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Biomedical subjects

C Jia

Publications and source records attributed to C Jia.

At least 19 recordsLinked to original sources
PubMed2006

Surgeon volume and postoperative mortality after oesophagectomy for cancer.

AIM: Oesophagectomy remains the curative treatment of choice for patients with localised oesophageal or cardia cancer, but severe postoperative complications are common. Our aim was to assess the association between surgeon volume and postoperative mortality after oesophagectomy. METHODS: Prospective, population-based study of Swedish residents diagnosed with oesophageal or cardia cancer, treated with oesophagectomy during the period April 2001 through December 2005. Details concerning patients, tumours, and surgery were collected from the Swedish Oesophageal and Cardia Cancer register. All 607 patients registered during the study period were included in the study. Risk of mortality 30 and 90 days after oesophagectomy was assessed using multivariable logistic regression, expressed in odds ratios (OR) with 95% confidence intervals (CI), adjusted for relevant covariates. RESULTS: The 30-day mortality in low-, medium-, and high-volume surgeon groups were 7.1%, 2.1%, and 2.6%, respectively. The corresponding 90-day figures were 11.4%, 4.8%, and 8.9%. Adjusted ORs for 30- and 90-day mortality were decreased non-significantly by 58% and 14%, respectively, among patients in the high-volume group, compared to the low-volume group (OR 0.42, 95% CI 0.10-1.80; OR 0.86, 95% CI 0.31-2.38). The mortality rates differed considerably between individual high-volume surgeons, but without any trend of further decreased risk with increasing volume among these surgeons (p values for trend 0.84 and 0.80 for 30- and 90-day mortality, respectively). CONCLUSION: Patients with resectable oesophageal cancer should be advised to choose a high-volume surgeon, but they should also be aware that differences among individual surgeons might further affect survival.

Aged↗
PubMed2006

Tamoxifen exposure and risk of oesophageal and gastric adenocarcinoma: a population-based cohort study of breast cancer patients in Sweden.

In a population-based cohort study of all women aged over 50 years with breast cancer in the Swedish Cancer Register in 1961-2003, those diagnosed before 31 December 1987 were regarded as unexposed to tamoxifen, whereas those diagnosed after that date were considered potentially exposed. Crosslinkages within the Cancer Register and the Registers of Death and Emigration enabled follow-up. Standardised incidence ratios (SIRs) of oesophageal and gastric cancer represented relative risks. Among 138 885 cohort members contributing with 1 075 724 person-years of follow-up, we found a nonsignificantly increased risk of oesophageal adenocarcinoma during the potential tamoxifen exposure period (SIR 1.60, 95% confidence interval (CI) 0.83-3.08), but the risk estimates decreased with increasing latency interval. No association was observed during the unexposed period. No increased risk of cardia adenocarcinoma was identified in either period. The risk of non-cardia gastric adenocarcinoma was increased in the potential tamoxifen period (SIR 1.27, 1.03-1.57), and almost doubled (SIR 1.86, 95% CI 1.10-3.14) in the period of longest latency (10-14 years). The corresponding overall SIR was increased in the unexposed group also, but here SIR did not increase with longer latency intervals. An increased risk of tobacco-related tumours, that is, oesophageal squamous-cell carcinoma and lung cancer, was limited to the unexposed cohort, indicating that confounding by smoking might explain the increased SIR during the unexposed period. We concluded that there might be a link between tamoxifen and risk of non-cardia gastric adenocarcinoma.

Adenocarcinoma↗
PubMed2005

Neurogenesis, migration, and apoptosis in the vomeronasal epithelium of adult mice.

The location of neurogenesis and the direction of migration of neurons in the adult mouse vomeronasal organ is controversial. Cell division occurs at the center, and particularly, at the edges of the epithelium. Newly generated cells at the center of the epithelium participate in neurogenesis, however, it is unknown to what extent dividing cells at the edges participate in growth, become apoptotic or mature into neurons. Premitotic cells were labeled with bromodeoxyuridine (BrdU) in adult mice and animals allowed to survive for different postinjection periods. The terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick end-labeling (TUNEL) method was used to show the distribution of apoptotic cells. The vertical and horizontal position of BrdU-labeled cells was analyzed as a function of postinjection survival time. Vertical and horizontal migration of BrdU-labeled cells were detected. Cells in the central portions of the epithelium migrated vertically to become neurons as demonstrated by co-expression of olfactory marker protein. Cells at the edges migrated horizontally very slowly (less than 10% of the distance from the edge to the center of the epithelium per month), thus indicating that these cells participate in cell renewal exclusively in marginal regions. Neural turnover in the mouse vomeronasal epithelium, therefore appears to occur through a process of vertical migration. Data on the distribution of apoptotic cells indicate that a number of dividing cells throughout the epithelium, but particularly at the edges, die before becoming functional neurons. Accordingly, most dividing cells at the edges probably constitute a reservoir of stem cells dying before differentiation.

Animals↗
PubMed2005

3-D correlation-based speckle tracking.

Widely-used 1-D/2-D speckle tracking techniques in elasticity imaging often experience significant speckle decorrelation in applications involving large elevational motion (i.e., out of plane motion). The problem is more pronounced for cardiac strain rate imaging (SRI) since it is very difficult to confine cardiac motion to a single image plane. Here, we present a 3-D correlation-based speckle tracking algorithm. Conceptually, 3-D speckle tracking is just an extension of 2-D phase-sensitive correlation-based speckle tracking. However, due to its high computational cost, optimization schemes, such as dynamic programming, decimation and two-path processing, are introduced to reduce the computational burden. To evaluate the proposed approach, a 3-D bar phantom under uniaxial compression was simulated for benchmark tests. A more sophisticated 3-D simulation of the left ventricle of the heart was also made to test the applicability of 3-D speckle tracking in cardiac SRI. Results from both simulations clearly demonstrated the feasibility of 3-D correlation-based speckle tracking. With the ability to follow 3-D speckle in 3-D space, 3-D speckle tracking outperforms lower-dimensional speckle tracking by minimizing decorrelation caused by pure elevational translation. In other words, 3-D tracking can push toward solely deformation-limited, decorrelation-optimized speckle tracking. Hardware implementation of the proposed 3-D speckle tracking algorithm using field programmable gate arrays (FPGA) is also discussed.

Algorithms↗
PubMed2001

A new approach to 4-alkylthio-1,3-dithiole-2-thione: an unusual reaction of a zinc complex of 1,3-dithole-2-thione-4,5-dithiolate.

[see reaction]. A new and facile approach to 4-alkylthio-1,3-dithiole-2-thione starting from easily accessible reactants was described. This approach was based on the unusual reaction of a zinc complex of 1,3-dithiole-2-thione-4,5-dithiolate with electrophilic reagents in the presence of 3-picolyl chloride hydrochloride/or 4-picolyl chloride hydrochloride/or pyridine hydrochloride.

Journal Article↗
PubMed2001

Risk factors for nodal recurrence after lymphadenectomy for melanoma.

BACKGROUND: The risk and outcome of regional failure after elective and therapeutic lymph node dissection (ELND/TLND) for microscopically and macroscopically involved lymph nodes without adjuvant radiotherapy were evaluated. METHODS: Retrospective melanoma database review of 338 patients (ELND 85, TLND 253) from 1970 to 1996 with pathologically involved lymph nodes. RESULTS: Regional recurrence occurred in 14% of patients treated with ELND (n = 12) and 28% of patients treated with TLND (n = 72; P = .009). Risk factors associated with nodal recurrence were advanced age, primary lesion in the head and neck region, depth of the primary lesion, number of involved lymph nodes, and extracapsular extension (ECE). For each nodal basin, the ELND group had a lower incidence of recurrence than the TLND group. The TLND group had larger lymph nodes, greater number of involved lymph nodes, and a higher incidence of ECE. The 10-year disease-specific survival was 51% vs. 30% for ELND and TLND, respectively (P = .0005). Nodal basin failure was predictive of distant metastasis, with 87% developing distant disease compared with 54% of patients without nodal recurrence (P < .0001). Of six patients who underwent a second dissection after isolated nodal recurrence, five patients have had a median disease-free interval of 79 months. CONCLUSIONS: After ELND or TLND, patients who have a large tumor burden (thick primary melanoma, multiply involved lymph nodes, ECE), advanced age, and a primary lesion located in the head and neck have a significantly increased likelihood of relapse and a decreased survival. Few patients present with an isolated nodal recurrence, but the majority can be salvaged by a second dissection.

Female↗
PubMed2001

Catalytic functionalization of arenes and alkanes via C-H bond activation.

Several novel synthetic reactions of arenes and alkanes discovered and investigated in our laboratory are summarized here. These include olefin arylation, hydroarylation of alkynes, hydroxylation of arenes, carboxylation of arenes and alkanes, and aminomethylation and acetoxylation of alkanes. Most of these reactions are catalyzed by highly electrophilic transition metal cationic species generated in situ in an acid medium, involving electrophilic metalation of C-H bonds of arenes and alkanes which lead to the formation of aryl-metal and alkyl-metal sigma-complexes.

Journal Article↗
PubMed2001

Chromosomal composition of micronuclei in mouse NIH 3T3 cells treated with acrylamide, extract of Tripterygium hypoglaucum (level) hutch, mitomycin C and colchicine, detected by multicolor FISH with centromeric and telomeric DNA probes.

The chromosomal composition of micronuclei (MN) induced by the model mutagens mitomycin (MMC) and colchicine (COL) as well as by acrylamide (AA) and the traditional Chinese medicine Tripterygium hypoglaucum (level) hutch (THH) in NIH 3T3 cells was analyzed by multicolor fluorescence in situ hybridization (FISH) using DNA probes for the centromere repeated minor satellite DNA and the telomeric hexamer repeat (TTAGGG). The majority of MN (78.6%) from treatment with MMC (0.1 microg/ml) did not show centromeric signals, reflecting the clastogenic action of MMC. Following treatment with COL (0.1 microg/ml), 74.5% of the MN showed centromeric signals and several telomeric signals, indicating that MN induced by this well-known aneugen were mainly composed of whole chromosomes. After treatment with AA (100, 200 and 400 microg/ml) both MN containing whole chromosomes and MN containing acentric fragments were found to increase in a dose-dependent manner, demonstrating that AA is not only a clastogen but also an aneugen. THH induced a high frequency of MN harboring whole chromosomes at all concentrations tested (5, 10 and 20 microl/ml) and produced a dose-dependent increase in fragment-containing MN, indicating that THH has both aneugenic and clastogenic potential.

3T3 Cells↗
PubMed2001

HUman MicroNucleus project: international database comparison for results with the cytokinesis-block micronucleus assay in human lymphocytes: I. Effect of laboratory protocol, scoring criteria, and host factors on the frequency of micronuclei.

Micronucleus (MN) expression in peripheral blood lymphocytes is well established as a standard method for monitoring chromosome damage in human populations. The first results of an analysis of pooled data from laboratories using the cytokinesis-block micronucleus (CBMN) assay and participating in the HUMN (HUman MicroNucleus project) international collaborative study are presented. The effects of laboratory protocol, scoring criteria, and host factors on baseline micronucleated binucleate cell (MNC) frequency are evaluated, and a reference range of "normal" values against which future studies may be compared is provided. Primary data from historical records were submitted by 25 laboratories distributed in 16 countries. This resulted in a database of nearly 7000 subjects. Potentially significant differences were present in the methods used by participating laboratories, such as in the type of culture medium, the concentration of cytochalasin-B, the percentage of fetal calf serum, and in the culture method. Differences in criteria for scoring micronuclei were also evident. The overall median MNC frequency in nonexposed (i.e., normal) subjects was 6.5 per thousand and the interquartile range was between 3 and 12 per thousand. An increase in MNC frequency with age was evident in all but two laboratories. The effect of gender, although not so evident in all databases, was also present, with females having a 19% higher level of MNC frequency (95% confidence interval: 14-24%). Statistical analyses were performed using random-effects models for correlated data. Our best model, which included exposure to genotoxic factors, host factors, methods, and scoring criteria, explained 75% of the total variance, with the largest contribution attributable to laboratory methods.

Adolescent↗
PubMed2001

[Percutaneous transluminal septal myocardial ablation in patients with hypertrophic obstructive cardiomyopathy: immediately and middle-term follow-up results].

OBJECTIVE: To evaluate the immediate and follow-up results of percutaneous transluminal septal myocardial ablation (PTSMA) in patients with hypertrophic obstructive cardiomyopathy (HOCM). METHODS: 15 patients with HOCM refractory to medication successfully underwent PTSMA under myocardial contrast echocardiography. RESULTS: The left ventricular outflow gradients (LVOTG) were reduced significantly (77.93 +/- 22.00) mm Hg to (14.8 +/- 15.0) mm Hg (P < 0.0001) immediately with a mean decrease of (5.75 +/- 2.87) mm Hg (P < 0.001) in left ventricular end diastolic pressure. The scores of SAM and mitral regurgition During a mean of 8.6 +/- 3.8(6-22) months follow-up, the patients heart function (NYHA) were greatly improved(3.4 +/- 0.5 vs 1.1 +/- 0.4, P < 0.001), and disappearance of angina pectoris, and exercise endurance improvement with steady hemodynamic improvement. CONCLUSION: PTSMA is effectively non-surgical treatment method for drug-refractory patients with HOCM.

Adolescent↗
PubMed2001

[Relations of electrolytes to the by-product CHCl3 produced in electrochemical disinfection].

OBJECTIVE: To investigate the relation of electrolytes(NaCl, Na2SO4) to the by-product CHCl3 produced in the electrochemical disinfection process. METHODS: Taking filtering water, we used the graphite and Ti (matrix)-Ti as electrodes, adjusted the current sample for analysis in different time, and determined the production of CHCl3 under different conditions. RESULTS: Na2SO4 had no effect on the production of CHCl3 in the electrolysis(P > 0.05). but NaCl had the effect and the higher the concentration of Cl- was, the more the production of CHCl3 increased. The production of CHCl3 increased with the length of electrolysis time, and it exceeded the national standard after 10 minutes' electrolysis using Ti (matrix)-Ti as electrodes. When graphite was used as electrodes, the production of CHCl3 was much less. CONCLUSION: Na2SO4 has no effect on the production of CHCl3. Our suggestion is that graphite should be used as the electrodes for electrochemical disinfection of drinking water.

Chloroform↗
PubMed2000

New method for preparation of coumarins and quinolinones via Pd-catalyzed intramolecular hydroarylation of C-C triple bonds.

A new and general method has been developed for preparation of coumarins and quinolinones by intramolecular hydroarylation of alkynes. Various aryl alkynoates and alkynanilides undergo fast intramolecular reaction at room temperature in the presence of a catalytic amount of Pd(OAc)(2) in a mixed solvent containing trifluoroacetic acid (TFA), affording coumarins and quinolinones in moderate to excellent yields with more than 1000 turnover numbers (TON) to Pd. The methodology proved to tolerate a number of functional groups such as Br and CHO. On the basis of isotope experiments, a possible mechanism involving ethynyl chelation-assisted electrophilic metalation of aromatic C-H bonds by in-situ generated cationic Pd(II) species has been discussed. Also the involvement of vinylcationic species has been suggested.

Catalysis↗
PubMed2000

Pd-catalyzed selective addition of heteroaromatic C-H bonds to C-C triple bonds under mild conditions.

Simple heteroarenes such as pyrroles and indoles undergo addition reactions to C-C triple bonds in the presence of a catalytic amount of Pd(OAc)(2) under very mild conditions, affording cis-heteroarylalkenes in most cases. The cleavage of aromatic C-H bonds is the possible rate-determining step in CH(2)Cl(2), and the addition of heteroaromatic C-H bonds to C-C triple bonds is in a trans-fashion.

Catalysis↗
PubMed2000

Efficient activation of aromatic C-H bonds for addition to C-C multiple bonds

Efficient electrophilic metalation of aromatic C-H bonds leading to new C-C bond formation through regio- and stereoselective addition to alkynes and alkenes has been realized by a catalytic amount (0.02 to 5 mole percent) of palladium(II) or platinum(II) compounds in a mixed solvent containing trifluoroacetic acid at room temperature. Various arenes undergo unexpected selective trans hydroarylation to terminal or internal C&cjs0812;C bonds inter- and intramolecularly with high efficiency (up to a turnover number of 4500 for palladium), especially for electron-rich arenes, giving thermodynamically unfavorable cis-alkenes, and the oxygen- and nitrogen-containing heterocycles. The simplicity, generality, and efficiency of this process should be very attractive to the possible industrial application for the functionalization of arenes.

Journal Article↗
PubMed2000

Nodal basin recurrence following lymph node dissection for melanoma: implications for adjuvant radiotherapy.

PURPOSE: To analyze patterns of failure in malignant melanoma patients with lymph node involvement who underwent complete lymph node dissection (LND) of the nodal basin. To determine prognostic factors predictive of local recurrence in the lymph node basin in order to select patients who may benefit from adjuvant radiotherapy. METHODS AND MATERIALS: A retrospective analysis of 338 patients undergoing complete LND for melanoma between 1970 and 1996 who had pathologically involved lymph nodes was performed. Mean follow-up from the time of LND was 54 months (range: 12-306 months). Lymph node basins dissected included the neck (56 patients), axilla (160 patients), and groin (122 patients). Two hundred fifty-three patients (75%) underwent therapeutic LND for clinically involved nodes, while 85 patients (25%) had elective dissections. Forty-four percent of patients received adjuvant systemic therapy. No patients received adjuvant radiotherapy to the lymph node basin. RESULTS: Overall and disease-specific survival for all patients at 10 years was 30% and 36%, respectively. Overall nodal basin recurrence was 30% at 10 years. Mean time to nodal basin recurrence was 12 months (range: 2-78 months). Site of nodal involvement was prognostic with 43%, 28%, and 23% nodal basin recurrence at 10 years with cervical, axillary, and inguinal involvement, respectively (p = 0.008). Extracapsular extension (ECE) led to a 10-year nodal basin failure rate of 63% vs. 23% without ECE (p < 0.0001). Patients undergoing a therapeutic dissection for clinically involved nodes had a 36% failure rate in the nodal basin at 10 years, compared to 16% for patients found to have involved nodes after elective dissection (p = 0.002). Lymph nodes larger than 6 cm led to a failure rate of 80% compared to 42% for nodes 3-6 cm and 24% for nodes less than 3 cm (p < 0.001). The number of lymph nodes involved also predicted for nodal basin failure with 25%, 46%, and 63% failure rates at 10 years for 1-3, 4-10, and > 10 nodes involved (p = 0.0001). There was no significant difference in nodal basin control in patients with synchronous or metachronous lymph node metastases, nor in patients receiving or not receiving adjuvant systemic therapy. Nodal basin failure was predictive of distant metastasis with 87% of patients with nodal basin recurrence developing distant disease compared to 54% of patients without nodal failure (p < 0.0001). On multivariate analysis, number of positive nodes and type of dissection (elective vs. therapeutic) were significant predictors of overall and disease-specific survival. Size of the largest lymph node was also predictive of disease-specific survival. Site of nodal involvement and ECE were significant predictors of nodal basin failure. CONCLUSIONS: Malignant melanoma patients with nodal involvement have a significant risk of nodal basin failure after LND if they have cervical involvement, ECE, >3 positive lymph nodes, clinically involved nodes, or any node larger than 3 cm. Patients with these risk factors should be considered for adjuvant radiotherapy to the lymph node basin to reduce the incidence of nodal basin recurrence. Patients with nodal basin failure are at higher risk of developing distant metastases.

Adult↗
PubMed2000

p53 and P-glycoprotein expression are significant prognostic markers in advanced head and neck cancer treated with chemo/radiotherapy.

The development of biological markers of response to chemo- and radiotherapy to judge benefit to risk ratios for toxic treatments is still at an experimental stage. Tumour cell death is largely by apoptosis and the p53 gene has a major influence on this. P-glycoprotein (P-gp) accumulation has been correlated with treatment failure in several types of cancer. p53 and P-gp expression were studied in 111 advanced head and neck cancers treated with radiotherapy and up to four courses of synchronous or sequential chemotherapy. The probability of survival at 5 years for patients in the trial as a whole was 27.7%, while the cohort used for this marker project was 29.4%. Among the subjects used for the marker study at the time of analysis, 13 remained disease-free and 18 were alive. Immunohistochemistry was used to assess p53 and P-gp expression; 27/111 (24%) head and neck cancers demonstrated p53/P-gp expression and 33/111 (30%) were both p53- and P-gp- negative. In univariate analysis, both p53 and P-gp expression were associated with reduced disease-free and overall survival. Multivariate analysis revealed tumour size, p53, and P-gp expression as the most powerful pretreatment prognosticators in the study cohort. Long-term follow-up results suggest that p53 and P-gp co-expression predicts the biological behaviour or the outcome following chemo/radiotherapy in advanced head and neck cancer.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

[Hemorrhagic shock increases the occurrence of bacterial translocation].

OBJECTIVE: To determine whether hemorrhagic shock (HS) increases the occurrence of bacterial translocation (BT). METHODS: 100 patients were divided into 4 groups: control group (group I, 34 patients); group with hemorrhagic shock (HS) caused by closed blunt abdominal trauma (group II, 23); group caused by closed blunt abdominal trauma without HS (group III 15); and group with HS caused by intra-abdominal viscus hemorrhage (group IV 28). Preoperative and postoperative samples were taken from peripheral blood, visceral peritoneal swab, portal vein blood, ileal mesenteric lymph node, liver and spleen biopsy respectively for aerobic and anaerobic culture. RESULTS: The positive culture rates of these groups were 6%, 65%, 13%, 68% respectively. The difference between the control and experimental groups was significant(P < 0.05). The difference was also significant between group I and II and between I and IV (P < 0.01), whereas it was not significant between I and III, and between II and IV (P > 0.05). CONCLUSION: HS increases the occurrence of BT.

Abdominal Injuries↗