Biomedical subjects

Yan-bin Wang

Publications and source records attributed to Yan-bin Wang.

12 recordsLinked to original sources

PubMed2006

[Evaluation of the ultrasonographic features of axillary lymph node metastasis in breast cancer].

OBJECTIVE: To analyze the ultrasonographic features of axillary lymph node metastasis in breast cancer patients, and to evaluate the accuracy of these features by Receiver Operating Characteristic (ROC) curve. METHODS: Ultrasonography was carried out in 113 patients (mean age 56.5 yr, range 29 - 77 yr). The ultrasonographic features of the primary tumor and the axillary lymph node were observed. Univariate analysis was performed by Chi-squared test and Fisher exact test, and multivariate analysis to determine independent significant individual variables by multiple logistic regression analysis. ROC curve analysis was done to determine the sensitivity and specificity of individual and combined ultrasonographic features in distinguishing metastatic lymph node from the normal one. RESULTS: The primary tumor size, abundance of blood supply in the primary tumor, longitudinal-transverse diameter ratio, cortex-hilum thickness ratio (on the longitudinal section), abnormal cortex thickness, distribution of intra-nodal vascularity of axillary lymph nodes were found to be statistically significant factors by univariate analysis. The primary tumor size, longitudinal-transverse ratio and cortex-hilum thickness ratio of lymph node were proved to be significant independent predictors of axillary lymph node metastasis by logistic regression analysis. Through ROC analysis, the combination of these independent ultrasonographic feature predictors was found to contribute significantly in differentiating metastatic lymph node from the normal with a sensitivity of 88.6% and specificity of 84.5%. CONCLUSION: Axillary ultrasonography is helpful in staging the axillary lymph node in breast cancer patient. The primary tumor size, longitudinal-transverse diameter ratio and cortex-hilum thickness ratio of lymph node are the main features to determine whether metastatic involvement is present or not.

Adult↗

PubMed2005

[Early diagnosis of small hepatocellular carcinoma by new contrast-enhanced ultrasound technique].

OBJECTIVE: To investigate the diagnostic value of contrast-enhanced ultrasound (CEUS) enhancement patterns of hepatocellular carcinoma (HCC) smaller than 2 cm. METHODS: From 392 cases with focal liver lesions undergoing CEUS with SonoVue and Contrast Tuned Imaging (CnTI) technique, thirty six cirrhotic patients with thirty eight HCCs with histopathological diagnosis were retrospectively analyzed in this study. Surgery or needle biopsy was performed within fifteen days after CEUS. Twenty two tumors were finally diagnosed as moderately differentiated HCC, twelve as well differentiated HCC, and four as clear cell carcinomas using Edmondson Grade system. The enhancement patterns of different histopathological HCCs were analyzed. RESULTS: Before CEUS, only 16 lesions (42.1%) were diagnosed as malignant or possibly malignant. After CEUS, 38 HCCs were enhanced in different degrees following contrast administration,of which, all the 22 moderately differentiated HCCs presented typical "fast-in and fast-out" pattern with fast enhancement in arterial phase and then a quick wash-out in the parenchymal phase. Nine (75.0%) of the 12 well differentiated HCCs presented "fast-in and slow-out" pattern. One of the 4 clear cell carcinomas presented "fast-in and fast-out", one presented "fast-in and slow-out" and the other 2 presented "slightly slow-in and slow-out" pattern. According to the enhancement patterns, 76.3% (29 tumors) were considered as malignant, while 18.4% (7 tumors) as possibly malignant, only 5.3% (2 tumors smaller than 1.5 cm) could not be diagnosed by CEUS. CONCLUSION: The identification of different enhancement patterns of various histological types of small HCCs could improve the diagnostic ability of ultrasound in cirrhotic liver. CEUS might be also helpful in detecting small HCCs. Thus CEUS could be a complementary method of enhanced CT and other imaging methods in early diagnosis of HCCs.

Adolescent↗

PubMed2005

[Prognostic factors on outcome of radiofrequency ablation of 172 primary hepatic tumors].

OBJECTIVE: To investigate the prognostic factors affecting outcome in Radiofrequency (RF) ablation of primary hepatic tumors by univariate and multivariate analyses, and to assess the therapeutic efficacy of Radio-frequency ablation. METHODS: A total of 172 patients with primary hepatic tumors underwent RF treatment in our department between 1999 and 2004. Among them, 150 patients were not the surgery candidates. The follow-up period ranged from 4 to 51 months and follow-up rate was 94.8% (163 patients). Kaplan-Meier model and log-rank test were used in univariate analyses and COX regression model was used in multivariate analyses, to identify prognostic factors for survival. RESULTS: The survival rates at half a year, 1 year, 2 year and 3 year were 91.5%, 77.4%, 55.7% and 51.2% respectively. Using univariate analyses, 24 potential factors were analyzed and 8 of them were found significant for survival. These 8 factors were Child-Pugh grade, UICC stage, AFP value before first RF, Portal hypertension, first treatment or treatment for recurrence, pathological grade, treatment purpose and method, ablative safe margin. For 116 patients who underwent RF when first diagnosis, the survival rates in patients with different tumor stage (UICC standard of hepatocellular carcinoma) at half a year, 1 year, 2 year and 3 year were estimated as follows: 96.7%, 92.3%, 81.6% and 65.3% in 33 patients of stage I-II; 91.2%, 76.3%, 56.6% and 51.4% in 83 patients of stage III-IV; There was significant difference in survival rates between patients of stage I-II and patients of stage III-IV. For 56 patients suffered from recurrent hepatic tumors, the survival rates at half a year, 1 year, 2 year and 3 year were 88.5%, 70.2%, 41.4% and 24.5%, being similar to those of stage III-IV. The 8 factors mentioned above were further analyzed by multivariate model and 3 of them were identified as prognostic factors for survival. These 3 factors included Child-Pugh grade, Portal hypertension, treatment purpose and method. CONCLUSION: Based on our statistical analysis, the prognostic factors on outcome in Radio-frequency ablation of hepatic tumors were grouped into two categories. Child-Pugh grade, and Portal hypertension were the characteristics of patients and uncontrollable. While treatment purpose and method also had significant impact on survival and was controllable during RF procedure. This information might be useful to improve treatment level of Radio-frequency ablation of hepatic tumors.

Adult↗

PubMed2005

[Radiofrequency ablation of recurrent hepatocellular carcinoma after hepatectomy].

OBJECTIVE: To assess the efficiency and safety of radiofrequency ablation (RFA) of recurrent hepatocellular carcinoma (RHCC) after hepatectomy and to investigate efficacy of RFA for patients with early and late phase recurrence, separately, setting 1 year as the cut-off between the early and late phases. METHODS: A total of 42 patients with 77 RHCC and a history of hepatic resection for hepatocellular carcinoma (HCC) underwent ultrasound-guided percutaneous radiofrequency ablation in our department and entered this study (RHCC group). The average diameter of RHCC was (3.8 +/- 1.4) cm (range, 1.5-6.6 cm). 21 of the 42 RHCC patients had Child-Pugh class A cirrhosis 19, class B and two, class C cirrhosis. The average interval between initial surgery and the diagnosis of recurrence was 22.8 months (range, 1-96 month). 42 RHCC patients were divided into two groups as early recurrence group including 20 patients with 40 RHCC, and late recurrence group including the other 22 patients with 37 RHCC according to the recurrence interval. During the same period 148 patients with 217 primary HCC were also treated by RF ablation and regarded as primary HCC group. The average diameter of primary HCC was (4.0 +/- 1.4) cm (range, 1.2-7.0 cm). Regular follow-up with enhanced CT was performed to evaluate the treatment results. Ablation was considered a success if no contrast enhancement was detected in the treated area on 1 month CT scans. RESULTS: The ablation success rate, local recurrence rate, new tumor incidence and mean survival in RHCC group were 90.5%, 14.3%, 38.1% and (28.0 +/- 3.5) months, respectively, which were similar to the corresponding results of 87.2%, 16.2%, 37.8% and (39.0 +/- 2.1) month in primary HCC group. However, when further comparison was performed between early recurrence group, late recurrence group and primary HCC group, there were some significant differences. The incidence of new tumors in early recurrence group was significantly higher than that in late recurrent group (60.0% vs. 18.2%, P = 0.005); early recurrence group survived shorter than primary HCC group [(15.4 +/- 2.3) vs. (39.0 +/- 2.1) months, P < 0.005]. The survival time was similar between late recurrence group and primary HCC group. One case was found haemorrhage after RFA and recovered with conservative treatment. No major complications occurred in the remaining 41 patients. CONCLUSIONS: RF ablation is generally effective and safe in treating RHCC. And it's more effective in late recurrence than in early recurrence.

Adult↗

PubMed2005

[Standard treatment of liver malignancies with radiofrequency ablation].

OBJECTIVE: To investigate the role of standard treatment with ultrasound-guided radiofrequency ablation (RFA) in improving the treatment level of liver malignancies. METHODS: 302 patients with 476 liver malignancies were treated with established protocol and adjuvant measures and subjected to efficiency analysis. In the 302 patients, 181 had 282 hepatocellular carcinomas (HCC) with a mean diameter of 4.2 cm, and 121 had 194 metastatic liver carcinomas (MLC) with a mean diameter of 3.9 cm. According to UICC-TNM system 50 patients (27.6%) were in stage I/II and 131 (72.4%) in stage III/IV (including 39 patients with recurrent HCC after surgical resection). A standard protocol and an individualized protocol were used to treat the tumors based on their size, shape and special location such as the distance from diaphragm, gallbladder and gastrointestinal tract. Needle placement method and operation skill for the tumor region adjacent to important structures were described. Some adjuvant measures such as supplementary fine needle localization, local saline injection and feeding vessel ablation were used to improve RFA efficacy in tumors with different features. Local ablation of bleeding site and haemostatic administration systemically were adopted to deal with bleeding. For the patients with tumor adjacent to gastrointestinal tract, prolonged fasting after the RFA procedure was required. the patients were followed up regularly to assess the treatment efficiency, and the tumor was considered complete necrosed if no viability was found on enhanced CT or enhanced US one month after RFA. RESULTS: The tumor necrosis rate was 95.7% (270/282 tumors) for HCC, 94.8% (184/194 tumors) for MLC, 91.1% (51/56 tumors) for tumor near gastrointestinal tract, 88.5% (69/78 tumors) for tumors near diaphragm, and 94.3% (49/52 tumors) for tumor near gallbladder. The local recurrence rate was 10.3% (29/282 tumors) for HCC and 14.4% (28/194 tumors) for MLC. The 1, 2 and 3 year overall survival rates were 87.6%, 67.4% and 58.6% in the HCC patients, and 87.4%, 48.2%, 25.3% in the MLC patients respectively. The 1, 2 and 3 year survival rates of 50 HCC patients in early (I-II) stages were 90.7%, 85.9% and 73.7%, respectively. The incidence of complications was 2.2% (13/583 sessions), including 5 cases of hemorrhage, 1 case colon perforation, 8 cases of injury of adjacent structures. CONCLUSION: Application of proper protocol and adjuvant measures plays an important role in improving tumor ablation rate. Knowledge about possible complications and their control may increase the treatment efficacy and help to promote the use of RFA technique.

Carcinoma, Hepatocellular↗

PubMed2005

[Efficacy of radiofrequency ablation of 343 patients with hepatic tumor and the relevant complications].

OBJECTIVE: To investigate the treatment efficacy of radiofrequency ablation (RFA) of hepatic tumors and the relevant complications. METHODS: A total of 343 patients with 778 hepatic tumors underwent ultrasound-guided RFA (582 procedures). There were 212 cases of hepatic cellular carcinoma (HCC) with 448 tumors, and the average largest diameter was 4.0 cm. Of all the patients, 63 (29.7%) were in the stage of I-II (UICC Systems) and 149 (70.3%) in stage of III-IV (including 43 patients with tumor recurrence after surgical resection). There were 131 cases of metastatic liver carcinoma (MLC), with 330 metastases in the liver, the average diameter was 3.9 cm, and the liver metastases of 91 patients (69.5%) came from gastrointestinal tract. The patients were treated using the relatively standard protocol. Crucial attention must be paid to monitoring the abnormal changes in ultrasound images as well as the vital signs of the patients to find the possible hemorrhage and peripheral structure injury in time. The tumors were considered ablated successfully if no viability was found on enhanced CT within 24 hours or 1 month after RFA. The patients were followed up for 2-62 months. RESULTS: The ablation success rate for HCC was 95.5% (428/448 tumors), and the rate for MLC was 96.4% (318/330 tumors). The local tumor recurrence rates for HCC and MLC were 8.5% (38/448 tumors) and 11.8% (39/330 tumors), respectively. A total of 138 patients (40.2%) underwent repeated ablations for 2-11 times because of tumor recurrence or metastasis. The first, second and third years survival rates were 87.7%, 67.4% and 56.8% for HCC patients, 81.6%, 50.8% and 27.2% for MLC patients, respectively. The survival rate from 63 early-stage HCC patients were 92.9%, 82.8% and 74.5%, respectively. The major complication rate in this study was 2.4% (14 of 582 procedures). The complications which consisted of mechanical and thermal injuries usually occurred during or shortly after the RFA treatment. There were 5 hemorrhages, 1 colon perforation, 5 injuries of adjacent structures, 2 bile leakages and 1 skin burn. CONCLUSION: RFA, as a minimally invasive local treatment, has become an effective and relatively safety alternative for the patients of hepatic tumors, even of advanced live tumor, tumor recurrence, liver metastases which are unresectable or difficult to treat with traditional therapies. Knowledge about possible complications and their control may increase the treatment efficacy and help to promote the use of RFA technique.

Adult↗

PubMed2005

The design and application of DNA chips for early detection of SARS-CoV from clinical samples.

BACKGROUND: SARS coronavirus has been identified as the cause of severe acute respiratory syndrome (SARS). Few tests allow confirmation or exclusion of SARS within the first few days of infection. A gene chip is a useful tool for the study of microbial infections mainly for its capability of performing multi-target analysis in a single test. OBJECTIVES: Investigate the possibility of early detection of SARS virus from clinical samples using the gene chip-based method. STUDY DESIGN: We purified RNA from SARS-CoV obtained from routinely collected peripheral blood and sputum samples of 34 patients who had been identified as probable SARS patients by following the interim U.S. case definition. Four segments of the SARS-CoV were amplified using reverse transcription-nested PCR and the products examined using the 70-mer gene chips for SARS-CoV detection. RESULTS: A blind-test of both peripheral blood and sputum specimens lead to the positive detection of SARS-CoV in 31 out of 34 patients. SARS-CoV was not found in peripheral blood or sputum specimens from three patients. Two of the 34 patients were only 3 days post-onset of symptoms and were subsequently confirmed to be SARS positive. Our results indicate that the gene chip-based molecular test is specific for SARS-CoV and allows early detection of patients with SARS with detection rate about 8% higher than the single PCR test when the sputum sample is available.

Blood↗

PubMed2005

[Study on the RNA of severe acute respiratory syndrome (SARS) associated coronavirus in the blood and excretion of convalescent patients with SARS].

OBJECTIVE: To examine the RNA of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) in the blood and excretion of convalescent patient with SARS for prevention and treatment of the disease. METHODS: A total of 276 samples, including plasma, urine, feces and sputum, obtained from 23 convalescent patients with SARS were studied at 3 time-points at least 21 days after the onset of symptoms. RNA was extracted and nested reverse transcription-polymerase chain reaction (RT-PCR) was carried out using SARS-CoV specific primers. RESULTS: Among the 276 samples, SARS-CoV RNA was detected in 6 cases (38.8%) by nested RT-PCR. The positive rates of SARS-CoV RNA was 5.8% in feces and 2.9% in sputum samples but SARS-CoV RNA was not detectable in plasma and urine of all the cases. CONCLUSION: The existence of SARS-CoV RNA in the excretion of some convalescent patients with SARS showed that the excretion from these patients should be carefully treated whilthe re-transmission of SARS by which, should be further studied.

Adolescent↗

PubMed2005

[A new calibration transfer method based on target factor analysis].

A new calibration transfer method based on target factor analysis is proposed.The performance of the new method compared with the piecewise direct standardization method. This method was applied to two data sets, of which one is a simulation data set, and the other is an NIR data set composed of benzene, toluene, xylene and isooctane. The results obtained with this new method are at least as well as those obtained by PDS with the biggest improvement occurring when the spectra have some non-linear responses.

Algorithms↗

PubMed2005

[Receptor-binding ability of fragments 260-600 and 397-796 of SARS-associated coronavirus spike protein].

BACKGROUND: To investigate the interaction between the host cell and the truncated S fragments to identify the receptor-binding domain of the spike (S) protein of SARS-associated coronavirus (SARS-CoV). METHODS: Two different fragments S260-600 and S397-796 of the SARS-CoV S protein were expressed in Escherichia coli (E.coli) using a pET expression vector, respectively. The two recombinant proteins were separately verified by Western blot, purified by nickel-affinity chromatography, and incubated with Vero cells, a susceptible cell line of SARS-CoV infection, for cell binding assay. After the sequential probing with sera from convalescent SARS-patients and FITC-labeled anti-human IgG, the cells were analyzed by flow cytometry. The NIH 3T3 cell, a non-permissive cell line of SARS-CoV infection, was used as controls. RESULTS: The recombinant proteins S260-600 and S397-796 were efficiently expressed in an insoluble form in E.coli. The appropriate expression of the proteins was confirmed by Western blotting using both SARS patients' sera and anti-6 x histidine antibody. The flow cytometry results showed that the both proteins were able to bind Vero cells, but the binding ability of S260-600 was somewhat stronger than that of S397-796. In contrast, the S260-600 protein did not bind NIH3T3 cells. CONCLUSION: Both S260-600 and S397-796 exhibited different receptor binding activity. The S260-600 fragment probably contains the important receptor binding domain and could be a potential candidate for the development of SARS vaccine and anti-SARS therapeutics.

Animals↗

PubMed2004

[Preparation and characterization of monoclonal antibodies against SARS-associated coronavirus nucleocapsid protein].

OBJECTIVE: To obtain monoclonal antibodies (McAbs) against severe acute respiratory syndrome (SARS) associated coronavirus (SARS-CoV) nucleocapsid (N) protein to develop diagnostic test for SARS and study the pathogenesis of the disease. METHODS: BALB/c mice were immunized with purified N protein of SARS-CoV. Hybridoma cell lines secreting monoclonal antibodies against SARS-associated coronavirus nucleocapsid were established after cell fusion with mouse splenic cells and SP2/0 cells. The specificity of the McAbs obtained was examined by Western blot and indirect fluorescence assay. Epitopes reacted with the McAbs were preliminarily located through Western blot by expressing truncated N proteins. RESULTS: After cell fusion and three rounds of cell cloning, six hybridoma cell lines secreting monoclonal antibodies specifically against SARS-CoV nucleocapsid were obtained. Western blot and indirect fluorescence assay showed that the McAbs reacted specifically with nucleocapsid protein and SARS-CoV. Among the six McAbs, three recognize the epitopes located in the N-terminus of the protein, whereas the others reacted with those located in the C-terminus. CONCLUSION: The anti-SARS-CoV nucleocapsid McAbs were developed and these McAbs may be useful in the development of diagnosis assays and basic research of SARS.

Animals↗

PubMed2004

[Developing robust near infrared calibration models].

There are three approaches to developing robust near infrared calibration models, including spectral pretreatment such as differentiation, Piecewise Multiplicative Scatter Correction (PMSC), Finite Impulse Response (FIR), and Orthogonal Signal Correction (OSC), to remove external variations, selecting wavelengths which are insensitive to external variations, and constructing temperature-hybrid calibration models. In this paper, these three strategies were investigated based on reforming gasoline NIR spectra collected at different temperatures in order to develop robust RON and benzene calibration models against temperature. It has been found that with only spectral pretreatment even OSC method fails to obtain satisfactory results, which could not remove the effects caused by temperature fluctuation. Selecting wavelengths by genetic algorithms and constructing temperature-hybrid calibration models, in which spectra measured at different temperature are combined into one calibration set, are both good approaches to developing robust NIR calibration models against temperature. The latter seems better because it needs no special knowledge and extra software, but thenon-linear effects should be considered in practical applications.

Calibration↗