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OBJECTIVE: To quantify the transmissibility of severe acute respiratory syndrome (SARS) in hospitals in mainland China and to assess the effectiveness of control measures. METHODS: We report key epidemiological details of three ma...
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OBJECTIVE: To quantify the transmissibility of severe acute respiratory syndrome (SARS) in hospitals in mainland China and to assess the effectiveness of control measures. METHODS: We report key epidemiological details of three major hospital outbreaks of SARS in mainland China, and estimate the evolution of the effective reproduction number in each of the three hospitals during the course of the outbreaks. RESULTS: The three successive hospital outbreaks infected 41, 99 and 91 people of whom 37%, 60% and 70% were hospital staff. These cases resulted in 33 deaths, five of which occurred in hospital staff. In a multivariate logistic regression, age and whether or not the case was a healthcare worker (HCW) were found to be significant predictors of mortality. The estimated effective reproduction numbers (95% CI) for the three epidemics peaked at 8 (5, 11), 9 (4, 14) and 12 (7, 17). In all three hospitals the epidemics were rapidly controlled, bringing the reproduction number below one within 25, 10 and 5 days respectively. CONCLUSIONS: This work shows that in three major hospital epidemics in Beijing and Tianjin substantially higher rates of transmission were initially observed than those seen in the community. In all three cases the hospital epidemics were rapidly brought under control, with the time to successful control becoming shorter in each successive outbreak.
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Hepatitis B virus X protein (HBx) is a multi-functional regulatory protein that is known to be involved in viral proliferation, transcriptional activation and cell growth control. However, the actual role of HBx in cell growth con...
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Hepatitis B virus X protein (HBx) is a multi-functional regulatory protein that is known to be involved in viral proliferation, transcriptional activation and cell growth control. However, the actual role of HBx in cell growth control remains controversial. In this study, the impact of HBx on cell growth in vitro and in vivo was further investigated. HBx was able to inhibit the growth of hepatocellular carcinoma (HCC) cells and induce G2/M arrest in vitro. Moreover, unlike many other G2/M arrest mechanisms, HBx did not inhibit cyclin B1-CDK1 kinase activity, but it persistently activated the cyclin B1-CDK1 kinase. In vivo, HBx inhibited tumor cell growth and induced apoptosis as well as inhibited the growth of vascular endothelial cells. In conclusion, HBx induced G2/M arrest and apoptosis through sustained activation of cyclin B1-CDK1 kinase, and negatively regulated cell growth in vitro and in vivo.
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AIMS: Semaphorin 5A, a member of semaphorin family, was originally identified as axonal guidance factor functioning during neuronal development. Here, we investigated semaphorin 5A expression in gastric cancer and explored its rol...
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AIMS: Semaphorin 5A, a member of semaphorin family, was originally identified as axonal guidance factor functioning during neuronal development. Here, we investigated semaphorin 5A expression in gastric cancer and explored its roles in gastric carcinogenesis. MAIN METHODS: The expression of semaphorin 5A was examined by reverse transcription-polymerase chain reaction (RT-PCR) analysis in six gastric cancer cell lines and detected by real-time RT-PCR and Western blotting in 30 pairs of primary gastric cancer and normal gastric mucosa tissues. RNA interference (RNAi) technique was used to generate a semaphorin 5A-silenced stable cell line. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and anchorage-independent growth as well as flow cytometry assays were conducted to examine the effect of siRNA-semaphorin 5A on gastric cancer cell growth, proliferation and apoptosis. KEY FINDINGS: Semaphorin 5A was expressed in all human gastric cancer lines and the expression of semaphorin 5A was significantly higher in cancer tissues than that in normal mucosa tissues. siRNA-mediated semaphorin 5A knockdown significantly suppressed the proliferation and anchorage-independent growth, and induced the apoptosis of gastric cancer cell line SGC7901. SIGNIFICANCE: The present study suggests that overexpression of semaphorin 5A may contribute to gastric carcinogenesis, which reveals a novel expression and function of semaphorin 5A outside the nervous system and adds more weight to our knowledge of semaphorin 5A.
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The quality assessment and control of traditional Chinese medicines (TCM) has received a great deal of attention worldwide with its tremendous increasing use. Chromatographic fingerprinting is thought to be a good approach for thi...
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The quality assessment and control of traditional Chinese medicines (TCM) has received a great deal of attention worldwide with its tremendous increasing use. Chromatographic fingerprinting is thought to be a good approach for this task and has been used for the quality assessment and control of many herbal medicines. However, there are only a few reports on the quality control of TCM preparation by chromatographic fingerprinting. In the present work, gas chromatography-mass spectrometry (GC-MS) combined with chemometric methods were used for the chromatographic fingerprint analysis and characterization of Shengui hair-growth tincture (SGHGT), which is a complex TCM prescription made from 9 herbs. Thirteen common peaks software "The Traditional Chinese Medicine Quality Control System 1.0" (TCMQCS, developed by Research Center of Modernization of Chinese Herbal Medicine, Central South University) was used to evaluate the similarities. Principal component analysis (PCA) was used for the classification of 23 batches of SGHGT samples provided by Hunan Fusheng Hairgrowth Pharmaceutical Factory. The 23 batches of samples made in different years had similar GC-MS fingerprints. Four clusters were obtained from PCA treatment according to their production year. The proposed method was validated in precision and repeatability through the calculation of relative retention times and relative peak areas of the 13 common compounds to the reference compound eugenol. The result indicated that the method is feasible and applicable for the quality control of SGHGT. SUPPORTING INFORMATION available online at http://www.thieme-connect.de/ejournals/toc/plantamedica.
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The single MYB-type protein, CAPRICE has long been thought to be a positive regulator of root hair development in Arabidopsis thaliana. To further probe the role of AtCPC and how conserved this role is across plant species, the At...
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The single MYB-type protein, CAPRICE has long been thought to be a positive regulator of root hair development in Arabidopsis thaliana. To further probe the role of AtCPC and how conserved this role is across plant species, the AtCPC gene was constitutively overexpressed in tobacco (Nicotiana tabacum). Here, we show that flowers of transformants overexpressing AtCPC displayed an unexpected defection in pigmentation. A reduction in the level of anthocyanin was detected and the severity of abnormal flavonoid phenotype correlates well with the increased expression level of AtCPC gene. We also found that transcripts of three late biosynthetic genes were substantially down-regulated. Furthermore, AtCPC could interact with other known anthocyanin regulators. Our data suggest that in a heterologous host, AtCPC acts as a repressor of anthocyanin production, from which a new evidence for better understanding of the transcriptional regulation of flavonoid biosynthesis and, an implication for the development of new varieties of tobacco and other commercially important ornamental plants are provided.
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The aim of this study was to propose novel solid lipid nanoparticles (SLNs) loaded with cell-penetrating peptide (CPP), and to evaluate their potential for oral administration of insulin. Octaarginine (R8) was used as the CPP. SLN...
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The aim of this study was to propose novel solid lipid nanoparticles (SLNs) loaded with cell-penetrating peptide (CPP), and to evaluate their potential for oral administration of insulin. Octaarginine (R8) was used as the CPP. SLNs loaded with insulin and R8 (Ra-Ins-SLNs) were prepared using the spontaneous emulsion solvent diffusion method. The morphological study of R8-Ins-SLNs showed its spherical shape using transmission electron microscopy (TEM) photography. The mean particle size, zeta potential, encapsulation efficiency (EE %) of insulin and R8 were 150.8 +/- 23.4 nm, 32.65 +/- 2.02 mV, 62.29 +/- 0.52% and 58.05 +/- 0.66%, respectively. The in vitro release of insulin or R8 from R8-Ins-SLNs was characterized by an initial rapid release and subsequent sustained release in pH 6.8 dissolution media. In vivo absorption experiments provided a relative pharmacological bioavailability (PA%) value of R8-Ins-SLN of 10.39 +/- 0.46%. These results suggest that SLNs loaded with CPP could be a promising perioral carrier for insulin.
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