Impact of hemochromatosis screening in patients with indeterminate results: the hemochromatosis and iron overload screening study.

PURPOSE: Assess the quality of life impact of receiving indeterminate test results for hemochromatosis, a disorder involving HFE genetic mutations and/or elevated serum transferrin saturation and ferritin. METHODS: The study sample was from the Hemochromatosis and Iron Overload Screening Study, a large observational study of hemochromatosis among primary care patients in the US and Canada using HFE genotype and serum transferrin saturation and ferritin screening. Study subjects included 2,304 patients found with hemochromatosis risk of uncertain clinical significance. Assessed was SF-36 general health and emotional well-being before screening and six weeks after participants received their test results. Health worries were assessed after screening. RESULTS: Of the study subjects, 1,268 participants (51.5%) completed both assessments. Compared to normal controls, those with HFE mutations or elevated serum transferrin saturation and ferritin levels of uncertain significance were more likely to report diminished general health and mental well-being, and more health worries. These effects were associated with participants' belief of having tested positive for hemochromatosis or iron overload. CONCLUSION: Notification of indeterminate results from screening may be associated with mild negative effects on well-being, and might be a potential participant risk in screening programs for disorders with uncertain genotype-phenotype.     

Elderly people's views of an annual screening assessment.

A survey was carried out in order to identify elderly patients' perceptions of their health status, their health worries and their opinions regarding health screening before and after the introduction of an annual screening programme. Pre- and post-assessment self report, structured questionnaires and standardized, objectively scored, functional and medical assessments were used. The cohort was an age and sex stratified, 20% sample of those aged 75 years and over (133 patients). Results showed that 96% of patients before the assessment and 98% of patients afterwards, considered the annual assessment useful. The domiciliary visit by the health visitors resulted in one third of those patients who perceived themselves to be in good health and three quarters of those who perceived themselves to be in poor health becoming less worried about their health. Only two patients became more worried. Half of those objectively assessed as being in the medium health risk group and 68% of those in the high health risk group became less worried about their health after screening. Despite the majority of patients having welcomed the assessment their visit resulted in false, and potentially harmful, reassurance for a considerable number of individuals objectively assessed as being at medium and high health risk. An adverse consequence of health screening in elderly people may be inappropriate reassurance for those objectively assessed to be at risk. However, screening procedures are a means to an end, not an end in themselves. The identification of those at high risk should see subsequent implementation of services, investigations and increased support to relieve suffering, so it may have been that patients felt less anxious because they were anticipating relief of their problems.     

Persistent genetic isolation in outport Newfoundland

The historical development of genetic isolation has been evaluated for three outport Newfoundland study areas. An attempt was made to ascertain all livebirths in each study area, and determine the parentage of each. Data from records of baptism and marriage were used for this, supplemented with other historical and ethnographic information. Parent-offspring migration was used as a measure of genetic exchange between subpopulations within study areas, and gene flow into the study areas. Currently, 1-8% of parents originate outside the study areas; these rates are low compared to earlier periods, and compared to present-day rates for European isolate populations. Average kinship was estimated, to measure genetic relatedness within and between subpopulations of each area and the potential for random inbreeding; these values, which are minimum estimates, are now at historically high levels. Increased migration into the study areas, which would decrease average kinship, is not likely. Thus, any regionally or locally elevated frequencies of deleterious alleles will persist, and must be taken into account in providing genetic counseling and evaluating the utility of local screening programs.     

Dorsal thalamic connections of the ventral lateral geniculate nucleus of rats

In order to understand better the organisation of the ventral lateral geniculate nucleus of the ventral thalamus, this paper has examined the patterns of connections that this nucleus has with various nuclei of the dorsal thalamus in rats. Injections of biotinylated dextran or cholera toxin subunit B were made into the parafascicular, central lateral, posterior thalamic, medial dorsal, lateral dorsal, lateral posterior, dorsal lateral geniculate, anterior, ventral lateral, ventrobasal and medial geniculate nuclei of Sprague-Dawley rats and their brains were processed using standard tracer detection methods. Three general patterns of ventral lateral geniculate connectivity were seen. First, the parafascicular, central lateral, medial dorsal, posterior thalamic and lateral dorsal nuclei had heavy connections with the parvocellular (internal) lamina of the ventral lateral geniculate nucleus. This geniculate lamina has been shown previously to receive heavy inputs from many functionally diverse brainstem nuclei. Second, the visually related dorsal lateral geniculate and lateral posterior nuclei had heavy connections with the magnocellular (external) lamina of the ventral lateral geniculate nucleus. This geniculate lamina has been shown by previous studies to receive heavy inputs from the visual cortex and the retina. Finally, the anterior, ventral lateral, ventrobasal and medial geniculate nuclei had very sparse, if any, connections with the ventral lateral geniculate nucleus. Overall, our results strengthen the notion that one can package the ventral lateral geniculate nucleus into distinct visual (magnocellular) and non-visual (parvocellular) components.     

Increase of fetal arterial blood temperature by reduction of umbilical blood flow in chronically instrumented fetal sheep

The effect of reduced umbilical blood flow rate on fetal core temperature was investigated in five chronically instrumented fetal sheep (gestational age 124 days). On average, fetal-maternal temperature difference increased 0.13±0.02 °C when blood flow rate was decreased to about 1/3 of normal (248±69 ml min^–1) for 30 min. The small temperature rise is the consequence of predominant heat dissipation through the placenta, and of diminished oxygen consumption.     

Controlled study of withdrawal symptoms and rebound anxiety after six week course of diazepam for generalised anxiety

A group of patients suffering from anxiety, as assessed by general practitioners and psychologists using research criteria for generalised anxiety, were treated with either diazepam or placebo double blind for six weeks. This active treatment period was preceded by a one week single blind placebo "wash in" period and followed by a two week single blind placebo "wash out" period. The results suggest that diazepam can produce rebound anxiety and withdrawal symptoms when used in moderate doses and for what has previously been regarded as a safe length of time. If replicated these results have implications for the therapeutic use of benzodiazepines.     

Cross-sectional area measurements by digital subtraction videodensitometry

A method for measurement of absolute cross-section areas in digital images of iodine-opacified vessels was tested in phantoms containing "normal" segments of circular cross-section and either circular or noncircular "stenoses" over a wide range of iodine concentrations. Accuracy varied with iodine concentration, with a slight tendency to overestimate the area at high concentration (185 mg I/ml) and to underestimate at low concentration (23 mg I/ml). Reproducibility was improved at the higher concentrations, with standard deviation ranging from 2% to 7% of the measured value, compared with 7% to 27% at the lowest concentration. Accuracy and reproducibility of area measurements on either normal or stenotic segments were unchanged by rotation of the vessel by up to 25 degrees out of the plane of the image. This method is easily implemented using computerized image processing techniques and has advantages over either manual or automated edge detection because it eliminates the need for an edge criterion and is independent of the viewing projection.     

Randomized Controlled Trial of a Program to Help Latina Mothers Help Their Children Cope with Stress: Effects on Parenting,Child Coping,and Adjustment

Prevention Science - “Madres Apoyando el Desarrollo Emocional de Sus Hijos” (“Mothers Supporting the Emotional Development of Their Children”) is a parenting...     

论生物技术在医药领域的应用

生物技术是一门新兴的、综合的学科。生物技术在医药领域的应用涉及到新药开发、新诊断技术、预防措施及新的治疗技术。文章就以上方面做了扼要综述,展示了其广阔的应用前景。