To investigate the role of immunity-related medical conditions in the etiology of pancreatic cancer, we analyzed data from a population-based case-control study of pancreatic cancer conducted in ...Shanghai during 1992 and 1993. Information on prior histories of selected auto-immune diseases and allergic conditions was obtained from 108 incident pancreatic-cancer cases and 275 age- and gender-frequency matched controls by face-to-face interviews using a structured questionnaire. A prior history of auto-immune diseases was associated with a 2-fold elevated risk of pancreatic cancer (95% CI = 1.0-4.2), with an indication of a dose-response relation for the number of reported diseases. In contrast, a prior history of allergic condition was related to reduced risk (OR = 0.6, 95% CI = 0.4-1.1). With the possible exception of drug allergy, such an inverse association was seen for virtually all allergic conditions., although none of the OR was statistically significant. This study suggests that host immune function may be involved in the etiology of pancreatic cancer. Further investigations into the mechanism of these observed associations are warranted.
Support vector machines (SVM), as a novel learning machine, was used to develop the non-linear quantitative structure–mobility relationship model of the peptides based on the calculated descriptors ...for the first time. The molecular descriptors representing the structural features of the compounds included the constitutional and topological descriptors calculated by CODESSA program, which can be obtained easily without optimizing the structure of the molecule, and CPSA (charged partial surface area) descriptors obtained by SYBYL software. The MLR method was used to select the descriptors responsible for the electrophoretic mobility of peptides and develop the linear model. The prediction result of the SVM model (
ɛ
=
0.04,
γ
=
0.002 and
C
=
100) is much better than that obtained by MLR method. The RMS error of the training set, the test set and the whole set is 0.0569, 0.0553, 0.0565 and the prediction correlation coefficient is 0.925, 0.912 and 0.922, respectively. The prediction results are in agreement with the experimental values. This paper provided a new and effective method for predicting the electrophoretic behavior of peptide and some insight into what structural features are related to the electrophoretic mobility of peptides. Moreover, it also offered an idea about dealing with the structural optimization and obtaining their structural descriptors for biomacromolecules.
Five series totalling 51 of sinapyl alcohol derivatives were designed and synthesized. Their cytotoxicity analyses were performed on six human tumor cell lines such as PC-3, CNE, KB, A549, BEL-7404, ...and HeLa. Certain sinapyl alcohol derivatives showed significant cytotoxic activities. Compound
14d exhibited especially potent cytotoxicity against the BEL-7404 cell line with an IC
50 value of 0.7
μM, which showed more cytotoxic activity than the positive control, cisplatin. The structure–cytotoxicity relationships were discussed and the CoMFA analysis was performed using the cytotoxic data against HeLa cells as a template.
The immobilization behavior of lysozyme (LYZ) in mesoporous silicas (MPSs) with controlled morphologies has been investigated. The effects of entrance amount (EA) on the quantity and rate of ...immobilization of enzymes have been investigated due to the successful morphological control of MPSs. EA increases with the decrease of particle size of MPSs, leading to a significant improvement of immobilization ability. Rod-like SBA-15 (∼1–2 μm in length) shows a faster adsorption rate and larger immobilization amount than that for conventional SBA-15 (∼20 μm in length). It is observed that the adsorption rate of enzyme within MPSs is independent of the initial enzyme concentration. Increasing temperature favors a fast immobilization process of LYZ into MPSs. A maximum equilibrium adsorption amount of LYZ into rod-like SBA-15 is ∼500 mg/g at all temperatures under study (4–55 °C). However, for conventional SBA-15, this maximum equilibrium adsorption amount cannot be observed within 48 h even at high temperature. A strong interaction between LYZ and MPSs is observed, resulting in very small amount of LYZ released by MPSs. Such conclusions may be important to understand the mechanism of protein immobilization within MPSs and potentially useful for applications of MPSs in biocatalysts or biosensors.
Mesoporous silica encapsulating upconversion luminescence NaYF4 nanorods with uniform core−shell structures have been successfully synthesized by the surfactant-assistant sol−gel process. The ...thickness of ordered mesoporous silica shells can be adjusted from 50 to 95 nm by varying the amount of hydrolyzed silicate oligomer precursors from tetraethyl orthosilicate (TEOS), which further influences the BET surface area, pore volume, and the luminescence intensity. After coated with mesoporous silica shells, the hydrophobic nanorods is rendered to hydropholic simultaneously. The obtained β-NaYF4@SiO2@mSiO2 core−shell nanorods possess high surface area (71.2−196 m2 g−1), pore volume (0.07−0.17 cm3 g−1), uniform pore size distribution (2.3 nm), and accessible channels. Furthermore, the uniform core−shell nanorods show strong upconversion luminescence property similar to the hexagonal upconversion cores. The open mesopores can not only provide convenient transmission channels but also offer the huge location for accommodation of large molecules, such as fluorescent dyes and quantum dots. The secondary-excitation fluorescence of Rhodamine B is generated from the upconversion rare-earth fluoride nanorods cores to the fluorescent dyes loaded in the mesoporous silica shells.
The electrophoretic mobilities of 26 substituted aromatic acids in two different aqueous–alcoholic (ethanol and methanol) solvents in capillary zone electrophoresis were predicted based on support ...vector machine (SVM) using five molecular descriptors derived from the structures of the substituted aromatic acids, the dielectric constant of mixed solvents and the energy of the highest occupied molecular orbital of the methanol and ethanol. The molecular descriptors selected by stepwise regression were used as inputs for radial basis function neural networks (RBFFNs) and SVM. The results obtained using SVMs were compared with those obtained using the regression method and RBFFNs. The prediction result of the SVM model is better than that obtained by regression method and RBFFNs. For the test set, a predictive correlation coefficient
R = 0.9974 and mean square error of 0.2590 were obtained. The prediction results are in very good agreement with the experimental values.
Recently, the fingerprinting approach using chromatography has become one of the most potent tools for quality assessment of herbal medicine. Due to the complexity of the chromatographic fingerprint ...and the irreproducibility of chromatographic instruments and experimental conditions, several chemometric approaches such as variance analysis, peak alignment, correlation analysis, and pattern recognition were employed to deal with the chromatographic fingerprint in this work. To facilitate the data preprocessing, a software named Computer Aided Similarity Evaluation (CASE) was also developed. All programs of chemometric algorithms for CASE were coded in MATLAB5.3 based on Windows. Data loading, removing, cutting, smoothing, compressing, background and retention time shift correction, normalization, peak identification and matching, variation determination of common peaks/regions, similarity comparison, sample classification, and other data processes associated with the chromatographic fingerprint were investigated in this software. The case study of high pressure liquid chromatographic HPLC fingerprints of 50 Rhizoma chuanxiong samples from different sources demonstrated that the chemometric approaches investigated in this work were reliable and user friendly for data preprocessing of chromatographic fingerprints of herbal medicines for quality assessment.
Glucose uptake by heart, skeletal muscle, and adipose tissue is acutely regulated by insulin, which stimulates facilitative glucose transport, at least in part, by promoting the translocation of ...transporters from an intracellular pool to the plasma membrane. cDNAs encoding the major human insulin-responsive glucose transporter have been isolated and indicate that the insulin-responsive glucose transporter expressed by heart, skeletal muscle, and adipose tissue is a 509-amino acid protein having 65.3, 54.3, and 57.5% identity with the erythrocyte/HepG2, liver, and fetal muscle glucose transporters, respectively. The gene encoding the insulin-responsive glucose transporter (designated GLUT4) was mapped to the p11---p13 region of the short arm of human chromosome 17 by analyzing its segregation in a panel of reduced human-mouse somatic cell hybrids. In situ hybridization to prometaphase chromosomes indicated that GLUT4 was in band p13. A common two-allele restriction-fragment-length polymorphism (RFLP) was identified with Kpn I, and linkage of this RFLP to other polymorphic DNA markers in this region of chromosome 17 provides a set of probes that will be useful for examining the role of this gene in the pathogenesis of diabetes mellitus.
To investigate the clinical characteristics of severe acute respiratory syndrome (SARS) and find out its effective treatment.
A total of 106 cases of SARS were analyzed prospectively.
In this group, ...56 were male and 50 female, aged from 15 to 81 years average (36 +/- 10) years. Common symptoms included fever (98.1%), chills (75.5%), cough (71.7%), headache and breathless (both 43.4%), diarrhea (24.5%) and rare rales in the lungs (11.2%). Laboratory test showed leukopenia (34.0%), lymphopenia (81.1%) and an extraordinary decrease of CD(4)(+) T cells (98.1%). Other rare abnormalities included liver injury (elevated alanine aminotransferase in 7.6%) and thrombocytopenia (3.8%). Almost all patients suffered from hypoxemia (PaO(2) less than 90 mm Hg in 90.2%, less than 70 mm Hg in 28.6%). Chest radiographs showed that unilateral focal patchy involvement in 34.0% of the patients, and unilateral multifocal or bilateral involvement were 11.3% and 46.2% respectively. Treatment regimens included small doses of steroi
To determine its diagnostic value, we evaluated glutathione S-transferase alpha (GST-alpha) expression in a large number of renal cell carcinomas (RCCs). GST-alpha messenger RNA (mRNA) levels from 70 ...renal neoplasms were analyzed with complementary DNA (cDNA) microarray chips containing 21,632 cDNA clones. Furthermore, 348 primary renal tumors and 24 metastatic RCCs were subjected to immunohistochemical analysis with a GST-alpha-specific antibody. GST-alpha mRNA was elevated significantly (11.4-fold) in a majority of clear cell RCCs (28/43 65.1%; 28/39 71.8% with adjustments for informative spots) compared with other kidney tumors (1/27 3.7%). Strong and diffuse GST-alpha immunoreactivity was demonstrated in a majority of clear cell (166/202 82.2%; mean intensity, 2.41) and metastatic clear cell RCCs (17/24 70.8%; mean intensity, 2.62). Other renal tumor types did not exhibit significant GST-alpha immunoreactivity, confirming mRNA results. Through cDNA microarrays and immunohistochemical analysis, we demonstrated GST-alpha as a biomarker for clear cell RCCs.
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