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Biomedical subjects

D Cai

Publications and source records attributed to D Cai.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Changes of inflammatory mediator in aucte necrotizing pancreatitis and effect of somatostatin analogne stilamin in rats].

OBJECTIVES: To investigate the changes of inflammatory mediator in ANP and to explore the effectiveness of stilamin treatment on ANP. METHODS: SD rats were divided into experimental groups (ANP = 12, ANP + NS = 10, ANP + Stilamin = 12) and control group (NC = 10). Rat ANP models were made by retrograde injection of 3.5% sodium taurocholate 2.5 ml/kg into the pancreatic duct, and treated by intravenous injection of stilamin 84 micrograms.kg-1.d-1 or same amount of normal saline respectively. Serum IL-1 beta, IL-6, IL-12, TNF-alpha, PLA2, amylase and endotoxin were examined. Finally, the morphology and pathology of the pancreas, liver, lung, heart and kidney, as well as the electronmicroscopical investigation of liver and lung cells were observed. RESULTS: The mean IL-1 beta, IL-6, IL-12, TNF-alpha, in the ANP and ANP + NS group were higher than those in the ANP + stilamin group and Control group (P < 0.01). The endotoxin, amlyase, PLA2 level in the ANP + stilamin group was lower than those in the ANP and ANP + NS groups (P < 0.001). ANP significantly increased white blood cell chemotax and infiltration, as well as hemorrhagic focus in liver, kidney and lung, but the pathological examinations of the liver, pancreas, lung and kidney demonstrated much less destruction in the stilamin group. CONCLUSIONS: Inflammatory cytokins play an essential role to induce pathophysiological process of ANP, and its related MODS may be effectively prevented and treated by stilamin.

Animals↗
PubMed1996

Retrovirus-mediated wild-type p53 gene transfer to tumors of patients with lung cancer.

A retroviral vector containing the wild-type p53 gene under control of a beta-actin promoter was produced to mediate transfer of wild-type p53 into human non-small cell lung cancers by direct injection. Nine patients whose conventional treatments failed were entered into the study. No clinically significant vector-related toxic effects were noted up to five months after treatment. In situ hybridization and DNA polymerase chain reaction showed vector-p53 sequences in posttreatment biopsies. Apoptosis (programmed cell death) was more frequent in posttreatment biopsies than in pretreatment biopsies. Tumor regression was noted in three patients, and tumor growth stabilized in three other patients.

Aged↗
PubMed1996

Long-term oral administration of L-arginine enhances endothelium-dependent vasorelaxation and inhibits neointimal thickening after endothelial denudation in rats.

OBJECTIVE: To further prove the hypothesis that local decrease of nitric oxide (NO) synthesis and/or its activity might be critically important in the disturbance of vascular homeostasis after vascular injuries. METHODS: Intimal thickening model induced by air-drying denudation of rat right common carotid artery was performed to evaluate the effects of long-term oral administration of L-arginine on neointimal thickening and acetylcholine-induced endothelium-dependent vasorelaxation (EDR) by histomorphometric and functional studies. RESULTS: Reductions in EDR function persisted and simultaneously developed prominent neointimal thickening by 14 days after denudation. Long-term oral supplementation of L-arginine (1 g/kg/day) significantly enhanced EDR from 43.5% +/- 12.35% to 68.8% +/- 9.0% (n = 10, P < 0.001) and reduced neointimal thickening from 62.45 microns +/- 11.26 microns to 21.45 microns +/- 6.34 microns (n = 10, P < 0.001) as compared with each control animals. CONCLUSIONS: This study shows that oral administration of L-arginine significantly inhibits neointimal thickening and preserves NO-mediated EDR in experimental endothelial denudation, suggesting an important role for L-arginine, NO pathway in the regulation of vascular homeostasis after endothelial injury which might be salutary in prevention restenosis after coronary angioplasty.

Administration, Oral↗
PubMed1995

[Changes in cytosolic free calcium and thromboxane B2 synthesis in platelets from diabetic subjects].

Using fura-2, a fluorescence indicator, we evaluated the changes of platelet cytosolic free calcium concentration ([Ca2+]i) and its role in regulation of thromboxane B2 (TXB2) synthesis in patients with diabetes mellitus (DM group, n = 27) and in healthy subjects (control group, n = 15). The A23187-evoked elevation of [Ca2+]i and TXB2 production were higher in the DM group than in the control group (P < 0.01 respectively). The rise in [Ca2+]i was correlated positively with TXB2 production. In contrast, stimulation with arachidonic acid, TXB2 production was unaltered between the groups, although arachidonate-induced [Ca2+]i was higher in the DM group than in the control group (P < 0.05). The results suggested that changes in platelets [Ca2+]i in diabetic subjects may contribute to increase in TXB2 synthesis, involved libration of free arachidonate from membrance phospholipids by the action of phospholipases. Since no significant difference was found between the diabetic patients with microangiopathy (n = 13) and without microangiopathy (n = 14), the results above may be involved in the development of diabetic microangiopathy.

Biological Transport, Active↗
PubMed1995

[Surgical treatment of benign stenosis of the esophagus].

From Nov. 1972 to 1983 Oct., 88 patients with benign stenosis of the esophagus were operated on. The youngest patients was 18 months, and the oldest 63 years. From corrosive injury of esophagus to operation, the shortest period was 13 days and longest 10 years (mean 120 days). In 85 patients, transverse colon was used to replace the esophagus substernally. In 2 patients, reconstruction was done by gastric tube. One patient used transverse colon and part of descending colon. Preoperative gastrostomy was made in 5 patients. There was no operative mortality. One patient developed anastomotic stenosis postoperatively. He refused reoperation and died. The remaining patients survived with a normal life. For the reconstruction of esophagus, problems such as choice of grafts, time of operation, resection of scar or not, and place of anastomosis were discussed.

Adolescent↗
PubMed1995

[Esophagogastrostomy covered by sero-muscular flap of gastric wall in the treatment of gastric cardia cancer in 100 cases].

A new operative procedure-esophagogastrostmy covered by sero-muscular flap of gastric wall to treat cancer of gastric cardia was designed by the authors in order to prevent anastomotic complications. One hundred cases with cases of gastric cardiac 97 cases with adenocarcinoma and 3 cases with squamous cell carcinoma of esophago-cardiac iunction were treated with the new anastomotic method without operative mortality and anastomotic complicatins within one year after surgery.

Adenocarcinoma↗
PubMed1995

[P-NMR analysis of the hepatic cell energetic metabolism in tumor-bearing mice by moxibustion treatment].

The new technique, NMR (nuclear magnetic resonance) spectrum analysis was used in this research to measure the state of energetic metabolism of hepatic cells at the organic level. The experimental results demonstrated that moxibustion on Guanyuan (CV4) point could remarkably increase the ATP molecules in the hepatic cells, significantly raise the thermodynamic reserve and phosphate potential of the hepatic cells, so as to enhance the functional activities of liver. It is discussed here of the mechanism of anti-tumor by moxibustion treatment and of the theory of warming the kidney and enhancing the Yang to tonify to energetic Qi by moxibustion on Guanyuan point.

Animals↗
PubMed1994

The thylakoid translocation of subunit 3 of photosystem I, the psaF gene product, depends on a bipartite transit peptide and proceeds along an azide-sensitive pathway.

Subunit 3 of photosystem I (PSI-3), the product of the nuclear psaF gene, is the docking protein for plastocyanin during photosynthetic electron transport in thylakoid membranes and is synthesized in the cytosol with a transit peptide that resembles structurally the bipartite targeting signals of hydrophilic, lumenal components such as plastocyanin. In organello import experiments performed with the authentic PSI-3 precursor and chimeric polypeptides consisting of residue-correct fusions of transit peptides and mature proteins derived from different plastid proteins demonstrate that the PSI-3 transit peptide is indeed capable of translocating proteins into the thylakoid lumen and that, conversely, mature PSI-3 depends on a bipartite transit peptide for its thylakoid transfer. Of the three recently described translocation/integration pathways for nucleus-encoded proteins carrying bipartite transit peptides that are distinct in their physiological requirements and strictly protein-specific, PSI-3, like plastocyanin and the 33-kDa protein of the oxygen-evolving complex, is translocated by a pathway that involves stromal factors but no proton gradient across the membrane. It is not affected by saturating amounts of the precursor for the 23-kDa protein of the oxygen-evolving complex that follows the latter route. Thylakoid translocation of PSI-3 is, however, impaired in the presence of sodium azide, which indicates that a homolog to the bacterial SecA protein might be involved in this process suggesting, thus, a prokaryote-like translocation pathway. The azide-sensitive factor appears to interact predominantly with the transit peptide of a precursor protein, since chimeras consisting of a presequence from an azide-resistant precursor and a mature part of an azide-sensitive polypeptide are still translocated in the presence of the inhibitor.

Azides↗
PubMed1994

Evidence of a self-catalytic mechanism of 2,4,5-trihydroxyphenylalanine quinone biogenesis in yeast copper amine oxidase.

Copper amine oxidases are representative of a new class of redox enzymes that contain a peptide-bound quinone cofactor, generated by posttranslational modification of amino acid side chain(s). We have investigated the mechanism for the biogenesis of 2,4,5-trihydroxyphenylalanine quinone (TPQ) in amine oxidase with two site-specific mutants of the yeast methylamine oxidase. Our results show that the capacity for TPQ formation in vivo is abolished when a putative ligand to copper, His-456, is changed to Asp; this H456D mutant binds copper at a low level (approximately 4.1%), relative to the wild-type protein. In contrast, altering the active site consensus sequence that contains the precursor tyrosine does not affect TPQ production. The data implicate a self-catalysis mechanism for TPQ biogenesis, in which the protein-bound copper plays a key role. We propose that the minimal information required for TPQ biogenesis lies in a structural motif consisting of the copper site and the precursor tyrosine.

Amine Oxidase (Copper-Containing)↗