Discovery of the covalent SARS-CoV-2 Mpro inhibitors from antiviral herbs via integrating target-based high-throughput screening and chemoproteomic approaches.

The main proteases (Mpro ) are highly conserved cysteine-rich proteins that can be covalently modified by numerous natural and synthetic compounds. Herein, we constructed an integrative approach to efficiently discover covalent inhibitors of Mpro from complex herbal matrices. This work begins with biological screening of 60 clinically used antiviral herbal medicines, among which Lonicera japonica Flos (LJF) demonstrated the strongest anti-Mpro effect (IC50 = 37.82 µg/mL). Mass spectrometry (MS)-based chemical analysis and chemoproteomic profiling revealed that LJF extract contains at least 50 constituents, of which 22 exhibited the capability to covalently modify Mpro . We subsequently verified the anti-Mpro effects of these covalent binders. Gallic acid and quercetin were found to potently inhibit severe acute respiratory syndrome coronavirus 2 Mpro in dose- and time- dependent manners, with the IC50 values below 10 µM. The inactivation kinetics, binding affinity and binding mode of gallic acid and quercetin were further characterized by fluorescence resonance energy transfer, surface plasmon resonance, and covalent docking simulations. Overall, this study established a practical approach for efficiently discovering the covalent inhibitors of Mpro from herbal medicines by integrating target-based high-throughput screening and MS-based assays, which would greatly facilitate the discovery of key antiviral constituents from medicinal plants.

Uncovering the anti-obesity constituents in Ginkgo biloba extract and deciphering their synergistic effects.

Obesity has been recognized as a key risk factor for multiple metabolic disorders, including diabetes, cardiovascular diseases and many types of cancer. Herbal medicines have been frequently used for preventing and treating obesity in many countries, but in most cases, the key anti-obesity constituents in herbs and their anti-obesity mechanisms are poorly understood. This study demonstrated a case study for uncovering the anti-obesity constituents in an anti-obesity herbal medicine (Ginkgo biloba extract) and deciphering their synergistic effects via targeting human pancreatic lipase (hPL). Following screening the anti-hPL effects of eighty herbal medicines, Ginkgo biloba extract (GBE50) was found with the most potent anti-hPL activity. Global chemical profiling of herbal constituents coupling with hPL inhibition assay revealed that the bioflavonoids and several flavonoids in GBE50 were key anti-hPL constituents. Among all tested thirty-eight constituents, sciadopitysin, bilobetin, quercetin, isoginkgetin, and ginkgetin showed potent anti-hPL effects (IC50 values <2.5 µM). Inhibition kinetic analyses suggested that sciadopitysin, bilobetin, quercetin, isoginkgetin, and ginkgetin acted as non-competitive inhibitors of hPL, with the Ki values were <2 µM. Docking simulations revealed that four bioflavonoids (sciadopitysin, bilobetin, isoginkgetin, and ginkgetin) could tightly bind on hPL at cavity 2, which it is different from the binding cavity of quercetin on hPL. Further investigations demonstrated that the combinations of quercetin and one bioflavonoid-type hPL inhibitor (sciadopitysin or bilobetin) showed synergistic anti-hPL effects, suggesting that the multi-components in GBE50 may generate more potent anti-hPL effect. Collectively, our findings uncovered the anti-obesity constituents in GBE50, and explored their anti-hPL mechanisms as well as synergistic effects at molecular levels, which will be very helpful for further understanding the anti-obesity mechanisms of Ginkgo biloba.

Traditional Chinese Medicine Formula Jian Pi Tiao Gan Yin Reduces Obesity in Mice by Modulating the Gut Microbiota and Fecal Metabolism.

The current study employed the high-fat diet (HFD) induced murine model to assess the relationship between the effect of Jian Pi Tiao Gan Yin (JPTGY) and the alterations of gut microbiota and fecal metabolism. C57BL/6 mice were used to establish an animal model of obesity via HFD induce. Serum biochemical indicators of lipid metabolism were used to evaluate the pharmacodynamics of JPTGY in obese mice. Bacterial communities and metabolites in the feces specimens from the controls, the Group HFD, and the JPTGY-exposed corpulency group were studied by 16s rDNA genetic sequence in combination with liquid chromatography-mass spectrometry (LC-MS) based untargeted fecal metabolomics techniques. Results revealed that JPTGY significantly decreased the levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and elevated high-density lipoprotein cholesterol (HDL-C). Moreover, JPTGY could up-regulate the abundance and diversity of fecal microbiota, which was characterized by the higher phylum of proteobacteria. Consistently, at the genus levels, JPTGY supplementation induced enrichments in Lachnospiraceae NK4A136 group, Oscillibacter, Turicibacter, Clostridium sensu stricto 1, and Intestinimonas, which were intimately related to 14 pivotal fecal metabolins in respond to JPTGY therapy were determined. What is more, metabolomics further analyses show that the therapeutic effect of JPTGY for obesity involves linoleic acid (LA) metabolism paths, alpha-linolenic acid (ALA) metabolism paths, glycerophospholipid metabolism paths, arachidonic acid (AA) metabolism paths, and pyrimidine metabolism paths, which implied the potential mechanism of JPTGY in treating obesity. It was concluded that the linking of corpulency phenotypes with intestinal flora and fecal metabolins unveils the latent causal link of JPTGY in the treatment of hyperlipidemia and obesity.

An Endotenon Sheath-Inspired Double-Network Binder Enables Superior Cycling Performance of Silicon Electrodes.

Silicon (Si) has been regarded as an alternative anode material to traditional graphite owing to its higher theoretical capacity (4200 vs. 372 mAh g-1). However, Si anodes suffer from the inherent volume expansion and unstable solid electrolyte interphase, thus experiencing fast capacity decay, which hinders their commercial application. To address this, herein, an endotenon sheath-inspired water-soluble double-network binder (DNB) is presented for resolving the bottleneck of Si anodes. The as-developed binder shows excellent adhesion, high mechanical properties, and a considerable self-healing capability mainly benefited by its supramolecular hybrid network. Apart from these advantages, this binder also induces a Li3N/LiF-rich solid electrolyte interface layer, contributing to a superior cycle stability of Si electrodes. As expected, the DNB can achieve mechanically more stable Si electrodes than traditional polyacrylic acid and pectin binders. As a result, DNB delivers superior electrochemical performance of Si/Li half cells and LiNi0.8Co0.1Mn0.1O2/Si full cells, even with a high loading of Si electrode, to traditional polyacrylic acid and pectin binders. The bioinspired binder design provides a promising route to achieve long-life Si anode-assembled lithium batteries.

Exploring the Anti-Pulmonary Fibrosis Mechanism of Jingyin Granule by Network Pharmacology Strategy.

Pulmonary fibrosis (PF) is a clinically common disease caused by many factors, which will lead to lung function decline and even respiratory failure. Jingyin granule has been confirmed to have anti-inflammatory and antiviral effects by former studies, and has been recommended for combating H1N1 influenza A virus (H1N1) infection and Coronavirus disease 2019 (COVID-19) in China. At present, studies have shown that patients with severe COVID-19 infection developed lung fibrotic lesions. Although Jingyin granule can improve symptoms in COVID-19 patients, no study has yet reported whether it can attenuate the process of PF. Here, we explored the underlying mechanism of Jingyin granule against PF by network pharmacology combined with in vitro experimental validation. In the present study, the active ingredients as well as the corresponding action targets of Jingyin granule were firstly collected by TCMSP and literature data, and the disease target genes of PF were retrieved by disease database. Then, the common targets were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, and then a PPI network and an ingredient-target network were constructed. Next, UPLC-MS was used to isolate and identify selected representative components in Jingyin granule. Finally, LPS was used to induce the A549 cell fibrosis model to verify the anti-PF effect of Jingyin granule in vitro. Our results indicated that STAT3, JUN, RELA, MAPK3, TNF, MAPK1, IL-6, and AKT1 were core targets of action and bound with good affinity to selected components, and Jingyin granule may alleviate PF progression by Janus kinase 2/signal transducers and activators of transcription (JAK2/STAT3), the mammalian nuclear factor-κB (NF-κB), the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt), tumor necrosis factor (TNF), and the extracellular signal-regulated kinases 1 and 2 (ERK1/2) signaling pathways. Overall, these results provide future therapeutic strategies into the mechanism study of Jingyin granule on PF.

Eutectic Crystallization Activates Solid-State Zinc-Ion Conduction.

Solid-state zinc (Zn) batteries offer a new candidate for emerging applications sensitive to volume, safety and cost. However, current solid polymeric or ceramic electrolyte structures remain poorly conductive for the divalent Zn2+ , especially at room temperature. Constructing a heterogeneous interface which allows Zn2+ percolation is a viable option, but this is rarely involved in multivalent systems. Herein, we construct a solid Zn2+ -ion conductor by inducing crystallization of tailored eutectic liquids formed by organic Zn salts and bipolar ligands. High-entropy eutectic-networks weaken the ion-association and form interfacial Zn2+ -percolated channels on the nucleator surfaces, resulting in a solid crystal with exceptional selectivity for Zn2+ transport (t Zn 2 + =0.64) and appreciable Zn2+ conductivity (σ Zn 2 + =3.78×10-5  S cm-1 at 30 °C, over 2 orders of magnitude higher than conventional polymers), and finally enabling practical ambient-temperature Zn/V2 O5 metal solid cells. This design principle leveraged by the eutectic solidification affords new insights on the multivalent solid electrochemistry suffering from slow ion migration.

The Internet Hospital Plus Drug Delivery Platform for Health Management During the COVID-19 Pandemic: Observational Study.

BACKGROUND: Widespread access to the internet has boosted the emergence of online hospitals. A new outpatient service called "internet hospital plus drug delivery" (IHDD) has been developed in China, but little is known about this platform. OBJECTIVE: The aim of this study is to investigate the characteristics, acceptance, and initial impact of IHDD during the outbreak of COVID-19 in a tertiary hospital in South China. METHODS: The total number of and detailed information on online prescriptions during the first 2 months after work resumption were obtained. Patients' gender, age, residence, associated prescription department, time of prescription, payment, and drug delivery region were included in the analysis. RESULTS: A total of 1380 prescriptions were picked up or delivered between March 2 and April 20, 2020. The largest group of patients were 36-59 years old (n=680, 49.3%), followed by the 18-35 years age category (n=573, 41.5%). In total, 39.4% (n=544) of the patients chose to get their medicine by self-pickup, while 60.6% (n=836) preferred to receive their medicine via drug delivery service. The top five online prescription departments were infectious diseases (n=572, 41.4%), nephrology (n=264, 19.1%), endocrinology (n=145, 10.5%), angiocardiopathy (n=107, 7.8%), and neurology (n=42, 3%). Of the 836 delivered prescriptions, 440 (52.6%) were sent to Guangdong Province (including 363 [43.4%] to Shenzhen), and 396 (47.4%) were sent to other provinces in China. CONCLUSIONS: The IHDD platform is efficient and convenient for various types of patients during the COVID-19 crisis. Although offline visits are essential for patients with severe conditions, IHDD can help to relieve pressure on hospitals by reducing an influx of patients with mild symptoms. Further efforts need to be made to improve the quality and acceptance of IHDD, as well as to regulate and standardize the management of this novel service.

Metabolic profile of danshen in rats by HPLC-LTQ-Orbitrap mass spectrometry.

Danshen, the dried root of Salvia miltiorrhiza Bunge (Lamiaceae), is one of the traditional Chinese medicines (TCMs) most commonly used for the treatment of cardiovascular and cerebrovascular diseases. However, little is known about the chemical and metabolic profiles of danshen in vitro or in vivo. In particular, more information is needed in relation to the 50% ethanol extracts usually used in danshen formulations such as Fufang Xueshuantong Capsules and Fufang Danshen tablets. High-performance liquid chromatography coupled with a linear ion trap-Orbitrap mass spectrometer (HPLC-LTQ-Orbitrap) provides a sensitive and accurate method for analyzing the composition of samples. This method was used to determine the in vitro and in vivo chemical and metabolic profiles of danshen. Sixty-nine components of danshen extract and 118 components of danshen in rat plasma, urine, feces, and bile were unambiguously or tentatively identified. These results not only revealed the material composition of danshen, but also provided a comprehensive research approach for the identification of multi-constituents in TCMs.

[Distribution of chemical compounds of Fufang Xueshuantong capsule in eyes and kidney of beagle dogs].

Diabetic retinopathy(DR) and diabetic nephropathy(DN) are the most common complications of diabetes, and the main causes of death and disability of diabetes. Clinical reports showed that Fufang Xueshuantong capsule(FXT) had effective curative effect on DR and DN, but there was no report on the distribution of chemical compounds of FXT in beagle dog eyes and kidneys. In this study, FXT was given by gavage administration in Beagle dogs for 3 days, and then their eyeballs and kidneys were taken. The chemical compounds in beagle dog eyes and kidneys were detected by HPLC LTQ-Orbitrap technology. Furthermore, by comparing with the data from retrieving literature and references, the chemical compounds were identified by the accurate mass, retention time (tR), and MS/MS. Fourteen and 19 types of notoginsenosides were respectively identified in eyeballs and kidneys in this study, and these results could lay foundation for clarifying the effective ingredients of FXT in treatment of DR and DN.

[LC-LTQ-Orbitrap analysis on chemical constituents in Scrophulariae Radix extract and their metabolites in rat plasma].

Chemical constituents in extract of Scrophulariae Radix and their metabolites in rat plasma after oral administration were identified by HPLC-LTQ-Orbitrap. Samples were separated by a Venusil MP C18 column using a binary gradient elution. The information on the total ion chromatogram, the extraction chromatogram and the mass spectrogram in a negative mode were synthetically analyzed by comparing the retention time, MS and MS/MS spectra with literature data and some of reference standards to conduct a qualitative study on constituents of Radix Scrophulariae extract in vivo and in vitro. Totally 37 compounds from Scrophularia ningpoensis extract were detected including 12 iridoid glycosides, 20 phenylpropanoids and 5 unknown compounds. In vivo, harpagide, harpagoside and angoroside C were confirmed to enter into the blood in prototype forms. Besides, another 2 prototype compounds and 2 metabolites were detected in rat plasma after oral administration of S. ningpoensis extract. The results are beneficial for the determination of bioactive substances of S. ningpoensis and significant for further studies on S. ningpoensis.

[Phenanthrenes from aerial part of Juncus setchuensis with anxiolyticactivity].

Ten phenanthrenes, two organic acids, one organic acid ester and one flavonoid were isolated from the aerial part of Juncus setchuensis by various chromatographic techniques usingsilica gel, polyamide, Sephadex LH-20 as solid phases, and preparative HPLC. Their structures were identified by MS and NMR spectroscopic data as effusol(1), juncusol(2), juncuenin D(3), dehydroeffusol(4), dehydrojuncusol(5), juncuenin B(6),dehydrojuncuenin B(7), 2-methoxyl-7-hydroxyl-1-methyl-5-vinyl phenanthrene(8), 2-hydroxyl-7-carboxy-1-methyl-5-vinyl-9,10-dihydrophenanthrene(9), 2-hydroxyl-7-carboxyl-1-methyl-5-vinylphenanthrene(10), luteolin(11), vanillic acid(12), daphnetin(13), p-coumaric acid(14), respectively. Compound 13 was isolated from the genus Juncus for the first time and compounds 5, 8-12 were isolated from J. setchuensis for the first time. The elevated plus-maze(EPM) was used to evaluate the anxiolytic activity of compounds 6 and 7. Compound 6 at 5 mg•kg⁻¹ and 10 mg•kg⁻¹ showed anxiolytic activity as well as compound 7 at 10 mg•kg⁻¹ and 20 mg•kg⁻¹.

Observed prevalence of congenital heart defects from a surveillance study in China.

OBJECTIVES: The purpose of this study was to estimate the prevalence of major and minor congenital heart defects among fetuses and neonates using sonography in a general population of 4 areas surrounding Shanghai, China. METHODS: Pregnant women were recruited between April 2004 and December 2005 in Jiaxing City, Suzhou City, Changshu County, and Haining County. All participants could have 3 sonographic examinations performed by specially trained physicians regardless of medical indication: a fetal sonographic screen and fetal echocardiography between 20 and 28 weeks' gestation and neonatal echocardiography. Diagnoses of congenital heart defects were made on the basis of review of all available scans by an international group of experts in pediatric cardiology. Prevalence rates were calculated per 1000 births. RESULTS: Among 4006 scanned fetuses and neonates, there were 75 congenital heart defects, including 12 major defects. The observed prevalence for all congenital heart defects was 18.7 (95% confidence interval, 14.8-23.5) per 1000 births, and the prevalence for major defects was 3.0 (95% confidence interval, 1.6-5.2) per 1000 births. The most common defects were ventricular septal defects (n = 47 [62.7%]), atrial septal defects (n = 14 [18.7%]), tetralogy of Fallot (n = 4 [5.3%]), and hypoplastic left heart syndrome (n = 3 [4.0%]). CONCLUSIONS: The prevalence of all congenital heart defects in the 4 areas of China studied was higher than that reported in other countries, with ventricular septal defects being the most frequent defects. Our data likely reflect a better estimate of the total prevalence of congenital heart defects in China than reported previously.

[Facial nerve decompression through transmastoid, extralabyrinthine, subtemporal approach for management of facial paralysis in temporal bone fracture].

OBJECTIVE: To investigate the clinical outcomes of facial nerve decompression via transmastoid, extra labyrinthine,subtemporal approach for management of facial paralysis in temporal bone fracture. METHOD: Twenty-six cases of traumatic facial paralysis (House-Brackmann grade III-V) hospitalized between January 2006 and April 2008 received facial nerve decompression surgery. There were 4 patients diagnosed as House-Braekmann Grade III, 12 as Grade V in and 10 as Grade VI. The preoperative mean air conduction threshold was 52 dB in 16 cases with longitudinal temporal bone fracture and serious sensorineural heating loss in 10 cases with transverse temporal bone fracture. The fracture lines were detected in 13 cases by temporal bone axial CT scans and ossicular disruption could be determined in 9 cases by virtual endoscopy. The geniculate ganglion,the tympanic and mastoid segment of the facial nerve displayed an irregular morphology in curved planar reformation images of the facial nerve canal. RESULT: All cases had primary healing and no complication occurred. At following-up times ranging from 0.5 to 3 years (average 1.2 years), facial nerve function recovered to House-Brackmann Grades I in 15, II in 6, III in 5. Overall air conduction pure tone averages improved 33 dB. CONCLUSION: Facial nerve decompression with rebuilding of ossicular chain through transmastoid, extralabyrinthine, subtemporal approach is a good approach for the treatment of facial paralysis in temporal bone fracture.

[Study on the association between transforming growth factor alpha gene TaqI variant and cleft lip with or without cleft palate].

OBJECTIVE: To study the association between transforming growth factor alpha gene (TGFalpha) TaqI variant and nonsyndromic cleft lip with or without cleft palate (nsCL/P) in Chinese population. METHODS: TGFalpha TaqI variant was detected using polymerase chain reaction-restriction fragment length polymorphism for DNA samples of the 149 triads with nsCL/P affected child. We performed the Transmission/disequilibrium test and the family-based association study (FBAT) to identify the associations between this variant and risk of nsCL/P. RESULTS: Significant distortion of C2 allele at TGFalpha TaqI locus in nsCL/P groups (P > 0.05) was not found. In the family-based association test, C2 allele and offspring C2C1 genotype was not found to be significantly associated with an increase risk of nsCL/P (P > 0.05). CONCLUSION: Our findings did not suggest an association between offspring TGFalpha TaqI variant and the increased risk of nsCL/P in Chinese population.

[Association between parental transforming growth factor alpha gene TaqI variant, paternal smoking and the cleft lip with or without cleft palate].

OBJECTIVE: To study the association between transforming growth factor alpha gene (TGFalpha) TaqI variant and nonsyndromic cleft lip with or without cleft palate (nsCL/P) in Chinese population, and the interaction with parental smoking. METHODS: TGFalpha TaqI variant was detected using RFLP-PCR for DNA samples of the 170 triads with nsCL/P affected child. We performed the transmission/disequilibrium test (TDT) and the family-based association study (FBAT) to test the associations between this variant and risk of nsCL/P. RESULTS: It was not found significant distortion of C2 allele at TGFalpha TaqI locus in nsCL/P groups (P > 0.05), however, by stratified analysis, we found that the rate of C2 allele transmission among nuclear families whose fathers were smoking was 1/5 (0.062 - 0.711) as compared with that among nuclear families whose fathers were not smoking, and the OR of interaction between TGFalpha variant and parental smoking is 0.102 (0.017 - 0.619). CONCLUSION: The parental smoking may interact with TGFalpha variants of Chinese populations in occurrence of nsCL/P, but it remains to have more investigations.

[Clinical observation on effect of jingling oral liquid in treating infertile patients with varicocele after varicocelectomy].

OBJECTIVE: To observe the clinical effect of Jingling oral liquid (JLOL) in treating infertile patients with varicocele after varicocelectomy. METHODS: Sixty patients were randomly divided into two groups, the 30 patients in the treated group treated by JLOL, and the 30 in the control group treated with intramuscular injection of human chorionic gonadotropine (hCG). RESULTS: The pregnant rate of patient's wife in the treated group was 76.6%, while that in the control group was 40.0%, showing significant difference between them (P < 0.05). The quality of semen was improved in both groups (P < 0.05 or P < 0.01), and the improvement was better in the treated group than that in the control group (P < 0.05). The reproductive hormones were also improved in both groups (P < 0.01). In the treated group, levels of superoxide dismutase (SOD) and zinc in semen increased, and that of cadmium decreased after treatment, as compared with those before treatment, the difference was significant (P < 0.05). CONCLUSION: JLOL could improve and regulate the reproductive hormone disturbance in infertile patients with varicocele after varicocelectomy, enhance their quality of semen and sperm to increase the pregnancy rate of their spouses.

[Study on the association between reduced folate carrier gene polymorphism and congenital heart defects and cleft lip with or without cleft palate].

OBJECTIVE: To study the association between reduced folate carrier gene (RFC1) polymorphism and congenital heart defects (CHD) as well as cleft lip with or without cleft palate (CLP) and to provide epidemiological evidence on genetic markers of CHD and CLP. METHODS: RFC1 (A80G) genotype was detected using RFLP-PCR for blood DNA of the 67 triads with nonsyndromic CHD-affected child, the 82 triads with child-affected cleft lip with or without CLP and the 100 control families without child-affected birth defects. We performed a family-based association test and analyzed the interaction between RFC1 A80G genotype and maternal periconceptional supplementation of folic acid. RESULTS: Offspring of mothers who did not take folic acid had an elevated risk for CHD when comparing with offspring of mothers who did (OR = 2.68, 95% CI: 1.14 - 6.41). There was a statistical association between the risk of CHD and maternal periconceptional folic acid supplementation (chi(2) = 6.213, P < 0.05). In the family-based association test, G allele was positively associated with an increased risk for children CHD (Z = 2.140, P < 0.05) while G allele of RFC1 (A80G) polymorphism might increase the risk for CHD. Elevated risks for either CLP group were not observed between RFC1 genotype using or not using folic acid. CONCLUSION: Our findings suggested that the G allele was likely to be a genetically susceptible allele for CHD. There was possible association between offspring with GG, GA genotype and maternal periconceptional folicacid deficiency.

[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.