[Arf6 regulates endometriotic epithelial-mesenchymal transition and mitochondrial distribution]

Objective: To investigate the role of adenosine diphosphate ribosylation factor 6 (Arf6) in the pathogenesis of endometriosis. Methods: Endometrial tissues were sampled from women who were hospitalized in the Affiliated Hospital of Medical School of Ningbo University and Ningbo Women and Children's Hospital from November 2020 to May 2021 with endometriosis (n=44, endometriosis group) and without endometriosis (n=17, control group). The expression of Arf6 protein in the endometrial tissues was detected by western blot. Endometrial epithelial cells from both groups were primary cultured and the distribution of intracellular mitochondria was detected by immunofluorescence. The expression of Arf6 protein was down-regulated by small interference RNA (siRNA), the distribution of mitochondria in cells with decreased Arf6 protein expression was observed, and the expression of mitochondria-related proteins development and differentiation enhancing factor 1 (DDEF1, also called AMAP1), reactive oxygen species 1 (ROS1) and epithelial-mesenchymal transition (EMT)-related proteins E-cadherin, vimentin were detected. Transwell assay was used to detect the changes in the migration ability of the cells. Results: Compared with the control group, ectopic endometrial tissue of endometriosis group showed high expression of Arf6 protein (0.174±0.019 vs 0.423±0.033; t=29.630, P<0.01); and in ectopic endometrial epithelial cells, mitochondria were distributed near the edge of the cell membrane. While Arf6 expression was down-regulated by siRNA, the distribution of mitochondria in ectopic cells returned to natural, close to the control level. In addition, the expression levels of AMAP1 and ROS1 in ectopic cells after Arf6 protein knockdown were significantly decreased. Transwell assay results indicated that knockdown of Arf6 could reduce the migration ability of ectopic epithelial cells [migration cell count: (34.3±7.5) cells]; and immunofluorescence verified low expression of E-cadherin but high expression of vimentin in ectopic epithelial cells, whereas knockdown of Arf6 protein E-cadherin expression increased but vimentin expression decreased. Conclusions: High expression of Arf6 protein in ectopic endometrial epithelial cells leads to the distribution of mitochondria tending to membrane marginalization, while inducing EMT, which are involved in the mechanism of endoheterosis pathogenesis.

[Development of a Ranking Tool for Scientificity, Transparency and Applicability of Clinical Practice Guidelines]

Objective: To address the limitations of existing methods and tools for evaluating clinical practice guidelines, we aimed to develop a comprehensive instrument focusing on the three main dimensions of guideline development: scientificity, transparency, applicability. We will use it to rank the guidelines according to the scores. We abbreviated it as STAR, and its reliability, validity and usability were also tested. Methods: A multidisciplinary expert working group was set up, including methodologists, statisticians, journal editors, medical professionals, and others. Scoping review, Delphi methods and hierarchical analysis were used to determine the final checklist of STAR. Results: The new instrument contained 11 domains and 39 items. Intrinsic reliability of each domain was indicated by Cronbach's α coefficient, with a average value of 0.646. The Cohen's kappa coefficients for methodological evaluators and clinical evaluators were 0.783 and 0.618. The overall content validity index was 0.905. The R2 for the criterion validity analysis was 0.76. The average score for usability of the items was 4.6, and the mean time spent to evaluate each guideline was 20 minutes. Conclusion: The instrument has good reliability, validity and evaluating efficiency, and can be used for evaluating and ranking guidelines more comprehensively.

[Establishment of nomogram predicting model for the death risk of extremely severe burn patients and the predictive value]

Objective: To explore the death risk factors of extremely severe burn patients, establish a death risk nomogram predicting model, and investigate the predictive value for death risk of extremely severe burn patients. Methods: The medical records of 231 extremely severe burn patients (190 males and 41 females, aged 18-60 years) who were admitted to the Institute of Burn Research of the First Affiliated Hospital of Army Medical University from January 2010 to October 2018 and met the inclusion criteria were analyzed retrospectively. According to the final outcome, the patients were divided into survival group of 173 patients and death group of 58 patients. The sex, age, severity of inhalation injury, total burn area, full-thickness burn area, burn index, rehydration coefficient and urine volume coefficient of the first and second 24 h after injury, the first base excess, shock index, and hematocrit (HCT) after admission, whether to have pre-hospital fluid infusion, use of ventilator, and use of continuous renal replacement therapy (CRRT), and abbreviated burn severity index (ABSI ) and Baux score on admission of patients in the two groups were recorded or calculated. According to the use of ventilator, the patients were divided into with ventilator group of 131 patients and without ventilator group of 100 patients, and the death, total burn surface area, burn index, incidence and severity of inhalation injury were recorded. According to the use of CRRT, the patients were divided into with CRRT group of 59 patients and without CRRT group of 172 patients, and the death, total burn surface area, and burn index were recorded. Data were statistically analyzed with t test, chi-square test, and Mann-Whitney U test to screen the death related factors of patients. The indexes with statistically significant differences between survival group and death group were included in the multivariate logistic regression analysis to screen the independent death risk factors of patients, and the death risk nomogram predicting model was constructed based on the results.The Bootstrap method was used to validate the death risk nomogram predicting model internally. The predictive value of the nomogram model for predicting death risk of patients was detected by drawing calibration graph and calculating concordance index, and the death risk scores of 231 patients were acquired according to the death risk nomogram model. The receiver's operating characteristic (ROC) curve was drawn, and the optimal threshold and the sensitivity and specificity of optimal threshold in the ROC curve and the area under the curve were calculated. Results: (1) There were statistically significant differences in burn index, ABSI on admission, severity of inhalation injury, total burn area, full-thickness burn area, rehydration coefficient at the first 24 h after injury, use of ventilator, use of CRRT, and Baux score on admission of patients between the two groups (Z=-7.696, -7.031, χ(2)=18.304, 63.065, 23.300, 13.073, 34.240, 59.586, t=-7.536, P<0.01). (2) There were statistically significant differences in death, incidence and severity of inhalation injury, total burn area, and burn index of patients between with ventilator group and without ventilator group (χ(2)=34.240, 17.394, 25.479, Z=-6.557, -7.049, P<0.01). (3) There were statistically significant differences in death, total burn area, and burn index of patients between with CRRT group and without CRRT group (χ(2)=62.982, Z= -47.421, -6.678, P<0.01). (4) The use of ventilator, use of CRRT, and burn index were independent risk factors for the death of extremely severe burn patients (odds ratio=3.277, 5.587, 1.067, 95% confidence interval=1.073-10.008, 2.384-13.093, 1.038-1.096, P<0.05 or P<0.01). (5) The initial concordance index of nomogram predicting model was 0.90 and the corrected concordance index was 0.89. The concordance indexes before and after correction were higher and similar, which showed that the nomogram had good concordance and predictive effect. The optimum threshold of ROC curve was 0.23, the sensitivity and specificity of optimum threshold were 86.0% and 80.0%, respectively, and the area under ROC curve was 0.90 (95% confidence interval=0.86-0.94, P<0.01). Conclusions: Severe burns and damage and/or failure of organ are the main death causes of extremely severe burn patients. The death risk nomogram predicting model established on the basis of use of ventilator, use of CRRT, and burn index have good predictive ability for death of extremely severe burn patients.

Notch signaling is involved in regulation of LPS-induced macrophage apoptosis through JNK/NF-kB signaling pathway

Notch signaling plays a critical role in the development and function of macrophages. The aim of the present study was to investigate the relationship between Notch signaling pathway and macrophage apoptosis after LPS stimulation. In RAW 264.7 cells, the mRNA expression of Jagged1, Hes1, Hes 5 and GM-CSF, and protein expression of NICD1 and GM-CSF were increased after LPS stimulation. Inhibition of Notch signaling by γ-secretase inhibitor DAPT and the suppression of Notch1 expression using siRNA both significantly prevented LPS induced activation of JNK and NF-kB, and simultaneously the expression of GM-CSF was also down regulated significantly. JNK inhibitor SP600125 was used to block the phosphorylation of JNK signaling, Western blot results showed that the activation of NF-kB was blocked and expression of GM-CSF was down-regulated. Finally, flow cytometry analyses showed that the Notch signaling was involved in the regulation of macrophage apoptosis after LPS stimulation. Our study showed that the Notch signaling pathway was activated and involved in the regulation of macrophage apoptosis after LPS stimulation through JNK/ NF-kB signaling regulated GM-CSF expression.

[Anemia status of Chinese rural women of reproductive age in 2012]

Objective: To study the hemoglobin concentration, anemia status and its determinant factors among Chinese rural women of reproductive age in 2012. Methods: This was a cross-sectional study. The data was obtained from the National Free Preconception Health Examination Project (NFPHEP). A total of 712 101 Chinese rural reproductive age women aged 21-49 years old who came from 193 counties of 30 provinces were included. The demographic characteristics were obtained from questionnaires. Hemoglobin concentration was measured using the cyanomethemoglobin method. The definition of anemia we used was recommended by World Health Organization, and was adjusted according to altitude level. The hemoglobin concentration level, the prevalence of anemia and its 95% CI was calculated. Determinant factors of anemia such as demographic characteristics and histories of pregnancy and miscarriage were analyzed using logistic regression. Results: In 2012, the level of hemoglobin concentration in Chinese rural women of reproductive age was (127.77±13.47) g/L, with the lowest in 21-24 years group, which was (127.54±13.54) g/L, and highest in 35-39 years group, which was (128.39±14.12) g/L. In terms of region, the hemoglobin concentration level was lowest in central south, which was (125.79±12.00) g/L, and highest in southwest, which was (129.91±14.37) g/L. The prevalence of anemia in Chinese rural women of reproductive age was 24.80%, with the highest seen in 21-24 years, which was 25.92% (95% CI: 25.74%-26.11%), and lowest in 30-34 years, which was 23.61% (95% CI: 23.37%-23.85%). The prevalence in northwest (28.31%, 95% CI: 28.01%-28.61%) was the highest among all regions, and the prevalence in east (20.88%, 95% CI: 20.68%-21.09%) was the lowest. Conclusions: The prevalence of anemia in Chinese rural reproductive age women was 24.80% in 2012. The anemia prevalence was higher among women who were young, had low educational level, and lived in northwest region.

[Advances in the research of application of urine output monitoring in prevention and treatment of burn shock]

Fluid therapy is a crucial treatment for patients with extensive burn, which affects patients'prognosis directly. Accurate urine output measurement plays an irreplaceable role in guiding fluid resuscitation in clinic. As one of the best indexes in traditional burn resuscitation, urine output comprehensively reflects systemic circulation. However, it doesn't fully reflect all the specific chapters of microcirculation and systemic circulation and deficient cellular oxygen metabolism exactly. We need to use urine output combined with other shock parameters to ensure adequate fluid replacement. Currently, the most common way of urine output monitoring is manual measurement. The article reviews the application of urine output monitoring in guiding fluid resuscitation of burn shock.

[Advances on epidemiological research of human infections with novel avian influenza A (H7N9) virus]

Human infections with novel avian influenza A(H7N9)virus was an emerging infectious disease discovered in March, 2013. As of June30, 2016, 770 cases of H7N9 were reported in worldwide including 315 deaths with 40.9% of high case fatality rate. Yangtze River Delta and Pearl River Delta were the high-prevalence area. Formerly, the cases of H7N9 were concentrated on the municipalities. However, most of the case-patients were from smaller cities or rural areas nowadays. The H7N9 human infections mainly occurred in winter and spring every waves as similar as seasonal and H5N1 human infections. Middle aged and old (the median age was 61 years) male patients were occupied the large proportion among the cases of H7N9. In addition, the phenomenon of the limited and unsustained human-to-human transmission were existed. At present, the 4 major epidemic waves had happened and human infections with novel avian influenza A (H7N9) virus could be outbreak regularly in China. In this paper, the pathogenic characteristics and disease distribution of H7N9 influenza A viruses were elaborated, with both transmission factors and control measures, which were helpful to provide the scientific evidence for prevention and control in H7N9avian influenza epidemic.

Efficacy and safety of fosaprepitant in the prevention of nausea and vomiting following highly emetogenic chemotherapy in Chinese people: A randomized, double-blind, phase III study

The prevention of chemotherapy‐induced nausea and vomiting was one of the most challenging supportive care issues in oncology, especially to highly emetogenic chemotherapy (HEC). A total of 645 patients were randomized into fosaprepitant group (fosaprepitant/placebo 150 mg d1 in combination with granisetron and dexamethasone) or aprepitant group (aprepitant/placebo 125 mg d1; 80 mg d2‐d3 plus granisetron and dexamethasone).The primary endpoint was the percentage of patients who had a complete response (CR) over the entire treatment course (0–120 hr, overall phase [OP]). It was assessed by using a non‐inferiority model, with a non‐inferiority margin of 10%. The difference of the CR rate was compared between two groups with chi‐square analysis. Six hundred and twenty‐six patients were included in the per protocol analysis. The percentage of patients with a CR in the fosaprepitant group was not inferior to that in the aprepitant group (90.85% versus 94.17%, p = .1302) during OP. Whether the cisplatin‐based chemotherapy or not, the CR rate of the fosaprepitant group was not inferior to that of the aprepitant group. Both regimens were well tolerated. The most common adverse event was constipation. Fosaprepitant provided effective and well‐tolerated control of nausea and vomiting associated with HEC in Chinese patients.

[Investigation on folic acid supplementation status among Chinese women in the first trimester of pregnancy]

OBJECTIVE

To investigate folic acid (FA) supplementation status among Chinese rural reproductive women in their early pregnancy, and to provide evidence for the evaluation of FA supplementation project from national basic public health services.

METHODS

The data on intake status of FA supplementation from "National Free Preconception Health Examination Project (NFPHEP)" database between January 1, 2010 and December 31, 2012 was used and analyzed.A total of 902 270 women who achieved follow-up during early pregnancy from 220 pilot counties of 31 provinces were recruited.

RESULTS

From 2010 to 2012, the rate of FA intake among women recuited were 73.58% (134 131/182 289), 75.88% (329 288/433 970) and 76.53% (218 896/286 011), respectively, which increased year by year (χtrend(2)=13 371.8, P<0.001). Among 682 315 women who took FA, 350 738(51.40%) women began to take FA 3 months before amenorrhea; 130 683 (19.15%) women began to take FA 1-2 months before amenorrhea, and 200 894 (29.44%) began to take FA after amenorrhea.Among 682 315 women who took FA, 645 310 (94.58%) women took it regularly, and 342 418 (50.18%) women took FA in a standardized way.

CONCLUSIONS

The status of FA intake among Chinese rural women in the first trimester of pregnancy was good, and 75.62% (682 315/902 270) of them took FA.It is also important for basic public health services to improve the rate of FA intake and increase the rate of taking FA in a standardized way in Chinese rural pregnant women.

[Finite element analysis of astigmatic keratotomy based on corneal biomechanical properties]

OBJECTIVE

To establish a finite-element biomechanical model of astigmatic keratotomy, and to investigate the impact of surgical parameters on corneal deformation, stress distribution and astigmatism correction.

METHODS

With Rhinoceros modeling and Abaqus finite element analysis software, a three-dimensional finite-element model of astigmatic cornea was developed, and surgical parameters such as incision optical zone, incision depth and length were varied. Postoperative corneal stress, apical deformation and astigmatism correction were assessed.

RESULTS

A significant increase of stress was noticed near corneal incisions, and maximum corneal stress decreased with the increase of incision depth. Both anterior and posterior corneal surface moved slightly forward postoperatively. Maximum corneal stress was 340 392, 361 022 and 214 187 Pa, and anterior and posterior apical deformation was 49.80, 51.64, 55.53 μm and 54.15, 55.91, 59.67 μm, with 45°, 60° and 90° in arc length of the incision, respectively. The refractive power decreased in steep meridian and increased in flat meridian, resulting in a total decrease of corneal astigmatism. The magnitude of astigmatism correction was 0.85, 1.59, 2.23 and 3.06 D with 30°, 45°, 60° and 90° in arc length of the incision, respectively.

CONCLUSIONS

The finite-element biomechanical model of astigmatic keratotomy could be used to predict the optical outcomes after surgery. The magnitude of astigmatism correction is positively correlated with the surgical incision arc length. (Chin J Ophthalmol, 2016, 52: 674-680).

[Clinical results of transepithelial corneal collagen cross-linking in the treatment of keratoconus]

OBJECTIVE

To evaluate the effect of transepithelial corneal collagen cross-linking (CXL) in the treatment of keratoconus.

METHODS

Prospective study. Sixteen eyes of 16 patients with keratoconus underwent transepithelial CXL, and the fellow eyes were considered as the controls. The mean age was (22.4±6.5) years old. In the CXL group, topical anesthesia (0.1% tetracaine) was given for 15 minutes, and 0.5% riboflavin was applied until saturated in the anterior chamber. Then an ultraviolet A irradiance of 3 mW/cm(2) on the cornea was performed for 30 minutes. Postoperative corneal reepithelization time was recorded. Preoperative and postoperative examinations included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error, topography, corneal biomechanical parameters, thinnest corneal thickness, and endothelial cell density.

RESULTS

The mean corneal reepithelization time was 1.0(1.0 to 2.0) days. In the transepithelial CXL group, at the end of the 12-month follow-up, CDVA and refractive outcomes were significantly improved (P<0.05). Maximum K-value, anterior and posterior elevations were significantly decreased by (-2.23 ± 2.82)D (t=-3.153, P=0.007), (-4.69 ± 4.99) μm (t=-3.758, P=0.002), and (-13.94 ± 25.81) μm (t=-2.160, P=0.047), respectively. Corneal hysteresis, corneal resistance factor, thinnest corneal thickness, and endothelial cell density showed no significant difference (P>0.05). The differences in the changes of UDVA, CDVA, spherical equivalent refraction, and maximum K-value between the CXL and control groups were significant at 12 months (P<0.05).

CONCLUSION

Transepithelial CXL is effective in optimizing the irregular corneal surface of keratoconus, and might halt its progression. (Chin J Ophthalmol, 2016, 52: 525-530).

Development of a Continuous Fluorescence Assay for Rhinovirus 14 3C Protease Using Synthetic Peptides

Rhinovirus 3C protease is an attractive target for therapeutic intervention owing to its important role in virion maturation and infectivity. In order to facilitate the identification of potential 3C protease inhibitors, we have developed a continuous fluorescence assay using 5-[(2-aminoethyl)amino]naphthalene-1-sulphonic acid (Edans) as a fluorescent donor and 4-(4-dimethylaminophenylazo)benzoic acid (Dabcyl) as a quenching acceptor. Several fluorogenic peptide substrates for 3C protease were synthesized by both solution chemistry and solid phase peptide synthesis. One of the synthetic Edans/Dabcyl substrates, with an amino acid sequence derived from the 2C/3A site of the virus polyprotein, yielded a 24-fold increase in fluorescence intensity after 3C cleavage. Data regarding substrate cleavage kinetics, assay sensitivity and optimization are presented. The application of this assay to the evaluation of 3C protease inhibitors is also shown.

Sevoflurane induces neurotoxicity in young mice through FAS/FASL signaling

Sevoflurane, the most widely used anesthetic in clinical practice, has been shown to induce apoptosis, inhibit neurogenesis, and cause learning and memory impairment in young mice. However, the underlying mechanism is still unknown. In this study, wild-type and the FAS- or FAS ligand (FASL)-knockout mice (age 7 days) were exposed to sevoflurane or pure oxygen. Western blotting was used to examine the expression of FAS protein. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) and bromodeoxyuridine (BrdU) staining were employed to quantify the apoptotic cells and newborn cells in the hippocampus and Morris water maze (MWM) in order to evaluate learning and memory status. Sevoflurane significantly increased the expression of FAS protein in wild-type mice. Compared to FAS- and FASL-knockout mice treated with sevoflurane, sevoflurane-treated wild-type mice exhibited more TUNEL-positive hippocampal cells and less BrdU-positive hippocampal cells. The MWM showed that compared with FAS- and FASL-knockout mice treated with sevoflurane, sevoflurane treatment of wild-type mice significantly prolonged the escape latency and reduced platform crossing times. These data suggest that sevoflurane induces neurotoxicity in young mice through FAS-FASL signaling.

Tunable dielectric properties of ferrite-dielectric based metamaterial

A ferrite-dielectric metamaterial composed of dielectric and ferrite cuboids has been investigated by experiments and simulations. By interacting with the electromagnetic wave, the Mie resonance can take place in the dielectric cuboids and the ferromagnetic precession will appear in the ferrite cuboids. The magnetic field distributions show the electric Mie resonance of the dielectric cuboids can be influenced by the ferromagnetic precession of ferrite cuboids when a certain magnetic field is applied. The effective permittivity of the metamaterial can be tuned by modifying the applied magnetic field. A good agreement between experimental and simulated results is demonstrated, which confirms that these metamaterials can be used for tunable microwave devices.

Identification and functional analysis of differentially expressed genes related to obesity using DNA microarray

We looked for differentially expressed genes at different stages of preadipocyte differentiation and examined their functions, based on DNA microarrays of preadipocytes obtained from healthy subjects undergoing cosmetic liposuction. We downloaded gene expression profile GSE25910 from the Gene Expression Omnibus database and identified the differentially expressed genes with packages in R language. The selected differentially expressed genes were further analyzed using bioinformatics methods. Comparing gene expression at different stages of preadipocytes differentiation, we found that expression of 668 and 1007 genes were altered in middle and late stages compared with the early stage, respectively. Function analysis revealed that the differentially expressed genes were mainly related to fatty acid metabolic processes in the former two stages.

Oxidation behaviour of Ti2AIN films composed mainly of nanolaminated MAX phase

In this paper, we reported the oxidation behaviour of Ti2AIN films on polycrystalline Al2O3 substrates. The Ti2AIN films composed mainly of nanolaminated MAX phase was obtained by first depositing Ti-Al-N films using reactive sputtering of two elemental Ti and Al targets in Ar/N2 atmosphere and subsequent vacuum annealing at 800 degrees C for 1 h. The Ti2AIN films exhibited excellent oxidation resistance and thermal stability at 600-900 degrees C in air. Very low mass gain was observed. At low temperature (600 degrees C), no oxide crystals were observed on film surface. Blade-like Theta-Al2O3 fine crystals formed on film surfaces at 700-800 degrees C. At high temperature (900 degrees C), firstly Theta-Al2O3 formed on film surface and then transformed into alpha-Al2O3. At 700-900 degrees C, a continuous Al2O3 layer formed on Ti2AIN films surface, acting as diffusion barrier preventing further oxidation attack. The mechanism of the excellent oxidation resistance of Ti2AIN films was discussed based on the experimental results.

[Effect of daphnetin on the exo-erythrocytic stage of rodent malaria]

OBJECTIVE

To investigate the activity of daphnetin(DPNT) against the exo-erythrocytic stage of rodent malaria.

METHODS

Groups of ten male ICR mice were infected by intraperitoneal injection with sporozoites of P. yoelii. Mice were administered daphnetin 0.5 hr postinfection on d0 and once per day for three additional consecutive days(d1-d3) by the i.g. route. The effects of daphnetin at various dosages and those of the combination of daphnetin with primaquine were assessed by the number of mice with negative Giemsa-stained slides from tail blood on the seventh day after infection and by the average number of red blood cells (RBC) infected in 1,000 RBC observed on the eleventh or twelfth day after infection. We also observed the effect of daphnetin on the concentration of Hb in ICR mice.

RESULTS

Daphnetin exhibited no detectable antimalarial effect on the exo-erythrocytic stage of P. yoelii, while the antimalarial efficacy of DPNT 50 mg/(kg.d) combined with 5 mg/(kg.d) PQ, was comparable to PQ 10 mg/(kg.d) x 4 d i.g. in mice infected with sporozoites of P. yoelii. The concentration of Hb in ICR mice administered with DPNT 50 mg/(kg.d) x 4 d decreased on the eighth day after administration.

CONCLUSION

Daphnetin alone showed no anti-exoerythrocytic activity in vivo. The combination of DPNT 50 mg/(kg.d) with PQ 5 mg/(kg.d) showed promising antimalarial efficacy comparable to that of PQ 10 mg/(kg.d). Administration of DPNT caused anemia in ICR mice.

[Immunostimulatory activity elicited by CpG sequences in Cysticercus cellulosae paramyosin cDNA]

OBJECTIVE

To analyse the immunostimulatory activity of CpG sequences in cysticercus cellulosae paramyosin (also named Antigen B, AgB) cDNA.

METHODS

C57BL/6 mice were immunized with pcDNA3-AgB plasmid, pcDNA3-AgB' (CpG sequences were mutated), pcDNA3 or AgB protein and two weeks later, immune response was assayed by ELISA.

RESULTS

IgG and IgG2a were detectable at week 2 after immunization and continually increased until week 4. The antibody levels elicited by pcDNA3-AgB were significantly higher(P < 0.05) than those elicited by others.

CONCLUSION

After pcDNA3-AgB plasmid inoculation, the immune response of mouse was elicited not only by the AgB protein but also by the CpG immunostimulatory sequences in the AgB cDNA.

The schizontocidal activity of daphnetin against malaria parasites in vitro and in vivo

OBJECTIVE

To investigate the in vitro and in vivo schizontocidal activity of daphnetin.

METHODS

Schizontocidal activity of daphnetin was tested using an in vitro assay based on the routine in vitro cultivation of P. falciparum FCC1 strain. The in vivo antimalarial effects of daphnetin at various dosages were assessed in mice infected with P. b. erghei ANKA according to "4-day suppress assay".

RESULTS

In vitro, daphnetin exhibited potent schizontocidal activity comparable to chloroquine(CQ) at the dose range of 1-10 mumol/L. In vivo, 50 or 100 mg/kg.d-1 x 4 d daphnetin i.g. and 10, 50 or 100 mg/kg.d-1 x 4 d dephnetin i.p. showed antimalarial efficacy comparable to CQ 10 mg/kg.d-1 x 4 d i.g. in mice infected with P. berghei ANKA, evaluated by both the reduction rate of parasitemia on D4 and the average surviving days in 30 days.

CONCLUSION

Daphnetin displays certain schizontocidal activity both in vitro and in vivo.

[Cloning of Cysticercus cellulosae AgB cDNA coding region]

OBJECTIVE

To amplify and clone Cysticercus cellulosae AgB cDNA coding region.

METHODS

The AgB cDNA was amplified by RT-PCR technique from the total RNA of Cysticercus cellulosae. It was cloned into the vector pUC118 and sequenced.

RESULTS

The PCR amplified product was a single band of 2.6 kb in size. The sequences of AgB cDNA coding region has 99.8% homology with that of Australian Cysticercus cellulosae, and their amino acid sequences have 99.3% homology.

CONCLUSION

Cysticercus cellulosae AgB cDNA coding region has been cloned successfully.

RNA-dependent RNA polymerase encoded by hepatitis C virus: biomedical applications

The hepatitis C viruses (HCVs) are a group of small enveloped RNA viruses that have been viewed as a leading cause of chronic hepatitis in humans. Infections by HCV represent a serious global health problem, because millions of people worldwide are infected and no efficient treatment is available at the present time. Since HCV was identified in 1989, considerable effort has been devoted to the discovery and development of novel molecules to treat HCV-related diseases. One of the approaches is the development of novel inhibitors that interrupt the normal functions of HCV NS5B, an RNA-dependent RNA polymerase essential to HCV replication. This review summarizes recent advances in the biochemical and structural understanding of HCV NS5B polymerase as well as in the development of antiviral agents targeting this important enzyme.

Recent advances in prevention and treatment of hepatitis C virus infections

Hepatitis C virus (HCV) is the leading cause of chronic hepatitis in humans. As members of the flavivirus family, HCVs are a group of small single-stranded, positive-sense RNA viruses. Upon translation of the genome, a polyprotein precursor is synthesized and further processed by both cellular and viral proteases to generate functional viral proteins. Treatment options are currently limited to the administration of alpha-interferon alone or in combination with ribavirin. Unfortunately, these approaches are characterized by relatively poor efficacy and an unfavorable side-effect profile. Therefore, intensive effort is directed at the discovery of novel molecules to treat this disease. These new approaches include the development of prophylactic and therapeutic vaccines, the identification of interferons with improved pharmacokinetic characteristics, and the discovery of novel drugs designed to inhibit the function of three major viral proteins: protease, helicase and polymerase. Finally, the HCV RNA genome itself, particularly the IRES element, is being actively exploited as an antiviral target using antisense molecules and catalytic ribozymes. This review summarizes the most recent findings in each of these areas. Although not intended to be comprehensive, it should serve as a first resource for those individuals who desire updated information in this rapidly changing field.

A novel luminescent copper(I) complex containing an acetylenediide-bridged, butterfly-shaped tetranuclear core

A novel luminescent acetylenediide-bridged tetranuclear copper(I) complex [Cu4(mu-Ph2Ppypz)4(mu 4-eta 1,eta 2-C identical to C)]-(ClO4)2 [Ph2Ppypz = 2-(diphenylphosphino-6-pyrazol-1-yl)pyridine] has been synthesized and structurally characterized by X-ray crystallography.

Argentophilicity and solvent-induced structural diversity in double salts of silver acetylide with silver perfluoroalkyl carboxylates

A series of novel double salts of silver(I) were isolated by dissolving Ag(2)C(2) in a concentrated aqueous solution of R(F)CO(2)Ag (R(F) = CF(3), C(2)F(5)) and AgBF(4). Different ancillary solvento ligands such as H(2)O, CH(3)CN, and C(2)H(5)CN were found to affect the crystallization process that led to the assembly of various silver(I) cages with embedded C(2)(2-) ions. 2Ag(2)C(2) x 12CF(3)CO(2)Ag x 5H(2)O (1) consists of two independent C(2)@Ag(7) cages, each having the shape of a basket with a square base. Ag(2)C(2) x 6CF(3)CO(2)Ag x 3CH(3)CN (2) contains a zigzag chain of edge-sharing triangulated dodecahedra, and 4Ag(2)C(2) x 23CF(3)CO(2)Ag x 7C(2)H(5)CN x 2.5H(2)O (3) features an unusual double-walled silver column constructed from the fusion of four different kinds of irregular polyhedra. Ag(2)C(2) x 10C(2)F(5)CO(2)Ag x 9.5H(2)O (4), Ag(2)C(2) x 9C(2)F(5)CO(2)Ag x 3CH(3)CN x H(2)O (5), and Ag(2)C(2) x 6C(2)F(5)CO(2)Ag x 2C(2)H(5)CN (6) all contain an edge-sharing double cage with each single cage in the shape of a square antiprism, a capped square antiprism, and a triangulated dodecahedron, respectively.

Identification and characterization of a monofunctional glycosyltransferase from Staphylococcus aureus

A gene (mgt) encoding a monofunctional glycosyltransferase (MGT) from Staphylococcus aureus has been identified. This first reported gram-positive MGT shared significant homology with several MGTs from gram-negative bacteria and the N-terminal glycosyltransferase domain of class A high-molecular-mass penicillin-binding proteins from different species. S. aureus MGT contained an N-terminal hydrophobic domain perhaps involved with membrane association. It was expressed in Escherichia coli cells as a truncated protein lacking the hydrophobic domain and purified to homogeneity. Analysis by circular dichroism revealed that secondary structural elements of purified truncated S. aureus MGT were consistent with predicted structural elements, indicating that the protein might exhibit the expected folding. In addition, purified S. aureus MGT catalyzed incorporation of UDP-N-acetylglucosamine into peptidoglycan, proving that it was enzymatically active. MGT activity was inhibited by moenomycin A, and the reaction product was sensitive to lysozyme treatment. Moreover, a protein matching the calculated molecular weight of S. aureus MGT was identified from an S. aureus cell lysate using antibodies developed against purified MGT. Taken together, our results suggest that this enzyme is natively present in S. aureus cells and that it may play a role in bacterial cell wall biosynthesis.

Recent advances in prevention and treatment of hepatitis C virus infections

Hepatitis C virus (HCV) is the leading cause of chronic hepatitis in humans. As members of the flavivirus family, HCVs are a group of small single-stranded, positive-sense RNA viruses. Upon translation of the genome, a polyprotein precursor is synthesized and further processed by both cellular and viral proteases to generate functional viral proteins. Treatment options are currently limited to the administration of alpha-interferon alone or in combination with ribavirin. Unfortunately, these approaches are characterized by relatively poor efficacy and an unfavorable side-effect profile. Therefore, intensive effort is directed at the discovery of novel molecules to treat this disease. These new approaches include the development of prophylactic and therapeutic vaccines, the identification of interferons with improved pharmacokinetic characteristics, and the discovery of novel drugs designed to inhibit the function of three major viral proteins: protease, helicase and polymerase. Finally, the HCV RNA genome itself, particularly the IRES element, is being actively exploited as an antiviral target using antisense molecules and catalytic ribozymes. This review summarizes the most recent findings in each of these areas. Although not intended to be comprehensive, it should serve as a first resource for those individuals who desire updated information in this rapidly changing field.

Activation of human rhinovirus-14 3C protease

The catalytic efficiency of human rhinovirus-14 (HRV14) 3C protease as a function of solvents and other regulators has been investigated using synthetic peptides as substrates. The proteolytic activity of HRV14 3C was found to be strongly stimulated by a series of anions in vitro and the activation was accompanied by changed Km, kcat, and increased kcat/Km values. A more than 72-fold increase in the 3C catalytic efficiency toward peptide substrates was observed in the presence of 0.8 M sodium sulfate. Several approaches, including size-exclusion chromatography and chemical cross-linking experiments, suggested that no oligomerization of the 3C enzyme occurred in the presence of activating anions. However, the anions did induce a significant conformational change of HRV14 3C protease, as revealed by circular dichroism spectrometry and tyrosine fluorescence analyses, which might contribute to 3C enzyme activation. Finally, the results obtained from 3C protease inhibitor studies suggested that the S1 specificity pocket of HRV14 3C was mainly affected by the activating anions. An induced-fit catalysis mechanism for viral proteases is discussed.

[Augmenter of liver regeneration: a novel cytokine]

Augmenter of liver regeneration (ALR) is a novel cytokine which specifically stimulates hepatic cell proliferation and is able to rescue acute liver failure caused by carbon tetrachloride. This article reviews the discovery, tissue distribution, functions and prospect of ALR and its relationship with hepatic stimulatory substance (HSS).

Protease inhibitors as potential antiviral agents for the treatment of picornaviral infections

The picornavirus family contains several human pathogens including human rhinovirus (HRV) and hepatitis A virus (HAV). In the case of HRVs, these small single-stranded positive-sense RNA viruses translate their genetic information into a polyprotein precursor which is further processed mainly by two viral proteases designated 2A and 3C. The 2A protease (2Apro) makes the first cleavage between the structural and non-structural proteins, while 3C protease (3Cpro) catalyzes most of the remaining internal cleavages. It has been shown that both 2Apro and 3Cpro are cysteine proteases but their overall protein folding is more like trypsin-type serine proteases. Due to their unique protein structure and essential roles in viral replication, 2Apro and 3Cpro have been viewed as excellent targets for antiviral intervention. In recent years, considerable efforts have been made in the development of antiviral compounds targeting these proteases. This article summarizes the recent approaches in the design of novel 2A and 3C protease inhibitors as potential antiviral agents for the treatment of picornaviral infections.

Biochemical characterization of signal peptidase I from gram-positive Streptococcus pneumoniae

Bacterial signal peptidase I is responsible for proteolytic processing of the precursors of secreted proteins. The enzymes from gram-negative and -positive bacteria are different in structure and specificity. In this study, we have cloned, expressed, and purified the signal peptidase I of gram-positive Streptococcus pneumoniae. The precursor of streptokinase, an extracellular protein produced in pathogenic streptococci, was identified as a substrate of S. pneumoniae signal peptidase I. Phospholipids were found to stimulate the enzymatic activity. Mutagenetic analysis demonstrated that residues serine 38 and lysine 76 of S. pneumoniae signal peptidase I are critical for enzyme activity and involved in the active site to form a serine-lysine catalytic dyad, which is similar to LexA-like proteases and Escherichia coli signal peptidase I. Similar to LexA-like proteases, S. pneumoniae signal peptidase I catalyzes an intermolecular self-cleavage in vitro, and an internal cleavage site has been identified between glycine 36 and histidine 37. Sequence analysis revealed that the signal peptidase I and LexA-like proteases show sequence homology around the active sites and some common properties around the self-cleavage sites. All these data suggest that signal peptidase I and LexA-like proteases are closely related and belong to a novel class of serine proteases.

Template requirements for RNA synthesis by a recombinant hepatitis C virus RNA-dependent RNA polymerase

The RNA-dependent RNA polymerase (RdRp) from hepatitis C virus (HCV), nonstructural protein 5B (NS5B), has recently been shown to direct de novo initiation using a number of complex RNA templates. In this study, we analyzed the features in simple RNA templates that are required to direct de novo initiation of RNA synthesis by HCV NS5B. NS5B was found to protect RNA fragments of 8 to 10 nucleotides (nt) from RNase digestion. However, NS5B could not direct RNA synthesis unless the template contained a stable secondary structure and a single-stranded sequence that contained at least one 3' cytidylate. The structure of a 25-nt template, named SLD3, was determined by nuclear magnetic resonance spectroscopy to contain an 8-bp stem and a 6-nt single-stranded sequence. Systematic analysis of changes in SLD3 revealed which features in the stem, loop, and 3' single-stranded sequence were required for efficient RNA synthesis. Also, chimeric molecules composed of DNA and RNA demonstrated that a DNA molecule containing a 3'-terminal ribocytidylate was able to direct RNA synthesis as efficiently as a sequence composed entirely of RNA. These results define the template sequence and structure sufficient to direct the de novo initiation of RNA synthesis by HCV RdRp.

S-nitrosothiols as novel, reversible inhibitors of human rhinovirus 3C protease

Human rhinovirus (HRV) 3C protease was inactivated by a series of S-nitrosothiols. These compounds exhibited different inhibitory activities in a time- and concentration-dependent manner with second-order rate constants (kinact/K(I)) ranging from 131 to 5360 M(-1) min(-1). The inactive enzyme could be re-activated by DTT, GSH and ascorbate, which indicated the inactivation mechanism was through an S-transnitrosylation process.

Changes in E2F binding after phenylbutyrate-induced differentiation of Caco-2 colon cancer cells

Differentiation agents use existing cellular systems to induce neoplastic cells to regain a normal phenotype and/or to cause growth arrest and therefore may offer novel chemotherapeutic approaches to treating solid tumors. In this study, we demonstrate in Caco-2 colon cancer cells that the differentiation agent phenylbutyrate (PB) causes a decrease in viable cells, an increase in cell differentiation, and a G1-S-phase block. The mechanism of this last effect is related to a PB-induced increase in p27Kip1, leading to a decrease in the activity of cyclin-dependent kinase 2 (CDK2), a positive regulator of the G1-S-phase cell cycle transition. Consistent with the decreased CDK2 kinase activity, we also observed a decrease in the phosphorylation state of the retinoblastoma protein after PB treatment. This was associated with increased binding and consequent inactivation of E2F, a transactivator of genes that regulate the G1 to S phase cell cycle transition. These data suggest that the differentiation agent PB inhibits tumor growth by limiting the availability of active E2F, with a subsequent G1-S-phase block. Additional studies should show whether PB is a clinically effective therapeutic agent against colorectal cancer.

Specificity and mechanism analysis of hepatitis C virus RNA-dependent RNA polymerase

The RNA-dependent RNA polymerase encoded by the hepatitis C virus (HCV) NS5B gene has been expressed as a nonfusion protein in bacterial cells and purified to homogeneity using sequential chromatographic columns. The purified NS5B protein exhibited RNA-dependent RNA polymerase activity using poly(A) template and the K(m) and V(max) were determined as 8.4 microM and 1976 pmol/mg-min, respectively. This full-length NS5B protein exhibited much stronger binding affinity toward the 30-mer poly(G) than other homopolymeric RNAs of the same size. For the first time, we demonstrate that the HCV NS5B was able to bind various ribonucleotides. Using a panel of oligonucleotides varying in length, we studied the NS5B catalytic efficiency and proposed the size of the NS5B active site to be 8-10 nucleotides. The multifunctional nature of NS5B protein is also discussed and compared with other viral RNA polymerases.

[An experimental study on inhibitory effect of xinjierkang granules on virus myocarditis]

OBJECTIVE

To investigate the inhibitory effect of Xinjierkang(XJEK) granules on virus myocarditis.

METHODS

Using a model mouse of virus myocarditis induced by coxsackie virus B3m (CVB3m) and mouse toxic myocarditis induced by adriamycin, a model of arrhythmia induced by BaCl2 and CHCl3, a model of inflammation caused by egg white and agar, along with a dynamic test of cardiac blood flow and an inhibitory test of CVB3m in vitro.

RESULTS

XJEK granules are efficacious in inhibiting CVB3m both in vitro and in vivo, protecting and curing virus myocarditis and toxic myocarditis in mice, reducing mouse death rate, serum level of LDH, AST and CK, titer of neutralizing antibodies, virus concentration of heart, and improving the abnormal ECG, pathological and ultrastructural damage of myocadium. The granules are also good for anti-inflammation, anti-myocardial ischemia, anti-arrhythmia, as well as for strengthening myocardiac contraction and increasing the serum IgG level.

CONCLUSION

Xinjerkang granules possess an inhibitory effect on virus myocarditis and toxic myocarditis.

p53/56(lyn) antisense shifts the 1,25-dihydroxyvitamin D3-induced G1/S block in HL60 cells to S phase

p53/56(lyn) is a member of the src family that is predominantly expressed in hematopoietic cells and is thought to play a role in cellular proliferation. In this study, we demonstrate the participation of p53/56(lyn) in 1,25-dihydroxyvitamin D(3) (1, 25D(3))-induced growth arrest in HL60 cells. We show that the mRNA and protein levels of p53/56(lyn) are markedly elevated after 1, 25D(3) treatment, which is accompanied by an increase of p53/56(lyn) kinase activity. We also demonstrate that treatment with p53/56(lyn) antisense oligodeoxynucleotides reverses the 1,25D(3)-induced G1/S block, and results in an accumulation of cells with S-phase DNA content. BrdU pulse-chase experiments reveal that this accumulation results from an increased proportion of cells actively synthesizing DNA, which are inhibited from exiting the S-phase compartment. These results indicate that upregulation of p53/56(lyn) contributes significantly to the G1/S growth arrest induced by 1,25D(3) in HL60 cells and thus its activation may be a desirable outcome of chemotherapeutic regimens.

De novo RNA synthesis catalyzed by HCV RNA-dependent RNA polymerase

The 65 kDa RNA-dependent RNA polymerase (NS5B), encoded by the hepatitis C virus (HCV) genome, is a key component involved in viral replication. Here we provide the direct evidence that purified HCV polymerase catalyzed de novo RNA synthesis in a primer-independent manner using homopolymers and HCV RNA as templates. The enzyme could utilize both polyC and polyU as templates for de novo RNA synthesis, suggesting that NS5B specifically recognized pyrimidine bases for initiation. More importantly, NS5B also catalyzed de novo RNA synthesis with an HCV RNA template; the resulting nascent RNA products, smaller than the template used, contained ATP as the first nucleotide. These results indicate that the newly synthesized RNAs did not result from template self-priming and suggest that a replication initiation site in the HCV RNA genome is a uridylate.

[Studies on antitussive, antiasthmatic, expectorant and anti-inflammatory effects of Jin'an kechuan granules]

OBJECTIVE

To study the pharmacologic effect of Jin'an Kechuan granules.

METHOD

Routine antitussive, antiasthmatic and expectorant methods were used.

RESULT

Jin'an Kechuan granules in the doses of 16, 8, 4 g.kg-1 ig could significantly decrease the frequency of cough caused by ammonia water in mice, and increase the secretion of phenol red from mouse tracheas in a dose-dependent manner. The granules also help increase the threshold voltage to induce cats to cough, prolong the latent period of asthma induced by histamine and acetylcholine mixture, and antagonize the contraction of isolated trachea strips induced by histamine and acetylcholine in guinea pigs. Jin'an Kechuan granules had inhibitory effects on common bacteria in the respiratory tract as well as on the swelling of acute inflammation in mice and rats.

CONCLUSION

Jin'an Kechuan granules have antitussive, antiasthmatic, expectorant and anti-inflammatory, antibacterial effects.

1,25-dihydroxyvitamin D(3)-induced retardation of the G(2)/M traverse is associated with decreased levels of p34(cdc2) in HL60 cells

Cellular differentiation of neoplastic cells after exposure to 1, 25-dihydroxyvitamin D(3) (1,25 D(3)) is accompanied by altered cell cycle regulation. In previous studies, blocks in both G(1)/S and G(2)/M checkpoints have been observed in 1,25D(3)-treated HL60 cells, but the mechanism of the 1,25D(3)-induced G(2)/M block has not been previously reported. In this study, we show by cell cycle analysis, using bromodeoxyuridine pulse-chase labeling, that the G(2)/M block in 1,25D(3)-treated HL60 cells is incomplete. We also demonstrate that although the 1,25D(3)-treated cells exhibit elevated levels of cyclin B1, Cdc25C, and Cdk7, which are positive regulators of the G(2)/M traverse, these cells have decreased protein levels of p34(cdc2) and decreased p34(cdc2) kinase activity. This provides potential mechanisms for the observed accumulation of cells in the G(2) cell cycle compartment and occasional polyploidization following treatment of HL60 cells with 1,25D(3). The data also suggest that the ability of some cells to traverse this block may be the result of cellular compensatory mechanisms responding to decreased p34(cdc2) activity by increasing the levels of other regulators of the G(2) traverse, such as cyclin B1, Cdc25C, and Cdk7.

Butyrate-induced G2/M block in Caco-2 colon cancer cells is associated with decreased p34cdc2 activity

Butyrate, a short-chain fatty acid, has been reported to inhibit proliferation and stimulate differentiation in multiple cancer cell lines. Whereas the effects of butyrate on cellular differentiation are well documented, the relationship between butyrate-induced differentiation and its effect on cell cycle traverse is less well understood. The purpose of this study was to investigate the effects of butyrate on the regulatory proteins of the G2/M traverse in the Caco-2 colon cancer cell model. We demonstrated that the inhibition of proliferation and increased cellular differentiation after treatment of Caco-2 cells with butyrate were associated with a significant G2/M cell cycle block. Although protein levels of the major G2/M regulatory protein, p34cdc2, were unchanged, a decrease in p34cdc2 activity was noted. Despite this decrease in activity, the inhibitory tyrosine phosphorylation of p34cdc2 was decreased, suggesting that other factors are responsible for the decreased kinase activity. The reduced activity of p34cdc2 provides a possible mechanism for the accumulation of Caco-2 cells in the G2/M cell cycle compartment following exposure to butyrate. This cell system provides a new model for studies of G2/M cell cycle perturbations.

Identification and characterization of human rhinovirus-14 3C protease deamidation isoform

A purified recombinant human rhinovirus-14 3C protease preparation contained only approximately 50% active enzyme as titrated using specifically designed irreversible 3C protease inhibitors. Analysis of the purified 3C protein by isoelectric focusing showed differently charged 3C isoforms that had isoelectric points (pI) of 8.3 (55%) and 9.0 (45%), with the latter one being consistent with the predicted pI of the human rhinovirus-14 3C protein. Further analysis indicated that the pI 8.3 protein was the deamidated form of 3C, and it displayed approximately 10-fold reduced cleavage activity relative to the original 3C protease sample. Peptide mapping followed by sequence analysis revealed that a single asparagine, Asn-164, was deamidated to aspartic acid in the pI 8.3 isoform. Converting Asn-164 to Asp by site-directed mutagenesis resulted in a mutated 3C protease with extremely low activity, as seen with the pI 8.3 isoform, indicating a role of Asn-164 in substrate recognition and binding. In addition, the deamidated 3C protease was found to be present in vivo, and its abundance was related to the viral replication cycle. Moreover, mutant virus carrying Asp-164 showed reduced viability in infected cells. Taken together, our data suggest that 3C protein deamidation plays a role in the regulation of its enzymatic activity.

Design, synthesis, and evaluation of azapeptides as substrates and inhibitors for human rhinovirus 3C protease

A series of azapeptides was prepared and assessed as inhibitors of the human rhinovirus 3C protease. Boc-VLFaQ-OPh was a slow-turnover substrate that gave transient (ca. 1-2 h) inhibition as it underwent hydrolysis. Boc-VLFaG-OPh gave very slow but essentially irreversible inhibition.

Constitutive equations of symmetrical triple layer piezoelectric benders

Piezoelectric triple layer benders, with a structure of two piezoelectric top and bottom layers sandwiched by a non-piezoelectric elastic central layer, are one of the most commonly used piezoelectric devices. In this paper, we present the derivation of the constitutive equations of a symmetrical triple layer piezoelectric bender under different excitation conditions. The constitutive equations are presented by a 4x4 matrix with an external moment M, an external tip force F, a uniform load p, and an applied electric voltage V as the extensive parameters, with the generated tip angular deflection (slope) alpha, tip deflection delta, volume displacement v, and electric charge Q as the internal parameters. Further analysis on the electromechanical behavior of the triple layer piezoelectric bender can be made on the constitutive equations.

Electromechanical coupling and output efficiency of piezoelectric bending actuators

Electromechanical coupling mechanisms in piezoelectric bending actuators are discussed in this paper based on the constitutive equations of cantilever bimorph and unimorph actuators. Three actuator characteristic parameters, (e.g., electromechanical coupling coefficient, maximum energy transmission coefficient, and maximum mechanical output energy) are discussed for cantilever bimorph and unimorph actuators. In the case of the bimorph actuator, if the effect of the bonding layer is negligible, these parameters are directly related to the transverse coupling factor lest. In the case of the unimorph actuator, these parameters also depend on the Young's modulus and the thickness of the elastic layer. Maximum values for these parameters can be obtained by choosing proper thickness ratio and Young's modulus ratio of elastic and piezoelectric layers. Calculation results on four unimorph actuators indicate that the use of stiffer elastic material is preferred to increase electromechanical coupling and output mechanical energy in unimorph actuators.

Protease inhibitors as potential antiviral agents for the treatment of picornaviral infections

The picornavirus family contains several human pathogens including human rhinovirus (HRV) and hepatitis A virus (HAV). In the case of HRVs, these small single-stranded positive-sense RNA viruses translate their genetic information into a polyprotein precursor which is further processed mainly by two viral proteases designated 2A and 3C. The 2A protease (2Apro) makes the first cleavage between the structural and non-structural proteins, while 3C protease (3Cpro) catalyzes most of the remaining internal cleavages. It has been shown that both 2Apro and 3Cpro are cysteine proteases but their overall protein folding is more like trypsin-type serine proteases. Due to their unique protein structure and essential roles in viral replication, 2Apro and 3Cpro have been viewed as excellent targets for antiviral intervention. In recent years, considerable efforts have been made in the development of antiviral compounds targeting these proteases. This article summarizes the recent approaches in the design of novel 2A and 3C protease inhibitors as potential antiviral agents for the treatment of picornaviral infections.

[The distributional clines in P susceptibility causing by the P family transposable element in Drosophila melanogaster population of China]

An extensive survey of the P family transposable element of Drosophila melanogaster in China, from the far west as Xinjiang and Xizang (Tibet) to the east coast, covered all China was provided. Strains, sampling more than 70 localities, which were collected during 1980-1995. In the term of the PM system, the phenotypic property of it was mainly M type, including Taiwan. The molecular test determined, it was M type. There were three localities, the P activity of them were higher as Q type. They are: Dalian Peninsular. Chongming island, near Shanghai and Taizhong of Taiwan. For analyzed geographically, according to the east longitudes, grouped the country to four parts. After comparison, two dividing lines were found: 1. The East longitude of 115 degrees, it was between Area II and Area III, see Fig. 4, separating the coastal from inland. Except the P susceptibility of the northeastern three provinces was little higher, about 30.37%, the most part of the east coastal, the first line, its P susceptibility was very week. Seven strains were 0, fifteen strains were under 10%; its P activity was also low, never beyond 10%. Therefore, it was appeared neutral, its average was 7.23%. That was the major neutral property of the coastal areas. The second line of little increased P susceptibility averaged about 26.67%. Then, there was the third line was, when the line was the more westward, its P susceptibility was higher, up to 87%, closing to the highest score of middlewest part of the country. From the east coast to the west, there were three gradually increased P susceptibility lines pushing forward could be found. The E 115 degrees, it was between the lines of the second and the third. 2. Besides the East Longitude of 115 degrees, there is another natural geographic line shows its potentiality, that is the Tropic of Cancer. It divided the coastal to two parts, the localities at the south of this line, they did not show the coastal characteristic, instead of neutral or very week P susceptibility, they showed very strong P susceptibility as the inland localities strains were, They were left in the inland, Area II and their position were also there. Although the most part of the coastal areas presented the eastern property of neutral; the P susceptibility of the coastal cities located at the south of the Tropic of Cancer, that was very strong M type, which was different from that of the Tropical of Australia. At the north part of the Tropic of Capricom of Australia, there was P type.

Relationship between structure and anti-oxidation of tocopherol with molecular orbit theory

AIM

To explore the relationship between different structures of tocopherol (Toc) and some phenol compounds and their anti-oxidative activities.

METHODS

Use the ab initio calculation of molecular mechanics and quantum chemistry.

RESULTS

The anti-oxidation of Toc was related to the ability to release active hydrogen, i.e., related to the O-H electron populations, frontier orbital energy (au), and the decreased amount of energy at the reaction ending stage. The order of hydroxyl O-H electron populations in different Toc model molecules were alpha < gamma < or = beta < delta, which was consistent with their anti-oxidation reported.

CONCLUSION

The molecular orbit (MO) theory and the quantum chemical parameters can be used to analyze the anti-oxidation of phenol compounds with different structures.

Lowering of p27Kip1 levels by its antisense or by development of resistance to 1,25-dihydroxyvitamin D3 reverses the G1 block but not differentiation of HL60 cells

Cyclin-dependent kinase inhibitors are proteins with functions which appear to involve regulation of cell cycle traverse, and have been suggested to have a role in cell differentiation. However, there is as yet no rigorous proof that this is the case. We have addressed the participation of one of these inhibitors, p27Kip1, in the induction of differentiation and the subsequent G1 block induced in HL60 cells by 1,25-dihydroxyvitamin D3 (1,25D3). First, it was noted that sublines of HL60 cells able to grow rapidly in the presence of 1,25D3 have protein levels of p27Kip1 lower than the levels in cells subjected to 1,25D3-induced growth inhibition, but higher than in untreated parental cells. In contrast, there was no discernible relationship between the levels of p27Kip1 and the expression of differentiation markers. Further, HL60 cells treated with 1,25D3 and an oligonucleotide antisense, but not mismatched, to p27Kip1 showed an almost complete elimination of the 1,25D3-induced G1 block, but no decrease in the expression of differentiation markers. Similar results were obtained following transient transfection with an expression vector bearing the entire p27Kip1 coding sequence in the anti-sense orientation. This is the first direct demonstration that p27Kip1 plays a role in the 1,25D3-induced G1 arrest, and that partial reduction in its levels has no effect on the induction of differentiation in HL60 cells.