ICRP1990年建议书

这是ICRP总委员会RH. Clarke博士根据即将出版的新建议书所学的概要,比较系统的扼要,抓住了重点。为此将全文译出,以飨读者。——译者注。     

Thiopurine methyltransferase alleles in British and Ghanaian populations

Thiopurine methyltransferase (TPMT) catalyses the S-methylation of thiopurine drugs such as 6-mercapto-purine, 6-thioguanine and azathioprine. TPMT activity is inherited as an autosomal co-dominant trait, and several mutations in the TPMT gene have been identified which correlate with a low activity phenotype. Although ethnic differences in TPMT activity have been described, population frequency analysis of TPMT alleles has not been well defined in different ethnic groups. The frequency of four allelic variants of the TPMT gene, TPMT*2, TPMT*3A, TPMT*3B and TPMT*3C were compared in British Caucasian (n = 199) and Ghanaian (n = 217) populations using PCR-RFLP and allele- specific PCR-based assays. TPMT*3C was found in 14.8% of Ghanaians (31 heterozygotes, one homozygote). The TPMT*2, TPMT*3A and TPMT*3B alleles were not detected in any of the Ghanaian samples analysed. In contrast, 10.1% of British subjects had variant alleles, consisting of TPMT*2 (n = 2), TPMT*3A (n = 17) and TPMT*3C (n = 1) alleles. The frequencies of mutant alleles in this study were 5.3 and 7.6% in British Caucasians and Ghanaians, respectively. Among Ghanaian tribes, Ewe subjects had a lower frequency of mutant alleles (5.9%) than Ga (13.2%) or Fanti (11.6%), although this did not reach statistical significance. This study provides the first analysis of TPMT mutant allele frequency in an African population and indicates that, unlike Caucasians, TPMT*3C is the most common allele in African subjects.      

Past and current smoking in relation to body fat distribution in older men and women.

BACKGROUND: Smoking is reported to be positively related to abdominal fat in young and middle-aged persons; however, it is unclear whether this relationship exists in elderly persons. Behavioral influence on fat distribution is of importance because of the accumulation of abdominal fat with age and its associated health risks. METHODS: The relationship was investigated in a population-based sample of 1,178 men and 1,163 women aged 55-85 years, representative of the Dutch older population in 1992-1993. Waist and hip circumference and their ratio were used as indices of fat distribution. Past and current smoking habits were obtained by questionnaire. RESULTS: Smoking was associated with waist/hip-ratio (WHR) in men, with current smokers having the highest WHR and never smokers the lowest. A dose-response relationship between the daily number of cigarettes smoked and WHR was observed in men. These associations remained significant after adjustment for confounding due to age, education, body mass index, health status, alcohol intake, and sports activity. The dose-response relationship did not change after additional adjustment for duration of smoking. Among former male smokers, recent quitters had a higher WHR compared to long-term quitters. Additional analysis showed that smoking was more strongly associated with waist than with hip circumference. In women the relationship between smoking and fat distribution was not clear. CONCLUSIONS: Past and current smoking habits are positively associated with abdominal fat in older men, but not in older women.     

Temporomandibular joint clicking with nonreducing anterior displacement of the meniscus

Patients who have temporomandibular joint (TMJ) clicking and pain are assumed to have an anterior displacement of the meniscus with reduction on opening of the jaw. On the basis of this assumption, these patients are treated nonsurgically with splint therapy. Of 301 TMJs examined, 108 (36%) produced clinically audible clicks on opening, closing, or both. Fluoroscopy and arthrotomography studies for 16 (15%) showed anteriorly displaced menisci without reduction. The mean age of this group was 32 years, with a range of 17-51 years. The duration of the patients' symptoms ranged from three months to eight years (mean 3.7 years). Bilateral degenerative joint disease was noted in 8/16 (50%). Operative findings in four patients suggested the cause of the clicking sound as a frictional impact between the degenerated surface of the condyle and the hypertrophied displaced meniscus. These observations demonstrate that an audible click may not imply a reduction of a displaced meniscus.     

海南粗榧新碱衍生物HH07A的抗肿瘤作用

用细胞生长曲线测定法及软琼脂集落形成分析法研究了HH07A对几种肿瘤及正常细胞生长的影响。结果表明,1.5ug·ml^-1及3μg·ml^-1HH07A能分别明显抑制L1210和HL-60细胞的生长。3种肿瘤细胞对HH07A的敏感性依次为L1210>KB>HL-60,而正常小鼠粒系祖细胞GM-CPC对药物的敏感性则低于前三者,且HH07A3.5μg·ml^-1对HL-60细胞无分化诱导作用。HH07A对腹水型L1210白血病小鼠、S180小鼠均有较明显的治疗作用,使L1210荷瘤小鼠、S180荷瘤小鼠存活时间延长。也能抑制S180实体瘤的生长。     

Influence of HLA-A2 on the effectiveness of platelet transfusions in alloimmunized thrombocytopenic patients

Platelet transfusions from donors selectively mismatched for cross- reactive and certain non-cross-reactive HLA antigens were found to be more effective in HLA-A2 negative than in HLA-A2 positive, alloimmunized thrombocytopenic patients. The two groups of patients responded equally well to platelets matched for antigens of the HLA-A and B loci. Certain alloimmunized patients negative for HLA-A2 continued to respond satisfactorily to platelets selectively mismatched for non-cross-reactive HLA antigens as long as platelets containing HLA- A2 were avoided. The data indicate that platelet transfusion support can be provided within a broader range of donor-recipient HLA antigenic disparity to HLA-A2 negative alloimmunized patients than to those who are positive for this antigen.     

Distal versus proximal electrode placement in the prediction of total body water and extracellular water from multifrequency bioelectrical impedance

In 48 normal weight subjects, 25 females and 23 males, body impedance was measured at multiple frequencies. Two different electrode placements were used, one the commonly used distal electrode placement, in which the source electrodes are on the dorsal sides of the hand and foot and the sensor electrodes are on ankle and wrist, and a second placement, in which the sensor electrodes are placed more proximally, at the knee and elbow. Theoretically a proximal electrode placement could result in more precise estimates of body water compartments. Total body water (TBW) and extracellular water (ECW) were determined using deuterium oxide dilution and bromide dilution, respectively. The aim of the study was to investigate whether proximal electrode placement results in a more precise estimation of TBW and ECW using multifrequency impedance analysis. Correlation coefficients of impedance and the impedance index stature²/impedance) with TBW and ECW were not or were only slightly higher using proximal impedance values, resulting in slight improvement of the estimation error for TBW (0.13 kg) and ECW (0.04 kg). The differences between measured and predicted values (residuals) of TBW and ECW were not correlated with TBW and ECW, but they were correlated with body fat and body water distribution (ECW/TBW). These correlations did not differ between distal and proximal impedance measurements. It is concluded that proximal impedance measurements do not substantially improve the prediction of body water compartments. © 1995 Wiley-Liss, Inc.     

Clinical economics review: gastrointestinal disease in primary care.

Gastrointestinal disorders are common in the general population, with annual prevalence figures ranging from 20% for irritable bowel syndrome to over 40% for dyspepsia. Less than one-third of patients consult general practitioners for these problems, and anxiety about serious disease and cancer are as important in the decision to consult as symptom severity. Gastrointestinal disorders have significant socioeconomic effects in the community, and account for 10% of the work of general practitioners in the UK. The health economics implications of management in primary care relate principally to the costs of investigation and therapy, notably antisecretory drugs, endoscopy, radiology and specialist referral. Although guidelines based on evidence and agreed between primary and secondary care physicians offer an attractive approach to rationalizing the use of resources, there is at present little health service research evidence on which to base important decisions. For example, in dyspepsia, the role of Helicobacter pylori identification and eradication in an overall management strategy in primary care has yet to be defined. An exploration of the clinical economics of gastrointestinal disorders in general practice raises a number of research questions, which will require the attention of both generalists and specialists.