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Y Luo

Publications and source records attributed to Y Luo.

At least 109 records · Page 6Linked to original sources
PubMed2001

N-cadherin and Cx43alpha1 gap junctions modulates mouse neural crest cell motility via distinct pathways.

Our previous studies showed an essential role for connexin 43 or alpha1 connexin (Cx43alpha1) gap junctions in the modulation of neural crest cell motility. Cx43alpha1 gap junctions and N-cadherin containing adherens junctions are expressed in migrating cardiac neural crest cells. Analysis of the N-cadherin knockout (KO) mouse model revealed that N-cadherin is essential for gap junction mediated dye coupling but not for expression of Cx43alpha1 gap junctions in neural crest cells. Time lapse videomicroscopy and motion analysis showed that the motility of N-cadherin KO neural crest cells were altered, but the motility changes differed compared to Cx43alpha1 KO neural crest cells. These observations suggest that the role of N-cadherin in cell motility is not simply mediated via the modulation of Cx43alpha1 mediated cell-cell communication. This was confirmed by a parallel analysis of wnt-1 deficient neural crest cells, which also showed a reduction in dye coupling, and yet no change in cell motility. Analysis of p120 catenin (p120ctn), an Amardillo family protein known to play a role in cell motility, showed that it is colocalized with N-cadherin and Cx43alpha1 in migrating neural crest cells. This subcellular distribution was altered in the N-cadherin and Cx43alpha1 KO neural crest cells. Given these results, we propose that N-cadherin and Cx43alpha1 may modulate neural crest cell motility by engaging in a dynamic cross-talk with the cell's locomotory apparatus through p120ctn signaling.

Animals↗
PubMed2001

TECA hybrid artificial liver support system in treatment of acute liver failure.

AIM: To assess the efficacy and safety of TECA type hybrid artificial liver support system (TECA-HALSS) in providing liver function of detoxification, metabolism and physiology by treating the patients with acute liver failure (ALF). METHODS: The porcine liver cells (1-2) x 10(10) were separated from the Chinese small swine and cultured in the bioreactor of TECA-BALSS at 37.0 degrees C and circulated through the outer space of the hollow fiber tubes in BALSS. The six liver failure patients with various degree of hepatic coma were treated by TECA-HALSS and with conventional medicines. The venous plasma of the patients was separated by a plasma separator and treated by charcoal adsorbent or plasma exchange. The plasma circulated through the inner space of the hollow fiber tubes of BALSS and mixed with the patients' blood cells and flew back to their blood circulation. Some small molecular weight substances were exchanged between the plasma and porcine liver cells. Each treatment lasted 6.0-7.0 h. Physiological and biochemical parameters were measured before,during and after the treatment. RESULTS: The average of porcine liver cells was (1.0-3.0) x 10(10) obtained from each swine liver using our modified enzymatic digestion method. The survival rate of the cells was 85%-93% by trypan blue stain and AO/PI fluorescent stain. After cultured in TECA-BALSS bioreactor for 6 h, the survival rate of cells still remained 70%-85%. At the end of TECA-HALSS treatment, the levels of plasma NH(3), ALT, TB and DB were significantly decreased. The patients who were in the state of drowsiness or coma before the treatment improved their appetite significantly and regained consciousness, some patients resumed light physical work on a short period after the treatment. One to two days after the treatment, the ratio of PTA increased warkedly. During the treatment, the heart rates, blood pressure, respiration condition and serum electrolytes (K(+), Na(+) and Cl(-)) were stable without thrombosis and bleeding in all the six patients. CONCLUSION: TECA-HALSS treatment could be a rapid, safe and efficacious method to provide temporary liver support for patients with ALF.

Acute Disease↗
PubMed2001

Identification and characterization of a novel OCA-B isoform. implications for a role in B cell signaling pathways.

OCA-B is a B lymphocyte-specific transcription coactivator that mediates tissue- and stage-restricted transcription of immunoglobulin genes. Earlier genetic studies revealed that OCA-B is essential for germinal center formation and production of secondary immunoglobulin isotypes. Biochemically purified OCA-B contains p35 and p34 isoforms, and a further analysis has now revealed that p35 is derived from a newly found isoform, p40. More importantly, it has been found that p35 is myristoylated in vivo and that this leads to dramatic changes (including localization to membrane compartments) in its properties. These results suggest that the p35 isoform of OCA-B has functions distinct from those of the nuclear p34 and that it might be a component of a signaling pathway that is required for late-stage B cell development.

3T3 Cells↗
PubMed2001

[Study on the quantitative structure toxicity relations of chlorophenols in some aquatic species].

The quantitative structure-activity relations between electronic structure of chlorophenols and their toxicity to Bluegill and Guppy were were studied. The electronic structure parameters of fourteen chlorophenols were calculated by using CNDO/2 method. The quantitative structure-activity relationships between electronic structure parameter of chlorophenols and their toxicity to Bluegill and Guppy were were discussed respectively by step regression analysis. Two linear equations were obtained as follows: (1) for Bluegill, LC50 = -122.493 + 20.334 sigma Q pi R; (2) for Guppy DLC50 = -100.263 + 16.639 sigma Q pi R. The results showed that the toxicity of chlorophenols to Bluegill and Guppy were increased as the sum of pi-charge (sigma Q pi R) at the carbon atom on benzene ring increased.

Animals↗
PubMed2001

[Influence of electroporation on the biological activities of primary rat hepatocytes].

OBJECTIVE: To investigate the influence of electroporation on the biological activities of primary rat hepatocyte and to optimize the electroporation conditions introducing foreign genes into hepatocytes. METHODS: A single-pulse procedure was performed at low voltage (220-400 V) but high capacitance (500-950 microF). Its influence on hepatocyte activities was detected by Trypan blue exclusion (TBE) and MTT analysis. Besides, ALB, ALT and LDH in the supernatants of hepatocytes were tested by biochemical assay. RESULTS: Little hepatocyte damage and high survival rate (>90%) was found from 36 hours till 9th day of culture. At 36th hour after electroporation, ALB, ALT and LDH in the supernatants of Group B (220V, 950 microF) and C (400 V, 950 microF) were higher than those of control group. Whereas TBE and MTT analysis failed to indicate the significant difference of cell viability between electroporation groups and control group. CONCLUSIONS: This electroporation procedure is one of the optimal choices to introduce foreign genes into primary rat hepatocytes.

Animals↗
PubMed2001

[The technical method for noninvasive magnetic stimulation of nerve center and its clinical application].

The increasing use of non-invasive magnetic stimulation technique for nerve center function examination and functional neuromuscular rehabilitation is a new cynosure in biomedical engineering and neuro-electrophysiologic researches. This paper analyzes theoretically the magnetic stimulation of first demonstration extending the technique model to human body, and the magnetic principle of physics. The characteristics of magnetic stimulation can be highlighted by comparing it to conventional electrical stimulation. Also presented are the peripheral multichannel magnetic stimulation to mimic electrical stimulation and the clinical functions toward neuromuscular rehabilitation.

Central Nervous System↗
PubMed2001

Aortic and mitral valve replacement with retrograde perfusion in the beating heart.

OBJECTIVE: To estimate the value of aortic valves and combined mitral valve replacement with retrograde perfusion in beating hearts. METHODS: Continuous retrograde coronary sinus perfusion with beating hearts was used in 83 patients undergoing aortic valve or aortic valve combined with mitral valve replacement, without application of cardioplegia. After aortic valve replacement, the retrograde perfusion was changed to antegrade perfusion for mitral valve replacement or correction of the other deformities (group A). Cold blood cardioplegia solution (15 degrees C) was infused at intervals in 20 cases (group B). The following parameters were tested: lactate, ET, CTn-T and MDA in blood; myocardial ultra-structure; and cardiac rhythm and cardiac output (CO). RESULTS: All biochemical values increased after cardiopulmonary bypass (P < 0.05-0.01). Empty and beating heart sinus rhythm was maintained in group A. Myocardial ultrastructure did not change significantly. The pump was stopped smoothly as the surgical procedure finished. No postoperative low cardiac output syndrome or arrhythmia was observed. Eight-one patients recovered smoothly, two died from renal failure or infective shock. When the pump stopped, all patients in group B were supported by 5-10 micrograms.kg-1.min-1 dopamine. Transient pacing was used in 9 patients. One patient died from low cardiac output syndrome. CONCLUSION: This method is a good myocardial protection which simulates physiologic status. It is applicable to aortic valve and combined mitral valve replacement of patients with large heart or heart failure and long time aortic cross-clamping. Ideal clinical effect can be achieved.

Adolescent↗
PubMed2001

[Morphology of abdominal aortic aneurysm and its clinical importance].

OBJECTIVE: To investigate the morphology of abdominal aortic aneurysms(AAA) and anatomical importance in endovascular surgery. METHODS: The images of AAA were measured by spiral CT angiography in 30 patients from January 1998 to December 2000. RESULTS: The mean diameter of AAA was 5.9 cm (range: 4.0-12.2). The diameter of AAA was positively correlated with neck angle (r = 0.47, P < 0.05) and negatively correlated with neck length(r = -0.41, P < 0.05). Twelve patients(40%) were anatomically feasible for endovascular repair (EVR); 18 patients were excluded for EVR due to angulated proximal necks (mean 88.8 degrees, range 70 degrees-110 degrees) (16 patients; 53.3%), short neck (1; 3.3%), and unilateral common iliac artery occlusion with thrombosis in neck (1; 3.3%). CONCLUSION: The angulated neck was a major single factor for excluding Chinese patients from EVR.

Adult↗
PubMed2001

[Chelate-induced phytoextraction of copper contaminated upland red soil].

A copper spiked red soil was used in pot experiment to study the effects of EDTA and low molecule weight organic acids on Cu speciation in soil, and Cu uptake by Brassica juncea. The results showed that the mobility of Cu in soil was improved obviously when EDTA was added at the vigorous growth stage. Both water-extractable and exchangeable Cu concentration increased significantly following EDTA addition. Citric acid and malic acid only had an effect on water-extractable Cu, and no effect on Cu uptake by the plant. EDTA significantly increased the concentration of Cu in plant leaves and roots, and the Cu uptake by Brassica juncea. All of these indicated the chelate-induced phytoextraction.

Absorption↗
PubMed2001

[Optimization of synthetic culture condition on lignin biodegradation ability of alkaliphilic ligninolytic bacteria using orthogonal experimental design].

The effects of seven single culture factors on lignin biodegradation ability of alkaliphilic ligninolytic bacteria strain 6 in alkaline liquid medium (pH approximately 10.5) with compounded carbons were optimized using orthogonal experiments. The result showed the seven single culture factors promote the activities of Laccase and MnP and the degradation rate of wheat straw lignin in varying degrees. The synthetic result was analysised. The optimal synthetic condition was static culture (10 days culture period), 37 degrees C, the initial pH10.6, 1 g/L sugar (the starting carbons), wheat straw lignin (the second carbons, wheat straw powder 20 g/L, added into on the fourth day after inoculation), 1.2 g/L NH4NO3 (nitrogen), 0.3% detergent T-80, 70 ml medium/250 ml flask.

Bacteria↗
PubMed2001

[Clinical application of ultrasonographic indexes for assessment of amniotic fluid volume].

OBJECTIVE: To find the favorable interval of assessment of amniotic fluid volume and the optimal standard for oligohydramnios. METHODS: To determine actual amniotic fluid volume (AAFV) by collecting amniotic fluid during cesarean section and compare it with maximum vertical pocket (MVP) and amniotic fluid index (AFI) in different interval between cesarean section and measurement and test the sensitivity and specificity of MVP and AFI of different standard. RESULTS: The ultrasonographic results were divided into three groups according to the interval between measurement and delivery: within 24 hours group, 24-96 hours group and longer than 96 over hours group. The results of the within 24 hours and 24-96 hours groups were positively correlated with AAFV, while the results of the group longer than 96 hours were not statistically significant. The correlation coefficients were 0.840 and 0.869 for MVP, 0.789 and 0.874 for AFI respectively. The receiver-operator characteristic curve showed that MVP < 4 cm and AFI < 10 cm were superior to any other standards to scan oligohydramnios. The sensitivity of these standards was 0.76 and 0.61, and the specificity was 0.83 and 0.91. CONCLUSION: It is highly recommended to estimate the amniotic fluid of high risk pregnant women, women with MVP < 4 cm or AFI < 10 cm and with a pregnancy week > 40 weeks should be monitered by ultrasonography every four days.

Amniotic Fluid↗
PubMed2001

[Microscopic identification of Rhodiola henryi].

OBJECTIVE: To study the microscipic characteristics of the rhizoma, root, stem, leaf and powder of Rhodiola henryi. METHOD: By microscopic observation. RESULTS: The brown substance was always found in the rhizoma and root of Rhodiola henryi. There was a fiber ring in the cambium region of the stem, and some fiber bundles surrounded the pholem. The epidemis cells of the leaf were different in size, and some were very large. Most stomata were anisocytic. The pollen grains were spherical or oblate, with irregularly reticular veins on the outer walls and three germ pore furrows. CONCLUSION: The above-mentioned characteristics provided a basis for the identification of Rhodiola henryi.

Microscopy↗
PubMed2001

[The immunotherapeutic effect of Mycobacterium vaccae vaccine on initially treated pulmonary tuberculosis].

OBJECTIVE: To evaluate the effect and safety of Mycobacterium vaccae vaccine (M. vaccae vaccine) on initially treated pulmonary tuberculosis. METHODS: 342 cases of initially treated pulmonary tuberculosis with smear and culture positive were divided into immunotherapy (M, 171 cases) group and control (C, 171 cases) group at random pair. The group M were treated by chemotherapy with a regimen of 2HRZE/2HR and immunotherapy with M. vaccae vaccine for 6 months. The group C were treated only by chemotherapy with a regimen of 2HRZE/4HR. RESULTS: The sputum smear-negative conversion rates in group M 1, 2 and 6 months after treatment were 36.8%, 80.1% and 98.2% respectively; those in group C were 19.9%, 54.4% and 98.8% respectively. The sputum culture-negative conversion rates in group M 1, 2 and 6 months after treatment were 47.4%, 85.9% and 99.4% respectively; those in group C were 19.3%, 67.8% and 98.8% respectively. The sputum-negative conversion rates of group M were significantly higher than those of group C after 1 and 2 months treatment (P < 0.01), but there were no statistically significant differences between the two groups at the end of 6 months after treatment (P > 0.05). Compared with group C, group M were better in improving of X-ray manifestation, increasing of the percentage of CD(3) and CD(4) T cell and the ratio CD(4)/CD(8) and closing of cavity (P < 0.01). The side effects of M. vaccae vaccine were rare and slight. The bacteriological relapse rates in group M, C were 3.0%, 5.6% respectively (P > 0.05). CONCLUSIONS: As an adjunct to chemotherapy, immunotherapy with M. vaccae vaccine is helpful for patient with initially treated pulmonary tuberculosis, and it is possible to further shorten the duration of short-course chemotherapy with a combination of chemotherapy and M. vaccae vaccine.

Adolescent↗
PubMed2001

[Role of salbutamol in inducing apoptosis of cultured human airway smooth muscle cells].

OBJECTIVE: To study the effect of salbutamol on inducing apoptosis of cultured human airway smooth muscle cells (ASMCs). METHODS: Human ASMCs were isolated and cultured in DMEM containing 10% fetal bovine serum. Cells of Passes 4 approximately 6 were used in experiments. The cells were cultured with salbutamol, cromakalim, 8-Br-cAMP for 24 or 48 hours. Morphological changes were observed by light microscopy and electron microscopy. DNA fragmentation was analyzed by agarose gels. SP immunohistological staining method was performed to detect the changes of expressions of p53, Bcl-2 and Bax gene. The percentage of apoptosis cell was detected by situ end labeling technique (TUNEL) of fragmental DNA. RESULTS: (1) Salbutamol or 8-Br-cAMP decreased the number of viable cells. At 48 hour, at 300 micromol/L, number of viable cells was the lowest. (2) Human ASMCs incubated with salbutamol (100 micromol/L or 300 micromol/L) for 48 h revealed morphological features of apoptosis (cellular shrinkage, condensation of chromatin). (3) Agarose gel electrophoresis showed a characteristic "ladder" of DNA bands representing integer multiples of the internucleosomal DNA length (about 180 approximately 200 bp). (4) The expression of p53 or Bax gene in salbutamol or 8-Br- cAMP group was significantly higher than that in control group, but the expression of BCl-2 gene was lower than that in control group. (5) The TUNEL indicated: apoptotic positive rate of human ASMCs was significantly different following 100 micromol, 300 micromol salbutamol or 100 micromol 8-Br-cAMP treatment (q = 24.04, 58.47, 27.78 respectively, P < 0.0001), but cromakalim, propranolol before salbutamol not affected basal level of apoptotic cell (q = 0.12, 0.52 respectively, P = 0.932, 0.717 respectively), as compared with the controls. CONCLUSIONS: (1) Salbutamol induced apoptosis in human ASMCs in vitro in time and concentration dependent manner. (2) A cAMP-protein kinase A pathway is necessary and sufficient for salbutamol induced apoptosis. (3) beta(2) adrenergic agonist or cAMP analogue may prevent airway remodeling in asthma.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed2001

[Culture and identification of fetal human retinal photoreceptors].

OBJECTIVE: To investigate the methods of isolation and culture of fetal human retinal photoreceptors. METHODS: Fetal human retinal photoreceptors were obtained by enzyme gradation digestion, cultured in media conditioned by retinal pigment epithelial cells (RPE-CM), identified by morphologic observation and immunohistochemically stained with rod specific opsin 4D2 (Rho 4D2) antibody. The digested retinal tissues were tested by hematoxylin-eosin (HE) staining. RESULTS: Enzyme gradation digestion could obtain relatively pure retinal photoreceptors. These cells were stained positively for Rho 4D2 antibody, and survived in RPE-CM for a long time. CONCLUSION: Fetal human retinal photoreceptors obtained by enzyme gradation digestion can survive in RPE-CM for a long time and express rod specific opsin. This culture system will provide a source for human retinal photoreceptor transplantation and further studies of photoreceptors in vitro.

Cell Division↗
PubMed2001

[Study on the association of pathologic myopia with HLA-DQB1 gene].

OBJECTIVE: To investigate the association of pathologic myopia (PM) with HLA-DQB1 alleles in order to study the pathogenesis of PM. METHODS: The genome DNA of 66 patients with PM was extracted from the blood. The second exon of the HLA-DQB1 gene was amplified by polymerase chain reaction (PCR), and individual PCR products were digested by allele specific restriction enzymes of Hae III, BssH II, Apa I, BsaH I, Hae II, Hpa II, Rsa I, Bsp 1286 I for typing. Genotype was determined by restriction fragment length polymorphism (RFLP) pattern. The frequency of 16 alleles of HLA-DQB1 was detected and compared with that of the healthy control. RESULTS: The frequencies of HLA-DQB1 * 0301 and * 0303 were significantly higher in the patients with PM (P < 0.0001), while that of HLA-DQB1 * 0601 and * 0602 were significantly lower (P < 0.0001) than that of the control group. CONCLUSION: HLA-DQB1 * 0301, * 0303 alleles are susceptible alleles, and possibly they are the pathogenic genes, * 0601, * 0602 are resistant alleles, and may be they possess the protective property.

Adolescent↗
PubMed2001

[Detection of the expression of Smad4, transforming growth factor beta(1) and beta receptor II proteins in paraffin-embedded human pancreatic cancer tissues].

OBJECTIVE: To explore the relationships between Smad4, TGF beta1 and TbetaR II in the TGF-beta pathway and the possible mechanisms by which they effect pancreatic carcinoma. METHODS: The expression of Smad4, TGF beta1 and TbetaR II in paraffin embedded pancreatic carcinoma tissues was detected by using antibodies against Smad4, TGF beta1 and TbetaR II with EnVision immunohistochemistry. RESULTS: The positive rates of Smad4, TGF beta1 and TbetaR II were 58.93% (33), 66.07% (37) and 60.71% (34), respectively. The positive rates of the above three proteins in matched normal pancreatic tissues were 89.29% (50), 25.00% (14) and 25.00% (14) respectively. There was a significant relationship between the expression of TGF beta1, clinical stage and the metastasis of the tumor (P < 0.05). There was also a significant relationship between the expressions of TGF beta1 and TbetaR II (P < 0.05). CONCLUSIONS: The expression of Smad4 in pancreatic carcinoma tissue is significantly decreased but the expression of TGF beta1 and TbetaR II are increased. Smad4 may play an important role in the regulation of TGFbeta inducible gene expression and subsequent growth inhibition, but TGFbeta may also act in a Smad4-independent manner.

DNA-Binding Proteins↗