[Epidemiological characteristics of typhoid fever in Fujian Province, 2011-2022]

Objective: To analyze the incidence trend and epidemiological characteristics of typhoid fever in Fujian Province from 2011 to 2022, and understand the high-incidence population and hotspot areas, and provide evidences to develop more targeted prevention and control measures. Methods: The surveillance data of typhoid fever during 2011-2022 in Fujian Province were obtained from the National Disease Reporting Information System and analyzed with SAS 9.4. The spatial autocorrelation analysis of typhoid fever incidence at county/district levels was performed with ArcGlS 10.8. Results: A total of 5 126 cases of typhoid fever were reported in Fujian Province from 2011 to 2022, with an average annual incidence rate of 1.10/100 000. The average annual incidence rate was 0.96/100 000 from 2011 to 2015, 1.49/100 000 from 2016 to 2019, and 0.81/100 000 from 2020 to 2022. The disease occurred all the year round, with high epidemic season from May to September. A total of 23.59% (1 209/5 126) of the cases occurred at the age of 0-4, and 9.62% (493/5 126) at the age of 5-9. The male to female ratio of the cases was 0.97∶1 (2 524∶2 602) for the whole population, 1.19∶1 (925∶777) for people under 10 years old, 0.75∶1 (1 060∶1 404) for people between 10 and 54 years old, and 1.28∶1 (539∶421) for people over 55 years old. Cases in Ningde City accounted for 30.65% (1 571/5 126) of the total cases. Most hotspots were occurred in Ningde City. Recurrent and clustered cases were found in family members. Conclusions: Typhoid fever was prevalent at a low level in Fujian Province during 2011-2022, indicating that strengthening the prevention and control measures should target key areas and populations. The incidence of typhoid fever in Fujian Province showed spatial aggregation phenomenon, and most cases gathered in Ningde City. Intensive study for the influencing factors of spatial clustering should be conducted.

[Advances in risk factors and early imaging assessment of canine impaction]

The canines play an important role in both the esthetics and function of the human body. The maxillary canines has the highest prevalence of impaction in the entire dentition, except for the third molars. Once canine impaction occurs, it can lead to the conditions such as root resorption of adjacent teeth, occlusal function interference and esthetic problems. Moreover, the treatment of canine impaction is time consuming and difficult, and it often requires multi-disciplinary involvement. Therefore, the early diagnosis and treatment of canine impaction is an urgent problem in orthodontic treatment. The etiology of canine impaction is complex and its early development is highly insidious. To assist orthodontists in the early diagnosis and treatment of canine impaction, this review summarizes and discusses the relevant risk factors associated with maxillary and mandibular canine impaction, and the commonly used radiographic assessment methods.

Microbial Communities Along 2,3,7,8-tetrachlorodibenzodioxin Concentration Gradient in Soils Polluted with Agent Orange Based on Metagenomic Analyses

The 2,3,7,8-tetrachlorodibenzodioxin (TCDD), a contaminant in Agent Orange released during the US-Vietnam War, led to a severe environmental crisis. Approximately, 50 years have passed since the end of this war, and vegetation has gradually recovered from the pollution. Soil bacterial communities were investigated by 16S metagenomics in habitats with different vegetation physiognomies in Central Vietnam, namely, forests (S0), barren land (S1), grassland (S2), and developing woods (S3). Vegetation complexity was negatively associated with TCDD concentrations, revealing the reasoning behind the utilization of vegetation physiognomy as an indicator for ecological succession along the gradient of pollutants. Stark changes in bacterial composition were detected between S0 and S1, with an increase in Firmicutes and a decrease in Acidobacteria and Bacteroidetes. Notably, dioxin digesters Arthrobacter, Rhodococcus, Comamonadaceae, and Bacialles were detected in highly contaminated soil (S1). Along the TCDD gradients, following the dioxin decay from S1 to S2, the abundance of Firmicutes and Actinobacteria decreased, while that of Acidobacteria increased; slight changes occurred at the phylum level from S2 to S3. Although metagenomics analyses disclosed a trend toward bacterial communities before contamination with vegetation recovery, non-metric multidimensional scaling analysis unveiled a new trajectory deviating from the native state. Recovery of the bacterial community may have been hindered, as indicated by lower bacterial diversity in S3 compared to S0 due to a significant loss of bacterial taxa and recruitment of fewer colonizers. The results indicate that dioxins significantly altered the soil microbiomes into a state of disorder with a deviating trajectory in restoration.

[Analysis on repetitive reporting of hepatitis B in Fujian province, 2016-2020]

Objective: To analyze the repetitive reporting of hepatitis B in Fujian province during 2016-2020, and provide evidence for the improvement of hepatitis B surveillance. Methods: The reporting cards from the China Information System for Disease Control and Prevention were collected and divided into repetitive reporting cards and non-repetitive reporting cards from the report cards collected according to the valid ID number on the cards, and the proportion of repetitive report cards and related factors were analyzed by using software SAS 9.4. Results: A total of 314 551 hepatitis B reporting cards were submitted in Fujian from 2016 to 2020, in which 90.93% (286 020/314 551) were included in the analysis. The repetitive reporting cards accounted for 10.48% (29 982/286 020). The annual proportion of the repetitive reporting cards from 2016 to 2020 was between 2.98% and 3.71%, showing an overall increasing trend year by year (Z=2.26, P=0.024). The proportions of the repetitive reporting cards in 1-5 years were 3.17%, 5.40%, 7.74%, 9.27% and 10.48%, respectively, showing an increase trend with year (Z=128.16, P<0.001). The proportions of the repetitive reporting cards in 10 areas of Fujian ranged from 5.44% to 13.48% with significant difference (χ²=2 050.41, P<0.001) and increased with the increase of reported incidence of hepatitis B (Z=26.92, P<0.001). There were significant differences in relationships between repetitive reporting proportion and sex, age and type of the cases between the areas with high incidence and low incidence of hepatitis B. Conclusions: The reported incidence of hepatitis B was seriously affected by the repetitive reporting in Fujian from 2016 to 2020. A cross-year and cross-area surveillance mechanism for hepatitis B should be established and targeted measures should be taken to strengthen the control of the repetitive reporting and improve the surveillance for hepatitis B.

[Application of trifoliate flap design of radial forearm flap in reconstruction of defects after mouth floor cancer resection]

Objective: To evaluate the effect of trifoliate flap design of radial forearm flap in reconstruction of defects after mouth floor cancer resection. Methods: From June 2016 to December 2019, 12 patients with defect after resection of mouth floor cancer were treated with trifoliate flap design of radial forearm flap. All of these patients were T2 stage, included 9 well-differentiated squamous cell carcinoma (SCC) and 3 moderate differentiated SCC. The defect size ranged from 8.0 cm×6.0 cm to 5.0 cm×4.5 cm after resection of tumor and neck dissection. All defects were repaired with trifoliate flap design of radial forearm flap. The flap size ranged from 8.0 cm×2.0 cm to 4.0 cm×1.5 cm, the donor site was sutured directly on Z plasty. Results: All flaps completely survived well. Both the wound and the donor site were stage Ⅰ healing. With the average follow-up of 38.6 months, the swallowing and speech function were satisfactory. Conclusions: Trifoliate flap design of radial forearm flap can effectively repair the postoperative defect of mouth floor cancer, and the donor site can be directly sutured on Z plasty. This technique can avoid forearm scar caused by skin grafting and the formation of the second donor site.

bFGF stimulated plasminogen activation factors, but inhibited alkaline phosphatase and SPARC in stem cells from apical Papilla: Involvement of MEK/ERK, TAK1 and p38 signaling

•

bFGF induced uPA, uPAR, PAI-1 production/expression in SCAP →

•

bFGF induced decline of ALP and SPARC of SCAP →

•

The effects of bFGF are regulated by ERK, p38, TAK1 and Akt signaling →

•

Crucial for SCAP proliferation, matrix turnover and differentiation →

•

These events are important for revascularization/root apexogenesis

Introduction

Objectives

Methods

Results

Conclusion

The effect of the COVID-19 pandemic on heart failure unplanned admission: a single center study

Background

Acute heart failure (AHF) is a leading cause of admissions among adults. The COVID-19 pandemic has placed a high burden on healthcare systems globally. Many countries announced lockdowns which restricted residents' movement. There is a reported reduction in AHF admissions during the pandemic in several countries, potentially leading to adverse outcomes such as increased morbidity and mortality. To date, little is known on whether similar trends are observed in Southeast Asian (SEA) countries.

Purpose

We aim to evaluate whether AHF admissions have been affected by the pandemic and the lockdown restrictions in a multi-ethnic, urban SEA country. We hypothesized that the pandemic and lockdown restrictions (called a “circuit breaker (CB)”) will influence heart failure (HF) admission rates.

Methods

We conducted a retrospective analysis of patients who were admitted with a principal diagnosis of HF to a tertiary hospital in a SEA country. The study period was from the first confirmed case of COVID-19 (January 23, 2020) to July 31, 2020 (n=378). This was further divided into 3 sub-periods for inter-year and intra-year subgroup analysis. Pre-CB: January 23, 2020 to April 6, 2020, CB: April 7, 2020 to June 1, 2020, and Post-CB reopening (Phase 1 & 2): June 2, 2020 to July 31, 2020. The control period was the same timeframe in the preceding year (January 23, 2019 to July 31, 2019) (n=398) and was similarly divided into 3 subgroups. The primary outcome was the overall HF admission rate. Where appropriate, Poisson regression or Negative Binomial regression was utilised to compare the incidence rate ratios of the HF admissions between the periods. Mann-Whitney test or student's t-test was used to compare the length of stay (LOS) and Charlson Comorbidity Index (CCI) scores.

Results

Details on the study cohort can be found in Table 1. The study period's overall mean admission rate was 2.08 per day, which was not significantly different from the control (2.00 per day). Subgroup analysis showed that the CB admission rates were significantly lower compared to (i) the control (1.39 per day vs. 2.02 per day) and (ii) pre-CB period in the same year (1.39 per day vs. 2.44 per day) (Fig. 1). Phase 1 & 2 admission rates were significantly higher compared to the control (2.28 per day vs. 1.68 per day), and CB admission rates (2.28 per day vs. 1.39 per day). There were no inter-year or intra-year differences for LOS. There was a significant inter-year difference in CCI scores during the CB period (CB: 2.88 vs. control: 1.97).

Conclusions

Our study showed significant decreases in AHF admissions during the CB period, and a significant increase in AHF admissions from CB to Post-CB reopening. These suggest that the lockdown restrictions had an influence on patients' health seeking behaviour. We also recognise the need to raise public awareness to encourage HF patients to seek timely treatment, prevent complications and adverse events.

Funding Acknowledgement

Type of funding sources: None.

Enhanced molybdenum(VI) removal using sulfide-modified nanoscale zerovalent iron: kinetics and influencing factors

The overall goal of this study is to investigate the effect of sulfidated nanoscale zerovalent iron (S-nZVI) on the removal of hexavalent molybdate (MoO₄^2-) under different aquatic chemistry conditions. Surface analysis suggests that Mo(VI) is removed mainly by adsorption and co-precipitation onto the surface of S-nZVI and a small amount of Mo(VI) can be reduced to Mo(V) species. The results of batch tests show that Mo(VI) removal by S-nZVI are well described with the pseudo-second-order adsorption model. The removal rate increases with a decrease in solution pH (4.0-9.0) and is significantly affected by the S/Fe ratio of S-nZVI, with the optimal S/Fe ratio being 0.5. The presence of anions WO₄^2- or CrO₄^2- can reduce the Mo(VI) removal, which is likely because they compete for adsorption sites on the solid surfaces. The divalent cations Ni²⁺, Cu²⁺ and Co²⁺ also inhibit the removal of Mo(VI) whereas Zn²⁺, Ca²⁺ and Mg²⁺ enhance it. After being aged for 35 d in water, S-nZVI still exhibits high reactivity towards Mo(VI) removal (57.39%). The study demonstrates that S-nZVI can be used as an environmentally friendly material for effectively removing Mo(VI) from contaminated water.

Effects of transforming growth factor-β1 on plasminogen activation in stem cells from the apical papilla: role of activating receptor-like kinase 5/Smad2 and mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signalling

AIM

To study the effects of TGF-β1 on the plasminogen activation (PA) system of stem cells from the apical papilla (SCAP) and its signalling.

METHODOLOGY

SCAP cells were isolated from the apical papilla of immature permanent teeth extracted for orthodontic reasons. They were exposed to various concentration of TGF-β1 with/without pretreatment and coincubation by SB431542 (ALK/Smad2/3 inhibitor), or U0126 (MEK/ERK inhibitor). MTT assay, Western blotting and enzyme-linked immunosorbent assay (ELISA) were used to detect their effects on cell viability, and the protein expression of plasminogen activator inhibitor-1 (PAI-1), urokinase-type plasminogen activator (uPA), uPA receptor (uPAR) and their secretion. The paired Student's t-test was used for statistical analysis.

RESULTS

TGF-β1 significantly stimulated PAI-1 and soluble uPAR (suPAR) secretion of SCAP cells (P < 0.05), whereas uPA secretion was inhibited. Accordingly, TGF-β1 induced both PAI-1 and uPAR protein expression of SCAP cells. SB431542 (an ALK5/Smad2/3 inhibitor) pretreatment and coincubation prevented the TGF-β1-induced PAI-1 and uPAR of SCAP. U0126 attenuated the TGF-β1-induced expression/secretion of uPAR, but not PAI-1 in SCAP. SB431542 reversed the TGF-β1-induced decline of uPA.

CONCLUSIONS

TGF-β1 may affect the repair/regeneration activities of SCAP via differential increase or decrease of PAI-1, uPA and uPAR. These effects induced by TGF-β1 are associated with ALK5/Smad2/3 and MEK/ERK activation. Elucidation the signalling pathways and effects of TGF-β1 is useful for treatment of immature teeth with open apex by revascularization/revitalization procedures and tissue repair/regeneration.

[Complete mitochondrial genomes of Paragonimus westermani in China and phylogenetic analysis of various geographical isolates]

OBJECTIVE

To compare the complete mitochondrial genome sequences of two phenotypes of Paragonimus westermani isolated from Fujian Province with different sizes of metacercariae, and perform a phylogenetic analysis of various geographical isolates of P. westermani from Asia, so as to identify the possible genetic characteristics associated with the P. westermani phenotypes.

METHODS

P. westermani metacercariae with different sizes (large metacercariae, 380-420 μm in diameter; small metacercariae, 320-340 μm) isolated from freshwater crabs were used to infect dogs, and the eggs and adult worms of P. westermani were collected from the dog stool samples and lung tissues. Then, the egg size and morphology were compared. In addition, genomic DNA was extracted from the adult worms of the two phenotypes of P. westermani and used for the PCR amplification to yield the complete mitochondrial genome sequence. Sequence structure and phylogenetic analyses were performed based on the complete mitochondrial genome of P. westermani.

RESULTS

Following infection with large and small P. westermani metacercariae, the adult worms recovered from the dog lung had a thick body, and had oral and ventral suckers. The ventral sucker was located slightly in front of the midline of the body, and testes, ovary and vitelline gland were seen in the adult worms. Following fixation, the adults appeared oval, with an approximately 1.7∶1 of the length-width ratio. The length and width of the eggs isolated from the fecal samples of dogs infected with large and small P. westermani metacercariae varied significantly, and the large metacercariae produced bigger eggs than the smaller metacercariae. Based on the morphological features of adults and eggs and the ITS2 sequences, both phenotypes were identified as P. westermani. The complete mitochondrial genome sequence analysis of adults showed almost consistent sequences in the protein-coding region of the mitochondrial genome of adult worms derived from large and small metacercariae, with a major variation seen in the former non-coding region. Sliding window analysis revealed the most polymorphic region within the ND4 gene across the mitochondrial genome from various geographical isolates of P. westermani, and phylogenetic analysis showed that both phenotypes were clustered into the Chinese branch of P. westermani, which was close to the Japanese branch and distinct from the South/Southeast Asian branch.

CONCLUSIONS

The genetic distance between the phenotypes of P. westermani isolated from Fujian Province is near at a mitochondrial genome level, with no remarkable genetic differentiation seen; however, the mutation and structural changes in the non-coding region may result in the phenotypic variations. In addition, there is a distinct variation of the evolutionary rate in the mitochondrial coding genes, suggesting the selection of appropriate molecular markers during the phylogenic researches.

[Analysis on association between incidence of hand foot and mouth disease and meteorological factors in Xiamen, 2013-2017]

Objective: To study the influence of meteorological factors on the incidence of hand foot and mouth disease (HFMD) in Xiamen, Fujian province, and provide scientific evidence for the early warning, prediction, prevention and control of HFMD. Methods: Correlation analysis and distribution lag nonlinear models (DLNM) analysis of meteorological factors such as daily average pressure, daily average relative humidity, daily average temperature and sunshine hours and the incidence of HFMD in Xiamen during 2013 to 2017 were conducted by using R3.4.3 software. Results: A total of 36 464 cases of HFMD were reported in Xiamen during 2013-2017, and the incidence showed an upward trend (F=40.359, P=0.008). The daily average relative humidity, daily average temperature and sunshine hours were positively correlated with the incidence of HFMD (r>0), and the daily average site pressure was negatively correlated with the incidence of HFMD (r<0). In the case of a lag of 0-5 days, when the daily average pressure of the station was higher than 1 005 hPa, the risk of HFMD gradually increased with the increase of air pressure, and the risk of disease decreased with the increase of lag days. The risk was highest when air pressure was 1 017 hPa and at the lag of 0 day (RR=1.14, 95%CI: 0.67-1.94). When the relative humidity was higher than 95%, the risk of HFMD gradually increased with the increase of relative humidity, and the lag time ranged from 0 day to 10 days, which was most obvious on the 4(th) and 5(th) days. The risk was highest when relative humidity was 100% and at the lag of 5 days (RR=1.32, 95%CI: 1.02-1.71). When the air temperature was >28 ℃ and <8 ℃, the risk of HFMD existed, but the lag time was inconsistent. The relative risk was highest during 15-20 days at low air temperature, and the lag time at high air temperature was mainly during 5-15 days. The risk was highest when air temperature was 28 ℃ and at the lag of 4 days (RR=1.10, 95%CI: 0.94-1.29). The sunshine time was >12 h and lag of 0-3 days was a risk factor for the incidence of HFMD. The risk was highest when sunshine time was 13 h and the lag of 0 day (RR=1.20, 95%CI: 1.05-1.36). Conclusion: Meteorological factors such as daily average pressure, daily average relative humidity, daily average temperature and sunshine hours were associated with the incidence of HFMD with certain lag in Xiamen. So, it is suggested to use these data in the early warning system of HFMD.

[Survival analysis of people living with HIV/AIDS in Sichuan province, 1991-2017]

Objective: To analyze the survival time of people living with HIV/AIDS and related influencing factors in Sichuan province during 1991-2017. Methods: A retrospective cohort study was conducted to analyze the data of 143 988 HIV/AIDS cases. The data were collected from Chinese HIV/AIDS Comprehensive Information Management System. Life table method was used to calculate the survival proportion of the cases, and Cox proportion hazard regression model was used to identify the factors related with survival time. Results: Among 143 988 HIV/AIDS cases a total of 30 420 cases died of AIDS related diseases (21.1%) and the average survival time was 11.51 years (95%CI: 11.39-11.64). Multivariate Cox regression analysis showed that the influencing factors for the survival of HIV/AIDS cases were gender (male vs. female, HR=1.35, 95%CI: 1.32-1.40), education level (primary school or below vs. junior middle school: HR=1.15, 95%CI: 1.12-1.18), ethnic group (Han vs. other ethnic groups, HR=1.46, 95%CI: 1.41-1.52), occupation (farmer vs. other occupations: HR=1.26, 95%CI: 1.22-1.29), age (≥55 years old vs. 15-24 years old: HR=3.18, 95%CI: 3.02- 3.36), disease phase (AIDS vs. HIV infection: HR=1.44, 95%CI: 1.39-1.48), antiretroviral therapy (ART) (receiving ART vs. receiving no ART: HR=0.20, 95%CI: 0.19-0.20), and CD(4)(+)T cell counts at diagnosis (>500 cells/μl vs.<200 cells/μl: HR=0.42, 95%CI: 0.40-0.45). Conclusions: The average survival time of HIV/AIDS cases was 11.51 years in Sichuan during 1991- 2017. The risk factors for the survival of the cases were male, education level of primary school or below, Han ethnic group, farmer, old age at diagnosis, disease phase, The protective factors for the survival of HIV/AIDS cases were receiving ART and higher CD(4)(+) T cell counts at diagnosis.

Butyrate Stimulates Histone H3 Acetylation, 8-Isoprostane Production, RANKL Expression, and Regulated Osteoprotegerin Expression/Secretion in MG-63 Osteoblastic Cells

Butyric acid as a histone deacetylase (HDAC) inhibitor is produced by a number of periodontal and root canal microorganisms (such as Porphyromonas, Fusobacterium, etc.). Butyric acid may affect the biological activities of periodontal/periapical cells such as osteoblasts, periodontal ligament cells, etc., and thus affect periodontal/periapical tissue destruction and healing. The purposes of this study were to study the toxic effects of butyrate on the matrix and mineralization marker expression in MG-63 osteoblasts. Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cellular apoptosis and necrosis were analyzed by propidium iodide/annexin V flow cytometry. The protein and mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) were analyzed by Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). OPG, soluble RANKL (sRANKL), 8-isoprostane, pro-collagen I, matrix metalloproteinase-2 (MMP-2), osteonectin (SPARC), osteocalcin and osteopontin (OPN) secretion into culture medium were measured by enzyme-linked immunosorbant assay. Alkaline phosphatase (ALP) activity was checked by ALP staining. Histone H3 acetylation levels were evaluated by immunofluorescent staining (IF) and Western blot. We found that butyrate activated the histone H3 acetylation of MG-63 cells. Exposure of MG-63 cells to butyrate partly decreased cell viability with no marked increase in apoptosis and necrosis. Twenty-four hours of exposure to butyrate stimulated RANKL protein expression, whereas it inhibited OPG protein expression. Butyrate also inhibited the secretion of OPG in MG-63 cells, whereas the sRANKL level was below the detection limit. However, 3 days of exposure to butyrate (1 to 8 mM) or other HDAC inhibitors such as phenylbutyrate, valproic acid and trichostatin stimulated OPG secretion. Butyrate stimulated 8-isoprostane, MMP-2 and OPN secretion, but not procollagen I, or osteocalcin in MG-63 cells. Exposure to butyrate (2⁻4 mM) for 3 days markedly stimulated osteonectin secretion and ALP activity. In conclusion, higher concentrations of butyric acid generated by periodontal and root canal microorganisms may potentially induce bone destruction and impair bone repair by the alteration of OPG/RANKL expression/secretion, 8-isoprostane, MMP-2 and OPN secretion, and affect cell viability. However, lower concentrations of butyrate (1⁻4 mM) may stimulate ALP, osteonectin and OPG. These effects are possibly related to increased histone acetylation. These events are important in the pathogenesis and repair of periodontal and periapical destruction.

Clinical efficacy of low dose recombinant tissue-type plasminogen activator for the treatment of acute intermediate-risk pulmonary embolism

OBJECTIVES

To investigate the efficacy and safety of initial thrombolysis by recombinant tissue-type plasminogen activator (rt-PA) in compared with anticoagulant therapy in patients with acute intermediate-risk pulmonary embolism (PE).  Methods: Sixty-six patients with acute intermediate-risk PE were randomly assigned to receive rt-PA or LMWH between June 2014 and June 2017 in our department. We obtained information regarding the difference in the right ventricle/left ventricle (RV/LV) ratio, pulmonary artery systolic pressure (PASP), clinical symptoms improvement, PE-related mortality, hemodynamic decompensation, recurrent PE, and major and minor bleeding.  Results: In the rt-PA group, the mean PASP was reduced from 52.0±12.2 at baseline to 34.8±9.4 (p less than 0.001) and the mean RV/LV ratio was reduced from 1.26±0.22 at baseline to 0.96±0.18 (p less than 0.001) at 24 hours. In the LMWH group, the mean PASP was 53.4±12.8 at baseline and 48.5±11.9 at 24 hours (p=0.11), and the mean RV/LV ratio was 1.22±0.19 at baseline and 1.17±0.21 at 24 hours (p=0.31). In comparison with the LMWH group, there was a significant reduction in PASP and an improvement in the symptom severity in the rt-PA group. At 90 days, there was no difference in mortality, recurrent venous thromboembolism and major bleeding as a safety outcome, but increased minor bleeding and decreased hemodynamic decompensation occurred in the rt-PA group. Conclusions: In patients with acute intermediate-risk PE, low dose thrombolytic therapy is considered safe and effective, it can be recommended as an alternative option in clinical treatment.

Vitamin D and new-onset atrial fibrillation: A meta-analysis of randomized controlled trials

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, which affects 1.5% to 2% of the general population. More than six million Europeans suffer from AF. To research vitamin D levels in the prevention of new-onset atrial fibrillation (AF), we conducted a systematic review of randomized controlled trials (RCTs). We focused on the vitamin D levels in the prevention of new-onset AF. The outcomes assessed were vitamin D levels, left ventricular ejection fraction (LVEF), and left atrium diameter. Six RCTs ultimately met the inclusion criteria in the meta-analysis. The outcomes of Vitamin D levels (MD = -4.27, 95% CI = -5.20 to-3.34, P = 0.30) in the new-onset AF showed no significant difference. The left atrium diameter (MD = 1.96, 95% CI = 1.48 to 2.60, P < 0.01) between new-onset AF and LVEF (MD = -0.92, 95% CI = -1.59 to -0.26, P < 0.01) showed significant difference. Our study shows that circulating vitamin D levels may not play a major role in the development of new-onset AF.

Lysophosphatidylcholine induces cytotoxicity/apoptosis and IL-8 production of human endothelial cells: Related mechanisms

Increased levels of oxidized low-density lipoprotein oxLDL) are shown to elevate the risk of cardiovascular diseases such as atherosclerosis, thrombosis, stroke, and myocardial infarction. This is possibly due to the toxic effects of oxLDLs on vascular cells. Various oxLDLs including lysophosphatidylcholine (LPC) and 7-ketocholesterol injure vascular endothelial cells and stimulate inflammatory reaction. However the toxicity of LPC on endothelial cells is not clear. In this study, human endothelial cells were exposed to LPC. Cytotoxicity was measured by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. Propidium iodide (PI) staining or PI/Annexin V dual staining flow cytometry were used to determine cell cycle progression and apoptosis. Reactive oxygen species (ROS) level was analyzed by DCFH-DA labeling flow cytometry. RNA and protein expression of endothelial cells was studied by reverse transcriptase-polymerase chain reaction and western blotting. IL-8 secretion was measured by enzyme-linked immunosorbant assay. LPC showed cytotoxicity to endothelial cells (>50 µg/ml). LPC induced cell cycle arrest and apoptosis with concomitant inhibition of cdc2 and cyclin B1 expression. LPC stimulated intracellular ROS production and ATM/Chk2, ATR/Chk1 and Akt activation. IL-8 expression and secretion in endothelial cells were induced by LPC. LPC-induced apoptosis, and IL-8 expression/secretion was attenuated by LY294002, a PI3K/Akt inhibitor. These results reveal that LPC is involved in the pathogenesis of atherosclerosis and vascular diseases by stimulation of inflammation and injury to endothelial cells. These events are related to ROS, ATM/Chk2, ATR/Chk2 and PI3K/Akt signaling. Understanding the toxic mechanisms of LPC is useful for future prevention and treatment atherosclerosis.

Basic Fibroblast Growth Factor Regulates Gene and Protein Expression Related to Proliferation, Differentiation, and Matrix Production of Human Dental Pulp Cells

INTRODUCTION

Basic fibroblast growth factor (bFGF) plays differential effects on the proliferation, differentiation, and extracellular matrix turnover in various tissues. However, limited information is known about the effect of bFGF on dental pulp cells. The purposes of this study were to investigate whether bFGF influences the cell differentiation and extracellular matrix turnover of human dental pulp cells (HDPCs) and the related gene and protein expression as well as the role of the mitogen-activated protein kinase (MEK)/extracellular-signal regulated kinase (ERK) signaling pathway. The expression of fibroblast growth factor receptors (FGFRs) in HDPCs was also studied.

METHODS

The expression of FGFR1 and FGFR2 in HDPCs was investigated by reverse-transcription polymerase chain reaction. HDPCs were treated with different concentrations of bFGF. Cell proliferation was evaluated using the 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Cell differentiation was evaluated using alkaline phosphatase (ALP) staining. Changes in messenger expression of cyclin B1 and tissue inhibitor of metalloproteinase (TIMP) 1 were determined by reverse-transcription polymerase chain reaction. Changes in protein expression of cdc2, TIMP-1, TIMP-2, and collagen I were determined by Western blotting. U0126 was used to clarify the role of MEK/ERK signaling.

RESULTS

HDPCs expressed both FGFR1 and FGFR2. Cell viability was stimulated by 50-250 ng/mL bFGF. The expression and enzyme activities of ALP were inhibited by 10-500 ng/mL bFGF. At similar concentrations, bFGF stimulates cdc2, cyclin B1, and TIMP-1 messenger RNA and protein expression. bFGF showed little effect on TIMP-2 and partly inhibited collagen I expression of pulp cells. U0126 (a MEK/ERK inhibitor) attenuated the bFGF-induced increase of cyclin B1, cdc2, and TIMP-1.

CONCLUSIONS

bFGF may be involved in pulpal repair and regeneration by activation of FGFRs to regulate cell growth; stimulate cdc2, cyclin B1, and TIMP-1 expression; and inhibit ALP. These events are partly associated with MEK/ERK signaling.

Extract of Ginkgo biloba promotes neuronal regeneration in the hippocampus after exposure to acrylamide

Previous studies have demonstrated a neuroprotective effect of extract of Ginkgo biloba against neuronal damage, but have mainly focused on antioxidation of extract of Ginkgo biloba. To date, limited studies have determined whether extrasct of Ginkgo biloba has a protective effect on neuronal damage. In the present study, acrylamide and 30, 60, and 120 mg/kg extract of Ginkgo biloba were administered for 4 weeks by gavage to establish mouse models. Our results showed that 30, 60, and 120 mg/kg extract of Ginkgo biloba effectively alleviated the abnormal gait of poisoned mice, and up-regulated protein expression levels of doublecortin (DCX), brain-derived neurotrophic factor, and growth associated protein-43 (GAP-43) in the hippocampus. Simultaneously, DCX- and GAP-43-immunoreactive cells increased. These findings suggest that extract of Ginkgo biloba can mitigate neurotoxicity induced by acrylamide, and thereby promote neuronal regeneration in the hippocampus of acrylamide-treated mice.

Expression of miRNA-210 in gastric cancer cell lines and its function prediction

AIM: To screen microRNAs (miRNAs) associated with metastasis of gastric cancer (GC) by miRNA microarray and to explore the possible role of miRNA-210 in GC metastasis by bioinformatics.

METHODS: GC cell lines with low (RF1) or high metastatic potential (RF48) were used for miRNA expression profiling using human miRNA microarray. Expression of miRNA-210 in 7 GC cell lines was detected by RT-PCR. MiRNA-210 targets were obtained using miRWalk, and functions of these targets in GC were predicted with David online.

RESULTS: Compared with RF1 cells, 21 and 15 miRNAs were up-regulated and down-regulated in RF48 cells, respectively. Expression of miRNA-210 was further validated by real-time quantitative RT-PCR in multiple GC cell lines with different metastatic potential, which showed that miRNA-210 was overexpressed in GC cell lines with high metastatic potential. Bioinformatics analysis suggested that miRNA-210 was related with tumorgenesis and metastasis.

CONCLUSION: Screening miRNAs associated with metastasis lays a foundation for identifying early diagnostic markers and new therapeutic targets for GC metastasis. Expression profile of miRNAs associated with metastasis was obtained by miRNA microarray; dysregulated expression of miRNA-210 may be related with GC metastasis, and may serve as an early diagnostic biomarker and new treatment target.

Fibroin protein/chitosan scaffolds and bone marrow mesenchymal stem cells culture in vitro

A previous experiment demonstrated that fibroin protein and chitosan mixed in proper proportion presented good physical and chemical properties and biological characteristics, which can make up for their respective disadvantages. To observe the growth of bone marrow mesenchymal stem cells (BMSCs) on these fibroin protein/chitosan 3D scaffolds, induced rabbit BMSCs were seeded on fibroin protein/chitosan scaffolds. The cell adhesion rate was measured, and cell growth was observed under an inverted microscope and a scanning electron microscope. The cell adhesion rate increased with time. The inverted microscope observations showed that the cells on fibroin protein/chitosan scaffolds could not be seen clearly. As time passed, the number of cells around the stent increased and some cells stretched inside the scaffolds. Electron microscopy showed active cell growth and normal proliferation, and the granular and filamentous matrix substances could be seen around cells. The microfilaments of cell and scaffold materials were tightly connected. The cells not only grew on the surface of the adherent material, but also stretched inside of the materials. These results indicated that the fibroin protein/ chitosan mixed scaffolds have good biocompatibility.

The characteristics of neuronal injury in a static compression model of spinal cord injury in adult rats

Studies of spinal cord injury using contusion (impact) injury paradigms have shown that neuronal death is an acute event that is largely over within 24 h. However, much less is known about cell death following compression injury, despite compression being a key component of natural spinal injuries. We have therefore used neuronal nuclei (NeuN) immunostaining to examine the spatiotemporal pattern of neuronal loss after static compression injury in adult rats. 3D reconstruction was used to reveal the full effect of the injury. Neuronal loss at the injury epicentre, assessed by NeuN immunostaining, amounted to 44% at 1 day but increased to 73% at 3 days and 81% at 1 month. Neuronal loss was also seen 5 mm rostral and caudal to the epicentre, but was not significant until 3 days. NeuN loss was greatest in the ventral horns and in the intermediate grey matter, with the lateral dorsal horns relatively spared. Cystic cavities formed after injury, but were not evident until 4 weeks and were small in size. In contrast to the slow profile of neuronal loss, the compression injury also evoked a transient expression of activating transcription factor-3 (ATF3) and activated c-Jun in neurons. ATF3 expression peaked at 3 days and declined at 7 days. Our spatiotemporal analysis of compression injury shows that neuronal loss is much more protracted than in contusion injury, and highlights the potential for neuroprotective strategies. This study is also the first indication of ATF3 involvement in spinal cord injury.

A combination of intravenous and dietary docosahexaenoic acid significantly improves outcome after spinal cord injury

Previous studies have shown that omega-3 polyunsaturated fatty acids such as alpha-linolenic acid and docosahexaenoic acid (DHA) are neuroprotective in models of spinal cord injury (SCI) in rodents. However, the mechanism of action underlying these effects has not been elucidated, and the optimum treatment regime remains to be defined. We have therefore carried out a detailed analysis of the effects of DHA in adult rats subject to thoracic compression SCI. Saline or DHA (250 nmol/kg) was administered intravenously (i.v.) 30 min after compression. After injury, the saline group received a standard control diet for 1 or 6 weeks, whereas DHA-injected animals received either a control or a DHA-enriched diet (400 mg/kg/day) for 1 or 6 weeks. Other groups received a DHA-enriched diet only for 1 week following injury, or received acute DHA (250 nmol/kg; i.v.) treatment delayed up to 3 h after injury. We also assessed oxidative stress and the inflammatory reaction at the injury site, neuronal and oligodendrocyte survival and axonal damage and the locomotor recovery. At 24 h, lipid peroxidation, protein oxidation, RNA/DNA oxidation and the induction of cyclooxygenase-2 were all significantly reduced by i.v. DHA administration. At 1 week and 6 weeks, macrophage recruitment was reduced and neuronal and oligodendrocyte survival was substantially increased. Axonal injury was reduced at 6 weeks. Locomotor recovery was improved from day 4, and sustained up to 6 weeks. Rats treated with a DHA-enriched diet in addition to the acute DHA injection were not significantly different from the acute DHA-treated animals at 1 week, but at 6 weeks showed additional improvements in both functional and histological outcomes. DHA treatment was ineffective if the acute injection was delayed until 3 h post-injury, or if the DHA was administered for 1 week solely by diet. Our results in a clinically relevant model of SCI show that significant neuroprotection can be obtained by combining an initial acute i.v. injection of DHA with a sustained dietary supplementation. Given that the safety and tolerability of preparations enriched in omega-3 fatty acids is already well-documented, such a combined DHA treatment regime deserves consideration as a very promising approach to SCI management.

Total sleep deprivation inhibits the neuronal nitric oxide synthase and cytochrome oxidase reactivities in the nodose ganglion of adult rats

Sleep disorders are a form of stress associated with increased sympathetic activity, and they are a risk factor for the occurrence of cardiovascular disease. Given that nitric oxide (NO) may play an inhibitory role in the regulation of sympathetic tone, this study set out to determine the NO synthase (NOS) reactivity in the primary cardiovascular afferent neurons (i.e. nodose neurons) following total sleep deprivation (TSD). TSD was performed by the disc-on-water method. Following 5 days of TSD, all experimental animals were investigated for quantitative nicotinamine adenine dinucleotide phosphate-diaphorase (NADPH-d, a co-factor of NOS) histochemistry, neuronal NOS immunohistochemistry and neuronal NOS activity assay. In order to evaluate the endogenous metabolic activity of nodose neurons, cytochrome oxidase (COX) reactivity was further tested. All the above-mentioned reactivities were objectively assessed by computerized image analysis. The clinical significance of the reported changes was demonstrated by alterations of mean arterial blood pressure (MAP). The results indicated that in normal untreated rats, numerous NADPH-d/NOS- and COX-reactive neurons were found in the nodose ganglion (NG). Following TSD, however, both the labelling and staining intensity of NADPH-d/NOS as well as COX reactivity were drastically reduced in the NG compared with normal untreated ganglions. MAP was significantly higher in TSD rats (136+/-4 mmHg) than in normal untreated rats (123+/-2 mmHg). NO may serve as an important sympathoinhibition messenger released by the NG neurons, and decrease of NOS immunoexpression following TSD may account for the decrease in NOS content. In association with the reduction of NOS activity, a defect in NOS expression in the primary cardiovascular afferent neurons would enhance clinical hypertension, which might serve as a potential risk factor in the development of TSD-relevant cardiovascular disturbances.

Spinal cord compression and dorsal root injury cause up-regulation of activating transcription factor-3 in large-diameter dorsal root ganglion neurons

Spinal cord injury causes damage to ascending and descending tracts, as well as to local circuits, but relatively little is known about the effect of such injury on sensory neurons located within adjoining ganglia. We have therefore used immunocytochemistry for activating transcription factor-3 (ATF3), a sensitive marker of axonal damage, in order to examine the effects of spinal cord injury in rats on dorsal root ganglion (DRG) neurons. A 50-g static compression injury applied to the dorsal surface of the T12 thoracic spinal cord led to an up-regulation of ATF3 that was maximal at 1 day and affected 12-14% of DRG neurons in ganglia caudal to the injury (T13-L3). A similar response was seen after a T12 hemisection that transected the dorsal columns except that compression injury, but not hemisection, also evoked ATF3 expression in ganglia just rostral to the injury (T10, T11). ATF3 was up-regulated exclusively in DRG neurons that were of large diameter and immunoreactive for heavy neurofilament. Small-diameter cells, including the population that binds the lectin Grifffonia simplicifolia IB4, did not express ATF3 immunoreactivity. A similar pattern of ATF3 expression was induced by dorsal rhizotomy. The data show for the first time that ATF3 is up-regulated after spinal cord and dorsal root injury, but that this up-regulation is confined to the large-diameter cell population.

Hypoxia-induced apoptosis in adult rat dorsal root ganglion neurons in vitro

Following spinal root injury, dorsal root ganglia suffer mechanical trauma and compromised blood supply. Little is known about the consequences for neuronal survival. Here we used cyanide treatment in vitro to examine effects of moderate hypoxia on adult rat dorsal root ganglion cells identified by GAP-43 immunostaining. 400 microM-4 mM cyanide caused sustained increases in intracellular Ca2+. Cyanide at 2 mM led to a significant increase in apoptosis, detected using TUNEL labelling and confirmed by ultrastructural analysis, and a further increase when cultures were left overnight in fresh medium. Our study shows that dorsal root ganglion neurons die by apoptosis following hypoxia and that cell death increases over time. Cyanide response provides a simple assay for testing neuroprotective agents and examining underlying mechanisms.

Dysfunctional oligodendrocyte progenitor cell (OPC) populations may inhibit repopulation of OPC depleted tissue

We have attempted to extend a previously described rat model of focal oligodendrocyte progenitor cell (OPC) depletion, using 40 Gy X-irradiation (Chari and Blakemore [2002] Glia 37:307-313), to the adult mouse spinal cord, to examine the ability of OPCs present in adjacent normal areas to colonise areas of progenitor depletion. In contrast to rat, OPCs in the mouse spinal cord appeared to be a comparatively radiation-resistant population, as 30-35% of OPCs survived in X-irradiated tissue (whereas <1% of OPCs survive in X-irradiated rat spinal cord). The numbers of surviving OPCs remained constant with time indicating that this population was incapable of regenerating itself in response to OPC loss. Additionally, these OPCs did not contribute to remyelination of axons when demyelinating lesions were placed in X-irradiated tissue, suggesting that the surviving cells are functionally impaired. Importantly, the length of the OPC-depleted area did not diminish with time, as would be expected if progressive repopulation of OPC-depleted areas by OPCs from normal areas was occurring. Our findings therefore raise the possibility that the presence of a residual dysfunctional OPC population may inhibit colonisation of such areas by normal OPCs.

Repeated prenatal corticosteroid administration delays astrocyte and capillary tight junction maturation in fetal sheep

Glucocorticoids are powerful regulators of cell differentiation and maturation. Their synthetic counterparts, the corticosteroids, are used widely in obstetric practice to enhance fetal lung maturation in cases of threatened preterm birth. Here we examined the effects of repeated corticosteroid administration on astrocyte and capillary tight junction development in the fetal sheep brain, selecting the corpus callosum for analysis. Pregnant ewes were given saline or betamethasone (0.5 mg/kg) at 104, 111, 118 and 124 days gestation. Lambs were delivered at term, terminally anaesthetized and transcardially perfused. Transverse semi-thin sections of the corpus callosum were cut and immuno-stained with antibody against glial fibrillary acidic protein (GFAP). Ultra-thin sections were examined in the electron microscope. The percentage area of GFAP staining was reduced in the corticosteroid-treated group compared to control (5.2 vs. 8.7%, P<0.05). The expression of GFAP in peri-capillary and parenchymal astrocytes was also reduced compared to control (peri-capillary: 3.0 vs. 9.5 microm2; parenchymal: 14.6 vs. 29.4 microm2, P<0.05). Furthermore, capillary tight junction maturation was delayed compared to control. Immature 'type II' junctions were more common in the corticosteroid-treated group (63 vs. 22%, P<0.05), whereas more mature 'type III' junctions were less common (27 vs. 65%, P<0.05). Our data suggest that repeated corticosteroids delay both astrocyte and capillary tight junction maturation. The implications for clinical practice are as yet unknown.

Genetic analysis of recent Taiwanese isolates of a variant of coxsackievirus A24

Epidemics of acute hemorrhagic conjunctivitis (AHC) caused by a variant of coxsackievirus A24 (CA24v) reappeared in Taiwan in 1990 and 1994, following the first two epidemics of 1985--86 and 1988--89. To analyze the genetic diversity of recent CA24v in Taiwan, 7 Taiwanese strains isolated during the 1990--94 period were studied together with one Japanese and two Thai strains isolated in 1993. A fragment of 674 nucleotides between the carboxy terminal 3A and the amino terminal 3D polymerase, including the entire 3C protease (3C(pro)), was amplified by a reverse transcription-polymerase chain reaction (RT-PCR) and the nucleotide sequences were determined. In the 549 nucleotides (183 amino acids) of the entire 3C(pro), we found nucleotide differences at 80 positions between 10 strains and the prototype strain, EH24/70, one of the earliest strains of CA24v. Most of the nucleotide changes were synonymous substitutions and only nine amino acid changes were found. The nucleotide sequence homologies among 71 strains worldwide were 88-100%. These 71 nucleotide sequences were then analyzed by Neighbor-joining method and phylogenetically separated into three distinct genotypes. Genotype I consisted of early strains isolated in 1970--71 from Singapore and Hong Kong. Genotype II included isolates from Singapore and Thailand obtained in 1975. Genotype III comprised strains from the eastern hemisphere isolated in 1985--94 from Japan, Taiwan, China, Hong Kong, Thailand, Singapore, Pakistan and Ghana. They were further divided chronologically into six clusters. The recent isolates from Taiwan obtained in 1985/1986, 1988/1989 and 1990--94 were classified into genotype III Clusters 1, 5, and 6 respectively. The evolutionary rate was re-estimated to be 3 x 10(- 3) 30 years after the emergence of the virus.

Repeated prenatal corticosteroid administration delays myelination of the corpus callosum in fetal sheep

Glucocorticoids regulate oligodendrocyte maturation and the myelin biosynthetic pathways. Synthetic glucocorticoids, the corticosteroids have been successfully used in clinical practice as a single course to enhance lung maturation and reduce mortality and morbidity in preterm infants with no long-term neurologic or cognitive side effects. However, a trend has arisen to use repeated courses despite an absence of safety data from clinical trials. We examined the effects of clinically appropriate, maternally administrated, repeated courses of corticosteroids on myelination of the corpus callosum using sheep as a large animal model. The corpus callosum is a major white matter tract that undergoes protracted myelination, underpins higher order cognitive processing and developmental damage to which is associated with, for example, cerebral palsy, mental retardation and attention deficit hyperactivity disorder. Pregnant ewes were given saline or betamethasone (0.5 mg/kg) at 104,111,118 and 124 days gestation, stages equivalent to the third trimester in humans. Lambs were delivered at 145 days (term), perfused and the corpus callosum examined light and electron microscopically. Total axon numbers were unaffected (P>0.05). However, myelination was significantly delayed. Myelinated axons were 5.7% in the experimental group and 9.2% in controls (P<0.05); conversely, unmyelinated axons were 88.3 and 83.7% (P<0.05). Myelinated axon diameter and myelin sheath thickness were also reduced (0.68 vs. 0.94 and 0.11 vs. 0.14 microm, P<0.05). Our data suggest that repeated prenatal corticosteroid administration delays myelination of the corpus callosum and that further safety data are needed to evaluate clinical practice.

[Synthesis and bioactivity of some 3,4-diacyloxybenzopyrans]

Considerable attention is now being given to the potassium channel openers of benzopyrans as potential therapeutical agents for hypertension. In order to search for novel antihypertensive with high efficacy and low toxicity, integrating structural features of cromakalim and praeruptorin C, twenty-four compounds of 3,4-diacyloxybenzopyrans were designed and synthesized. Some of them exhibited hypotensive activity in Sprague Dawley rats.

Influence of Calcination Procedure on Porosity and Surface Fractal Dimensions of Silica Xerogels Prepared under Different Evaporation Conditions

Silica xerogels were prepared under three different solvent evaporation conditions before gelation and two calcination procedures after aging and drying, using a hydrochloric acid-catalyzed tetraethyl orthosilicate system with acetone as the solvent. The influence of calcination procedures on the percentage porosity and surface fractal dimensions of the resultant xerogels is investigated. The evaluation of percentage porosity and surface fractal dimensions based on field emission gun-scanning electron microscopy indicates that calcination generally causes an increase in percentage porosity and surface fractal dimensions. Calcination at 700 degrees C without an intermediate stay at 600 degrees C leads to larger extent of further condensation that hinders the increase of porosity and surface fractal dimensions, in comparison with calcination with an intermediate stay. The difference in porosity and surface fractal dimensions derived from calcination procedures is also influenced by the solvent evaporation conditions before gelation in preparation of the samples. When the solvent evaporation rate is slower, the difference is slight because further condensation in the resultant finer gel textures proceeds more efficiently. Copyright 2000 Academic Press.

Effect of corticosteroids on brain growth in fetal sheep

OBJECTIVE

To compare the effects of single and repeated courses of corticosteroids on brain growth in fetal sheep.

METHODS

Pregnant sheep were given intramuscular betamethasone (0.5 mg/kg) at 104 days' gestation followed at 111, 118, and 124 days by equivalent volumes of sterile normal saline (n = 12) or betamethasone (n = 12). Controls received equivalent volumes of sterile normal saline at all four intervals (n = 12). Lambs were delivered at 125 (preterm) or 145 (term) days. After perfusion, we measured weights (grams) for whole brain, cerebrum, cerebellum, and brain stem, volumes (milliliters) for whole brain and cerebrum, and maximum cerebral anterior-posterior length, width, and depth (centimeters).

RESULTS

In the single-injection group at preterm, there were no significant differences (P = .070) in whole-brain weight between the corticosteroid-treated animals (38.0 +/- 1.81 g) and controls (42.5 +/- 1.65 g). Cerebral length and depth were significantly reduced in the corticosteroid group (P < .05); other measures were not significantly different. At term, whole-brain weight was significantly lower (47.5 +/- 1.70 g; P = .022) compared with controls (53.4 +/- 1.73 g). All other measures were significantly reduced (P < .05) except cerebral and brain-stem weights and cerebral length. In the group that received repeated injections at preterm, whole-brain weight was significantly reduced (35.5 +/- 1.65 g; P = .005) compared with controls (42.5 +/- 1.65 g). All other measures were significantly reduced (P < .05) except cerebellar and brain-stem weights. At term, whole-brain weight was also significantly reduced (42.4 +/- 1.52 g; P = .001) compared with controls (53.4 +/- 1.73 g) as were all other measures (P < .05).

CONCLUSION

Administration of single and repeated courses of corticosteroids to pregnant sheep retarded fetal brain growth.

Effect of exogenous corticosteroids on the developing central nervous system: a review

Corticosteroid therapy is used in a variety of developmental clinical settings. Prenatally, maternal administration of corticosteroids is used primarily in the prevention of respiratory distress syndrome. Postnatally, corticosteroids are used to treat a variety of infant diseases such as autoimmune hemolytic anemia and hypoglycemia. Treatment regimes often involve repeated administration, on a weekly basis prenatally and daily postnatally, despite an absence of safety data from randomized clinical trials. A large number of animal studies, the majority of which used rodents, have shown that both repeated prenatal or neonatal administration of exogenous corticosteroids has a wide range of detrimental effects on the structure and function of the developing central nervous system (CNS). None of these studies included long-term follow-up. Despite the reported detrimental effects on CNS development, a number of animal studies have shown that pretreatment with corticosteroids nevertheless protect the brain from hypoxia-ischemic injury; however, clinically such treatment is no longer favored. Studies using large animal models and with long-term follow-up should be undertaken to establish the relative risks and benefits of the repeated application of exogenous corticosteroids.

Reversal of tumor multidrug resistance by 2-phenyl-3-(3',5'-dimorpholinomethyl-4'-hydroxy)-benzoyl-indole (HWL-12)

AIM

To explore the reversal of multidrug resistance (MDR) by indole derivative HWL-12.

METHODS

Cytotoxicity was determined by tetrazolium (MTT) assay. The function of P-gp was examined by Fura 2-AM assay. Cellular accumulation of doxorubicin (Dox) was measured by fluorescence spectrophotometry.

RESULTS

HWL-12 10 mumol.L-1 markedly increased Fura-2 accumulation and was 17.2-fold reversal of MDR in MCF-7/ADR cells. The cellular Dox accumulation in MDR cells was increased in the presence of HWL-12 on the MCF-7/ADR cells. No effect was observed for Dox accumulation in the presence of high Ca2+ (addition of CaCl2) or low Ca2+ (addition of egtazic acid).

CONCLUSION

HWL-12 has a potent MDR reversal action which was associated with the increase of cellular Dox accumulation in MDR cells and not related with calcium ion concentration.

Improvement of hepatitis B virus DNA vaccines by plasmids coexpressing hepatitis B surface antigen and interleukin-2

DNA vaccines encoding a viral protein have been shown to induce antiviral immune responses and provide protection against subsequent viral challenge. In this study, we show that the efficacy of a DNA vaccine can be greatly improved by simultaneous expression of interleukin-2 (IL-2). Plasmid vectors encoding the major (S) or middle (pre-S2 plus S) envelope proteins of hepatitis B virus (HBV) were constructed and compared for their potential to induce hepatitis B surface antigen (HBsAg)-specific immune responses with a vector encoding the middle envelope and IL-2 fusion protein or with a bicistronic vector separately encoding the middle envelope protein and IL-2. Following transfection of cells in culture with these HBV plasmid vectors, we found that the encoded major protein was secreted while the middle protein and the fusion protein were retained on the cell membrane. Despite differences in localization of the encoded antigens, plasmids encoding the major or middle proteins gave similar antibody and T-cell proliferative responses in the vaccinated animals. The use of plasmids coexpressing IL-2 and the envelope protein in the fusion or nonfusion context resulted in enhanced humoral and cellular immune responses. In addition, the vaccine efficacy in terms of dosage used in immunization was increased at least 100-fold by coexpression of IL-2. We also found that DNA vaccines coexpressing IL-2 help overcome major histocompatibility complex-linked nonresponsiveness to HBsAg vaccination. The immune responses elicited by HBV DNA vaccines were also modulated by coexpression of IL-2. When restimulated with antigen in vitro, splenocytes from mice that received plasmids coexpressing IL-2 and the envelope protein produced much stronger T helper 1 (Th1)-like responses than did those from mice that had been given injections of plasmids encoding the envelope protein alone. Coexpression of IL-2 also increased the Th2-like responses, although the increment was much less significant.

Swyer-James syndrome associated with Noonan syndrome: report of a case

A 28-year-old man with Noonan syndrome associated with unilateral hyperlucent lung is reported. He had the typical craniofacial appearance and short stature of Noonan syndrome; he had mild mental retardation, atrophic testis, mild funnel chest and kyphosis. cardiovascular abnormalities included asymmetric hypertrophic cardiomyopathy and a significantly different caliber of the left and right pulmonary arteries. The unilateral hyperlucent lung was shown to result from acquired nondestructive emphysema caused by nonvalvular obstruction of the bronchi (Swyer-James syndrome or Macleod's syndrome). To the authors' knowledge, this is the first reported case of Noonan syndrome associated with Swyer-James syndrome.

A molecular study of ocular herpes simplex infection in Kaohsiung, Taiwan. Part I: Cleavage pattern analysis

In order to investigate the relationship between genotypes of herpes simplex virus (HSV) and its clinical pictures in herpes simplex virus keratoconjunctivitis (HSK), fifty nine strains of HSV isolates, collected in the Kaohsiung Medical College Hospital during January 1981 to July 1991, and F strain (ATCC VR-73), a standard HSV-1, were studied. The viruses were isolated from HSK patients. All 59 strains were identified as HSV-1 using immunofluorescence monoclonal antibody method. The HSV DNAs were extracted and digested by restriction enzymes, BamH I, Kpn I and Sal I, followed by electrophoresis, and photographing. Six kinds of DNA cleavage patterns were found in Taiwan. The majority were E subtype (56.4%) then A subtype (27.3%), D subtype (7.3%), F subtype (5.4%), G subtype (1.8%) and H subtype (1.8%). Subtypes B and C were not found in this study. The cleavage patterns of two recurrent cases belonged to E and A subtypes. The identical cleavage patterns of two bilateral infections all belonged to the E subtype.

Prominent proliferative response of peripheral blood mononuclear cells to a recombinant non-structural (NS3) protein of hepatitis C virus in patients with chronic hepatitis C

The proliferative response of peripheral blood mononuclear cells (PBMC) to a recombinant non-structural (NS3) protein of hepatitis C virus (HCV) was studied in 41 patients with chronic hepatitis C. Of them, 28 had chronic persistent hepatitis (CPH) and 13 chronic active hepatitis (CAH). The positive proliferation rate of PBMC to the recombinant NS3 protein, T9Ag, was 66% in the 41 patients (77% in CAH versus 61% in CPH; P > 0.05) when stimulation index (SI) = 4 was set as the cut-off value. However, mean SI of CAH patients was significantly higher than that of CPH patients (8.3 +/- 5.2 versus 5.1 +/- 3.6; P < 0.05). Six other chronic hepatitis patients who were repeatedly negative for anti-HCV antibody but positive for serum HCV RNA also had an SI of > or = 4.0. The frequency of cellular immune response to the T9Ag is among the highest results obtained by using HCV antigens tested so far. Our studies thus indicate that NS3 is an immunologically important region of HCV for T cells. Moreover, the proliferative response to T9Ag may help to establish hepatitis C etiology in chronic hepatitis patients who are seronegative with currently available anti-HCV assays.

[The re-evaluation of the prevalence of trachoma in primary school children in Kaohsiung City]

For years, trachoma screening has been a routine part of the health examination program for all primary school children. In order to ascertain the current prevalence of trachoma in primary school children, we used clinical examination, immunofluorescein-monoclonal antibody and McCoy cell culture technique to examine 771 children from 5 primary schools in Kaohsiung City. Using the results of the McCoy cell culture as a judgement standard, we found that 118 children (15.3%) had chlamydia trachomatis infections. The infection rates of children were statistically insignificant for sex, grade and location of school of children. Among the 118 infected children, most had none or mild (96.6%) conjunctival inflammation. Only 3 children (0.4%) had conjunctival cicatrization complications. These results showed that the repeated reinfections among these children were quite few. The McCoy cell culture was used to test the result of clinical diagnosis made by the senior ophthalmologists. The sensitivity of the clinical diagnosis was 50% and the predictive positive rate was 26.6%. It revealed that the diagnosis of trachoma made by clinical observation only was unreliable. The results of immunofluorescein-monoclonal antibody test showed that 120 children (15.6%) had trachomatous infections. Its sensitivity was 68.4%, and specificity was 91.7%. It revealed that more care should be taken in quality control of laboratory techniques. From these results, we conclude: 1) the trachomatous infections of primary school children in Kaohsiung City are not serious; the repeated infections among

Expression of the Epstein-Barr virus DNA polymerase in Escherichia coli for use as antigen for the diagnosis of nasopharyngeal carcinoma

Epstein-Barr virus (EBV) encoded DNA polymerase (POL) was cloned and over-expressed in Escherichia coli. Western blot analysis confirmed the presence of antibody to this POL protein in sera from nasopharyngeal carcinoma (NPC) patients. By Western blot analysis, moderate to high concentration of IgG POL-specific antibodies were present in 43 of 48 NPC sera and only 4 of 48 healthy, seropositive controls. The POL-specific IgG antibodies appear as early as stage I of NPC, suggesting that the recombinant POL protein can be a useful diagnostic marker for early diagnosis of the disease. It was also found that human sera containing high titer of cytomegalovirus (CMV) antibodies or herpes simplex virus type 1 (HSV-1) antibodies did not cross-react with the recombinant EBV POL, despite the homology shared by DNA polymerase proteins of these viruses.

Analysis of T-lymphocyte subpopulations in inflammatory bowel diseases by three-color flow cytometry

In order to better define changes in the relative proportion of peripheral blood T-lymphocyte subpopulations in patients with inflammatory diseases of the bowel, we performed simultaneous three-color fluorescence-activated cytometric (FACS) analysis using fluorophore-conjugated monoclonal antibodies with specificity for CD4, CD8, Leu 8, and CD45RA on 22 normal control subjects, 28 patients with Crohn's disease (CD), 15 patients with ulcerative colitis (UC), and 11 patients with intestinal inflammation secondary to etiologies other than inflammatory bowel disease (NIBD). This staining combination allowed enumeration of distinct T-cell subpopulations as follows: virgin CD4+, recall antigen helper T cells, nonspecific B-cell helper T cell, virgin CD8+, cytotoxic effector and suppressor effector and recall antigen cytotoxic T cells based on a synthesis of published functional analyses. No differences in the proportion of CD4+ or CD8+ cells or in the CD4+/CD8+ ratios were evident when UC and NIBD patients were compared to normal subjects. A significant reduction in the proportion of CD4+ cells and an increase in CD8+ cells was observed, however, in the CD group. When two-color analysis was performed, several significant differences in the proportions of circulating lymphocytes were seen. Specifically, these included significant increases in the number of CD4+, Leu 8- (P < 0.01) cells in all disease groups and an increase in CD4+, CD45RA+ cells in the NIBD group. Conversely, significant decreases in the proportions of CD8+, Leu 8+ (P < 0.01) cells were evident in the Crohn's disease group.(ABSTRACT TRUNCATED AT 250 WORDS)

Study on some biological and antigenic characteristics of CA24v isolates in Taiwan in 1985-1989

In order to understand the relationship between the CA24v isolates which caused two epidemics of acute hemorrhagic conjunctivitis (AHC) in 1985-1986 and 1988-1989 in Taiwan, biological and antigenic characteristics were studied with four CA24v strains, L077/85, V116/86, 590/88 and 722/89, which were isolated during the epidemics. The prototype strain, EH24/70, was used for comparison. In terms of cross neutralization, kinetic neutralization, plaque assay and protein electrophoresis, no obvious differences were found between the isolates from the two epidemics though differences were found between these isolates and the prototype.