6-formylindolo[3, 2-b]carbazole alters gut microbiota and prevents the progression of ankylosing spondylitis in mice.

Ankylosing spondylitis (AS), is known as a chronic inflammatory autoimmune disease, there is evidence to suggest that gut microbiota disorders may be related to the occurrence and development of AS. Studies have shown that 6-formylindolo[3, 2-b]carbazole (FICZ) has the ability to modulate intestinal homeostasis and inhibit inflammatory responses. The purpose of this work is to evaluate the protective role of FICZ in treating AS and elucidate potential mechanisms. FICZ was administered to the proteoglycan (PG)-induced AS mice for 7 consecutive weeks. The effects of FICZ on AS mice were evaluated by the disease severity, intestinal histopathology, proinflammatory cytokine levels, and intestinal mucosal barrier function. The gut microbiota compositions were profiled through 16S rDNA high-throughput sequencing. We found that FICZ significantly reduced the severity of AS and resulted in the downregulating of TNF-α and IL-17A inflammatory cytokines. Moreover, FICZ ameliorated pathological changes in the ileal and improved intestinal mucosal barrier function. Furthermore, FICZ altered the composition of the gut microbiota by increasing the Bacteroidetes/Firmicutes phylum ratio and enriched the genes related to "glycan biosynthesis and metabolism", thus reversing the process of AS. In conclusion, FICZ suppressed the progression of AS and altered gut microbiota in AS mice, which provided new insight into AS therapy strategy.

Designing a Coupling Agent with Aliphatic Polyether Chain and Exploring Its Effect on Silica/Natural Rubber Nanocomposites under the Action of Non-Rubber Contents.

In order to prepare engineering tires with lower rolling resistance and better wet slip resistance in a more environmentally friendly way. In this study, a series of low volatile organic compound (VOC) Mx-Si69 coupling agents (x = 1, 2, 3, 4, 5, 6, which means the number of ethoxy group in bis-(γ-triethoxysilylpropyl)-tetrasulfide (Si69) substituted by the aliphatic polyether chain) were applied to silica/NR nanocomposites to prepare tire tread with excellent performance. Firstly, M1-Si69 was substantiated as the best choice of Mx-Si69 and Si69 to achieve comprehensive optima in the mechanical properties of silica/NR nanocomposites characterized by dynamic and static mechanical properties. Afterwards, the modification of silica with M1-Si69 induced by Non-Rubber Contents (NRCs) in silica/NR nanocomposites was revealed by comparing the filler network, micromorphology, and mechanical properties of isoprene rubber (IR) and NR nanocomposites. Furthermore, compared with Si69, the M1-Si69 coupling agent was found to conspicuously reduce the energy loss and improve the safety performance of engineering tires according to evaluations of the rolling resistance and dynamic thermomechanical properties of the silica/NR nanocomposites. Finally, the critical function of M1-Si69 in reducing ethanol (a kind of volatile organic compound (VOC)) emissions from the reaction of coupling agent and silica was disclosed by gas chromatography-mass spectrometry.

Anti-TNF-α therapy alters the gut microbiota in proteoglycan-induced ankylosing spondylitis in mice.

Ankylosing spondylitis is a chronic, progressive disease, and its treatment is relevant to the gut microbiota. Anti-tumor necrosis factor-alpha (anti-TNF-α) therapy alters the gut microbiota in many diseases, including inflammatory bowel disease. However, little is known about the effect of TNF-α blocker treatment on the gut microbiota in ankylosing spondylitis. Herein, the effect of a TNF-α blocker on the gut microbiota in proteoglycan-induced arthritis was investigated. Proteoglycan-induced mice were treated with an rhTNFR:Fc solution of etanercept (5 µg/g) for 4 weeks. rhTNFR:Fc treatment attenuated the arthritis incidence and severity of arthritis in the proteoglycan-induced mice and decreased inflammation in the ankle joints and ameliorated ileal tissue destruction. Moreover, high gut permeability occurred, and zonula occludens-1 and occludin protein levels were reduced in proteoglycan-induced mice. These levels were significantly restored by the administration of rhTNFR:Fc. The serum TNF-α and IL-17 levels were also decreased. In addition, flora analysis via 16S rDNA high-throughput sequencing revealed that rhTNFR:Fc treatment restored the gut microbiota composition to a composition similar to that in control mice. In conclusion, anti-TNF-α therapy attenuated proteoglycan-induced arthritis progression and modulated the gut microbiota and intestinal barrier function. These results provide new insights for anti-TNF-α therapy strategies via regulating the gut microbiota in ankylosing spondylitis.

Rifaximin Alters Intestinal Microbiota and Prevents Progression of Ankylosing Spondylitis in Mice.

Recently, accumulating evidence has suggested that gut microbiota may be involved in the occurrence and development of ankylosing spondylitis (AS). It has been suggested that rifaximin have the ability to modulate the gut bacterial communities, prevent inflammatory response, and modulate gut barrier function. The goal of this work is to evaluate the protective effects of rifaximin in fighting AS and to elucidate the potential underlying mechanism. Rifaximin were administered to the proteoglycan (PG)-induced AS mice for 4 consecutive weeks. The disease severity was measured with the clinical and histological of arthritis and spondylitis. Intestinal histopathological, pro-inflammatory cytokine levels and the intestinal mucosal barrier were evaluated. Then, western blot was performed to explore the toll-like receptor 4 (TLR-4) signal transducer and NF-κB expression. Stool samples were collected to analyze the differences in the gut microbiota via next-generation sequencing of 16S rDNA. We found that rifaximin significantly reduced the severity of AS and resulted in down-regulation of inflammatory factors, such as TNF-α, IL-6, IL-17A, and IL-23. Meanwhile, rifaximin prevented ileum histological alterations, restored intestinal barrier function and inhibited TLR-4/NF-κB signaling pathway activation. Rifaximin also changed the gut microbiota composition with increased Bacteroidetes/Firmicutes phylum ratio, as well as selectively promoting some probiotic populations, including Lactobacillales. Our results suggest that rifaximin suppressed progression of AS and regulated gut microbiota in AS mice. Rifaximin might be useful as a novel treatment for AS.

Constructing a Multiple Covalent Interface and Isolating a Dispersed Structure in Silica/Rubber Nanocomposites with Excellent Dynamic Performance.

Realizing and manipulating a fine dispersion of silica nanoparticles (NPs) in the polymer matrix is always a great challenge. In this work, we first successfully synthesized N, N'-bis[3-(triethoxysilyl)propyl-isopropanol]-propane-1,3-diamine (TSPD), which was a new interface modifier, aiming to promote the dispersion of silica NPs. Through Fourier transform infrared spectroscopy, nuclear magnetic resonance analysis, and mass spectroscopy, we verified that TSPD contains together six ethoxy groups at its two ends. Then, we used this TSPD to modify the pure silica NPs, and this modified silica was abbreviated as D-MS, which is realized by the thermal gravimetric analysis examination, scanning electron microscopy analysis, and dynamic light scattering results. It was clearly observed that D-MS NPs are connected to one another but are not conglutinated tightly, exhibiting a novel predispersed structure with around 1-2 nm certain extent of interparticle distance. Next, we fabricated the following four elastomer nanocomposites such as pure silica/natural rubber (NR) composite (PS-NR), D-MS/NR composite (DMS-NR), bis-(γ-triethoxysilylpropyl)-tetrasulfide (TESPT)-modified silica/NR composite (TS-NR), and TESPT-modified D-MS/NR composite (T&DMS-NR) and found that the Payne effect is the smallest for T&DMS-NR via the combination use of the D-MS and the traditional coupling agent TESPT, which is attributed to its best dispersion state evidenced by the transmission electron microscopy results. Moreover, by measuring a series of other important mechanical performances such as the stress-strain curve, the dynamic strain dependence of the loss factor, and the heat build-up, we concluded that the T&DMS-NR system greatly exceeds those of the three other rubber composites. In general, this new approach provides a good opportunity to prepare a silica/rubber composite with excellent properties in mechanical strength and dynamic behavior by tailoring the fine dispersion of NPs.

Silica Modified by Alcohol Polyoxyethylene Ether and Silane Coupling Agent Together to Achieve High Performance Rubber Composites Using the Latex Compounding Method.

The study of preparing silica/rubber composites used in tires with low rolling resistance in an energy-saving method is fast-growing. In this study, a novel strategy is proposed, in which silica was modified by combing alcohol polyoxyethylene ether (AEO) and 3-mercaptopropyltriethoxysilane (K-MEPTS) for preparing silica/natural rubber (NR) master batches. A thermal gravimetric analyzer and Raman spectroscopy results indicated that both AEO and K-MEPTS could be grafted on to the silica surface, and AEO has a chance to shield the mercaptopropyl group on K-MEPTS. Silica modified by AEO and K-MEPTS together was completely co-coagulated with the rubber in preparing silica/NR composites using the latex compounding method with the help of the interaction between AEO and K-MEPTS. The performance of composites prepared by silica/NR master batches was investigated by a rubber process analyzer (RPA), transmission electron microscopy (TEM) and a tensile tester. These results demonstrate that AEO forms a physical interface between silica and rubber, resulting in good silica dispersion in the matrix. K-MEPTS forms a chemical interface between silica and rubber, enhancing the reinforcing effect of silica and reducing the mutual friction between silica particles. In summary, using a proper combination of AEO and K-MEPTS is a user-friendly approach for preparing silica/NR composites with excellent performance.

[Analysis on influencing factors for stunting and underweight among children aged 3 - 6 years in 15 counties of Jiangsu and Zhejiang provinces].

OBJECTIVE: To analyze the influencing factors for stunting and underweight among children aged 3 - 6 years in 15 counties of Jiangsu and Zhejiang provinces so as to provide reference for enhancing growth level among preschool children. METHODS: Data was from the 183 295 records of Children Follow-up Study Project carried out by the Institute of Reproductive and Child Heath of Peking University and the records of related perinatal health care surveillance system in rural areas of 15 counties/cities of Jiangsu and Zhejiang provinces. WHO-NCHS standard was used to assess the childhood physical level of growth. Data of children's birth and their mothers' perinatal health were correlated to determine influencing factors for childhood stunting and underweight. RESULTS: The average stunting rate was 7.95% and underweight rate was 1.55%. Sex, birth weight, preterm birth as well as maternal height, maternal BMI at the first prenatal visit, maternal education and occupation were significantly related to childhood stunting and underweight. Birth weight was the most important influencing factor for childhood underweight. For the groups whose birth weights were < 2500 g and ≥ 2500 g, the rates of underweight were 7.77% and 1.46% respectively. Children with low birth weight were at higher risk for underweight (OR = 3.68, 95%CI: 3.11 - 4.37). Maternal height was the most important influencing factor for childhood stunting. For the groups whose mothers' heights were < 155 cm, 155 - 160 cm, 160 - 165 cm and ≥ 165 cm, the stunting rates were 13.01%, 8.76%, 6.21% and 4.14% respectively. Compared with the ≥ 165 cm group, the < 155 cm group was at higher risk for stunting (OR = 3.08, 95%CI: 2.82 - 3.37). CONCLUSION: Birth weight and maternal height were key factors influencing the growth of children. Perinatal health care and the nutrition status of pregnant mothers should be improved to promote the growth level of preschool children.

Secular trends of hypospadias prevalence and factors associated with it in southeast China during 1993-2005.

BACKGROUND: The aim of this study is to describe the prevalence of hypospadias and its time trends during 1993-2005 in southeast China, and to explore the potential risk factors. METHODS: The study population included all male live and still births (at least 20 weeks of gestation) in 11 cities and counties in Jiangsu and Zhejiang Provinces in Southeast China born during January 1, 1993, through December 31, 2005. RESULTS: Overall prevalence of hypospadias was 5.8 per 10,000 male births and presented an increasing trend during 1993-2005 (with chi(for trend) (2) of 3.94, p = 0.047). Prevalence of coronal hypospadias and those with unknown sites increased from 1.7 and 0.3 per 10,000 male births in 1993 to 3.6 and 1.4 per 10,000 male births in 2005, respectively (with chi(for trend) (2) of 7.29 and 9.05, p = 0.007 and p = 0.002, respectively), but prevalence of perineal hypospadias decreased (with chi(for trend) (2) of 7.13, p = 0.008). Maternal fever during first trimester, birth of twins or more children, and year of birth were independent risk factors for hypospadias, with odds ratios of 4.14 (95% CI, 1.32-12.83), 3.37 (95% CI, 1.73-6.58), and 1.04 (95% CI, 1.00-1.08), respectively, after adjusting for confounding factors with multivariable logistic regression analysis. CONCLUSIONS: Prevalence of hypospadias increased during 1993-2005 in the two provinces in southeast China. Maternal fever in the first trimester and birth of twins or more children are associated with the risk for hypospadias.

[Correlation on hemoglobin concentration and the development of cognition among pre-school children].

OBJECTIVE: Our purpose was to evaluate the association between hemoglobin concentration (Hb) and cognitive ability of children at 4 - 6 years of age in 21 counties/cities in China. METHODS: A total number of 7331 children born during 1993 - 1996 were randomly selected from 21 counties or cities in Hebei, Jiangsu and Zhejiang provinces. Hb concentration of children were measured followed by three tests including full-scale, verbal and performance intelligence quotient (IQ) test performed by Chinese-Wechsler Intelligence Scale for Children, one year later. RESULTS: There were a 0.7 point difference in mean verbal scale IQ (P = 0.144) and a 0.9 point difference in both mean performance and full-scale IQ (P = 0.055 and 0.079, respectively) between anemia and non-anemia groups. Compared with children with non-anemia, children with anemia were 1.3-fold more likely to score poorly in verbal IQ and operational IQ (95%CI: 1.1 - 1.6, 1.1 - 1.5, respectively) and 1.4-fold more likely to have had poor scores in full-scale IQ (95%CI: 1.2 - 1.6) after controlled for children's gender, age at intelligence test, region, parity and mother's IQ, education level, occupation. Participants were divided into 5 sub-groups according to Hb concentration of every 20 percentile. Verbal IQ scores of the lowest (Hb < 110 g/L), moderate (117 g/L /= 130 g/L) were 90.6 +/- 18.1, 94.0 +/- 17.6 and 91.0 +/- 16.4, respectively. Performance IQ scores were 102.2 +/- 15.7, 104.6 +/- 14.8 and 100.5 +/- 14.9, respectively. Full-scale IQ scores were 95.9 +/- 17.3, 99.0 +/- 16.4 and 95.2 +/- 15.6, respectively. Children with both low and high hemoglobin levels did poorly in all intelligence tests than children with moderate Hb concentration (P < 0.001). After controlling for confounding factors, children with the lowest concentration were 1.4-fold more likely to have had poor verbal and performance scores than children with moderate Hb concentration (95%CI: 1.1 - 1.7, 1.1 - 1.8, respectively) and 1.5-fold (95%CI: 1.2 - 1.8) more likely to have had poor full-scale scores than those with moderate Hb concentration. The association between high Hb concentration and low IQ scores disappeared in the multivariate model. CONCLUSION: Low Hb concentration might have adversely affected children's cognitive development.

[Influence of hemoglobin level during early gestation on the development of cognition of pre-school children].

OBJECTIVE: The purpose of this study was to evaluate the effect of hemoglobin (Hb) level during early gestation on the cognitive development of children at 4 - 6 years of age. METHODS: A total number of 3609 children were randomly selected from all the live birth infants whose mothers participated in a community intervention trial during 1993 - 1996 in 13 counties or cities in Jiangsu and Zhejiang provinces. Hb concentration during early gestation was measured at first prenatal examination and intelligence quotients (IQ), including full-scale, verbal and performance were assessed using Chinese-Wechsler Intelligence Scale for Children in 2000 - 2001 when these children had a mean age of 68 months. RESULTS: Compared with children whose mothers were non-anemic during early gestation, children whose mothers were anemic had a 0.6 point higher mean verbal scale IQ, a 0.9 point higher mean performance IQ and a 0.8 point higher mean full-scale IQ. These differences were not statistically significant when children's gender, age at intelligence test, region, parity and mother's IQ, education level and occupation were adjusted for. When mother-child pairs were divided into 5 sub-groups of every 20 percentiles according to Hb concentration during early gestation, verbal IQ scores of the lowest (Hb < 103 g/L), the moderate (110 g/L ≤ Hb < 116 g/L) and the highest Hb concentration group (Hb ≥ 124 g/L) were 91.6 ± 18.9, 92.8 ± 18.2 and 90.3 ± 18.6, respectively. The performance IQ scores were 104.7 ± 15.2, 104.5 ± 14.3 and 103.5 ± 15.1, and full-scale IQ scores were 97.8 ± 17.3, 98.4 ± 16.3 and 96.4 ± 17.4, respectively. After controlling for confounding factors, children whose mothers had highest Hb concentration were 54% (OR = 1.54, 95%CI: 1.13 - 2.11) more likely to have poor verbal scores and 53% (OR = 1.53, 95%CI: 1.10 - 2.12) more likely to have poor full-scale scores than children whose mothers had moderate Hb concentration. No statistical associations were noticed between high Hb concentration and performance scores, or between low Hb concentration during early gestation and verbal, performance as well as full-scale score of pre-school children. CONCLUSION: High maternal Hb concentration during early gestation might adversely affect children's cognitive development.

[Association of pregnancy-induced hypertension with small-for-gestational-age babies].

OBJECTIVE: To examine the association between pregnancy-induced hypertension (PIH) and small-for-gestational-age babies (SGA) in a Chinese population. METHODS: Subjects were women who delivered a singleton baby (gestational weeks: equal to or greater than 28, and less than 42) in four cities or counties in Jiangsu and Zhejiang provinces, China, during the period of 1995 - 2000. A total number of 93 743 women were included. Incidence of SGA was calculated and compared between women with or without PIH and between groups with different severities of PIH. Multiple logistic regression was used to address the relationship between PIH and SGA while controlling for maternal age, occupation, education, parity, BMI, anemia, premature rupture of membranes and fetal sex. The association between PIH and SGA was also examined according to preterm or term delivery. RESULTS: The incidence of SGA in women with PIH (6.0%) was higher than women without (4.5%), and the incidence increased with severities of PIH. The adjusted relative risk rates (95% CI) of SGA in women with mild,moderate and severe PIH were 1.17 (1.01-1.34), 1.69 (1.33-2.14), and 3.50 (2.57-4.77), respectively, when confounders were controlled for. The risk ratios of SGA in women with PIH among women who delivered a preterm baby were higher than those among women who delivered a term baby. CONCLUSION: There seemed a statistical association between PIH and SGA and women with PIH having higher incidence of SGA than those without PIH.

[Study on anemia among premarital women in 6 counties from 1993 to 2003].

OBJECTIVE: To describe the prevalence of anemia and yearly trends (1993-2003) among women who came to the hospitals or maternal and child health units for premarital examinations in 6 counties of Jiangsu and Zhejiang provinces. METHODS: Data were obtained from the records of the premarital examinations in perinatal health care surveillance system that had been established since 1992 in these areas. We reviewed hemoglobin levels of those women who were enrolled in the perinatal health care surveillance system from 1993 to 2003. Anemia was defined according to the WHO (2001) criterion. We calculated the prevalence of anemia and analyzed the yearly trends based on the data of hemoglobin concentration. RESULTS: In the period of 1993-2003, there were 82 995 anemia cases identified among 193,434 women with an overall anemia rate as 42.9%. The rates of anemia were high (65.5%) in 1993 but low (25.8%) in 2003. 99.7% of the anemic women whose hemoglobin concentration were between 80-119.9 g/L. Time trend analysis indicated a significant decline on anemia rate while monthly analysis showed that the prevalence rates were high (48.2%) in September and low in March (39.5%). The results also showed that the prevalence rates of anemia were relatively higher in farmers and workers in rural enterprises, and lower in Han ethnicity than minorities. The higher prevalence rates of anemia were presented among the women with less education, lower body mass index, or at older age. CONCLUSION: For those premarital women in 6 counties of Jiangsu and Zhejiang provinces, the overall anemic rate presented a significant downward trend between 1993 and 2003 while the prevalence of anemia remained high, especially for the women with less education, lower body mass index or older ages.

Cesarean delivery on maternal request in southeast China.

OBJECTIVE: To estimate the incidence of overall cesarean delivery and cesarean delivery on maternal request in southeast China in the past decade. METHODS: We used data from a population-based maternal and child health surveillance system, which covers 21 cities and counties in two provinces in southeast China. We examined the rate of cesarean delivery and cesarean delivery on maternal request in 1.1 million singleton births from 1994 to early 2006. Cesarean delivery on maternal request was defined as a prelabor cesarean delivery for a singleton gestation without contraindications for vaginal delivery at 38 weeks of gestation or later. RESULTS: During the 13-year study period, the percentage of women who had high school or higher education increased from 13% to 46%. The overall cesarean rate increased from 22% in 1994 to 60% in 2003 and moderated to 56% in 2006. The corresponding rates of cesarean delivery on maternal request (per 100 all deliveries) were 0.8%, 22%, and 20%, respectively. The rates varied enormously among cities and counties. In some areas, cesarean delivery on maternal request accounted for half of all cesarean births. The patterns of rate change were diverse and uneven, and the pattern of risk factors changed substantially between 1994 and 2006. Nulliparity, higher education, older maternal age, having been delivered at provincial or county hospitals, and women's occupations were previously associated with rate of cesarean delivery on maternal request. The rate of cesarean delivery on maternal request no longer varies by age, hospital level, or occupation. CONCLUSION: The rate of cesarean delivery increased dramatically in southeast China in the past decade. Cesarean delivery on maternal request was the predominant contributor to the increase. LEVEL OF EVIDENCE: III.

[Study on the third trimester hemoglobin concentrations and the risk of low birth weight and preterm delivery].

OBJECTIVE: To investigate the association between third trimester hemoglobin (Hb) concentrations and the risk of low birth weight and preterm delivery in a Chinese population. METHODS: Subjects were women who delivered in four cities/counties in Jiangsu and Zhejiang provinces, China, during the period of 1995 - 2000. Incidence of low birth weight and preterm delivery was calculated and compared among groups of women with different levels of Hb during the third trimester. Multiple logistic regression was used to address relationships between Hb levels and the risk of preterm delivery and low birth weight while controlling for potential confounding factors. RESULTS: The overall prevalence of anemia during third trimester of pregnancy was 48.2% , mainly consisting of mild and moderate anemia. Mild and moderate anemia did not increase the risk of preterm delivery and low birth weight statistically. The lowest incidence of preterm delivery and low birth weight was found among pregnant women with Hb levels at 90-99 g/L. The risk for preterm delivery and low birth weight increased with either increasing or decreasing hemoglobin concentrations. However,there was no remarkable elevation of the risk when Hb was in the range of 70-119 g/L. Women with severe anemia (Hb< 70 g/L) had 80% higher risk (95% CI:1.0-3.3) of preterm delivery and a 4.0-fold higher risk (95 % CI :2. 1-7.5) of low birth weight compared with women with an Hb value of 90-99 g/L. In addition, women with a high Hb concentration (Hb> 130 g/L) had 20% higher risk (95 % CI: 1..0-1.4) of preterm delivery and 50 % higher risk (95 % CI: 1.2-1.9) of low birth weight. CONCLUSION: A U-shape relationship was found between Hb concentration and the risk of preterm delivery and low birth weight. Severe anemia and high hemoglobin concentration were both associated with increased risk of preterm deliveries and low birth weight.

[Prevalence of preterm birth among singletons in 10 counties (cities) of China, 1993-2005].

OBJECTIVE: To describe the secular trends and epidemiological characteristics of preterm birth among singletons in 10 counties (cities) of China during 1993-2005. METHODS: We analyzed data on 542 923 women (gestational age > or =28 weeks) collected through Perinatal Healthcare Surveillance System established by the Institute of Reproductive and Child Health, Peking University. Chi-square tests were employed to test the differences in prevalence of preterm birth among different groups. RESULTS: 25 784 preterm births were identified, including 1530 stillbirths. Preterm birth rate was 4.75% (95% CI:4.69-4.81) for all births and 4.49% (95% CI:4.44-4.55) for live births. Preterm birth rate declined steadily from 1993 to 2005 and had no significant seasonal variation. Preterm birth rate from the urban areas of the Southern part of the country,was higher than that in the rural areas which was also higher than that seen in the rural areas from the northern part of the country. Relations between women's age at delivery and preterm birth appeared to be U-shaped. Increased preterm birth rates were also observed in women with lower education level,more parities,and previous history of preterm birth or abortion. CONCLUSION: Preterm birth rate decreased steadily from 1993-2005 in 10 counties (cities) but varied by areas of the country.

Extremely high prevalence of neural tube defects in a 4-county area in Shanxi Province, China.

BACKGROUND: In the past, northern China's Shanxi Province has reported the highest incidence of neural tube defects (NTDs) in the world. However, little is known about the epidemiology of NTDs in this area in recent years. METHODS: Data were collected from a population-based birth defects surveillance system in 4 counties that captures information on all live births, stillbirths of at least 20 weeks' gestation, and pregnancy terminations at any gestational age resulting from prenatal diagnosis of a birth defect. We also surveyed mothers of NTD case patients to determine their use of folic acid before and during early pregnancy. RESULTS: During 2003, 160 NTD cases were identified among 11,534 births (NTD birth prevalence = 138.7/10,000 births). The rates of anencephaly, spina bifida and encephalocele were 65.9, 58.1, and 14.7 per 10,000, respectively, and a female predominance was observed among anencephaly cases (male-to-female relative risk [RR], 0.49; 95% confidence interval [CI], 0.30-0.79), but not among spina bifida (RR, 0.90; 95% CI, 0.55-1.45) and encephalocele (RR, 1.03; 95% CI, 0.40-2.69) cases. The percentages of pregnancy termination following prenatal diagnosis of anencephaly, spina bifida, and encephalocele were 50%, 41.8%, and 35.3%, respectively. NTD birth prevalence tended to be higher among mothers aged <20 or > or =30 years (P = .06) and was markedly associated with lower levels of maternal education (P < .001). Among 143 NTD mothers, only 6 (4.2%) used folic acid supplements during the periconceptional period. CONCLUSIONS: The NTD birth prevalence rate in the study area is among the highest worldwide. Folic acid deficiency may be one important risk factor.

[The current status and the changing patterns of perinatal health care in some southern and northern areas of China, 1994 - 2000].

OBJECTIVE: To understand the current status and its changing patterns of perinatal health care in some southern and northern areas of China from 1994 to 2000. METHODS: Data was collected in 13 counties/cities covered by Perinatal Health Care Surveillance System which was part of the Sino-American cooperative project on neural tube defects prevention, established in 1992. The study population consisted of 368 589 women who delivered single live births of at least 20 gestational weeks from 1994 through 2000. Chi-square test was employed to test the difference on the proportions of women with prenatal checkup, women with early prenatal care onset, women with at least five prenatal visits, hospital delivery versus home delivery as well as the proportion of women with at least three postpartum visits. Two-way ANOVA was used to test the differences of mean of gestational weeks at first prenatal visit and the mean of prenatal visits between different year and areas. RESULTS: The proportion of women with prenatal checkup remained over 99.0% from 1994 through 2000. The mean of gestational weeks at first prenatal visit changed from 13.1 weeks in 1994 to 10.7 weeks in 2000. The proportions of women with early prenatal care onset increased from 65.5% in 1994 to 79.4% in 2000 while women with at least five prenatal visit increasing from 34.1% to 71.8%, hospital delivery increasing from 91.3% to 98.8%, home delivery decreasing from 5.6 % to 0. 6%, women with at least three postpartum visits increasing from 80.5 % to 95.1%. Except for the proportion of women with early prenatal care onset, other proportions in northern areas were lower than those in southern areas in the same year. Greater differences between urban and rural areas in northern areas were found than in southern areas. CONCLUSION: The utilization of perinatal health care services was greatly improved in both southern and northern areas from 1994 to 2000. However, there were still obvious differences in the perinatal health care services between northern and southern areas as well as between urban and rural areas in northern China.

[Study on the descriptive epidemiology of pregnancy-induced hypertension from 1995 - 2000 in Jiaxing of Zhejiang province, China].

OBJECTIVE: To describe the epidemiological characters of pregnancy-induced hypertension (PIH) in Jiaxing areas of Zhejiang province of China between 1995 and 2000. METHODS: We analyzed the perinatal health surveillance data that was collected as part of the Sino-American cooperative project on neural tube defects prevention established in 1992. The study population consisted of 136 070 pregnant women with at least 20 weeks of gestational age. National diagnostic criteria were used to identify the cases which were divided into three subgroups: mild, moderate and severe. RESULTS: 15 127 cases were identified and the overall incidence rate of PIH was 11.1% (95% CI : 11.0% - 11.3%). Among all the cases, mild, moderate and severe PIH were accounted for 71.4%, 22.3% and 6.3%, respectively. The proportions of PIH cases that occurred in the second trimester, third trimester and during delivery appeared to be 4.2%, 34.4% and 61.4%, respectively. There was a significant fall in the trend of PIH occurrence every year, which dropped from 10.7% in 1995 to 8.6% in 2000 by 19.6%. More risk of PIH seemed to be related to those mothers living in the urban areas with age under 20 or above 35, being peasants and having little educational, having had multiple gestations, conceiving in spring/summer or delivering in winter or spring etc. Compared with the results of national survey in 1988, the incidence rate of PIH was higher by 18.1%, while the proportion of severe PIH was much lower by 68.8%. Although the incidence rates of PIH in urban and rural areas were somehow similar, the proportion of severe PIH in rural areas was much higher than that in urban areas. CONCLUSION: Overall incidence rate and distribution of PIH were reported. Compared with the results in 1988, incidence rate of PIH was much higher, particularly for mild cases.

[Comparative study of the detection of plasma folate with microbial assay and radioimmunoassay].

OBJECTIVE: To compare two methods (microbial assay and radioimmunoassay) for measuring plasma folate concentrations, and to examine the relationship between plasma folate levels, and alcohol consumption, tobacco use and body mass index, and the risk of hyperhomocysteinemia in China. METHODS: We used a microtiter plate microbial assay and a radioimmunoassay to measure the folate concentration in 88 plasma samples. After comparing the results of these two methods and fitting a regression line, we examined the geographical, seasonal, and gender differences in folate concentration of plasma collected from 2,422 adults in south and north areas in China, and evaluated the association of plasma folate concentration, with alcohol consumption, cigarette smoking, and body mass index, and with the risk of hyperhomocysteinemia, using the data from the two assays. RESULTS: The data from the two assays had a linear relationship (r=0.879, P=0.000); the regression was Y=0.683X+0.308 (where X and Y were nature logarithmic transformations of plasma folate by microbial assay and radioimmunoassay, respectively); however, the mean plasma folate levels by microbial assay were much higher than those obtained by radioimmunoassay. Both data sets showed similar plasma folate distributions among Chinese adults, associations with other risk factors, and the risk of hyperhomocysteinemia. We estimated that 19.9% of the Southerners and 67.1% of the Northerners had plasma folate concentrations by radioimmunoassay lower than the 6.8 nmol/L used to define plasma folate deficiency. CONCLUSION: There is a linear relationship between plasma folate levels determined by microbial assay and radioimmunoassay, but because of the different levels obtained in the two assays, it is difficult to use the microbial assay results to evaluate folate status at this time. The use of 10.5 nmol/L as a cut-off for plasma folate deficiency by microbial assay needs further study.

[The epidemiology of neural tube defects in high-prevalence and low-prevalence areas of China].

OBJECTIVE: To describe the epidemiology of neural tube defects (NTDs) in high- and low-prevalence areas of China. METHODS: Birth defects surveillance data, collected from 1992 through 1994 was analyzed. These data were collected as part of the Sino-American cooperative project on NTDs prevention. We classified NTDs as anencephaly, encephalocele, high-level and low-level spina bifida (SB) according to location of the lesion (high vs low) and whether the defect was isolated or occurred in association with other birth defects. Rates were compared in the high-prevalence (North) region and the low-prevalence (South) region, after adjusted for classification, urban and rural, season and sex, and calculated the adjusted rate of NTDs. RESULTS: Among seven hundred and eighty-four NTDs cases in 326 874 recorded births (include in livebirth, stillbirth and fetal death with a gestational age of at least 20 weeks), the overall NTDs prevalence in the North was 5.57/1,000 births, and in the South was 0.88/1 000. There were also significant differences in the prevalence of anencephaly, encephalocele, high-level and low-level SB between North (0.97, 0.49, 2.75 and 1.11/1,000 birth) and South (0.36, 0.15, 0.21 and 0.14/1,000 birth) (P < 0.01), with adjusted prevalences in the North 3 - 7 times higher than those in the South. There were significant difference between urban (2.04) and rural areas (6.57/1,000 birth) in the North (P < 0.01), urban (0.52) and rural areas (0.95/1,000 birth) in the South (P < 0.05). Adjusted prevalence rates in the rural were 3 - 4 times higher than those of urban in the North and 1.6 - 1.9 times higher than in the South; The seasonal rate of high-level SB increased between September and November in the North (3.44/1,000 birth), while the seasonal rate of anencephaly decreased between September and November (0.18/1,000 birth) in the South. However there were no seasonal changes in other classified NTDs both in the South and North. CONCLUSIONS: The birth prevalence of NTDs in the North of China was the highest in the world. There were significant differences between the North and the South, urban and rural. There was seasonal change in high-level SB in the North, which was in accordance to the phenotype of NTDs. It was suggested that there might exist etiological heterogeneity among anecephalus, low- and high-level SB.