling trend occurred after the Mid-Pleistocene Climatic Transition (∼1.2 Ma), marked by reoccurrence of warm water and reduced sea-ice in the Bering Sea until the final retreat of warm water mass from the Bering Sea after 0.239 Ma. These processes are correlated with biogeographic expansion and retreat of warm water planktonic species.  相似文献   

20.
Background: Acute lymphoblastic leukemia (ALL) is a complex disease with genetic background. The genetic association studies (GAS) that investigated the association between ALL and the MTHFR C677T and A1298C gene variants have produced contradictory or inconclusive results. Materials and methods: In order to decrease the uncertainty of estimated genetic risk effects, a meticulous meta-analysis of published GAS related the variants in the MTFHR gene with susceptibility to ALL was conducted. The risk effects were estimated based on the odds ratio (OR) of the allele contrast and the generalized odds ratio (ORG). Cumulative and recursive cumulative meta-analyses were also performed.ResultsThe analysis showed marginal significant association for the C677T variant, overall [OR = 0.91 (0.82–1.00) and ORG = 0.89 (0.79–1.01)], and in Whites [OR = 0.88 (0.77–0.99) and ORG = 0.85 (0.73–0.99)]. The A1298C variant produced non-significant results. For both variants, the cumulative meta-analysis did not show a trend of association as evidence accumulates and the recursive cumulative meta-analysis indicated lack of sufficient evidence for denying or claiming an association. Conclusion: The current evidence is not sufficient to draw definite conclusions regarding the association of MTHFR variants and development of ALL.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号