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Biomedical subjects

Z Yang

Publications and source records attributed to Z Yang.

At least 325 records · Page 18Linked to original sources
PubMed2000

[Construction of membrane-anchored interleukin-6 receptor beta subunit mutant and its effect on IL-6 signal transduction].

OBJECTIVE: To investigate whether the membrane-anchored gp130 mutant containing the second and the third fibronectin type III modules of the extracellular region could still transduce IL-6 signal. METHOD: The membrane-anchored gp130 mutant cDNA was amplified by the overlap extension PCR and inserted into the mammalian expression vector pRc/RSV. The mutant was proved to be effectively expressed in SKO-007 cells and Jurkat cells by dot blot hybridization. The mutant's effects on IL-6 signaling in these two kinds of cells were detected by electrophoresis mobility shift assay (EMSA). RESULTS: In SKO-007 cells, the mutant could enhance the activated APRF, but the effect was not as strong as that of wide-type gp130. IL-6 could not activate nuclear factors in Jurkat cells. After the expression vectors pRc/RSVgp130 and pRc/RSV were transfected into Jurkat cells, IL-6 could activate APRF, but could not do NF-IL6. Similar to the results in SKO-007 cells, the effects of the mutant was also weaker than that of wild-type gp130. CONCLUSION: Although the mutant could still transduce IL-6 signal, it is not as efficiently as the wild-type gp130. It suggested that the Ig-like domain of gp130 also played an important role in IL-6 signal transduction.

Antigens, CD↗
PubMed2000

[Sulindac induced apoptosis of HT-29 colon adenocarcinoma cell].

This study was intended to examine whether sulindac induces apoptosis in the HT-29 cells. Flow cytometry, transmission electron microscopy and DNA electrophoresis were used. Flow cytometry, transmission electron microscopy and DNA electrophoresis all demonstrated that sulindac could induce apoptosis of the HT-29 cell line in a time- and dose-dependent manner. After treatment with 0.3 mmol/L, 0.6 mmol/L and 1.2 mmol/L sulindac for 48 hours, apoptotic cells in the treatment groups reached 5.8%, 7.6% and 11.7% versus 2.9% in the control group; after treatment for 72 hours, apoptotic cells in the treatment groups increased to 12.5%, 15.4% and 24.4% versus 5.1% in the control group, respectively, P < 0.05. This study has demonstrated that colon adenocarcinoma HT-29 cell line can be induced by sulindac.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

[Effects of pinyangmycin, dexamethasone and sodium morrhuate injection on treatment of cavernous hemangioma in maxillofacial regions].

OBJECTIVE: To evaluate the effects of Pinyangmycin, Dexamethasonum and Sodium morrhuate injected homochronouly on treatment of cavernous hemangioma in maxillofacial regions. METHODS: The medical records of 115 patients with cavernous hemangioma in maxillofacial regions between September, 1996 and September, 1998 were reviewed. Fifty of the patients were men, and 65 were women, with a ratio of 1:1.3. The age of the patients was from 4 months old to 45 years old. 73 of the hemangioma bodies were sited in maxillofacial regions, 42 were sited in oral cavity. The sizes of the lesions varied from 1 cm x 1 cm to 5 cm x 8 cm. Treatment procedure: 1. Preparation: 8 mg Pinyangmycin was dissolved in 5 mg/ml Dexamethasonum and in 4 ml of 1% procain which were ready for use; 2. Injection: 1-5 ml (Pinyangmycin 1.6-8.0 mg) of mixed solution was first injected to the hemangioma, then followed by an injection of 0.5-2.0 ml Sodium morrhuate according to local appearance, size of the tumor and patient's age. Generally, the amount of each injection should not be over 8 mg Pinyangmycin. If the tumor did not subside after an injection, another injection might be repeated every 5-7 days, and this process might be repeated 3-5 times. The total dose of Pinyangmycin should not be over 40 mg. RESULTS: 115 patients were followed up for 6-24 months. 81 of 115 (70.43%) cases were recovered, and 30 (26.09%) cases were basically recovered. 4 (3.48%) cases got improvement. The recovery rate were 96.52%, and the total efficiency was 100%. CONCLUSION: This method may be a safe, simple and effective therapy to cavernous hemangioma in maxillofacial regions.

Adolescent↗
PubMed2000

[The modulation of type I collagen and its receptor system on biological characteristics of osteoblasts].

This paper addresses the question whether type I collagen-receptor system is necessary for the functional activity of osteoblasts. Through blocking type I collagen-receptor system by type I collagen antibody or integrin alpha 2 beta 1 antibody, the proliferation of osteoblasts was studied by cell count, the apoptosis was studied by flow cytometry, and the mRNA expressions of type I collagen, integrin alpha 2 beta 1 and osteocalcin were also detected by RT-PCR techniques. When type I collagen-receptor system was blocked, osteoblasts showed high apoptosis rate, lower growth kinetics and weak mRNA expression of type I collagen, integrin alpha 2 beta 1 and osteocalcin; the blocking effect was reversible. It suggests that type I collagen-receptor system is necessary for osteoblastic phenotype. The biomaterials for bone tissue engineering should be constructed according to the extracellular matrix of osteoblasts, which supply normal extracellular environment for osteoblasts.

Apoptosis↗
PubMed2000

Preliminary study on in vitro induced differentiation of embryonic stem cells into neurons.

PURPOSE: To study preliminarily in vitro induced differentiation of embryonic stem cells into neurons for further investigation of an alternative for the treatment of glaumatous neuropathy. MATERIALS AND METHODS: Supernatant of cultured Buffalo rat liver cells (buffalorat liver cell-conditioned medium, BRL-CM) was used for culturing embryonic stem cells (ES-D3 cell line). Morphological features of undifferentiated ES cells were studied by HE staining and electron microscopy. Based on the methods used by Bain et al, we modified the methods and used retinoic acid (RA) as an inducer to differentiate ES-D3 cells and cytosine arabinoside (Ara-C) as inhibitor of proliferative cells. The growth of the cells was observed under phase contrast microscope. RESULTS: ES-D3 cells cultured by BRL-CM grew in aggregates and remained undifferentiated. Electromicroscopy showed large nucleus and a large amount of mitochondria in undifferentiated ES cells and many processes on the surfaces. In the first day after the adding of retinoic acid, some neuron-like cells with one, two or more processes were present. In the second day after adding RA and the first day after the plus of 10 microns Ara-C, a large amount of neuron-like cells appeared, with the formation of neuron-like networks. CONCLUSIONS: Combined use of RA and Ara-C can induce ES cells to differentiate into neuron-like cells. Our present preliminary study might provide insights into an alternative for the treatment of glaucomatous neuropathy by the transplantation of embryonic stem cells.

Animals↗
PubMed2000

[The secretion of chemokine RANTES in epithelial cells of nasal polyps and its significance].

OBJECTIVE: To investigate the effect of RANTES(regulated upon activation, normal T cell expressed and secreted) on chemotaxis, migration and accumulation of eosinophils in nasal polyps during epithelial immune responses. METHODS: The epithelial cells were obtained from nasal polyps and inferior turbinates in patients with snoring, and cultured for 24 and 48 hours with IL-1 beta(25 micrograms/L, 50 micrograms/L). RANTES was measured in the culture supernatant by ELISA. RESULTS: 1. On incubation with IL-1 beta, the epithelial cells from inferior turbinate and nasal polyps released 1.5-10 fold and 10-20 fold greater amounts of RANTES respectively than unstimulated samples. Significant increase in levels of RANTES was found in both groups(P < 0.001); 2. There was no difference between nasal polyp and inferior turbinate before incubation with IL-1 beta(P > 0.05) in the level of RANTES. After IL-1 beta stimulation, the concentration of RANTES was higher in polyp than in inferior turbinate (P < 0.001); 3. The expression of RANTES in both groups was dose-dependent and time-dependent upon stimulation of IL-1 beta. CONCLUSION: The epithelial cells of nasal mucosa are active end-organs, capable of releasing chemokine RANTES. In nasal polyps, RANTES has chemotactic activity for eosinophils and other inflammatory cells. It could affect the chemotaxis and eosinophil function and may play an important role in polyp formation.

Adult↗
PubMed2000

[Expression of apoptotic gene and FGF on olfactory bulb of rat and its significance].

OBJECTIVE: To study the expression and distribution of apoptotic gene Bcl-2 and Bax on olfactory of rat, and its relation with the FGF and to investigate the mechanism of senile dysosmia. METHODS: Ten young (3 months) and ten senile rats (24 months) were used in this study. After the removal of the heads of these rats, olfactory bulb were immediately fixed with neutralized formalin, followed with paraffin-embedding, serial sectioning, immunohistochemiscal staining and microscopic observing. RESULTS: The positive expression rate of Bcl-2 and FGF on olfactory bulb in young rats was significantly stronger than that in senile rats (P < 0.01). The positive expression rate of Bax in senile rats was a little stronger than that in young rats, but the differences were not statistically significant. (P > 0.05) CONCLUSION: The expression of FGF and anti-apoptotic gene Bcl-2 on olfactory bulb decrease with the increase of age. This suggests neuron apoptosis on olfactory bulb are regulated by neurotrophic factor, and directly related with senile dysosmia. The mitral cell apoptosis as a result of FGF decreased on olfactory bulb may play a key role in the senile dysosmia.

Animals↗
PubMed2000

[Primary study of Na+ channels in the epithelial cells of nasal polyps and of the effect of IL-1 beta on Na+ channels].

OBJECTIVE: To investigate the relationship between Na+ channels and nasal polyps and to study the effect of IL-1 beta on Na+ channels of epithelial cells of human normal nasal turbinate (NT) and nasal polyps (NP). METHODS: Serum-free cultured epithelial cells of NT from obstructive sleep apnea syndrome patients and NP were studied on collagen gel-coated membranes at an air-liquid interface using the patch-clamp technique in the cell-attached configuration. RESULTS: (1) The three Na+ absorption-related factors(the incidence of Na+ channels, the conductance of Na+ channels and the open probability of Na+ channels) were compared in NT cells and NP cells. There was no difference between NT and NP cells in the incidence(P > 0.05) and in the conductance(P > 0.05). However, the open probability was higher in NP cells compared to NT cells(P < 0.01). (2) Application of IL-1 beta increased significantly in the open probability of Na+ channels in NT and in NP cells (P < 0.01), the conductance of Na+ channels in NP cells was strongly increased by IL-1 beta(100 ng/ml)(P < 0.01). CONCLUSIONS: (1) The formation of NP is significantly correlated with increased Na+ absorption, the prolonged open time of Na+ channels is one of the most important factors. (2) IL-1 beta may upregulate Na+ permeability by prolonged open time of Na+ channels and increased conductance of Na+ channels, increased absorption of Na+ may lead to the growth and enlargement of NP.

Adolescent↗
PubMed2000

[Effect of macrophage nitric oxide on the ultrafiltration failure of long-term peritoneal dialysis].

OBJECTIVE: The regulation of macrophage nitric oxide on peritoneal lymphatic stomata was studied for revealing the mechanism of ultrafiltration failure during long-term peritoneal dialysis. METHODS: (1) The model of peritoneal dialysis was created by using peritoneal dialysate; (2) Dynamic measurements of nitric oxide (NO) were made during peritoneal dialysis and its cessation; (3) The pathological change of the peritoneal mesothelium in different dialysis time was observed by scanning electron microscope (SEM); (4) Dynamic changes of the peritoneal lymphatic stomata were studied during this experiment by using a computer image processing system attached to SEM. RESULTS: Numerous macrophages went into the peritoneal cavity through the lymphatic stomata to form a lot of milky spots during peritoneal dialysis. A great quantity of NO produced by macrophages damaging mesothelial cells and increasing numbers and density of lymphatic stomata. After 40 days of peritoneal dialysis, the diameters of the lymphatic stomata were significantly increased in Bieffe group (P < 0.05). During cessation of peritoneal dialysis, few macrophage milky spots were observed and NO quantity was gradually decreased. Then the mesothelium damage began to repair and the peritoneal lymphatic stomata tended to become normal. CONCLUSIONS: Our data demonstrate that a great quantity of NO produced by macrophages would damage peritoneal mesothelium and relax lymphatic stomata which enhance lymphatic reabsorption from the peritoneal cavity so as to make ultrafiltration failure on long-term peritoneal dialysis.

Absorption↗
PubMed2000

[Prediction of peritoneal fluid pancreatic amylase to histopathological change and prognosis of acute experimental necrotic pancreatitis of monkey].

OBJECTIVE: To observe the significance of peritoneal fluid pancreatic amylase in predicting the degree of histopathological change and prognosis of acute necrotic pancreatitis (ANP) of monkey. METHODS: Injection of the mixture of bile and trypsin into the pancreatic duct set up ANP monkey model. RESULTS: The severity of ANP depended on the injection rate and volume, in correlation to the peritoneal fluid pancreatic amylase (PF Amylase) in the early stage of ANP. With the rate (3-13 ml/min) and volume (0.1-1.0 ml/kg) of injection increase, the PF Amylase in the early stage of the ANP significantly went up. Meanwhile, the survival time was negatively correlated to the PF Amylase in the early stage (0.5 hour) of ANP (t = -9.06 InX + 129.85, r = -0.88, P < 0.01). CONCLUSIONS: The PF Amylase in the early stage of ANP can effectively predict the severity of ANP and prognosis.

Amylases↗
PubMed2000

[Study on the formation mechanism of soluble complexes containing bovine serum albumin and calcium hydroxyapatite and calcium carbonate].

Fourier transform infrared spectroscopy was used to study the composition and microstructure of soluble complexes produced by different initial mole ratios of bovine serum albumin(BSA) and calcium hydroxyapatite [Ca10(OH)2(PO4)6] and calcium carbonate (CaCO3) in aqueous solution. The band shifts and intensity variations suggested that calcium complexes with multiple ligands such as BSA, apatite, carbonate as well as the hydrogen bond network formed in titled system. The interactions increased the solubility of Ca10 (OH)2(PO4)6 and CaCO3 and the composition of soluble complexes is nonstoichiometric. The results provided an ideal model to investigated biomineralization process.

Calcium Carbonate↗
PubMed2000

[Influence on luminescence of Tb o-aminobenzolate complexes by second ligand].

Two Tb o-aminobenzolate complexes with different second ligands (phenanthroline and triphenyl phasphine oxide) were synthesized. Their structures and fluorescent properties were investigated by fluorescence spectroscopy and FTIR spectroscopy. The results indicate that the second ligand affected on the complexes luminescence by changing its structure.

Chelating Agents↗
PubMed2000

[FTIR study on the structures of bilirubin in solution].

The structures of bilirubin in solid-state, in HCCl3 and DMSO solution are investigated by FTIR spectroscopy. The results indicate that bilirubin have very different structures in solid-state and in solutions. The results also demonstrate that the structures vary in different solvents. There are six H-bonds in bilirubin molecule in solid-state, four in bilirubin molecule in HCCl3 solution and one in bilirubin molecule in DMSO solution.

Animals↗
PubMed2000

[The structure of DL-homocysteic acid in D2O solution].

DL-Homocysteic acid (DLH) is an important free amino acid in central nervous system of human body. In this paper the structure of DLH in D2O solution was discussed. The FTIR and FT-Raman spectra of DLH, which were obtained by Nicolet Magna-IR 750 II FTIR spectrometer and 950 FT-Raman spectrometer, were compared between its solid state and its D2O solution. The results indicated that the H-bonding structure of DLH in solid state was rearranged in D2O solution. The appearance of 1,620 and 1,408 cm-1 suggests the partly ionization of -COOH. From above, we can conclude that a new H-bonding structure of DLH was formed in D2O solution. The H-bond of C-O...H-N was replaced by C-O...D-O, and the H-bonds of -NH3+ and -SO3- were also varied by D2O molecular. Furthermore, the peak shift and the intensity changes of -CH2 in FTIR and FT-Raman spectra were also proved that the skeleton structure of DLH was changed in D2O solution. In addition, this new structure did not alter with the change of concentration of DLH.

Deuterium Oxide↗
PubMed2000

[The study of the microwave reaction of stearic acid and pentyl amine].

In this study, the microwave reaction of stearic acid and pentyl amine was investigated by FTIR spectroscopy. The results indicated that after mixing the two reactants together, pentyl ammonium stearate was created and it formed acid-salt structure with the stearic acid remained. The results also demonstrated that under microwave radiation, the pentyl ammonium stearate could be not only decomposed, but also dehydrated to form stearic pentyl amide. It suggested that the microwave radiation was an ideal technique to make this chemical reaction much faster and much more thorough.

Amines↗