[Interventional effect and mechanism of fermentation liquid of Dendrobium officinale leaves on alcoholic hepatitis mice]

Objective: To explore the intervention effect and mechanism of Dendrobium officinale leaf fermentation liquid on alcoholic hepatitis (AH) mice. Methods: Seventy inbred C57BL/6J male mice aged 6-8 weeks were selected and randomly divided into normal group (NG), model group (MG), liquid feed control group (CG), silybum group (SI), low-dose group (DL), medium-dose group (DM), and high-dose group (DH) of Dendrobium officinale fermentation liquid, with 10 mice in each group. NG group was given common feed, CG group was given control feed (LB alcoholic liquid control feed), SI group was given LB alcoholic liquid feed and silybum by gavage, DL, DM and DH groups were given LB alcoholic liquid feed and 25%, 50% and 100% concentration of Dendrobium officinale leaf fermentation liquid by gavage. An AH model was established by feeding LB alcoholic liquid feed for 8 weeks.At week 8, alanine Transaminase (ALT), triglyceride (TG), transferrin (TRF), interleukin (IL)-6, IL-10, and IL-1β, tumor necrosis factor-α(TNF-α), interferon-γ(IFN-γ) were detected in eye blood of mice. Liver tissues were stained with HE, Oil Red O, Prussian blue and immunofluorescence ROS. The contents of glutathione(GSH) and malondialdehyde (MDA) in liver tissue homogenate were detected. To analyze the intervention effect and mechanism of Dendrobium officinale leaf fermentation solution on AH mice, the mRNA and protein relative expression levels of adenylate activated protein kinase (AMPK), AMPKβ1, phosphorylated AMPKβ1 (p-AMPKβ1), tumor suppressor gene p53 (p53), solsolic vector family 7 member 11 (SLC7A11), glutathione peroxidase 4 (GXP4) were detected by polymerase chain reaction (PCR) and Western blot. Results: Compared with MG group, the serum ALT and TG levels in the DL, DM, and DH groups were all reduced [ALT: (45.94±19.85), (45.73±22.62), and (41.68±7.13) vs (75.51±17.76) U/L, respectively; TG: (0.90±0.23), (0.69±0.22) and (0.41±0.20) vs (1.28±0.19) mmol/L, respectively, all P<0.05]; IL-6, IL-1β, TNF-α, IFN-γ were decreased (all P<0.05). The serum TRF and IL-10 levels in the DM and DH groups were increased (all P<0.05). Compared with MG group, the liver tissue MDA of mice in DL, DM and DH groups was decreased [(0.41±0.05), (0.40±0.03), and (0.43±0.14) vs (0.64±0.06)μmol/g, respectively], GSH was increased (all P<0.05). Compared with MG, mRNA expression levels of AMPK (1.36±0.11, 1.61±0.17, 1.68±0.11 vs 0.80±0.12, respectively), SLC7A11 (0.91±0.12, 0.97±0.12, 0.99±0.13 vs 0.60±0.14, respectively) and GPX4 (0.51±0.11, 0.63±0.17, 0.83±0.15 vs 0.42±0.14, respectively) in the liver tissue of DL, DM and DH groups were all increased (all P<0.05). Compared with MG group, DL, DM and DH groups showed the relative expression levels of AMPKβ1, p-AMPKβ1, SLC7A11 and GPX4 were increased in the liver tissue of mice, while the relative expression levels of p53 protein were decreased (all P<0.05). Compared with MG group, DL, DM and DH groups reduced the degree of hepatic steatosis and inflammation in the lobules, while the iron and ROS staining in the liver tissue became lighter. Conclusion: Dendrobium officinale leaf fermentation liquid can alleviate the severity of AH in mice, and its mechanism may be related to the up-regulation of AMPK to inhibiting the p53/SLC7A11/GPX4 mediated Ferroptosis pathway.

[Schistosomiasis control in China from 2012 to 2021: progress and challenges]

Schistosomiasis has been endemic in China for more than 2 000 years, which causes huge morbidity, social and economic burdens. Guided by the national specific strategic programs and criteria for schistosomiasis, tremendous achievements have been gained for schistosomiasis elimination in China. This paper reviews the progress of schistosomiasis control and endemic status of schistosomiasis in China during the period from 2012 to 2021, analyzes the challenges to achieve the goal of schistosomiasis elimination in China by 2030, and proposes suggestions for future schistosomiasis control programs.

[Improving China's public health emergency response based on One Health theory]

With the progress of globalization and the improvement of transportation, a public health emergency can spread across country's boundary in a short period of time from its original place to other areas or regions, posing public health threatens. Public health emergencies not only affect human-animal/plant-environmental health, but also have long-term implications for social development, so the public health emergency response has gone beyond general public health and requires an integrated and comprehensive One Health approach. This paper analyzes the problems and shortcomings of China's current public health emergency response system in a view of One Health and put forward the recommendations based on One Health concept on integrality, collaboration, development and sustainability of public health emergency response. These recommendations can be used as reference to further optimize the response system of public health emergencies in China.

[Clinical characteristics of 272 437 patients with different histopathological subtypes of primary esophageal malignant tumors]

Objective: To characterize the histopathological subtypes and their clinicopathological parameters of gender and onset age by common, rare and sparse primary esophageal malignant tumors (PEMT). Methods: A total of 272 437 patients with PEMT were enrolled in this study, and all of the patients were received radical surgery. The clinicopathological information of the patients was obtained from the database established by the State Key Laboratory of Esophageal Cancer Prevention & Treatment from September 1973 to December 2020, which included the clinical treatment, pathological diagnosis and follow-up information of esophagus and gastric cardia cancers. All patients were diagnosed and classified by the criteria of esophageal tumor histopathological diagnosis and classification (2019) of the World Health Organization (WHO). The esophageal tumors, which were not included in the WHO classification, were analyzed separately according to the postoperative pathological diagnosis. The χ² test was performed by the SPSS 25.0 software on count data, and the test standard α=0.05. Results: A total of 32 histopathological types were identified in the enrolled PEMT patients, of which 10 subtypes were not included in the WHO classification. According to the frequency, PEMT were divided into common (esophageal squamous cell carcinoma, ESCC, accounting for 97.1%), rare (esophageal adenocarcinoma, EAC, accounting for 2.3%) and sparse (mainly esophageal small cell carcinoma, malignant melanoma, etc., accounting for 0.6%). All the common, rare, and sparse types occurred predominantly in male patients, and the gender difference of rare type was most significant (EAC, male∶ female, 2.67∶1), followed with common type (ESCC, male∶ female, 1.78∶1) and sparse type (male∶ female, 1.71∶1). The common type (ESCC) mainly occurred in the middle thoracic segment (65.2%), while the rare type (EAC) mainly occurred in the lower thoracic segment (56.8%). Among the sparse type, malignant melanoma and malignant fibrous histiocytoma were both predominantly located in the lower thoracic segment (51.7%, 66.7%), and the others were mainly in the middle thoracic segment. Conclusion: ESCC is the most common type among the 32 histopathological types of PEMT, followed by EAC as the rare type, and esophageal small cell carcinoma and malignant melanoma as the major sparse type, and all of which are mainly occur in male patients. The common type of ESCC mainly occur in the middle thoracic segment, while the rare type of EAC mainly in the lower thoracic segment. The mainly sparse type of malignant melanoma and malignant fibrous histiocytoma predominately occur in the lower thoracic segment, and the remaining sparse types mainly occur in the middle thoracic segment.

[Progress of schistosomiasis control in People's Republic of China in 2021]

This report presented the endemic status of schistosomiasis and analyzed the data collected from the national schistosomiasis prevention and control system and national schistosomiasis surveillance sites in the People's Republic of China at a national level in 2021. Among the 12 provinces (municipality and autonomous region) endemic for schistosomiasis in China, Shanghai Municipality, Zhejiang Province, Fujian Province, Guangdong Province and Guangxi Zhuang Autonomous Region continued to consolidate the achievements of schistosomiasis elimination, and Sichuan and Jiangsu provinces maintained the criteria of transmission interruption, while Yunnan, Hubei, Anhui, Jiangxi and Hunan provinces maintained the criteria of transmission control by the end of 2021. A total of 451 counties (cites, districts) were found to be endemic for schistosomiasis in China in 2021, with 27 571 endemic villages covering 73 250 600 people at risk of infections. Among the 451 endemic counties (cities, districts), 75.17% (339/451), 22.17% (100/451) and 2.66% (12/451) achieved the criteria of elimination, transmission interruption and transmission control of schistosomiasis, respectively. By the end of 2021, 29 037 cases with advanced schistosomiasis were documented in China. In 2021, 4 405 056 individuals received serological tests and 72 937 were sero-positive. A total of 220 629 individuals received stool examinations and 3 were positive. In 2021, snail survey was performed in 19 291 endemic villages in China and Oncomelania snails were found in 7 026 villages, accounting for 36.42% of all surveyed villages, with 12 villages identified with emerging snail habitats. Snail survey was performed at an area of 686 574.46 hm² and 191 159.91 hm² snail habitats were found, including 1 063.08 hm² emerging snail habitats and 5 113.87 hm² reemerging snail habitats. In 2021, 525 878 bovines were raised in the schistosomiasis endemic areas of China, and 115 437 received serological examinations, with 231 positives detected. Among the 128 719 bovines received stool examinations, no positives were identified. In 2021, there were 19 927 schistosomiasis patients receiving praziquantel chemotherapy, and 729 113 person-time individuals and 256 913 herd-time bovines were given expanded chemotherapy. In 2021, snail control with chemicals was performed in 117 372.74 hm² snail habitats, and the actual area of chemical treatment was 65 640.50 hm², while environmental improvements were performed in snail habitats covering an area of 1 244.25 hm². Data from the national schistosomiasis surveillance sites of China showed that the mean prevalence of Schistosoma japonicum infections were both zero in humans and bovines in 2021, and no S. japonicum infection was detected in snails. The results demonstrate that the overall endemic status of schistosomiasis remained at a low level in China in 2021; however, the progress towards schistosomiasis elimination was slowed and the areas of snail habitats rebounded mildly. Strengthening researches on snail diffusion and control, and improving schistosomiasis surveillance and forecast are recommended to prevent reemerging schistosomiasis.

[Analysis of the new WHO guideline to accelerate the progress towards elimination of schistosomiasis in China]

On February 2022, WHO released the evidence-based guideline on control and elimination of human schistosomiasis, with aims to guide the elimination of schistosomiasis as a public health problem in disease-endemic countries by 2030 and promote the interruption of schistosomiasis transmission across the world. Based on the One Health concept, six evidence-based recommendations were proposed in this guideline. This article aims to analyze the feasibility of key aspects of this guideline in Chinese national schistosomiasis control program and illustrate the significance to guide the future actions for Chinese national schistosomiasis control program. Currently, the One Health concept has been embodied in the Chinese national schistosomiasis control program. Based on this new WHO guideline, the following recommendations are proposed for the national schistosomiasis control program of China: (1) improving the systematic framework building, facilitating the agreement of the cross-sectoral consensus, and building a high-level leadership group; (2) optimizing the current human and livestock treatments in the national schistosomiasis control program of China; (3) developing highly sensitive and specific diagnostics and the framework for verifying elimination of schistosomiasis; (4) accelerating the progress towards elimination of schistosomiasis and other parasitic diseases through integrating the national control programs for other parasitic diseases.

[Decoding the evolution of preventive chemotherapy schemes for schistosomiasis in China to improve the precise implementation of the WHO guideline on control and elimination of human schistosomiasis]

Preventive chemotherapy is one of the pivotal interventions for the control and elimination of schistosomiasis, which is effective to reduce the morbidity and prevalence of schistosomiasis. In order to promote the United Nations' sustainable development goals and the targets set for schistosomiasis control in the Ending the neglect to attain the Sustainable Development Goals: a road map for neglected tropical diseases 2021-2030, WHO released the guideline on control and elimination of human schistosomiasis in 2022, with major evidence-based updates of the current preventive chemotherapy strategy for schistosomiasis. In China where great success has been achieved in schistosomiasis control, the preventive chemotherapy strategy for schistosomiasis has been updated several times during the past seven decades. This article reviews the evolution of the WHO guidelines on preventive chemotherapy and Chinese national preventive chemotherapy schemes, compares the current Chinese national preventive chemotherapy scheme and the recommendations for preventive chemotherapy proposed in the 2022 WHO guideline on control and elimination of human schistosomiasis, and proposes recommendations for preventive chemotherapy during the future implementation of the 2022 WHO guideline, so as to provide insights into schistosomiasis control among public health professionals engaging in healthcare foreign aid.

[One Health: Re-thinking of zoonoses control]

Under the dual pressure of emerging zoonoses and the difficulty in eliminating conventional zoonoses, many uncertainties in global control of infectious diseases are challenging the achievement of sustainable development goals set by the United Nations General Assembly. One Health, developed on the basis of understanding the relationship between human diseases and animal diseases, is conducive to the prevention and control of zoonoses. The connotation of "One Health" is mainly explained by three aspects, namely the systems thinking mode of "unity of environment and man", the practice guidance of "multi-sectoral concert" and the economic evaluation strategy of "cost-effectiveness analysis". One Health approach has been successfully applied in the control of major infectious diseases in China, such as schistosomiasis, leading to remarkable achievements; however, there are still multiple challenges. This review proposes that much attention should be paid to top-level design, the difference between emerging zoonoses and conventional zoonoses, and the dynamic process of One Health governance during the development and application of One Health.

[Current status and challenges for taeniasis and cysticercosis control in China]

In the WHO new road map for neglected tropical diseases 2021-2030, the disease-specific targets are classified into control, elimination as a public health problem, elimination and eradication, and taeniasis and cysticercosis are targeted for control. The overall prevalence of taeniasis and cysticercosis is low in China, and varies remarkably in regions and populations; however, there are many challenges for elimination of taeniasis and cysticercosis in China. Based on previous taeniasis and cysticercosis control programs, developing a sensitive taeniasis and cysticercosis surveillance-response system, updating criteria for diagnosis of taeniasis and cysticercosis, proposing a national guideline for treatment of taeniasis and cysticercosis, and strengthening interdisciplinary and intersectoral communications and collaborations are urgently needed under the One Health concept.

[Progress of researches on approaches for estimating the burden of vector-borne diseases]

The burden of vector-borne diseases refers to the loss and impact of healthy life and social economy due to disability and early death caused by vector-borne diseases, including economic burden and family burden. Disability-adjusted life year (DALY) is a comprehensive measure of the burden of disease. The economic burden of disease is classified into direct economic burden, indirect economic burden and intangible economic burden. Currently, the estimates of direct economic burdens include micro-cost and macro-cost models, and the estimates of indirecteconomic burdens include human resources and friction cost methods, while the intangible economic burden is generally estimated by willingness to pay. The currently available health economics approaches mainly include cost-utility analysis, cost-benefit analysis and cost-effectiveness analysis. This review summarizes the approaches for estimating the burden of malaria and other vector-borne diseases.

[Application of health economics assessment techniques in the prevention and control of important infectious diseases: a review]

Due to the relative shortage of health resources, rational allocation and utilization of health resources is critical to achieving the maximum economic benefits in developing countries, which requires a health economic assessment to meet the needs to balance the competitive requirements of cost reduction and effectiveness enhancement. This review describes the advances in applications of health economic assessment techniques in four major infectious diseases, including AIDS, tuberculosis, hepatitis B and schistosomiasis. Currently, there is no standard economic assessment in the prevention and control of infectious diseases, and notably, the transparency of cost research is limited, which may affect the popularization of the study conclusions. Further health economic assessments of infectious diseases are required to improve the quality, standard and transparency of the economic evaluation through formulating strategies, to improve the standardization of studies, to improve the popularization of the study conclusions and to improve the applicability of the economic evaluation for policies.

[Endemic status of schistosomiasis in People's Republic of China in 2020]

This report presented the endemic status of schistosomiasis in the People's Republic of China at a national level in 2020, and analyzed the data collected from the national schistosomiasis prevention and control system and national schistosomiasis surveillance sites. Among the 12 provinces (municipality and autonomous region) endemic for schistosomiasis in China, Shanghai Municipality, Zhejiang Province, Fujian Province, Guangdong Province and Guangxi Zhuang Autonomous Region continued to consolidate the achievements of schistosomiasis elimination, and Sichuan and Jiangsu provinces maintained the criteria of transmission interruption, while Yunnan, Hubei, Anhui, Jiangxi and Hunan provinces maintained the criteria of transmission control by the end of 2020. A total of 450 counties (cites, districts) were found to be endemic for schistosomiasis in China, with 28 376 endemic villages covering 71 370 400 people at risk of infections. Among the 450 endemic counties (cities, districts), 74.89% (337/450), 21.87% (98/450) and 3.33% (15/450) achieved the criteria of elimination, transmission interruption and transmission control of schistosomiasis, respectively. By the end of 2020, 29 517 cases with advanced schistosomiasis were documented in China. In 2020, 11 117 655 individuals received inquiry examinations and 1 798 580 were positive; 5 263 082 individuals received serological tests and 83 179 were sero-positive. A total of 273 712 individuals received stool examinations and 3 were positive, including one case of acute schistosomiasis. In 2020, snail survey was performed in 19 733 endemic villages in China and Oncomelania snails were found in 7 309 villages, accounting for 37.04% of all surveyed villages, with 15 villages identified with emerging snail habitats. Snail survey covered an area of 736 984.13 hm² and 206 125.22 hm² snail habitats were found, including 1 174.67 hm² emerging snail habitats and 1.96 hm² habitats with infected snails. In 2020, 544 424 bovines were raised in the schistosomiasis-endemic areas of China, and 147 887 received serological examinations, with 326 positives detected, while 130 673 bovines received stool examinations, with no positives identified. In 2020, there were 19 214 patients with schistosomiasis receiving praziquantel chemotherapy, and 964 103 person-time individuals and 266 280 herd-time bovines were given expanded chemotherapy. In 2020, molluscicide treatment was performed in 136 141.92 hm² snail habitats, and the actual area of chemical treatment was 71 980.22 hm², while environmental improvements were performed in snail habitats covering an area of 1 464.03 hm². Data from the national schistosomiasis surveillance sites of China showed that the mean prevalence of Schistosoma japonicum infections were both zero in humans and bovines in 2020, and no S. japonicum infection was detected in snails. The results demonstrate that the overall endemic status of schistosomiasis remains at a low level in China and the goal of the National Thirteenth Five-Year Plan for Schistosomiasis Control was achieved as scheduled; however, the endemic situation of schistosomiasis rebounded in local areas. Precision schistosomiasis control and intensified monitoring of the endemic situation and transmission risk of schistosomiasis are required to be performed to facilitate the progress towards elimination of schistosomiasis steadily.

[Construction of a forecast system for prediction of schistosomiasis risk in China based on the flood information]

OBJECTIVE

To create a model based on meteorological data to predict the regions at risk of schistosomiasis during the flood season, so as to provide insights into the surveillance and forecast of schistosomiasis.

METHODS

An interactive schistosomiasis forecast system was created using the open-access R software. The schistosomiasis risk index was used as a basic parameter, and the species distribution model of Oncomelania hupensis snails was generated according to the cumulative rainfall and temperature to predict the probability of O. hupensis snail distribution, so as to identify the regions at risk of schistosomiasis transmission during the flood season.

RESULTS

The framework of the web page was built using the Shiny package in the R program, and an interactive and visualization system was successfully created to predict the distribution of O. hupensis snails, containing O. hupensis snail surveillance site database, meteorological and environmental data. In this system, the snail distribution area may be displayed and the regions at risk of schistosomiasis transmission may be predicted using the species distribution model. This predictive system may rapidly generate the schistosomiasis transmission risk map, which is simple and easy to perform. In addition, the regions at risk of schistosomiasis transmission were predicted to be concentrated in the middle and lower reaches of the Yangtze River during the flood period.

CONCLUSIONS

A schistosomiasis forecast system is successfully created, which is accurate and rapid to utilize meteorological data to predict the regions at risk of schistosomiasis transmission during the flood period.

[Expert consensus on the strategy and measures to interrupt the transmission of schistosomiasis in China]

Since 2015 when the transmission of schistosomiasis was controlled in China, the country has been moving towards elimination of schistosomiasis, with the surveillance-response as the main interventions for schistosomiasis control. During the period of the 13th Five-Year Plan, the transmission of schistosomiasis had been interrupted in four provinces of Sichuan, Jiangsu, Yunnan and Hubei and the prevalence of schistosomiasis has been at the historically lowest level in China. As a consequence, the goal set in The 13th Five-Year National Schistosomiasis Control Program in China is almost achieved. However, there are multiple challenges during the stage moving towards elimination of schistosomiasis in China, including the widespread distribution of intermediate host snails and complicated snail habitats, many types of sources of Schistosoma japonicum infections and difficulty in management of bovines and sheep, unmet requirements for the current schistosomiasis control program with the currently available tools, and vulnerable control achievements. During the 14th Five-Year period, it is crucial to consolidate the schistosomiasis control achievements and gradually solve the above difficulties, and critical to provide the basis for achieving the ultimate goal of elimination of schistosomiasis in China. Based on the past experiences from the national schistosomiasis control program and the challenges for schistosomiasis elimination in China, an expert consensus has been reached pertaining to the objectives, control strategy and measures for The 14th Five-Year National Schistosomiasis Control Program in China, so as to provide insights in to the development of The 14th Five-Year National Schistosomiasis Control Program in China.

[Key points and research priorities of schistosomiasis control in China during the 14th Five-Year Plan Period]

Schistosomiasis was once endemic in 12 provinces (municipalities, autonomous regions) along and south of the Yangtze River basin, which seriously damages human health and hinders socioeconomic developments in China. Following the concerted efforts for 70 years, remarkable achievements have been gained in the national schistosomiasis control program of China. However, there are still multiple challenges for elimination of schistosomiasis in the country. This paper describes the current status of schistosomiasis and the challenges during the progress towards the elimination of schistosomiasis, and proposes the goals, key points and research priorities of schistosomiasis control in China during the 14th Five-Year Plan Period.

[Endemic status of schistosomiasis in People's Republic of China in 2019]

This report presented the endemic status of schistosomiasis in the People's Republic of China at a national level in 2019, and analyzed the data collected from the national schistosomiasis prevention and control system and 455 national schistosomiasis surveillance sites. Among the 12 provinces (municipality and autonomous region) endemic for schistosomiasis in China, Shanghai, Zhejiang, Fujian, Guangdong and Guangxi continued to consolidate the achievements of schistosomiasis elimination, Sichuan Province achieved transmission interruption, Jiangsu newly achieved the standard of transmission interruption and 5 provinces of Yunnan, Hubei, Anhui, Jiangxi and Hunan maintained transmission control by the end of 2019. There were 450 endemic counties (cities, districts) endemic for schistosomiasis, including 28 500 endemic villages covering 70 667 800 people at risk of infections. Among the 450 endemic counties (citis, districts), 66.89% (301/450), 28.44% (128/450) and 4.67% (21/450) kept the criteria of elimination, transmission interruption and transmission control of schistosomiasis, respectively. By the end of 2019, a total of 30 170 advanced schistosomiasis cases were documented in China. In 2019, a total of 12 090 712 individuals received inquiry examinations and 1 740 764 were positive; 5 158 369 individuals received serological tests and 89 753 were seropositive. A total of 327 475 individuals received stool examinations and 5 were positive, including one case of acute schistosomiasis. In 2019, snail survey was performed in 19 726 endemic villages in China and Oncomelania snails were found in 7 322 villages, accounting for 37.12% of all surveyed villages, with 6 villages with emerging snail habitats. Snail survey covered an area of 585 286.24 hm² and 174 270.42 hm² snail habitats were found, including emerging snail habitats of 64.20 hm²; however, no infected snails were identified. In 2019, a total of 605 965 bovines were raised in the schistosomiasis endemic areas of China, and 183 313 received serological examinations, with 1 176 positives detected, while 134 978 bovines received stool examinations, with 7 positives identified. In 2019, there were 28 557 patients with schistosomiasis receiving praziquantel chemotherapy, and expanded chemotherapy was given to 1 008 083 person-times; there were 7 bovines with schistosomiasis receiving praziquantel chemotherapy, and 296 053 herd-times expanded chemotherapy was given to bovines. In 2019, snail habitats at an area of 128 754.26 hm² were given chemical treatment, and the actual area of chemical treatment was 69 605.55 hm², while environmental improvements were performed in snail habitats covering an area of 2 847.00 hm². Data from the 455 national schistosomiasis surveillance sites of China showed that the mean Schistosoma japonicum infection rates were both zero in humans and bovines in 2019, and no infected snails were found. The results demonstrate that the overall endemic situation of schistosomiasis remains at a lower infection level in China; however, there is still a risk of schistosomiasis transmission. To achieve the target set in the National Thirteenth Five-Year Plan for Schistosomiasis Control and consolidate the achievements of schistosomiasis control, precision control on schistosomiasis still needs to be reinforced in China.

microRNAs expression profiles in Schistosoma japonicum of different sex 14 and 28 days post-infection

Different miRNAs are involved in the life cycles of Schistosoma japonicum. The aim of this study was to examine the expression profile of miRNAs in individual S. japonicum of different sex before and after pairing (18 and 24 dpi). The majority of differential expressed miRNAs were highly abundant at 14 dpi, except for sja-miR-125b and sja-miR-3505, in both male and female. Moreover, it was estimated that sja-miR-125b and sja-miR-3505 might be related to laying eggs. sja-miR-2a-5p and sja-miR-3484-5p were expressed at 14 dpi in males and were significantly clustered in DNA topoisomerase III, Rap guanine nucleotide exchange factor 1 and L-serine/L-threonine ammonia-lyase. Target genes of sja-miR-2d-5p, sja-miR-31- 5p and sja-miR-125a, which were expressed at 14 dpi in males but particularly females, were clustered in kelch-like protein 12, fructose-bisphosphate aldolase, class I, and heat shock protein 90 kDa beta. Predicted target genes of sja-miR-3483-3p (expressed at 28 dpi in females but not in males) were clustered in 26S proteasome regulatory subunit N1, ATPdependent RNA helicase DDX17. Predicted target genes of sja-miR-219-5p, which were differentially expressed at 28 dpi in females but particularly males, were clustered in DNA excision repair protein ERCC-6, protein phosphatase 1D, and ATPase family AAA domaincontaining protein 3A/B. Moreover, at 28 dpi, eight miRNAs were significantly up-regulated in females compared to males. The predicted target genes of these miRNAs were significantly clustered in heat shock protein 90 kDa beta, 26S proteasome regulatory subunit N1, and protein arginine N-methyltransferase 1. To sum up, differentially expressed miRNAs may have an essential role and provide necessary information on clarifying this trematode's growth, development, maturation, and infection ability to mammalian hosts in its complex life cycle, and may be helpful for developing new drug targets and vaccine candidates for schistosomiasis.

[Challenges of schistosomiasis control in China during the coronavirus disease 2019 (COVID-19) epidemic]

OBJECTIVE

To investigate the implementation of schistosomiasis control activities in China during the coronavirus disease 2019 (COVID-19) epidemic, so as to evaluate the impact of COVID-19 epidemic on the national schistosomiasis control program in China.

METHODS

On April 2020, 3 counties (districts) were randomly selected from each of the 12 schistosomiasis-endemic provinces (municipality, autonomous region), and a questionnaire survey was conducted to investigate the implementation of schistosomiasis control activities in these counties (districts) from January to March 2020. Then, the impact of the COVID-19 epidemics on the national schistosomiasis control program of China was evaluated using a comparative analysis approach.

RESULTS

Among the 36 counties (cities, districts) sampled from 12 provinces (municipality, autonomous region), 66.67% were at a high and medium risk of COVID-19 epidemics. The implementation of schistosomiasis control activities assignment, human schistosomiasis examination and treatment, snail control with chemical treatment and health education reduced by 44.26% to 91.56% as compared to 2019 during the same time period, and the schistosomiasis control program was more affected by COVID-19 in transmission-controlled provinces. The gross funds invested into the schistosomiasis control program reduced by 23.39% in relative to the expected, while the total expenditure increased by 41.22%. In addition, all 36 surveyed counties (districts) considered that the COVID-19 epidemic had a short-term impact on the schistosomiasis control program, with the most predominant impact on schistosomiasis control activities assignment, human resources and monitoring of endemic situation of schistosomiasis.

CONCLUSIONS

The COVID-19 epidemics affect the routine schistosomiasis control program across the endemic-foci of China. Policy and financial support should be strengthened to ensure the completion of the schistosomiasis control program.

[Prevalence of soil - borne nematode infections among residents living in urban/town areas of China in 2015]

OBJECTIVE

To understand the prevalence of soil-borne nematode infections among residents living in urban/town areas of China, so as to provide insights into the control and elimination of soil-borne nematodiasis.

METHODS

A total of 5 epidemic areas were classified in China according to the prevalence of human Clonorchis sinensis infections captured from the 2014-2015 national survey on major human parasitic diseases in China, and the total sample size was estimated according to the binomial distribution and Poisson's distribution. Then, the total sample size was allocated proportionally to each province (autonomous region, municipality) of China based on the percentage of residents living in urban and town areas, and the number of survey sites in each province (autonomous region, municipality) was proportionally assigned according to the percentages of residents living in urban and town areas. Then, stratified sampling was performed at county, township and community levels according to the number of sampling sites in each province (autonomous region, municipality), and the survey site (community) was defined as the smallest sampling unit. All permanent residents in the survey sites were selected as the study subjects, and their stool samples were collected for identification and counting of parasite egg using a Kato-Katz technique. The prevalence and intensity of each parasite species were calculated.

RESULTS

From 2014 to 2015, among the 133 231 residents detected in 31 provinces (autonomous regions, municipalities) of China, the overall prevalence of soil-borne nematode infections was 1.23% (1 636/133 231), and the prevalence rates of hookworm, Ascaris lumbricoides and Trichuris trichiura infections were 0.77% (1 032/133 231), 0.32% (426/133 231) and 0.17% (224/133 231), respectively. The highest prevalence of soil-borne nematode infections was seen in Jiangxi (4.03%, 82/2 034) and Chongqing (4.03%, 524/13 012), followed by in Hainan (3.47%, 72/2 075). The prevalence of soilborne nematode infections was 1.07% (662/62 139) in men and 1.37% (974/71 092) in women, and the greatest prevalence was found in residents at ages of 65 to 70 years (2.56%, 219/8 569). With regard to occupations and education levels, herdsmen (2.47%, 2/81) and illiterate residents (3.33%, 226/6 795) were found to have the highest prevalence of soil-borne nematode infections, respectively. In addition, mild infections were predominantly identified in hookworm-, A. lumbricoides- and T. trichiura-infected individuals (all > 90%).

CONCLUSIONS

The overall prevalence of soil-borne nematodiasis remains low in urban and town areas of China; however, human infections are widespread. According to the epidemiological features, health education combined with deworming are recommended to reduce the prevalence of soil-borne nematode infections among residents living in urban and town areas of China.

[Challenges and countermeasures of schistosomiasis control in Hunan Province in the new era]

This paper describes the current epidemic characteristics and endemic status of schistosomiasis, analyzes the main challenges of schistosomiasis control and proposes the emphasis and interventions for future schistosomiasis control activities in Hunan Province, so as to provide insights into the elimination of schistosomiasis in Hunan Province.

[Moving towards a new era in elimination of schistosomiasis in Dongting Lake regions]

Hunan Province occupies a particular position in the history of the national schistosomiasis control programme of China. The province is hyperendemic for schistosomiasis, and achieves great successes and many experiences at various stages of the national schistosomiasis control programme of China. Recently, remarkable schistosomiasis control benefits have been achieved in Hunan Province because of the strong political will, increased financial support, intensification of the integrated control strategy and sustainable implementation of the four projects, including management of livestock and humans as sources of Schistosoma japonicum infections, snail control and capability building of schistosomiasis control institutions. In addition, a series of schistosomiasis control models have been created from the schistosomiasis control programme, and the concept of control-research combination and research serving for field control has been achieved, which provides the "Hunan experience" for the natonal schistosomiasis control programme of China. Based on the government-led multisectoralcollaboration principle, further actions are required with scientific control and joint prevention and control, implementation of the integrated strategy with emphases on controlling sources of S. japonicum infections and snails, adequate financial support, improved professional capability building, and innovative medical treatment-prevention combination patterns, so as to achieve the goal of schistosomiasis elimination in Hunan Province as soon as possible.

[Implications, spiritual characteristics and practical significance of Chinese schistosomiasis control culture]

The culture of schistosomiasis control is specific in the history of Chinese culture. Broadly speaking, the culture of schistosomiasis control is a summary of specific social mood, social consciousness and material culture created by Chinese populations during the progress of schistosomiasis control since the founding of the People's Republic of China. Narrowly speaking, the culture of schistosomiasis control is the spiritual culture that is jointly created and nurtured by schistosomiasis control workers since the founding of the People's Republic of China. The spiritual features of Chinese schistosomiasis control culture are characterized by the patriotism and care about the people, the matter-to-fact attitude, the pioneering and enterprising spirit, and the spirit of sacrifice and dedication. The ultimate goal of the research on the culture of schistosomiasis control is to facilitate the achievement of the strategic goal of Healthy China 2030 as scheduled, accelerate the progress towards elimination of schistosomiasis, and to promote the sustainable development of schistosomiasis control in China.

[A high-quality driver to accelerate the progress towards schistosomiasis elimination by science and technology-led innovation in Jiangsu Province]

Schistosomiasis was once hyper-endemic in Jiangsu Province. During the past seven decades, the professionals working in schistosomiasis control from Jiangsu Province insisted on scientific and precision control all the time, created a series of replicable and generalizable "Jiangsu experiences". These practices have developed a number of tools and approaches that have been employed in schistosomiasis control programs in main endemic foci of China. More importantly, the successful experiences from national schistosomiasis control programs of China have been firstly transferred to Africa by professionals from Jiangsu Province, and remarkable achievements have been obtained for the control of schistosomiasis haematobia in Zanzibar.

[Strategy for the South-South cooperation on schistosomiasis control under the Belt and Road Initiative]

Following the concerted efforts for nearly 70 years, great successes have been achieved in the national schistosomiasis control programme in China. Currently, the national schistosomiasis control programme in China is facing the challenges to solve the problems during the"final mile"stage towards schistosomiasis elimination, and contribute Chinese experiences, Chinese strategy and Chinese wisdom to the global schistosomiasis control programmes, so as to facilitate the transformation of the joint efforts in the Belt and Road Initiative to a high-quality development, thereby well supporting the activities on global health security. This paper analyzes the current global status of schistosomiasis and the challenges of the global schistosomiasis control programmes, describes the basis for the cooperation on schistosomiasis control among the countries along the Belt and Road Initiative, illustrates the challenges for translation of Chinese experiences and techniques in schistosomiasis control to other diseaseendemic countries, and proposes the patterns and prospects of the South-South cooperation on schistosomiasis control under the Belt and Road Initiative.

[Surveillance and control strategy of imported schistosomiasis mansoni: an expert consensus]

In 1980s, Biomphalaria straminea, an intermediate host of Schistosoma mansoni, was found in Shenzhen City, Guangdong Province, China, and currently, this snail has colonized in Shenzhen City and spread to peripheral cities involving of Dongguan and Huizhou. Since imported cases infected with S. mamoni have been reported from time to time in China, Mainland China is facing the potential risk of transmission of schistosomiasis mansoni. With the deepening of the opening-up policy, notably the implementation of the Belt and Road Initiative, there is an increase in the risk of transmission of schistosomiasis mansoni in Mainland China. Increasing the understanding on schistosomiasis mansoni, improving the awareness toward schistosomiasis mansoni prevention and control, and identifying, reporting and managing imported cases with S. mansoni infection or pathogen carriers, are of particular importance to prevent the development of entire life cycle of S. mansoni and the resultant schistosomiasis mansoni transmission in China. To protect public health, a consensus has been reached pertaining to the surveillance and control strategy of imported schistosomiasis mansoni by Chinese infectious disease experts and parasitologists, with aims to improve the awareness and capability for the diagnosis, treatment and control of imported schistosomiasis mansoni among Chinese disease control and prevention institutions and medical institutions, and decrease and even eliminate the risk of schistosomiasis mansoni transmission in China.

[Endemic status of schistosomiasis in People's Republic of China in 2018]

This report presented the endemic status of schistosomiasis in the People's Republic of China at a national level in 2018, and analyzed the data collected from the national schistosomiasis prevention and control system and 453 national schistosomiasis surveillance sites. Among the 12 provinces (municipality and autonomous region) endemic for schistosomiasis in China, 5 provinces (municipality and autonomous region), including Shanghai, Zhejiang, Fujian, Guangdong and Guangxi, continued to consolidate the achievements of schistosomiasis elimination, Sichuan Province achieved transmission interruption and 6 provinces of Yunnan, Jiangsu, Hubei, Anhui, Jiangxi and Hunan achieved transmission control by the end of 2018. There were 450 endemic counties (cities, districts) covering 260 million people, specifically including 28 456 endemic villages covering 70.059 7 million people at risk of infection. Among the 450 endemic counties (cities, districts), 58.44% (263/450), 27.56% (124/450) and 14.00% (63/450) reached the criteria of elimination, transmission interruption and transmission control, respectively. By the end of 2018, a total of 29 214 advanced schistosomiasis cases were documented in China. In 2018, a total of 11.127 6 million individuals received inquiry examinations and 2.062 9 million were positive; 7.191 4 million individuals received serological tests and 138.5 thousand of them were positive, 532.2 thousand individuals received stool examinations and 8 were positive in China. In 2018, snail survey was performed in 19 821 endemic villages and Oncomehania snails were found in 7 321 villages, accounting for 36.94% of all surveyed villages, with 3 newly detected villages with snails in China. Snail survey covered an area of 590 241.01 hm² and 168 319.41 hm² snail habitats were found, including emerging snail habitats of 61.28 hm²; however, no infected snails were identified. In 2018, a total of 646 823 bovines were raised in the schistosomiasis endemic areas of China, and 225 258 received serological examinations, with 2 638 positives detected, while 164 803 bovines received stool examinations, with 2 positives identified. In 2018, there were 90 388 patients with schistosomiasis receiving praziquantel chemotherapy, and expanded chemotherapy was given to 1 490 594 person-times; there were two bovines with schistosomiasis receiving praziquantel chemotherapy, and expanded chemotherapy was given to 352 577 bovine-times; chemical treatment was conducted in an area of 141 660.87 hm², including an actual mollusciciding area of 75 308.26 hm², and environmental improvements were performed in an area of 4 738.37 hm² in China. Data from the 453 national schistosomiasis surveillance sites of China showed that the mean Schistosoma japonicum infection rates were 0.001 5% and zero in humans and bovines in 2018, respectively, and no infected snails were found. The results demonstrate that the endemic situation of schistosomiasis appears a tendency towards a continuous decline in China; however, there is still a risk of schistosomiasis transmission, and challenges remain in achieving the target set in the Thirteenth Five-Year National Plan for Schistosomiasis Control in 2020 in some regions.

[Endemic situation of schistosomiasis in People's Republic of China from 2010 to 2017]

OBJECTIVE

To understand the epidemic trend of schistosomiasis in China from 2010 to 2017 so as to provide the scientific evidence for schistosomiasis elimination.

METHODS

The information of schistosomiasis control nationwide from 2010 to 2017 was collected, including the endemic of population, status of livestock control, and Oncomelania hupensis snail control. Microsoft Excel was applied for datum management and analysis.

RESULTS

From 2010 to 2017, the epidemic of schistosomiasis in China dropped significantly. The decreasing amplitude of estimated number of patients nationwide was 88.46%. Seventy-one acute schistosomiasis patients were reported and 12.68% (9/71) of them were imported. The decreasing rate of cultivated cattle was 50.09%, and the accumulative number of schistosome-infected cattle was 17 239, and the average positive rate of stool examinations decreased from 1.04% to 0.000 22%. The area with snails nationwide was 373 596.18 to 363 068.95 hm², and the new detected area with snails was 46.71 to 1 346.73 hm². The area with schistosome-infected snails was 171.68 hm² in 2012 and it was 9.25 hm² in 2013. In 72 key monitoring points of 7 endemic provinces, there were 17 schistosome positive points of water body in 2010 and 6 points in 2016. There were some high risk-factors related to schistosomiasis transmission including schisto-some-infected cattle, dogs, and field rats, and the field stools, and the pasture in the area with snails in schistosomiasis monitoring points.

CONCLUSIONS

The endemic status of schistosomiasis in China has dropped significantly, and the transmission level is very low. However, the infectious source and risk factors in the endemic environments have not be eliminated. Therefore, the infectious source control, health education, snail control, and transmission monitoring should be strengthened, so as to promote the progress of schistosomiasis elimination.

[Establishment and role of national clonorchiasis surveillance system in China]

Clonorchiasis is one key food-borne parasitic disease in China. Owing to several years'efforts and preparation, the national clonorchiasis surveillance system in China has been established preliminarily since 2016. In this article, the necessity to establish the national clonorchiasis surveillance system is explained. Then, the structure, content and corresponding methods of the surveillance system are briefly introduced. Key points in the surveillance are summarized and the development of surveillance in future is discussed. Furthermore, the contribution of clonorchiasis surveillance in China to the world is also analyzed.

[Epidemiological characteristics of Kala-azar disease in China, during 2005-2015]

Objective: To explore the epidemiological characteristics of Kala-azar disease in China from 2005 to 2015, to provide evidence for the development of related control and measurement strategies. Methods: Data was obtained from Disease Reporting Information System of China CDC, to compare factors on type, distribution, peak season and the age of onset of the cases. Results: Epidemic of Kala-azar had been persistent in China. Number of the reported cases declined in Sichuan and Gansu provinces but two outbreaks had occurred in Xinjiang Uygur autonomous region. The epidemic was confined in few areas. The reported cases were mainly from Xinjiang, Gansu and Sichuan, with the total cases in these three provinces accounted for 95.29% of all the cases seen in the country. The main peak season was from October to November, followed by April. There were significant differences seen in the age distributions of canine Kala-azar, anthroponotic Kala-azar and wildlife-oriented Kala-azar (P<0.05) cases. Majority of the cases involved under 3-year-olds, with peak age in under 1-year-olds for wildlife-oriented Kala-azar. For anthroponotic and canine Kala-azar cases, most of them were seen among the under 10 years old, with the peak among the 5-year-olds. Conclusions: In recent years,Kala-azar had been seen endemic and persistent, in the mid-west regions of China, but with different epidemiological characteristics. Further study on Kala-azar should be carried on to include appropriate measurements and strategies, according to the features of the disease, in the mid-western areas of China.

[Epidemic features and impact factors on hospitalization of Plasmodium vivax in China 2011-2014]

OBJECTIVE

To investigate the epidemiological characteristics and impact factors on hospitalization of Plasmodium vivax (P.vivax) since initiation of national malaria elimination program, so as to facilitate the adjustment of technical guideline in response to the epidemic changing of malaria in China.

METHODS

The data of individual P. vivax case (probable and confirmed) and population during 2011-2014 were collated from China National Notifiable Infectious Disease Reporting Information System, and the data of epidemiological investigation for individual P. vivax case (imported and indigenous) during 2011-2014 were collected from China Parasite Disease Prevention and Control Information System. All of the data didn't include China's Hongkong, Macao, Taiwan and foreign cases. The risk factors on hospitalization were explored by multiple factors variable binary classification unconditioned logistic regression model.

RESULTS

During study period of four years, a total of 5 656 Plasmodium vivax cases were detected. Among them, 69.9% (3 951 cases) were imported cases and 30.1% (1 705 cases) were autochthonous cases. The male cases accounted for 82.7% of all cases. Among the autochthonous cases, 535 cases (31.4%) occurred in the cross-bordering areas, and 577 cases (33.8%) were reported in the junction of difference provinces. The amount of autochthonous cases decreased from 1 363 cases in 2011 to 53 cases in 2014, and the county affected by autochthonous cases was shrunk from 185 counties to 10 counties. The proportion of autochthonous cases introduced by domestic migrants increased constantly, which reached 41.5% in 2014. The imported cases were detected from 614 counties of 30 provinces, who were originated from 57 overseas countries of 4 continents, with Southeast Asia being the leading origins (2 772 cases, 70.2%). There were 1 494 cases hospitalized for treatment, with the male (OR=1.41, 95%CI: 1.16-1.71), 14 years old and younger (OR=2.26, 95%CI: 1.44-3.56), and oversea imported cases (OR=2.73, 95%CI: 2.30-3.25) were the high risk group for hospitalization.

CONCLUSION

The scale and scope of P. vivax occurrence decreased dramatically since initiation of malaria elimination grogram in 2010. However, the risk of P. vivax introduction by the overseas imported cases and domestic migrants should be highlighted.

Screening of early antigen genes of adult-stage Trichinella spiralis using pig serum from different stages of early infection

The goal of this work was to identify novel, early antigens present in Trichinella spiralis. To this end, a cDNA library generated from 3-day old adult worms (Ad3) was immunologically screened using serum from a pig infected with 20,000 muscle larvae. The serum was obtained from multiple, time course bleeds coinciding with early worm development. Seventeen positive clones were isolated using serum obtained at 20 days post infection (dpi). All clones corresponded to one gene that exhibited high sequence identity with the T. spiralis ATP-dependent RNA helicase DDX19B which is involved in parasite growth and development. In addition, nine additional positive clones representing 5 unique genes were identified when the library was screened with 30 dpi serum; four of these five genes displayed high similarity with members of a putative T. spiralis serine protease family known to be involved in host invasion and host-parasite interactions. The remaining gene aligned with the T. spiralis hypothetical ORF 11.30. The identification of these antigens provides potential candidates for the early diagnosis of trichinellosis and for the development of a vaccine against this parasite.

A potential impact of climate change and water resource development on the transmission of Schistosoma japonicum in China

There is growing consensus among climate modellers that the unusual global warming observed in the last decades of the 20th century is primarily forced by human activities, namely greenhouse gas increases in the atmosphere. Global warming will trigger alterations in physical and biological systems, including shifts in the spatio-temporal distribution of disease vectors, but the nature and extent of these changes are poorly understood. The purpose of the present study was to assess the potential impact of climate change and water resource development on the distribution of Oncomelania hupensis, the intermediate host snail of Schistosoma japonicum. We employed two 30-year composite datasets comprising average monthly temperatures collected at 623 observing stations throughout China, spanning the periods 1961-1990 and 1971-2000. Temperature changes were assessed spatially between the 1960s and 1990s for January, as this is the critical month for survival of O. hupensis. Our database shows that January temperatures increased at 590 stations (94.7%), and that China's average January temperature in the 1990s was 0.96 degrees C higher than 30 years earlier. The historical 0-1 degrees C January isotherm, which was considered the approximate northern limit of S. japonicum transmission, has shifted from 33 degrees 15' N to 33 degrees 41' N, expanding the potential transmission area by 41,335 km2. This translates to an additional 20.7 million people at risk of schistosomiasis. Two lakes are located in this new transmission area that form part of the proposed South-North water transfer project. Climate change, coupled with water resource developments in China, may pose additional challenges for the control of schistosomiasis.

A global network for the control of snail-borne disease using satellite surveillance and geographic information systems

At a team residency sponsored by the Rockefeller Foundation in Bellagio, Italy, 10-14 April 2000 an organizational plan was conceived to create a global network of collaborating health workers and earth scientists dedicated to the development of computer-based models that can be used for improved control programs for schistosomiasis and other snail-borne diseases of medical and veterinary importance. The models will be assembled using GIS methods, global climate model data, sensor data from earth observing satellites, disease prevalence data, the distribution and abundance of snail hosts, and digital maps of key environmental factors that affect development and propagation of snail-borne disease agents. A work plan was developed for research collaboration and data sharing, recruitment of new contributing researchers, and means of access of other medical scientists and national control program managers to GIS models that may be used for more effective control of snail-borne disease. Agreement was reached on the use of compatible GIS formats, software, methods and data resources, including the definition of a 'minimum medical database' to enable seamless incorporation of results from each regional GIS project into a global model. The collaboration plan calls for linking a 'central resource group' at the World Health Organization, the Food and Agriculture Organization, Louisiana State University and the Danish Bilharziasis Laboratory with regional GIS networks to be initiated in Eastern Africa, Southern Africa, West Africa, Latin America and Southern Asia. An Internet site, www.gnosisGIS.org, (GIS Network On Snail-borne Infections with special reference to Schistosomiasis), has been initiated to allow interaction of team members as a 'virtual research group'. When completed, the site will point users to a toolbox of common resources resident on computers at member organizations, provide assistance on routine use of GIS health maps in selected national disease control programs and provide a forum for development of GIS models to predict the health impacts of water development projects and climate variation.

Application of geographic information systems and remote sensing to schistosomiasis control in China

Progress in China on developing prediction models using remote sensing, geographic information systems and climate data with historical infection prevalence and malacology databases is reviewed. Special reference is made to the effects of the Yangtze river Three Gorges dam project on environmental changes that may impact changes in the spatial and temporal distribution and abundance of Schistosoma japonicum in China, and the future success of disease control programs.

Genetic and morphological variations in populations of Oncomelania spp in China

Oncomelania snails are the intermediate hoste of Schistosoma japonicum in Asian countries. In order to understand the genetic and morphological variation of Oncomelania snails in mainland China, field snails from 31 localities were collected and investigated by means of allele enzyme electrophoresis and numerical taxonomical technics. Results demonstrated that out of 17 loci examined, seven polymorphic loci were presented. Genetic distance (Nei, 1978) among the populations varied from 0.03 to 0.27. The phenogenetic tree based on UPGMA cluster analysis showed that genetic diversity corresponded to geographic distribution along the Yangtze River, which provided supplementary genetic data about the evolution of Oncomelania spp. A morphological study showed that Mahalanobis' morphological distance ranged from 1.53 to 346.7. Both genetic and morphological data indicated that the diversity among populations of smooth shelled snails was higher than that among populations of ribbed shelled snails. A positive correlation (r = 0.80) between Mahalanobis' morphological distance and genetic distance supports the hypothesis that the different shell phenotypes represent different species or subspecies.

[Changes in the expression of alpha- and beta-myosin heavy chain gene during the development of renal hypertension in rats]

The changes in the expression of cardiac alpha- and beta-myosin heavy chain (MHC) gene of the left ventricle were investigated in two-kidney, one-clip (2K1C) renal hypertensive rats. The results were as follows: (1) When blood pressure was increased, the left ventricle became hypertrophic, alpha-MHC gene expression was reduced and beta-MHC gene expression was increased in 2K1C renal hypertensive rats. (2) When the animal was treated with captopril, angiotensin converting enzyme inhibitor 4 W after operation and then 8 W with removal of the ischemic kidney, the blood pressure was decreased with attendant regression of left ventricular hypertrophy, while the increase in beta-MHC mRNA level was attenuated and the inhibition of alpha-MHC mRNA level was reduced. The above results suggest that the rise in arteral pressure is an important factor in the left ventricular hypertrophy and the MHC gene switch. Renin angiotension system may be involved in the cardiac hypertrophic and MHC gene switch during the development and maintenance of 2K1C renal hypertension.

Effects of furosemide on intracochlear oxygen tension in the guinea pig

The effects of intravenous furosemide on the perilymphatic oxygen tension of the scala tympani (OT) in the guinea pig and the relationship between changes in OT and changes in auditory cortical-evoked responses were studied, as well as changes in cochlear morphology. Furosemide in dosages of 25 mg/kg and 50 mg/kg caused a sharp decline in OT in addition to elevation of the threshold of auditory cortical-evoked responses. Ischemia of the cochlear stria vascularis was also found but without any damage of hair cells at the light microscopic level. Changes in OT were associated with transient threshold elevations and ischemia of the stria vascularis. Improvements in hearing were directly proportional to the recovery of OT.

Divalent cation substitution reveals CD18- and very late antigen-dependent pathways that mediate human neutrophil adherence to fibronectin

We investigated the mechanisms by which Mn2+ alters human neutrophil (PMN) adherence to various connective tissue proteins. Substitution of Mn2+ for Ca2+ and Mg2+ significantly increased adhesion of human PMN to plastic well coated with fibronectin, fibrinogen, and laminin but not gelatin. Anti-CD18 mAb almost completely blocked adherence to laminin, partly blocked adherence to fibrinogen, but did not inhibit adhesion to fibronectin at all. In contrast, anti-very late antigen (VLA)-5 mAb antibodies significantly reduced Mn(2+)-mediated PMN adherence to fibronectin, but not to laminin or fibrinogen, demonstrating that VLA-5-mediated PMN adherence to fibronectin, but not to fibrinogen or laminin. This was supported by experiments in which synthetic GRGDSP peptide significantly inhibited Mn(2+)-mediated adherence to fibronectin, but not to laminin or fibrinogen. Activation of PMN with phorbol ester or C5a stimulated VLA-5-mediated adhesion to fibronectin, but the contribution of VLA-5 to the forces mediating adherence could only be detected when CD18 function was either blocked with mAb, or when CD18 was congenitally absent. VLA-5 mediated adhesion was also more transient than CD18-dependent adhesion. These data further confirm the presence of PMN VLA integrins and demonstrate that PMN VLA-5 contributes to stimulated PMN adherence to fibronectin.

Divalent cation substitution reveals CD18- and very late antigen-dependent pathways that mediate human neutrophil adherence to fibronectin

We investigated the mechanisms by which Mn2+ alters human neutrophil (PMN) adherence to various connective tissue proteins. Substitution of Mn2+ for Ca2+ and Mg2+ significantly increased adhesion of human PMN to plastic well coated with fibronectin, fibrinogen, and laminin but not gelatin. Anti-CD18 mAb almost completely blocked adherence to laminin, partly blocked adherence to fibrinogen, but did not inhibit adhesion to fibronectin at all. In contrast, anti-very late antigen (VLA)-5 mAb antibodies significantly reduced Mn(2+)-mediated PMN adherence to fibronectin, but not to laminin or fibrinogen, demonstrating that VLA-5-mediated PMN adherence to fibronectin, but not to fibrinogen or laminin. This was supported by experiments in which synthetic GRGDSP peptide significantly inhibited Mn(2+)-mediated adherence to fibronectin, but not to laminin or fibrinogen. Activation of PMN with phorbol ester or C5a stimulated VLA-5-mediated adhesion to fibronectin, but the contribution of VLA-5 to the forces mediating adherence could only be detected when CD18 function was either blocked with mAb, or when CD18 was congenitally absent. VLA-5 mediated adhesion was also more transient than CD18-dependent adhesion. These data further confirm the presence of PMN VLA integrins and demonstrate that PMN VLA-5 contributes to stimulated PMN adherence to fibronectin.

Bacterial evasion of the antibody response: human IgG antibodies neutralize soluble but not bacteria-associated group B streptococcal C5a-ase

Most strains of group B streptococci (GBS) possess an enzyme that inactivates the human anaphylatoxin C5a by cleaving a heptapeptide from the carboxyl terminus of C5a. This enzyme, called GBS C5a-ase, has been purified to homogeneity and cleaves and inactivates C5a in physiologic buffer. The enzymatic activity of soluble C5a-ase is completely inhibited, however, in the presence of plasma or serum from normal human adults. The neutralization of soluble C5a-ase by plasma and serum results largely from naturally occurring IgG antibodies directed against C5a-ase. IgG does not neutralize C5a-ase present on intact encapsulated type III GBS but does neutralize the C5a-ase activity associated with a transposon-induced mutant strain of type III GBS that lacks capsule. The location of GBS C5a-ase on the surface of encapsulated type III GBS permits the C5a-ase to inactivate C5a while evading neutralization by IgG antibodies.

Purification of the proteinase from group B streptococci that inactivates human C5a

We previously reported that group B streptococci (GBS) possess a cell-associated activity that inactivates the chemotactic activity generated in zymosan-activated serum by cleaving a specific site within the carboxy termini of C5a and C5adesarg. This inactivates the major chemoattractants for neutrophils that are generated when serum complement is activated. We now report the isolation of the enzyme responsible for the proteolytic cleavage of C5a. Treatment of GBS with mutanolysin, an endo-N-acetyl muramidase, released activity from GBS which destroyed the functional activity of C5a. The soluble activity was purified to homogeneity by hydroxyapatite, ion-exchange and gel-filtration chromatography. Analysis by SDS-PAGE showed that the enzyme (GBS C5a-ase) has an Mr of approx. 120,000. The GBS C5a-ase appears to be a serine esterase on the basis of its sensitivity to di-isopropyl fluorophosphate. This enzyme is distinct from the C5a-cleaving enzyme produced by group A streptococci, since the two bacterial products migrate differently on SDS-PAGE, and lack antigenic cross reactivity. This enzyme may play a role in the pathogenesis of group B streptococcal disease through its ability to rapidly inactivate the potent neutrophil agonist, C5a, at sites of infection.

Recording of the electrocardiogram from the sinus node and direct measurement of the sinuatrial conduction time in children

Using a simple technique, the electrocardiogram from the sinus node, which had been previously recorded in adults, was for the first time derived successfully in 27 of 31 children (87%). The values of the sinuatrial conduction time were then precisely measured directly according to the electrocardiogram from the sinus node. The sinuatrial conduction time measured directly was significantly longer in 6 children with sick sinus syndrome (138.3 +/- 10.3 msec, mean +/- standard deviation) than in 21 normal children (66.9 +/- 14.4 msec, mean +/- standard deviation). No overlap was found between them. Furthermore, comparison was made between the children and the adults (7 cases with sick sinus syndrome, 32 cases with normal sinus nodal function). The results suggested that the electrocardiogram recorded from the sinus node may be a valuable and promising technique for the evaluation of sinus nodal function and in the accurate diagnosis of the sick sinus syndrome in children.

The effect of target tissues on survival and differentiation of mammalian statoacoustic ganglion neurons in organ culture

This study explored the effect of peripheral and central target tissues on the survival and differentiation of murine statoacoustic ganglion neurons. Isolated ganglia, ganglia with otic sensory epithelia, ganglia with rhombencephalic tissue and ganglia with both otic sensory epithelia and rhombencephalic tissues were explanted from 12.5 gestation-day mouse embryos. All explants developed for 14 days in vitro on the surface of HEMA hydrogel substrata. There were significantly fewer differentiated statoacoustic ganglion neurons in isolated ganglion explants (18.5%) than in explants of ganglia with peripheral (97.2%) or central (87.5%) target tissues or in those explants that contained both targets (93.1%). Our results confirm in the developing mouse that both peripheral and central target tissues exert a trophic influence on the survival and cytodifferentiation of statoacoustic ganglion neurons.

HEMA hydrogels as a substratum for culture of inner ear and statoacoustic ganglion explants

The application of 2-hydroxyethylmethacrylate (HEMA) hydrogels in preparing defined culture substrata for the study of inner ear and statoacoustic ganglion-target tissue explants was evaluated. Addition of extracellular matrix proteins (collagen type I or fibronectin) to the HEMA hydrogels was effective in promoting nerve fiber outgrowth from statoacoustic ganglion-target tissue explants. These results although preliminary, demonstrate the property of HEMA hydrogels to embed extracellular matrix components. This ability of the hydrogel culture substratum may be important for the assessment of neurite-promoting activities of extracellular matrix components (e.g. heparan sulfate proteoglycan, laminin, etc.) on in vitro developing statoacoustic ganglion neurons.