Biomedical subjects

Liang Wang

Publications and source records attributed to Liang Wang.

At least 37 records · Page 2Linked to original sources

PubMed2006

Perihepatic lymph node assessment in patients undergoing partial hepatectomy for malignancy.

OBJECTIVE: To assess the value of preoperative imaging studies and the intraoperative assessment of perihepatic lymph nodes in patients undergoing partial hepatectomy for malignancy. SUMMARY BACKGROUND DATA: Perihepatic lymph node status is an important prognostic factor for patients undergoing hepatic resection for 1(o) and metastatic cancer. The value of preoperative imaging studies and intraoperative assessment of perihepatic nodes is unknown. METHODS: Perihepatic lymph nodes were sampled in 100 patients undergoing resection for 1(o) and metastatic hepatic malignancy. At the time of sampling, participating surgeons assigned a clinical suspicion score (scale, 1-5: 1 = clinically negative, 5 = clinically positive). Preoperative CT scans and PET scans were reviewed in a blinded fashion by 2 radiologists. Clinical assessment, CT, and PET scan results were analyzed in the context of the pathologic status of the lymph nodes. RESULTS: A mean of 3.2 +/- 0.2 nodes were sampled per patient. Fifteen patients had metastatic disease in perihepatic lymph nodes; 13 had suggestive findings on preoperative CT or PET, and 2 were clinically positive at exploration. Clinical assessment had a high negative predictive value (NPV) = 99% but a low positive predictive value (PPV) = 39%. Similarly, CT scans had a high NPV = 95% and a low PPV = 30%. PET scans had a NPV = 88% and a PPV of 100%. Of the 48 patients with both negative preoperative CT and PET scans, only 1 (2.1%) had metastatic nodal disease, and this was suspected based on the clinical assessment. Of the patients with negative CT and PET scans and a negative clinical assessment (n = 39), none had involved perihepatic nodes. CONCLUSIONS: In patients with 1(o) and metastatic liver cancer, the incidence of truly occult metastatic disease to perihepatic lymph nodes is low. Routine sampling of perihepatic lymph nodes will therefore have a low yield in patients without some evidence of disease on preoperative CT or PET scans or at the time of exploration.

Bile Duct Neoplasms↗

PubMed2006

Marker-controlled watershed for lymphoma segmentation in sequential CT images.

Segmentation of lymphoma containing lymph nodes is a difficult task because of multiple variables associated with the tumor's location, intensity distribution, and contrast to its surrounding tissues. In this paper, we present a reliable and practical marker-controlled watershed algorithm for semi-automated segmentation of lymphoma in sequential CT images. Robust determination of internal and external markers is the key to successful use of the marker-controlled watershed transform in the segmentation of lymphoma and is the focus of this work. The external marker in our algorithm is the circle enclosing the lymphoma in a single slice. The internal marker, however, is determined automatically by combining techniques including Canny edge detection, thresholding, morphological operation, and distance map estimation. To obtain tumor volume, the segmented lymphoma in the current slice needs to be propagated to the adjacent slice to help determine the external and internal markers for delineation of the lymphoma in that slice. The algorithm was applied to 29 lymphomas (size range, 9-53 mm in diameter; mean, 23 mm) in nine patients. A blinded radiologist manually delineated all lymphomas on all slices. The manual result served as the "gold standard" for comparison. Several quantitative methods were applied to objectively evaluate the performance of the segmentation algorithm. The algorithm received a mean overlap, overestimation, and underestimation ratios of 83.2%, 13.5%, and 5.5%, respectively. The mean average boundary distance and Hausdorff boundary distance were 0.7 and 3.7 mm. Preliminary results have shown the potential of this computer algorithm to allow reliable segmentation and quantification of lymphomas on sequential CT images.

Algorithms↗

PubMed2006

Preparation and evaluation of solid dispersions of nitrendipine prepared with fine silica particles using the melt-mixing method.

Solid dispersions (SD) of nitrendipine (NTD), a poorly water-soluble drug, were prepared using the melt-mixing method with hydrophilic silica particles (Aerosil and Sylysia) with different particle size and specific surface areas as carriers. Powder X-ray diffraction and differential scanning calorimetry evaluation showed that NTD in the SDs treated with the melt-mixing method was dispersed in the amorphous state. FT-IR spectroscopy obtained with the SDs indicated the presence of hydrogen bonding between the secondary amine groups of NTD and silanol groups of silica particles. The dissolution property of NTD in the SDs was remarkably improved regardless of the grade of silica. At the end of the dissolution test (60 min) the concentrations of NTD for the SDs with Aerosil 200 and Sylysia 350 were 8.88 and 10.09 microg/ml, corresponding to 28 and 31 times that of the original NTD crystals, respectively. The specific surface area and the adsorbed water amount of the SDs were also significantly improved. The rapid dissolution rate from the SDs was attributed to the amorphization of drug, improved specific surface area and wettability than the original drug crystals. In the stability test, powder X-ray diffraction pattern indicated that amorphous NTD in the SD with Aerosil 200 was stable for at least 1 month under the humid conditions (40 degrees C/75% RH).

Adsorption↗

PubMed2006

Abnormal beta-catenin and reduced axin expression are associated with poor differentiation and progression in non-small cell lung cancer.

We studied the expression of axin and beta-catenin and their relation to clinicopathologic factors in 100 non-small cell lung cancers (NSCLCs) by immunohistochemical analysis. The mutation in exon 3 of the beta-catenin gene was examined by polymerase chain reaction and direct sequencing. Preserved axin expression was significantly higher in well- and moderately differentiated NSCLC samples than in poorly differentiated ones. Reduced membranous expression of beta-catenin was shown in 80 cases, whereas 26 cases had aberrant nuclear expression. Poor differentiation and lymph node metastasis were associated significantly with reduced beta-catenin expression. Lower axin expression was related significantly to higher nuclear beta-catenin expression. However, this study failed to detect any exon 3 mutation in the beta-catenin gene in the 100 NSCLC samples. We conclude that reduced beta-catenin and axin expression might predict poor differentiation in NSCLC. Reduced axin expression, but not mutation in exon 3, might be an important explanation for the abnormal beta-catenin expression in NSCLC.

Adult↗

PubMed2006

Combined endorectal and phased-array MRI in the prediction of pelvic lymph node metastasis in prostate cancer.

OBJECTIVE: The objectives of our study were to evaluate the accuracy of combined endorectal and phased-array MRI in detecting pelvic lymph node metastasis (LNM) in patients with prostate cancer and to determine whether radiologists' predictions of LNM improve with the incorporation of Partin nomogram or MRI findings (or both) regarding extracapsular extension or seminal vesicle invasion. SUBJECTS AND METHODS: Between May 1999 and September 2003, 411 consecutive patients with clinically localized prostate cancer underwent MRI before surgery. Serum prostate-specific antigen (PSA) level, Gleason grade, clinical stage, greatest percentage of cancer and percentage of positive cores in all biopsy cores, presence of perineural invasion on biopsy, and likelihood of LNM based on the Partin tables (2001 version) were recorded. MRI studies were interpreted prospectively, but the risks of LNM, extracapsular extension, and seminal vesicle invasion were scored retrospectively on the basis of the MRI reports. Surgical pathology constituted the standard of reference. The accuracy of LNM prediction was assessed using areas under receiver operating characteristic curves (AUCs) and univariate and multivariate logistic regression analyses. For multivariate models, the jackknife method was used for bias correction. A p value below 0.05 denoted statistical significance. RESULTS: At surgical pathology, LNM was present in 22 (5%) of 411 patients. MRI was an independent statistically significant predictor of LNM (p = 0.002), with positive and negative predictive values of 50% and 96.36%, respectively. On multivariate analysis, prediction of lymph node status using the model that included all MRI variables (extracapsular extension, seminal vesicle invasion, and LNM) along with the Partin nomogram results had a significantly greater AUC than the univariate model that included only MRI LNM findings (AUC = 0.892 vs 0.633, respectively; p < 0.01). CONCLUSION: Incorporation of the Partin nomogram results and MRI findings regarding both extracapsular extension and seminal vesicle invasion improves the MR prediction of LNM in patients with prostate cancer.

Adult↗

PubMed2006

[Expression of hypoxia-inducible factor 1 alpha and vascular endothelial growth factor in prostate cancer and its significance].

OBJECTIVE: To study the expression of hypoxia-inducible factor 1 alpha (HIF-1 alpha) and vascular endothelial growth factor (VEGF) in prostate cancer (PCa) and its biological significance. METHODS: Specimens from 75 patients with PCa (32 cases), benign prostatic hyperplasia (BPH, 16 cases), high-grade prostate intraepithelial neoplasia (PIN, 15 cases) and normal prostate (NP, 12 cases) were comprised in the study. The PCa was divided into high Gleason score group (Gleason score > or = 7) and low Gleason score group (Gleason score < 7). Immunohistochemistry was performed with antibodies against HIF-1 alpha, VEGF and CD34. Microvessel density (MVD) was analyzed by staining with antibodies to CD34. RESULTS: The positive rates of HIF-1alpha were significantly higher in PCa (62.5%) and PIN (60.0%) than those in BPH (6.3%) and NP(0) (P < 0.05), respectively. The positive rates of VEGF were significantly higher in PCa (78.1%) and PIN (73.3%) than those in BPH (18.7%) and NP (8.3%) (P < 0.05), respectively. A higher concentration of MVD was observed in PCa (66.9 +/- 18.0) compared with those in BPH (28.3 +/- 6.9) and NP (15.3 +/- 2.9) (P < 0.05). MVD and the positive rates of HIF-1alpha and VEGF were significantly higher in high Gleason score group than those in low Gleason score group. CONCLUSION: The results suggest that the overexpression of HIF-1alpha and VEGF are closely related to PCa, and the son score group. up-regulation of HIF-1alpha and VEGF are early events in PCa.

Adult↗

PubMed2006

[Auditory capability evaluation for children after cochlear implantation using meaningful auditory integration scale].

OBJECTIVE: To analyze the auditory capability of preschool children before and after cochlear implantation using meaningful auditory integration scale (MAIS) questionnaire. METHODS: Eighty-two prelingually deaf patients participated in this study. They received a cochlear implant at the age of 3 to 6 years and 11 months. The audiologists who were trained for the research used the MAIS questionnaire. Audiologists asked for the parents' answers and recorded all the information about the device using (Q1,2) and the patient's spontaneous auditory behavioural responses including spontaneous alerting to sound Q3 approximately 6 and deriving meaning from sound (Q7 approximately 10). The evaluation was performed before operation and 1 , 3, 6 months, 1, 1.5, 2 years after switch-on. RESULTS: The scores of question 1a and 1b were not significantly different among the different periods after switch-on. The scores of question 2 to 10 were significantly different among the different periods after switch-on. CONCLUSIONS: Considerable variability across subjects' auditory ability after cochlear implantation was noted. Most of the patients showed no consistent response to sound in everyday life before implantation. After cochlear implantation, a significant increase in auditory capability occurred. The children demonstrated faster development of device using relative to spontaneous alerting to sound and deriving meaning from sound.

Auditory Perception↗

PubMed2006

[The expression and significance of eotaxin gene in nasal mucosa and CCR3 in bone marrow in model of allergic rhinitis].

OBJECTIVE: To study the expression and significance of Eotaxin gene in nasal mucosa and CCR3 in bone marrow in model of allergic rhinitis. METHOD: Twenty SD rats were randomly divided into allergic rhinitis (AR) group and normal control group. Ovalbumin (OVA) sensitized and challenged rats were used as the model of allergic rhinitis. The leucocytes in the smears of bone marrow and peripheral blood were counted, and the expression of CCR3 in bone marrow was detected by immunohistochemistry. The pathologic samples of nasal mucosa were stained with HE. The expression of Eotaxin mRNA in nasal mucosa was detected by in situ hybridization (ISH), and the expression of Eotaxin in nasal mucosa was detected by immunohistochemistry. RESULT: The ratio of eosinophils to white cells in bone marrow smears of AR group was significantly higher than that of normal control group (P < 0.01). The ratio of eosinophils to white cells in peripheral bloods mears of AR group was significantly higher than that of normal control group (P < 0.01). Eotaxin positive cell and the expression of Eotaxin mRNA in nasal mucosa of AR group were significantly higher than that of normal control group (P < 0.01). The expression of Eotaxin mRNA significantly positively correlated with the expression of Eotaxin (r = 0.804, P < 0.01). The number of Eotaxin positive cells in nasal mucosa was significantly positively correlated with the number of eosinophils in nasal mucosa of AR group (r = 0.795, P < 0.01). The ratio of CCR3 positive cells to white cells in bone marrow smears of AR group was significantly higher than that of normal control group (P < 0.01). The ratio of CCR3 positive cells to white cells was significantly positively correlated with the ratio of eosinophils to white cells in bone marrow smears of AR group (r = 0.736, P < 0.05). CONCLUSION: The expression of Eotaxin and Eotaxin mRNA in nasal mucosa increased, and the expression of CCR3 in bone marrow increased in the model of allergic rhinitis. It supplies a cooperation between CCR3 and Eotaxin to allow rapid mobilization of a pool of bone marrow eosinophils followed by recruitment to the nasal mucosa.

Animals↗

PubMed2006

[Transfection of pemt-2-cDNA inhibits the expression of cell cycle related proteins in rat CBRH-7919 hepatoma cells].

OBJECTIVES: To unravel the molecular mechanism of proliferation inhibition induced by transfection of pemt2-cDNA into rat CBRH-7919 hepatoma cells. METHODS: We started with the highly expressed PEMT2 clone. Cell culture and Western blotting techniques were used to examine the expression of cyclinD1/CDK4, cyclinE/CDK2, phospho-Rb, caspase-3, c-jun and caveolins. RESULTS: Our results showed that CDK4, CDK2, phospho-Rb and c-jun were down regulated in the pemt2 highly expressed cell clone. The high expression clone of pemt2-transfected cells also showed over expression of caspase-3. CONCLUSION: The reductions of proliferation and apoptosis of pemt2 transfected cells could be related to the G1 phase arrest induced by down-regulation of the cell cycle-associated proteins.

Animals↗

PubMed2006

[Development and equivalence evaluation of monosyllable lists of mandarin speech test materials].

OBJECTIVE: To find a good speech material in audiology routine tests and cochlear implant evaluation, the monosyllable lists which were a part of mandarin speech test materials (MSTM) were edited and recorded. The equivalence test was done for all the lists. METHODS: The professional group was set up at first, which composed of specialists of Chinese, mandarin teaching, linguistics and statistics. The principles of word selection were established according to the coherence with international speech test materials and mandarin. Ten Monosyllable lists, each of which has 50 mandarin words according to phonemic balance and criteria of speech audiometry, were edited. The balance was 3-dimension: vowels, consonants and four Chinese tones. One cassette was recorded by a male speaker (radiobroadcaster). The 72 normal hearing subjects were tested monaurally with ten monosyllable lists and the materials were presented by the earphone. The equivalence evaluation was done at the level of about 50% correct scores. RESULTS: Statistic analysis shows that 7 lists were equivalent in difficulty. They were ready for future research and clinical trial. CONCLUSIONS: The mandarin monosyllable lists were edited in terms of international standard and Chinese 3-dimension phonemic balance. Seven of them met the demands for research and clinical application.

Adult↗

PubMed2006

Dendritic cell as therapeutic vaccines against tumors and its role in therapy for hepatocellular carcinoma.

Dendritic cells (DCs) are the most potent professional antigen-presenting cells, and capable of stimulating naïve T cells and driving primary immune responses. DCs are poised to capture antigen, migrate to draining lymphoid organs, and after a process of maturation, select antigen-specific lymphocytes to which they present the processed antigen, thereby inducing immune responses. The development of protocols for the ex vivo generation of DCs may provide a rationale for designing and developing DC-based vaccination for the treatment of tumors. There are now several strategies being applied to upload antigens to DCs and manipulate DC vaccines. DC vaccines are able to induce therapeutic and protective antitumor immunity. Numerous studies indicated that hepatocellular carcinoma (HCC) immunotherapies utilizing DC-presenting tumor-associated antigens could stimulate an antitumour T cell response leading to clinical benefit without any significant toxicity. DC-based tumor vaccines have become a novel immunoadjuvant therapy for HCC.

Animals↗

PubMed2006

[Development and equivalence evaluation of spondee lists of mandarin speech test materials].

OBJECTIVE: To edit the spondee (disyllable) word lists as a part of mandarin speech test materials (MSTM). These will be basic speech materials for routine tests in clinics and laboratories. METHODS: Two groups of professionals (audiologists, Chinese and Mandarin scientists, linguistician and statistician) were set up at first. The editing principles were established after 3 round table meetings. Ten spondee lists, each with 50 words, were edited and recorded into cassettes. All lists were phonemically balanced (3-dimensions: vowels, consonants and Chinese tones). Seventy-three normal hearing college students were tested. The speech was presented by earphone monaurally. Three statistic methods were used for equivalent analysis. RESULTS: Related analysis showed that all lists were much related, except List 5. Cluster analysis showed that all ten lists could be classified as two groups. But Kappa test showed that the lists' homogeneity were not well. CONCLUSIONS: Spondee lists are one of the most routine speech test materials. Their editing, recording and equivalent evaluation are affected by many factors. This also needs multi-discipline cooperation. All lists edited in present study need future modification in recording and testing in order to be used clinically and in research. The phonemic balance should be kept.

Adult↗

PubMed2006

[Separation and purification of phosphatidylcholine in swine liver and its inhibition effect on proliferation of rat hepatoma cells].

Phosphatidylcholine (PC) in crude phospholipids from swine liver was separated and purified by using Al2O3 column chromatography with 95% alcohol as eluent. The purity was determined by thin layer chromatography on GF254 silica gel plate and with chloroform-methanol-water (65:25:4,v/v) as developing agent. The results showed that PC was completely separated from phosphatidylethanolamine (PE) by the elution with 95% alcohol, and its purity and yield reached more than 90% and 80% with a elution volume of 225 mL, and 87.6% and 87.3% with a elution volume of 425 mL respectively. The effect of the PC with different concentrations on the proliferation of rat hepatoma cell line (CBRH-7919) was determined by microculture tetrazolium (MTT) assays in vitro and was compared with that of human leukemia cell line K562. Result shows that the PC derived from the liver inhibited the growth of CBRH-7919 cells significantly. It suggested that PC derived from animal liver might function as a specific inhibitor for hepatoma cells in a concentration dependent manner.

Animals↗

PubMed2006

[Equivalence analysis of disyllabic Mandarin speech test materials].

OBJECTIVE: To evaluate the equivalence of difficulty of disyllabic Mandarin Speech Test Materials (MSTM) in order to facilitate wider use of speech audiometry in Chinese audiology clinics. METHOD: The Mandarin disyllabic materials, including 10 lists with 50 words in each, have been recorded and converted digitally into CD format. Sixty-five subjects (the age-range 18-25 years) with normal hearing who speak Mandarin well in their daily lives participated in this study. Five of them joined the pilot study, which aimed to identify a presentation level which would be used into the formal test. The other sixty subjects participated in the formal speech perception test. The results were analyzed statistically with Statistical Package for the Social Sciences Software Version 11.0 (SPSS 11.0). RESULT: Nine of the 10 lists were found to have equal difficulty with application of the ANOVA and SNK-Q statistical methods. CONCLUSION: Nine lists of 50 words of these Mandarin disyllabic materials can be considered to have equal difficulty and could be used in a clinical setting.

Adolescent↗

PubMed2006

[One case report of a laryngeal schwannoma].

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Adult↗

PubMed2005

Prediction of organ-confined prostate cancer: incremental value of MR imaging and MR spectroscopic imaging to staging nomograms.

PURPOSE: To assess retrospectively the incremental value of endorectal coil magnetic resonance (MR) imaging and combined endorectal MR imaging-MR spectroscopic imaging to the staging nomograms for predicting organ-confined prostate cancer (OCPC). MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant study and issued a waiver of informed consent for review of the MR reports and clinical data. Between November 1, 1999, and November 1, 2004, 229 patients underwent endorectal MR imaging and 383 underwent combined endorectal MR imaging-MR spectroscopic imaging before radical prostatectomy. Mean patient age was 58 years (range, 32-74 years). MR studies were interpreted prospectively by 12 radiologists who were informed of patients' clinical data. On the basis of the MR reports, the risks of extracapsular extension, seminal vesicle invasion, and lymph node metastasis were scored retrospectively from 1 to 5; the highest score was subtracted from 6 to determine a score (from 1 to 5) for the likelihood of OCPC on MR studies. The staging nomograms were used to calculate the likelihood of OCPC on the basis of serum prostate-specific antigen level, Gleason grade at biopsy, and clinical stage. Histopathologic findings constituted the reference standard. Logistic regression was used to estimate the multivariable relations between OCPC and MR findings. The area under the receiver operator characteristic curve was calculated for each model. The jackknife method was used for bias correction. RESULTS: MR findings contributed significant incremental value (P </= .02) to the nomograms in the overall study population. The contribution of MR findings was significant in all risk groups but was greatest in the intermediate- and high-risk groups (P < .01 for both). Accuracy in the prediction of OCPC with MR was higher when MR spectroscopic imaging was used, but the difference was not significant. CONCLUSION: Endorectal MR imaging and combined endorectal MR imaging-MR spectroscopic imaging contribute significant incremental value to the staging nomograms in predicting OCPC.

Adult↗

PubMed2005

Nanoscale organic and polymeric field-effect transistors as chemical sensors.

This article reviews recently published work concerning improved understanding of, and advancements in, organic and polymer semiconductor vapor-phase chemical sensing. Thin-film transistor sensors ranging in size from hundreds of microns down to a few nanometers are discussed, with comparisons made of sensing responses recorded at these different channel-length scales. The vapor-sensing behavior of nanoscale organic transistors is different from that of large-scale devices, because electrical transport in a nanoscale organic thin-film transistor depends on its morphological structure and interface properties (for example injection barrier) which could be modulated by delivery of analyte. Materials used in nanoscale devices, for example nanoparticles, nanotubes, and nanowires, are also briefly summarized in an attempt to introduce other relevant nano-transducers.

Biosensing Techniques↗

PubMed2005

[Experience of resection large clinoidal meningiomas].

OBJECTIVE: To investigate the clinical applied anatomy in the region of anterior clinoid process, and to improve the therapeutic efficacy of clinoidal tumors. METHODS: Twelve patients with large meningiomas located in clinoid were surgically treated via the extended anterior and middle fossa combined with epidural approach between January 1998 and August 2004. The surgical outcome and follow-up results were reviewed retrospectively. Supraorbital-posterional approach and cranioorbital zygomatic approach were used when tumors involved cavernous sinus. Anterior clinoid process was grinded with high-speed drilling. Supply of tumors were blocked extradurally. Tumors were resected intradurally. RESULTS: Of the 12 cases in large meningiomas located in clinoid, 8 cases had total removal of tumors, 3 patients had subtotal removal. Of the 10 patients with pre-operative severe visual deterioration, 6 patients was markedly improved, one patient unchanged and one patient worsened post-operatively. No death was found in this group. CONCLUSIONS: Using epidural approach for clinoidal meningiomas and grinding anterior clinoid process was advantageous to block tumors base blood supply and detach infraclinoidal tumors from internal carotid artery. Supraorbital-pterional approach could minimize brain retraction and was advantageous to expose superior pole of giant tumors.

Adult↗