发硒的动态变化与大骨节病早期病变自然修复的关系

研究表明,在自然状态下,儿童大骨节病病情的变化是以人体硒营养变化为基础的骨质病变或修复的变化。早期病变的自然修复与人体发硒含量的升高同步发生,从而为用发硒含量定量地监测和预报病情提供了客观的指标。     

Improvement of prenatal diagnosis of wilson disease using microsatellite markers

This paper describes a case of prenatal diagnosis for Wilson disease (WD) carried out in an at-risk couple of Sardinian descent, following non-directive genetic counselling. Diagnosis was obtained by using eight microsatellites located within or flanking the WD locus, six of which were 100 per cent and two 50 per cent informative. The use of several markers may limit the occurrence of misdiagnosis resulting from recombination or instability of repeats.     

Redox potential EH [Se(VI)/Se(IV)] of aqueous extractof soils from Yongshou Kaschin-Beck diseaseregion and the influence by humic acid

The relation between E_H [Se(VI)/Se(IV)] and pH of soil aqueous extract in Kaschin-Beck disease region and the effects of natural redox agents, namely humic substances, MnO₂ and Fe²⁺, on the redox property of the system were studied. The results indicated that both humic acid and Fe²⁺ could enhance the reducibility of Se(VI) and MnO₂, a limited oxidizability for Se(IV). Fe²⁺ showed a weak reducibility only at low pH value. The reducibilities of three sulfur-containing compounds for Se(VI) were in following order:thioglycollic acid > L-cysteine > sulfide     

虾塘残饵腐解对养殖环境影响的研究Ⅰ. 虾塘底层残饵腐解对水质环境的影响

通过室内模拟实验，研究了虾塘底层残饵腐解对虾池水质的影响和更换虾池海水后底层水质质量的变化和清除覆盖于池底的残饵后池底底层水质的变化。结果表明，由于池底残饵的腐解，使虾池水质变坏， Ｄ Ｏ降至零，ｐ Ｈ 下降至６０ ，达不到生物存活的水平。更换虾池海水后，池底水质仍然受到一定的影响。清除池底残饵后，由于沉积物的吸附作用，大量硫化物又释放出来，仍然严重影响虾池的水质质量。数据表明，在养虾过程中应尽量减少虾饵的残留量并做到每年彻底清洁池底，达到清洁养殖的环境标准     

Evaluation of prenatal diagnosis of congenital heart disease

Prenatal diagnosis performed by fetal ultrasound scan is now a routine part of antenatal care in many countries. That an increasing number of fetal anomalies may be detected on prenatal ultrasound is beyond doubt. What is possible is not, however, always practical, especially when congenital heart diseases (CHDs) are concerned and when whole antenatal populations are screened rather than high-risk groups. Thanks to our registry of congenital anomalies, a retrospective study was undertaken to evaluate the prenatal detection of CHDs by ultrasound scan in 131 760 consecutive pregnancies of known outcome from 1979 to 1988. Only 84 out of 912 malformed fetuses with CHDs without chromosomal anomalies were detected (9.2 per cent). The sensitivity of detection varied from around 38 per cent for malformations such as hypoplastic left heart and single ventricle to around 5 per cent for ventricular and atrial septal defects. The effectiveness of the detection of some forms of major congenital heart disease has increased dramatically since 1987 by including routine examination of the four-chamber view and of the inflow and outflow tracts of the fetal heart. Our results stress the need to obtain a definite clear four-chamber view, to perform scans at ⩾ 18 weeks of gestation, and to train sonographers in order to improve the prenatal detection of CHDs.     

低硒环境中人群对不同形态硒的保留量及其效应的研究

研究了低硒生态环境中有明显早期大骨节病病变的人群服用富硒酵母,亚硒酸钠和肌肉注射硒代二乙酸后体内硒保留量的动态变化。分析了治疗效应与摄入三种形态的硒后硒在体内保留量的关系,并与对照组作了比较。讨论了不同形态硒的生物活性。研究结果是三种形态的硒对早期大骨节病病变均有非常显著的疗效,再一次证明低硒生态环境是大骨节病流行的基础。     

Black spots and female association preferences in a sexual/asexual mating complex (Poecilia, Poeciliidae, Teleostei)

We investigated whether female association preferences for males are influenced by black spot disease (BSD), a parasite induced change of the host phenotype. We compared three different species of fish: a gynogenetic hybrid species, Poecilia formosa (amazon molly) and two sexual species (Poecilia latipinna and Poecilia mexicana), which were involved in the natural hybridisation leading to the amazon molly. Contrary to their sexual relatives, asexual amazon mollies significantly avoided images of males infected with black spot disease. We propose that amazon molly females have direct fitness benefits from choosing healthy males. The adaptive significance of the preference for BSD-uninfected males in the asexual amazon molly is yet unclear but may involve avoidance of predation or parasite infection as well as increased sperm availability.     

Environmental Se–Mo–B Deficiency and its Possible Effects in Jiantou Keshan Disease Area in Shaanxi Province, China

Keshan disease (KD) occurs in a wide geographic belt stretching from the Heilongjiang Province in northeastern China to Yunnan Province in southwestern China, including Huangling County, Shaanxi Province. In order to research relationships between eco-environmental geochemistry and KD pertaining to Se, Mo, B, Zn, Mn, and Cu, this investigation was conducted in the Jiantou KD area in Huangling County, one of the areas in China where the incidence of KD is highest. Environmental samples (rock, soil, plant and childrens hair) were collected from the area. Se in plants is low, ranging from 0.03 to 0.06 µg Se g^–1 in corn, potato and soybean. Se contents in childrens hair are normal or reach the limitation of dangerous level. This study reports 0.18 µg Se g^–1, B <40 µg g^–1, and Mo <1.0 µg g^–1 in aeolian soil, 0.14–0.38 µg Mo g^–1 and 3–8 µg B g^–1 in corn and potato (daily staple food for local human beings in the area). The Jiantou KD area is one where the elements Se, Mo and B are deficient. It is proposed that the deficiency of elements Se, Mo and B may be involved in the pathogenicity of KD with respect to the eco-environmental system because Se, Mo and B are essential micronutrients for plants and human beings. It seems that there is no significant relationship between the Zn–Mn–K–Pb–Ba associations and KD.     

隐孢子虫在水环境中存在水平与灭活技术

介绍了隐孢子虫的介水传播途径与特点、卵囊在水环境中存在水平及有效灭活隐孢子虫技术。隐孢子虫在水环境中显著存在;以饮用水为媒介成为隐孢子虫病传播和暴发流行的重要途径;采取可靠灭活工艺是控制隐孢子虫进入供水系统最重要的屏障。氯化消毒难以有效地灭活隐孢子虫,臭氧和紫外线可获得较理想的灭活效果。臭氧剂量为5～10(mg/L)·min时,灭活率为1-lg(90%);紫外线辐照剂量在9～11mJ/cm2,灭活率为2-lg(99%)。