[Show abstract][Hide abstract] ABSTRACT: Objectives:
To evaluate the performance of clustering methods used in the prognostic assessment of categorical clinical data for hepatocellular carcinoma (HCC) patients in China, and establish a predictable prognostic nomogram for clinical decisions.
Materials and methods:
A total of 332 newly diagnosed HCC patients treated with hepatic resection during 2006-2009 were enrolled. Patients were regularly followed up at outpatient clinics. Clustering methods including the Average linkage, k-modes, fuzzy k-modes, PAM, CLARA, protocluster, and ROCK were compared by Monte Carlo simulation, and the optimal method was applied to investigate the clustering pattern of the indices including platelet count, platelet/lymphocyte ratio (PLR) and serum aspartate aminotransferase activity/platelet count ratio index (APRI). Then the clustering variable, age group, tumor size, number of tumor and vascular invasion were studied in a multivariable Cox regression model. A prognostic nomogram was constructed for clinical decisions.
The ROCK was best in both the overlapping and non-overlapping cases performed to assess the prognostic value of platelet-based indices. Patients with categorical platelet-based indices significantly split across two clusters, and those with high values, had a high risk of HCC recurrence (hazard ratio [HR] 1.42, 95% CI 1.09-1.86; p<0.01). Tumor size, number of tumor and blood vessel invasion were also associated with high risk of HCC recurrence (all p<0.01). The nomogram well predicted HCC patient survival at 3 and 5 years.
A cluster of platelet-based indices combined with other clinical covariates could be used for prognosis evaluation in HCC.
Asian Pacific journal of cancer prevention: APJCP 07/2014; 15(14):5721-7. DOI:10.7314/APJCP.2014.15.14.5721 · 2.51 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Rabies is a major public-health problem in developing countries such as China. Although the recent re-emergence of human rabies in China was noted in several epidemiological studies, little attention was paid to the reasons behind this phenomenon paralleling the findings of the previous reports. The purpose of this study is thus first to characterize the current trends of human rabies in China from 1990 to 2007, and then to define better recommendations for improving the post-exposure prophylaxis (PEP) schedules delivered to rabies patients.
The most updated epidemiological data for 22527 human rabies cases from January 1990 to July 2007, retrieved from the surveillance database of reportable diseases managed by the Ministry of Health of China, were analysed. To investigate the efficiency for the post-exposure treatment of rabies, the details of 244 rabies patients, including their anti-rabies treatment of injuries or related incidents, were ascertained in Guangdong provincial jurisdiction. The risk factors to which the patients were predisposed or the regimens given to 80 patients who received any type of PEP were analysed to identify the reasons for the PEP failures.
The results from analysis of the large number of human rabies cases showed that rabies in China was largely under control during the period 1990-1996. However, there has been a large jump in the number of reported rabies cases since 2001 up to a new peak (with an incidence rate of 0.20 per 100000 people) that was reached in 2004, and where the level has remained until present. Then, we analysed the PEP in 244 rabies cases collected in the Guangdong province in 2003 and 2004, and found that 67.2% of the patients did not seek medical services or did not receive any PEP. Further analysis of PEP for the 80 rabies patients who received any type of PEP indicated that almost all of the patients did not receive proper or timely treatment on the wounds or post-exposure vaccination or rabies immunoglobulins.
While the issue of under-reporting of rabies in previous years may well be a factor in the apparent upwards trend of human rabies in recent years, the analysis of PEP in the Guangdong province provides evidence that suggests that the failure to receive PEP was a major factor in the number of human cases in China. Thus, the data underline the need for greatly improved availability and timely application of high-quality anti-rabies biologicals, both vaccines and immunoglobulins, in the treatment of human bite victims. Controlling dog rabies through pet vaccination schemes may also play a huge role in reducing the rate of human exposure. Education of the public, health care staff and veterinarians will also help to change the current situation.
[Show abstract][Hide abstract] ABSTRACT: The resurgence of severe acute respiratory syndrome (SARS) is still a threat because the causative agent remaining in animal reservoirs is not fully understood, and sporadic cases continue to be reported. Developing high titers of anti-SARS hyperimmune globulin to provide an alternative pathway for emergent future prevention and treatment of SARS.
SARS coronavirus (CoV)F69 (AY313906) and Z2-Y3 (AY394989) were isolated and identified from 2 different Cantonese onset SARS patients. Immunogen was prepared from SARS-CoV F69 strain. Six health horses were immunized 4 times and serum was collected periodically to measure the profile of specific IgG and neutralizing antibodies using indirect enzyme-linked immunosorbent assay and a microneutralization test. Sera were collected in large amounts at the peak, where IgG was precipitated using ammonium sulphate and subsequently digested with pepsin. The product was then purified using anion-exchange chromatography to obtain F(ab')2 fragments.
The specific IgG and neutralizing antibody titers peaked at approximately week 7 after the first immunization, with a maximum value of 1:14210. The sera collected at the peak were then purified. Fragment of approximately 15 g F(ab')2 was obtained from 1litre antiserum and the purity was above 90% with the titer of 1:5120, which could neutralize the other strain (SARS-CoV Z2-Y3) as well.
This research provides a viable strategy for the prevention and treatment of SARS coronavirus infection with equine hyperimmune globulin, with the purpose of combating any resurgence of SARS.
[Show abstract][Hide abstract] ABSTRACT: The non-structural proteins (nsp or replicase proteins) of coronaviruses are relatively conserved and can be effective targets for drugs. Few studies have been conducted into the function of the severe acute respiratory syndrome coronavirus (SARS-CoV) nsp5. In this study, bioinformatics methods were employed to predict the secondary structure and construct 3-D models of the SARS-CoV GD strain nsp5. Sequencing and sequential comparison was performed to analyze the mutation trend of the polymerase nsp5 gene during the epidemic process using a nucleotide-nucleotide basic local alignment search tool (BLASTN) and a protein-protein basic local alignment search tool (BLASTP). The results indicated that the nsp5 gene was steady during the epidemic process and the protein was homologous with other coronavirus nsp5 proteins. The protein encoded by the nsp5 gene was expressed in COS-7 cells and analyzed by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This study provided the foundation for further exploration of the protein's biological function, and contributed to the search for anti-SARS-CoV drugs.
[Show abstract][Hide abstract] ABSTRACT: The rapid transmission and high mortality rate made severe acute respiratory syndrome (SARS) a global threat for which no efficacious therapy is available now. Without sufficient knowledge about the SARS coronavirus (SARS-CoV), it is impossible to define the candidate for the anti-SARS targets. The putative non-structural protein 2 (nsp2) (3CL(pro), following the nomenclature by Gao et al, also known as nsp5 in Snidjer et al) of SARS-CoV plays an important role in viral transcription and replication, and is an attractive target for anti-SARS drug development, so we carried on this study to have an insight into putative polymerase nsp2 of SARS-CoV Guangdong (GD) strain.
The SARS-CoV strain was isolated from a SARS patient in Guangdong, China, and cultured in Vero E6 cells. The nsp2 gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and cloned into eukaryotic expression vector pCI-neo (pCI-neo/nsp2). Then the recombinant eukaryotic expression vector pCI-neo/nsp2 was transfected into COS-7 cells using lipofectin reagent to express the nsp2 protein. The expressive protein of SARS-CoV nsp2 was analyzed by 7% sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). The nucleotide sequence and protein sequence of GD nsp2 were compared with that of other SARS-CoV strains by nucleotide-nucleotide basic local alignment search tool (BLASTN) and protein-protein basic local alignment search tool (BLASTP) to investigate its variance trend during the transmission. The secondary structure of GD strain and that of other strains were predicted by Garnier-Osguthorpe-Robson (GOR) Secondary Structure Prediction. Three-dimensional-PSSM Protein Fold Recognition (Threading) Server was employed to construct the three-dimensional model of the nsp2 protein.
The putative polymerase nsp2 gene of GD strain was amplified by RT-PCR. The eukaryotic expression vector (pCI-neo/nsp2) was constructed and expressed the protein in COS-7 cells successfully. The result of sequencing and sequence comparison with other SARS-CoV strains showed that nsp2 gene was relatively conservative during the transmission and total five base sites mutated in about 100 strains investigated, three of which in the early and middle phases caused synonymous mutation, and another two base sites variation in the late phase resulted in the amino acid substitutions and secondary structure changes. The three-dimensional structure of the nsp2 protein was successfully constructed.
The results suggest that polymerase nsp2 is relatively stable during the phase of epidemic. The amino acid and secondary structure change may be important for viral infection. The fact that majority of single nucleotide variations (SNVs) are predicted to cause synonymous, as well as the result of low mutation rate of nsp2 gene in the epidemic variations, indicates that the nsp2 is conservative and could be a target for anti-SARS drugs. The three-dimensional structure result indicates that the nsp2 protein of GD strain is high homologous with 3CL(pro) of SARS-CoV urbani strain, 3CL(pro) of transmissible gastroenteritis virus and 3CL(pro) of human coronavirus 229E strain, which further suggests that nsp2 protein of GD strain possesses the activity of 3CL(pro).
Chinese medical journal 06/2005; 118(9):707-13. · 1.05 Impact Factor