Biomedical subjects

Y Luo

Publications and source records attributed to Y Luo.

At least 181 records · Page 10Linked to original sources

PubMed2000

[Immunotherapeutic effect of Mycobacterium vaccae on multi-drug resistant pulmonary tuberculosis].

OBJECTIVE: To evaluate the immuNotherapeutic effect of M. vaccae on multi-drug resistant (MDR) pulmonary tuberculosis. METHODS: 90 cases of MDR pulmonary tuberculosis with bacteriological positive were divided into immunotherapy (M, 28 cases), control (C, 28 cases) group at random pair and self control (S, 34 cases) group. The group M were treated by chemotherapy and M. vaccae for 6 months, the group C only treated by chemotherapy for 6 months, while group S only by chemotherapy in the first 3 months and in combination with M. vaccae in the next 6 months. RESULTS: After 6 months, the sputum negative conversion rates of group M were 43% in smear positive cases and 46% in culture positive cases, both of which were significant higher than those of group C (21%, 18%, P < 0.01). The sputum negative conversion rates of group S were 3%, 3% in smear and culture positive cases after 3-month chemotherapy, which increased to 44%, 41% respectively when M. vaccae was added for 6 months. Compared with group C, group M was better in improving of X-ray manifestation and cell-mediated immunity and closing of cavity (P < 0.05). The bacteriological relapse rates in group M, C, S were 8%, 20% and 7% respectively. CONCLUSION: As a adjunct to chemotherapy, M. vaccae is helpful for patients with MDR pulmonary tuberculosis by improving the cell-medicated immunity, sputum negative conversion and X-ray manifestation.

Adult↗

PubMed2000

[The role of Werner's syndrome gene in the genetic susceptibility to the type 2 diabetes in Chinese population].

OBJECTIVE: To test the hypothesis that Werner's syndrome gene (WRN) contributes to the genetic susceptibility to the type 2 diabetes in Chinese population. METHODS: Polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP) method was used to test the distribution of a polymorphism (Cys1367Arg ) of the WRN gene in 241 type 2 diabetes patients and 108 normal control subjects. RESULTS: The frequency of "R" allele of the WRN gene in type 2 diabetes patients whose diagnosis age >/= 45 was significantly increased as compared with that in the control subjects (9.6% vs 4.6%, P = 0.04). CONCLUSION: The high frequency of allele "R" of the WRN gene in early onset Chinese type 2 diabetes patients suggests that the WRN gene may contribute to the genetic susceptibility of type 2 diabetes in Chinese population through either directly causing diabetes or interacting with the diabetogenic gene.

Adult↗

PubMed2000

[Comparison of efficiency and merits of two parameters for bronchial challenge test by use of a simple equation].

The aim of this study was to investigate the relationship, merit and weakness of two parameters--the FEV1 and sGaw--for bronchial challenge test. The 36 cases of asthma patients were subjected to bronchial challenge test with FEV1 and sGaw as the test parameters simultaneously. A simple calculative equation was used. The Mch (challenge medicine) concentrations for a 20% decrease of FEV1(PC20FEV1) and for a 35% decrease of sGaw (PC35 sGaw) were figured out. The results showed that PC20 FEV1 and PC35 sGaw were 2.73 +/- 2.92 g/L and 1.50 +/- 2.03 g/L respectively. A significant difference between them was noted (P < 0.05), and their coefficient of correlation r = 0.738. The linear regression equation was PC35sGaw = 0.100 + 0.513 x PC20 FEV1. PC35sGaw was obviously lower than PC20 FEV1; the Mch amount for PC35sGaw was almost one half of that for PC20 FEV1, which indicated that sGaw was more sensitive than FEV1 as a parameter for bronchial challenge test. The FEV1, however, needs a relatively low standard of instrument, so it is more obtainable and popularized.

Adult↗

PubMed2000

[The measurement of tracheo-bronchial mucociliary clearance by technetium-99m DTPA aerosol scintigraphy].

Mucociliary clearance of respiratory channels is one of the important mechanisms guarding against retention of foreign particles within the lungs. Thus objective assay of the system is essential to recognizing and understanding its abnormalities. In this study, 18 healthy subjects and 32 patients with chronic obstructive pulmonary diseases (COPD) were examined by technetium-99m-DTPA aerosol scintigraphy. Monitoring was performed by visual inspection (cinescintigraphy) and quantitative analysis. The mucociliary clearance rates of 18 healthy subjects and 32 COPD patients were 3.89 +/- 0.92 mm/min and 1.32 +/- 0.59 mm/min respectively. Statistical analysis indicated that the airway clearance rate and mucociliary clearance rate of COPD patients were significantly lower than those of normal subjects (P < 0.01). The method of assay reported here is simple and objective. It has not only the advantage of visual inspection and quantitative analysis, but also the potential usefulness in studying other bronchial diseases and evaluating therapeutic effectiveness of drugs.

Adult↗

PubMed2000

[A study on the inactivation of p16 genes and the expression of P16 protein in primary hepatocellular carcinomas].

The aim of the present study was to determine whether p16 gene is involved in the genesis of primary hepatocellular carcinoma (HCC). Twenty-five primary HCC tumor and corresponding non-tumor liver tissue specimens were examined for P16 gene alterations. The identification of deletion of p16 gene exon 1 and exon 2 was performed using comparative multiplex polymerase chain reaction (PCR) analysis. The point mutation of p16 gene exon 2 was investigated by single strand conformational polymorphism(SSCP) analysis, and the status of p16 gene methylation was screened using PCR-based methylation analysis. Moreover, 35 parafin specimens of primary HCCs with corresponding non-tumor liver tissues, including the 25 cases described above for screening of p16 gene alterations, were investigated also for P16 protein expression by using immunohistochemical analysis. The results of comparative multiplex PCR analysis showed that 12% (3/25) p16 gene deletions, including homozygous deletions in 2 tumors and hemizygous deletion in 1 tumor, were found in the primary HCCs samples. No point mutation was identified in the remaining 22 tumor samples without p16 gene deletions by using SSCP analysis. Hypermethylation was detected in 24% (6/25) of tumor samples by PCR-based analysis. However the corresponding non-tumor liver tissue specimens were always unmethylated at p16 locus. Loss of P16 protein expression, detected by immunohistochemistry, occurred in 16 of 35 (45.7%) tumor samples, whereas all the non-tumor liver tissue specimens showed positive p16 staining. These results indicate that inactivation of p16 gene is relevant to the genesis of HCC.

Carcinoma, Hepatocellular↗

PubMed2000

[A study on the preservation of rat kidney with HX-III solution].

This study was conducted to compare the effects of HX-III solution and UW solution on rat kidney transplantation. Inbred Sprague-Dawley rats weighing 200-280 g, were used in allotransplantation. The donors and recipients were of the same sex. The rats were randomly divided into control (UW solution) and experimental (HX-III solution) groups, and each group included 48- and 72-hour preservation subgroups. There were ten rats in each subgroup. Kidneys were flushed with UW solution or HX-III solution and stored at 4 degrees C for 48 or 72 hours. Then, kidney allotransplantations were performed. The results showed that the rates of survival were 100% and 90% in UW group for 48- and 72-hour cold storage, but those in HX-III were 100% and 60%, respectively. With 48-hour preservation, the maximum serum creatinine levels in UW group were similar to those in HX-III group (P > 0.05). With 72-hour preservation, the maximum serum creatinine levels in UW group were lower than those in HX-III group (P < 0.05). On the 14th day posttransplantation, the histological findings on Kidneys in the two groups for 48-hour cold storage were almost the same, but the grafted kidneys in HX-III group were damaged more seriously than those in UW group for 72 hour cold storage. On the 28th day posttransplantation, the histological findings on the grafted kidneys were basically normal in all groups. The authors concluded that HX-III solution could preserve rat kidney for 48 hours effectively.

Animals↗

PubMed2000

[Image and quantity analysis of blood-gas in rabbit's artery and Na(+)-K(+)-ATPase in their lungs during PE-SWD treated by HFJV].

This study was made to gain an insight into the mechanism of high-frequency jet ventilation(HFJV) treatment for the pulmonary edema after seawater drowning(PE-SWD). PaO2, PaCO2 and oxygen saturation (SaO2) of the rabbit and Na(+)-K(+)-ATPase in the rabbit's lungs in three groups--PE-SWD group(PE-SWD-G), HFJV group (HFJV-G) and control group(CG), were measured and analysed by the blood-gas analyser and computer image system. The results showed that, after 100 minutes' HFJV, the PaO2, SaO2 and the activity of Na(+)-K(+)-ATPase in the lung capillary endothelial cells in HFJV-G were significantly higher than those in PE-SWD-G(P < 0.01 or P < 0.05). Three parameters of Na(+)-K(+)-TAPase(G1, D1 and D2) in HFJV-G almost returned to their values in CG. The authors suggest that the increase of PaO2 and SaO2 in the rabbit's artery blood in HFJV-G is closely related to the rehabilitation of Na(+)-K(+)-ATPase activity in the lungs after HFJV. The mechanism of successful HFJV treatment for PE-SWD is that HFJV can better correct hypoxemia and improve the rehabilitation of Na(+)-K(+)-ATPase activity in the rabbit's lungs.

Animals↗

PubMed2000

[Study on the mechanism of pulmonary edema after seawater drowning in rabbit].

To study the mechanism of pulmonary edema after seawater drowning (PE-SWD), the indexes of blood-gas and acid-base in rabbits artery blood were measured by the blood-gas analyser. The activity of Na(+)-K(+)-ATPase, cytochrome oxidase(CYTO) and alkaline phospharase(ALP) in the lungs were measured and analysed by computer image system. C-fos mRNA and Fos protein in the lungs were respectively determined by situ hybrioization and immunohisto chemical techniques. The distribution of phospholipid and Ca2+ of rabbits lungs was quantitatively analysed by ultrastructural location method. The results showed that, five parameters of PaO2, oxygen saturation(SaO2), pH, actual bicarbonite(AB) and base excess(BE) and the activity of Na(+)-K(+)-ATPase and CYTO decreased remarkably in PE-SWD. Both c-fos mRNA and Fos protein expression in pulmonary epithelial cells in PE-SWD were significantly elevated compared with the normal controls(P < 0.01). The phospholipids products in the pulmonary alveolar type II epithelial cells were decreased, however, the Ca2+ precipitate pellets inside the lung capillary endothelial cells and the pulmonary alveolar type I and II epithelial cells increased obviously. The arthors suggest that the injuny action of the seawater, hypoxia and metabolic acidosis may be the mian three mechanisms of the pulmonary edema induced seawater drowning. The lowering activity of Na(+)-K(+)-ATPase and CYTO in the lungs and calcium overload in the cells are not only evil consequence resulted from above three factors, but also the importent causes leading to the worse of PE-SWD. The transmiting line of Ca(2+)-fos may be also a key link to bring about the worse of PE-SWD.

Acidosis↗

PubMed2000

Vitro culture and immunohistochemical identification of astrocytes of infantile optic nerve.

OBJECTIVE: To culture astrocytes of optic nerve and to establish the cell lines for further study of healing process after optic nerve trauma. METHODS: Optic nerve astrocytes of infantile and adults with sudden death were cultured by tissue inoculation or tissue digestion with 0.25% Trypsin and 0.06% EDTA. The second and fourth passage cells were stained with HE and anti-GFAP, S-100 protein, Vimentin, and CD34 antibodies. RESULTS: The trypsinized astrocytes of infantile optic nerve reached confluence in 7 days, but the astrocytes of adults weren't successfully cultured. The cultured cells were in polygonal shape with processes; the cytoplasm was abundant and pink; the cells had light-blue nuclei. These cells were positive in GFAP, S-100 protein and vimentin staining, and negative in CD34 staining. CONCLUSIONS: The results showed that astrocytes of infantile optic nerve can be successfully cultured and trypsinization is a better method than tissue inoculation. The culture of infantile astrocytes is easier than that of adult astrocytes. Immunohistochemistry were used to determine the source and type of those cultured cells.

Adult↗

PubMed2000

[Culture and identification of human vascular endothelial cells].

PURPOSE: To investigate the culture technigue of human vascular endothelial cells in vitro and improve the success rate of culture. METHODS: Human vascular endothelial cells were isolated from umbilical cords by "Irrigative digestion" technique with 0.2% collagenase III and were digested by 0.0625% tripsin when the cells confluent. The cells were identified by morphologic and immunohistochemical assays. RESULTS: The cultured human umbilical vein endothelial cells attached completely after 24 hours in vitro, reached confluence in 3-5 days with the typical appearance of "stone of pave road" and were passaged on time; Immunohistochemically these cells were stained positively by CD34 monoclonal antibody. CONCLUSION: "Irrigative digestion" technique was a reliable method to obtain human umbilical vascular endothelial cells with high success rate. It can be widely used to the culture and researches of human vascular endothelial cells.

Antibodies, Monoclonal↗

PubMed2000

[Alternative splicing of de novo methyltransferase gene 3b in adult and newborn mice].

OBJECTIVE: To unravel the biological significance of the alternative splicing of de novo methyltransferase 3b, expression of the Dnmt3b gene in various tissues and developmental stages was investigated in postnatal mice. METHODS: RT-PCR and capillary electrophoresis were employed to analyze the alternative splicing pattern of Dnmt3b in tissues of newborn and adult mice. The results had been further reaffirmed by repeating and statistics analysis. Bioinformatics tools were used to predict the structure and hydrophobicity of the Dnmt3b exon10 coding sequence. RESULTS: Isoform with Dnmt3b exon10 was the abundant form in lung of newborn mice and in liver of both newborn and adult mice, while in other tissues of newborn and adult mice, the spliced isoform was presented as the predominant one. Peptide encoded by Dnmt3b exon10 was mainly random coil on the surface of Dnmt3b protein. CONCLUSIONS: The data demonstrate that the specific expression of Dnmt3b exists in tissues and developmental stages of postnatal mice. The alternative splicing of the exon 10 of Dnmt3b is possibly involved in the regulation of Dnmt3b's catalytic function. These results provide an insight into the developmental regulation and physiological function of the alternative splicing of the Dnmt3b gene.

Alternative Splicing↗

PubMed2000

[Changes of corneal endothelium in patients with primary glaucoma].

OBJECTIVE: To study the density and morphology of corneal endothelium in patients with primary glaucoma. METHODS: 125 eyes of 68 patients with glaucoma were compared with 63 eyes of 32 patients without glaucoma in the same age group. Exclusion criteria included history of corneal disease, ocular inflammation, trauma, contact lens wearing and surgery. The following date were recorded: type and duration of glaucoma, glaucoma medications, and intraocular pressure (IOP) measurement. Non-contact specular microscope was performed on the central cornea, endothelial images were analyzed by computer. RESULTS: Corneal endothelium density was significantly lower in patients with glaucoma[(2386.81 +/- 289.76)/mm2] than that in controls [(2540.78 +/- 195.66)/mm2]. Cell density of primary angle-closure glaucoma(PACG) [(2262.65 +/- 338.64)/mm2] was significantly low, especially in acute PACG[(1925.16 +/- 403.38)/mm2]. The area of endothelium became bigger than normal. But the endothelium density and morphology of primary open-angle glaucoma(POAG) and non-acute PACG had no changes. No correlation was found between mean recent IOP and endothelium density. CONCLUSIONS: This study suggested that patients with acute PACG might have lower corneal endothelium density and bigger cell area than those without glaucoma in the same age group. The endothelium density and morphology of POAG and non-acute PACG were as similar as those of normal persons.

Adult↗

PubMed2000

[Inspection of writing-time and script by FTIR microscope].

The IR spectra of different ball-pen script at different paper were determined by FTIR microscope and ATR objective. The spectra of different script on different paper in no time and in three-month time are compared. The result is showed that the most of IR spectra of different ball-pen are different and the IR spectra got in no time and in three-month time are different. The FTIR spectra can be used for inspecting scripts and help to inspect the writing-time.

Forensic Medicine↗

PubMed1999

Dopamine stimulates redox-tyrosine kinase signaling and p38 MAPK in activation of astrocytic C6-D2L cells.

An increase in dopamine (DA) availability in rat brain has been suggested to participate in certain neurodegenerative processes. However, the regulatory effects of DA on glial cells have not been extensively studied. Using a rat C6 glioma cell line stably expressing recombinant D2L receptors, we have found that micromolar levels of DA stimulate mitogenesis and glial fibrillary acidic protein (GFAP) expression, both serving as parameters of reactive gliosis. This mitogenesis occurs about 29 h after exposure to DA and requires D2-receptor-mediated intracellular redox-tyrosine kinase activation. Either DA or quinpirole, a D2 receptor agonist, stimulates protein tyrosine phosphorylation. Application of either DPI, a potent inhibitor of NADPH-dependent oxidase, or NAC, an anti-oxidant, effectively prevented DA-induced tyrosine phosphorylation and DNA synthesis. Preincubation of (+)-butaclamol, a D2 receptor antagonist, inhibits both DA-stimulated tyrosine phosphorylation and mitogenesis. DA at micromolar levels also stimulates GFAP expression. This DA-regulated GFAP expression can be completely inhibited by SB203580, a selective p38 MAPK inhibitor, but not influenced by (+)-butaclamol and genistein, a protein tyrosine kinase inhibitor. Thus, our data suggest that regulation of DNA synthesis and GFAP expression induced by DA is mediated by independent signaling pathways. The mitogenesis requires a D2-receptor-mediated protein tyrosine kinase cascade, while GFAP expression needs a D2-receptor-independent p38 MAPK activation. This observation may help to understand the processes of reactive gliosis in some dopaminergic-related neurodegenerative diseases.

Animals↗

PubMed1999

TNIK, a novel member of the germinal center kinase family that activates the c-Jun N-terminal kinase pathway and regulates the cytoskeleton.

Germinal center kinases (GCKs) compose a subgroup of the Ste20 family of kinases. Here we describe the cloning and characterization of a novel GCK family kinase, Traf2- and Nck-interacting kinase (TNIK) that interacts with both Traf2 and Nck. TNIK encodes a polypeptide of 1360 amino acids with eight spliced isoforms. It has 90% amino acid identity to the Nck-interacting kinase in both the N-terminal kinase domain and the C-terminal germinal center kinase homology region. The homology drops to 53% in the intermediate region. TNIK specifically activates the c-Jun N-terminal kinase pathway when transfected into Phoenix-A cells (derivatives of 293 cells), similar to many GCKs. However, in contrast to other GCKs, this activation is mediated solely by the GCK homology region of TNIK. In addition, in Phoenix-A, NIH-3T3, and Hela cells, overexpression of wild type TNIK, but not the kinase mutant form of TNIK, results in the disruption of F-actin structure and the inhibition of cell spreading. Furthermore, TNIK can phosphorylate Gelsolin in vitro. This is the first time that a GCK family kinase is shown to be potentially involved in the regulation of cytoskeleton.

3T3 Cells↗

PubMed1999

Beta-secretase cleavage of Alzheimer's amyloid precursor protein by the transmembrane aspartic protease BACE.

Cerebral deposition of amyloid beta peptide (Abeta) is an early and critical feature of Alzheimer's disease. Abeta generation depends on proteolytic cleavage of the amyloid precursor protein (APP) by two unknown proteases: beta-secretase and gamma-secretase. These proteases are prime therapeutic targets. A transmembrane aspartic protease with all the known characteristics of beta-secretase was cloned and characterized. Overexpression of this protease, termed BACE (for beta-site APP-cleaving enzyme) increased the amount of beta-secretase cleavage products, and these were cleaved exactly and only at known beta-secretase positions. Antisense inhibition of endogenous BACE messenger RNA decreased the amount of beta-secretase cleavage products, and purified BACE protein cleaved APP-derived substrates with the same sequence specificity as beta-secretase. Finally, the expression pattern and subcellular localization of BACE were consistent with that expected for beta-secretase. Future development of BACE inhibitors may prove beneficial for the treatment of Alzheimer's disease.

Alzheimer Disease↗

PubMed1999

Role of IL-12 in the induction and potentiation of IFN-gamma in response to bacillus Calmette-Guérin.

Although Mycobacterium bovis bacillus Calmette-Guérin (BCG) has been accepted as the most effective agent in clinical use against superficial bladder cancer, its mechanism of action remains incompletely understood. A kinetic analysis in assessing the potential role of cytokines from BCG-stimulated murine splenocytes showed that IL-12 expression preceded that of other cytokines. Experiments subtracting endogenous BCG-driven IL-12 using neutralizing Ab or augmenting its activity with supplemental rIL-12 revealed not only that IL-12 plays a dominant role in IFN-gamma induction but also that it is normally dose limiting. A striking increase in IFN-gamma production could be generated in both mouse and human immunocompetent cell culture by the addition of even a small amount of rIL-12. Moreover, this same synergistic effect could be replicated during in vivo administration of BCG plus rIL-12 into the mouse bladder and was observed in a patient receiving intravesical combination therapy. In costimulation cultures, this synergy appeared to partially rely on IL-18 and IL-2 and could be down-regulated by IL-10. This suggests that a dynamic interplay between Th1 and Th2 cytokines is responsible for net IFN-gamma production. The ability of supplemental exogenous IL-12 to strongly shift this balance toward Th1 provides an immunological basis for using it in conjunction with intravesical BCG for bladder cancer immunotherapy.

Adjuvants, Immunologic↗

PubMed1999

Chemokine amplification in mesangial cells.

Mesangial cells are specialized cells of the renal glomerulus that share some properties of vascular smooth muscle cells and macrophages. They are implicated in the pathogenesis of many forms of nephritis. The murine CXC-chemokines macrophage inflammatory protein-2 (MIP-2) and KC induce migration of mouse mesangial cells. Mesangial cells also exhibit a unique chemokine feedback mechanism. Treatment with nanomolar concentrations of MIP-2 or KC markedly up-regulates monocyte chemoattractant protein-1 and RANTES expression in mesangial cells. Autoinduction of MIP-2 and KC mRNA was also noted. Low levels of MIP-1alpha, MIP-1beta, and IFN-gamma-inducible protein-10 were induced following treatment with higher doses of MIP-2 or KC. These effects are specific to mesangial cells, as MIP-2 or KC treatment of renal cortical epithelial cells or peritoneal macrophages failed to induce chemokine production. This cascade of chemokine interactions may contribute to renal infiltration and leukocyte activation. The abilities of MIP-2 or KC to stimulate their own synthesis may also contribute to the maintenance and chronic course of glomerular inflammation. The mesangial cell receptor for MIP-2 and/or KC is unknown but is not CXC-chemokine receptor-2.

Animals↗