Search PubMed⌕ Search

Biomedical subjects

Q Yang

Publications and source records attributed to Q Yang.

At least 199 records · Page 11Linked to original sources
PubMed2000

[Experimental study on effect of ligustrazine on peritoneal ultrafiltrative function in rats].

OBJECTIVE: To study the effect of ligustrazine on peritoneal transport in various dosages. METHODS: Forty SD rats received intraperitoneal injection of 25 ml 4.25% glucose dialysis solution (GDS) or GDS plus 40 mg/L ligustrazine (GDS-LL) or GDS plus 160 mg/L ligustrazine (GDS-HL) daily, for 45 days. Then a 4-hour dwell study was performed in each rat to evaluate the peritoneal transportation. RESULTS: The drainage volume at 4 hours was significantly lower in all the dialysis groups as compared to the control group, especially in the GDS-HL group. However, drainage volume was significantly higher in the GDS-LL group as compared to the GDS and GGS-HL groups. There were no significant differences in the peritoneal fluid absorption rate among the 3 dialysis groups. The fluid absorption rate and the direct lymphatic absorption rate were all significantly higher in the 3 dialysis groups as compared to the control group. In the GDS-LL group, the ratio of urea level in dialysis solution and in plasma (D/Purea) was not different in comparing with that in the GDS group, but the ratio of glucose concentration in dialysis solution and that in unused dialysis solution (D/D0), and urea clearance were significantly higher than those in the GDS group and the GDS-HL group. D/Purea increased in the GDS-HL group significantly. CONCLUSION: Low dose of ligustrazine adding to the dialysis solution could reduce the peritoneal damage caused by the hypertonic dialysis solution, increase the ultrafiltration function and dialysis function of peritoneum. However, high dose of ligustrazine does not display any beneficial effect, it increases the permeability of peritoneum.

Animals↗
PubMed2000

[In vitro culture of human osteoblasts].

OBJECTIVE: To modify the digestion and culture of human osteoblasts for releasing a large amount of cells. METHODS: Bone tissue was harvested and digested by trypsin for several times to remove blood cells and fibroblasts. After cultured for a couple of days in incubator, bone chips were digested again by trypsin for several times, and a large amount of pure osteoblasts were released and used for researches. The remaining chips were digested by trypsin repeatedly until enough cells were harvested. Black nodes were seen in confluent cell layer. Osteoblasts were confirmed by their unique secretion of a large amount of alkaline phosphatase (AKP), osteocalcin (OCN) and type I collagen. RESULTS: Under fluorescent microscope, black node was "golden yellow" in color, a characteristic of bone node. Secretion of AKP (2.76 +/- 0.56) IU/ml and OCN (1.875 +/- 0.549) ng/ml of osteoblasts was higher than those of fibroblasts. There was only type I collagen in supernatant without type III. CONCLUSION: The modified osteoblast digestion and culture can release a large amount of pure osteoblasts in a short period with no fibroblastic adulteration.

Alkaline Phosphatase↗
PubMed2000

[Effect of chrysotile on nitric oxide production and anti-oxidasic activity in rabbit alveolar macrophages].

This study aimed to explore the role of nitric oxide (NO) and nitric oxide synthase (NOS) in chrysotile asbestos-caused diseases. The production of NO2-/NO3- (the final product of NO) and the alterations of NOS, SOD and GSH-Px activity were investigated when rabbit alveolar macrophages (AM) were stimulated by UICC chrysotile. The results revealed that with the dosage elevation of UICC chrysotile, the rabbit alveolar macrophages showed: (1) increased mortality, decreased survival activity; (2) increased product of NO2-/NO3-, decreased SOD and GSH-Px activity; (3) increased NOS activity in the lower dosage groups, but decreased NOS activity in the higher dosage groups. There was significantly negative correlation between NO release and SOD (or GSH-Px) activity (r1 = -0.7125, P < 0.05; r2 = -0.8496, P < 0.05 respectively). Moreover, the significantly positive correlation between NO release and NOS activity was found in the lower dosage groups, but significantly negative correlation in the higher dosage groups. These findings suggest that chrysotile could induce the alveolar macrophages to increase NO release and to decrease SOD and GSH-Px activity, which may play a role in the process of asbestos-caused diseases.

Animals↗
PubMed2000

[Telomerase activity in human head and neck squamous cell carcinoma and adjacent tissues].

OBJECTIVE: To investigate the telomerase activity in human head and neck squamous cell carcinomas and their adjacent tissues and to explore its possibility of being tumor biological marker. METHOD: Thirty-two patient samples of primary head and neck squamous cell carcinoma and 15 adjacent tissues were assayed using TRA-PCR-ELISA for detection of telomerase activity. RESULT: Twenty-seven of 32 (84.4%) cancer samples and 5 of 15 (33.3%) adjacent samples were telomerase positive (P < 0.05, Chi-Square Test). The frequency of telomerase activation was lower in cancer without lymph node involvement (82.4%) than that with lymph node involvement(86.7%), but the difference has no statistical significance. Detection rate of telomerase activity in poor grading cancer (90%) is higher than that in moderate and high differentiation cancer (81.8%), although no statistical significance. No obvious correlation was found between the telomerase activity and the other clinical parameters such as primary site and staging. CONCLUSION: The finding of telomerase activity in 84.4% of primary head and neck squamous cell carcinoma samples is consistent with the concept of telomerase playing a key role in tumorigenesis. Further study is needed to determine the usefulness of this enzyme as a new molecular marker.

Biomarkers, Tumor↗
PubMed2000

[Central control of the hypothalamic-pituitary-adrenocortical axis for stress response].

Stress reaction is an adaptive response of all living organism to stressful events and essential for their survival. The main feature of stress reaction is activation of the hypothalamic-pituitary-adrenocortical (HPA) axis, central control of which is very complex. The hippocampus is involved in integration of sensory information, interpretation of environmental information, and execution of appropriate behavioral and neuroendocrine responses. The amygdala is an executor of stress behavioral, autonomic and neuroendocrine responses. The paraventricular nucleus (PVN) is responsible for initiating HPA axis stress reaction. The negative feedback regulation of stress hormones, local hypothalamic circuits and cytokines probably are involved in regulation of HPA activation.

Amygdala↗
PubMed2000

[Expression of CD44s and CD44v6 in laryngeal squamous cell carcinoma and their significance].

OBJECTIVE: To study the correlation between the expression of CD44s, CD44v6 and the clinicopathological characters of laryngeal squamous cell carcinoma (LSCC) so as to analyze the role of them in occurrence and progression of LSCC. METHOD: Expression of CD44 and CD44v6 in 46 cases of LSCC and 20 cases of adjacent normal tissues was inspected with immunohistochemical SP method. RESULT: The expression of CD44s increased significantly in lymphnode metastasis group (94.4%) and stage III-IV group (96.2%), but decreased in non-lymphnode metastasis group (67.9%) and stage I-II group (55.0%). The expression of CD44v6 was lower (21.7%), which wasn't associated with any clinicopathological characters. CONCLUSION: The role of CD44 and CD44v6 in carcinoma maybe dependent on the species, type of carcinoma, and the expression of CD44s may be a biologic marker to evaluate metastasis of LSCC.

Aged↗
PubMed2000

[A preliminary study on the incidence of cedar pollinosis in district of Wuhan].

OBJECTIVE: To investigate the incidence of cedar pollinosis in district of Wuhan. METHOD: A survey relative to cedar pollinosis was carried out in 309 students in Hubei Medical University in 1999, including questionnaire investigation, nasal inspection and scratch test. From February to April of 2000, a clinical investigation of cedar pollinosis was adopted among 205 patients of allergic rhinitis including scratch test and nasal mucosa test. RESULT: 1. The positive rate of cedar pollen scratch test of 309 students was 7.8%. 2. 59 cases (28.8%) was hypersensitive to cedar pollen clinically in allergen test. CONCLUSION: Cedar pollinosis is one kind of important pollinosis in district of Wuhan and should be paid high attention to.

Adolescent↗
PubMed2000

[The study about the characteristics of upper airway in obstructive sleep apnea syndrome].

OBJECTIVE: To investigate the upper airway (UA) characteristics of the patient's with obstructive sleep apnea syndrome (OSAS) and analyses the value of computer assisting fiberoptic pharyngoscopy with müller's maneuver (CFPMM) in topodiagnosis of OSAS. METHODS: The pharyngxes of 30 cases with OSAS and 30 controls were examined by CFPMM. The cross-section area at velo- and tongue-pharyngeal, pharyngeal collapsibility, sites of UA obstructive and their anatomical factors were measured and calculated and the correlation between the anatomical abnormalities of UA and outcomes of polysomnography (PSG) were analysed. RESULTS: 1. CFPMM can accurately measure and calculate the cross-section area of the upper airway. 2. mean areas of velopharyngeal and tongue-pharyngeal were significantly less than those in control subjects (all P < 0.05). OSAS patient's also showed relatively much larger collapsibility at sach site of the UA than controls. 3. At müller's maneuver, all the areas of OSAS patient's were below 40 mm2 and 60% cases appeared complete occlusion in pharyngeal. 4. All patient's had obstruction at velopharymx and airway collapses at multiple sites in 40% of cases. 5. At velopharyngeal the anatomical factors causing obstruction mainly were posterior displacement of soft palate, thicken and collapse of the pharyngeal wall. Besides the redundant lymph tissue at tongue base and posterior displacement of the tongue base, enlarged inferior pole of tonsil and collapse of pharyngeal wall played an important role at tongue-pharyngeal obstruction. 6. Diminished pharyngeal apertures and collapsibility were associated with increased rates of apnea and hypopnea index (P < 0.05). CONCLUSION: 1. CFPMM is able to measure and calculate UA's cross-section area and collapsibility, determine the site of obstruction, and helping the treatment. 2. Complete occlusion of UA at müller's maneuver is the criterion to determine site of UA obstruction in OSAS patient's during waking hours. 3. The anatomical abnormalities of UA of patients is reflects the severity of the OSAS.

Adult↗
PubMed2000

[Value of preservation of uvula in uvulopalatopharyngoplasty].

OBJECTIVE: To explore the effect of the modified Uvulopalatopharyngoplasty (UPPP) where uvula is preserved in the operation, and whether the postoperative complications are diminished. METHODS: Thirty consecutive patients with the obstructive sleep apnea syndrome (29 men, 1 woman) were analyzed by questionnaire, polysomnography and oral cavity measurement before and 6 months after uvulopalatopharyngoplasty to assess the surgical outcome and value of preservation of uvula in the operation. RESULTS: Eighty-seven percent of patients reported improvement of snoring and daytime sleepiness. Fifty-three percent of patients showed a decrease of at least 50% in the apnea and hypopnea indices. Among the mild and moderate obstructive sleep apnea (AHI < 50), 73.3% of them showed a decrease of at least 50% in the AHI. No velopalatal insufficiency occurred. The result of oral cavity measurement showed that the uvula, which was preserved completely during the operation, began to contract 2 weeks after the operation. Three to six month after operation, uvula contracted to the normal length and the anatomical shape of the pharyngeal cavity became normal. CONCLUSIONS: The results of the uvula preserving UPPP indicate that this approach not only improves the effect of the UPPP, but also avoids the postoperative complications. The uvula that preserved completely during the operation will contract to the normal length progressively.

Adult↗
PubMed2000

[The preparations and spectroscopic studies of infrared radiating materials].

ZrO2 and ZrO2-Al2O3 samples have been prepared by precipitation method, and characterized by FTIR, NIR FT-Raman, XRD and IR emission spectra, respectively. The result showed that these samples are the better infrared radiating materials, which have high efficiency and excellent properties. When compared with pure ointment, ZrO2-Al2O3 prepared has more strong infrared emission peaks. The application of infrared radiating materials in ointment may have a good effect on thermal infrared absorption vibration and absorption of medicine by sick part of body.

Aluminum Oxide↗
PubMed2000

[Vibrational frequencies study of the hydroxy-benzoquinones].

In this paper, we report the Ab initio calculation and experimental investigation of the vibrational frequencies of 4,5-dihydroxy-1,2-benzoquinone and 2,5-dihydroxy-1,4-benzoquinone. The main IR and Raman absorption bands of them have been assigned, learned from other strong points to offset one weakness, by combination the program Gaussian 94 and MOPAC. The difference in absorption bands between them has been discussed.

Benzoquinones↗
PubMed2000

[FTIR spectra of SO4(2-)/Fe2O3 nanosolid superacid].

The nanosolid superacid SO4(2-)/Fe2O3 was prepared by using nanometer chemical precursor FeO(OH)2 put in the SO4(2-) solution and dried. IR spectra of samples was determined with different calcination temperature, calcination time and with different concentration SO4(2-) solutions. They are different from IR of normal solid superacid. Then a good analysis and discussion are done.

English Abstract↗
PubMed1999

New approaches to understanding p53 gene tumor mutation spectra.

The first p53 gene mutation arising in a human tumor was described a decade ago by Baker et al. [S.J. Baker, E.R. Fearon, J.M. Nigro, S.R. Hamilton, A.C. Preisinger, J.M. Jessup, P. van Tuinen, D.H. Ledbetter, D.F. Barker, Y. Nakamura, R. White, B. Vogelstein, Chromosome 17 deletions and p53 gene mutations in colorectal carcinomas, Science 244 (1989) 217-221]. There are now over 10,000 mutations extracted from the published literature in the IARC database of human p53 tumor mutations [P. Hainaut, T. Hernandez, A. Robinson, P. Rodriguez-Tome, T. Flores, M. Hollstein, C.C. Harris, R. Montesano, IARC database of p53 gene mutations in human tumors and cell lines: updated compilation, revised formats and new visualization tools, Nucleic Acids Res. 26 (1998) 205-213; Version R3, January 1999]. A large and diverse collection of tumor mutations in cancer patients provides important information on the nature of environmental factors or biological processes that are important causes of human gene mutation, since xenobiotic mutagens as well as endogenous mechanisms of genetic change produce characteristic types of patterns in target DNA [J.H. Miller, Mutational specificity in bacteria, Annu. Rev. Genet. 17 (1983) 215-238; T. Lindahl, Instability and decay of the primary structure of DNA, Nature 362 (1993) 709-715; S.P. Hussain, C.C. Harris, Molecular epidemiology of human cancer: contribution of mutation spectra studies of tumor suppressor genes, Cancer Res. 58 (1998) 4023-4037; P. Hainaut, M. Hollstein, p53 and human cancer: the first ten thousand mutations, Adv. Cancer Res. 2000]. P53 gene mutations in cancers can be compared to point mutation spectra at the HPRT locus of human lymphocytes from patients or healthy individuals with known exposure histories, and accumulated data indicate that mutation patterns at the two loci share certain general features. Hypotheses regarding specific cancer risk factors can be tested by comparing p53 tumor mutations typical of a defined patient group against mutations generated experimentally in rodents or in prokaryotic and eukaryotic cells in vitro. Refinements of this approach to hypothesis testing are being explored that employ human p53 sequences introduced artificially into experimental organisms used in laboratory mutagenesis assays. P53-specific laboratory models, combined with DNA microchips designed for high through-put mutation screening promise to unmask information currently hidden in the compilation of human tumor p53 mutations.

Animals↗
PubMed1999

Expression and function of the gonadotropin-releasing hormone receptor are dependent on a conserved apolar amino acid in the third intracellular loop.

The coupling of agonist-activated heptahelical receptors to their cognate G proteins is often dependent on the amino-terminal region of the third intracellular loop. Like many G protein-coupled receptors, the gonadotropin-releasing hormone (GnRH) receptor contains an apolar amino acid in this region at a constant distance from conserved Pro and Tyr/Asn residues in the fifth transmembrane domain (TM V). An analysis of the role of this conserved residue (Leu(237)) in GnRH receptor function revealed that the binding affinities of the L237I and L237V mutant receptors were unchanged, but their abilities to mediate GnRH-induced inositol phosphate signaling, G protein coupling, and agonist-induced internalization were significantly impaired. Receptor expression at the cell surface was reduced by replacement of Leu(237) with Val, and abolished by replacement with Ala, Arg, or Asp residues. These results are consistent with molecular modeling of the TM V and VI regions of the GnRH receptor, which predicts that Leu(237) is caged by several apolar amino acids (Ile(233), Ile(234), and Val(240) in TM V, and Leu(262), Leu(265), and Val(269) in TM VI) to form a tight hydrophobic cluster. These findings indicate that the conserved apolar residue (Leu(237)) in the third intracellular loop is an important determinant of GnRH receptor expression and activation, and possibly that of other G protein-coupled receptors.

Amino Acid Sequence↗
PubMed1999

Structure/function studies of hepatocyte nuclear factor-1alpha, a diabetes-associated transcription factor.

Mutations in the transcription factor hepatocyte nuclear factor-1alpha (HNF-1alpha) cause maturity-onset diabetes of the young type 3 (MODY3), a form of diabetes mellitus characterized by autosomal dominant inheritance, early onset, and pancreatic beta-cell dysfunction. We have examined the effects of five diabetes-associated mutations (L12H, G191D, R263C, P379fsdelCT, and L584S585fsinsTC) on HNF-1alpha function including DNA binding ability, intracellular localization, and transactivation activity. L12H, P379fsdelCT, and L584S585fsinsTC mutations were found in patients with a clinical diagnosis of MODY, while G191D and R263C mutations were identified in patients diagnosed with type 2 diabetes. These mutations had diverse effects on the functional properties of HNF-1alpha. Comparison of the functional data with clinical information suggested that transactivation activity of mutant HNF-1alpha in beta cells like MIN6 may be the primary determinants of the phenotypic differences observed among diabetic patients with HNF-1alpha mutations.

Adolescent↗