[Survey on the awareness rate of mpox knowledge and related factors among men who have sex with men in China]

Objective: To understand the awareness rate of mpox knowledge and related factors among men who have sex with men (MSM) in China. Methods: The survey was conducted among men aged ≥18 years who had sex with men in the past year, using the convenience sampling method. The estimated sample size was 4 312. With the assistance of social organizations of MSM in 30 provinces in China, an online questionnaire survey was conducted using anonymous self-designed questionnaires powered by www.wjx.cn during 10-14 August 2023 to collect information on socio-demographic characteristics, awareness of mpox knowledge, travel history, and sexual behaviors of the respondents. The software SAS 9.4 was used for statistical analysis. Results: There were 7 725 respondents, and the age of the respondents was (31.6±9.0) years. The results revealed that the awareness rate of mpox knowledge was 50.1% (3 872/7 725). The main routes to acquire mpox knowledge were mainly new media, including WeChat, Weibo, TikTok, and Blued social software (88.4%,6 827/7 725), while official media report was the most trusted way to acquire related knowledge (79.3%,6 129/7 725). Multivariate logistic regression analysis revealed that the factors indicated a higher awareness rate of mpox knowledge, including living in the western region or the eastern region, people were over 26 years old in early adulthood and midlife, college-educated or with higher degrees, living in towns or urban periphery, being in homosexual or in bisexual relationships, 1-5 homosexual times/months in the past 3 months, knowing their HIV infection status, paying attention to mpox knowledge very often, occasionally or rarely, and convenient ways to acquire mpox knowledge from new media and social organizations. Conclusions: The awareness rate of mpox knowledge was low among MSM in China. Efforts should be made to improve the awareness rate of mpox knowledge among those who are young, less educated, or sexually active, with targeted health education via new media and social organizations.

[Characteristics of baseline viral load before antiretroviral therapy in newly reported HIV-infected patients in Tianjin, 2019-2022]

Objective: To understand the baseline viral load (VL) of newly reported HIV- infected patients before antiretroviral therapy and related factors in Tianjin. Methods: Data were obtained from the China Disease Control and Prevention Information System, and the study subjects were HIV-infected patients before the first antiretroviral therapy in Tianjin from 2019 to 2022, and the information about their socio-demographic characteristics, baseline CD4+T lymphocyte (CD4) counts before antiretroviral therapy and baseline VL test results were collected, the baseline high VL was defined as ≥100 000 copies/ml. The effect of different factors on viral load were analyzed. Software SPSS 24.0 was used for statistical analysis. Results: A total of 1 296 newly reported HIV-infected patients were included in the study, in whom 15.89% (206/1 296) had high baseline VL, and multifactorial logistic regression analysis showed that those with history of STD (aOR=1.45, 95%CI:1.00-2.08) were more likely to have high baseline VL. Compared with those with baseline CD4 counts <200 cells/μl, those with baseline CD4 counts 200-350 cells/μl (aOR=0.40, 95%CI: 0.27-0.57), 351-500 cells/μl (aOR=0.32, 95%CI: 0.20-0.49), and >500 cells/μl (aOR=0.30, 95%CI: 0.18-0.49) were less likely to have high baseline VL. Conclusions: The proportion of HIV-infected patients with high baseline VL before antiretroviral therapy was low in Tianjin during 2019-2022. History of STD and baseline CD4 counts <200 cells/μl were associated with high baseline VL in HIV-infected patients, to which close attention needs to be paid in AIDS prevention and control.

[Sexually active status and its correlates among community-based older adults in Tianjin]

Objective: To understand the sexually active status among community-based older adults aged ≥50 years in Tianjin, China, and to explore the potential correlates. Methods: A cross-sectional survey using multistage sampling among community-based older adults aged ≥50 was conducted between June 2020 and December 2022. The estimated sample size was 735. The survey collected questionnaire information through face-to-face interviews with investigators, including sociodemographic, health, and sexual lifestyle characteristics. The multivariable logistic regression model was used to assess correlates of sexually active status. Results: A total of 776 study participants (510 males and 266 females) were included, whose major age distribution was 50-59 years (45.9%). The overall sexual activity prevalence of the participants was 45.6%. Older age (60-69: aOR=0.67, 95%CI: 0.45-0.99; ≥70: aOR=0.12, 95%CI: 0.07-0.21), being male (aOR=1.93, 95%CI: 1.32-2.82), living in urban area (aOR=0.18, 95%CI: 0.12-0.28), living with spouse/married (aOR=2.80, 95%CI: 1.41-5.58), living alone (aOR=0.51, 95%CI: 0.27-0.96), having difficulty climbing stairs or walking (aOR=0.55, 95%CI: 0.31-0.97), having chronic diseases (one chronic disease: aOR=0.55, 95%CI: 0.36-0.85; two or more chronic diseases: aOR=0.53, 95%CI: 0.33-0.84) were associated with sexually active status among older adults. Conclusions: Many community-based older adults remained sexually active. There was an association between physical health and sexually active status among community-based older adults. Incorporating sexual health services into healthcare services for community-based older adults could be advocated, with a concurrent emphasis on enhancing the awareness and competence of providing sexual health services among community-based healthcare workers.

[Estimate the population size of transgender women based on the capture-recapture method in Tianjin]

Objective: To investigate the population size of transgender women (TGW) in Tianjin and analyze the characteristics of their sexual behaviors to provide a basis for AIDS prevention and control. Methods: To estimate the population size of TGW in Tianjin using the capture-recapture method. At the same time, an anonymous questionnaire was collected to conduct a multi-factor logistic analysis of the TGW population's sexual behavior. Results: A total of 213 TGW were investigated. Tianjin's estimated TGW population size was 599 (95%CI: 407-792). Multivariate logistic analysis of the use of condoms consistently showed that compared with TGW without regular sex partners, those with regular sex partners had a lower proportion of consistent condom use (aOR=0.44, 95%CI: 0.23-0.82) and had received HIV tests in the last year were more likely to adhere to condom use than those who had not been tested (aOR=2.73, 95%CI: 1.06-6.99). Conclusion: It is necessary to strengthen HIV mobilization testing among the TGW population and their regular sexual partners to improve condom use.

Activity of bovine lactoferrin in resistance to white spot syndrome virus infection in shrimp

White spot syndrome virus (WSSV) is a notorious pathogen that has plagued shrimp farming worldwide for decades. To date, there are no known treatments that are effective against this virus. Lactoferrin (LF) is a protein with many bioactivities, including antiviral properties. In this study, the activities and mechanisms of bovine LF (bLF) against WSSV were analyzed. Our results showed that bLF treatment significantly reduced shrimp mortalities caused by WSSV infection. bLF was found to have the ability to bind to surfaces of both host cells and WSSV virions. These bindings may have been a result of bLF interactions with the host cellular chitin binding protein and F1 ATP synthase β subunit protein and the WSSV structural proteins VP28, VP110, VP150 and VP160B. bLF demonstrated potential for development as an anti-WSSV agent in shrimp culture. Furthermore, these reactionary proteins may play a role in WSSV infection.

[Analysis on psychoactive substances use in men who have sex with men in Tianjin]

Objective: To understand the use of psychoactive substances and its related factors in men who have sex with men (MSM) in Tianjin. Methods: A cross-sectional survey was conducted in MSM recruited in Tianjin by snowball sampling from September 2017 to December 2020, the information about their social demographic information, use of psychoactive substances and behavioral characteristics were collected, meanwhile the blood samples were taken from them for HIV/syphilis detections. Multivariate logistic regression was used to explore related factors about psychoactive substances use. Results: A total of 9 218 MSM were included in the study, in whom 43.5% (4 013/9 218) had ever used psychoactive substances, including 92.6% (3 718/4 013)who used Rush and 17.2% (692/4 013) who used multi substances. Multivariate analysis showed that, the OR of psychoactive substances use in MSM who were in Han ethnic group was 0.68 (95%CI:0.51-0.91) compared with those who were in minor ethnic group; the OR of psychoactive substances use in MSM who were married or cohabited, divorced or widowed were 0.65 (95%CI: 0.57-0.71), 0.80 (95%CI: 0.65-0.97) respectively compared with those who were unmarried; the OR of psychoactive substances use in MSM who had the first homosexual sex at age of ≥30 years was 0.57 (95%CI: 0.44-0.74) compared with those who had the first homosexual sex at age of <30 years; the OR of psychoactive substances use in local MSM in Tianjin was 1.12 (95%CI: 1.03-1.23) compared with those who were not local residents in Tianjin; the OR of psychoactive substances use in MSM with education level of college or above was 1.29 (95%CI: 1.12-1.49) compared with those with education level of junior middle school or below; the OR of psychoactive substances use in MSM who had anal sex in the past six months was 1.93 (95%CI: 1.34-2.77) compared with those who had no anal sex; the OR of psychoactive substances use in MSM who had >2 homosexual partners in the last week was 1.62 (95%CI: 1.41-1.87) compared with those who had ≤2 homosexual partners; the OR of psychoactive substances use in MSM who had homosexual commercial sex in the past six months was 1.99 (95%CI: 1.62-2.45) compared with those who had no homosexual commercial sex; the OR of psychoactive substances use in MSM who had sexually transmitted diseases in the last year was 2.39 (95%CI: 1.82-3.12) compared with those who had no sexually transmitted diseases and the OR of psychoactive substances use in MSM who received peer education services in the last year was 1.63 (95%CI: 1.50-1.78) compared with those who received no peer education services. Conclusion: The prevalence of psychoactive substances use is high in MSM in Tianjin, and there are many influencing factors. It is necessary to conduct targeted interventions according to the influencing factors.

[HIV infection status in male outpatients in sexually transmitted disease clinics in Tianjin, 2016-2020]

Objective: To understand the HIV infection status in male outpatients in sexually transmitted disease (STD) clinics in Tianjin from 2016 to 2020. Methods: According to the sentinel surveillance protocol, continuous cross-sectional studies were conducted between April and June during 2016-2020 to collect the information about the awareness of AIDS related knowledge, related sex behaviors, HIV infection, syphilis prevalence and HCV infection of male STD outpatients in Tianjin with a sample seize of 400 in each sentinel clinic. Results: From 2016 to 2020, a total of 4 000 male STD outpatients were surveyed. The HIV positive rate increased from 1.13% (9/800) to 2.25% (18/800) (trend χ²=14.22, P<0.001), the positive rate of syphilis increased from 9.38% (75/800) to 13.00% (104/800) (trend χ²=7.30, P=0.007) in this population during this period. The overall HCV positive rate was 0.45% (18/4 000). Multivariate logistic regression analysis showed that compared with those who were unmarried, had registered residence in Tianjin, had no temporary sexual behavior in the past 3 months, had no anal sex and had negative syphilis test result, the risk factors of HIV infection in the male STD outpatients included cohabitation (aOR=7.53, 95%CI:2.13-26.62), being from other provinces (aOR=3.64,95%CI:1.58-8.38), having temporary sexual behavior in the past 3 months (aOR=2.24,95%CI:1.03-4.89), having homosexual anal sex (aOR=85.99,95%CI:38.76-190.74) and suffering from syphilis (aOR=6.06,95%CI:3.18-11.56). Conclusion: The detection rates of HIV infection and syphilis in male STD outpatients in Tianjin showed upward trends from 2016 to 2020. Having temporary sexual behavior and anal sex, and suffering from syphilis were the main risk factors of HIV infection in male STD outpatients.

[A cohort study on the incidence of HIV infection in drug abusers among men who have sex with men in Shanghai and Tianjin]

Objective: To analyze the incidence of HIV infection and identify associated risk factors in drug abusers among men who have sex with men (MSM) in Tianjin and Shanghai through a cohort study and provide a basis for HIV prevention in this population. Methods: A prospective cohort study was conducted among MSM who had a history of drug abuse in the past six months from June 2016 to June 2018 in the two cities. MSM were investigated to obtain information on sociodemographic characteristics, HIV-related sexual behaviors, and drug abuse. Follow-up investigation and HIV testing were carried out based on the baseline survey and testing. Cox regression analysis was conducted to identify the risk factors for HIV infection. Results: There were 455 eligible subjects, and 16 new HIV infection cases were identified in the 2-year follow-up survey. The cumulative follow-up time was 586.08 person-years, and the incidence of HIV infection was 2.73/100 person-years. The multivariate Cox regression analysis results showed that compared with those aged ≥25 years, consistent condom use during anal sex with men in the past six months, without mixed-use of drugs, these aged <25 years (HR=5.01, 95%CI: 1.09-23.11), inconsistent condom use during anal sex with men in the past six months (HR=1.58, 95%CI: 1.04-2.41) and mixed-use of drugs (HR=1.92, 95%CI: 1.08-3.40) were significantly associated with HIV infection in this cohort. Conclusions: The younger age, inconsistent condom use during anal sex with men, and mixed drug use appeared as risk factors of new HIV infection in drug abusers among MSM. HIV prevention and intervention in this population should be further strengthened.

[Clinical and prognosis analysis of children with kidney retransplantation]

Objective: To analyze the clinical and prognosis of children with kidney retransplantation. Methods: Clinical data of 11 children who underwent kidney retransplantation from January 2011 to December 2020 in Department of Nephrology, Children's Hospital of Fudan University were retrospectilely analyzed. The clinical data including demographic parameters, primary diagnosis, characteristics in the follow-up of renal allograft were analyzed. Results: Totally 11 cases received secondary renal transplantation (male 6, female 5). They were initially diagnosed with chronic kidney disease at the age of 11.9 (7.4, 13.3) years. The median duration of dialysis was 22.1 (3.5, 36.5) months. In the first transplantation, recipient age was 13.9 (11.1, 15.2) years. Ten cases received donation from cardiac death donor (DCD) (9 cases received donors aged less than one year, 5 of them received whole kidney transplantation and one case received donor aged one to three years) and 1 case with living-related donor. Ten graft failures occurred within 1 month after renal transplantation and the other one occurred at the fifth month after transplantation. The causes included vascular factors (9 cases), rejection (1 case) and primary non-function (1 case). In the second transplantation, recipient age was 14.7 (11.7, 16.2) years. All the 11 children received dialysis (7 with PD and 4 with HD) and successfully completed the second transplantation. The median time between the two transplants was 210 (16, 1 041) days. Donors were all DCD donors from 3 years of age or older. The mean follow-up duration was (42±15) months. The estimated glomerular filtration rate was (85±34)ml/(min·1.73 m²) when the last investigation after kidney retransplantation with the kidney and patient all survived. Conclusions: Kidney retransplantation may have better prognosis in children. Dialysis transition during waiting period and DCD donor from 3 years of age or older can effectively ensure the success of kidney retransplantation.

[Adenocarcinomas with mesonephric features in gynecologic tract: a clinicopathological analysis of seven cases]

Objective: To investigate and compare the histologic characteristics of adenocarcinomas with mesonephric features located in different parts of the gynecologic tract. Methods: Two cases of mesonephric adenocarcinomas (MA) of the cervix and 5 cases of mesonephric-like adenocarcinomas (MLA) of the uterus and ovary were collected in Women's Hospital, School of Medicine, Zhejiang University from January 2018 to October 2020. Hematoxylin-eosin staining, immunohistochemistry and KRAS mutation testing were performed together with review of literature. Results: MA of the cervix as well as MLA of the uterus and ovary had similar morphologic features, showing an admixture of glandular, tubular, papillary and solid growth patterns. However, both MA cases were located in cervical stroma, which demonstrated residual mesonephric ducts present at the periphery. All four uterine MLA cases extensively involved the endometrium and myometrium. The ovarian MLA case was associated with endometriosis. No residual mesonephric ducts were present in the MLA cases. Immunohistochemically, GATA3 was positive in all seven MA/MLA cases. TTF1 was expressed only in 4/5 MLA cases. ER and PR were negative and p53 was wild-type in all cases. KRAS mutation was detected in all five cases. During the 6-32 months of follow-up, one patient developed recurrence and the others were tumor-free. Conclusions: In the gynecologic tract, both MA in cervix and MLA in uterus and ovary have similar morphologic features, immunohistochemical expression and KRAS mutation. However, distinct from MA that originates from mesonephric remnant, MLA is closely related to Mullerian epithelium.

[Advances in researches on neoadjuvant therapy for resectable colorectal liver metastasis]

Surgery is recognized as the core treatment for colorectal liver metastasis (CRLM), while its recurrence rate remains relatively high, even for resectable CRLM. This hints that the efficacy of treatment involves not only technological factors of surgery, but also biological behavior of tumor. For resectable CRLM, neoadjuvant therapy is beneficial to eliminate the micro-metastasis, reduce postoperative recurrence rate, screen tumor biological behavior and improve prognosis. However, questions about which kind of CRLM patients fits for neoadjuvant therapy and what regimen should be used are still debatable. This paper reviews stratified management of resectable CRLM, choice of neoadjuvant regimen, especially the application value of targeted therapy, based on the latest guidelines and studies.

[Laparoscopic radical resection of rectal cancer with preservation of the left colic artery: anatomical basis and surgical experience]

In order to increase the blood supply of anastomosis, surgeons choose to preserve the left colon artery (LCA) during the laparoscopic radical resection of rectal cancer. However, surgeons are always ailed by hemorrhage and incompletely dissection of No. 253 lymph nodes. One reason is the shortage of understanding the relationship between inferior mesenteric artery (IMA), LCA, and inferior mesenteric vein before surgery. Another reason is that surgeon always remove the lymph nodes around LCA, while don't normatively resect No. 253 lymph nodes, which affect the overall survival rate. Therefore, the "medial-to-lateral approach" for laparoscopic preservation with LCA radical resection in rectal cancer was suggested in this article. The CT technique could be used to analyze the IMA classification, which contribuated to the standard conservation of LCA. Laparoscopic radical resection of rectal cancer could be completed of high quality, through accurate definition and exactly dissection of the No. 235 lymph nodes.

[Vertical supraumbilical incision versus left lower oblique incision for specimen retrieval during laparoscopic rectal surgery]

Objective: To compared the short-term surgical outcomes of the vertical supraumbilical incision with the left lower oblique incision for specimen retrieval in laparoscopic resection for rectal cancer. Methods: A retrospective cohort study was performed. Inclusion criteria: (1) rectal cancer confirmed by colonoscopy and pathological examination; (2) undergoing the operation for the first time; (3) laparoscopic rectal surgery performed by the same surgeon team; (4) age of > 18 years and < 76 years old. According to above criteria, clinical data of 178 consecutive patients scheduled for laparoscopic surgery for rectal cancer at Department of Gastrointestinal Surgery of Renji Hospital between March 2015 and December 2017 were collected. Based on incision site of the mini-laparotomy, patients were classified to the vertical supraumbilical incision group (n=75) and the left lower oblique incision group (n=103). There were no significant differences in baseline data, such as age, gender, body mass index (BMI), tumor diameter, preoperative carcinoembryonic antigen (CEA) level, score of American Society of Anesthesiologists, TNM stage, between the two groups (all P>0.05). Perioperative variables and follow-up data were compared between two groups. Results: Between the vertical supraumbilical incision group and the left lower oblique incision group, the operation time [(131.7±3.7) minutes vs. (138.5±3.5) minutes], operative bleeding volume [(138.9±11.5) ml vs. (154.3±10.3) ml], length of auxiliary incision [(4.0±0.1) cm vs. (4.0±0.1) cm], and distance from anastomosis to dentate line [(3.8±0.1) cm vs. (4.2±0.1) cm] were not significantly different (all P>0.05). As compared to the left lower oblique incision group, patients in vertical supraumbilical incision group had earlier flatus [(62.7±2.3) hours vs. (69.2±1.7) hours, t=2.282, P=0.023], earlier ambulation [(41.9±1.8) hours vs. (46.78±1.42) hours, t=2.131, P=0.032], lower pain VAS scores at postoperative 24 hours (2.0±0.1 vs. 2.4±0.1, t=2.172, P=0.032) and 48 hours (2.7±0.1 vs. 3.0±0.1, P<0.05), and lower incidence of postoperative incisional hernia [6.7% (5/75) vs. 9.7% (10/103), χ(2)=3.942, P=0.042]. However, the postoperative fluids intake time, hospitalization days, pain VAS scores at postoperative 12 hours and postoperative complications (wound infection, anastomotic leakage, urinary retention, intestinal obstruction) were not significantly different between the two groups (all P>0.05). Conclusion: The vertical supraumbilical incision in laparoscopic resection for rectal cancer can reduce the degree of postoperative pain, facilitate early recovery of intestinal function and decrease the incidence of incisional hernia.

[HIV infection status and related factors in men who have sex with men in sentinel surveillance in Tianjin, 2016-2018]

Objective: To understand the HIV infection status and related factors in men who have sex with men (MSM) in Tianjin during 2016-2018. Methods: According to the sentinel surveillance protocol, continuous cross-sectional studies were conducted to collect the information about the awareness of AIDS, related behaviors, HIV infection, syphilis prevalence and HCV infection in the MSM in Tianjin with the annual sample seize of 400 between April and June during 2016-2018. Results: From 2016 to 2018, a total of 1 200 MSM were surveyed. The condom use rate in anal sex was 45.4% (544/1 198) in the past 6 months. The HIV test rate in MSM recruited through network declined with year (trend χ(2)=42.742, P<0.001). The overall HIV infection rate was 3.3% (40/1 200). The HIV-1 infection rate was 2.6% (95%CI: 1.7%-3.5%). The overall prevalence rate of syphilis was 6.7% (80/1 200). The overall HCV infection rate was 0.8% (9/1 200). Results from multivariate logistic regression analysis showed that the risk factors associated with HIV infection in the MSM included divorced or widowed (compared with unmarried, aOR=7.137, 95%CI: 1.621-31.419) and syphilis positive group (compared with syphilis negative group, aOR=3.684, 95%CI: 1.520-8.932). The protective factors for HIV infection in the MSM included consistent use of condom in the past 6 months (compared with occasional use of condom, aOR=0.343, 95%CI: 0.126-0.932) and HIV test (compared with receiving no HIV test, aOR=0.314, 95%CI: 0.123-0.801). Conclusions: The HIV infection rate in the MSM in Tianjin was high from 2016 to 2018. Syphilis prevalence status in MSM should not be neglected. The rate of consistent condom use in anal sex was low in the MSM. It is necessary to take effective measures to promote condom use and strengthen HIV test in MSM.

[Surveillance of potential transmission factors of schistosomiasis in Xiuzhou District of Jiaxing City from 2013 to 2015]

OBJECTIVE

To understand the potential risk of schistosomiasis transmission in Xiuzhou District of Jiaxing City, so as to provide the scientific evidence for consolidating schistosomiasis control achievements.

METHODS

Fixed and mobile surveillance sites were set up in Xiuzhou District of Jiaxing City from 2013 to 2015. Oncomelania hupensis snails was surveyed historical snail habitats, current snail habitats, and suspected snail habitats. The schistosome infections were identified using serological and parasitological testing among local residents and mobile populations. In addition, the survival and reproduction of snails imported into Xiuzhou District was observed, and the schistosome infection in wild reservoir hosts was detected.

RESULTS

A total of 540.14 hm² of settings were surveyed in Xiuzhou District, Jiaxing City from 2013 to 2015, and 1.65 hm² of snail habitats were identified. The snail habitats were mainly located in dry lands, and no infected snails or importation of snails were found. During the period from 2013 to 2015, a total of 7 668 local residents and mobile populations were examined in Xiuzhou District, and no new local infections were detected; however, three imported schistosomiasis cases were identified. Field simulation experiment showed that the imported snails laid eggs and reproduced in Xiuzhou District, and no schistosome infections were found in wild animals.

CONCLUSIONS

There are still residual Oncomelania snails and imported schistosomiasis patients in Xiuzhou District of Jiaxing City; therefore, the surveillance and management of local Oncomelania snails and imported schistosomiasis should be intensified to reduce the risk of schistosomiasis transmission.

[Evaluation on follow-up intervention program in men who have sex with men in Tianjin]

Objective: To evaluate the behavior intervention program on men who have sex with men (MSM) in Tianjin. Methods: From April 2013 to September 2017, MSM were enrolled from MSM gathering places and through mobile internet to establish an open prospective cohort. Interventions were conducted in every follow-up meeting, while the changes of behaviors and HIV infection and syphilis incidences in the MSM before and after intervention were compared. Results: A total of 1 822 MSM were interviewed at baseline survey, with 1 007 eligible MSM were enrolled in the cohort. A total of 39 new cases of HIV infection were reported, and the cumulative observation time on cohort follow-up was 2 216.96 person-year, with the HIV incidence rate as 1.76 per 100 person-years. Among them, 934 MSM were sero-negative for syphilis in baseline survey. A total of 100 new cases of syphilis were reported, and the cumulative observation time of cohort follow-up was 1 959.94 person-year, the syphilis incidence rate was 5.10 per 100 person-years. With health education and intervention conducted, the awareness rate of AIDS related knowledge for MSM increased. Though the rate of anal sex increased after intervention, the rate of condom use in anal sex increased, too. The rate of condom use decreased after receiving more than 3 interventions. Data from the multivariate GEE analysis indicated that protective factors might be as follows: education level of college and above (aOR=0.81, 95%CI: 0.68-0.98), awareness of AIDS related knowledge (aOR=0.52, 95%CI: 0.36-0.75), ever receiving condom promotion and distribution in the past six months (aOR=0.60, 95%CI: 0.49-0.74), being recruited from mobile internet (aOR=0.85, 95%CI: 0.73-1.00) and times of cumulative intervention: one time (aOR=0.55, 95%CI: 0.45-0.66), two times (aOR=0.38, 95%CI: 0.30-0.49), three times (aOR=0.26, 95%CI: 0.20-0.35), four times and above (aOR=0.24, 95%CI: 0.17-0.33). Diagnoses of STDs in the past six months (aOR=1.43, 95%CI: 1.06-1.96), using rush-poppers (aOR=1.22, 95%CI: 1.02-1.47) might be risk factors. Conclusions: After continuous behavior intervention, the incidence of HIV infection and syphilis were at a low level in the MSM cohort in Tianjin. Their awareness rate of AIDS related knowledge and the rate of condom use increased. But there are still many risk factors influencing the unprotected anal sex in MSM. We should continuously carry out behavioral intervention programs to prevent unprotected anal sex among MSM.

Towards high-energy, high-resolution computed tomography via a laser driven micro-spot gamma-ray source

Computed Tomography (CT) is a powerful method for non-destructive testing (NDT) and metrology awakes with expanding application fields. To improve the spatial resolution of high energy CT, a micro-spot gamma-ray source based on bremsstrahlung from a laser wakefield accelerator was developed. A high energy CT using the source was performed, which shows that the resolution of reconstruction can reach 100 μm at 10% contrast. Our proof-of-principle demonstration indicates that laser driven micro-spot gamma-ray sources provide a prospective way to increase the spatial resolution and toward to high energy micro CT. Due to the advantage in spatial resolution, laser based high energy CT represents a large potential for many NDT applications.

[Risk factors related to HIV new infections among men who have sex with men in a cohort study]

Objectives: To analyze and understand the risk factors related to HIV new infections among men who have sex with men (MSM). Methods: A longitudinal observational study among MSM was conducted to collect information on HIV related behaviors and sero-conversion. Univariate and multivariate generalized estimating equations (GEE) were used to discuss the risk factors for HIV new infection. Results: A total number of 4 305 MSM were followed during 2013-2015. Among those self-reported MSM who are seeking partners on the Interner tended to have higher proportion on receptive anal intercourse and consistent condom use during anal intercourse than the subgroups seeking their partners in gay bars or bathrooms. HIV incidence among followed MSM during the study period appeared as 4.3/100 person years, with adjusted RR (aRR) of HIV infection for receptive anal intercourse as group 2.20 (95% CI: 1.49-3.24) times than that of insertion anal intercourse group. Those who used rush-poppers (aRR=1.55, 95% CI: 1.10-2.17), unprotected anal intercourse (aRR=2.24, 95%CI: 1.62-3.08), and those with syphilis infection (aRR=2.95, 95%CI: 2.00-4.35) were also risk factors for HIV new infections. After controlling other factors, the relationship between the ways of seeking partners and HIV new infection was not statistical significant. Conclusion: Risk factors for HIV new infection among MSM appeared complex and interactive, suggesting that further studies are needed to generate tailored strategies for the prevention of HIV epidemic among MSM population.

[Factors associated with lost of follow-up of men who have sex with men in a gay bathhouse cohort study in Tianjin, 2012-2015]

Objective: To understand the rate of follow-up lost in men who have sex with men (MSM) in a gay bathhouse cohort study in Tianjin and the associated factors. Methods: The open cohort study in gay bathhouse was launched in 2012 in Tianjin, and the MSM for baseline survey were recruited from January to June 2012, while the follow up was carried out every six months. A questionnaire survey and HIV test were conducted in the study. The MSM who were HIV negative in the baseline survey in 2012 were used for follow up lost analysis. Univariate and multivariate logistic regression analysis were conducted to identify the factors associated with the lost of follow-up. Results: A total of 658 gay bathhouse patrons were recruited in the baseline survey, at the end of 42-month follow-up period, 173 of them dropped out (26.3%). Multivariate analysis showed that the MSM who were local residents (OR=0.552, 95%CI: 0.377-0.808), in Han ethnic group (OR=0.197, 95% CI: 0.066-0.593), having received HIV test in the last year (OR=0.481, 95% CI: 0.326-0.710), were male sex workers (OR=0.127, 95% CI: 0.028-0.585), and believed to be at high risk for HIV infection (OR=0.285, 95% CI: 0.125-0.647). They were more likely to receive follow-up but the MSM who were aged ≥35 years (OR=1.891, 95%CI: 1.022-3.500) were more likely to be lost in the follow-up. Conclusion: The lost rate of follow-up in MSM in the gay bathhouse cohort was high in Tianjin. Age, household registration, history of HIV test, the awareness of the risk to be infected with HIV and commercial homosex were factors associated with the follow-up rate in the MSM. It is necessary to conduct similar cohort study in targeted population on the basis of findings of this study.

[Meta-analysis on the positive rate of HIV among MSM with bathhouse as the major venue of sexual practice]

OBJECTIVE

To explore the positive rates on HIV among men who have sex with men (MSM) who took bathhouse as the major place for sexual practice in China, between 2010 and 2015.

METHODS

Articles published between 2010 and 2015 from CNKI, Wanfang Data, CJFD and PubMed were collected and Stata 12.0 software was used for Meta-analysis.

RESULTS

A total of 14 articles were selected. Random effects model was employed to calculate the pooled positive rate according to statistical tests for homogeneity with the result I(2)=88.1%. The pooled positive rate appeared as 10.3%, with 95%CI as 7.7%-13.0%. Publication bias was assessed by Egger' s test and funnel plot. After stratified analysis on factors as: sample size, year, region and methods on recruitment, the pooled positive rate of HIV appeared higher in people living in the coastal provinces than those in the inland provinces.

CONCLUSION

The pooled positive rate of HIV identified from the bathhouses appeared higher than that from other places through, the national HIV sentinel surveillance data, with coastal higher than that in the inland provinces. Bathhouse was recognized as the key place to be carried on intervention programs for the MSM population.

Amorphous cobalt hydroxide with superior pseudocapacitive performance

Cobalt hydroxide (Co(OH)2) has received extensive attention for its exceptional splendid electrical properties as a promising supercapacitor electrode material. Co(OH)2 study so far prefers to crystal instead of amorphous, in spite of amorphous impressive electrochemical properties including the ability to improve the electrochemical efficiency based on the disorder structure. The amorphous Co(OH)2 nanostructures with excellent electrochemical behaviors were successfully synthesized by a simple and green electrochemistry. Our as-prepared Co(OH)2 electrode exhibited ultrahigh capacitance of 1094 F g(-1) and super long cycle life of 95% retention over 8000 cycle numbers at a nominal 100 mV s(-1) scan rate. The united pseudo-capacitive performances of the amorphous Co(OH)2 nanostructures in electrochemical capacitors are totally comparable to those of the crystalline Co(OH)2 nanomaterials. These findings actually open a door to applications of amorphous nanomaterials in the field of energy storage as superior electrochemical pseudocapacitors materials.

Chemotherapy with low-dose bevacizumab and carboplatin in the treatment of a patient with recurrent cervical cancer

Management of patients with recurrent or advanced cervical cancer is a challenge. Concurrent chemotherapy has become the mainstay of treatment and platinum remains the most effective single agent. Combinations of other agents have not demonstrated significant advantages. The application of angiogenesis inhibitors such as bevacizumab, an antibody inhibiting vascular endothelial growth factor, in metastatic or advanced cervical cancer remains to be evaluated. We present the case of a patient with platinum-resistant recurrent cervical cancer treated with low-dose bevacizumab and carboplatin, with resultant improved disease progression and tolerable toxicity profiles.

Role of the connectivity of secondary structure segments in the folding of alpha(1)-antitrypsin

The native form of serpins (serine protease inhibitors) is metastable, which is critical to their biological functions. Spontaneous conversion from the native form of serpins into a more stable conformation, called the "latent" form, is restricted. To examine whether the connectivity of strand 1 of beta-sheet C to the hydrophobic core is critical to the serpin's preferential folding to the metastable native conformation, we designed a circularly-permuted mutant of alpha(1)-antitrypsin, the prototype serpin, in which strand 1C is disconnected from the hydrophobic core. Conformation of the circular permutant was similar to that of the latent form, as revealed by equilibrium unfolding, limited proteolysis, and spectroscopic properties. Our results support the notion that rapid folding of the hydrophobic core with concomitant incorporation of strand 1C into beta-sheet C traps the serpin molecule into its native metastable conformation.

Cavities of alpha(1)-antitrypsin that play structural and functional roles

The native form of inhibitory serine protease inhibitors (serpins) is strained, which is critical for their inhibitory activity. Previous studies on stabilizing mutations of alpha(1)-antitrypsin, a prototype of serpins, indicated that cavities provide a structural basis for the native strain of the molecule. We have systematically mapped the cavities of alpha(1)-antitrypsin that play such structural and functional roles by designing cavity-filling mutations at residues that line the walls of the cavities. Results show that energetically unfavorable cavities are distributed throughout the alpha(1)-antitrypsin molecule, and the cavity-filling mutations stabilized the native conformation at 8 out of 10 target sites. The stabilization effect of the individual cavity-filling mutations of alpha(1)-antitrypsin varied (0.2-1.9 kcal/mol for each additional methylene group) and appeared to depend largely on the structural flexibility of the cavity environment. Cavity-filling mutations that decreased inhibitory activity of alpha(1)-antitrypsin were localized in the loop regions that interact with beta-sheet A distal from the reactive center loop. The results are consistent with the notion that beta-sheet A and the structure around it mobilize when alpha(1)-antitrypsin forms a complex with a target protease.

Elevated topoisomerase I activity in cervical cancer as a target for chemoradiation therapy

OBJECTIVE

The aim of this study was to determine whether the activity of topoisomerase I (topo I), the target of the anti-neoplastic drug camptothecin (CPT), is elevated in cervical cancer and whether CPT can radiosensitize cervical tumors.

METHODS

The topo I activity of 11 normal cervix and 30 cervical carcinoma tumors was assayed by measuring the relaxation of supercoiled DNA. Subconfluent or postconfluent CaSki human cervical carcinoma cells were exposed to CPT (1-5000 ng/ml) and immediately X-irradiated (0-800 cGy). Cell survival was determined by clonogenic assay.

RESULTS

Mean topo I activity in cervical cancer (3.0 +/- 0.06 h(-1)) was significantly greater than in normal cervix tissue (0.29 +/- 0.06 h(-1)). Stage 3 and 4 cervical carcinoma specimens displayed a trend of greater topo I activity (5.88 +/- 3.7 h(-1)) than stage 1 and 2 tumors (2.57 +/- 0.47 h(-1)). No correlation between topo I protein levels and catalytic activity was found. Combined treatment of subconfluent CaSki cells with CPT and ionizing radiation resulted in additive killing of cells. Combined treatment of postconfluent CaSki cells with low doses of radiation (200 and 400 cGy) and 1 or 10 ng/ml CPT for 2 or 48 h produced significant cytotoxicity compared to CPT or radiation alone, which were ineffective at these doses.

CONCLUSIONS

Topo I activity is elevated in cervical cancer compared to normal cervix. The radiosensitivity of noncycling cells within cervical tumors may be increased by simultaneous treatment with low doses of CPT or other topo I inhibitors.

Effects of treatment of secondary hyperparathyroidism on the lipid profile in patients on hemodialysis

Abnormalities in circulating lipoprotein concentrations are a characteristic finding in patients undergoing dialytic therapy. A substantial number of these patients display type IV hyperlipoproteinemia. Certain data suggest that secondary hyperparathyroidism may induce disturbances in lipid metabolism. To evaluate the effects of pulse calcitriol therapy on the lipid profile in these patients, we undertook a prospective study in 12 patients on stable bicarbonate hemodialysis. Lipid parameters comprising cholesterol and the low- as well as the high-density lipoprotein subfractions, triglycerides, apolipoproteins A and B, serum parathyroid hormones (iPTH), alkaline phosphatase, calcium, phosphorus, hematocrit, and blood urea were obtained prior to commencement of pulse calcitriol therapy and again 8-10 weeks later. Calcitriol therapy was associated with a decrease in serum iPTH levels (701 +/- 103.9 vs. 220.3 +/- 50.5 pmol/l; p < 0.001). Significant increases in high-density lipoprotein cholesterol (32.8 +/- 2.7 vs. 38.8 +/- 2.3 mmol/l; p < 0.05) and apolipoprotein A-I (107.8 +/- 6.1 vs. 121.8 +/- 5.8 g/l; p < 0.05) were noted during the course of the study. Moreover, serum iPTH correlated inversely with high-density lipoprotein cholesterol and apolipoprotein A-I. There were no changes in other lipid parameters except for low-density lipoprotein cholesterol which showed a tendency to increase. We conclude that in short-term study, pulse oral calcitriol therapy is associated with an improvement in the lipid profile in patients with secondary hyperparathyroidism. However, it remains to be established whether ameliorating the uremic dyslipidemia results in any long-term clinical benefits.

Verrucous carcinoma of the uterine cervix

Verrucous carcinoma is a variant of squamous cell carcinoma that is often found in the oral cavity, skin and larynx. It rarely occurs in the genital tract, especially in the cervix. A 66-year-old postmenopausal female had undergone a total abdominal hysterectomy and bilateral salpingo-oophorectomy at a local hospital 1 year previously, due to carcinoma in situ of the cervix. The patient complained of profuse discharge from the vagina. Under the impression of chronic inflammation and suspicion of cancer recurrence, the patient was transferred to the Tri-Service General Hospital. A pelvic examination revealed a cauliflower-like, fungating mass about 4 cm in diameter located in the anterior vaginal vault. A biopsy disclosed verrucous carcinoma. Cystoscopy with bladder biopsy also confirmed direct tumor invasion into the bladder trigone. Anterior exenteration was performed including radical cystectomy, ileal conduit, vaginectomy, bilateral pelvic lymph node dissection and appendectomy. The final pathology report was verrucous carcinoma with bladder invasion. The margins of the ureters and vaginal cutting end were free of cancerous cells. Surgical excision is the treatment of choice for verrucous carcinoma. Radiotherapy is contraindicated because it may induce anaplastic transformation with subsequent regional and distant metastasis. Further surgical excision, even exenteration, is required for recurrent tumors.

Effects of temperature on radiochemical purity and immunoreactivity of radiolabeled monoclonal antibody 1H10

OBJECTIVE

This study was undertaken to investigate the effects of temperature on preserving the radiochemical purity and immunoreactivity of 125I- and 131I-labeled monoclonal antibody (MAb) 1H10--an antibody against human cervical carcinoma cell-surface antigen.

METHODS

An antibody-irrelevant human melanoma cell line, H2269, served as the control group. Iodine-125 and 131I radiolabeling of MAbs 1H10 and H2669 was performed by the chloramine-T method. All the prepared MAbs were divided into aliquots and stored at 4, -20, and -70 degrees C for 2-14 d. The radiochemical purity and immunoreactivity of the labeled antibodies in set conditions were measured by thin-layer chromatography and a modified index, respectively, after a single freeze-and-thaw cycle.

RESULTS

Reduced release of free radioiodide and better preservation of immunoreactivity were observed in the radiolabeled MAbs stored at -70 degrees C than in those stored at -20 degrees C or 4 degrees C. The extent of free iodide dissociation and immunologic binding degradation of 125I-labeled MAb 1H10 appeared milder than that of 131I-labeled MAb under the same conditions. However, both 125I- and 131I-labeled MAb stored at -70 degrees C or -20 degrees C retained more than 90% radiochemical purity for at least 3d.

CONCLUSION

Freezing provides an appropriate alternative for reducing radiolysis and preserving immunoreactivity of radioiodinated MAbs. MAb 1H10, labeled with either 125I or 131I and stored at temperatures of -20 degrees C or below for 3 d after labeling, appeared stable in both radiolabeling and binding studies in vitro and was still acceptable for in vivo use.

[Determination of nitrite and nitrate in rat nervi ischiadicus by high performance liquid chromatography]

To study the effect of nitric oxide on the diabetic neuropathy, a quantitative method for the determination of nitrite(NO2-) and nitrate(NO3-) in rat nervi ischiadicus by high performance liquid chromatography(HPLC) with UV-VIS detection was developed. In the range of 1 mumol/L-25 mumol/L, correlation coefficient between concentration and peak area for NO2- and NO3- was more than 0.991. The minimum detection limits for both ions were 0.2 mumol/L and 0.5 mumol/L, respectively. Relative standard deviation(RSD) of inter-day and intra-day was less than 14%. The effects of different acetonitrile concentration and pH of mobile phase on separation as well as the stability of both salty ions were studied. In comparison with normal group, the levels of NO2- and NO3- for diabetic groups were lower. Measured mean values were, in turn, as follows: normal rats, (2.62 +/- 0.38) mumol/L and (24.43 +/- 5.61) mumol/L (n = 8); diabetic-controlled rats (saline-given only), (2.24 +/- 0.20) mumol/L and (17.15 +/- 7.79) mumol/L (n = 6); diabetic rats treated with bovine colostrum insulin-like growth factor(BctIGF-1) or with recombinant human insulin-like growth factor (rhIGF-1), (2.55 +/- 0.36) mumol/L and (6.12 +/- 2.14) mumol/L (n = 5) and (1.46 +/- 0.08) mumol/L and (9.95 +/- 3.34) mumol/L (n = 7), respectively.

Bypassing the kinetic trap of serpin protein folding by loop extension

The native form of some proteins such as strained plasma serpins (serine protease inhibitors) and the spring-loaded viral membrane fusion proteins are in a metastable state. The metastable native form is thought to be a folding intermediate in which conversion into the most stable state is blocked by a very high kinetic barrier. In an effort to understand how the spontaneous conversion of the metastable native form into the most stable state is prevented, we designed mutations of alpha1-antitrypsin, a prototype serpin, which can bypass the folding barrier. Extending the reactive center loop of alpha1-antitrypsin converts the molecule into a more stable state. Remarkably, a 30-residue loop extension allows conversion into an extremely stable state, which is comparable to the relaxed cleaved form. Biochemical data strongly suggest that the strain release is due to the insertion of the reactive center loop into the major beta-sheet, A sheet, as in the known stable conformations of serpins. Our results clearly show that extending the reactive center loop is sufficient to bypass the folding barrier of alpha1-antitrypsin and suggest that the constrain held by polypeptide connection prevents the conversion of the native form into the lowest energy state.

Regulation of protein function by native metastability

In common globular proteins, the native form is in its most stable state. In contrast, each native form exists in a metastable state in inhibitory serpins (serine protease inhibitors) and some viral membrane fusion proteins. Metastability in these proteins is critical to their biological functions. Mutational analyses and structural examination have previously revealed unusual interactions, such as side-chain overpacking, buried polar groups, and cavities as the structural basis of the native metastability. However, the mechanism by which these structural defects regulate protein functions has not been elucidated. We report here characterization of cavity-filling mutations of alpha(1)-antitrypsin, a prototype serpin. Conformational stability of the molecule increased linearly with the van der Waals volume of the side chains. Increasing conformational stability is correlated with decreasing inhibitory activity. Moreover, the activity loss appears to correlate with the decrease in the rate of the conformational switch during complex formation with a target protease. These results strongly suggest that the native metastability of proteins is indeed a structural design that regulates protein functions.

Distribution of the native strain in human alpha 1-antitrypsin and its association with protease inhibitor function

Serine protease inhibitors (serpins) are metastable in their native state. This strain, which is released upon binding to target proteases, is essential for the inhibitory activity of serpins. To understand the structural basis of the native strain, we previously characterized stabilizing mutations of alpha(1)-antitrypsin, a prototypical inhibitory serpin, in regions such as the hydrophobic core. The present study evaluates the effects of single point mutations throughout the molecule on stability and protease inhibitory activity. We identified stabilizing mutations in most secondary structures, suggesting that the native strain is distributed throughout the molecule. Examination of the substitution patterns and the structures of the mutation sites revealed surface hydrophobic pockets as a component of the native strain in alpha(1)-antitrypsin, in addition to the previously identified unusual interactions such as side chain overpacking and cavities. Interestingly, many of the stabilizing substitutions did not affect the inhibitory activity significantly. Those that affected the activity were confined in the regions that are mobilized during the complex formation with a target enzyme. The results of our study should be useful for designing proteins with strain and for regulating the stability and functions of serpins.

Role of Lys335 in the metastability and function of inhibitory serpins

The native form of inhibitory serpins (serine protease inhibitors) is not in the thermodynamically most stable state but in a metastable state, which is critical to inhibitory functions. To understand structural basis and functional roles of the native metastability of inhibitory serpins, we have been characterizing stabilizing mutations of human alpha1-antitrypsin, a prototype inhibitory serpin. One of the sites that has been shown to be critical in stability and inhibitory activity of alpha1-antitrypsin is Lys335. In the present study, detailed roles of this lysine were analyzed by assessing the effects of 13 different amino acid substitutions. Results suggest that size and architect of the side chains at the 335 site determine the metastability of alpha1-antitrypsin. Moreover, factors such as polarity and flexibility of the side chain at this site, in addition to the metastability, seem to be critical for the inhibitory activity. Substitutions of the lysine at equivalent positions in two other inhibitory serpins, human alpha1-antichymotrypsin and human antithrombin III, also increased stability and decreased inhibitory activity toward alpha-chymotrypsin and thrombin, respectively. These results and characteristics of lysine side chain, such as flexibility, polarity, and the energetic cost upon burial, suggest that this lysine is one of the structural designs in regulating metastability and function of inhibitory serpins in general.

Favorable clinical outcome of cervical cancers infected with human papilloma virus type 58 and related types

To determine whether the status of human-papillomavirus (HPV) infection affects the clinical outcome of cervical carcinoma (CC), HPV genotype was prospectively determined in 94 consecutive CC cases subsequently followed for a median duration of 37.5 months. With a consensus PCR-RFLP method of HPV genotyping, 81 (86.2%) cancers were positive for HPV DNA. They were classified, according to the phylogenic similarities, into HPV-16-related (type 16, n = 45; type 31, n = 2), HPV-58-related (type 58, n = 17; type 33, n = 3; type 52, n = 2) and HPV-18-related (type 18, n = 8; type 68, n = 1) groups, and analyzed in relation to clinical outcome. The following results were observed: (i) Type-58-related HPVs were more prevalent in the old age (older than the median age of 52) group than in the young age group (41% vs. 14.6%, p = 0.045); (ii) 63% (5/8) of patients with advanced stages (III and IV) were HPV-negative, a figure much higher than that (9.3%, 8/84) of patients with early stages (stage I and II) (p = 0.002); (iii) the occurrence of adenocarcinoma or adenosquamous carcinoma was higher in the HPV-18-related group (50%) than in the HPV-16-related (33.3%) or the HPV-58-related (16.7%) groups (p = 0.024); (iv) the status of lymph-node metastasis and tumor grade did not correlate with HPV status; (v) 5-year survival rates were 90.2%, 80% and 74% for HPV-58-, HPV-16- and HPV-18-related groups, respectively (p = 0.03, after adjustment for tumor stage); (vi) in comparison with the HPV-16-related group, the relative risk of death in the HPV-58- and the HPV-18-related groups were 0.32 [95% CI, 0.07-1.49] and 1.87 [0.36-14.9] respectively. HPV genotype appears to affect the clinical behavior and outcome of cervical cancer. HPV-58-related types are prevalent in the older population, and appear to confer a favorable prognosis. Int. J. Cancer (Pred. Oncol.) 84:553-557, 1999.

Fetal mouse selenophosphate synthetase 2 (SPS2): biological activities of mutant forms in Escherichia coli

A novel gene, sps2, detected in mouse embryo at the early stages of development has been identified as an analog of the E. coli selenophosphate synthetase gene. Unlike the E. coli enzyme, the presence of selenocysteine in the mouse enzyme is indicated by a TGA codon in the open reading frame of the cDNA. Using an N-FLAG monoclonal antibody, it was shown that the full length N-FLAG-sps2 gene product was expressed in COS-7 cells. To investigate the biological activity of the sps2 gene product in vivo, the mutated sps2 gene, which contains cysteine in the place of the TGA encoded selenocysteine in the wild type, was expressed in the E. coli selD deficient mutant, MB08. Like the E. coli wild type selD gene, the mutant sps2 gene complemented the selD mutation. However, replacement of Cys with either Ala, Ser, or Thr resulted in a loss of ability to complement the selD mutation. The SPS2-CYS protein expressed in E. coli was purified and its catalytic activity was determined. The Km value for ATP was 0.75 mM and Vmax was 9.23 nmole/min/mg protein. These results confirm that the mouse embryonic sps2 gene encodes an eukaryotic selenophosphate synthetase, and that availability of selenophosphate as a selenium donor compound is widespread.

Metastability in the inhibitory mechanism of human alpha1-antitrypsin

Metastability of the native form of proteins has been recognized as a mechanism of biological regulation. The energy-loaded structure of the fusion protein of influenza virus and the strained native structure of serpins (serine protease inhibitors) are typical examples. To understand the structural basis and functional role of the native metastability of inhibitory serpins, we characterized stabilizing mutations of alpha1-antitrypsin in a region presumably involved in complex formation with a target protease. We found various unfavorable interactions such as overpacking of side chains, polar-nonpolar interactions, and cavities as the structural basis of the native metastability. For several stabilizing mutations, there was a concomitant decrease in the inhibitory activity. Remarkably, some substitutions at Lys-335 increased the stability over 6 kcal mol-1 with simultaneous loss of activity over 30% toward porcine pancreatic elastase. Considering the location and energetic cost of Lys-335, we propose that this lysine plays a pivotal role in conformational switch during complex formation. Our current results are quite contradictory to those of previously reported hydrophobic core mutations, which increased the stability up to 9 kcal mol-1 without any significant loss of activity. It appears that the local strain of inhibitory serpins is critical for the inhibitory activity.

Intracervical misoprostol as an effective method of labor induction at term

OBJECTS

The purpose of this study was to evaluate the safety and effectiveness of intracervical misoprostol for the induction of labor at term.

METHODS

Eighty-nine term pregnancies requiring induction of labor were treated intracervically with 50 microg of misoprostol. The dose was repeated every 4 h until adequate uterine contraction and cervical dilatation were achieved. Status of cervical ripening, uterine contraction, cervical dilatation, labor course and side effects were recorded and analyzed.

RESULTS

Among the 89 patients, 58 had an unfavorable cervix (Bishop score < or = 4) and 31 had a favorable cervix (Bishop score > 4). Labor was successfully induced in all cases, most (93.3%) of which required a single dose of misoprostol. Seventy-two patients (81%) proceeded to spontaneous vaginal delivery, and 61 (85%) deliveries were achieved within 12 h. The other 17 cases received cesarean delivery with indications of fetopelvic disproportion (six cases), failure of induction (seven cases) and acute fetal distress (four cases). The mean duration from induction to regular uterine contraction and to delivery was 483+/-537 min and 79.2+/-38.2 min, respectively, with no significant difference between the two groups with differing status of cervical ripening. Complications of uterine contraction, including tachysystole (15 cases), hypertonus (one case) and hyperstimulation (10 cases) were more common in the group of unfavorable cervix (45%) than that of favorable cervix (23%) (P < 0.05).

CONCLUSION

In addition to the oral and intravaginal routes of administration, intracervical misoprostol at a single dose of 50 microg appears to be an effective method for induction of labor at term, but caution should be taken with cases with unfavorable cervix.

Extra-amniotic balloon with PGE2 versus extra-ovular Foley catheter with PGF2alpha in mid-trimester pregnancy termination

OBJECTIVE

The objective of this study was to compare the efficacy and side effects of two methods of mid-trimester labor induction, extra-amniotic balloon with intracervical prostaglandin (PG) E2 (0.5 mg x 2) vs. extra-ovular Foley catheter with intrauterine PGF2alpha (1 mg/h x6).

METHODS

A cohort of 32 and 36 cases indicated for mid-trimester termination was enrolled and managed with extra-amniotic balloon and extra-ovular Foley catheter methods, respectively. Outcomes of induction-to-delivery interval, induction failure, and occurrence of side effects were assessed.

RESULTS

There were no statistical differences in maternal age, parity, gestational age or fetal birth weight between the two groups. Compared with the extra-ovular Foley catheter with PGF2alpha group, the induction-to-delivery interval was significantly shorter in the extra-amniotic balloon plus PGE2 group. There was no significant difference in side effects and major complications developed in either groups.

CONCLUSIONS

The extra-amniotic balloon with intracervical PGE2 is more efficient in reducing the induction-to-delivery interval for termination of mid-trimester pregnancies than the extra-ovular Foley catheter with intrauterine PGF2alpha.

Thromboxane and prostacyclin in maternal and fetal circulation in pre-eclampsia

OBJECTIVES

A major pathophysiologic change of pre-eclampsia has been attributed to the overproduction of thromboxane A2 (TXA2) mainly from activated platelets. On the other hand, increased biosynthesis of TXA2 has also been reported from preeclamptic placentas. The systemic role of these different sources of TXA2 has not been clarified. The purpose of this study is to define the changes of TXA2 and the antagonizing prostacyclin (PC) in maternal and fetal circulations.

METHODS

The stable metabolites of TXA2 and PC [Thromboxine B2 (TXB2) and 6-keto-prostaglandin F1alpha (6-keto-PGF1alpha), respectively] in the cord and maternal blood of nine patients with pre-eclampsia and nine normal parturients were measured by radioimmunoassay.

RESULT

In normal pregnancy, the cord blood contained much higher TXB2 (1697+/-898 vs. 267+/-128 ng/ml, P < 0.01) and 6-keto-PGF1alpha (266+/-263 vs. 12.5+/-3.9 ng/ml, P < 0.05) levels than the maternal blood. In the preeclamptic state, a marked increase of TXB2 was noted in both maternal and cord blood, reaching levels which were significantly higher than during normal pregnancy (2995+/-1103 vs. 267+/-128 ng/ml in maternal blood, P < 0.0001, and 3197+/-1288 vs. 1697+/-898 ng/ml in cord blood, P < 0.005). A less significant increase in 6-keto-PGF1alpha (134+/-10.8 vs. 12.5+/-3.9 ng/ml, P < 0.05) was also noted in the maternal blood. Moreover, the level of TXB2 correlated with the diastolic blood pressure of preeclamptic patients before and after delivery.

CONCLUSION

The results suggest an abundant source of eicosanoids in the feto-placental circulation, which does not readily cross the placental barrier. In pregnancy complicated with pre-eclampsia, thromboxane level of both fetal and maternal circulations are markedly increased, which may be responsible for the pathophysiologic changes. The lack of adverse systemic effects on the fetus highlights a placental source of TXA2 of transient bioactivity which is rapidly hydrolyzed to non-active TXB2. Federation of Gynecology and Obstetrics

Homology modeling of the receptor binding domain of human thrombopoietin

Platelet production in blood is regulated by a lineage specific humoral factor, thrombopoietin (TPO). The amino terminal domain of TPO (TPO-N) is responsible for the signal transduction mediated by the TPO receptor, c-mpl. From the predicted length of helices we found that TPO-N belongs to the long-chain subfamily of the four-helix bundle cytokine family. We built a three dimensional model of TPO-N by a comparative homology modeling procedure. The four helices of TPO-N with an up-up-down-down topology are stabilized by a tightly packed central hydrophobic core and the extended loop AB makes an additional hydrophobic core with helices B and D outside of the four helix bundle scaffold. An interpretation of the previous site directed mutageneses results in light of the model enabled us to identify two isolated receptor binding sites. The surface made of Lys 136, Lys 138 and Lys 140 in helix D, and Pro 42 and Glu 50 in loop AB forms the first receptor binding site, while the surface of Asp 8, Arg 10 and Lys 14 in helix A represents the second binding site for the sequential receptor oligomerization.

Glycosylation of human alpha 1-antitrypsin in Saccharomyces cerevisiae and methylotrophic yeasts

Human alpha 1-antitrypsin (alpha 1-AT) is a major serine protease inhibitor in plasma, secreted as a glycoprotein with a complex type of carbohydrate at three asparagine residues. To study glycosylation of heterologous proteins in yeast, we investigated the glycosylation pattern of the human alpha 1-AT secreted in the baker's yeast Saccharomyces cerevisiae and in the methylotrophic yeasts, Hansenula polymorpha and Pichia pastoris. The partial digestion of the recombinant alpha 1-AT with endoglycosidase H and the expression in the mnn9 deletion mutant of S. cerevisiae showed that the recombinant alpha 1-AT secreted in S. cerevisiae was heterogeneous, consisting of molecules containing core carbohydrates on either two or all three asparagine residues. Besides the core carbohydrates, variable numbers of mannose outer chains were also added to some of the secreted alpha 1-AT. The human alpha 1-AT secreted in both methylotrophic yeasts was also heterogeneous and hypermannosylated as observed in S. cerevisiae, although the overall length of mannose outer chains of alpha 1-AT in the methylotrophic yeasts appeared to be relatively shorter than those of alpha 1-AT in S. cerevisiae. The alpha 1-AT secreted from both methylotrophic yeasts retained its biological activity as an elastase inhibitor comparable to that of alpha 1-AT from S. cerevisiae, suggesting that the different glycosylation profile does not affect the in vitro activity of the protein.

Characterization of a human alpha1-antitrypsin variant that is as stable as ovalbumin

The metastability of inhibitory serpins (serine proteinase inhibitors) is thought to play a key role in the facile conformational switch and the insertion of the reactive center loop into the central beta-sheet, A-sheet, during the formation of a stable complex between a serpin and its target proteinase. We have examined the folding and inhibitory activity of a very stable variant of human alpha1-antitrypsin, a prototype inhibitory serpin. A combination of seven stabilizing single amino acid substitutions of alpha1-antitrypsin, designated Multi-7, increased the midpoint of the unfolding transition to almost that of ovalbumin, a non-inhibitory but more stable serpin. Compared with the wild-type alpha1-antitrypsin, Multi-7 retarded the opening of A-sheet significantly, as revealed by the retarded unfolding and latency conversion of the native state. Surprisingly, Multi-7 alpha1-antitrypsin could form a stable complex with a target elastase with the same kinetic parameters and the stoichiometry of inhibition as the wild type, indicating that enhanced A-sheet closure conferred by Multi-7 does not affect the complex formation. It may be that the stability increase of Multi-7 alpha1-antitrypsin is not sufficient to influence the rate of loop insertion during the complex formation.

Identification of functionally important residues of human thrombopoietin

Thrombopoietin (TPO) is a megakaryocyte growth and differentiation factor. It consists of a characteristic two domain structure. The amino-terminal domain of TPO has a sequence homology with erythropoietin and is required for the binding and activation of its receptor c-Mpl. To determine the functionally important regions interacting with its receptor, a series of site-directed mutants of TPO were constructed based on a three-dimensional model of the amino-terminal domain. Two strategies of mutagenesis were employed: 1) nonnative N-linked glycosylation scan of 12 residues predicted to be on the surface, and 2) alanine replacement scan of mostly charged 44 amino acid residues. Each TPO mutein was transiently expressed in COS7 cells, and the specific bioactivity of the TPO protein secreted into the culture medium was measured using a recombinant BaF3 cell line expressing human c-Mpl. Four alanine substitutions at Arg10, Pro42, Glu50, and Lys138 nearly or completely abolished the activity, whereas the mutation at Arg14 slightly decreased the activity, suggesting that these residues are functionally important in interacting with its receptor. These residues mapped to helix A, loop AB, and helix D. Sequence comparison between human TPO and other mammalian TPO showed that the identified residues are completely conserved among the species. However, unlike the recent report on the mutational analysis of TPO, alanine substitutions at Lys52, Lys59, Arg136, and Arg140 did not affect the TPO activity significantly in our system. The identified receptor binding regions of TPO are analogous to those of human growth hormone and erythropoietin. Based on the similarity of these three cytokines, we propose that Lys138 of helix D and Pro42 and Glu50 of loop AB may constitute one binding region, whereas Arg10 and Lys14 of helix A may constitute the other binding region to dimerize the receptors.

Second and early third trimester pregnancy termination by extra-amniotic balloon and intracervical PGE2

OBJECTIVE

The aim of the study was to investigate the efficacy and safety of an alternative modality using extra-amniotic balloon and intracervical prostaglandin (PG) E2 for termination of second and early third trimester pregnancies.

METHOD

Thirty-three pregnant women scheduled for legal termination of pregnancy at 15-32 weeks' gestation were included in the study. Each case received extra-amniotic balloon containing 500-800 ml normal saline and two PGE2 tablets inserted into the cervical canal.

RESULTS

All 33 patients achieved a successful termination. The mean induction-to-abortion interval was 12.85 h. There was no significant difference in induction-to-abortion interval between second trimester group and third trimester group. However, the mean duration of balloon distention was longer in the second trimester group. There were no severe complications.

CONCLUSION

The combined use of extra-amniotic balloon and intracervical PGE2 tablets is effective, safe and convenient for termination of second and early third trimester pregnancy.

Repression participates in mammary tissue-specific activation of the caprine beta-lactoglobulin promoter

Activation of the beta-lactoglobulin (BLG) gene promoter is restricted to overtly differentiated mammary tissue. To understand the mechanism underlying such tissue-specificity, activity of the caprine BLG promoter was analyzed comparatively in cultured mammary HC11 cells and non-mammary HeLa and CV-1 cells. The BLG promoter flanked by the 5'-regulatory sequence below -205 was strongly activated in the cells, regardless of the cell type. In non-mammary HeLa and CV-1 cells, this activation was repressed completely by the upper regulatory sequence. Weak repression was also observed in mammary HC11 cells kept non-confluent. As the mammary HC11 cells grew confluent and maintained the stabilized state, however, repression by the upper regulatory sequence was switched to activation. The repressive upstream flanking sequence was strongly recognized by the binding factors in non-mammary HeLa and CV-1 cells in an in vitro binding assay. Binding intensity and competition strength of the upstream regulatory regions were in a close correlation to their transcriptional repression activities in the cultured cells. The results suggest that the restricted activation of the caprine BLG promoter in differentiated mammary tissue is guaranteed by repression in non-mammary and undifferentiated mammary cells.

Effect of glycosylation on the stability of alpha1-antitrypsin toward urea denaturation and thermal deactivation

The effects of glycosylation on the stability of human alpha1-antitrypsin were investigated. The transition midpoints in urea-induced equilibrium unfolding of a non-glycosylated recombinant, a yeast version of glycosylated, and human plasma alpha1-antitrypsin were 1.8 M, 2.2 M, and 2.5 M at 25 degrees C, respectively. Kinetic analyses of unfolding and refolding revealed that glycosylation retarded the unfolding without affecting the refolding rate significantly, suggesting that the stability increase is due to the stabilization of the native state as opposed to the destabilization of the unfolded state. In thermal deactivation, which is a heat-induced aggregation process, the unglycosylated recombinant alpha1-antitrypsin was deactivated most easily, which was followed in order by the yeast, and the plasma form. The results indicate that glycosylation confers the increase in stability of alpha1-antitrypsin, and that the oligomannose sugars present on the yeast form produce a less stable molecule than the complex type sugars on the plasma form. It appears that the effect of glycosylation on the enhancement of thermal resistance is exerted through the increase in conformational stability. However, a stable recombinant variant (Phe 51 --> Cys) that showed the same conformational stability as the plasma form was less resistant to thermal denaturation than the plasma alpha1-antitrypsin. The results suggest that the existence of carbohydrate moiety per se as well as the conformational stability contribute to the kinetic stability of alpha1-antitrypsin toward aggregation.