PubMed Health⌕ Search

Biomedical subjects

Wei Hu

Publications and source records attributed to Wei Hu.

118 records · Page 7Linked to original sources
PubMed2002

[Development of gas chromatographic method for chiral analysis of acrylic ketone alcohol and acrylic ketone acetate].

A gas chromatographic method was developed to directly determine the enantiomers of acrylic ketone alcohol and acrylic ketone acetate. Two pairs of enantiomers were nearly baseline-separated by using Model HP-5890 Gas Chromatograph with flame ionization detector and WCOT CD-Chiral-DEX CB (30 m x 0.25 mm i.d.) column. The optimum conditions were the split ratio of 30:1 for the sample injected, the flow rates of 3.7 mL/min for the carrier gas (nitrogen), 60 mL/min for the hydrogen, and 250 mL/min for the oxygen, and temperatures of 148 degrees C for the column, 230 degrees C for the injector, and 230 degrees C for the detector. The linearity and reproducibility were satisfactory. The regression coefficients were over 0.9965. The RSDs obtained were less than 1.25%. The method was further used to trace the reactants and products, and to evaluate the enzyme catalyst activity and selectivity under different conditions. The results show that the method developed is very successful.

Acrylates↗
PubMed2002

[Studies of influential factors in determination of Ca2+ by combination of FAAS with micro-column enrichment].

It have been studied that the influential factors in determination of calcium by combination of FAAS with micro-cell preconcentration. In order to the preconcentration, the ions can be adsorbed by the self-made electrochemical preconcentration micro-cell. Then the adsorbed ions instantly return into solution which is small in size and directly into FAAS. This method can greatly improve determination sensitiveness. The characteristic concentration and detection limit for the determination of Ca2+ can be improved with 1-2 order of magnitude, the characteristic concentration about 163 times. The results are satisfactory.

Adsorption↗
PubMed2002

[Development of an analysis system for X-ray cephalometry by Windows platform].

Here in this paper introduced is an analysis system for X-ray cephalometry developed through Windows platform,which includes three parts: data input, cephalometry analysis & calculation, and display & printing of diagnostic results. It has been applied in orthodontic department of Stomatological Hospital of the Fourth Military Medical University, and it is quite convenient for doctors' cephalometry diagnosis.

Cephalometry↗
PubMed1999

Application of Free-flow Electrophoresis to the Separation of Murine Lymphocytes.

Free-flow electrophoresis offers not only the all-in-solution separation process but also very gentle separation conditions, and it can be used for continuous separation and preparation, so it has been widely applied in the fields of biochemistry and cell biology. Using this technique to separate insoluble particles such as cells, both high separation efficiency and high activity and viability could be obtained. Murine lymphocytes were separated in low ionic strength triethanolamine buffer by free-flow electrophoresis, the cell fractions were detected and characterized by means of UV spectrometry, immune fluorescence labeling and flow cytometry. Results indicated that T and B lymphocytes were well separated with high viability.

Journal Article↗
PubMedDate not supplied

Activity of ALRT 1550, a new retinoid, with interferon-gamma on ovarian cancer cell lines.

Retinoids have been shown to be effective regulators of cell proliferation and differentiation in many human cancers. The major biologic activity of the retinoids is mediated by two families of nuclear receptors: retinoic acid receptors (RARs) and retinoid X receptors (RXRs). ALRT 1550 is one of the most potent RAR selective retinoids discovered to date, with 10-100 times more activity than ATRA in competitive binding and cotransfection assays and 300 times more inhibiting activity against proliferation of cervical carcinoma cell. To evaluate the role of ALRT 1550 in ovarian cancer, the growth inhibitory activity of ALRT 1550 was determined in the ATRA-resistant ovarian cancer cell line SKOV-3 and ovarian cancer cell line 2774 after exposure to concentrations of 0.1, 1, 2.5, 5, and 10 microM for 7 days. SKOV-3 showed 51%, 53%, and 68% cell growth inhibition after treatment with ALRT 1550 at concentrations of 2.5, 5, and 10 microM, respectively, and the 2774 cell line showed 46% inhibition after treatment at 10 microM. Because interferon (IFN)-gamma was found to synergistically amplify the growth inhibition of retinoids in cultured breast cancer cells, we investigated the combination of ALRT 1550 with IFN-gamma in two ovarian cancer cell lines. ALRT 1550 (5 microM) in combination with IFN-gamma at a concentration of 500 U/ml inhibited cell growth of SKOV-3 by as much as 81% (CI = 1.88). This is a 28% greater effect than with ALRT alone. Cell line 2774 showed a 69% cell growth inhibitory effect with ALRT 1550 (5 microM) in combination with IFN-gamma at a concentration of 1000 U/ml (CI = 1.03). ALRT 1550 and IFN-gamma may act synergistically in the SKOV-3 ovarian cancer cell line and additively in the 2774 cell line. In conclusion, ALRT 1550 may be a promising drug with a high biologic modulating activity against ovarian cancer. In combination with IFN-gamma, additive and perhaps synergistic effects may be seen in some ovarian cancer cell lines. Combining these two biologic modifiers for the treatment of ovarian cancer may lower the effective dose of the retinoids, thus decreasing their side effects.

Antineoplastic Agents↗
PubMedDate not supplied

Interactive approximate rendering of reflections, refractions, and caustics.

Reflections, refractions, and caustics are very important for rendering global illumination images. Although many methods can be applied to generate these effects, the rendering performance is not satisfactory for interactive applications. In this paper, complex ray-object intersections are simplified so that the intersections can be computed on a GPU, and an iterative computing scheme based on the depth buffers is used for correcting the approximate results caused by the simplification. As a result, reflections and refractions of environment maps and nearby geometry can be rendered on a GPU interactively without preprocessing. We can even achieve interactive recursive reflections and refractions by using an object-impostor technique. Moreover, caustic effects caused by reflections and refractions can be rendered by placing the eye at the light. Rendered results prove that our method is sufficiently efficient to render plausible images interactively for many interactive applications.

Algorithms↗
PubMedDate not supplied

Increased expression of heat shock protein 70 in adherent ovarian cancer and mesothelioma following treatment with manumycin, a farnesyl transferase inhibitor.

Since farnesylation by farnesyltransferase (FTase) is the first obligatory step in the signaling transduction pathway of ras p21, FTase has been the target of new anticancer treatment modalities. Famesyl transferase inhibitors (FTIs), a novel class of antitumor drugs that blocks the oncogenic activity of ras, were first developed as therapy for ras-mutated human tumors. FTIs are also capable of inhibiting tumors without ras mutations, while different mechanisms of cell growth inhibition by FTI have been proposed. In cell culture and in animal models, FTIs have been shown to be potent inhibitors of cancer cell growth. We showed that manumycin, a farnesyl pyrophosphate competitive inhibitor, inhibits ovarian and mesothelioma cancer cell growth. To examine the molecular changes after exposure to manumycin, total proteins from treated and untreated 2774 cell line were extracted and separated by two dimensional gel electrophoresis (2-DE) and detected by colloidal coomassie blue staining. The 2-DE was found reliable for comparison of protein profiles before and after manumycin treatment. Two protein spots (spot 1 and 2) appeared after manumycin treatment. Generated peptide peaks were matched by database query (prowl.rockefeller.edu/cgi-bin/ProFound) to a heat shock protein (HSP) and a modified HSP, both with MW 70 KD. The expression status of HSP 70 was confirmed by Western blot and HSP 70 ELISA using an antibody against HSP 70. The expression of HSP70 increased with the length of exposure to, and the dose of manumycin as demonstrated by ELISA. Increase in HSP70 expression was also observed by Western blot after a 48-hour treatment with manumycin in ovarian cancer cell line OVCAR3 and three other cell cultures derived from samples of patients diagnosed with ovarian cancer and mesothelioma. Our study is the first report demonstrating an up-regulation of HSP 70 in ovarian cancer cell lines and mesothelioma cell cultures after treatment with the FTI, manumycin. This up-regulation of HSP 70 may be a cellular mechanism of cell self-protection against the apoptotic process and cell death, and it may enhance resistance and account for the altered sensitivity of certain cancers to FTIs agents. HSPs may therefore be an important molecular target for drug intervention strategies.

Alkyl and Aryl Transferases↗
PubMedDate not supplied

Surgical treatment of primary duodenal adenocarcinoma.

BACKGROUND/AIMS: Our purpose was to review the outcome of the patients with primary duodenal adenocarcinoma and determine factors influencing survival. METHODOLOGY: Over a 10-year period, 43 patients with this disease were identified. Data were analyzed to assess the outcomes of treatment and predictors of survival. RESULTS: Patients had symptoms present for an average of 6 months. The most common symptom was obstructive jaundice, observed in 55.8% of the cases. Based on symptomology, primary duodenal adenocarcinoma may be classified into three categories: icteric, obstructive and illusive. The upper gastrointestinal contrast study and esophagogastroduodenoscopy were the most effective diagnostic tests, showing an accuracy of 79.5% and 86.8%, respectively. A curative resection was performed in 28 of the 43 patients (65.1%), a conventional pancreatoduodenectomy in 11, segmental duodenal resection in 16 and gastroduodenectomy in 1. The overall 5-year survival rate was 27%, which was 42 percent after curative resection. CONCLUSIONS: The respectability of the primary lesion was associated with increased survival. An aggressive surgical approach should be pursued. Pancreaticoduodenectomy is usually required for tumors of the first and second portion of the duodenum. Segmental resection may be appropriate for selected patients, especially for cancers of the distal duodenum.

Adenocarcinoma↗