[Clinical characteristics and prognosis of 28 cases of infant acute lymphoblastic leukemia]

Objective: To analyze the clinical characteristics and prognosis of patients with infant acute lymphoblastic leukemia (IALL). Methods: A retrospective cohort study.Clinical data, treatment and prognosis of 28 cases of IALL who have been treated at Beijing Children's Hospital, Capital Medical University and Baoding Children's Hospital from October 2013 to May 2023 were analyzed retrospectively. Based on the results of fluorescence in situ hybridization (FISH), all patients were divided into KMT2A gene rearrangement (KMT2A-R) positive group and KMT2A-R negative group. The prognosis of two groups were compared. Kaplan-Meier method and Log-Rank test were used to analyze the survival of the patients. Results: Among 28 cases of IALL, there were 10 males and 18 females, with the onset age of 10.9 (9.4,11.8) months. In terms of immune classification, 25 cases were B-ALL (89%), while the remaining 3 cases were T-ALL (11%). Most infant B-ALL showed pro-B lymphocyte phenotype (16/25,64%). A total of 22 cases (79%) obtained chromosome karyotype results, of which 7 were normal karyotypes, no complex karyotypes and 15 were abnormal karyotypes were found. Among abnormal karyotypes, there were 4 cases of t (9; 11), 2 cases of t (4; 11), 2 cases of t (11; 19), 1 case of t (1; 11) and 6 cases of other abnormal karyotypes. A total of 19 cases (68%) were positive for KMT2A-R detected by FISH. The KMT2A fusion gene was detected by real-time PCR in 16 cases (57%). A total of 24 patients completed standardized induction chemotherapy and were able to undergo efficacy evaluation, 23 cases (96%) achieved complete remission through induction chemotherapy, 4 cases (17%) died of relapse. The 5-year event free survival rate (EFS) was (46±13)%, and the 5-year overall survival rate (OS) was (73±10)%.The survival time was 31.3 (3.3, 62.5) months. There was no significant statistical difference in 5-year EFS ((46±14)% vs. (61±18)%) and 5-year OS ((64±13)% vs. (86±13)%) between the KMT2A-R positive group (15 cases) and the KMT2A-R negative group (9 cases) (χ2=1.88, 1.47, P=0.170, 0.224). Conclusions: Most IALL patients were accompanied by KMT2A-R. They had poor tolerance to traditional chemotherapy, the relapse rate during treatment was high and the prognosis was poor.

[Willingness of HIV non-occupational post-exposure prophylaxis and related factors among men who have sex with men in Beijing]

Objective: To examine the willingness of HIV non-occupational post-exposure prophylaxis (nPEP) among MSM and factors related were also assessed. Methods: The respondent-driven sampling method was used to recruit MSM for a face-to-face interview with a structured questionnaire,the sample size was estimated at 600 subjects. Demographic data, sexual behavior, awareness, and willingness regarding nPEP were collected. The factors related to willingness to nPEP were assessed using complex logistic regression. Results: A total of 14 rounds were recruited and 608 MSM subjects were included in the study. The average age was (41.6±11.0) years. 55.4% (95%CI: 49.4%-59.4%) were aware of nPEP, and 4.5% (95%CI: 2.9%-6.2%) have used its. 35.9% (95%CI: 31.1%-40.7%) expressed interest in taking nPEP if needed. Among the reasons for not being willing to take nPEP, 68.9% (244/354) were never heard of nPEP, and 24.6% (87/354) were a fluke mentality. The multivariate logistic analysis results showed that the willingness of nPEP awareness of MSM was related to the group aged 25-39 years old (aOR=1.80, 95%CI: 1.01-3.20), knowing a group of HIV prevention knowledge (aOR=2.43, 95%CI: 1.52-3.90), group of consistent condom use in anal sex in the past half of year (aOR=1.76, 95%CI: 1.11-2.79). Conclusions: The use rate of nPEP among MSM in Beijing was low, and the willingness to use in the future also needs to be improved. The training of social organizations should be strengthened to improve the role of peer education in promoting nPEP.

[Histopathological evaluation of cirrhosis reversal]

A normal liver can develop cirrhosis through long-term and repeated stimulation from various etiologies. Histological manifestations like the collapse of hepatic lobular structure (including microvascular structure) and the formation of pseudolobules can lead to portal hypertension and even decompensated cirrhosis. More and more evidence suggests that effective etiological treatment can not only delay but also reverse the progression of cirrhosis. The mechanism of cirrhosis reversal mainly includes the degradation of extracellular matrix, hepatocyte regeneration, and hepatic lobular remodeling. The "gold standard" for the evaluation of cirrhosis reversal at present is still a liver biopsy. Therefore, the histopathological evaluation of cirrhosis reversal is very important for determining the disease's prognosis, efficacy, and mechanism of exploration.

[Interpretation of the essential updates in guidelines for the prevention and treatment of chronic hepatitis B (Version 2022)]

Chinese Society of Hepatology and Chinese Society of Infectious Diseases, Chinese Medical Association update the guidelines for the prevention and treatment of chronic hepatitis B (version 2022) in 2022. The latest guidelines recommend more extensive screening and more active antiviral treating for hepatitis B virus infection. This article interprets the essential updates in the guidelines to help deepen understanding and better guide the clinical practice.

[Different treatment strategies in patients with HBeAg-positive and negative chronic hepatitis B]

Patients with HBeAg-positive and negative chronic hepatitis B (CHB) have different immunological states and disease progression. Hence, the previously recommended antiviral therapy strategies for the two are different. In recent years, the antiviral indications have gradually eased, and the treatment goal has began to pursue clinical cure, as experts and scholars have gradually attached importance to the potential risk of disease progression in hepatitis B patients. Antiviral treatment strategies are gradually becoming uniform for patients with HBeAg-positive and negative. However, among them, HBeAg-negative patients can be combined with HBsAg quantification and other indicators to further screen the clinically cured dominant population in order to formulate the next treatment strategy.

[Expanding antiviral therapy for chronic hepatitis B: scale up screening and treatment]

The Chinese Society of Hepatology, Chinese Medical Association published "Expert Opinions on Expanding Antiviral Therapy for Chronic Hepatitis B" in 2022, with a focus on "active screening of the existing patients, paying attention to the potential risk of disease progression, and active intervening of the low level viremia," and recommended that specific actions be taken to further optimize the expanding screening, widening the antiviral indications, and scale up the diagnosis and treatment of low level viremia.

[Histological regression and clinical benefits in patients with liver cirrhosis after long-term anti-HBV treatment]

Objective: Our study aims to determine histological regression and clinical improvement after long-term antiviral therapy in hepatitis B virus-related cirrhosis patients. Methods: Treatment-naïve chronic hepatitis B patients with histologically or clinically diagnosed liver cirrhosis were enrolled. Liver biopsies were performed after 5 years entecavir-based antiviral treatment. Patients were followed up every 6 months. Cirrhosis regression was evaluated based on Metavir system and P-I-R score. Clinical improvement was evaluated before and after the long-term treatment. Kruskal Wallis test and Wilcoxon signed-rank test were used for continuous variables, Fisher's exact test was used for categorical variables and multivariate analysis was performed using logistic regression analysis. Results: Totals of 73 patients with HBV-related liver cirrhosis were enrolled. Among them, 30 (41.1%) patients were biopsy proved liver cirrhosis and the remaining 43 (58.9%) cirrhotic patients were diagnosed by clinical features. Based on Metavir system and P-I-R score, 72.6% (53/73) patients attained histological regression. Furthermore, 30.1% (22/73) were defined as significant regression (Metavir decrease ≥2 stage), 42.5% (31/73) were mild regression (Metavir decrease 1 stage or predominantly regressive by P-I-R system if still cirrhosis after treatment) and 27.4% (20/73) were the non-regression. Compared to levels of clinical characteristics at baseline, HBV DNA, ALT, AST, liver stiffness(decreased from 12.7 to 6.4 kPa in significant regression, from 18.1 to 7.3 kPa in mild regression and from 21.4 to 11.2 kPa in non-regression)and Ishak-HAI score significantly decreased after 5 years of anti-HBV treatment, while serum levels of platelets and albumin improved remarkably (P<0.05). In multivariate analysis, only the pre-treatment liver stiffness level was associated with significant regression (OR=0.887, 95%CI: 0.802-0.981, P=0.020). Conclusions: After long-term antiviral therapy, patients with HBV-related cirrhosis are easily to attain improvements in clinical parameters, while a certain percentage of these patients still cannot achieve histological reversal.

[Analysis of change in esophageal varices and clinical characteristics in hepatitis B virus-related cirrhosis after antiviral therapy]

Objective: To clarify the effect and related factors of antiviral therapy on the change of esophageal varices in patients with hepatitis B virus-related cirrhosis. Methods: Fifty-two cases with hepatitis B virus-related cirrhosis who underwent endoscopy before and after antiviral therapy were selected from prospective cohorts. Patients were divided into three groups: no, mild, and moderate-severe based on the degree of esophageal varices. The changes in the severity of esophageal varices in each group were compared after antiviral therapy. Clinical characteristics (platelet, liver and kidney function, liver stiffness, and virological response) of patients with different regressions were analyzed. Measurement data were analyzed by independent sample t-test, one-way ANOVA, Mann-Whitney U test and Kruskal-Wallis H test, and Chi-Square test was used for count data. Results: All patients received entecavir-based antiviral therapy. The median treatment time was 3.1 (2.5-4.4) years. The proportion of patients without esophageal varices increased from 30.8% to 51.9%, the proportion of mild esophageal varices decreased from 40.4% to 30.8%, and the proportion of patients with moderate-to-severe esophageal varices decreased from 28.8% to 17.3% (χ²=14.067, P=0.001). A total of 40.4% of patients had esophageal varices regression, and 13.5% had esophageal varices progression. The progression rate was significantly higher in patients with moderate-severe esophageal varices than patients with mild and no esophageal varices (χ²=28.126, P<0.001), and 60.0% of patients with moderate-severe esophageal varices still remained in moderate-severe state after antiviral treatment. Baseline platelet count and 5-year mean change rates were significantly lower in patients with progressive moderate-to-severe esophageal varices than in those without progression (+3.3% vs. +34.1%, Z=7.00, P=0.027). Conclusion: After effective antiviral treatment, 40.4% of patients with hepatitis B virus-related cirrhosis combined with esophageal varices has obtained esophageal varices regression, but those with moderate to severe esophageal varices still have a considerable risk of progression while receiving mono antiviral treatment only. Thrombocytopenia and without significant improving are the clinical signs of progression risk after receiving antiviral treatment.

[Reversal of hepatic fibrosis: more evidence and more challenges]

Hepatic fibrosis is a response to various types of hepatic injury, which can lead to cirrhosis and its complications. In recent years, in patients with viral hepatitis, nonalcoholic steatohepatitis, alcoholic liver disease, autoimmune liver disease and others the fibrosis or even early cirrhosis can be regressed if the etiology are controlled. Liver biopsy is still the gold standard for assessing fibrosis reversal, but non-invasive methods such as transient elastography hold great promise due to the ease to use for dynamic monitoring. Mechanisms of hepatic fibrosis reversal include extracellular matrix degradation, hepatocyte regeneration, and vascular remodeling. Presently, novel agents targeting the steps of fibrosis are urgently need for achieving regression of liver fibrosis.

[Low-level viremia-induced liver fibrosis and hepatocellular carcinoma in chronic hepatitis B]

Low-level viremia after antiviral therapy has gradually attracted attention due to its relation to liver fibrosis progression, hepatocellular carcinoma occurrence and long-term survival rate reduction in patients with chronic hepatitis B. In addition, it should be used as a risk factor for intervention during antiviral therapy in order to achieve complete virological response and improve the long-term prognosis of patients.

[Transmission chains of clusters of COVID-19 associated with a market in Beijing]

Objective: To investigate the clusters of COVID-19 associated with a market (market Y) in Haidian District, Beijing, and analyze the chain of transmission and provide reference for effective prevention and control of COVID-19. Methods: The investigation of field epidemiology and cluster epidemic was used to describe the distributions of all COVID-19 cases. The time sequence diagram of the cases, disease onset was drawn and transmission chains were analyzed. Real-time RT-PCR assay was conducted for SARS-CoV-2 nucleic acid test by using the respiratory samples of the cases. Results: The COVID-19 epidemic, originated from a wholesale farm produce market (market X) in Fengtai District, Beijing, was introduced by a marketer in the market Y who had exposed to market X, causing 8 clusters of 20 confirmed cases of COVID-19 and one asymptomatic case, including 8 men and 13 women, in market Y, surrounding communities, food plaza, companies,families and other places. The incidence peaked during June 10-14, 2020; the median age of the cases was 45 years, ranging from 5 years to 87 years. The initial symptoms of the cases included fever (10/20) and pharynx discomfort (7/20). The median of incubation period was 5 days (IQR:3-8). The median of serial interval between primary case and secondary cases was 5 days with a secondary attack rate of 3.7%(20/538), and the secondary attack rate in household close-contacts was 14.0% (7/50). Conclusions: The clusters of COVID-19 associated with market Y were caused by several modes of transmission, including human-to-human, contaminated material-to-human, etc. The combined public-health response measures were effective to control the COVID-19 epidemic in Haidian district of Beijing.

[Systematic evaluation of clinical trial protocols of new drugs as a cure of chronic hepatitis B]

Objective: To describe the current status of registration and design characteristics of clinical trials of new drugs for curing hepatitis B through domestic and foreign websites, so as to provide references for the follow-up clinical trials of new hepatitis B drugs. Methods: A search was conducted on the US Clinical Trials Database and the Chinese Clinical Trial Registry Center. The search date was from the establishment of the database to May 26, 2020, and the registration trials of new drugs for curing hepatitis B at home and abroad were included. Two researchers independently searched and screened the literature and extracted the data. Results: A total of 106 registered clinical trials of new drugs for curing hepatitis B were included (94 English registration websites and 12 Chinese registration websites), and the number of registrations had increased year by year. Among them, the proportion of therapeutic vaccines and core protein inhibitors were the highest, accounting for 27.4% (n = 29) and 22.6% (n = 24), respectively. The vast majority of clinical trials (n = 96, 90.6%) were in the early stages (Phase I and II). The subjects in phase I clinical trial were mainly healthy people and treated CHB patients, while the subjects in phase II clinical trial were mainly CHB patients who had achieved viral suppression after initial or post-treatment. The main evaluation indicators of Phase I clinical trials were the safety and tolerability of new drugs. The main evaluation indicators in about half of Phase II clinical trials were HBsAg negative conversion/quantitative decline. Overall, the number of clinical trials with the new design was small, accounting for 3.8% (4 / 106). There were relatively few trials of new drugs for curing hepatitis B on domestic registration websites, and the information provided was incomplete. Conclusion: The number of clinical trials of new hepatitis B drugs at home and abroad is increasing year by year, but most of them are in phase I and II, with few adopting new designs. In addition, the information integrity of the domestic website registration center needs to be improved.

[Retrospective investigation of patients receiving additional surgery after endoscopic non-curative resection for early colorectal cancer]

Objective: To investigate the clinical application of additional surgery after non-curative endoscopic resection for early colorectal cancer. Methods: A retrospectively descriptive cohort study was conducted. Inclusion criteria: (1) pathologically confirmed primary colorectal adenocarcinoma;(2) receiving additional surgery after endoscopic resection; (3) semi-elective operation. Exclusion criteria: familial adenomatous polyposis, appendiceal neoplasms, anal canal neoplasms, neuroendocrine tumors, and surgery because of perforation or bleeding after endoscopic resection. Indications of additional surgery: (1) pathologically positive lateral or basal resection margin; (2) submucosal invasion depth ≥ 1000 μm; (3) lymphovascular invasion; (4) poorly differentiated, undifferentiated or mucinous adenocarcinoma; (5) more than grade G2 in tumor budding; (6) incomplete resection or piecemeal specimen with margin impossible to evaluate; (7) patient's consent due to undetermined pathology. According to the above criteria, clinical data of 92 patients at the Colorectal Surgery Department, the First Affiliated Hospital of Nanjing Medical University between January 2013 and December 2018 were collected. Demographic data, pathological examinations, operative methods and outcomes were analyzed. Results: There were 61 (66.3%) male and 31 female (33.7%) patients with an average age of (58.2±10.7) years. The average BMI was (23.8±3.5) kg/m(2). The lesions located in the right-sided colon, left-sided colon and rectum in 19, 37 and 36 patients respectively. Sixteen patients received endoscopic snare resection, 45 received endoscopic mucosal resection and 31 received endoscopic submucosal dissection. Reasons for additional surgery included endoscopic specimen with pathologically positive margin (n=22, 23.9%), submucosal invasion depth ≥ 1000 μm (n=9, 9.8%), lymphovascular invasion (n=4, 4.3%), poorly differentiated, undifferentiated or mucinous adenocarcinoma (n=5, 5.4%), piecemeal resection (n=13, 14.1%), undetermined pathology (n=52, 56.5%). The median duration from endoscopic resection to additional surgery was 16 days. Thirty-four patients (37.0%) received preoperative endoscopic localization with carbon nanoparticles suspension injection and 5 (5.4%) were marked with titanium clip. Seventy-four patients (80.4%) received laparoscopic surgery, 17 (18.5%) received open surgery, while 1 patient (1.1%) was converted to open surgery due to missing titanium clip. Three patients (3.3%) were treated with transanal excision, 2 (2.2%) with bowel resection, and 87 (94.6%) with radical excision. After additional surgery, histopathological examination of surgical specimens revealed the presence of residual tumor in 5 patients (5.4%), lymph node metastasis in 8 (8.7%), lymphovascular invasion in 1 (1.1%) and tumor deposit in 1 (1.1%). Twelve patients (13.0%) developed postoperative complications, including 4 mid-low rectal cancer patients (4.3%) with anastomostic leakage or bleeding. After surgery, according to the TNM staging system, 83 patients (90.2%) were classified as TNM stage 0-I, 9 (9.8%) as TNM stage II-IV. One patient of stage IV with liver metastasis underwent concomitant hepatectomy. One patient of stage II received regular follow-up after operation. Seven cases of stage III and 1 of stage IV received postoperative chemotherapy. Eighty-five patients (92.4%) were followed up with a median time of 12.8 (IQR: 8.1, 24.3) months. No recurrence or metastasis was observed. Conclusions: Surgery is an effective salvage measure for non-curative endoscopic resection of early colorectal cancer. Since surgery may have complications, indications of the additional surgery should be considered carefully. Preoperative endoscopic localization should be performed in order to ensure the safety and efficacy of surgery.

TLR2 deficiency enhances susceptibility to oral carcinogenesis by promoting an inflammatory environment

Inflammation is closely related to oral squamous cell carcinoma (OSCC). However, its mechanism is still obscure. Toll-like receptor 2 (TLR2) plays an important role in oral chronic inflammatory diseases, but the role of TLR2 in OSCC is unclear. Here, we investigated the expression of TLR2 expression in OSCCs and examined the potential role of TLR2 in OSCC through its association with clinicopathological features and patient outcome. We used 4-nitroquinoline 1-oxide (4-NQO) to induce a tongue cancer model in TLR2-/- and wild type (WT) mice. Histological and clinical results both indicated that TLR2 played a protective role in oral tumorigenesis. The results of a cytometric bead array (CBA) indicated that TLR2 deficiency resulted in Th1 and Th2 cytokine abnormalities, especially Th2 abnormalities. Immunohistochemistry also showed that TLR2 deficiency increases the number of tongue-infiltrating M2 macrophages. Overall, our results demonstrated that TLR2 plays an important role in the prevention of oral tumorigenesis and affects the levels of Th2 cytokines and tongue-infiltrating M2 macrophages; therefore, it may be used to prevent the development of oral cancer.

[Qualitative pathological assessment of liver fibrosis regression after antiviral therapy in patients with chronic hepatitis B]

Objective: To investigate the methods for qualitative pathological assessment of dynamic changes in liver fibrosis/cirrhosis after antiviral therapy in patients with chronic hepatitis B (CHB), since antiviral therapy can partially reverse liver fibrosis and cirrhosis caused by hepatitis B and semi-quantitative, rather than qualitative, pathological assessment is often used for the research on liver fibrosis regression. Methods: Previously untreated CHB patients with liver fibrosis and cirrhosis were enrolled, and liver biopsy was performed before treatment and at 78 weeks after the antiviral therapy based on entecavir. The follow-up assessment was performed once every half a year. Based on the proportion of different types of fibrous septum, we put forward the new qualitative criteria called P-I-R classification (predominantly progressive, predominantly regressive, and indeterminate) for evaluating dynamic changes in liver fibrosis. This classification or Ishak fibrosis stage was used to evaluate the change in liver fibrosis after treatment and Ishak liver inflammation score was used to evaluate the change in liver inflammation after treatment. Results: A total of 112 CHB patients who underwent liver biopsy before and after treatment were enrolled, and among these patients, 71 with an Ishak stage of ≥3 and qualified results of live biopsy were included in the final analysis. Based on the P-I-R classification, 58% (41/71) were classified as predominantly progressive, 29% (21/71) were classified as indeterminate, and 13% (9/71) were classified as predominantly regressive; there were no significant differences between the three groups in alanine aminotransferase, aspartate aminotransferase, albumin, HBeAg positive rate, HBV DNA, and liver stiffness (P < 0.05). After treatment, the proportion of predominantly progressive, indeterminate, or predominantly regressive patients changed to 11% (8/71), 11% (8/71), and 78% (55/71), respectively. Among the 35 patients who had no change in Ishak stage after treatment, 72% (25/35) were classified as predominantly regressive and had certain reductions in the Laennec score, percentage of collagen area, and liver stiffness. Conclusion: This new P-I-R classification can be used to assess the dynamic changes in liver fibrosis after antiviral therapy in CHB patients.

[Surveillance for HIV infection in MSM selected through respondent driven sampling in Beijing, 2005-2012]

Objective: To understand the HIV prevalence among men who have sex with men (MSM) and discuss the feasibility of respondent driven sampling (RDS) as a tool to conduct long term HIV surveillance in MSM in Beijing. Methods: From 2005 to 2012 RDS was used to recruit MSM for face-to-face interview with structured questionnaire to collect their demographic characteristics and HIV risk-related behavior. Blood samples were collected from them for HIV test. Results: A total of 427, 540, 607, 614, 616, 602, 579 and 600 MSM were surveyed, respectively, from 2005 to 2012. The HIV infection prevalence increased from 4.2%(95%CI: 1.9-7.0) in 2005 to 10.1% (95%CI: 7.2-13.2) in 2012 (P=0.02). Meanwhile, HIV prevalence substantially increased among MSM aged >25 years, in floating population and with lower education level (≤high school), from 6.4%(95%CI: 2.2-9.5), 3.3%(95%CI: 1.8-5.4) and 5.5% (95%CI: 2.2-8.9) in 2005 to 7.6% (95%CI: 5.4-10.3, P=0.04), 10.7% (95% CI: 7.8-14.6, P=0.04) and 10.4% (95% CI:7.2-14.3, P=0.04) in 2012, respectively. Moreover, the HIV infection prevalence in MSM aged ≤25 years old and with higher education level (>high school) increased from 1.7%(95%CI: 0.4-3.1) in 2009 and 1.1%(95%CI: 0.2-1.7) in 2007 to 13.7%(95%CI: 7.2-20.4) and 9.1%(95%CI: 4.7-13.8) in 2012, respectively, the differences were not significant. Furthermore, the HIV infection prevalence in MSM who had 2-9 male sex partners in the last six months increased from 4.0% (95% CI: 1.0-8.0) in 2005 to 12.6% (95% CI: 8.7-16.7) in 2012 (P=0.02). Conclusions: Studies have shown that RDS is an effective and feasible sampling method for long term HIV surveillance in MSM. The HIV infection prevalence in MSM in Beijing increased from 2005 to 2012, especially among those with older age, in floating population and with lower educational level. More attention should be paid to MSM with younger age and with higher educational level.

[New advances in the diagnosis of liver fibrosis]

Various chronic liver diseases may progress to liver fibrosis or liver cirrhosis. Assessment of the degree of liver fibrosis helps with clinical decision-making, prognosis prediction, and evaluation of therapeutic effect, and therefore, accurate diagnosis and evaluation of the degree of liver fibrosis is a research hotspot at present. The advances in the diagnosis of liver fibrosis in recent years include the publication of international consensuses and guidelines, evaluation of the outcome of liver fibrosis after antiviral therapy, development of the diagnosis of liver fibrosis in patients with non-viral hepatitis, and constant update of noninvasive diagnostic techniques.

[Distribution and drug resistance of pathogens at hematology department of Jiangsu Province from 2014 to 2015: results from a multicenter, retrospective study]

Objective: To describe the distribution and drug resistance of pathogens at hematology department of Jiangsu Province from 2014 to 2015 to provide reference for empirical anti-infection treatment. Methods: Pathogens were from hematology department of 26 tertiary hospitals in Jiangsu Province from 2014 to 2015. Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or agar dilution method. Collection of drug susceptibility results and corresponding patient data were analyzed. Results: The separated pathogens amounted to 4 306. Gram-negative bacteria accounted for 64.26%, while the proportions of gram-positive bacteria and funguses were 26.99% and 8.75% respectively. Common gram-negative bacteria were Escherichia coli (20.48%) , Klebsiella pneumonia (15.40%) , Pseudomonas aeruginosa (8.50%) , Acinetobacter baumannii (5.04%) and Stenotropho-monas maltophilia (3.41%) respectively. CRE amounted to 123 (6.68%) . Common gram-positive bacteria were Staphylococcus aureus (4.92%) , Staphylococcus hominis (4.88%) and Staphylococcus epidermidis (4.71%) respectively. Candida albicans were the main fungus which accounted for 5.43%. The rates of Escherichia coli and Klebsiella pneumonia resistant to carbapenems were 3.5%-6.1% and 5.0%-6.3% respectively. The rates of Pseudomonas aeruginosa resistant to tobramycin and amikacin were 3.2% and 3.3% respectively. The resistant rates of Acinetobacter baumannii towards tobramycin and cefoperazone/sulbactam were both 19.2%. The rates of Stenotrophomonas maltophilia resistant to minocycline and sulfamethoxazole were 3.5% and 9.3% respectively. The rates of Staphylococcus aureus, Enterococcus faecium and Enterococcus faecalis resistant wards vancomycin were 0, 6.4% and 1.4% respectively; also, the rates of them resistant to linezolid were 1.2%, 0 and 1.6% respectively; in addition, the rates of them resistant to teicoplanin were 2.8%, 14.3% and 8.0% respectively. Furthermore, MRSA accounted for 39.15% (83/212) . Conclusions: Pathogens were mainly gram-negative bacteria. CRE accounted for 6.68%. The rates of Escherichia coli and Klebsiella pneumonia resistant to carbapenems were lower compared with other antibacterial agents. The rates of gram-positive bacteria resistant to vancomycin, linezolid and teicoplanin were still low. MRSA accounted for 39.15%.

Immunohistochemical localization of sex hormone receptors in two Raillietina tapeworms

Sex hormone receptors play critical roles in development and reproduction. However, it is not known whether they exist in Raillietina tapeworms, and if they do, whether they have a similar function to that in vertebrates. We examined the immunohistochemical distributions of androgen receptors (ARs), estrogen receptors (ERs), and progesterone receptors (PRs) in the tissues of two tapeworm species: Raillietina echinobothrida and Raillietina tetragona. Immunopositive ARs were found in the entire reproductive system of R. echinobothrida, including the testes, ovaries, and oocysts, and weakly immunopositive ERs and PRs were found in the testes, ovaries, and oocysts. Immunopositive ARs were also found throughout the entire reproductive system of R. tetragona, including the testes, ovaries, and oocysts, and weakly immunopositive ERs were in the testes and oocysts; the PRs were distributed in an immunonegative manner. The results show that androgens and their receptors play critical roles in reproductive system development in the two tapeworms. The immunoreactivity and tissue localizations of the sex hormone receptors suggest that, in both species, they have similar functions as in vertebrates, and modulate reproduction.

[A discussion of the methods for the assessment of chronic hepatitis B-related liver fibrosis regression]

Antiviral therapy could reverse hepatitis B-related liver fibrosis and early-stage cirrhosis. However, the assessment of fibrosis regression remains controversial. As the gold standard for assessment, liver biopsy has its own limitations. In terms of non-invasive assessment, there are many interfering factors for transient elastography and less clinical evidence for the use of serum markers. Therefore, further evidence from clinical studies is still needed to determine the role of non-invasive methods in evaluating fibrosis regression.

Protective effects of the sodium/calcium exchanger inhibitor on endothelial dysfunction induced by high glucose

This study was designed to investigate the protective effects of KB-R7943, an inhibitor of sodium/calcium exchanger (NCX) on endothelial dysfunction induced by high glucose in endothelial cells. NCX expression, NCX activity and oxidative stress index were determined after endothelial cells were exposed to high glucose in the absence and presence of KB-R7943. Coincubation of endothelial cells with high glucose for 6, 12, 24 and 48 h resulted in a significant decrease in NCX expression, superoxide dismutase (SOD) activity and the release of nitric oxide (NO), and increased NCX activity and malondialdehyde (MDA) production. These effects were abolished by KB-R7943. A similar effect was observed after treatment of endothelial cells with H-7, a protein kinase C (PKC) inhibitor and NADPH oxidase inhibitor (DPI). These results suggest that the sodium/calcium exchanger inhibitor exerts beneficial effects on high glucose-induced endothelial dysfunction, which may be related to PKC signal pathway.

Targeted metabolomic study indicating glycyrrhizin’s protection against acetaminophen-induced liver damage through reversing fatty acid metabolism

The present study aimed to give a short report on a possible mechanism of glycyrrhizin to acetaminophen-induced liver toxicity. Seven-day intraperitoneal administration of glycyrrhizin (400 mg/kg/day) to 2- to 3-month-old male C57BL/6N mice (mean weight 27 g) significantly prevents acetaminophen-induced liver damage, as indicated by the activity of alanine transaminase and aspartate aminotransferase. Metabolomics analysis and principal component analysis (PCA) using ultra-fast liquid chromatography coupled to triple time-of-flight mass spectrometer were performed. PCA separated well the control, glycyrrhizin-treated, acetaminophen-treated, and glycyrrhizin+acetaminophen-treated groups. Long-chain acylcarnitines were listed as the top ions that contribute to this good separation, which include oleoylcarnitine, palmitoylcarnitine, palmitoleoylcarnitine, and myristoylcarnitine. The treatment of glycyrrhizin significantly reversed the increased levels of long-chain acylcarnitines induced by acetaminophen administration. In conclusion, this metabolomic study indicates a significant glycyrrhizin protection effect against acetaminophen-induced liver damage through reversing fatty acid metabolism.

Coverage effect on reactivity can be more complicated than what you believe: H2 dissociation on H-precovered Pd(111)

A systematic investigation based on density-functional-theory calculations is presented for elucidating the effect of adatoms on the energetics of H2 dissociation on H-precovered Pd(111) surfaces. Surprisingly, we found that the H-adatoms do not only have a poisoning effect but can also promote H2 dissociation when they are adsorbed on sites which are sufficiently far from the dissociating H2 molecule. The presence of these antagonistic effects produces many crossovers of the minimum energy profiles for H2 dissociation when coverage is varied and thus leads to a quite perplexing picture for the adatom effects. We devised a sorting procedure which allows for rationalizing nicely the influence of H-adatoms on the energetics of H2 dissociation on H-precovered Pd(111) surfaces.

Effect of temperature change on power generation of microbial fuel cell

Microbial fuel cell (MFC), which can directly generate electricity from biodegradable materials, has been receiving increasing attention. Effects of temperature change on power density, electrode potential, columbic efficiency, chemical oxygen demand removal and internal resistance in two chambers MFCs were examined in this paper. The maximum power density of 7.89 W/m3 was achieved at 37 degrees C, with 199% higher at 10 degrees C (2.64 W/m3), 24% higher at 30 degrees C (6.34 W/m3) and 21% higher at 43 degrees C, no steady power generation was observed at 55 degrees C. Low temperature to 10 degrees C might have a huge effect on anode potential, especially at higher current, but increasing the temperature to 43 degrees C had a main effect on the cathode performance when the MFCs have been established at 37 degrees C. The internal resistance of MFC was about 29 omega at 37 degrees C, and increased 62% and 303% when MFC switched to 30 degrees C and 10 degrees C. Similarly, internal resistance increased 48% at 43 degrees C. The effect of temperature on MFC performance was expressed by internal resistance, the higher the internal resistance of MFC, the lesser the power density obtained. The Columbic efficiencies were 8.65% at 30 degrees C, 8.53% at 37 degrees C, and 13.24% at 43 degrees C. These results demonstrate that MFCs can effectively be operated over a wide range of temperatures.

A comparison of liver function after hepatectomy with inflow occlusion between sevoflurane and propofol anesthesia

BACKGROUND

In this study, we compared liver function tests after hepatectomy with inflow occlusion as a function of propofol versus sevoflurane anesthesia.

METHODS

One hundred patients undergoing elective liver resection with inflow occlusion were randomized into a sevoflurane group or a propofol group. General anesthesia was induced with 3 μg/kg fentanyl, 0.2 mg/kg cisatracurium, and target-controlled infusion of propofol, set at a plasma target concentration of 4 to 6 μg/mL, or sevoflurane initially started at 8%. Anesthesia was maintained with target-controlled infusion of propofol (2-4 μg/mL) or sevoflurane (1.5%-2.5%). The primary end point was postoperative liver injury assessed by peak values of liver transaminases.

RESULTS

Transaminase levels peaked between the first and the third postoperative day. Peak alanine aminotransferase was 504 and 571 U/L in the sevoflurane group and the propofol group, respectively. Peak aspartate aminotransferase was 435 U/L after sevoflurane and 581 U/L in the propofol group. There were no significant differences in peak alanine aminotransferase or peak aspartate aminotransferase between groups. Other liver function tests including bilirubin and alkaline phosphatase, and peak values of white blood cell counts and creatinine, were also not different between groups.

CONCLUSIONS

Sevoflurane and propofol anesthetics resulted in similar patterns of liver function tests after hepatectomy with inflow occlusion. These data suggest that the 2 anesthetics are equivalent in this clinical context.

[Compute simulation to characterize structure and function of chalcone synthase from Scutellaria baicalensis Georgi]

Prediction and analysis of molecular structure and biochemical function are of theoretical guiding significance for gene discovery and application, and considered as one of the central problem of computational biology. Here, some characteristic features of chalcone synthase (CHS) family from Scutellaria baicalensis were described via bioinformatic analysis, and showed as following: the nucleic acid sequences and amino acid sequences of three chs member genesshared high similarity inthe molecular structures and physicochemical properties; SbCHS proteins were localized to the cytosol, and possessed a good hydrophobic nature, with lacking any transmembrane topological structure. The phylogram analysis suggested that they were a group genes with significant functional association and genetic conservation. The secondary structures of the SbCHSs were mainly composed of alpha-helixes and random coils, and the tertiary structures contained malonyl CoA linkers, besides, each of CHS-A and CHS-B with N-glycosylation motif included. Taken together, these results demonstrate that CHS family from S. baicalensis has the typical molecular structure and function of chalcone synthase, compared with the experimental data for Medicago sativa CHS protein.

The effects of obstructive jaundice on the pharmacodynamics of propofol: does the sensitivity of intravenous anesthetics change among icteric patients?

BACKGROUND

Some studies suggest that certain clinical symptoms of cholestasis, such as fatigue and pruritus, result from altered neurotransmission. Patients with obstructive jaundice also have labile blood pressure and heart rate. In the present study, the authors investigated whether obstructive jaundice affects a patient's sensitivity to hypnotics and the haemodynamic profile of propofol.

METHODS

Thirty-six ASA physical status I/II/III patients with serum total bilirubin (TBL) from 7.8 to 362.7 micromol/l scheduled for bile duct surgery were recruited. A computer-controlled propofol infusion programmed for effect site target was used to rapidly attain and maintain sequential increase of the compartment concentration (from 1 to 3 microg/ml). Each target-controlled concentration was maintained for about 12 min, and arterial blood samples were drawn for propofol concentration determination. The bispectral index (BIS) and mean arterial pressures (MAP) were used as indices of the propofol effect. The relation between the concentration and the effects was described by the Hill equation. The pharmacodynamic parameters were optimized using a nonlinear mixed-effect model.

RESULTS

TBL was not a significant covariate of EC(50) for the pharmacodynamic model. For BIS and MAP, the parameters of the pharmacodynamic model were E(max)=75.77%, EC(50)=2.34 microg/ml, and gamma=1.82, and E(max)=47.83%, EC(50)=1.49 microg/ml, and gamma=1.88, respectively.

CONCLUSIONS

We demonstrated that obstructive jaundice with serum TBL from 7.8 to 362.7 micromol/l had no effect on propofol pharmacodynamics observed by BIS and MAP.

Pharmacokinetics, tissue distribution, and metabolism of novel DNA topoisomerase I inhibitor yuanhuacine in rabbit

A liquid chromatography/tandem mass spectrometry method was developed and validated for the quantitative determination of yuanhuacine (YHC), a daphne diterpene ortho-ester anticancer agent, and identification of its metabolites. Pharmacokinetic behaviour, tissue distribution, and metabolism were investigated in rabbit. YHC plasma data best fitted to a two-compartment model and were characterized by an elimination half-life t(1/2)(beta) of 11.1 h following intravenous administration. Tissue distribution studies did not identify any tissues having a high affinity for YHC. The main metabolites are proposed to be M392I, M392II, and M390, resulting from the ortho-ester group and aromatic ester bond being cleaved off simultaneously during Phase I metabolism. This investigation contributes to an understanding of the metabolism of daphne diterpene ortho-esters.

Preparation and characterization of Pd-Ti electrocatalyst on carbon supports for oxygen reduction

Nanoscale bimetallic Pd-Ti catalysts on carbon supports were prepared in liquid using ammonium tetrachloropalladate and titanium isopropoxide. The size of the metal particles ranged from subnanometer to greater than 10 nm, and the X-ray diffraction pattern of metal particles was dominated by a cubic crystalline structure. Depending upon the preparation conditions, the catalysts were comprised of Pd and TiO2 or Pd3Ti-like alloy. The surface Ti/Pd ratio was much greater than the original metal loading. We propose that the bimetallic particles were comprised of short-range Pd and TiO2 or Pd-Ti alloy nanocrystal covered by a thin TiO2 layer.

Downregulated NM23-H1 expression is associated with intracranial invasion of nasopharyngeal carcinoma

Because the focus of nasopharyngeal carcinoma (NPC) is very close to intracranial organs, it often makes incursions into cranial cavity. Identification of intracranial invasion-associated indicators will provide potential therapeutic targets for NPC patients with intracranial invasion. In this regard, Human Xpro™ HC-plus cancer-related gene chip was utilised to screen intracranial invasion-associated genes for NPC from the biopsied primary focus tissue samples. In all, 8 upregulated and 23 downregulated genes were obtained. VEGF165 and MMP-9, the two upregulated genes, and NM23-H1, the downregulated one, were further confirmed by immunohistochemistry, quantitative real-time PCR and western blot. Invasion-associated cellular and nude mouse models were subsequently employed to study the biological properties of NM23-H1. NM23-H1 expression was significantly lower in 5-8F cells compared with that in 6-10B cells. Moreover, patch-clamp and transwell chamber were adopted to investigate the invading potential-associated biological dynamic mechanisms in the two cell lines, and Ca²⁺ current and motility were significantly elevated in 5-8F cells compared with that in 6-10B cells. Berberine, an inhibitor of Ca²⁺ current, could substantially increase the expression of NM23-H1 and decrease 5-8F cell motility. The specificity of berberine on NM23-H1 and cell motility was confirmed by RNAi assay.

Enhanced resonance energy transfer from PVK to MEH-PPV in nanoparticles

Organic semiconductor nanoparticles were prepared from poly(N-vinylcarbazole) (PVK), poly(2-methoxy-5-(2(')-ethyl-hexyloxy)-p-phenylene vinylene) (MEH-PPV) and their blend solution via a reprecipitation method, respectively. A wide photoluminescence band centred at 430 nm has been found in the PVK nanoparticles, which is obviously red-shifted by comparison with the PVK film. The red-shifted emission from the PVK nanoparticles has a good spectral superposition with the absorption of the MEH-PPV nanoparticles. However, the spectral superposition is very poor between the two polymers in the composite films. The markedly enhanced emission from MEH-PPV is experimentally observed in the composite polymer nanoparticles and attributed to Förster energy transfer from PVK to MEH-PPV for excitation at the absorption maximum of PVK.

[Substance P regulates function of osteoclasts via neurokinin-1 receptor]

OBJECTIVE

To investigate the effects of substance P on cultured rat osteoclasts.

METHODS

Neurokinin-1 (NK1) receptor expression in osteoclasts was examined by immunohitochemical method, and changes of bone resorption activity caused by substance P and NK1 receptor antagonists were detected by pit formation assay.

RESULTS

Immunoreactivity for NK1 receptor was distributed in the cytoplasm of osteoclasts. The average of pit formation areas significantly increased with addition of substance P (10(-7)-10(-4) mol/L) (P < 0.05), but the number of pitformations did not change (P > 0.05). NK1 receptor antagonists inhibited the enhancement of the bone resorption by substance P addition.

CONCLUSION

The findings suggested that substance P may stimulate osteoclasts and result in bone resorption by the mediation of NK1 receptor.

Cluster characterisation and temporal expression of porcine sarcomeric myosin heavy chain genes

Members of the myosin heavy chain (MyHC) gene family are subjected to temporal regulation of gene switching during development. One strategy to the identification of cis-acting regulatory elements that are involved in temporal or fibre-type specific regulation is to undertake a comparative analysis of the MyHC gene family between the pig, an important target species, and other mammals, like human whose entire genome has been recently sequenced. Towards this end, we report here on the isolation, and characterisation of the porcine cardiac (MyHC slow/beta and alpha) and skeletal MyHC (embryonic, 2a, 2x, 2b and perinatal) gene clusters, and their structural comparisons with mouse and human clusters. The genome organisation of both clusters in the pig, human and mouse is conserved as having the same gene order, similar intergenic distances, and in the same head-to-tail orientation. For a period of pre-natal muscle growth, relative expression of MyHC isoforms, as determined by TaqMan real-time RT-PCR, correlated with the gene order in the skeletal MyHC cluster (embryonic > 2a > 2x > 2b) suggesting the possible presence of DNA elements on the same side as the MyHC embryonic gene that direct temporal regulation.

Molecular and quantitative characterisation of the porcine embryonic myosin heavy chain gene

The porcine embryonic myosin heavy chain (MyHC) is a major isoform in foetal skeletal muscle, and is the last remaining major porcine skeletal MyHC gene to be isolated and characterised. We report here on its cDNA and genomic isolation, molecular characterisation, quantification and expression. Unlike all other porcine and mammalian skeletal MyHC genes reported to date, the deduced translated start site of the porcine embryonic gene was located in exon 2, instead of exon 3. Its promoter conferred differentiation-specific expression. We found, by quantitative real-time RT-PCR, that for much of gestation the embryonic MyHC was by far the most transcriptionally active gene compared with the slow/I and perinatal MyHC isoforms, and it was consistently more highly expressed than the perinatal isoform throughout gestation. The embryonic MyHC isoform was, however, rapidly down-regulated at around birth. By contrast, 22 weeks after birth, the porcine perinatal isoform remained detectable by PCR. Additionally, we discovered the presence of differential splicing at the 3'-end of the embryonic MyHC gene that resulted in an in-frame deletion, with the consequential loss of 93 amino acids close to the ACD domain, a region that is important for the assembly of myosin filaments. The detection of this truncated variant points to a possible major post-transcriptional mechanism of embryonic MyHC regulation that may be linked to myosin filament formation or turnover.

[Application of artificial neural network to simultaneous spectrophotometric determination of Cu, Co and Ni]

By means of artificial neural network and Levenberg-Marquardt back-propagation train algorithm, the three-component metal coordinate compounds of PAR-Cu, Co, Ni were determined simultaneously, in which the spectra overlapped. In 452-552 nm, the absorbance(A) at 14 wavelength were taken as character of artificial neural network, and samples were arranged by method of orthogonal design. The mean recovery of Cu, Co, Ni were 99.96%, 99.99% and 99.97% respectively. The RSD of the results were 0.1%, 0.2% and 0.1% respectively. The results were better than those of other networks in training speed and the accuracy. In conclusion, the new network spectrophotometry is a good choice for resolving multicomponent.

A chicken gonadotropin-releasing hormone receptor that confers agonist activity to mammalian antagonists. Identification of D-Lys(6) in the ligand and extracellular loop two of the receptor as determinants

Mammalian receptors for gonadotropin-releasing hormone (GnRH) have over 85% sequence homology and similar ligand selectivity. Biological studies indicated that the chicken GnRH receptor has a distinct pharmacology, and certain antagonists of mammalian GnRH receptors function as agonists. To explore the structural determinants of this, we have cloned a chicken pituitary GnRH receptor and demonstrated that it has marked differences in primary amino acid sequence (59% homology) and in its interactions with GnRH analogs. The chicken GnRH receptor had high affinity for mammalian GnRH (K(i) 4.1 +/- 1.2 nM), similar to the human receptor (K(i) 4.8 +/- 1.2 nM). But, in contrast to the human receptor, it also had high affinity for chicken GnRH ([Gln(8)]GnRH) and GnRH II ([His(5),Trp(7),Tyr(8)]GnRH) (K(i) 5.3 +/- 0.5 and 0.6 +/- 0.01 nM). Three mammalian receptor antagonists were also pure antagonists in the chicken GnRH receptor. Another three, characterized by D-Lys(6) or D-isopropyl-Lys(6) moieties, functioned as pure antagonists in the human receptor but were full or partial agonists in the chicken receptor. This suggests that the Lys side chain interacts with functional groups of the chicken GnRH receptor to stabilize it in the active conformation and that these groups are not available in the activated human GnRH receptor. Substitution of the human receptor extracellular loop two with the chicken extracellular loop two identified this domain as capable of conferring agonist activity to mammalian antagonists. Although functioning of antagonists as agonists has been shown to be species-dependent for several GPCRs, the dependence of this on an extracellular domain has not been described.

Transport properties of ionic drugs in the ammonio methacrylate copolymer membranes

PURPOSE

Ammonio methacrylate copolymer is a pharmaceutical excipient widely used as a coating material for encapsulation of pellet and tablet dosage forms. Because of the charged ammonio function groups within the polymer, ionic drugs may interact with the coating film while transporting through it. The kinetic swelling and drug permeation properties of the ammonio methacrylate copolymer membranes were studied to delineate the effect of ionic interaction between the ionic drugs and the membranes.

METHODS

The pH and ionic strength of the solutions and the charged properties of drugs were varied to study the effects on the transport properties through the membranes. Ambroxol was chosen as a model cationic drug and aspirin as a model anionic drug.

RESULTS

The degree of membrane swelling in the drug-free solution decreases as the ionic strength increases but it is irrelevant to the pH. With the presence of ionic drugs, the degree of membrane swelling is affected by the drug species as well as the pH of the solutions in addition to the effect of ionic strength. The degree of swelling for a membrane in a solution containing aspirin is higher at a lower pH and ambroxol is lower at a lower pH. Aspirin experiences a three-stage permeation and ambroxol a two-stage one. The ion-exchange reaction between the anionic carboxylic groups in aspirin and the cationic ammonio groups in the membranes results in a slow permeation stage during the transient state. The pseudo steady-state permeability for each drug follows the trend as the degree of membrane swelling in the drug media at various pH and ionic strengths. However, it is much higher for aspirin than ambroxol although the degree of membrane swelling is higher in an ambroxol solution than that in an aspirin solution. The permeability of ambroxol through the membrane is largely reduced because of the Donnan exclusion effect.

CONCLUSIONS

The interaction between ionic drugs with the cationic groups in the membranes affects the ionic strength of the solutions and results in a pH-dependent degree of swelling. The ionic interaction also determines the drug permeation rates as well as the transient permeation behaviors.

Distribution and regulation by oestrogen of fully processed and variant transcripts of gonadotropin releasing hormone I and gonadotropin releasing hormone receptor mRNAs in the male chicken

The aim of this study was to increase understanding of the occurrence and regulation of chicken gonadotropin releasing hormone I (cGnRH I) and chicken gonadotropin releasing hormone receptor (cGnRH-R) mRNA variants in the hypothalamic-pituitary-testicular axis (HPTA). The study was carried out in the cockerel. Fully processed cGnRH I mRNA (cGnRH Ia) and a variant transcript (cGnRH Ib) with a retained intron 1 were observed in the preoptic/anterior hypothalamus (POA), the basal hypothalamus, anterior pituitary gland, and testes. Fully processed cGnRH-R mRNA (cGnRH-Ra) and a variant transcript (cGnRH-Rb) with a deletion were detected in the same tissues. In juvenile cockerels, concentrations of cGnRH Ia and b in the POA increased after castration, and this was prevented by oestrogen treatment. In the anterior pituitary gland, the concentration of cGnRH-Ra increased after castration and this was reversed by oestrogen treatment. In intact adult cockerels, oestrogen treatment depressed plasma luteinizing hormone but did not affect concentrations of cGnRH I and cGnRH-R mRNAs in the POA, basal hypothalamus, and anterior pituitary gland, suggesting that locally produced oestrogen, by aromatization, may exert maximal suppression on cGnRH I and GnRH-R mRNAs. In intact adult cockerels, the concentrations of cGnRH Ia and b in the testis, but not cGnRH-Ra and b, were depressed by oestrogen treatment. It was concluded that fully processed and variant cGnRH I and cGnRH-R mRNAs occur in all components of the HPTA. Oestrogen appears to play a role in the regulation of cGnRH Ia and b in the POA and testes, and of cGnRH-Ra in the POA and anterior pituitary gland.

[Studies on the construction and expression of recombinant human fusion gene Nm23-H1/HbFGF in Escherichia coli]

First, a piece of intermediate nucleic acid chain was designed according to the nucleic acid sequences of Nm23-H1 and HbFGF cDNA, then it was combined with the upstream primer of Nm23-H1 or the downstream primer of HbFGF to perform Polymerase Chain Reaction (PCR) respectively. The fusion gene Nm23-H1/HbFGF was constructed by four steps of PCR, and it was cloned into the plasmid vector pBV220. The recombinant was induced at 42 degrees C and analyzed by SDS-PAGE. Results show that the fusion gene Nm23-H1/HbFGF highly expresses its product in inclusion body in E. coli BL21(DE3). The expressing product is 14% of the total bacterial protein and it is 34 kD. ELISA assay and Western blot indicate that the inclusion body contains antigens of Nm23-H1 and HbFGF. By denaturation, renaturation and purification, the inclusion body was purified. Determination and biological activity assay show that the purified product contains two kinds of antigens which have biological activities of Nm23-H1 and HbFGF. All these data establish good base to study the tumor suppressor activity and oncogenicity of the fusion gene Nm23-H1/HbFGF in eukaryocyte.

The 5'-end of the porcine perinatal myosin heavy chain gene shows alternative splicing and is clustered with repeat elements

The porcine perinatal myosin heavy chain (MyHC) is a major isoform in foetal skeletal muscles. We report here on its cDNA and genomic isolation, molecular characterisation and expression. Exon 2 and the first 4 bases of exon 3 of the perinatal MyHC gene. both part of the 5'-end untranslated region, showed differential splicing. About 2% of all perinatal MyHC transcripts of a 50-day-old foetus were without exon 2 and about half were without the 4 bases at the 5'-end of exon 3. Perinatal MyHC mRNA was expressed in all hind limb muscles of a 45-day-old foetus along with the slow and embryonic MyHC isoforms in the same fibres. Unlike other sarcomeric MyHCs reported to date, the porcine perinatal promoter is clustered with repeat elements (4 SINEs and 1 microsatellite) and is without a consensus TATA box at the predicted site upstream of exon 1. Nonetheless, in reporter gene transfections, its promoter was found to be highly muscle-specific. The absence of a TATA box may point to a fundamental difference in the regulatory function between the perinatal and adult MyHC isoforms.

Preparation and characterization of alpha-amylase-immobilized thermal-responsive composite hydrogel membranes

Composite hydrogel membranes of crosslinked poly(N-isopropylacrylamide-co-N-acryloxysuccinimide-co-2-hydroxyet hyl methacrylate) [P(NIPAAm-NAS-HEMA)] with starch, as a macropore forming agent, on nonwoven polyester was prepared. The membranes could swell and de-swell around the characteristic lower critical solution temperature (LCST) of poly(N-isopropylacrylamide) (PNIPAAm). It was demonstrated that the presence of macropores in the membranes could improve the immobilization efficiency as well as lead to a short responding time upon temperature change across the LCST. Immobilized alpha-amylase could retain as high as 33% of the activity of the free enzyme with a loading level of 0.60-0.65 mg/cm2 when the membrane preparation and enzyme immobilization conditions were optimized. The half time (T0.5) for the swelling or de-swelling response of the gel phase within the membranes was less than 2 min, and the 90% time (T0.9) was less than 6 min. The permeability for maltose through the membranes could change as much as 4.9-fold when the temperature was raised above or reduced below the LCST.

Identification of three putative GnRH receptor subtypes in vertebrates

The majority of vertebrates have two or three forms of gonadotropin-releasing hormone (GnRH), which appear to have arisen by successive gene duplication events. This suggests the possibility of concordant gene duplications of the GnRH receptor to produce two or more cognate receptors. Since the extracellular loop 3 (EC3) domain of mammalian GnRH receptors plays a role in distinguishing the different forms of GnRH, we have contemplated that the sequence of this domain will differ significantly in the putative cognate receptors. Degenerate oliognucleotides encoding the sequences of the transmembrane domains preceding and following EC3 were used for PCR amplification of genomic DNA from zebrafish (Brachydanio rerio), goldfish (Carassius auratus), African clawed frog (Xenopus laevis), chicken (Gallus domesticus), and lizard (Agama atra). Isolation and sequencing of specific clones revealed that they fell into three groups. Two of these were most similar to the mammalian pituitary GnRH receptor and were therefore designated Type IA and Type IB. The third form (designated Type II) was most different from the others and was identified in Xenopus, lizard, and human DNA. These findings support the concept of the existence of three distinct GnRH receptors, which have evolved in conjunction with three distinct GnRH ligand classes present in many vertebrates.

Cloning and characterization of the chicken thyrotropin-releasing hormone receptor

We report on the cloning of the full-length complementary DNA for the chicken TRH receptor. Although the TRH receptor has been cloned from several mammalian species, this is the first report from another vertebrate class. The ligand binding pocket, which is situated in the transmembrane helices of the mouse and rat TRH receptors, is completely conserved in the chicken receptor. Pharmacological studies (receptor binding and signaling) employing several TRH analogs revealed that there are no significant differences between the chicken and mouse receptors. These findings show that there have been considerable evolutionary constraints on TRH receptor structure and function. Several truncated forms of the chicken TRH receptor that appear to retain a part of an intron and are truncated in the putative third intracellular loop were also cloned, but were nonfunctional. This study provides a useful tool for further studies on the roles of TRH in avian growth and TSH regulation.