h-MBenes: Promising Two-Dimensional Material Family for Room-Temperature Antiferromagnetic and Hydrogen Evolution Reaction Applications

Recently, a new class of two-dimensional (2D) hexagonal transition-metal borides (h-MBenes) was discovered through a combination of ab initio predictions and experimental studies. These h-MBenes are derived from ternary hexagonal MAB (h-MAB) phases and have demonstrated promising potential for practical applications. In this study, we conducted first-principles calculations on 15 h-MBenes and identified four antiferromagnetic metals and 11 electrocatalysts for the hydrogen evolution reaction (HER). Notably, the h-MnB material exhibited a remarkable Néel temperature of 340 K and a high magnetic anisotropy energy of 154 μeV/atom. Additionally, the hydrogen adsorption Gibbs free energies (ΔGH*) for h-ZrBO, h-MoBO, and h-Nb2BO2 are close to the ideal value of 0 eV, indicating their potential as electrochemical catalysts for HER. Further investigations revealed that the electronic structure, Néel temperature, and HER activity of the studied h-MBenes can be tuned by applying biaxial strains. These findings suggest that h-MBenes have wide-ranging applicability in areas such as antiferromagnetic spintronics, flexible electronic devices, and electrocatalysis, thereby expanding the potential applications of 2D transition-metal borides.

Machine Learning-Accelerated Discovery of A2BC2 Ternary Electrides with Diverse Anionic Electron Densities

This study combines machine learning (ML) and high-throughput calculations to uncover new ternary electrides in the A2BC2 family of compounds with the P4/mbm space group. Starting from a library of 214 known A2BC2 phases, density functional theory calculations were used to compute the maximum value of the electron localization function, indicating that 42 are potential electrides. A model was then trained on this data set and used to predict the electride behavior of 14,437 hypothetical compounds generated by structural prototyping. Then, the stability and electride features of the 1254 electride candidates predicted by the model were carefully checked by high-throughput calculations. Through this tiered approach, 41 stable and 104 metastable new A2BC2 electrides were predicted. Interestingly, all three kinds of electrides, i.e., electron-deficient, electron-neutral, and electron-rich electrides, are present in the set of predicted compounds. Three of the most promising new electrides (two electron-rich, Nd2ScSi2 and La2YbGe2, and one electron-deficient Y2LiSi2) were then successfully synthesized and characterized experimentally. Furthermore, the synthesized electrides were found to exhibit high catalytic activities for NH3 synthesis under mild conditions when Ru-loaded. The electron-deficient Y2LiSi2, in particular, was seen to exhibit a good balance of catalytic activity and chemical stability, suggesting its future application in catalysis.

Discovery of Two-dimensional Hexagonal MBene HfBO and Exploration on its Potential for Lithium-Ion Storage

The practical applications of two-dimensional (2D) transition-metal borides (MBenes) have been severely hindered by the lack of accessible MBenes because of the difficulties in the selective etching of traditional ternary MAB phases with orthorhombic symmetry (ort-MAB). Here, we discover a family of ternary hexagonal MAB (h-MAB) phases and 2D hexagonal MBenes (h-MBenes) by ab initio predictions and experiments. Calculations suggest that the ternary h-MAB phases are more suitable precursors for MBenes than the ort-MAB phases. Based on the prediction, we report the experimental synthesis of h-MBene HfBO by selective removal of In from h-MAB Hf2 InB2 . The synthesized 2D HfBO delivered a specific capacity of 420 mAh g-1 as an anode material in lithium-ion batteries, demonstrating the potential for energy-storage applications. The discovery of this h-MBene HfBO added a new member to the growing family of 2D materials and provided opportunities for a wide range of novel applications.

[Epidemiological distribution of genotypes and sub-genotypes of hepatitis B virus in 15 ethnic groups in China]

Objective: To understand the distribution of genotypes and sub-genotypes of HBV in different ethnic groups in China. Methods: The HBsAg positive samples were selected by stratified multi-stage cluster sampling from the sample base of national HBV sero-epidemiological survey in 2020 for the amplification of S gene of HBV by nested PCR. A phylogeny tree was constructed to determine the genotypes and sub-genotypes of HBV. The distribution of genotypes and sub-genotypes of HBV were analyzed comprehensively by using laboratory data and demographic data. Results: A total of 1 539 positive samples from 15 ethnic groups were successfully amplified and analyzed, and 5 genotypes (B, C, D, I and C/D) were detected. The proportion of genotype B was higher in ethnic group of Han (74.52%, 623/836), Zhuang (49.28%, 34/69), Yi (53.19%, 25/47), Miao (94.12%, 32/34), Buyi (81.48%, 22/27). The proportions of genotype C were higher in ethnic groups of Yao (70.91%, 39/55). Genotype D was the predominant genotype in Uygur (83.78%, 31/37). Genotype C/D were detected in Tibetan (92.35%,326/353). In this study, 11 cases of genotype I were detected, 8 of which were distributed in Zhuang nationality. Except for Tibetan, sub-genotype B2 accounted for more than 80.00% in genotype B in all ethnic groups. The proportions of sub-genotype C2 were higher in 8 ethnic groups, i.e. Han, Tibetan, Yi, Uygur, Mongolian, Manchu, Hui and Miao. The proportions of sub-genotype C5 were higher in ethnic groups of Zhuang (55.56%, 15/27) and Yao (84.62%, 33/39). For genotype D, sub-genotype D3 was detected in Yi ethnic group and sub-genotype D1 was detected in both Uygur and Kazak. The proportions of sub-genotype C/D1 and C/D2 in Tibetan were 43.06% (152/353) and 49.29% (174/353). For all the 11 cases of genotype I infection, only sub-genotype I1 was detected. Conclusions: Five genotypes and 15 sub-genotypes of HBV were found in 15 ethnic groups. There were significant differences in the distribution of genotypes and sub-genotypes of HBV among different ethnic groups.

[Epidemiological distribution of hepatitis B virus genotypes in acute hepatitis B cases in China,2015-2017]

Objective: To analyze the genotype distribution of acute hepatitis B virus in China. Methods: A total of six hundred and twenty acute Hepatitis B cases reported to China Information System for Diseases Control and Prevention from 2015 to 2017 were selected. First, the full-length HBV genome was obtained by nested PCR amplification. In addition, the HBV genotype was determined by constructing a phylogeny tree. Finally, using primarydata, HBV genotype distribution was analyzed. Results: A total of 519 (83.71%, 519/620) sequences were obtained genotype of 620 acute hepatitis B cases, including A (0.19%, 1/519), B (27.17%, 141/519), C (62.04%, 322/519), D (9.06%, 47/519), I (0.77%, 4/519) and C/D (0.77%, 4/519); B2(95.03%, 134/141) and C2 (72.67%, 234/322) were the two major subgenotypes. Genotypes were distributed differently in seven regions of China. The proportion of genotype C appeared higher in Northeast China (94.55%, 52/55), North China (93.85%, 61/65), East China (78.87%, 56/71), and South China (58.14%, 50/86). The proportion of genotype B was higher in Central China (58.07%, 36/62) and Southwest China (52.94%, 45/85), the proportion of genotype D was the highest in Northwest China (48.42%, 46/95). A total of 515 cases were classified as serotypes, including 'adr' (57.48%, 296/515), 'adw' (30.87%, 159/515), 'ayr' (0.19%, 1/515), and 'ayw' (11.46%, 59/515). Genotype B was dominated by 'adw' serotype (92.14%, 129/140), genotype C was dominated by 'adr' serotype (91.88%, 294/320),all genotype D were 'ayw' serotype. The genotype of acute hepatitis B was correlated with serotype, 'adw' was dominant in genotype B, 'adr' was dominant in genotype C and 'ayw' was dominant in genotype D.In different gender and age group, there was no statistical significance ingenotype distribution (P>0.05). Conclusions: The genotype of acute hepatitis B in China from 2015 to 2017 was mainly B, C, and D; genotype C was dominant in the Northeast China,North China, East China and South China; B and C were common in Central and Southwest China, and genotype B was dominant. Genotype D was primarily distributed in Northwest China. The genotype of acute hepatitis B was correlated with serotype, 'adw' was dominant in genotype B, 'adr' was dominant in genotype C and 'ayw' was dominant in genotype D. There was no difference in the distribution of acute hepatitis B genotypes among different genders and age groups.

[Self-awareness rate and its influencing factors of their infection status among hepatitis B surface antigen-positive persons aged 15-69 years in China]

Objectives: To understand the awareness rate and its influencing factors of their HBV infection status among HBsAg-positive persons aged 15-69 years in China. Methods: A cross-sectional design was used to conduct a questionnaire survey on the awareness of their infection status among HBsAg-positive persons aged 15-69 years who were identified in the 2020 national hepatitis B seroepidemiology survey. The awareness rate of the whole respondent and respondents with different characteristics were described, and the differences were compared with the χ² test. The logistic regression model was used to analyze the factors influencing the awareness rate. Results: The overall awareness rate among the respondents was 43.10% (1 828/4 241). The awareness rate was lower in males than in females (41.30% vs. 44.65%). The awareness rate was lower in the 60-69-years-old age group than in other age groups (30.38% vs. 36.77%-57.58%). The awareness rate was lower in rural areas than in urban areas (39.43% vs. 47.32%). The awareness rate was lower in regions with a per capita gross domestic product (GDP) below RMB 54 000 than in regions with a per capita GDP of RMB 54 000 and above (36.81% vs. 41.61%-50.30%). The awareness rate was lower in respondents without other liver diseases than with other liver diseases (41.52% vs. 60.68%). The awareness rate was lower in respondents without a family history of hepatitis B-related disease or unknown family history than with a family history (43.58% vs. 68.26%; 24.71% vs. 68.26%). Multivariate logistic regression analysis showed that male [odds ratio (OR)=0.841, 95% confidence interval (CI): 0.734-0.964], high school and below [primary school and below, junior middle school, high school/technical secondary school, OR (95%CI): 0.247 (0.190-0.321), 0.451 (0.352-0.577), 0.634 (0.486-0.827)], rural areas (OR=0.822, 95%CI: 0.715-0.945) and regions with a per capita GDP below RMB 80 000 [54 000-80 000, OR (95%CI): 0.810 (0.688-0.954), below RMB 54 000, OR (95%CI): 0.793 (0.669-0.941)] were the negative factors influencing the awareness rate. While 30-39-years-old (OR=2.089, 95%CI: 1.626-2.683) and 40-49-years-old (OR=1.590, 95%CI: 1.250-2.023) age groups, with other liver diseases (OR=2.244, 95%CI: 1.754-2.871) and family history related to hepatitis B (OR=2.688, 95%CI: 2.242-3.223) were the positive factors influencing the awareness rate. Conclusion: The overall awareness rate of their infection status among HBsAg-positive persons aged 15-69 years is 43.10% in China. Health promotion and coverage expansion on HBV screening should be further strengthened to achieve the proposed World Health Organization's target of 90% HBV infection diagnosis rate by 2030.

Hexagonal MBene (Hf2BO2): A Promising Platform for the Electrocatalysis of Hydrogen Evolution Reaction

Hexagonal MAB (h-MAB) phases and their two-dimensional (2-D) derivatives (h-MBenes) have emerged as promising materials since the discovery of Ti₂InB₂. Herein, we identified that a possible h-MBene, 2-D Hf₂BO₂, can be an excellent platform for the electrocatalysis of hydrogen evolution reaction (HER) by density functional theory calculations. We proposed two approaches of transition metal (TM) modifications by atom deposition and implanting to optimize the HER performance of 2-D Hf₂BO₂. It is revealed that a moderate charge reduction of surface O, which is induced by the introduction of TM atoms, is conductive to a higher catalytic performance. The synergistic effect between implanted TM atoms and Hf₂BO₂ matrix can efficiently activate the surface by broadening O-p orbitals and shifting up p-band center, especially for V, Cr, and Mo as dopants, which can reduce the Gibbs free energy (ΔG_H*) from 0.939 to -0.04, 0.05 and -0.04 eV, respectively. Interestingly, this effect works within a local region and the activity can also be evaluated by bond length of Hf-O, in addition to ΔG_H*. This work suggests that due to its excellent electrocatalysis properties, h-MBenes can open up a new area for 2-D materials and will stimulate researchers to explore the synthesis of h-MAB phases and the stripping of h-MBenes.

[Analysis on hepatitis B cases reported from surveillance points in China, 2019]

Objective: To understand the characteristics of hepatitis B cases reported through the National Notifiable Disease Reported System (NNDRS) of China in 2019, analyze the quality of hepatitis B reporting. Methods: The survey forms and reporting cards of hepatitis B cases in 200 surveillance points in China in 2019 were collected from NNDRS, the completeness rate of the reporting card was calculated, and the reported hepatitis B cases were verified based on the diagnostic criteria (WS 299-2008). The clinical types of the cases after verification were compared with the reported ones, the consistency was evaluated with Kappa test. The reasons for the inconsistent clinical types of the cases were analyzed. Results: In 2019, a total of 64 686 hepatitis B cases were reported through NNDRS. Acute, chronic and unclassified hepatitis B cases accounted for 5.8%, 92.4% and 1.8%, respectively. The average age of reported cases was 47 (47±15) years, and males accounted for 64.4%. The average level of alanine aminotransferase was 214.2 (214.2±1 253.4) U/L. The reported cases mainly worked in agriculture, forestry, animal husbandry, fishery, and water conservancy (50.6%, 32 722). The proportions of cases reported from the eastern, western and central regions were 42.5% (27 501),22.1% (14 315) and 35.4% (22 870), respectively. The consistent rate of the clinical types between the reported cases and the verified cases was 58.8%, with a Kappa value of 0.15. For the 39 271 cases confirmed as acute and chronic hepatitis B cases in the reporting cards, the consistent rate of the clinical types between the reported cases and the verified cases was 96.9%, with a Kappa value of 0.73. In 94.5% (24 267/25 681) of the cases with inconsistent clinical types, the reporting card information were incomplete. Conclusion: The diagnosis of hepatitis B has been improved in the hepatitis B surveillance in China, but it is necessary to improve the completeness of the reporting cards of hepatitis B cases to NNDRS.

[Cost-benefit analysis of the hepatitis B vaccination to prevent mother-to-child transmission strategies in China, 1992-2019]

Objective: To make a cost-benefit analysis of the hepatitis B vaccination (HepB) to prevent mother-to-child transmission (PMTCT) strategies in China, 1992-2019. Methods: We built a decision analytic-Markov model to estimate the birth cohorts of 1992-2019. The parameters in our model were referred from literature, published yearbooks, and data from Chinese Center for Disease Control and Prevention. We conducted a univariate sensitivity analysis to test the robustness of the model. Results: For the 28 birth cohorts, the Chinese government has invested 37.43 billion RMB Yuan in direct costs and 47.61 billion RMB Yuan in societal costs on HepB vaccination and HBV prevention of mother to child transmission (PMTCT). And we estimated that about 50 million chronic HBV infections and 12.5 million premature deaths due to HBV-related diseases would be averted. China would save 2.89 trillion RMB Yuan and 6.92 trillion RMB Yuan for the direct and societal medical burden on HBV-related conditions. The direct and societal net benefit was 2.85 trillion RMB yuan 6.87 trillion RMB yuan, respectively. The direct and societal benefit-cost ratios (BCRs) were 77.21 and 145.29, respectively. Conclusion: The strategies of HepB vaccination for HBV PMTCT prevention were cost-effective in China during 1992-2019.

[Estimation of incidence of viral hepatitis B and analysis on case characteristics in China,2013-2020]

Objective: To understand the epidemiological characteristics of hepatitis B in China, evaluate the performance of elimination hepatitis B in China and provide scientific evidence for the prevention and control of hepatitis B. Methods: An analysis was conducted by using the data of hepatitis B cases reported to the National Notifiable Disease Reporting System (NNDRS) from the areas with low, moderate and high hepatitis B prevalence in China from 2013 to 2020, and the information about the diagnoses of the hepatitis B cases were collected, the incidence of hepatitis B was estimated according to the reporting and diagnosis information and the characteristics of acute and chronic hepatitis B were compared. Results: A total of 27 013 hepatitis B cases were reported to NNDRS, including 4 070 acute cases, 21 971 chronic cases and 972 unclassified cases. Among the reported acute hepatitis B cases, 69.9% (2 845/4 070) were confirmed. Among the reported chronic hepatitis B cases, 89.0% (19 548/21 971) were confirmed, and 2.1% (452/21 971) were confirmed as acute cases. It was estimated that the incidence of acute hepatitis B was 4.6/100 000 and the incidence of chronic hepatitis B cases was 54.5/100 000. The case number of acute hepatitis B in age group 31-45 years was highest, accounting for 35.3% (1 164/3 297). The case number of acute hepatitis B in children under 15 years old was lowest, accounting for 0.4% (13/3 297). The case number of chronic hepatitis B in age group 46-60 years was highest, accounting for 34.4% (7 211/20 932). Conclusions: The incidence of acute hepatitis B was in decrease and the incidence of chronic of hepatitis B was in increase in China year by year. It is important to strengthen the standardized diagnosis and treatment of chronic hepatitis B to decrease the morbidity and mortality of hepatitis B. At the same time, it is necessary to standardize the management and reporting of hepatitis B cases reported to NNDRS to improve the accuracy of the reporting of hepatitis B.

Theoretical exploration of quaternary hexagonal MAB phases and two-dimensional derivatives

The newly discovered hexagonal MAB (h-MAB) phases have shown great promise in synthesizing 2-D borides, but wide application is hindered by the limited kinds of transition metals that can be involved. In this work, an extensive structure search was performed to identify stable quaternary h-MAB phases by alloying ternary h-MAB phases with a fourth component. The predicted 22 stable quaternary h-MAB phases reveal that there is plenty of room for further exploration of new materials by element alloying. Moreover, we theoretically proved the possibility of exfoliating h-MBenes from the predicted quaternary phases through the selective removal of A components. The simulations for the hydrogen evolution reaction (HER) revealed that the bi-metal combination demonstrates a great advantage to enrich the application perspectives of h-MBenes. The discovery of quaternary h-MAB phases and two-dimensional derivatives offers new insights and understanding of boride-based materials.

Correction: Discovery of intrinsic two-dimensional antiferromagnets from transition-metal borides

Correction for 'Discovery of intrinsic two-dimensional antiferromagnets from transition-metal borides' by Shiyao Wang et al., Nanoscale, 2021, 13, 8254-8263, DOI: 10.1039/D1NR01103K.

Discovery of intrinsic two-dimensional antiferromagnets from transition-metal borides

Intrinsic two-dimensional (2D) magnets are promising materials for developing advanced spintronic devices. A few have already been synthesized from the exfoliation of van der Waals magnetic materials. In this work, by using ab initio calculations and Monte Carlo simulation, a series of 2D MBs (M = Cr, Mn or Fe; B = boron) are predicted possessing robust magnetism, sizeable magnetic anisotropy energy, and excellent structural stability. These 2D MBs can be respectively synthesized from non-van der Waals compounds with low separation energies such as Cr2AlB2, Mn2AlB2, and Fe2AlB2. 2D CrB is a ferromagnetic (FM) metal with a weak in-plane magnetic anisotropy energy of 23.6 μeV per atom. Metallic 2D MnB and FeB are Ising antiferromagnets with an out-of-plane magnetic easy axis and robust magnetic anisotropy energies up to 222.7 and 482.2 μeV per atom, respectively. By using Monte Carlo simulation, the critical temperatures of 2D CrB, MnB, and FeB were calculated to be 440 K, 300 K, and 320 K, respectively. Our study found that the super-exchange interaction plays the dominant role in determining the long-range magnetic ordering of 2D MBs. Moreover, most functionalized 2D MBTs (T = O, OH or F) are predicted to have AFM ground states. Alternating transition metals or functional groups can significantly modulate the magnetic ground state and critical temperature of 2D MBTs. This study suggests that the 2D MBs and MBTs are promising metallic 2D magnets for spintronic applications.

Exploring structural, electronic, and mechanical properties of 2D hexagonal MBenes

A family of two-dimensional (2D) transition metal borides, referred to as MBenes, is recently emerging as novel materials with great potentials in electronic and energy harvesting applications to the field of materials science and technology. Transition metal borides can be synthesized from chemical exfoliation of ternary-layered transition metal borides, known as MAB phases. Previously it has been predicted that thin pristine 2D Sc-, Ti-, Zr-, Hf-, V-, Nb-, Ta-, Mo-, and W-based transition metal borides with hexagonal phase are more stable than their corresponding orthorhombic phase. Here, using a set of first-principles calculations (at absolute zero temperature), we have examined the geometric, dynamic stability, electronic structures, work function, bond strength, and mechanical properties of the hexagonal monolayer of transition metal borides (M= Sc, Ti, Zr, Hf, V, Nb, Ta, Mo, and W) chemically terminated with F, O, and OH. The results of the formation energies of terminated structures imply that the surface terminations could make a strong bond to the surface transition metals and provide the possibility of the development of transition metal borides with those surface terminations. Except for ScBO, which is an indirect bandgap semiconductor, the other transition metal borides are metallic or semimetal. Particularly, TiBF, ZrBF, and HfBF are metallic systems whose band dispersions close to the Fermi level indicate the coexistence of type-I and type-II nodal lines. Our calculated work functions indicate that 2D transition metal borides with OH (O) functionalization obtain the lowest (highest) work functions. The results of the mechanical properties of the considered structures imply that oxygen functionalized transition metal borides exhibit the stiffest mechanical strength with 248 <E(N m^-1) < 348 while non-terminated transition metal borides are generally the weakest systems with 206 <E(N m^-1) < 283.

[Epidemiological analysis of viral hepatitis E in China, 2004-2017]

Objective: To analyze the changing epidemiological characteristics of hepatitis E cases in China, in order to promote in preventing and controlling hepatitis E. Methods: Data of hepatitis E and outbreaks reported through national notifiable diseases reporting system were analyzed from 2004 to 2017, but data of Hongkong, Macau and Taiwan were not included. Data of hepatitis E were divided into three phases as 2004-2007, 2008-2011 and 2012-2017, representing eight years before, four years before and years after the postmarketing of hepatitis E vaccine. Linear regression was used for analyzing the trend of hepatitis E, improved muster method was used for analyzing the seasonal intensity. Results: From 2004 to 2017, 329 519 hepatitis E cases were reported and the annual incidence were increasing from 1.27/100 000 to 2.10/100 000 (t=6.87, P<0.001). The concentrations of hepatitis E during 2004-2007, 2008-2011 and 2012-2017 were 17.43, 16.06, 11.17, respectively, with low seasonal intensity. Number of cases reported by Jiangsu, Guangdong and Zhejiang accounted for 31.54% of national cases. The incidence were lower in central (1.45/100 000) and western (1.11/100 000) region than that in eastern region (2.67/100 000), but were increasing continuously. There was an increasing trend of incidence with growing ages (t=7.85, P<0.001). The incidence was higher than 2/100 000 among cases aged ≥40, and was the highest (5.22/100 000) in the age group of 65-69 years old. Farmers, retired persons, houseworkers and unemployees accounted for 67.46% of total cases. A total of 7 outbreaks were reported, among which 3 were in nursing homes. Conclusion: The incidence of hepatitis E in central and western regions were increasing continuously and the surveillance should be strengthened. There was higher risk among middle-aged population, farmers and nursing homes, so strategy for immunization among those population was in great need.

Discovery of hexagonal ternary phase Ti2InB2 and its evolution to layered boride TiB

Mn+1AXn phases are a large family of compounds that have been limited, so far, to carbides and nitrides. Here we report the prediction of a compound, Ti2InB2, a stable boron-based ternary phase in the Ti-In-B system, using a computational structure search strategy. This predicted Ti2InB2 compound is successfully synthesized using a solid-state reaction route and its space group is confirmed as P[Formula: see text]m2 (No. 187), which is in fact a hexagonal subgroup of P63/mmc (No. 194), the symmetry group of conventional Mn+1AXn phases. Moreover, a strategy for the synthesis of MXenes from Mn+1AXn phases is applied, and a layered boride, TiB, is obtained by the removal of the indium layer through dealloying of the parent Ti2InB2 at high temperature under a high vacuum. We theoretically demonstrate that the TiB single layer exhibits superior potential as an anode material for Li/Na ion batteries than conventional carbide MXenes such as Ti3C2.

[A typical investigation on the status of diagnosis and reporting of hepatitis B inpatients in non-surveillance hospitals in three provinces in China, 2015]

Objective: To review the consistency of diagnosis and reporting of hepatitis B (HB) patient in non-surveillance hospitals in three provinces and analyze the influencing factors. Methods: In 2016, using typical survey methods, we carried out a hospital-based pilot study in three provinces: Fujian, Hainan and Gansu. In each province, we chose two hospitals with grade 3 and grade 2 respectively in each province, using the following criteria: (1) in 2015, the hospital reported a greater number of hepatitis B cases compared the hospital-based provincial mean; (2) the hospital had an advanced laboratory information system (LIS) with access to HBsAg test results; (3) the hospital had an electronic hospital information system (HIS) which linked to the LIS via the inpatient medical record number; (4) general hospital; (5) non-surveillance hospitals for hepatitis B. Using national notifiable infectious disease reporting system (NNDRS), we chose all HB patients who were reported by the investigated hospitals in 2015, and we linked NNDRS HBV case-reports with patient-data from hospital information systems (HIS) to review the diagnosis, and then to compare the consistency of reviewed diagnosis and NNDRS report diagnosis, which we made a descriptive analysis. We used multivariable logistic regression to examine factors associated with misclassification of case-reports to NNDRS. Results: We found the NNDRS report accuracy was 47.11% (669) among 1 420 eligible inpatient hepatitis B inpatients. Of the 352 reported acute HBV cases, 6.53% (23) were consistent with our medical record review, the accuracy rate for level 2 hospitals and level 3 hospitals was 9.42% (21) and 1.55% (2), respectively. Of the1 068 reported chronic HBV cases, 60.49% (646) were consistent with our medical record review, the accuracy rate for level 2 hospitals and level 3 hospitals was 57.92% (106) and 60.02% (540), respectively. Compared to primary diagnosis of HB patients, the OR(95%CI) for mis-report was 29.36 (19.21-44.76) in non-primary diagnosis of HB patients. Compared to Fujian Province, the mis-report risk was higher in Hainan province and Gansu Province, with the values of OR (95%CI) being 2.33 (1.58-3.44) and 20.38 (11.29-36.78), respectively; compared to level 3 hospitals, the OR (95%CI) for mis-report was 2.38 (1.66-3.42) for level 2 hospitals; compared to HB related wards, the OR (95%CI) for mis-report was 1.45 (1.04-2.01) in non-HB-related wards. Conclusion: In some non-surveillance areas of China, the consistency between hepatitis B diagnosed in hospital and reported in NNDRS was low. Factors affecting the accuracy of HB surveillance data in NNDRS were level 2 hospitals, non-liver disease departments and nonprimary diagnosis of HB.

[The application of extracorporeal membrane oxygenation in children in China]

Objective: To investigate the application of extracorporeal membrane oxygenation (ECMO) in pediatrics in China as well as the outcomes. Methods: Data was conducted by questionnaire to investigate the use of ECMO in children under the age of 18 in China by June 30, 2017. All patients were divided into two age groups: pediatric patients (29 d-18 y) and neonates (1-28 d); Also by the causes of ECMO treating including cardiac, respiratory and extracorporeal cardiopulmonary resuscitation (ECPR). The form included the numbers of ECMO cases, weaned and discharged cases, according to the different ages and causes. In addition, the departments that routinely participate in ECMO management were acquired. Results: Totally 43 tertiary hospitals were enrolled, of which 30 have implemented ECMO for the children patients (comprising pediatrics and neonates), including 14 general hospitals, 5 cardiothoracic specialty hospitals and 11 children's or women and children's hospitals. ECMO for pediatrics and neonates was firstly carried out at mainland China in 2004. To the deadline of investigation, 800 patients were supported with ECMO, among which 658 were pediatrics, much more than 142 of neonates. As to pediatrics, 453 were supported with ECMO for cardiac indications with 287 (63.4%) weaned off and 215 (47.5%) survived to discharge; for respiratory causes, 79 cases were registered with 47 (59.5%) weaned off and 36 (45.6%) discharged; for ECPR, 126 were enrolled with 62 (49.2%) successfully weaned off and 48 (38.1%) discharged. In contrast, neonatal patients undergoing cardiac ECMO contained 79 cases, with 39 (49.4%) weaned off and 26 (32.9%) discharged; due to respiratory causes, 40 neonates were included, with 26 (65.0%) weaned off and 21 (52.5%) discharged; 23 neonatal patients consisted of ECPR cause and 10 (43.5%) of them successfully weaned off, but only 6 (26.1%) finally survived. Among the 30 hospitals conducted ECMO for pediatrics and neonates, the average number of departments for ECMO management is 4.03±1.87. Conclusions: Although ECMO used for children in mainland China is relatively late, a certain number of cases have been accumulated, and there is still a gap compared with the international standard. Meanwhile, each hospital has preliminarily built up its own ECMO team.

The epidemiology of hepatitis B virus infection in women of reproductive age in highly endemic areas in China

We describe the epidemiology of hepatitis B virus (HBV) infection among women of reproductive age residing in areas of China that are highly endemic for chronic HBV, and provide evidence useful for decision-makers to guide strategies for preventing mother-to-child transmission of HBV, and assess the impact of perinatal transmission PMTCT by projecting HBsAg prevalence trends without interventions. We conducted a cross-sectional HBV serological survey of women, 15-49 years of age, residing in Fujian, Guangdong, Guangxi and Hainan provinces. Demographic and other subject-level data were collected in face-to-face interviews, after which we obtain blood specimens. Specimens were tested for HBV sero-markers by ELISA (Beijing Wantai Biological Pharmacy), and HBV DNA was tested with PCR (Hunan Sansure Biotech). Weighted HBsAg and HBV (either HBsAg+ or anti-HBc+ indicating either present or past infection) prevalences were 11.82% and 57.16%, respectively. Among the HBsAg-positive women, 27% were also HBeAg positive. The proportion of individuals with HBV DNA loads >10⁵ IU/mL declined with increasing age. Among HBsAg-negative women, 0.9% had occult HBV infection. The prevalence of chronic HBV infection among reproductive women in these highly endemic provinces is high, posing a threat to maternal health and risk of mother-to-child transmission. Prevention of mother-to-child transmission remains critically important.

[Epidemiological analysis of viral hepatitis A in China, 2004-2015]

Objective: To analyze the epidemiological characteristics of hepatitis A cases in China from 2004 to 2015. Methods: Data of hepatitis A were reported through national notifiable disease information reporting system, which covered the 31 provinces (Hong Kong, Macau and Taiwan excluded). The inclusion criteria was: date of illness onset was between January 1(st) 2004 and December 31(st) 2015, the status of reported card was confirmed, the case was classified as laboratory confirmed or clinical diagnosed, the disease was Hepatitis A. The information such as sex, date of birth, date of illness onset, place of residence was collected. The data was divided into three phases, 2004-2007, 2008-2011, 2012-2015, which represented the phase before expanded program on immunization (EPI), first 4 years after EPI, second 4 years after EPI. Results: From 2004 to 2015, there were totally 574 697 hepatitis A cases in China, the mean annual incidence was 3.62/100 000. The risk ratio of hepatitis A in 2015 was 0.23 when compared with 2004. Sichuan, Xinjiang and Yunnan contributed to 27.27% of the total cases in China. In 2012-2015, the incidence of western (3.46/100 000) region was significantly higher than that in central (1.21/100 000) and eastern (1.08/100 000) regions. From 2004-2015, number of cases in each age group declined greatly, with number of cases declining from 43 711 to 5 938 in the age group of 5-9 years, from 29 722 to 3 438 in 10-14, from 23 212 to 3 646 in 15-19. The number of cases declined from 24 079 to 10 304 in the age group of 0-4 (declined by 57.21%), but in 2012-2015, the incidence of 0-4 age group was still the highest, with 77.72% cases in Xinjiang and Sichuan. Famers, students and scattered children accounted for 69.95% of total cases, with student cases declined from 24.08% (2004-2007) to 8.67% (2012-2015). Conclusion: The incidence of hepatitis A in China is decreasing year by year, the risk has been decreasing to a relatively low level. However, in western regions and children under age five, the risk is still high. Precision intervention is needed for further prevention and control of hepatitis A.

[Comparative analyze on hepatitis B seroepidemiological surveys among population aged 1-29 years in different epidemic regions of China in 1992 and 2014]

Objective: To evaluate the effect of hepatitis B prevention and control by comparative analysis on the results of HBsAg, anti-HBs and anti-HBc prevalence from national hepatitis B seroepidemiological surveys in 1992 and 2014 in different epidemic regions of China. Methods: Data was from the national seroepidemiological surveys of hepatitis B conducted in 1992 and 2014. The survey in 1992 was conducted in 145 disease surveillance points of 30 provinces (excluding Hong Kong, Macao Special Administrative Region and Taiwan province) in China. The survey in 2016 was conducted in 160 disease surveillance points of 31 provinces (excluding Hong Kong, Macao Special Administrative Region and Taiwan province) in China. In the two surveys, face-to-face interviews with the subject by door to door or on the investigation site were conducted by trained staff using standard questionnaires to obtain basic information including birth date, gender, ethnicity, resident place and so on. And then 5 ml venous blood was collected to test the sero-markers of HBsAg, anti-HBs and anti-HBc. We analyzed unweighted point prevalence and 95% CI of HBsAg, anti-HBs and anti-HBc in 1992 which had no design weighting, and analyzed weighted point prevalence and 95%CI of HBsAg, anti-HBs and anti-HBc in 2014 which had design weighting. Results: 34 291 and 31 713 people aged 1-29 years were involved in 1992 and 2014 national serosurveys of China, respectively. For the people aged 1-29 years, HBsAg prevalence was 2.64% (95%CI: 2.28%-3.06%) in 2014 and decreased by 73.92% as compared with the rate 10.13% (95% CI: 9.81%-10.45%) in 1992. Anti-HBc prevalence was 13.01% (95%CI: 12.09%-14.00%) in 2014 and decreased by 71.61% as compared with the rate 45.84% (95% CI: 45.31%-46.37%) in 1992. Anti-HBs prevalence was 57.79% (95%CI: 56.33%-59.25%) in 2014 and ascended by 127.41% as compared with the rate 25.41% (95% CI: 24.95%-25.87%) in 1992. In high, medium and low epidemic region, for the people who born during 1992-2001 when hepatitis B vaccine was introduced in routine immunization management, HBsAg prevalence was 4.74% (95%CI: 3.79%-5.69%), 1.59% (95%CI: 1.09%-2.10%) and 2.53% (95%CI: 1.66%-3.39%), respectively, and anti-HBs prevalence was 64.25% (95% CI: 62.11%-66.39%), 56.34% (95% CI: 54.50%-58.57%), 54.49% (95%CI: 51.75%-57.23%), respectively, and anti-HBc prevalence was 15.16% (95%CI: 13.56%-16.76%), 11.07% (95%CI: 9.80%-12.33%), 7.61% (95%CI: 6.15%-9.07%), respectively. In high, medium and low epidemic region, for the people who born during 2002-2013 the duration which hepatitis B vaccine was integrated in expanded immunization program born during when HBsAg prevalence was 0.88% (95%CI: 0.66%-1.11%), 0.37% (95%CI: 0.24%-0.49%)and 0.71% (95%CI: 0.48%-0.94%), respectively, and anti-HBs prevalence was 60.74% (95%CI: 59.57%-61.90%), 59.46% (95%CI: 58.44%-60.49%), 52.56% (95% CI: 51.20%-53.92%), respectively, and anti-HBc prevalence was 3.30% (95% CI: 2.87%-3.72%), 1.91% (95%CI: 1.63%-2.20%), 2.25% (95%CI: 1.85%-2.66%), respectively. Conclusion: China had made great achievement in hepatitis B prevention and control. HBsAg prevalence among people aged 1-29 years old in 2014 decreased dramatically as compared with that in 1992. Since hepatitis B vaccine was integrated into expanded immunization program, China reduced HBsAg prevalence to less than 1% among people aged 1-12 years in 2014 in different epidemic region.

[Potential mechanism and prognostic value of promoter methylation of PRDM1 gene in diffuse large B cell lymphoma]

Objective: To investigate PRDM1 gene methylation status, immune classification and their prognostic significance in diffuse large B cell lymphoma (DLBCL). Methods: Immunohistochemical (IHC) staining for CD20, CD10, bcl-2, bcl-6, PRDM1/Blimp-1 and MUM1 was carried out in 100 cases of DLBCL specimens and 20 reactive lymphoid proliferation samples. All patients were classified into germinal center B cell-like (GCB) and activated B cell-like (ABC) subtype according to Hans' algorithmin. PRDM1 gene methylation was detected by methylation-specific PCR (MSP) and its relationship with clinicopathologic parameters was analyzed. OCI-Ly1 (GCB type) and OCI-Ly3 (ABC type) cell lines were transfected by Small interfering RNA(siRNA) with cationic lipid reagent transfection mediated, and the PRDM1/Blimp-1 expression in before and after transfected cell lines were detected with reverse transcription-PCR and Western blot methods. The relationship between PRDM1 gene methylation, clinicopathologic parameter and survival was analyzed using one-way analysis of variance. Results: One hundred patients were classified into 73 (73%) cases of GCB subtypes and 27 (27%) cases of ABC. PRDM1/Blimp-1 was expressed in 21 DLBCL and highly expressed in 20 reactive lymphoid proliferation. PRDM1 gene methylation was detected in 23% (23/100) of DLBCL, while no methylation was detected in all 20 reactive lymphoid proliferation. The difference of the PRDM1 methylation status between DLBCL and the control samples was statistically significant (P=0.004). However, there was no significant correlation between the PRDM1 gene methylation and clinicopathologic parameters (P>0.05). Reverse transcription-PCR and Western blot showed that PRDM1 gene expression was reduced in siRNA-induced group compared with blank control group and negative control group. One-way analysis of variance revealed that aged ≥60 years, performance status score above 3, and the presence of general symptoms were associated with significantly lower overall survival rate. Conclusions: PRDM1 gene silencing with aberrant CpG methylation is probably one of the critical events in the oncogenesis of DLBCL. This may have important implications as a candidate marker for diagnosis and targeted gene therapy. Meanwhile in vitro siRNA transfected OCI-Ly1 and OCI-Ly3 cell lines confirm that PRDM1 gene is a suppressor gene in DLBCL and may represent a novel therapeutic target.

[Consistency analysis on acute hepatitis B inpatients reported by hepatitis B surveillance pilot spots in six provinces of China]

Objective: To understand the characteristics of acute hepatitis B inpatients reported by the hepatitis B surveillance pilot points and to estimate the consistency between the diagnosed and reported types of hepatitis B by the clinicians involved. Methods: Data related to acute hepatitis B was from the NNDRS and the characteristics of acute hepatitis B were classified by querying Hospital Information System. We recorded the results based on clinical diagnosis and analyzed the consistency between the reported and diagnosed types that the clinicians made, on hepatitis B. Results: A total of 179 patients were included in this study with all of them as acute hepatitis B reported through NNDRS in 2015-2016. In terms of the durations of disease, among the 179 cases who were HBsAg positive, 32.40% (58/179) of them exceeding 6 months, 2.79% (5/179) within 6 months and 64.80% (116/179) tested the first time or never. Among the 179 cases who claimed having the history of hepatitis, 33.52% (60/179) of them identified as having hepatitis B, 1.12% (2/179) were hepatitis A, C or E, 41.34% (74/179) did not have the signs on hepatitis, while the rest 24.02% (43/179) did not know the situation. Only 79.89% (143/179) of the patients showed the symptoms or signs of hepatitis, but the rest 20.11% (36/179) did not. Among the 179 reported acute hepatitis patients, 67 of them were diagnosed as acute hepatitis B while 112 cases were as non-acute hepatitis B. The consistent rate of acute hepatitis B was 37.43% (67/179). Among the 112 cases that were diagnosed as non-acute hepatitis B, proportions of chronic hepatitis B and cirrhosis were 49.11%(55/112) and 16.07%(18/112) respectively. Conclusion: Consistency between the reported type of acute hepatitis B inpatients and the types diagnosed by clinicians was poor. Our results suggested that clinicians should make the accurate diagnosis at first place and then report to the Network in accordance with the clinical diagnosis classification criterfia, set by the government.

[Epidemiological characteristics of children aged 1-4 years without timely birth dose of hepatitis B vaccine vaccination in China, 2014]

Objective: To evaluate the epidemiological characteristics of the children aged 1-4 years without timely birth dose of hepatitis B vaccine (HepB(1)) vaccination. Methods: Based on the data from 160 disease surveillance points in 31 provinces of China, two-stage cluster random sampling was used to select the target population aged 1-4 years. A standard questionnaire was used to collect the information about the birth date, gender, ethnic group, place of birth, HepB immunization history of the children selected. A blood sample (3 ml) was taken from each subject for HBsAg testing. SAS software (Version 9.4) was used in our study. We analyzed the age, gender, ethnic group, area specific distributions of the children aged 1-4 years without timely HepB(1) vaccination and the influencing factors, and the relationship between the HepB(1) vaccination time and HBsAg prevalence rate. Results: A total of 12 587 children aged 1-4 years were analyzed and the non-timely HepB(1) vaccination rate was 10.12%. The place of birth, ethnic group, urban/rural area, eastern/central/western area, age were the main influencing factor of the non-timely HepB(1) vaccination. The non-timely HepB(1) vaccination rate was higher in 3-4 years old children (11.13%) than in 1-2 years old children (8.97%), in rural area (12.05%) than in urban area (8.19%), in western area (13.41%) than in central area (9.27%) and eastern area (7.72%), in minority ethnic group (18.06%) than in Han ethnic group (8.77%) and in children born outside hospital (57.66%) than in children born in hospital (9.27%). The HBsAg prevalence rate among 1-4 years children was 0.31%. The HBsAg prevalence rate of the children with timely HepB(1) vaccination (0.25%) was lower than that of the children without timely HepB(1) vaccination (0.89%). Conclusions: In China, the HBsAg prevalence rate among 1-4 years children with HepB vaccination decreased to <0.5% and the timely HepB(1) vaccination rate reached to 90%. We should strengthen the timely HepB(1) vaccination for the children in minority ethnic groups, in western area, in rural area as well as those born outside hospitals.

Comparison between the EQ-5D-5L and the EQ-5D-3L in patients with hepatitis B

OBJECTIVES

The purpose of the study was to compare psychometric properties of the EQ-5D-5L (5L) and the EQ-5D-3L (3L) health outcomes assessment instruments in patients with hepatitis B in China.

METHODS

Patients, including hepatitis B virus carriers and those with active or inactive chronic hepatitis B, compensated cirrhosis, decompensated cirrhosis or hepatocellular carcinoma, answered a questionnaire composed of 5L, socio-demographic information, 3L, and the visual analog scale (VAS), respectively. After 1 week, a retest was conducted for inpatients. We compared acceptability, face validity, redistribution properties, convergent validity, known-group validity, discriminatory power, ceiling effect, test-retest reliability, and responsiveness of 5L and 3L.

RESULTS

A total of 369 outpatients and 276 inpatients were recruited for the first interview. Of the inpatients, 183 were used in the retest. Most patients preferred 5L-3L. The 3L-5L response pairs had an inconsistency rate of 2.4%. Correlation with the VAS was greater with 5L than with 3L. Age, education, and comorbidity were associated with health-related quality of life (HRQoL). 5L discriminated more infectious conditions than 3L. In all dimensions, the Shannon's index from 5L was larger while in three dimensions the Shannon's evenness index from 5L was slightly larger. The ceiling effect was reduced in 5L. In patients with stable health states, no significant difference was detected in the weighted kappa between 5L and 3L, but intraclass correlation coefficient of 5L was higher than that of 3L. In patients with improved health states, HRQoL was seen as increased in both 5L and 3L, without significant difference.

CONCLUSIONS

The EQ-5D-5L was more suitable than the EQ-5D-3L in the patients with hepatitis B in China.

Isolation and expression of PASK, a serine/threonine kinase, during rat embryonic development, with special emphasis on the pancreas

We report the isolation and characterization of a serine/threonine kinase expressed during rat pancreas development. This kinase was cloned as part of a general screen using degenerate oligonucleotides to map expression of kinases and receptors during the course of pancreatic development. Sequence analysis showed it to be a member of the ste20-like serine/threonine kinase family. Northern blotting analysis against both fetal and adult tissues showed two transcripts, one of 2 kb and the other of 4 kb. The ratio of transcript expression varied with the tissue. In situ hybridization analysis showed that this gene is expressed in the early gut and pancreatic epithelium. By embryonic Day 15, the transcript is localized to cells that will eventually become exocrine in nature. In situ hybridization analysis also demonstrated high levels of expression in the choroid plexus, the developing myocardium, kidney, CNS, dorsal root ganglia, and testes. In addition, a search of the EST database revealed a related human kinase not previously described.

Thiopental and methohexital depress Ca2+ entry into and glutamate release from cultured neurons

BACKGROUND

Although barbiturates activate alpha-aminobutyric acid type A receptors as part of their hypnotic effect, these drugs also inhibit voltage-gated calcium channels. The authors determined if barbiturates could decrease neuronal intracellular Ca2+ transients and the resulting glutamate release.

METHODS

Neonatal rat cerebellar granule neurons were isolated and cultured on coverslips and studied at 37 degrees C. Spectrofluorometric assays were used during identical conditions to monitor intracellular Ca2+ with the Ca2+ -sensitive fluorophore fura-2 and glutamate release by a glutamate dehydrogenase-coupled assay, which produced the reduced form of nicotinamide-adenine dinucleotide phosphate in proportion to the amount of glutamate released. Neurons were depolarized by a rapid increase in external [K+] from 5 to 55 mM. Control responses were compared with those in the presence of 10, 30, and 100 microM thiopental; 3, 10, and 30 microM methohexital; decreased external [Ca2+]; or voltage-gated calcium channel blockers.

RESULTS

Thiopental and methohexital depressed the intracellular Ca2+ transient peak and plateau in a dose-dependent manner, as did decreased Ca2+. The intermediate dose of either drug caused approximately 50% decrease in peak intracellular Ca2+ and 60% decrease in glutamate release. In the presence of specific L- and/or N-type voltage-gated calcium channel blockade by nicardipine or omega-conotoxin-GVIA, respectively, 30 microM thiopental further decreased the intracellular Ca2+ transient. Thiopental caused a dose-dependent decrease in glutamate release, which was proportional to the decreased peak intracellular Ca2+.

CONCLUSIONS

Thiopental and methohexital depress the depolarization-induced increase in intracellular Ca2+ and the accompanying glutamate release, actions which can contribute to the anesthetic and neuronal protective effects of these drugs.

Sonic hedgehog promotes the survival of specific CNS neuron populations and protects these cells from toxic insult In vitro

Sonic hedgehog (Shh), an axis-determining secreted protein, is expressed during early vertebrate embryogenesis in the notochord and ventral neural tube. In this site it plays a role in the phenotypic specification of ventral neurons along the length of the CNS. For example, Shh induces the differentiation of motor neurons in the spinal cord and dopaminergic neurons in the midbrain. Shh expression, however, persists beyond this induction period, and we have asked whether the protein shows novel activities beyond phenotype specification. Using cultures derived from embryonic day 14.5 (E14. 5) rat ventral mesencephalon, we show that Shh is also trophic for dopaminergic neurons. Interestingly, Shh not only promotes dopaminergic neuron survival, but also promotes the survival of midbrain GABA-immunoreactive (GABA-ir) neurons. In cultures derived from the E15-16 striatum, Shh promotes the survival of GABA-ir interneurons to the exclusion of any other cell type. Cultures derived from E15-16 ventral spinal cord reveal that Shh is again trophic for interneurons, many of which are GABA-ir and some of which express the Lim-1/2 nuclear marker, but it does not appear to support motorneuron survival. Shh does not support the survival of sympathetic or dorsal root ganglion neurons. Finally, using the midbrain cultures, we show that in the presence of MPP+, a highly specific neurotoxin, Shh prevents dopaminergic neuron death that normally would have occurred. Thus Shh may have therapeutic value as a protective agent in neurodegenerative disease.

Volatile anesthetics affect calcium mobilization in bovine endothelial cells

BACKGROUND

The site where volatile anesthetics inhibit endothelium-dependent, nitric oxide-mediated vasodilation is unclear. To determine whether anesthetics could limit endothelium-dependent nitric oxide production by inhibiting receptor-mediated increases in cytosolic Ca2+, experiments were performed to see if the inhalational anesthetics halothane, isoflurane, and enflurane affect intracellular Ca2+ ([Ca2+]i) transients induced by the agonists bradykinin and adenosine triphosphate in cultured bovine aortic endothelial cells.

METHODS

Bovine aortic endothelial cells, which had been loaded with the fluorescent Ca2+ indicator Fura-2, were added to medium preequilibrated with volatile anesthetic (1.25% and 2.5% for isoflurane, 1.755 and 3.5% for enflurane, and 0.75% and 1.5% for halothane). In Ca(2+)-containing medium, intracellular Ca2+ transients were elicited in response to bradykinin (10 nM and 1 microM) or adenosine triphosphate (1 microM and 100 microM).

RESULTS

Both bradykinin and adenosine triphosphate triggered a rapid rise to peak [Ca2+]i followed by a gradual decline to a plateau above the resting level. Although basal [Ca2+]i was unaltered by the anesthetics, both halothane and enflurane, in a dose-dependent manner, depressed the peak and plateau of the [Ca2+]i transient elicited by 10 nM bradykinin, whereas isoflurane had no effect. When [Ca2+]i transients were elicited by 1 microM bradykinin, halothane (1% and 5%) did not alter peak and plateau levels. Halothane and enflurane also decreased [Ca2+]i transients evoked by 1 microM and 100 microM adenosine triphosphate, whereas isoflurane also had no effect in this setting.

CONCLUSIONS

Halothane and enflurane, but not isoflurane, inhibit bradykinin- and adenosine triphosphate-stimulated Ca2+ transients in endothelial cells. Limitations of Ca2+ availability to activate constitutive endothelial nitric oxide synthase could allow for part, but not all, of the inhibition of endothelium-dependent nitric oxide-mediated vasodilation by inhalational anesthetics.

[The Selaginella tamariscina (Beauv.) Spring complex in the treatment of experimental diabetes and its effect on blood rheology]

Experiments have revealed that in treating rats for diabetes induced by alloxan, the Selaginella tamariscina complex injection given intraperitoneally (25g/kg) for 12 days helps lower the levels of blood sugar and serum lipid peroxide, as well as increase the concentration of serum insulin. Histologic observation has shown that this injection could repair the structure of pancreatic inlet B cells injured by alloxan.

Volatile anesthetics depress Ca2+ transients and glutamate release in isolated cerebral synaptosomes

BACKGROUND

The current study was performed to determine whether volatile anesthetics may include as part of their action in the central nervous system the depression of presynaptic transmitter release by alteration in intrasynaptic [Ca2+] ([Ca2+]i).

METHODS

Guinea pig cerebrocortical synaptosomes were studied at 37 degrees C suspended in control buffer solution containing 1.3 mM external [Ca2+] ([Ca2+]e). Spectrofluorometric assays were used to monitor [Ca2+]i with the Ca(2+)-sensitive fluorophore Fura-2 and to monitor glutamate release with an enzyme-coupled assay that produced the fluorescent product nicotinamide adenine dinucleotide phosphate. To activate the increase in [Ca2+]i and glutamate release, synaptosomes were depolarized by abruptly increasing external [K+] from 5 to 35 mM. Responses were determined in solutions equilibrated with approximately 1 or 2 minimum alveolar concentration (MAC) isoflurane, enflurane, or halothane and also in solutions with decreased [Ca2+]e (0.025, 0.05, 0.1, 0.2, 0.4, and 0.6 mM).

RESULTS

Although they had no action on basal behavior, the anesthetics depressed the K(+)-depolarization-induced increase in both [Ca2+]i and glutamate release in a dose-dependent fashion. The [Ca2+]i transient was inhibited by 13-21% per MAC, and glutamate release was depressed 14-28% per MAC. The depression of both [Ca2+]i and glutamate release caused by 2.5% isoflurane, 3.4% enflurane, and 1.5% halothane could be reproduced by a reduction in [Ca2+]e to 0.2-0.4 mM.

CONCLUSIONS

In this setting, isoflurane, enflurane, and halothane decrease [Ca2+]i in a manner consistent with inhibition of Ca2+ entry, possibly by specific voltage-gated neuronal Ca2+ channels. This decrease in [Ca2+]i is sufficient to account for all or most of the associated decrease in glutamate release.

Effect of temperature on volatile anesthetic depression of myocardial contractions

Anesthetics are studied and used under conditions of hypothermia both experimentally and clinically. To determine if myocardial contractile depression by anesthetics is equivalent at different temperatures, depressant effects on guinea pig papillary muscle contractions were compared at 37 degrees C vs 30 degrees C. Stimulation after rest and at rates from 0.1 to 3 Hz was used. After control measurements were established at one temperature, effects due to equi-anesthetic concentrations (equivalent to approximately 0.9 minimum alveolar concentration) of halothane, isoflurane, or enflurane were determined, followed by recovery measurements. The same procedure was then applied at the other temperature. Hypothermia itself had positive inotropic effects: contractions at 30 degrees C developed about twice the tension as at 37 degrees C; the maximum rate of tension development (dT/dt-max) at 30 degrees C was about 50% greater than at 37 degrees C (1-3 Hz stimulation). When anesthetic contractile depression was assessed by the fractional decrease in dT/dt-max, the anesthetics were more depressant at 30 degrees C than at 37 degrees C, an effect which was most prominent at 0.5 Hz. In contrast to the anesthetics, 1 microM ryanodine which decreases sarcoplasmic reticulum (SR) Ca2+ release, and 0.1 microM nifedipine which decreases Ca2+ entry, both depressed dT/dt-max less at 30 degrees C than at 37 degrees C. Furthermore, ryanodine, nifedipine, and a decrease in external [Ca2+] all exhibited distinct rate-dependent contractile depression at 37 degrees C (typically greatest at 2-3 Hz) not seen with anesthetics.(ABSTRACT TRUNCATED AT 250 WORDS)