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Biomedical subjects

K Zhao

Publications and source records attributed to K Zhao.

At least 55 records · Page 3Linked to original sources
PubMed2000

Role of p38 protein kinase in heat-induced Raw cells apoptosis.

OBJECTIVE: To elucidate the role of p38 in heat-induced apoptosis in the monocytic cell line Raw264.7. METHODS: Apoptosis was detected using flow cytometric analysis, DNA electrophoresis, Westero blot and a protein kinase assay. RESULTS: A marked increased in p38 activity was detected 15 min after heating and reached maximal activity 30 min post stimulation, then returned to the pre-stimulated level 2 h later. The percentage of apoptotic cells was obviously increased 3 h after heating. Stimulation of p38 preceded the induction of apoptosis, and the p38 specific inhibitor, FHPI, can inhibit thermal injury induced cell apoptosis. CONCLUSIONS: p38 activation is required for heat-induced apoptosis in Raw264.7 cells, and stimulation of the p38 signaling pathway contributes to cell death.

Animals↗
PubMed2000

[Long-term follow-up results of microsurgical treatment for glossopharyngeal neuralgia].

OBJECTIVE: To discuss effective surgical methods for the treatment of glossopharyngeal neuralgia. METHODS: During 1986 - 1998, 21 patients with glossopharyngeal neuralgia were treated microsurgically. Of whom, 5 patients were treated by microvascular decompression (MVD), 4 by MVD combined with rhizotomy of glossopharyngeal nerve root and upper 1st to 2nd rootlets of vagus nerve root, and 12 by rhizotomy of glossopharyngeal nerve root and upper 1st to 2nd rootlets of vagus nerve root. RESULTS: Neuralgia disappeared in all patients postoperatively. In 3 patients, occasional coughing episodes occurred postoperatively. One of the 3 patients also suffered from mild hoarseness and swallowing difficulty. All patients were followed up on average 7.2 years with no recurrence. CONCLUSIONS: MVD, rhizotomy of glossopharyngeal nerve root and upper 1st to 2nd rootlets of vagus nerve and their combination are effective for the treatment of glossopharyngeal neuralgia. Operative methods should be chosen according to the following two points: compression of nerve roots by affected vessels or not; and the condition of compression.

Adult↗
PubMed2000

[Pharmacognostical studies on the roots of Stellera chamaejasme and S. chamaejasme f. chrysantha].

Morphological and histological characters of the roots of Stellera chamaejasme L. and S. chamaejasme L. f. chrysantha S. C. Huang, used as the origins of the Chinese medicine Langdu, were described and illustrated with line drawings. TLC analyses of the above two drugs were also undertaken. These studies provide referencial informations for the quality control, development and identification of these two drugs.

Chromatography, Thin Layer↗
PubMed2000

[Pharmacognostical studies on the roots of Euphorbia stracheyi].

Morphological and histological characters of the roots of Euphorbia stracheyi Boiss., a traditional Chinese medicine, were described and illustrated with line drawings. TLC analysis of the above drug was also undertaken. These studies provide referencial information for clinics, quality control, development and identification of this crude drug.

Chromatography, Thin Layer↗
PubMed2000

[Pharmacognostical studies on the roots of Euphorbia fischeriana].

Morphological and histological characters of the roots of Euphorbia fischeriana Steud., used as one of the origins of traditional Chinese medicine Langdu, were described and illustrated with line drawings. TLC analysis of the above drug was also undertaken. These studies provide referencial informations for clinics, quality control, development and identification of this crude drug.

Chromatography, Thin Layer↗
PubMed2000

[Synthesis and characterization of complex of NdL3.2H2O].

The binary solid complexes using rare earth ion Nd3+ with the ligand L (L = O-chorophenoxyacetic acid and 3-methoxybenzoic acid) has been synthesized in this work. The chemical formula of the complex was determined to be NdL3.2H2O by elemental analysis. The composition structure and properties of this type of complex were tentatively investigated by the analysis of molar conductivity, TG-DTA, IR and UV.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1999

In vitro percutaneous absorption enhancement of propranolol hydrochloride through porcine epidermis by terpenes/ethanol.

The purpose of this study was to investigate the mechanism(s) of percutaneous absorption enhancement of propranolol hydrochloride (PHCL) across porcine epidermis by terpenes (e.g. menthone and limonene) in combination with ethanol. The in vitro percutaneous absorption experiments were performed using Franz diffusion cells. The solubility of PHCL in control and enhancer solutions was determined through high-performance liquid chromatography. Partitioning of PHCL to powdered SC from control or enhancer solutions was also determined in order to investigate the binding of PHCL to the SC from the SC/enhancer system. Fourier transform infrared spectroscopy (FT-IR) was employed to study the biophysical changes in stratum corneum (SC) lipids. The in vitro macroscopic barrier properties were investigated by measuring transepidermal water loss (TEWL) using Tewameter. Five percent menthone or limonene in combination with ethanol (EtOH) (menthone/EtOH or limonene/EtOH) significantly increased (P<0.05) the flux of PHCL through porcine epidermis in comparison to the control (EtOH). The partitioning of PHCL to the SC from the SC/enhancer system was also significantly greater than the SC/control system. The above enhancers showed a decrease in the peak heights and areas for both asymmetric and symmetric C-H stretching absorbances in comparison with the untreated SC, indicating the SC lipids extraction. Menthone/EtOH and limonene/EtOH enhanced (P<0.05) the in vitro TEWL through the epidermis in comparison to the control. Thus, an enhancement in the flux of PHCL by menthone/EtOH and limonene/EtOH is due to SC lipid extraction, macroscopic barrier perturbation, and improvement in the partitioning of the drug to the SC.

Animals↗
PubMed1999

Effect of ethanol/propylene glycol on the in vitro percutaneous absorption of aspirin, biophysical changes and macroscopic barrier properties of the skin.

The effect of the solvent systems ethanol (EtOH), propylene glycol (PG) and combinations thereof was examined on the in vitro percutaneous absorption of the antithrombotic, aspirin, through porcine epidermis. Biophysical changes in the stratum corneum lipids were studied through the use of Fourier transform infrared (FTIR) spectroscopy. Macroscopic barrier properties of the epidermis were examined through the use of in vitro transepidermal water loss (TEWL). The flux of aspirin increased with increasing concentrations of EtOH in the solvent systems. The maximum flux of aspirin was achieved by 80% EtOH in combination with 20% PG beyond which (i.e. 100% EtOH) there was no increase in the flux. FTIR spectroscopic study was enacted in order to determine the biophysical properties of the stratum corneum when the solvents were applied. The FTIR spectra of the stratum corneum treated with 80% EtOH/20% PG showed a maximum decrease in absorbance for the asymmetric and symmetric C&z. sbnd;H peaks, which suggests a greater loss of the lipids in the stratum corneum layers. In vitro TEWL studies allowed an investigation into the macroscopic barrier integrity properties of the stratum corneum. The TEWL results indicated that each of the solvent systems significantly enhanced (P<0.05) in vitro TEWL in comparison to the control. In conclusion, 80% EtOH/20% PG enhanced the percutaneous absorption of aspirin by perturbing the macroscopic barrier integrity of the stratum corneum and through a loss of stratum corneum lipids.

Animals↗
PubMed1999

CeReS-18 inhibits growth and induces apoptosis in human prostatic cancer cells.

BACKGROUND: Polypeptide growth factors are positive and negative regulators of prostatic growth and function, and many positive regulators of growth in the prostate have been extensively studied. However, very few inhibitors of prostate cell proliferation have been identified. We have isolated a unique 18-kDa sialoglycopeptide (CeReS-18) which inhibits cell proliferation of three separate lines of human prostate cancer cells, as well as inducing cellular cytotoxicity via an apoptotic pathway unrelated to the Bcl-2 family of proteins. METHODS: Cell cycle inhibition was analyzed by direct cell counts with a Coulter (Miami, FL) cell counter. Apoptotic cells were analyzed by electron microscopy, annexin V-fluorescein isothiocyanate (FITC) staining, fluorescence microscopy, and propidium iodide uptake measured with a fluorescence-activated cell sorter. Expression of the proteins of the Bcl-2 family was detected by Western blot analysis. RESULTS: We found that CeReS-18 inhibits cell proliferation of androgen-responsive, LNCaP.FGC human prostate cancer cells, as well as of androgen-nonresponsive DU-145 and PC3 human prostate cancer cells. Furthermore a, fivefold increase over the inhibitory concentration of CeReS-18 elicited a cytotoxic response by all three cell lines. We thus characterized the cytotoxic mechanism as apoptotic in nature, and we measured the expression of several members of the Bcl-2 family in PC3 cells upon treatment with CeReS-18. CONCLUSIONS: The data indicate that CeReS-18 is a potent inhibitor of cellular progression through the cell cycle by both androgen-responsive and androgen-nonresponsive human prostate cancer cells. In addition, treatment of both types of cells with increased concentrations of CeReS-18 induces cellular cytotoxicity, characterized as apoptosis.

Annexin A5↗
PubMed1999

Cancer in asbestos-exposed occupational cohorts: a meta-analysis.

OBJECTIVE: To examine existing asbestos-exposed occupational cohorts and apply a meta-analytic technique to determine the magnitude of association between exposure and lung cancer and to investigate other cancer sites that may be related to such an exposure. METHODS: We summarized the data from 69 asbestos-exposed occupational cohorts reporting on cancer morbidity and mortality. Data were extracted regarding numbers of deaths for each cancer, numbers of mesotheliomas, occupations and latency for respiratory, gastrointestinal, urinary and lymphohematopoietic cancers. For each cancer, we calculated a meta-SMR and examined heterogeneity of results using a chi-square test and by calculating a Z-statistic for each study. To examine the dose-response effect, we divided the studies into tertiles according to the percentage of mesothelioma deaths that served as a proxy estimation of asbestos exposure. RESULTS: Lung cancer data demonstrated meta-SMRs of 163 and 148 with and without latency, respectively, with significant heterogeneity of results even after stratification according to occupational groups. Stratification of lung cancer studies according to percentage of mesothelioma deaths showed a dose-response effect. Z-scores ranged from -12.21 to + 29.49. Analysis for laryngeal cancer yielded meta-SMRs of 157 and 133 with and without latency, respectively, demonstrating homogeneous results across studies but accompanied by no evidence of a dose-response effect. Data for gastrointestinal cancers showed no evidence of a significant association and no dose-response effect. Kidney cancer demonstrated statistically non-significant meta-SMRs of 120 (95% CI 88-160) and 111 (95% CI 94-131) with and without latency respectively. CONCLUSIONS: This meta-analysis demonstrates a wide variability of the association between occupational asbestos and lung cancer. There was a suggestion of an association between asbestos and laryngeal carcinoma and no clear association with other cancers.

Adult↗
PubMed1999

Nitric oxide and peroxynitrite. The ugly, the uglier and the not so good: a personal view of recent controversies.

Nitric oxide, a gaseous free radical, is poorly reactive with most biomolecules but highly reactive with other free radicals. Its ability to scavenge peroxyl and other damaging radicals may make it an important antioxidant in vivo, particularly in the cardiovascular system, although this ability has been somewhat eclipsed in the literature by a focus on the toxicity of peroxynitrite, generated by reaction of O2*- with NO* (or of NO- with O2). On balance, experimental and theoretical data support the view that ONOO- can lead to hydroxyl radical (OH*) generation at pH 7.4, but it seems unlikely that OH* contributes much to the cytotoxicity of ONOO-. The cytotoxicity of ONOO- may have been over-emphasized: its formation and rapid reaction with antioxidants may provide a mechanism of using NO* to dispose of excess O2*-, or even of using O2*- to dispose of excess NO*, in order to maintain the correct balance between these radicals in vivo. Injection or instillation of "bolus" ONOO- into animals has produced tissue injury, however, although more experiments generating ONOO- at steady rates in vivo are required. The presence of 3-nitrotyrosine in tissues is still frequently taken as evidence of ONOO- generation in vivo, but abundant evidence now exists to support the view that it is a biomarker of several "reactive nitrogen species". Another under-addressed problem is the reliability of assays used to detect and measure 3-nitrotyrosine in tissues and body fluids: immunostaining results vary between laboratories and simple HPLC methods are susceptible to artefacts. Exposure of biological material to low pH (e.g. during acidic hydrolysis to liberate nitrotyrosine from proteins) or to H2O2 might cause artefactual generation of nitrotyrosine from NO2- in the samples. This may be the origin of some of the very large values for tissue nitrotyrosine levels quoted in the literature. Nitrous acid causes not only tyrosine nitration but also DNA base deamination at low pH: these events are relevant to the human stomach since saliva and many foods are rich in nitrite. Several plant phenolics inhibit nitration and deamination in vitro, an effect that could conceivably contribute to their protective effects against gastric cancer development.

Animals↗
PubMed1999

An NMR study of the structural basis of the wide range of pharmacological functions of acetylsalicylic acid.

The interaction between acetylsalicylic acid (aspirin) and membrane was studied by NMR spectra. (1) NMR spectra showed acetylsalicylic acid did not insert into membrane; (2) 1H NMR spectrum recorded by spin-echo pulse sequence showed protons of the aromatic ring interacted with membrane; (3) the change of spin-lattice relaxation (T1) of 31P was ascribed to the association of acetylsalicylic acid to the polar head of lecithin; (4) the self-diffusion coefficient measured by pulsed field gradients NMR showed the mobility of acetylsalicylic acid was restricted by membrane and that acetylsalicylic acid changed membrane viscosity. Based on the results, the relationship between the interaction and the mechanism of the wide pharmacological functions of acetylsalicylic acid is discussed.

Aspirin↗
PubMed1999

[The effect of EBNA-1 ribozyme on the ability of tumor genesis of lymphoblastoid cell lines in SCID mice].

OBJECTIVE: To explore the effect of EBNA-1 specific ribozyme on the tumor genesis ability of lymphoblastoid cell lines (LCLs) in severe combined immunodeficiency (SCID) mice. METHODS: Using molecular cloning technique, recombinant adenovirus vectors expressing EBNA-1 ribozyme (RZ1) or its inactive mutant (RZ1mut) were constructed as Ad.RZ1 or Ad.RZ1mut. Recombinant adenoviruses were generated by homologous recombination and isolated by plaque formation. LCLs were established and infected with recombinant adenovirus and then injected in SCID mice (1 x 10(7) cells/animal). The SCID mice were sacrificed six weeks after injection, then the tumors were excised from these mice and their size and weight were measured. The expression of EBNA-1 ribozyme and EBNA-1 mRNA in the tumor was analyzed by RT-PCR, and the expression of EBNA-1 protein in the tumor was detected by Western blot. RESULTS: The tumors (0.27 +/- 0.18) g formed from the Ad.RZ1-treated LCLs were much smaller than those of the untreated LCLs (1.04 +/- 0.27) g or LCLs treated with control vector of adenovirus (1.12 +/- 0.32) g (P < 0.01), and also smaller than those of Ad.RZ1mut-treated LCLs (0.76 +/- 0.28) g (P < 0.05). The expression of EBNA-1 mRNA and protein in the tumors of Ad.RZ1-treated LCLs decreased significantly than that of other groups. CONCLUSIONS: Adenovirus delivery of EBNA-1 ribozyme was able to suppress LCL tumors significantly and depress the tumor genesis ability of B lymphocyte induced by EBV.

Adenoviruses, Human↗
PubMed1999

[Modificated epiglottic laryngoplasty].

OBJECTIVE: To investigate the surgical method and effect of laryngeal rehabilitation of patients with glottic carcinoma (T3 category) after extended partial laryngectomy. METHOD: 36 cases were operated with modificated epiglottic laryngoplasty. The materials for laryngoplasty included the epiglottic and one lateral partial thyroid cartilage and muscle-cartilage membrane flap and one arytenoid cartilage. The modificated technique was designed. RESULT: 33 cases were postoperatively in pulling-out-tube. The voice of 30 cases was clear, loud and comprehensible, but low and hoarse voice in other 3 cases. The 3 and 5 year survival rates were 89.3% and 77.3% respectively. The 3 and 5 year stable rates of laryngeal function were 95.6% and 94.1% respectively. CONCLUSION: The modificated epiglottic laryngoplasty was effective surgical method for the patients with glottic carcinoma (T3 category).

Aged↗
PubMed1999

[Glossus flap for hypopharyngeal reparation].

OBJECTIVE: To research the surgical type for hypopharyngeal reparation. METHOD: The glossus flap with glossus deep arterial was made to repairing hypopharyngeal breach after total laryngotomy and partial hypopharyngotomy in 12 cases of repeated laryngeal carcinoma and hypopharyngeal carcinoma. RESULT: 11 cases recovered in the swallowing function after 15 days and the pharyngeal fistula took place in one case, but healed in 35 days postoperatively. The survival rates in 1 year, 3 years and 5 years were 81.8%, 66.7% and 50% respectively. CONCLUSION: The glossus flap is good material for hypopharyngeal reparation with rich blood supply, few complication and high survival rates.

Adult↗
PubMed1999

[Pharmacognostical studies on the roots of Euphorbia soongarica].

Morphological and microscopical characters of the roots of Euphorbia soongarica Boiss. used as one of the origins of the Chinese medicine Daji in Xinjiang Autonomous Region of China were described and illustrated with line drawings. TLC and HPLC analysis of the above drug was also undertaken. These studies provide referencial informations for clinics, quality control, development and identification of this crude drug.

Chromatography, High Pressure Liquid↗