[Prevalence of syphilis in HIV-infected patients with transmission risk and influencing factors in Zhejiang Province].

Objective: To investigate the prevalence of syphilis in HIV-infected patients with transmission risk and influencing factors in Zhejiang Province. Method: The information about the HIV-infected patients, who were alive, had been diagnosed with HIV for >1 year, had received no antiviral treatment or had HIV viral load ≥50 copies/ml, and were aged ≥15 years, reported in Zhejiang as of December 31, 2018 were collected from China Information System for Disease Control and Prevention. The information included general demographic characteristics, sexual behavior characteristics and antiretroviral therapy and syphilis serological test results. The prevalence of syphilis and the influencing factors were analyzed by logistic regression model. The SPSS 19.0 software was used for statistical analysis. Results: A total of 2 275 HIV-infected patients were at risk of HIV transmission, and 75.5% (1 717/2 275) of them were tested for syphilis, the prevalence rate of syphilis was 8.7% (150/1 717). Among the HIV-infected patients with syphilis, 11.3% (17/150) received no antiviral treatment, 38.7% (58/150) had viral load of 50-999 copies/ml and 50.0% (75/150) had ≥1 000 copies/ml. Multivariate logistic regression analysis showed that being men (aOR=2.04, 95%CI:1.06-3.96), homosexual transmission (aOR=1.53, 95%CI:1.04-2.27), history of sexually transmitted diseases (STDs) before HIV diagnosis (aOR=1.98, 95%CI:1.35-2.92) and HIV viral load ≥1 000 copies/ml (aOR=1.90, 95%CI:1.09-3.30) were the risk factors for syphilis. Marriage (aOR=0.47, 95%CI: 0.29-0.76) was a protective factor for syphilis. Conclusions: The prevalence of syphilis was high in HIV-infected patients with transmission risk in Zhejiang. It is urgent to carry out classified management and targeted intervention in HIV-infected patients, explore multi-disease prevention and treatment mechanism, strengthen syphilis screening and treatment in HIV-infected patients to reduce the transmission of HIV and syphilis.

[Reinforced radiculoplasty for the treatment of symptomatic sacral Tarlov cysts: A clinical analysis of 71 cases].

OBJECTIVE: To investigate the safety and efficacy of reinforced radiculoplasty in the treatment of symptomatic sacral Tarlov cysts (TCs). METHODS: A retrospective analysis was performed on the clinical data and follow-up data of 71 patients with symptomatic sacral TCs who underwent reinforced radiculoplasty in the Neurosurgery Department of Peking University Third Hospital from June 2018 to March 2021. All the operations were performed under neuroelectrophysiological monitoring. Intraoperative cyst exploration, partial resection of the cyst wall, narrowing of the leak, nerve root sleeve radiculoplasty and artificial dural reinforcement were performed. The incidence of postoperative complications and new neurological dysfunction was analyzed. Visual analogue scale (VAS) was used to assess the changes of pain before and after surgery. The Japanese Orthopedics Association (JOA) low back pain score was used to evaluate the changes in nerve function before and after surgery. RESULTS: In the study, 71 patients had 101 TCs, 19 (18.8%) TCs originated from the left S1 nerve, 26 (25.7%) originated from the left S2 nerve, 3 (3.0%) originated from the left S3 nerve, 14 (13.9%) originated from the right S1 nerve, 33 (32.7%) originated from the right S2 nerve, 6 (5.9%) originated from the right S3 nerve, all the TCs underwent reinforced radiculoplasty. Deep infection (1 case), subcutaneous effusion (1 case), fat li-quefaction (1 case) and urinary tract infection (4 cases) were recorded postoperatively. The patients were followed up for 12-43 months (median, 26 months). Two cases had new urinary retention after operation, and the catheter was removed at the end of the first and second months respectively. One case had new fecal weakness, which improved after 3 months. Compared with preoperation, VAS decreased significantly at the last follow-up [median, 6 (4-9) vs. 1 (0-5), Z=-7.272, P < 0.001], JOA score increased significantly [median, 20 (16-25) vs. 27 (18-29), Z=-7.265, P < 0.001]. There were 18 cured cases (25.4%), 41 excellent cases (57.7%), 8 effective cases (11.3%), and 4 invalid cases (5.6%). The total efficiency was 94.4% (67/71). Two (1.98%) cysts recurred. CONCLUSION: For patients with symptomatic sacral TCs, reinforced radiculoplasty can significantly improve the pain and nerve function, which is safe and reliable.

[Analysis of HIV-1 genetic subtype and pretreatment drug resistance among men who have sex with men infected with HIV-1 from 19 cities of 6 provinces in China].

Objective: To investigate the distribution of HIV-1 genetic subtypes and pretreatment drug resistance (PDR) among men who have sex with men (MSM) from 19 cities of 6 provinces in China. Methods: From April to November 2019, 574 plasma samples of ART-naive HIV-1 infected MSM were collected from 19 cities in Hebei, Shandong, Jiangsu, Zhejiang, Fujian, and Guangdong provinces, total ribonucleic acid (RNA) was extracted and amplified the HIV-1 pol gene region by nested polymerase chain reaction (PCR) after reverse transcription. Then sequences were used to construct a phylogenetic tree to determine genetic subtypes and submitted to the Stanford drug resistance database for drug resistance analysis. Results: A total of 479 samples were successfully amplified by PCR. The HIV-1 genetic subtypes included CRF01_AE, CRF07_BC, B, CRF55_01B, CRF59_01B, CRF65_cpx, CRF103_01B, CRF67_01B, CRF68_01B and unrecognized subtype, which accounted for 43.4%, 36.3%, 6.3%, 5.9%, 0.8%, 0.8%, 0.4%, 0.4%, 0.2% and 5.5%, respectively. The distribution of genetic subtypes among provinces is statistically different (χ2=44.141, P<0.001). The overall PDR rate was 4.6% (22/479), the drug resistance rate of non-nucleoside reverse transcriptase inhibitors, nucleoside reverse transcriptase inhibitors, and protease inhibitors were 3.5% (17/479), 0.8% (4/479) and 0.2% (1/479), respectively. The PDR rate of recent infections was significantly higher than that of long-term infections (χ2=4.634, P=0.031). Conclusions: The HIV-1 genetic subtypes among MSM infected with HIV-1 from 19 cities of 6 provinces in China are diverse, and the distribution of subtypes is different among provinces. The overall PDR rate is low, while the PDR rate of recent infections was significantly higher than that of long-term infections, suggesting the surveillance of PDR in recent infections should be strengthened.

[Effect of porous zirconia ceramics on proliferation and differentiation of osteoblasts].

OBJECTIVE: To investigate the effect of porous surface morphology of zirconia on the proliferation and differentiation of osteoblasts. METHODS: According to different manufacturing and pore-forming methods, the zirconia specimens were divided into 4 groups, including milled sintering group (M-Ctrl), milled porous group (M-Porous), 3D printed sintering group (3D-Ctrl) and 3D printed porous group (3D-Porous). The surface micromorphology, surface roughness, contact angle and surface elements of specimens in each group were detected by scanning electron microscope (SEM), 3D laser microscope, contact angle measuring device and energy-dispersion X-ray analysis, respectively. MC3T3-E1 cells were cultured on 4 groups of zirconia discs. The cell morphology of MC3T3-E1 cells on zirconia discs was eva-luated on 1 and 7 days by SEM. The cell proliferation was detected on 1, 3 and 5 days by cell counting kit-8 (CCK-8). After osteogenic induction for 14 days, the relative mRNA expression of alkaline phosphatase (ALP), type Ⅰ collagen (Colla1), Runt-related transcription factor-2 (Runx2) and osteocalcin (OCN) in MC3T3-E1 cells were detected by real-time quantitative polymerase chain reaction. RESULTS: The pore size [(419.72±6.99) µm] and pore depth [(560.38±8.55) µm] of 3D-Porous group were significantly larger than the pore size [(300.55±155.65) µm] and pore depth [(69.97±31.38) µm] of M-Porous group (P < 0.05). The surface of 3D-Porous group appeared with more regular round pores than that of M-Porous group. The contact angles of all the groups were less than 90°. The contact angles of 3D-Ctrl (73.83°±5.34°) and M-Porous group (72.7°±2.72°) were the largest, with no significant difference between them (P>0.05). Cells adhered inside the pores in M-Porous and 3D-Porous groups, and the proliferation activities of them were significantly higher than those of M-Ctrl and 3D-Ctrl groups after 3 and 5 days' culture (P < 0.05). After 14 days' incubation, ALP, Colla1, Runx2 and OCN mRNA expression in 3D-Porous groups were significantly lower than those of M-Ctrl and 3D-Ctrl groups (P < 0.05). Colla1, Runx2 and OCN mRNA expressions in M-Porous group were higher than those of 3D-Porous group (P < 0.05). CONCLUSION: The porous surface morphology of zirconia can promote the proliferation and adhesion but inhibit the differentiation of MC3T3-E1 cells.

[Willingness of post-exposure prophylaxis and possible related factors in men who have sex with men].

Objective: To analyze the willingness of post-exposure prophylaxis (PEP) to prevent HIV transmission and related factors in men who have sex with men (MSM). Methods: Cross sectional survey design was used in this study. After informed consent, MSM aged 18 years or above and having had homosexual anal or oral sex in the past 6 months were recruited through "i WeChat" official account between September and November, 2019. Results: Of 1 517 MSM were surveyed, the proportion of MSM who had ever heard of PEP were 72.5% (1 100/1 517) and 87.9%(1 333/1 517) of the MSM said they would like to use PEP if it is needed.Multivariate logistic regression analysis suggested that aged above 25 year (OR=1.807, 95%CI: 1.090-2.995), HIV test history (OR=1.953, 95%CI: 1.171-3.256) and being aware of PEP (OR=2.163, 95%CI: 1.468-3.186) were the positive factors for PEP use, but an aware of the HIV status of sexual partner was the negative factor for PEP (OR=0.602, 95%CI: 0.407-0.890). Among MSM who had ever heard of PEP, the positive factors for PEP use included living in Zhejiang (OR=1.942, 95%CI: 1.097-3.438), aged above 25 years (OR=2.431, 95%CI: 1.331-4.439), being aware of PEP (OR=3.714, 95%CI: 1.532-9.007) obtaining information about PEP service from MSM organization/volunteer/health organization. Conclusions: MSM's willingness to use PEP services was relatively high. Age, awareness of PEP related knowledge, and awareness of sexual partner's HIV infection status were the related factors. MSM organization/volunteer/health organization were the main forces for PEP promotion in MSM.

Forensic Analysis of 43 Medical Disputes Caused by Death after Cardiac Surgery.

ABSTRACT: Objective To explore the causes and characteristics of medical disputes caused by death after cardiac surgery and to analyze the pathological changes after cardiac surgery and the key points of forensic anatomy, thus to provide pathological evidence for clinical diagnosis and treatment of cardiac surgery and judicial appraisal as well as reference for the prevention of medical disputes in such cases. Methods Forensic pathological cases of medical disputes caused by death after cardiac surgery which were accepted by the Center for Medicolegal Expertise of Sun Yat-Sen University from 2013 to 2018 were analyzed retrospectively from aspects such as causes of death, pathological diagnosis, surgery condition, medical misconduct, and so on. Results The causes of death after cardiac surgery of 43 patients were abnormal operation, low cardiac output syndrome, postoperative infection, postoperative thrombosis, and other diseases. Among the 43 cases, there were 18 cases without medical fault while 25 cases had medical fault. Conclusion The medical disputes caused by death after cardiac surgery are closely related to the operative technique and postoperative complications. The causes of medical faults include defects in diagnosis and treatment technique, as well as unfulfillment of duty of care.

[Situation of anal sex among low-tier female sex workers in the Demonstration Areas of Comprehensive AIDS Responses in Zhejiang province].

Objective: To analyze the prevalence of anal sex and related factors in low-tier female sex workers (FSWs) in the demonstration areas of comprehensive AIDS responses (DACAR) in Zhejiang province. Method: In 2013, a survey on low-tier FSWs was carried out in 21 Demonstration Areas of AIDS Responses in Zhejiang. Experience of having anal sex with clients in the last month was taken as dependent variable while independent variables would include perception and characteristics related to behavior of the FSWs. The multivariate logistic regression analyses were conducted to identify the factors related to anal sex in low-tier FSWs. Results: A total of 2 645 low-tier FSWs were interviewed. Among these FSWs, 67.9% (1 796/2 645) were over 26 years old, 89.9% (2 378/2 645) were with education level of junior high school or below, 58.4% (1 546/2 645) were married, 78.2% (2 068/2 645) were from other provinces, 68.6% (1 814/2 645) had income level less than 4 000 Yuan, and rates of anal sex with client in the last month were 5.03% (133/2 645). Results from the multivariate logistic regression analysis of related factors of anal sex with client in the last month showed that among the low-tier FSWs, the venues of having commercial sex were in hair salons/massage parlors (OR=7.31, 95%CI: 2.27-23.59), roadside shops (OR=7.89, 95%CI: 2.27- 27.40) or other places (OR=4.65, 95%CI: 1.23-17.53), when compared with the street-women service. FSWs often engaged in commercial sex business in three or more counties (OR=1.68, 95%CI: 1.01-2.81), when compared with FSWs often engaged in commercial sex business just one county. FSWs had sex with only middle-aged and the elderly clients (OR=0.45, 95%CI: 0.30-0.66), when compared with FSWs had sex with young or middle-aged and the elderly clients. FSWs had risk perception for sexually transmitted disease (STD) (OR=2.00, 95%CI: 1.20-3.32), when compared with FSWs with no risk perception. FSWs had oral sex experience with their clients in the last month (OR=7.29, 95%CI: 4.78-11.12), when compared with the ones without oral sex. The above said factors were all related to the incidence of anal sex. Conclusions: Certain numbers of low-tier FSWs had anal sex experiences with their clients, especially those who had oral sex were more likely to have anal sex in DACAR in Zhejiang province. Attention should be paid to anal sex behavior when conducting behavior-related intervention programs, targeting on the low-tier FSWs.

[Status and associatied factors of anal sexual intention in casual sex behavior among heterosexual college students in Zhejiang Province].

Objective: To identify the status and risky factors of anal sexual intention in casual sex behavior in Zhejiang province. Methods: Stratified cluster sampling was conducted among college students in 13 colleges in 11 cities between October to November, 2018. 482 students were enrolled who self-reported "heterosexuality "and" ever had casual sex behavior". A self-designed network questionnaire was complimented containing basic information, knowledge of HIV, sexual behavior. Chi-square test was used to compared the difference of anal sex intention between different characteristic. The multivariate logistic regression methods was used to analyze the influence factors. Results: Among 482 students, the age was (20±1.442) years old. And 87.3% (421) were male and 29.0% (140) were from other province. The rate of anal sex intention were 19.4% (94/482) in total, with the rates of 38.1% (24/63) and 14.4% (53/367) in students with sexual number more than 5 and less than 5 (P<0.001), separately. Compared with students searching casual sexual partner with non-internet access (17.0%, 16/201), students searching sexual partner with internet access had higher risk of anal sex practice (27.8%, 78/281) (P<0.001). The rate of anal sex practice among students reporting "ever had casual sex after drinking "and" never had casual sex after drinking" were 30.5% (64/210) and 9.4% (25/266) (P<0.001). The multivariate logistic regression results revealed that compared with students searching casual sexual partner with non-internet access and reporting "never had casual sex after drinking", subjects searching sexual partner with internet access(OR (95%CI)=2.65 (1.34-5.23)) and "ever had casual sex after drinking" OR (95%CI)=3.02 (1.65-5.33) were more likely had higher risk of anal sex practice. Conclusion: Heterosexual college students in Zhejiang Province tend to have anal intercourse with causal sexual partners. Searching for causal sexual partners on internet or mobile phone dating software and having temporary sexual behavior after drinking were correlated factors.

[Analysis of oral sexual behavior and related factors among male students from college graduation in Hangzhou].

Objective: To study oral sexual behavior and related factors among male students. Methods: The male students from college graduation in Hangzhou were selected as the study objects, and the inclusion criteria were having had sex and informed the type of behavior. A total of 490 subjects were finally included. Results: Among 490 male students, the 20-22 years old, 23 years old and 24-27 years old age groups accounted for 38.8% (n=190), 37.8% (n=185) and 23.3% (n=114), respectively. A total of 99 (20.2%) cases had oral sexual behavior, of which only 14 (2.9%) cases used condom. After adjusting for unplanned pregnancy, stage of sexual behavior, sexually transmitted diseases infection possibility, sexual orientation factors, normal/unnormal family relationship, more than 2 sexual partners, casual sexual partners, sexual partners from other college, sexual partners from society, sexual behavior in past 1 year were positively associated with oral sexual behavior. The corresponding OR (95%CI) values were 2.77 (1.40-5.50), 2.29 (1.27-4.15), 2.68 (1.23-5.88), 2.45 (1.34-4.48), 2.47 (1.15-5.33) and 2.04 (1.05-3.96), respectively. Use of condoms was negatively associated with oral sexual behavior, the OR (95%CI) value was 0.20 (0.09-0.42). Conclusion: Normal/unnormal family relationship, more than two sexual partners, casual sexual partners, sexual partners from other college, sexual partners from society, sexual behavior in last one year and condom use in each vaginal sexual behavior were associated with oral sexual behavior.

[Evaluation on the confidence of refusing unprotected sex behavior and related factors among college students in Zhejiang province].

Objective: To understand the confidence-related factors of refusing unprotected sex behavior among college students in Zhejiang province. Methods: Stratified cluster random sampling method was conducted among college students from 13 colleges and universities in Zhejiang province, from October to November, 2018. A total of 3 718 students who self-reported "ever having had sexual contacts" were enrolled. Chi-square test was used to compare the confidence of rejecting unprotected sex under different demographic characteristics, sexual attitude/behaviors and different intervention approaches. Multivariate logistic regression model was used to analyze the related factors. Results: A total of 3 718 college students were involved in this study with average age as (20.17±1.38) years old and 70.5% (2 620/3 718) were male. The proportions of having confidence to refuse unprotected sex behavior were 74.9% (1 963/2 620) of male and 77.9% (896/1 098) of female students, respectively. According to the results from multivariate logistic regression analysis, factors that related to the confidence of refusing unprotected sex behavior in male students would include, did not accept casual sex behavior (compared with accepted students, OR=2.247, 95%CI: 1.828-2.762), did not accept homosexual behavior (compared with accepted students, OR=1.810, 95%CI: 1.302- 2.516), having casual sex behavior in the past one year (compared with having no sex behavior, OR=1.345, 95%CI: 1.051-1.721), aware of the availability of HIV self-test reagents service in college (compared with did not knew, OR=1.381, 95%CI: 1.011-1.887), having taken the HIV infection risk self-assessment in college (compared with did not take, OR=1.707, 95%CI: 1.374-2.121). In female students, the factors would include: being urban resident (compared with rural residence, OR=1.816, 95%CI: 1.225-2.693), 21 years old or above (compared with 20 years old or below, OR=1.469, 95%CI: 1.075-2.007), having taken the HIV infection risk self-assessment in college (compared with did not take, OR=1.597, 95%CI: 1.093-2.333), etc. Conclusions: Both male and female college students had higher confidence in refusing unprotected sex behavior. For male students, refusing casual or homosexual contacts, having casual sex in the recent year, knowing HIV self-test reagents service and having had HIV-related risk self-assessment in college as related factors. However, for female students; city residence, 21 years old and above, and having a HIV infection risk self- assessment in college appeared as related factors. Sexual health education should be strengthened to reduce unprotective sex behavior and to promote HIV infection risk self-assessment among the college students.

[Previous HIV testing behavior and related factors in men who have sex with men in gay bathroom in Hangzhou, Zhejiang province].

Objective: To understand the related factors on previous HIV testing behavior among MSM who visit gay bathroom in Hangzhou, Zhejiang province. Methods: Through time-location sampling (TLS) survey, men who had oral sex or anal sex with men in past 6 months were interviewed in the gay bathroom in Hangzhou from October 2015 to January 2016. Software SPSS 22.0 was used to analyze the HIV testing acceptance, sexual behaviors and condom usage of MSM during past 6 months, and χ(2) test and logistic regression model were used for univariate and multivariate analyses. Results: Our study planned to recruit 480 gay bathroom MSM, due to the unwilling or other factors, 465 MSM were surveyed. A total of 47.3% (220/465) gay bathroom MSM received HIV testing during past 6 months. Multivariate analysis indicated that being married (OR=0.35, 95%CI: 0.18-0.69), peer education (OR=4.31, 95%CI: 1.32-14.09), homosexual behavior during past 6 months (OR=1.85, 95%CI: 1.08-3.14), extramarital heterosexual behavior during past 6 months (OR=4.12, 95%CI: 2.45-6.91) might be positive factors related with HIV testing acceptation in MSM. Conclusion: Being married, homosexual behavior during past 6 months, extramarital heterosexual behavior, partner education might be the positive factors related with acceptance of HIV testing among gay bathroom MSM. Therefore, peer education needs to be strengthened. HIV testing after high risk sexual behavior needs to be promoted in MSM.

Study on the levels of uric acid and high-sensitivity C-reactive protein in ACS patients and their relationships with the extent of the coronary artery lesion.

OBJECTIVE: We evaluated uric acid (UA) and high-sensitivity C-reactive protein (hs-CRP) levels in different clinical types of acute coronary syndromes (ACS) and in relationship with the severity of coronary artery lesions. Furthermore, we explored its clinical significance. PATIENTS AND METHODS: From June 2013 to January 2015, we studied patients in their first onset of symptoms and hospitalization for coronary angiography. According to coronary angiography results, we divided patients into two groups: 93 patients with ACS and 30 patients with normal coronary arteries as the control group. ACS patients were divided further into three subgroups: patients with ST-segment elevation myocardial infarction (STEMI) (n=34); patients with non-ST segment elevation myocardial infarction (NSTEMI) (n=29); and patients with unstable angina (n=30). According to their Gensini scores, patients were divided into mild, moderate and severe groups. We compared UA and hs-CRP levels and the relationship with Gensini scores between different groups. RESULTS: UA and hs-CRP levels in the ACS group were higher than those in the control group (p < 0.05). UA and hs-CRP levels in the STEMI group were higher than those in the NSTEMI, unstable angina and control groups (p < 0.05). UA and hs-CRP levels in the NSTEMI patients were higher than those in the unstable angina and control groups (p < 0.05). UA and hs-CRP levels in the unstable angina patients were higher than those in the control group (p < 0.05). hs-CRP levels in the STEMI patients were higher than the other groups (p < 0.05). hs-CRP levels in the NSTEMI patients were higher than the unstable angina and the control groups (p < 0.05) while hs-CRP levels in the unstable angina patients were higher than the control group (p < 0.05). Additionally, according to the Gensini score group, we discovered that ACS patients in the severe group had higher hs-CRP levels than the other three groups (p < 0.05) while the moderate group had higher levels than the other two groups (p < 0.05). The mild group had higher levels than the control group (p < 0.05). Correlation analysis suggested that UA levels and Gensini scores had a positive correlation (p < 0.05). hs-CRP levels and Gensini scores also showed a positive correlation (p < 0.05). CONCLUSIONS: UA and hs-CRP levels should be considered as factors to use in the risk stratification in ACS patients.

[Willingness for HIV test and associated factors among 535 college students who had sex in Zhejiang province].

Objective: To understand the willingness of HIV test uptake and associated factors among sexual active college students. Methods: A cross-sectional study were conducted among college students from 11 cities in Zhejiang province, and those who had sexual behaviors were included in this study. Results: A total of 9 615 students completed the questionnaire, and 6.5% (619/9 468) of them had sexual behaviors. A total of 535 students were recruited in this study. And 77.2% of them were willing to receive HIV test. Hospitals and CDC were commonly accepted testing sites. Being sophomore and junior (aOR=2.618, 95%CI: 1.511-4.536), being aware of rapid growing HIV epidemic among students who are men who have sex with men (MSM) (aOR=1.879, 95%CI: 1.153-3.060) and being aware of HIV infection risk (aOR=1.701, 95% CI: 1.041-2.780) were associated with HIV test willingness. Conclusions: Future effort should be made to increase the awareness of HIV infection, including the severity of AIDS epidemic in college students and infection source, in order to increase their willingness to receive HIV test. School-based HIV counsel and test sites should be set up to provide convenient and private HIV test service.

Genetic diversity and structure of the threatened species Sinopodophyllum hexandrum (Royle) Ying.

Sinopodophyllum hexandrum is an important medicinal plant that has been listed as an endangered species, making the conservation of its genetic diversity a priority. Therefore, the genetic diversity and population structure of S. hexandrum was investigated through inter-simple sequence repeat analysis of eight natural populations. Eleven selected primers generated 141 discernible fragments. The percentage of polymorphic bands was 37.59% at the species level, and 7.66-24.32% at the population level. Genetic diversity of S. hexandrum was low within populations (average HE = 0.0366), but higher at the species level (HE = 0.0963). Clear structure and high genetic differentiation were detected between populations using unweighted pair groups mean arithmetic and principle coordinate analysis. Clustering approaches clustered the eight sampled populations into three major groups, and AMOVA confirmed there to be significant variation between populations (63.27%). Genetic differentiation may have arisen through limited gene flow (Nm = 0.3317) in this species. Isolation by distance among populations was determined by comparing genetic distance versus geographical distance using the Mantel test. The results revealed no correlation between spatial pattern and geographic location. Given the low within-population genetic diversity, high differentiation among populations, and the increasing anthropogenic pressure on this species, in situ conservation measures, in addition to sampling and ex situ preservation, are recommended to preserve S. hexandrum populations and to retain their genetic diversity.

Isolation and expression studies of the ERD15 gene involved in drought-stressed responses.

The early response to the dehydration 15 (ERD15) gene is widely involved in the processes of signal transduction, programmed cell death, gene transcription, and stress tolerance in plants. In a previous study, the ERD15 gene was shown to be an important regulator of the abscisic acid response and salicylic acid-dependent defense pathway, acting as an important negative regulator of abscisic acid. The complete IbERD15 gene (accession No. KF723428) was isolated by reverse transcription-polymerase chain reaction. The IbERD15 gene contains an open reading frame of 504 bp, encodes a peptide of 167 amino acids, and has a molecular mass of 18.725 kDa. The transcript levels of the IbERD15 gene in a variety of tissues were examined by digital gene expression profiling. The roots of the sweet potato were treated by 3 degrees of polyethylene glycol, and the results indicate that the IbERD15 gene might play an important role in the defense response to drought stress. Moreover, the IbERD15 gene was successfully transformed into yeast cells for analysis of drought tolerance in transgenic yeast.

Cell specificity and molecular mechanism of antibacterial and antitumor activities of carboxyl-terminal RWL-tagged antimicrobial peptides.

Antimicrobial peptides (AMPs) constitute a diverse class of naturally occurring or synthetic antimicrobial molecules that have potential for use in the treatment of drug-resistant infections. Several undesirable properties of AMPs, however, may ultimately hinder their development as antimicrobial agents. Thus, new synthetic strategies, including primarily the de novo design of AMPs, urgently need to be developed. In this study, a series of peptides, H-(RWL) n (n = 1, 2, 3, 4, or 5), were designed. H represents GLRPKYS from the C-terminal sequence of AvBD-4. Our results showed that these RWL-tagged peptides can kill not only bacteria but also human hepatocellular carcinoma HepG2 cells. However, the peptide tagged with two repeats of RWL (GW13) showed less affinity to human embryonic lung fibroblast MRC-5 cells or human red blood cells (hRBCs) than HepG2 cells. These results demonstrated that GW13, with high amphiphilicity, exerted great selectivity toward bacteria and cancer cells, sparing host mammalian cells. The mechanism of action against bacteria was elucidated through combined studies of scanning electron microscopy (SEM) and fluorescence assays, showing that the peptide possessed membrane-lytic activities against microbial cells. The fluorescence assays illustrated that GW13 induced apoptosis in HepG2 cells. The cell morphology of HepG2 cells, observed by SEM, further illustrated that GW13 causes cell death by damaging the cell membrane. Our results indicate that GW13 has considerable potential for future development as an antimicrobial and antitumor agent.

Rational design of cationic antimicrobial peptides by the tandem of leucine-rich repeat.

Antimicrobial peptides represent ancient host defense effector molecules present in organisms across the evolutionary spectrum. Lots of antimicrobial peptides were synthesized based on well-known structural motif widely existed in a variety of lives. Leucine-rich repeats (LRRs) are sequence motifs present in over 60,000 proteins identified from viruses, bacteria, and eukaryotes. To elucidate if LRR motif possesses antimicrobial potency, two peptides containing one or two LRRs were designed. The biological activity and membrane-peptide interactions of the peptides were analyzed. The results showed that the tandem of two LRRs exhibited similar antibacterial activity and significantly weaker hemolytic activity against hRBCs than the well-known membrane active peptide melittin. The peptide with one LRR was defective at antimicrobial and hemolytic activity. The peptide containing two LRRs formed α-helical structure, respectively, in the presence of membrane-mimicking environment. LRR-2 retained strong resistance to cations, heat, and some proteolytic enzymes. The blue shifts of the peptides in two lipid systems correlated positively with their biological activities. Other membrane-peptide experiments further provide the evidence that the peptide with two LRRs kills bacteria via membrane-involving mechanism. The present study increases our new understanding of well-known LRR motif in antimicrobial potency and presents a potential strategy to develop novel antibacterial agents.

Effect of supplemental Bacillus cultures on rumen fermentation and milk yield in Chinese Holstein cows.

Two experiments were conducted to study the effect of supplemental 100 g/day of live Bacillus cultures (2 x 10(11) cell of Bacillus subtilis and Bacillus licheniformis) on rumen fermentation as well as milk yield and composition in Chinese Holstein cows. In experiment 1, investigating 3 x 10 cows, milk yield and milk protein were increased by using B. licheniformis (p < 0.05) in comparison with an unsupplemented group and the B. subtilis group. Body weight was not significantly affected by Bacillus culture supplementation (p > 0.05). Percentage of milk fat and lactose was not significantly different between treatments (p > 0.05). But milk protein increased with B. licheniformis supplementation (p < 0.05). In experiment 2, carried out with three non-lactating ruminally and duodenally fistulated cows, results showed that B. licheniformis supplementation increased microbial crude protein flow into duodenum (p < 0.05) and decreased the ammonia nitrogen concentration in ruminal fluid at 0.5 h, 1 h, 3 h, 6 h after morning feeding (p < 0.05). Bacillus licheniformis supplementation increased total VFA and acetate concentration in ruminal fluid at 0.5 h, 1 h, 3 h, 6 h after morning feeding (p < 0.05). Bacillus subtilis had no significant effect on rumen fermentation characteristics, duodenal microbial N flow and ruminal apparent nutrient digestibility (p > 0.05). Bacillus licheniformis increased ruminal apparent nutrient digestibility of neutral detergent fibre, acid detergent fibre, and organic matter (p < 0.05).

Surface modification using photocrosslinkable chitosan for improving hemocompatibility.

Immobilization of the anticoagulative or antithrombogenic biomolecule has been considered as one of the important methods to improve the blood compatibility of artificial biomaterials. In this study, a novel immobilization reaction scheme was utilized to incorporate O-butyrylchitosan (OBCS) onto the activated glass surface with an aim to develop an anticoagulative substrate. Activation of the glass surface was carried out by silanization and then OBCS was grafted to the silanized surface via a radiation grafting technique. The OBCS-grafted glass surfaces were characterized by electron spectroscopy for chemical analysis (ESCA) and atomic force microscopy (AFM). The blood compatibility of the OBCS-grafted glass was evaluated by platelet rich plasma (PRP) contacting experiments and protein adsorption experiments in vitro. These results have demonstrated that the surface with immobilized OBCS shows much less platelet adhesive and fibrinogen adsorption compared to the control surface. Therefore, the novel reaction scheme proposed here is very promising for future development of an anticoagulative glass substrate.

[Surveillance of imported falciparum malaria in Yongkang County, Zhejiang Province].

From August 1985 to February 1987, 43 cases with falciparum malaria were noted in Yongkang County of Zheijiang Province, an area breed from the disease. These patients had been to the border area between Yunnan Province and Burma, approximately making up 5-7% of the returned population from the endemic area. Most of cases were found during the periods of January to March and June to August when they came home. No introduced case was reported due to prompt case diagnosis and treatment as well as immediate focal management.