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1.
Thalassemia is one of the most common single gene diseases worldwide. Populations in southern China and Taiwan have high prevalence rates of alpha- and beta-thalassemias. This review summarizes the current status of molecular studies, carrier screening, and prenatal diagnosis of thalassemia in Chinese. There are three genotypes of alpha-thalassemia 1 and at least six of alpha-thalassemia 2 in Chinese. For alpha-thalassemia 1, the South-East Asian deletion is the most common, followed by the Thai then Philippino deletions. For alpha-thalassemia 2, the rightward deletion is the most common, followed by the leftward deletion, and the nondeletional defects Hb Constant Spring and Hb Quong Sze. Twenty-eight different beta-thalassemia mutations have been reported. Four mutations, IVS-II-654 (C-->T), codons 41/42 frameshift (-TCTT), and nonsense codons 17 (A-->T) and -28 (A-->G), account for more than 90% of mutant alleles. For detection of alpha-thalassemia, polymerase chain reaction-related techniques are mainly used. Southern blot hybridization is still useful, especially for prenatal diagnosis. For detection of beta-thalassemia mutations, analysis of amplification-created restriction sites and reverse dot blot hybridization have been extensively used. In Taiwan, a national screening program incorporating hematological and molecular biological methods for thalassemia detection in pregnant women has been in progress for 5 years. Prenatal diagnosis has been performed in more than 1,800 pregnancies, including 1,500 cases at risk for homozygous alpha-thalassemia 1 and 300 for beta-thalassemia major, resulting in early prenatal diagnosis and termination of pregnancies affected with homozygous alpha-thalassemia 1 and an approximately 70% decrease in the number of newborns affected with beta-thalassemia major. In mainland China, only one large-scale screening program is in place. Characterization of undefined alleles, a higher awareness of the disease among physicians and the general public, and improvement of the service network will be important for early prenatal diagnosis and prevention of the disease in the future. 相似文献
2.
S Fucharoen P Winichagoon R Wisedpanichkij B Sae-Ngow R Sriphanich W Oncoung W Muangsapaya J Chowthaworn S Kanokpongsakdi A Bunyaratvej A Piankijagum C Dewaele 《Canadian Metallurgical Quarterly》1998,44(4):740-748
The conventional approach to qualitative and quantitative analyses of hemoglobin (Hb) molecules for the diagnoses of hemoglobinopathies requires a combination of tests. We used an automated HPLC (VARIANT) system to study alpha-thalassemia and beta-thalassemia syndromes in Thailand. The beta-thalassemia short program is applicable to the diagnosis of alpha-thalassemia and beta-thalassemia disorders, including Hb H, EA Bart's disease, and EF Bart's disease, in adults, newborns, and fetuses. The system cannot quantify accurately certain Hb molecules, such as Hb H and Hb Bart's. The alpha-thalassemia short program was therefore developed and used to quantify Hb Bart's to detect alpha-thalassemia genotypes in cord blood. This automated HPLC system is an alternative approach to the diagnosis of complicated thalassemia syndromes in Thailand and Southeast Asia. 相似文献
3.
KH Mak A Lubenko P Greenwell D Voak KF Yan J Poole 《Canadian Metallurgical Quarterly》1996,36(11-12):994-999
BACKGROUND: The occasional presence of H-deficient red cells among both referred and donor blood samples prompted the mass screening of donated blood in Hong Kong for H-deficient phenotypes; 96 percent of the donors tested are Chinese from the southern province of Kwongtung. STUDY DESIGN AND METHODS: Donor blood was screened for H-deficient red cells with the use of Ulex europaeus. Lewis phenotyping was carried out on all H-deficient individuals, and saliva testing was performed on most such individuals. The thermal amplitude and potency of their anti-H and anti-HI in the serum were also estimated. RESULTS: Between 1984 and 1993, 28 H-deficient blood donors were identified; 16 H-deficient patient samples were also identified, and family studies revealed an additional 7 H-deficient subjects. The H-deficient red cells did not react with anti-H lectin, the levels of ABH substances in saliva were normal or near-normal, normal levels of A or B transferase were found in plasma, minute quantities of A or B (in persons who were genetically group A or B) were detected on the red cells, and anti-H or anti-HI was detected in the serum (about 66.7% of which reacted at 37 degrees C). Atypical anti-A or anti-B was demonstrated in 81.8 percent of the cases. CONCLUSION: The H-deficient phenotype among the Hong Kong Chinese seems to represent a homogeneous group. Despite the presence of normal quantities of ABH substance in the saliva, anti-H or anti-HI that was active at 37 degrees C was detected in most cases. The incidence of the H-deficient phenotype was 1 in 15,620. 相似文献
4.
OBJECTIVES: To analyze the molecular abnormalities of beta-thalassemia intermedia and contribute to the knowledge of the molecular diagnosis and prenatal diagnosis of this disorder. METHODS: In 14 patients with beta-thalassemia intermedia, we analyzed the hematologies, alpha, beta and gamma globin gene organization and structure as well as globin gene biosynthesis by Southern blot hybridization, multiplex allale specific PCR (MAS-PCR), DNA sequencing and micro-globin chain biosynthetic assay. Moreover, alpha globin gene organization was studied in 250 cord blood specimens. RESULTS: Of the 14 patients, 4 were found to be beta-thalassemia heterozygotes combined with rightward cross-over or/and leftward cross-over triplicated haplotype of alpha-globin gene loci (alpha alpha alpha anti3.7 or/and alpha alpha alpha anti4.2), 3 were compound heterozygotes for beta-thalassemia combined with alpha-thalassemia 1 or 2, one was identified to be a compound heterozygote for beta-thalassemia combined with G gamma promotor-158 (C-->T) mutation. The data of the alpha globin gene organization in 250 cord blood specimens showed that 8 of the 500 tested chromosomes (1.6%) were abnormal: 3 were alpha alpha alpha anti3.7, 4 were alpha -3.7, and one was --SEA. CONCLUSION: In addition to beta-thalassemia homozygote or compound heterozygotes with alpha thalassemia, the conjunctive abnormalities of beta-thalassemia heterozygote with alpha-globin gene triplication was another major cause of beta-thalassemia intermedia. 相似文献
5.
The characteristics of familiar atypical microcytosis studied during one year were evaluated. Out of 149 patients with microcytosis in whom iron deficiency was ruled out, a heterogenous beta-thalassemia was diagnosed in 72 cases, a heterozygous delta beta-thalassemia in 16 cases and a hemoglobinopathy in 3 cases. The microcytosis was related to an inflammatory anemia in 12 cases and to an hemopathy in 9 cases. An atypical microcytosis was detected in 37 patients. A familiar and molecular analysis was carried out to detect alpha-thalassemia in cases with atypical microcytosis. It was possible to complete the familiar and molecular analysis in 35 out of 37 cases, and an alpha-thalassemia was observed in 31 patients. Most cases proved to be heterozygous or homozygous-alpha 3.7-thalassemia. No patient with heterozygous alpha zero-thalassemia was found. Most cases of familiar atypical microcytosis in our country are due to -alpha 3.7-thalassemia. Bearing these findings in mind, this analysis should only be used in situations where a problem of prenatal diagnosis is present. Moreover, systematic molecular analysis of familiar atypical microcytosis could be justified if the MCV is lower than 75 fl. 相似文献
6.
Prevalence of thalassemias and/or hemoglobinopathies, particularly hemoglobin E, and cholangiocarcinoma were found more prominently in the lower part of the Northeast of Thailand as compared with the upper part of this region or any other area of the country. The aim of this study was to evaluate if there was coincident distribution or some relationship. Hemoglobin typing by the cellulose acetate method was performed in 111 cases of cholangiocarcinoma, mainly diagnosed by ultrasonography, compared with 146 normal controls. It was found that hemoglobin E trait and beta-thalassemia trait were significantly higher in the former group. 相似文献
7.
R Hutagalung P Wilairatana S Looareesuwan GM Brittenham M Aikawa VR Gordeuk 《Canadian Metallurgical Quarterly》1999,179(1):283-286
To determine if hemoglobin E trait influences the course of acute malaria, adults hospitalized for the treatment of symptomatic infection with Plasmodium falciparum were studied retrospectively. Forty-two patients with hemoglobin E trait were compared with 175 reference subjects who did not have hemoglobin E, beta-thalassemia, glucose-6-phosphate dehydrogenase deficiency, or alpha-thalassemia. One patient (2.4%) with hemoglobin E trait had a severe complication of malaria by World Health Organization criteria (cerebral malaria), while 32 subjects in the reference group (18.3%) had one or more severe complications: cerebral malaria (n=18), hyperparasitemia (n=16), renal failure (n=10), and severe anemia (n=1) (P=.044 after adjustment for ethnic categories). The estimated odds of severe complications in the reference subjects were 6.9 times the odds in patients with hemoglobin E trait (95% confidence interval, 1.2-146. 4). These results suggest that hemoglobin E trait may ameliorate the course of acute falciparum malaria. 相似文献
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9.
We have characterized the mutations in 1050 carriers of the beta-thalassemia gene and analyzed their regional distribution in India. The majority of beta-thalassemia carriers were migrants from Pakistan and their pattern of mutations differed from the rest. The frequency of the 619-bp deletion was 33.3% among the migrants from Pakistan, 8-17% in the northern states, and less than 5% in the other states. Among non-migrant subjects, the predominant mutation was IVS-I-5 (G-->C), varying from 85% in the southern states and 66-70% in the eastern states to 47-60% in the northern states. The mutation IVS-I-1 (G-->T) was observed at high frequency among the migrants from Pakistan (26.2%), but with very low/zero frequency in the other states. Mutations at codons 8/9 (+G) and codons 41/42 (-CTTT) were distributed in all regions of India with a frequency varying from 3% to 15%. Only eight of 12 published rare mutations were observed in subjects from different parts of India. Mutations of codon 5 (-CT) and codons 47/48 (+ATCT) were found exclusively in migrants from Pakistan, and mutation -88 (C-->T) was detected only in subjects from Punjab, Haryana, and Uttar Pradesh. Using the amplification refractory mutation system technique, mutations were successfully identified in 98.2% of subjects. Overall, 91.8% of the subjects had one of the five commonest mutations [IVS-I-5 (G-->C), 34.1%; 619-bp deletion, 21.0%; IVS-I-1 (G-->T) 15.8%; codons 8/9 (+G), 12.1%, and codons 41/42 (-CTTT), 8.7%], 5.9% of the subjects had a less common mutation, while 1.8% of the carriers remained uncharacterized. The application of this knowledge has helped to successfully establish a program of genetic counselling and prenatal diagnosis of beta-thalassemia in order to reduce the burden of this disease in India. 相似文献
10.
Education is a systematic teaching-learning process involving four main components (teachers, students, knowledge, and the environment) and three main subprocesses (teaching, learning, and evaluation). Throughout the education process, students’ learning is considered as the core subprocess, though various interactions are involved among the variables in the components. The surface-achieving learning approach (achieving motive and surface strategy) is not generally recommended by educational psychologists, but it is the most popular learning approach used by construction engineering students in Hong Kong. In order to investigate the reasons for this phenomenon, a structural surface-achieving learning model is established that includes key learning factors. In this paper, teaching approach, learning approach (achieving motive and surface strategy), year of study, gender, performance, and satisfaction are all considered as major elements of the teaching-learning process. Using the LISREL program, three optimized structural equation models were established separately for the three teaching approaches (transferring, shaping, and traveling). The study confirmed a partial causal relationship among the hypothetical variables and revealed six interesting points: (1) shaping is an exogenous variable that has the least effect on the surface-achieving learning approach among the three teaching approaches; (2) the traveling teaching approach, like the transferring and shaping teaching approaches, causes students to adopt the surface strategy in the learning process; (3) good performance can be obtained even though the surface strategy is adopted by construction students in Hong Kong; (4) students’ performance is a factor encouraging or discouraging educators to use the traveling teaching approach in construction education; (5) satisfaction is an essential variable that induces students to learn with an achieving motive; and (6) female construction students often perform better than their male counterparts. 相似文献
11.
BACKGROUND: Screens for anemia are among the most commonly done laboratory tests in children. The red cell distribution width (RDW) has been proposed as a diagnostic aid in the evaluation of pediatric anemias, but no prospective studies have been published describing its use. METHODS: A screening hematocrit determination done at the 12-month well-baby examination in 970 healthy infants yielded 62 low values (< 33%), 31 of which were confirmed by heel stick complete blood count (CBC). After a 1-month trial of iron therapy, those with a rise in hemoglobin of at least 1 g/dL were considered to have iron-deficiency anemia. Nonresponders, after review of clinical and laboratory data (CBC, lead screen, and sickle screen), had hemoglobin electrophoresis if indicated. RESULTS: Abnormalities detected were iron deficiency, alpha-thalassemia, and hemoglobins SC and AS. These conditions were detected in 9 of 11 infants with abnormal RDW and none of 9 with normal RDW. CONCLUSIONS: The RDW alone appears to be predictive of identifiable causes of anemia when used in screening 12-month-old babies who are otherwise healthy. 相似文献
12.
In subtropical coastal waters around Hong Kong, algal blooms and red tides have been frequently observed over the past two decades. In particular, in March–April 1998, a massive red tide invaded the northeastern and southern coastal waters of Hong Kong. The devastating red tide resulted in the worst fish kill in Hong Kong’s history, the most significant impacts being at the Lo Tik Wan and Sok Kwu Wan fish culture zones on Lamma Island. This work reports the first scientific investigation of the cause of this massive red tide. A calibrated three-dimensional (3D) hydrodynamic model for the Pearl River Estuary, Delft3D, is applied to study the advective transport of red tides. Based on the tidal boundary conditions and the measured wind data for a typical spring season, the 3D flow field is computed and extensive surface drogue tracking performed for releases in different parts of the coastal waters and for different tidal and wind conditions. The results show that a bloom initiated in Mirs Bay (Nan Au or Tap Mun) in the northeastern water would likely be transported to the southern coastal waters under the combined action of tidal current and wind. The computed bloom tracking patterns are generally supported by observations and are consistent with the temporal and spatial patterns of individual fish kill events in the 1998 red tide. We conclude that the major cause of the bloom being transported into the southern waters and East Lamma Channel (and causing the massive fish kill) is the generally strong wind in March–April 1998 and the change in wind direction in early April under almost diurnal tidal conditions. Further, it is most probable that the red tide originated in Mirs Bay rather than from outside Hong Kong. The findings provide a firm basis for environmental and fisheries management. 相似文献
13.
XW Zheng JP Zhang CQ Tian HH Cheng XZ Yang S Duan DQ Li 《Canadian Metallurgical Quarterly》1993,6(4):348-351
Among Hong Kong Chinese blood donors, 99.71 percent were found to be D+. Of these, 55.02 percent were of the phenotype CCDee. The Du phenotype was found to be present in 0.016 percent. Among the 0.27 percent who were apparently D-, 0.079 percent were of the Del phenotype, while the remaining 0.19 percent were "true D-," as defined by a nonreactive eluate obtained by an adsorption and elution procedure using anti-D. The ccdee phenotype constitutes 56.77 percent of the "apparent D-" and 80.24 percent of the true D-. Data show that anti-D rarely occurs in Hong Kong Chinese, and it is postulated that this could be due to the presence of a very weak form of the D antigen among many of those who appear to be D-. 相似文献
14.
van den Berg Matthijs; Timmermans Danielle R. M.; Knol Dirk L.; van Eijk Jacques Th. M.; de Smit Denhard J.; van Vugt John M. G.; van der Wal Gerrit 《Canadian Metallurgical Quarterly》2008,27(4):430
Objective: This study is aimed at enhancing understanding prenatal screening decision making through testing a hypothesized decision model based on decision theory and health behavior theory. Design: We obtained questionnaires from 1,666 pregnant women who were offered prenatal screening for Down's syndrome. Path analysis (using LISREL) resulted in a final model with reasonable model fit, which was verified by split-sample cross-validation. Main outcome measures: These included perceived probability, perceived severity, attitude toward termination, response efficacy, attitude toward prenatal screening, subjective norm, child-related anxiety, and intention to undergo prenatal screening. Results: Attitude toward termination of pregnancy, perceived test efficacy, and subjective norm regarding the desirability of having prenatal screening determined a woman's attitude toward having a prenatal test. Anxiety was influenced by perceived risk and perceived severity of having a child with Down's syndrome, and by subjective norm, but this appeared to be a weak predictor of intention to test. Pregnant women with a positive attitude toward prenatal screening, and who perceived a subjective norm in favor of undergoing prenatal screening, showed a greater intention to have prenatal screening done. Conclusion: These findings suggest that more attention should be paid toward the values and social context of pregnant women during the counseling process. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
15.
Albert P. C. Chan Patrick T. I. Lam Daniel W. M. Chan Esther Cheung Yongjian Ke 《Canadian Metallurgical Quarterly》2009,135(11):1115-1124
The private sector has long been involved in delivering public sector projects, whether its role has been as a partner or just as a contractor for the government. Over recent years the interest in adopting public private partnerships (PPPs) has increased internationally. Many research studies have presented positive reasons for the governments and the private sector to welcome this form of procurement, rather than continue adopting the traditional options. This paper aims to explore and compare the key drivers for adopting PPP in China and the Hong Kong Special Administrative Region (referred to as Hong Kong from here onwards). An empirical questionnaire survey was conducted in both of these administrative systems and survey respondents were invited to rate their perceptions on the importance of 15 different drivers identified. Eighty-seven completed survey questionnaires were returned for analysis. The findings indicated that respondents from China rated economy-related drivers higher, whereas Hong Kong respondents tended to rate efficiency-related drivers higher. China’s demand for more public infrastructure and services has imposed great pressure on the government’s budget, and therefore economic drivers were rated higher. On the other hand, with adequate financial reserve in hand and budget surplus over recent years, Hong Kong has tended to prefer paying for projects upfront, and hence efficiency was regarded more significantly. Among the 15 drivers, both of the respondents from China and Hong Kong selected, “provide an integrated solution (for public infrastructure/services)” and “solve the problem of public sector budget restraint” to be within the top three drivers. Despite the general agreement on the ranking pattern, the results of independent two-sample t-test showed that China and Hong Kong shared very different views on the driver “reduce the total project cost.” This driver was ranked rather high by the mainland Chinese respondents, but much lower by the Hong Kong respondents. This finding can be construed that economic drivers are in general rated higher in China as compared to that in Hong Kong. 相似文献
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17.
Learning is a process of acquiring knowledge, and students may adopt different learning approaches to achieving their learning goals. While educationalists can draw up what they believe is a good construction curriculum for students, students’ learning would depend on their own learning approaches and attitudes. Acknowledging a lack of research on the learning attitudes of construction students, a matrix framework of learning approaches (MFLA) based on the relationships between three learning motives and three learning strategies is proposed in this paper. The MFLA enabled a major empirical survey to be carried out in Hong Kong to examine the learning characteristics of construction students. A questionnaire based on Biggs’s study process questionnaire was distributed to five groups of construction-related students in three universities in Hong Kong. The results of the survey indicate that seven of the nine hypothetical learning approaches exist in construction education in Hong Kong. The assortment of learning approaches used varied across the five student groups. As a result, different teaching and learning factors should be adopted by educators of construction students to meet the distinctive characteristics of students in various universities. 相似文献
18.
A rapid and simple procedure measuring the rate of hemolysis of 50% of erytrocytes suspended in a standardized glycerol mixture (GLT/50) has been compared with the erytrocyte osmotic fragility to NaCl 0.375% concentration, carried out according to Parpat's method modified, in order to estimate the respective behaviour in the screening of beta-thalassemia trait. The GLT/50 is provided with more selectivity especially between beta-thalassemia trait carriers and other subjects with iron deficiency anemia. 相似文献
19.
The health-related behaviors of a random sample (n = 92) of Hong Kong nurses were assessed by a questionnaire written either in English or in English and Chinese. Hong Kong nurses reported negligible smoking or alcohol use, low levels of breast self-examination, cervical screening behaviour and regular exercising, seat belt use and driving within the speed limit. The sample reported high levels of making efforts to avoid foods high in cholesterol, eating foods high in fibre and eating fruit daily. Dental hygiene was reported to be high. Just over half the sample reported sleeping 7-8 hours each night and eating breakfast daily. Most nurses reported maintaining their body weight at a healthy level and eating snacks between meals. The English language version of the questionnaire produced a slightly better response rate than the bilingual questionnaire. The results are discussed with reference to previous studies of females' health-related behaviours in Hong Kong and elsewhere. The implications for Hong Kong nurses' role in health promotion is discussed. 相似文献
20.
The prevalence of pyruvate kinase (PK) deficiency among the Chinese population has not been established. Fung et al. (Arch Dis Child 44:373-376, 1969) and Wu et al. (Am J Hematol 20:139-144, 1985) indicate 3.4% and 2.1% PK deficiency prevalence rates, respectively, the higher figure based on Beutler's screening test [3] without confirmatory testing. Neither figure is consistent with the occurrence of hemolytic anemia from this cause in the experiences of hematologists in Hong Kong. Using the standard quantitative assay, we measured PK activity in blood samples from 1,100 local Chinese people. The assay was automated on a centrifugal analyser, and the results were expressed in IU per gram of hemoglobin (IU/g Hb). Blood samples from 497 healthy male adults were measured, and PK activity was found to have a range of 15.2 +/- 5.2 (mean +/- 2 SD). A total of 100 cord blood samples were also measured, and the reference interval for this subgroup was 17.7 +/- 4.8. Additionally, samples from 503 anaemic patients were measured, and all were found to have values above the lower limit of the reference interval. The prevalence of PK deficiency among the Hong Kong Chinese population determined by this study was < 0.1%. 相似文献