[Transmission characteristics and risk factors of household COVID-19 clusters caused by 2019-nCoV Omicron variant in Tianjin]

Objective: To understand the transmission characteristics and risk factors of household COVID-19 clusters caused by 2019-nCoV Omicron variant in Tianjin and provide evidence for COVID-19 prevention and control. Methods: Field epidemiological method was used to investigate the epidemiological characteristics of COVID-19 cases, and descriptive analysis was used to describe the epidemiological information. Results: A total of 430 cases were reported in this epidemic in Tianjin, in which 409 cases were included in this study. Among these cases, 70.90% (290/409) occurred in families. The family secondary attack rate was 33.64% The family secondary attack rate in age group 12-17 years (13.79%) was significantly lower than that in age group 18-49 years (36.48%), the OR was 0.378 (95%CI: 0.170-0.840). The logistic regression analysis showed that compared with centralized quarantine, the OR of the index cases found in closed-off/controlled areas and in home quarantine were 2.951 (95%CI:1.322-6.586) and 2.287 (95%CI:1.164-4.495), respectively, compared with the cases without sore throat, the OR of the index cases with sore throat was 3.003 (95%CI: 1.576-5.720), and compared with cases in families without completed COVID-19 vaccinations in all members, the OR of the cases in families with completed COVID-19 vaccinations in all members was 0.268 (95%CI: 0.132-0.552). Conclusions: The risk of household transmission of infection with Omicron variant was high. Detecting the index case in closed-off/controlled areas or in home quarantine and sore throat in index cases were the risk factors of the household transmission, completed COVID-19 vaccination was the protective factor.

[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.

[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.

[The characteristics of recent HIV-1 infection and associated factors in Tianjin]

The newly reported HIV infected cases was collected, and HIV blood samples were detected to identify recent HIV infection in Tianjin during 2008-2015. Factors associated with HIV-1 infection were analyzed by the univariate and multivariate unconditional logistic regression. The recent HIV-1 infection proportion of homosexuals increased from 37.70% in 2008 to 83.68% in 2015. Those cases who aged ≤30 years (OR=1.53, 95%CI: 1.30-1.79), in han ethnic group (OR=1.40, 95%CI: 1.02-1.91), students (OR=1.79, 95%CI: 1.28-2.51) were more likely to be recent infected. The cases who had a high school education (OR=1.28, 95%CI: 1.05-1.56) or collage education (OR=1.23, 95%CI: 1.00-1.50) were more likely to be recent infected than those who had a primary school education. Compared with patients identified by hospitals, the recent HIV infections were more likely to be found through voluntary counseling and testing (VCT), STD outpatients, men who have sex with men (MSM) investigation and unpaid blood donors. Homosexual transmission has become the major route of HIV-1 recent infection in Tianjin.

[Research on feasibility and effectiveness of the bone-implant contact evaluation in dogs by micro-CT]

Objective: To discuss the feasibility and effectiveness of using micro-CT in bone-implant contact (BIC) evaluation in dogs, and to provide reference for clinical and scientific research. Methods: Bilateral mandibular second premolar and first molar of six male Beagle dogs were extracted. After 3 months' healing, eight implants were placed in bilateral mandible of each dog, four on each side. Dogs were sacrificed at 2 weeks, 4 weeks and 8 weeks after implant placement, two on each time point. Samples were scanned with micro-CT and digitally reconstructed. Bone-implant interface was analyzed at different analysis regions (25, 50 and 100 μm from implants' surface), different detection range models were obtained (each time point consists 48 models), and BIC was evaluated, and the results were counted as micro-CT(25), micro-CT(50), and micro-CT(100) groups. Then undecalcified slides were made (three slides for each sample) and stained with toluidine blue for observation and analysis of BIC using an optical microscope, and the results were counted as optical microscope groups. The advantages and disadvantages, evaluation efficiency and BIC of different methods were analyzed. Results: To evaluate BIC of single sample, it took about 90 minutes by micro-CT, which was much lower than the time of 14 days by optical microscope. The success rates of modeling of micro-CT(25), micro-CT(50), and micro-CT(100) groups all were 100.0% (48/48), and total success rate of micro-CT group was 100.0% (144/144). For optical microscope groups, the success rates of making slides 2, 4, 8 weeks were 89.6% (43/48), 93.8% (45/48) and 93.8% (45/48), respectively, and total success rates of optical microscope group was 92.4% (133/144). At 2, 4,8 weeks after implantation, BIC in micro-CT(25) group was significantly smaller than that in optical microscope group at the same time point (P<0.05). However, at 2, 4,8 weeks after implantation, BIC of the micro-CT(50) and micro-CT(100) groups showed no significant difference with optical microscope groups at the same time point (P>0.05). A significant correlation (P<0.001, each) was seen between slides and micro-CT (25, 50, 100 μm groups) concerning BIC (r=0.680, r=0.892, r=0.713), and error bias was -19.4%, -0.9%, 3.0%, respectively. The probability within the 95% limits of agreement were 97.9%. Conclusions: Micro-CT is a faster, simpler and more efficient way to analyze BIC at the implant-bone interface than optical microscope observation. BIC analysis by selecting 50 μm from implants' surface as analysis region using micro-CT is in consistent with that using the optical microscope.

[Sentinel surveillance for viral hepatitis C in China, 2016-2017]

Objective: To understand the prevalence of hepatitis C virus (HCV) infection in 5 populations in China during 2016-2017 and provide evidence for the estimation of prevalence trend of hepatitis C and evaluation on the prevention and control effect. Methods: A total of 87 national sentinel surveillance sites for hepatitis C were set up in 31 provinces (autonomous regions and municipalities) of China to obtain the information about HCV infection prevalence in 5 populations, including volunteer blood donors, people receiving physical examination, patients receiving invasive diagnosis and treatment, patients receiving hemodialysis, and clients visiting family planning outpatient clinics. From April to June, 2016 and 2017, cross-sectional surveys were repeatedly conducted in the 5 populations and blood samples were collected from them for HCV antibody detection. Results: In 2016, 86 sentinel sites completed the surveillance (one sentinel site was not investigated), and 115 841 persons were surveyed. The overall HCV positive rate was 0.38% (442/115 841, 95%CI: 0.23%-0.53%). In 2017, all the 87 sentinel sites completed the surveillance, and 120 486 persons were surveyed. The overall HCV positive rate was 0.37% (449/120 486, 95%CI: 0.23%-0.52%). In 2016 and 2017, the anti-HCV positive rates were 4.46% (223/5 005, 95%CI: 2.18%-6.73%) and 4.39% (216/4 919, 95%CI: 2.29%-6.50%) respectively in hemodialysis patients, 0.85% (44/5 200, 95%CI: 0.27%-1.42%) and 0.70% (36/5 150, 95%CI: 0.15%-1.24%) respectively in patients receiving invasive diagnosis and treatment and remained to be ≤0.25% in volunteer blood donors, people receiving physical examination and clients visiting family planning outpatient clinics. Results for the comparison of the anti-HCV positive rates in the 5 populations indicated that the differences were significant (F=23.091, P<0.001 in 2016 and F=20.181, P<0.001 in 2017). Conclusions: Data from the sentinel surveillance of HCV infection on prevalence in China showed that the anti-HCV positive rates varied in the 5 populations during 2016-2017. The anti-HCV positive rate appeared the highest in the hemodialysis patients, followed by that in the patients receiving invasive diagnosis and treatment, and the prevalence of HCV infection in other 3 populations were at low levels.

14,15-Secopregnane-type C21-steriosides from the roots of Cynanchum stauntonii

Nine 14,15-secopregnane-type C₂₁-steriosides, stauntosides U, V, V₁-V₃, W and C₁-C₃, as well as two known C₂₁-steriosides, were isolated from the roots of Cynanchum stauntonii. Stauntosides U, V and V₁-V₃ share the same basic structural features of 8α:14α,14:16,15:20,18:20-tetraepoxy-14,15-secopregn-6-ene-3β,5α,9α-triol, with the numbering system following that of C₂₁-pregnanes. The aglycones of stauntosides U, V and V₁-V₃ are classified into two subcategories, the 5,9-dihydroxy groups and 5α:9α-peroxy bridge, according to the oxidative states of the two hydroxy groups at the C-5 and C-9 positions. The anti-inflammatory activity of the major compounds was assessed in an in vitro inflammatory model of mouse peritoneal macrophages using IC₅₀ values of the inhibition of nitric oxide (NO) production as an indicator. Stauntosides V₁ and V₃ exhibited target activity with IC₅₀ values of 9.3 μM and 12.4 μM, respectively, compared with dexamethasone, which was used as a positive control.

Anti-inflammatory effect of a resveratrol derivative 3,4,5-trimethoxy-4',5'-dihydroxy-trans-stilbene (WL-09-5) via ROS-mediated NF-κB pathway

Inflammation derived from macrophages activation leads to various diseases. Synthetic modifications of resveratrol have been shown to have better anti-inflammatory activities. In this study, croton oil-induced mouse ear edema and lipopolysaccharides (LPS)-stimulated RAW264.7 macrophages were used to evaluate the anti-inflammatory effects of WL-09-5, a derivative of resveratrol. Furthermore, the activation of NF-κB was determined. Results showed that WL-09-5 significantly reduced the croton oil-induced ear edema, scavenged NO and ROS production, and reduced the levels of TNF-α, IL-6, and IL-1β. Furthermore, WL-09-5 may significantly inhibit the translocation of NF-κB in macrophage cells stimulated by LPS in a dose-dependent manner, which is a potent mechanism of its anti-inflammatory effects. In conclusion, WL-09-5 is an underlying candidate for inflammatory diseases that need further investigations.

Anti-inflammatory Hydrolyzable Tannins from Myricaria bracteata

Twelve hydrolyzable tannins were obtained from the twigs of Myricaria bracteata, including two new hellinoyl-type dimers, bracteatinins D1 (1) and D2 (2); a new hellinoyl-type trimer, bracteatinin T1 (3); two known monomers, nilotinin M4 (4) and 1,3-di-O-galloyl-4,6-O-(aS)-hexahydroxydiphenoyl-β-d-glucose (5); six known dimers, tamarixinin A (6), nilotinin D8 (7), hirtellins A (10), B (9), and E (8), and isohirtellin C (11); and a known trimer, hirtellin T3 (12). The structures of the tannins were elucidated by spectroscopic data analysis and comparisons to known tannins. All compounds were evaluated as free radical scavengers using 1,1-diphenyl-2-picrylhydrazyl and hydroxy radicals and compared to the activity of BHT and Trolox. Compound 6 showed a significant anti-inflammatory effect on croton oil-induced ear edema in mice (200 mg/kg, inhibition rate 69.8%) and on collagen-induced arthritis in DBA/1 mice (20 mg/kg, inhibition rate 46.0% at day 57).

Genetic polymorphisms of the BMAP-28 and MASP-2 genes and their correlation with the somatic cell score in Chinese Holstein cattle

DNA sequencing, nested polymerase chain reaction (PCR), and PCR-restriction fragment length polymorphism were used to investigate mutations in the coding regions of the bovine myeloid antimicrobial peptide-28 (BMAP-28) and mannan-binding lectin-associated serine protease-2 (MASP-2) genes in 249 Chinese Holstein dairy cows. The associations between the polymorphisms and somatic cell score (SCS) were analyzed to determine the potential of these genes as genetic markers for breeding mastitis-resistant dairy cattle. The results revealed a C-86G synonymous mutation in the BMAP-28 gene that caused no alteration in the amino acid sequence. G553A mutation was found in the MASP-2 gene that led to the substitution of glycine with serine. The chi-square test showed that the G553A mutation was in Hardy-Weinberg equilibrium in the Chinese Holstein dairy cows, whereas the C-86G mutation was not. The variance analysis of the influence of group loci and different genotypes on the SCS showed that the SCS of genotype CC was significantly lower than those of genotypes CG and GG (P < 0.05) of the C-86G mutation, and that the SCS of genotype GG was significantly lower than those of genotypes GA and AA (P < 0.05) of the G553A mutation. Genotype combination analysis showed that the combination of the BMAP-28 genotype CC and the MASP-2 genotype GG was the best one, in which the SCS was significantly lower than those in the other combinations. Thus, this combination might be useful as a molecular and genetic marker of mastitis in Chinese Holstein dairy cows.

Effect of artificial musk aqueous extract on the expressions of inflammatory mediators released from lipopolysaccharide-stimulated RAW264.7 cells

OBJECTIVE

To identify the anti-inflammatory effects of artificial musk aqueous extract(AME)on lipopolysaccharide-stimulated cytokines secreted or released by RAW264.7 cells.

METHODS

Cytokines including interleukin(IL)-6,IL-10,and tumor necrosis factor Α were determined using cytokine enzyme-linked immunosorbent assay kits.

RESULT

Compared with model group,the levels of major cytokines such as tumor necrosis factor Α,IL-6,and IL-10 significantly decreased in different AME groups in a dose-dependent manner.

CONCLUSION

In lipopolysaccharide-stimulated RAW264.7 macrophages,AME can remarkably inhibit the release of inflammatory cytokines and thus exerts its anti-inflammatory effects.

Resolution and chiral recognition of muscone as well as actions on neural system

In this letter, (R)-muscone and (S)-muscone were prepared by optical resolution of dl-muscone using N,N'-dibenzyl-l-tartaramide or N,N'-dibenzyl-d-tartaramide, according to the method reported by Kunihiko Takabe. But we separated the diastereomers using EtOH instead of MeOH in the recrystallization step to get the goal product with higher optical purity and yield. The regulatory effect of muscone and its enantiomer on the neural system showed that they could prolong mouse hypoxia tolerance and dose-dependently enhance mouse spinal cord stimulation induced by strychnine nitrate. (R)-muscone and (S)-muscone had a synergistic action on shortening sleep time induced by sodium pentobarbital in mice.

Establishment of indirect enzyme-linked immunosorbent assay for artificial musk

Anti-inflammatory component (AIC) known as an important constituent of artificial musk exhibits bioactive effects on many pharmacological models. This study describes an immunochemical assay for the quality control of artificial musk in traditional Chinese medicine using an enzyme-linked immunosorbent assay. A polyclonal antibody against AIC was produced by rabbit. The method, at an effective measuring range of 3.13-200 ng/ml of AIC, 3 ng/ml limit of detection, and no cross-reaction with natural musk, successfully detected artificial musk in many traditional Chinese prescriptions containing artificial musk. The results demonstrated that a novel and reliable assay system for detection of artificial musk was generated.

[Effects of Vam3 on sodium nitroprusside-induced apoptosis and SIRT1 and p53 expression in rat articular chondrocytes]

This study is to investigate the effect of Vam3, a dimeric derivative of resveratrol, on SNP-induced apoptosis and its potential mechanism in rat articular chondrocytes. Isolated rat articular chondrocytes were treated with sodium nitroprusside (SNP), a NO donor, to induce apoptosis. Apoptosis percentage was evaluated by Annexin V-PI and nucleus fracture was examined by DAPI staining. Level of intracellular reactive oxygen species (ROS) was detected using 2, 7'-dichlorofluorescin diacetate (DCFH-DA) as a fluorescence probe by fluorescence microplate reader. The change in mitochondrial membrane potential was detected by TMRE staining. Expressions of SIRT1, acetylated p53 (ac-p53), cleaved caspase 9 and cleaved caspase 3 were determined by Western blotting. It showed that Vam3 up to 10 micromol x L(-1) could significantly reduce SNP-induced rat articular chondrocytes apoptosis (P < 0.01) and nucleus fracture, inhibit the increase of intracellular ROS level (P < 0.01) and reverse the decrease in mitochondrial membrane potential (P < 0.01). Simultaneously, Vam3 could upregulate the expression of SIRT1, deacetylate p53, and inhibit the cleavage of caspase 9 and caspase 3 (P < 0.01) of rat articular chondrocytes exposed to SNP. This study indicates Vam3 could protect rat articular chondrocytes against SNP-induced apoptosis, perhaps through the upregulation of SIRT1 and deacetylation of p53.

An Internet-based surveillance system for tuberculosis in Korea

SETTING

The Korea Tuberculosis Surveillance (KTBS) network includes 248 health centres throughout the country, as well as other public and private health institutions.

OBJECTIVE

To develop a web-based surveillance system for tuberculosis (TB) and to monitor implementation of the National TB Control Programme (NTP) on an ongoing basis.

DESIGN

A TB notification form was developed with new case definitions, and standardised to obtain uniform essential information of the cases with ease and speed. Data collection, compilation, analysis and feedback were made available at every level of the health authority via the Internet without restrictions of time and space.

RESULTS

The Internet-based surveillance system was successfully implemented across the country, providing real-time national figures of TB using different variables-patient, time, area, site and type of disease--and facilitating on-line evaluation of NTP implementation.

CONCLUSION

The web-based surveillance system has been well established within the existing health infrastructure, providing real-time figures on the TB burden. However, it requires continued improvement of the quality of information and of case reporting activities.

Anti-inflammatory effect of amurensin H on asthma-like reaction induced by allergen in sensitized mice

AIM

To explore the anti-inflammatory effects of amurensin H on asthma-like reaction induced by allergen in sensitized mice.

METHODS

BALB/c mice were sensitized by ovalbumin (OVA, ip) on d 0 and d 14 and challenged with 1% OVA on d 18 to 22. Mice developed airway eosinophilia, mucus hypersecretion, and elevation in cytokine levels. Mice were administered amurensin H orally at the doses of 49, 70, or 100 mg/kg once every day from d 15 to the last day. Bronchoalveolar lavage fluid (BALF) were collected at 24 h and 48 h after the last OVA challenge. Levels of tumor necrosis factor-alpha (TNF-alpha), interleukin 4 (IL-4), interleukin 5 (IL-5), and interleukin 13 (IL-13) in BALF were measured using ELISA method. Differential cell counts of macrophages, lymphocytes, neutrophils and eosinophils were performed in 200 cells per slide (one slide per animal). Lung tissue sections of 6-mum thickness were stained with Mayer's hematoxylin and eosin for assessment of cell infiltration, mucus production, and tissue damage.

RESULTS

Oral administration of amurensin H significantly inhibited OVA-induced increases in total cell counts, eosinophil counts, and TNF- alpha, IL-4, IL-5 and IL-13 levels in BALF. In addition, amuresin H dramatically decreased OVA-induced lung tissue damage and mucus production.

CONCLUSION

Amurensin H may have therapeutic potential for the treatment of allergic airway inflammation.

A novel immunostimulator, N-[alpha-O-benzyl-N-(acetylmuramyl)-L-alanyl-D-isoglutaminyl]-N6-trans-(m-nitrocinnamoyl)-L-lysine, and its adjuvancy on the hepatitis B surface antigen

N(2)-[alpha-O-benzyl-N-(acetylmuramyl)-L-alanyl-D-isoglutaminyl]-N(6)-trans-(m-nitrocinnamoyl)-L-lysine (muramyl dipeptide C, or MDP-C) has been synthesized as a novel, nonspecific immunomodulator. The present study shows that MDP-C induces strong cytolytic activity by macrophages on P388 leukemia cells and cytotoxic activity by cytotoxic T lymphocytes (CTLs) on P815 mastocytoma cells. Our results also indicate that MDP-C is an effective stimulator for production of interleukin-2 and interleukin-12 by murine bone marrow derived dendritic cells (BMDCs) and production of interferon-gamma by CTLs. Additionally, MDP-C increases the expression levels of several surface molecules, including CD11c, MHC class I, and intercellular adhesion molecule-1 in BMDCs. Moreover, MDP-C remarkably enhances the immune system's responsiveness to hepatitis B surface antigen (HBsAg) in hepatitis B virus transgenic mice for both antibody production and specific HBsAg T-cell responses ex vivo. Our results indicate that MDP-C is an apyrogenic, nonallergenic, and low-toxicity immunostimulator with great potential for diagnostic, immunotherapeutic, and prophylactic applications in diseases such as hepatitis B and cancers.

[Effect of anti-inflammatory drugs on the NF-kappaB activation of HEK293 cells]

AIM

To investigate the regulatory effects of various anti-inflammatory drugs on both endogenous and TNFalpha-induced NF-kappaB activation as well as the relative biological activity.

METHODS

HEK293 cells were cultured in 96-well plate and 6-well plate, treated with meloxicam, indomethacin, dexamethasone and hydrocortisone, without or with 10 ng.mL(-1) TNFalpha for 24 hours. Then cell proliferation was measured by MTT and cell apoptosis was analyzed by pI stain-flow cytometry. HEK293/ kappaB-luc cells transfected stably with pElam-kappaB-luc vector, were cultured in 96-well plate and treated as above. Equal amounts of cell lysates were tested for luciferase activity which represents NF-kappaB activation.

RESULTS

Endogenous NF-kappaB activation was present in HEK293 cells and its level can be increased about 2 times by 10 ng.mL(-1) TNFalpha-induction. Dexamethasone (1 x 10(-8) mol.L(-1)) and meloxicam (1 x 10(-7) - 1 x 10(-6) mol.L(-1)) can decrease both endogenous and TNFalpha-induced NF-kappaB activation. Hydrocortisone (1 x 10(-9) mol.L(-1)) increases endogenous NF-kappaB activation but decreases TNFalpha-induced one significantly. No influence of indomethacin on endogenous NF-kappaB activation was observed. However, its influence on TNFalpha-induced NF-kappaB activation is needed for further study. Cell apoptosis was observed after treatment with TNFalpha and 1 x 10(-8), 1 x 10(-6) mol.L(-1) dexamethasone and 1 x 10(-7) mol.L(-1) indomethacin, or only with dexamethasone. No significant effect of these anti-inflammatory drugs on cell proliferation was observed.

CONCLUSION

Various anti-inflammatory drugs differ in their ability to regulate NF-kappaB activation in HEK293 cells, which indicates that NF-kappaB activation might be a potential useful target to study mechanism and for drug screening.

[Effects of ginkgolide B on arachidonic acid metabolizing enzymes and level of intracellular calcium in rat polymorphonuclear leukocytes]

AIM

To investigate the effects of ginkgolide B on arachidonic acid (AA) metabolizing enzymes and the level of intracellular calcium in rat polymorphonuclear leukocytes.

METHODS

Intracellular free calcium was quantitated by Fura-2 fluorescence technique. Phospholipase A2 (PLA2) activity was determined by incorporating 3H-arachidonic acid in leukocytes. 5-Lipoxygenase (5-LO) activity was evaluated by RP-HPLC.

RESULTS

In comparison with control, ginkgolide B at final concentration of 0.1-10 mumol.L-1 inhibited A23187 induced AA release by 10.9%-22.2%; at final concentration of 0.1-50 mumol.L-1, ginkgolide B inhibited LTB4 and 5-HETE synthesis stimulated by PAF by 29.4%-88.8% and 26.2%-89.3% respectively. At the final concentration of 0.1-100 mumol.L-1, ginkgolide B decreased the rise of intracellular calcium level induced by pletelet activating factor (PAF) and N-formyl-methionine-leucine-phenglalanine (fMLP) by 13.9%-51.4% and 2.2%-36.6%, respectively.

CONCLUSION

Ginkgolide B was found to significantly inhibit PLA2 and 5-LO activities, as well as the increase of the intracellular calcium induced by PAF.

[Effects of musk glucoprotein on the function of rat polymorphonuclear leukocytes activated by IL-8 in vitro]

OBJECTIVE

To investigate the effects of musk-1, a glucoprotein component isolated from the water extract of musk, on some functions of rat polymorphonuclear leukocytes activated by IL-8 in vitro.

METHOD

An in vitro incubation system was used. Superoxide anion production was determined by cytochrome C reduction. beta-glucuronidase and lysozyme release was quantitated by enzyme reactions in which phenolph-thaleinglucuronic acid and Micrococcus Lysodeikticus were as the substrates, respectively.

RESULTS

In comparison with control, musk-1 at concentration 1-100 micrograms.ml-1 can increase superoxide anion production by 91.7%-291%, and decrease beta-glucuronidase and lysozyme release by 2.2%-58.1% and 3.9%-39.8%, respectively.

CONCLUSION

Inhibition of lysosomel enzyme release might be considered as one of mechanisms of antiinflammatory action of musk.

[Effects of musk glucoprotein on PAF production and cytosolic Ca2+ level in rat polymorphonuclear leukocytes in vitro]

OBJECTIVE

To investigate the effects of Musk glucoprotein on platelet activating factor (PAF) production and the concentration of cytosolic free Ca2+ in polymorphonuclear leukocytes of rat.

METHODS

An in vitro incubation system was used, production of PAF and activity of acetyl transferase were measured by isotope incorporation, the concentration of cytosolic free Ca2+ was quantitated using the fluorescent Ca2+ indicator Fura-2.

RESULTS

Musk-1 at concentration of 1-100 micrograms.ml-1 can significantly inhibit production of PAF, activity of acetyl transferase and the increase of cytosolic Ca2+ concentration in polymorphonuclear leukocytes of rat.

CONCLUSION

Part of mechanisms underlying antiinflammatory action of Musk-1 is through inhibiting the synthesis of PAF and the increase of cytosolic Ca2+ level.

Twenty-year trend of chronic excretors of tubercle bacilli based on the nationwide tuberculosis prevalence surveys in Korea, 1975-1995

SETTING

A study of chronic excretors of tubercle bacilli (chronic cases) based on the nationwide random sample surveys of tuberculosis prevalence conducted in Korea from 1975 through 1995.

OBJECTIVE

To investigate the temporal trend of the prevalence of chronic cases, and to match these with treatment outcomes and drug resistance rates.

DESIGN

Bacillary cases were classified by history of chemotherapy into new (those who denied a history of chemotherapy), non-chronic (those who had taken chemotherapy for less than 2 years) and chronic cases (those who had taken chemotherapy for more than 2 years).

RESULTS

Chronic cases decreased from 107 to 12 per 100000 population (annual rate of reduction [ARR] 11.89%) over the 20-year period. The ARR of chronic cases was significantly greater than that of new cases, and accelerated from 1985 (ARR 15.83%), after the application of short course chemotherapy. Rates of overall drug resistance rates increased up to 1980, and those of multidrug resistance up to 1985, followed by a decrease thereafter. A reduction in chronic cases was observed even during the period of increase in drug resistance (including multidrug resistance).

CONCLUSION

The prevalence of chronic tuberculosis cases has decreased due to improvements in overall treatment outcome.

Treatment of bacillary pulmonary tuberculosis at the chest clinics in the private sector in Korea, 1993

SETTING

Cohort study of bacillary pulmonary tuberculosis patients treated at private sector chest clinics in Korea.

OBJECTIVE

To assess the treatment behaviour of physicians in private chest clinics and the treatment outcomes of their patients.

DESIGN

1) A retrospective analysis of a cohort of patients admitted from July through October in 1993, and 2) comparison with results from health centres under the National Tuberculosis Programme (NTP).

RESULTS

Nine hundred and sixty bacillary patients (507 newly diagnosed--'new', and 453 retreatment--'old') were admitted to the study. Initial smears and cultures were not performed in 7% and 21%, and follow-up smears and cultures not done in 19% and 28%, respectively. The regimens prescribed were variable: 23 in 'new' and 72 in 'old' patients, 86 in total. Six-month short-course treatment using HRZE was prescribed for 26.2% of 'new' patients. In many instances, the planned treatment duration was excessive. The success rates (cured plus completed) for 'new' and 'old' patients were 74% and 51%, respectively. The failure rates were less than 1% in 'new' and 9% in 'old' patients.

CONCLUSION

Prescribed regimens were variable in terms of drug combinations and treatment duration. Overall treatment outcome was inferior to that of the health centres under the NTP.

Antiinflammatory effects of Tremulacin, a Salicin-related substance isolated from Populus tomentosa Carr. leaves

Tremulacin was shown to inhibit carrageenan-induced paw edema in rats and croton oil-induced ear edema in mice. It was also found to inhibit peritoneal leucocyte migration in rats and acetic acid-induced writhing responses in mice. Experiments with isolated longitudinal muscle strips of sensitized guinea pig ileum showed that tremulacin decreased the biosynthesis of Slow Reaction Substance of Anaphylaxis. Tremulacin exerted inhibitory effects on leukotriene B4 biosynthesis in intrapleural leucocytes. These results suggest that the mechanism of antiinflammatory actions of tremulacin is relevant to inhibition of 5-lipoxygenase activity. This is quite different from non-steroid antiinflammatory drugs, such as aspirin, which inhibits prostaglandin synthesis and being a cyclooxygenase inhibitor.

[Determination of glyciphosphoramide and its metabolite in plasma and the pharmacokinetics in rats after oral administration]

Glyciphosphoramide (GPA) is one of the anticancer agents belonging to the group of phosphoramide mustard. It has apparent antitumor effects in some animal models and in clinical trials against breast cancer, lymphosarcoma, uterocervical cancer and cancerous ulcer with good results. In this paper, the determination procedure of GPA and its metabolite using nitrobenzylpyridine (NBP) method is reported. The absorbance of the coloured products from the reaction of hydrolyzed or metabolized GPA with NBP was measured at 570 nm and 564 nm, respectively. The linearity of the reaction for GPA and its metabolite was established over the range of 6.25-100 micrograms/ml water or plasma. The plasma of rats and mice was found to be able to metabolize GPA to form alkylating agent (s) which react with NBP, but that of rabbits cannot. The plasma concentration-time curve of metabolite obtained after oral administration of GPA (100 mg/kg) in rats was shown to fit a two compartment open model with the following parameters: T1/2 beta = 44.5 min, T1/2 alpha = 3.16 min, T1/2 Ka = 2.14 min, T1/2Km = 0.0644 min, Tmax = 7.57 min, Cmax = 55.8 micrograms/ml, AUC = 2827. 39 micrograms/ml.min, K21 = 0.09663/min, K10 = 0.03535/min, K12 = 0.1030/min, Vc = 1.00 L/kg, Vd = 2.07 L/kg, CLt = 2.12 L/h. Kidney was found to be the main organ for GPA metabolite elimination. About one fourth of the given dose was excreted in urine within 24 h with the main portion excreted in the first 2 h.

[Study on work stress perceived by clinical nurses]

This study was designed to measure the degree of work stress perceived by clinical nurses working in psychiatric ward, and to identify the factors influencing the difference of work stress. The survey method was used and the subjects of this study consisted of 135 psychiatric nurses from 7 university hospitals and 4 provincial general hospitals. The data were collected from August 1 to 20, 1988. The instrument used for this study was PNOSS (Psychiatric Nurse Occupational Stress Scale) which was developed by Bai (1989). The confidence verification of this instrument was computed and the Cronbach alpha was 0.94050. Data were analysed by t-test and ANOVA on 5% significant level with SPSS program. The results of study were summarized as follow: 1) The degree of perceived stress among psychiatric nurses was considerably high (4.32 out of 6.00). 2) Among the stressors, inadequate staffing (5.04), hospital administration problems (4.7) and the conflict of nurse-patient relationship were identified as the stress factors with high rank of degree of stress. 3) There was significant relationship between the degree of stress and the demographic variables of nurses such as the marital status, educational level, and the motivation of working in psychiatric ward. 4) There was significant relationship between the job-related variables such as the working duration, the motivation of working and nurse's attitude toward the psychiatric patients. 5) The relationship between several stress factors and some of the demographic and the job-related variables were significantly identified.

[The development of an occupational stress management tool for psychiatric nurses]

The purpose of this study is to propose the baseline data for developing the occupational stress measurement tool for Psychiatric nurses Working in the hospital. 135 staff nurses in psychiatric unit of 11 hospital were participated during the period from August 1 to August 20, 1988. Though the pretest and literature review a questionnaire was constructed with 88 stressors which were experienced by the psychiatric nurses in the hospital. Subjects were given instruction to rate 1-6 likert type scale according to the level of stress experienced by each stressor described. Reliability of the tool was tested by Cronbach's Alpha and the result was alpha = 0.94871. Factor analysis was applied to organize 88 items together. As the result, 14 factors were obtained. The factors were; 1) Administration problem. 2) Work overload. 3) Role conflict as a profession. 4) Lack of professional knowledge and skill. 5) Conflict with nurses. 6) Conflict with other health teams. 7) Conflict in nurse-client relationship. 8) Conflict with supervisor. 9) Conflict with subordinate. 10) Low reward. 11) Scheduling problem. 12) Inappropriate physical environment. 13) Staff inadequate. 14) Inadequate of equipment.