Estimation of the sorption of substituted aromatic compounds onto modified clay.
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Adsorption↗
Biomedical subjects
L S Wang
Publications and source records attributed to L S Wang.
Gemcitabine and cisplatin in a multimodality treatment for locally advanced non-small cell lung cancer.
The role of new cytotoxic agents like gemcitabine has not yet been proven in the neoadjuvant settings. We designed a phase II study to test the feasibility of using gemcitabine and cisplatin before local treatment for stage III non-small cell lung cancer patients. Patients received three cycles of induction chemotherapy of gemcitabine (1000 mg m(-2), days 1, 8, 15) and cisplatin (90 mg m(-2), day 15) every 4 weeks before evaluation for operability. Operable patients underwent radical resection. Inoperable patients and patients who had incomplete resection received concurrent chemoradiotherapy with daily low dose cisplatin. All patients who did not progress after local treatment received three more cycles of adjuvant chemotherapy of gemcitabine and cisplatin. Fifty-two patients received induction treatment. Two patients had complete response and 31 patients had partial response (response rate 63.5%) after induction chemotherapy. Thirty-six patients (69%) were operable. Eighteen patients (35%) had their tumours completely resected. Two patients had pathological complete response. Median overall survival was 19.1 months, projected 1-year survival was 66% and 2-year survival was 34%. Three cycles of gemcitabine and cisplatin is effective and can be used as induction treatment before surgery for locally advanced non-small cell lung cancer patients.
Adult↗
Effects of aluminum on physiological metabolism and antioxidant system of wheat (Triticum aestivum L.).
The Al-tolerant cultivar TAM202 and the Al-sensitive cultivar TAM 105 of winter wheat (Triticum aestivum L.) were exposed to 0, 50, 75, 100 or 150 microM of Al. The absorption of Al by wheat, the growth of root, several key enzymes concerned with C, N and P metabolism, as well as key constituents of antioxidant system, were investigated. The results showed that TAM105 absorbed more Al than TAM202 and its root growth (presented by the length) was inhibited more severely. The root growth was most closely related to mononuclear Al (Ala) activity. The metabolic enzymes (presented by glucose-6-phosphate dehydrogenase, nitrate reductase and acid phosphatase) in TAM202 were Al-tolerant. Presented by superoxide dimutase (SOD) and the content of reduced glutathione (GSH) and malondialdehyde (MDA), antioxidant system in TAM202 indicated lower oxidative stress and greater ability to protect the cultivar.
Absorption↗
Effects of platelet activating factor, butyrate and interleukin-6 on cyclooxygenase-2 expression in human esophageal cancer cells.
BACKGROUND: Epidemiological studies have indicated that non-steroidal anti-inflammatory drugs (NSAIDs) can reduce the risk of esophageal squamous cell carcinoma (ESCC) by taking cyclooxygenase (COX) as the target enzyme. The pathophysiological regulation of COX-2 may play a role in carcinogenesis and in disease progression of esophageal carcinoma. METHODS: 59 ESCC samples were used to assess COX-2 expression in the tumor cells and four ESCC cell lines to investigate the effects of phorbol myristate acetate (PMA), platelet activating factor (PAF), n-sodium butyrate (n-BT) and interleukin-6 (IL-6) on the expression of COX-2. Expression of COX-2 was determined by immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR). Production of PGE2 was measured by a competitive enzyme immunoassay (CEIA). RESULTS: COX-2 expression was detected in 54.2% (32/59) of the pathological sections by IHC. COX-2 expression in ESCC cells was significantly increased following treatment with PAF and n-BT. Increased production of PGE2 was detected in the culture media, and the secreted PGE2 in the culture media was proportional to the increased COX-2 expression. The addition of IL-6 could also enhance COX-2 expression in ESCC cells. While NSAIDs could inhibit enzymatic activity of COX-2, they did not inhibit COX-2 gene expression in ESCC cells. PKC inhibitor, however, could abrogate PMA-induced COX-2 gene expression, but it did not block IL-6-induced COX-2 expression. CONCLUSIONS: Our data suggest that COX-2 expression in ESCC cells could be upregulated by PMA, PAF, n-BT and IL-6. Nonetheless, IL-6-induced COX-2 expression could be independent of PKC activation.
Adolescent↗
Bulk-like features in the photoemission spectra of hydrated doubly charged anion clusters.
We produced gaseous hydrated clusters of sulfate and oxalate anions [SO4(2-)-(H2O)n and C2O4(2-)(H2O)n, where n = 4 to 40]. Photoelectron spectra of these clusters revealed that the solute dianions were in the center of the water cluster, (H2O)n. For small clusters, these spectra were characteristic of the respective solutes, but beyond the first solvation shell (n approximately 12), features in the spectra from the solutes were diminished and a new feature from ionization of water emerged, analogous to bulk aqueous solutions. For large clusters with dimensions greater than 1 nanometer, the solute photoemission features disappeared and the spectra were dominated by the ionization of water as the solvent coverage increased. A smooth transition from gas-phase clusters to behavior of electrolyte solutions was clearly revealed, and the large solvated clusters can be used as molecular models to investigate the photophysics and chemistry of aqueous electrolyte solutions.
Journal Article↗
Thymoma is associated with an increased risk of second malignancy.
BACKGROUND: An association between thymoma and second malignancy has been suggested but has not been validated. Whether the relation is due to treatment or to other thymoma-associated conditions is unclear. METHODS: The authors studied 192 consecutive patients with thymoma and compared the incidence of second malignancies with those of 206 patients who underwent thymectomy for nonthymomatous conditions and 1426 patients with nasopharyngeal carcinoma (NPC). Detailed clinicopathologic features of thymoma patients with second malignancies were described. RESULTS: Additional malignancies were detected in 15 of 192 patients (8%) during their clinical courses. The risk for those patients was significantly greater compared with the risk for patients with nonthymomatous conditions (adjusted odds ratio [OR], 3.81; 95% confidential intervals [95%CI], 1.05-13.81; P = 0.042) and patients with NPC (adjusted OR, 4.89; 95%CI, 2.26-10.53; P < 0.0001) after adjustment for age, gender, length of follow-up, myasthenia gravis, and radiation therapy. The occurrence of second malignancies did not correlate with histologic type or stage of thymoma, radiation therapy, or myasthenia gravis. CONCLUSIONS: Thymoma is associated with an increased risk of second malignancy. The association cannot be attributed to the effect of thymectomy or radiation therapy. Patients with thymoma, even if it is benign, should be followed regularly to facilitate the early detection of other malignancies.
Adult↗
On the aromaticity of square planar Ga4(2-) and In4(2-) in gaseous NaGa4- and NaIn4- clusters.
We investigated the electronic structure and chemical bonding of two bimetallic clusters NaGa4- and NaIn4-. Photoelectron spectra of the anions were obtained and compared with ab initio calculations. We found that the ground state of the two anions contains a square planar dianion interacting with a Na+ cation. The Ga4(2-) and In4(2-) dianions both possess two delocalized pi electrons and are considered to be aromatic, similar to that recently found in Al4(2-). Using calculations for a model compound, we showed that a recently synthesized Ga4-organometallic compound also contains an aromatic -Ga4(2-)- unit, analogous to the gaseous clusters.
Journal Article↗
Overexpression of dihydrodiol dehydrogenase as a prognostic marker of non-small cell lung cancer.
By using mRNA differential display to examine specimens of non-small cell lung cancer (NSCLC), we have identified overexpression of dihydrodiol dehydrogenase (DDH) that was not detected in the corresponding normal lung tissue. Normally DDH is associated with catalysis of polycyclic aromatic hydrocarbons (PAHs) in the liver; in NSCLC cells, DDH expression would implicate an association with disease progression. In this study we investigated the prognostic significance of DDH expression in patients with NSCLC. By using immunohistochemistry, we measured DDH expression in 381 patients with NSCLC. The relationship between DDH expression and clinicopathological parameters (age, gender, smoking history, mitotic index, histological type, stage, cell differentiation, and lymphovascular invasion) was analyzed by chi2 analysis. Survival curves were plotted with the method of Kaplan-Meier, and statistical difference of survivals between different groups was compared by a log-rank test. Our results showed that DDH overexpression could be detected in 317 (83.2%) of 381 pathological sections and in 77.9% (60 of 77) of metastatic lymph nodes. Expression of DDH was confirmed by immunoblotting. Compared with patients with DDH overexpression in tumors, patients with low DDH expression had significantly lower incidence of early tumor recurrence and distant organ metastasis (46.7 versus 29.7%; P = 0.045). Interestingly, survival was also significantly better in patients with low DDH expression than in those with DDH overexpression (P = 0.0017). Using univariate analysis, we correlated three important factors, DDH overexpression, tumor stages, and gender, with poor prognosis for NSCLC patients. Nevertheless, biological function and involvement of DDH in the disease progression of NSCLC require additional studies.
Adult↗
Observation of all-metal aromatic molecules.
Aromaticity is a concept invented to account for the unusual stability of an important class of organic molecules: the aromatic compounds. Here we report experimental and theoretical evidence of aromaticity in all-metal systems. A series of bimetallic clusters with chemical composition MAl4- (M = Li, Na, or Cu), was created and studied with photoelectron spectroscopy and ab initio calculations. All the MAl4- species possess a pyramidal structure containing an M+ cation interacting with a square Al4(2-) unit. Ab initio studies indicate that Al4(2-) exhibits characteristics of aromaticity with two delocalized pi electrons (thus following the 4n + 2 electron counting rule) and a square planar structure and maintains its structural and electronic features in all the MAl4- complexes. These findings expand the aromaticity concept into the arena of all-metal species.
Journal Article↗
Expression of aminopeptidase N in bile canaliculi: a predictor of clinical outcome in biliary atresia and a potential tool to implicate the mechanism of biliary atresia.
BACKGROUND: Only a few studies on extrahepatic biliary atresia (BA) have reported that the morphological changes of bile canaliculi could predict the clinical outcome after portoenterostomy and provide differential diagnosis of neonatal jaundice. Aminopeptidase N (APN) is an ectoenzyme of bile canaliculi that is involved in bile secretion. In this study, we tried to see whether APN of bile canaliculi had a significant role in BA. PATIENTS AND METHODS: We used monoclonal antibody 9B2 to compare the expression of APN in livers with BA, neonatal hepatitis, and choledochal cysts, as well as in nontumorous portions of pediatric hepatic livers with tumors. The expression of APN in fetuses, preterm babies, and term neonates was also studied. RESULTS: A high degree of 9B2 expression in BA was closely related to poor outcome. Cholestasis in choledochal cysts, rather than neonatal hepatitis, made 9B2 expression stronger. Increasing expression of 9B2 from fetuses to neonates was noted and the degree of 9B2 expression was similar between term neonates and nontumorous portions of pediatric livers with tumors. Interestingly, some cases of BA had 9B2 expression like that of preterm babies. CONCLUSIONS: APN of bile canaliculi progressively develops from fetuses to neonates and is well developed in neonates. APN can be induced to stronger expression by obstructive jaundice. The amount of expression of APN of bile canaliculi in BA is a predictor of clinical outcome and may be a tool for implicating the mechanism of BA.
Antibodies, Monoclonal↗
Estimation of the sorption of substituted aromatic compounds on the sediment of the Yangtse River.
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China↗
Determination and estimation of aqueous solubilities and n-octanol/water partition coefficients for phenylacrylates.
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1-Octanol↗
Joint QSAR analysis using the Free-Wilson approach and quantum chemical parameters.
A new quantitative structure-activity relationship (QSAR) technique combining the Free-Wilson method and constructed quantum chemical parameters was used to simulate the aqueous solubility (Sw), 1-octanol/water partition coefficient (Kow) of 14 new synthesized benzanilide derivatives and their 96 h acute toxicity (EC50) to Daphnia magna. The mode of action of the 14 selected compounds to Daphnia magna was shown to be a complex process involving a physical partition stage and a bio-chemical reaction stage. The results also indicated that the joint (QSAR) analysis was much effective than the original Free-Wilson method and Hansch method not only in predicting properties/toxicity, but also in investigating the mode of action of chemicals.
1-Octanol↗
Ultrasonic destruction of chloroform and carbon tetrachloride in aqueous solution.
The sonochemical destruction of binary mixtures of chloroform and carbon tetrachloride in aqueous solution at 30 kHz has been studied. The influences of initial concentration, bicarbonate/chloride, and acoustical intensity on the destruction rates have been observed. It was found that the destruction of the two compounds appeared to follow pseudo-first-order reaction kinetics with the current experimental concentration range. The rate constant of chloroform for initial concentration as high as 100.4 mg/L decreased compared to initial concentration 36.13 micrograms/L, when the rate constants of carbon tetrachloride hardly changed. However, their destruction rates increased with increasing acoustical intensity and were independent of addition of bicarbonate or chloride. The resulting yield of ionic product (Cl-) for chloroform was determined.
Carbon Tetrachloride↗
New approaches for reconstructing phylogenies from gene order data.
We report on new techniques we have developed for reconstructing phylogenies on whole genomes. Our mathematical techniques include new polynomial-time methods for bounding the inversion length of a candidate tree and new polynomial-time methods for estimating genomic distances which greatly improve the accuracy of neighbor-joining analyses. We demonstrate the power of these techniques through an extensive performance study based on simulating genome evolution under a wide range of model conditions. Combining these new tools with standard approaches (fast reconstruction with neighbor-joining, exploration of all possible refinements of strict consensus trees, etc.) has allowed us to analyze datasets that were previously considered computationally impractical. In particular, we have conducted a complete phylogenetic analysis of a subset of the Campanulaceae family, confirming various conjectures about the relationships among members of the subset and about the principal mechanism of evolution for their chloroplast genome. We give representative results of the extensive experimentation we conducted on both real and simulated datasets in order to validate and characterize our approaches. We find that our techniques provide very accurate reconstructions of the true tree topology even when the data are generated by processes that include a significant fraction of transpositions and when the data are close to saturation.
Biological Evolution↗
Influence of whole peptidoglycan of bifidobacterium on cytotoxic effectors produced by mouse peritoneal macrophages.
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Animals↗
Predicting octanol/water partition coefficient using solvation free energy and solvent-accessible surface area.
The regression model for octanol/water partition coefficients (Kow), is founded with only two molecular descriptors available through quantum chemical calculations: solvation free energy (delta Gs), and solvent-accessible surface area (SASA). For the properties of 47 organic compounds from 17 types, the model gives a correction coefficient (adjusted for degrees of freedom) of 0.959 and a standard error of 0.277 log unit. It is a suitable way to predict the partition properties that are related to solute-solvent interactions in the water phase.
Kinetics↗
Development of quantitative structure activity relationships in toxicity prediction of complex mixtures.
AIM: To predict the toxicity of mixtures of halogenated benzenes (narcotics). METHODS: Acute toxicity test of single chemicals and mixtures was performed using Photobacterium phosphoreum. Partition coefficients of mixtures were calculated by a special equation. Quantitative structure-activity relationship (QSAR) studies were carried out based on results of toxicity tests, n-octanol/water partition coefficient (Kow), and partition coefficient of mixtures (Kmix). RESULTS: 1) There was a good relationship between toxicity and lgKow for single compounds. 2) QSAR analysis showed a perfect correlation between the calculated Kmix and the mixture toxicity for binary mixtures. 3) Using the QSAR model of binary mixtures, the toxicity of other related mixtures containing different composition and fraction was predicted very well. CONCLUSION: The toxicity of halogenated benzene mixtures (narcotics) was predicted by QSAR. This kind of study is helpful for assessing the toxicity of narcotic mixtures.
Benzene Derivatives↗