Unusual patterns of neural tube defects in a high risk region of northern China.

OBJECTIVE: To study the prevalence of different types of neural tube defects (NTDs) in Luliang Prefecture, Shanxi province, where the prevalence of NTDs is unusually high and the correlation between NTDs prevalence and patterns. METHODS: A surveillance population-based birth defects was performed in Luliang Prefecture, Shanxi province. RESULTS: The results of our study showed that the prevalence of NTDs was 2-fold higher in Luliang Prefecture than in other areas of Shanxi province. Unusual patterns of NTDs were found, however, multiple NTDs were relatively common in Luliang Prefecture, accounting for over 13% of all NTDs cases in China. CONCLUSION: The prevalence of NTDs is associated with its patterns.

Correlation between birth defects and dietary nutrition status in a high incidence area of China.

OBJECTIVE: To investigate the association between birth defects and dietary nutrient intake in a high risk area of China. METHODS: A dietary survey was performed and serum folic acid was measured in women whose pregnancy was affected by neural tube defects (NTDs) or unaffected by any birth defects (BDs) in Zhongyang and Jiaokou Counties in Shanxi Province of China. RESULTS: The local average consumption of foods including dark green vegetables, fruits, fat and meat, and nutrient intake (e.g., energy, protein, retinol, riboflavin, vitamin E, and selenium) were lower than the national average level. In women of childbearing age, these regions, the intake of nutrients was much lower than the recommended nutrient intake (9%-77%). The case-control dietary nutrition study of women whose pregnancy was affected by BDs (including NTDs and congenital heart defects) demonstrated that, in early pregnancy, adequate nutrition (i.e., eating meat, fresh vegetables, fruit more than once a week) was a protective factor, while eating germinated potatoes was a risk factor. The geometrical mean (p5-p95) of serum folic acid in women with NTD birth defects was 9.6 nmol/L (3.6, 23.03), which was significantly lower than that in normal women (14.03 nmol/L). CONCLUSION: Women of childbearing age in the two counties of Shanxi Province, China, have a marked insufficient intake of some nutrients, especially folic acid, zinc, vitamins A and B12. This nutrient deficiency may be an important risk factor for the high prevalence of birth defects in these regions. Therefore, adequate dietary nutrition in early pregnancy can prevent BDs.

[Prevalence of vitamin A deficiency in children under six years of age in Tibet, China].

OBJECTIVE: To understand the prevalence of vitamin A deficiency (VAD) among children under six years of age in Tibet, China. METHODS: Totally, 1 257 children under six years of age were selected from two cities, two farming counties, two semi-farming counties and two livestock farming counties with stratified cluster sampling to asses VAD status in Tibet. Family information, children's feeding and disease history in the previous two weeks were collected by questionnaire. Blood specimen was collected from each child and serum was separated for detection of vitamin A concentration with microfluorescent spectrophotometry. RESULTS: Totally, 1 257 children under six years of age were surveyed, with 635 boys, 622 girls, 862 aged over two years, and 98.5% of Tibet nationality. Six cases of night blindness and two cases of xerophthalmia were detected from them, with prevalence of clinical VAD of 0.96%. Eighteen of 1071 mothers with children under six years of age were found suffering from night blindness, accounting for 1.7%. Clinical cases of VAD both in children and mothers came from all four sampling strata. Average serum concentration of vitamin A and prevalence of subclinical VAD (serum vitamin A lower than or equal to 0.70 micromol/L) was 1.15 micromol/L and 5.4% and 1.12 micromol/L and 4.7% in cities and livestock farming counties, respectively, significantly higher than those in farming (1.04 micromol/L and 11.0%) and semi-farming counties (1.05 micromol/L and 12.3%), respectively, as compared to average levels of 1.09 micromol/L and 8.4% in the autonomous region as a whole. Prevalence of subclinical VAD in children under six months and those aged six to eleven months were 22.2% and 13.3%, respectively, significantly higher than those in children aged one year (8.5%), two to three years (5.4%) and four to five years (7.9%), respectively. There was also significant difference in serum level of vitamin A between children at varied ages, but no significant difference both in serum level of vitamin A and prevalence of subclinical VAD between gender was found. CONCLUSIONS: In general, status of VAD in children of Tibet was milder than that at national level. But, moderate subclinical VAD in some areas, such as farming and semi-farming counties, did exist, so vitamin A supplementation aiming to children, especially those under one year of age, in those areas should be urged.

[The recent study and key technologies of an aided endoscopic surgical robot system].

This paper introduces the recent study and development of an aided endoscopic surgical robot system, and discusses its future trends--teleoperative robot system and telesurgery system. In addition, their key technologies are analyzed here in the paper.

[A novel miniature robotic endoscope design for intestinal inspection].

This paper makes a comparison between the traditional endoscope system and the active robotic endoscope system, discusses the human intestine-working conditions of the robotic endoscope system in detail and its design requirements. An active robotic endoscope system based on earthworn-locomotion principles is proposed here and besides, its structure and locomotion mechanism are analyzed. A new method of human intestinal intervention is brought out and it can prevent the robotic endoscope guided by a cone-shaped guide pipe from being jammed or damaged.

Vitamin A deficiency and child feeding in Beijing and Guizhou, China.

BACKGROUND: Vitamin A deficiency (VAD) is one of the three major micronutrient deficiencies in the world. In order to investigate the status of VAD and child feeding in China, we conducted the survey in Beijing city and Guizhou province. METHODS: We included a high socioeconomic area (Beijing) and a low socioeconomic area (Guizhou province) in China in our study. Participants included 1236 randomly selected children aged 0-71 months from stratified clusters (628 in Beijing and 608 in Guizhou), 409 from urban and 827 from rural areas. A food intake frequency questionnaire was used for dietary assessment. Fluorescence microanalysis was carried out to measure serum retinol concentrations. Serum retinol cut-off values of less than 20 microg/dl and 30 microg/dl were defined as sub-clinical VAD and suspected sub-clinical VAD, respectively. RESULTS: No xerophthalmia or night blindness was found. The mean concentration of serum retinol was 31.5 microg/dl in the high socioeconomic group, and 26.5 microg/dl in the low socioeconomic group. Rural infants had lower concentrations of serum retinol compared with the urban ones (26.9+/-8.1 microg/dl vs 31.8+/-7.3 microg/dl). The prevalence of sub-clinical VAD among all the children was 7.8%, and increased to 15.7% in children from the low socioeconomic group. In infants from the high socioeconomic area, the prevalence of suspected subclinical VAD was 38.0%, increasing to 59.5% in infants from the low socioeconomic area. The children from the low socioeconomic area had significantly lower fequency of intake of meat than the children in other groups. The prevalence of suspected sub-clinical VAD was higher in the children with lower consumption frequency of vitamin A rich foods than the children with higher consumption frequency of vitamin A rich foods. CONCLUSIONS: VAD appears to be a moderate public health problem in certain areas of China. In areas with low socioeconomic status, VAD in childrean is more severe, and infants may be the group at the highest risk for VAD. Inadequate intake of vitamin A rich foods may result in VAD. A comprehensive long-term national strategy needs to be fostered in China for the treatment and prevention of the deficiency.

[Occurrence of structural birth defect in high-prevalent areas of China].

OBJECTIVE: This research was to compare the occurrence levels of birth defect, to describe the distribution of primary birth defects in different range of monitored ages and to provide data to China birth-defect monitoring system. METHODS: A retrospective study on birth defect was conducted in two counties, Shanxi province, China, which covered birth defects among fetuses after 20 weeks' gestational age from 2002 through 2004. Data collected on birth defect cases mainly included extrinsic and visceral anomaly. RESULTS: The occurrence rates of the monitored structural birth defects significantly increased with the increase of age. The occurrence rates were 17.6, 34.0, 43.6, and 53.7 per 1000 births, for different statistical range, from 20-week to 27-week gestational age, 7 days, 1 year and 3 years after birth, respectively. The range from 28-week gestational age to 7 days after birth was usually regarded as the routinely monitored range. If the occurrence rate was calculated from the 20-week gestational age, it appeared a 2.1-time increase. However, if the range was changed to 1 or 3 years after birth, the occurrence rate increased to 2.7 or 3.3 times high, respectively. The distribution of time when birth-defect was identified was significantly different by categories with majority of neural tube defect cases diagnosed at antepartum or 7 days after birth. Visceral defects were mainly found at 7 days after birth but increased with age, even some were diagnosed at 1 year after birth. CONCLUSION: The routine Chinese monitoring program might detect approximately 1/3 of those structural birth defects with the base of current technique and monitoring range from 28-week gestational age to 7 days after birth. The result of our findings should be of help to other related studies.