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Biomedical subjects

Z Deng

Publications and source records attributed to Z Deng.

At least 91 records · Page 5Linked to original sources
PubMed1997

Expression of monocyte chemoattractant protein-1 in monocytes and effects of native and oxidized very low density lipoproteins.

Monocyte chemoattractant protein-1 (MCP-1), a potent chemoattractant, is thought to play an important role in migration of monocytes into atherosclerotic lesions. The present study was designed to investigate the capacity of human peripheral blood monocytes to express MCP-1 and effects of native very low density lipoprotein (VLDL) and oxidized VLDL (OX-VLDL) on the expression. The total RNA was extracted from cultured monocytes, which were exposed to VLDL and OX-VLDL, and the media conditioned by monocytes were collected. MCP-1 mRNA expression was examined by Northern blot analysis. MCP-1 protein in conditioned media was determined by using sandwich ELISA. The results showed that monocytes can express MCP-1 after a 24 h incubation at 37 degrees C, and the expression was markedly increased by a exposure to OX-VLDL, whereas the expression was slightly increased when exposed to VLDL. It suggests that the capacity of monocytes to produce MCP-1 that recruits and activates circulating monocytes may be of considerable importance in atherogenesis, and oxidation of VLDL enhances its potential to promote atherogenesis.

Arteriosclerosis↗
PubMed1997

Characterization of polymer films of pyrrole derivatives for chemical sensing by cyclic voltammetry, X-ray photoelectron spectroscopy and vapour sorption studies.

Eight different conducting polymer films formed from pyrrole and N-substituted pyrrole derivatives were characterized by cyclic voltammetry, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy. In particular, the XPS of poly[N-butylpyrrole], poly[N-(2-carboxyethyl)pyrrole], poly[N-(6-hydroxyhexyl)pyrrole] and poly[N-(6-tetrahydropyranylhexyl)pyrrole] is reported for the first time. The vapour sorption properties of these films were also examined by forming the films onto the electrodes of thickness-shear mode acoustic wave sensors. The influence of the pendant side chain is apparent in both the electrochemical behaviour, composition, doping level, morphology and the nature and extent of polymer-vapour interactions. The latter can be rationalized by consideration of vapour physical properties and solvatochromic parameters.

Chemical Phenomena↗
PubMed1997

[Fixation of nonunion of pediatric middle and distal shaft of the femur with semicircular dynamic locked intramedullary nail].

From Oct. 1994 to Dec. 1996, 15 nonunions of pediatric middle and distal shaft of the femur due to previous osteomyelitis and pathologic fracture and/or failed internal fixation were treated with semicircular dynamic locked intramedullary nail (SDLIN). SDLIN was composed of a lateral and a medial nail, both of them were inserted into the medullary canal 1.5 cm above the epiphyseal line, and the tails were connected together by a bolt. All the 15 cases used iliac bone autograft for the defect. Follow-uped for an average of 16.3 months, all of them were healed in an average of 4.8 months, and excellent and good results were obtained in 86.7%. The results suggest that the SDLIN is effective and convenient for the fixation of the refractory nonunion of pediatric middle and distal shaft of the Femur.

Adolescent↗
PubMed1997

[Survey of smoking and human health in Guangdong province].

As part of the national plan in China, 28,979 residents or farmers were surveyed in 1991 in Guangdong province to investigate the relation between smoking and human health. The results showed that the total smoking rate was 40.2%, 58.8% was for male and 1.2% was for female. 56.4% was in city and 38.7% was in rural area. The beginning smoking age was 15-16 years old (5.5%). 8.5% smokers started smoking after 25 years old. Smoking can increase risk of diseases. The incidence of chronic bronchitis, hypertension, gastric ulcer and pulmonary TB in smoking group were significantly higher than that in non-smoking group. No difference was found in the symptoms of panting, cough and phlegm between the two groups. To control smoking is one of the important measures for human health.

Adolescent↗
PubMed1997

[Analysis and prevention of road traffic fatalities in Sichuan Province].

This is an epidemiological survey of the fatalities from road traffic accidents in Sichuan. All fatal accidents that occurred in Sichuan from January 1994 to December 1994 were analysed. The mortalities per million kilometers of vehicle travel, per 100,000 registered motor vehicles and per 100,000 resident population were 4.35, 42.41 and 3.92 respectively. These figures were compared with international death rates and those reported by other countries. The results showed that Sichuan had higher mortalities per million kilometers of vehicle travel and per 100,000 registered vehicles but lower mortality per 100,000 resident population, compared with some industrialized and rich develeping countries. The majority of the victims were males aged 21 to 40. Road traffic fatalities constituted the leading cause of all accident deaths. The cost of road accidents in Sichuan was estimated to be sixty million Yuan. Further strategies and methods to minimize the rate of such accidents have been suggested.

Accidents, Traffic↗
PubMed1997

[Sequence alterations in p53 gene of hepatocellular carcinoma from high aflatoxin risk area in Guangxi].

OBJECTIVE: Check on the sequence alterations of the p53 gene of hepatocellular carcinoma (HCC) in some areas of Guangxi. METHODS: 40 cases of archival HCC samples were divided into two groups. One includes 26 cases from Fusui--an area notorious for high risk in HCC, AFB1 and HBV; The other includes 14 cases from Yulin where both HCC and HBV were high but AFB1 may be low because rice low in AFB1 was the staple food. Exon 7 were sequenced by DNA direct sequencing. p53 mutational protein and HBsAg were examined by immunostaing. RESULTS: In the Fusui group, 16/26 (61.5%) cases showed mutation at codon 249 third position G to T transversion to form a hot-spot which is generally considered to be caused by AFB1. In the Yulin group, only one single place-Guigang showed p53 mutation clustered at the hot-spot like Fusui in 3/5 cases (60%), while the other cases demonstrated mutational points in various positions. CONCLUSION: Besides Qidong and South Africa, a third AFB1 high risk area was demonstrated where HCC is accompanied by p53 gene specific mutation.

Adult↗
PubMed1997

[Cloning and expression in Escherichia coli of an alkaline and thermostable exolipase from Pseudomonas pseudoalcaligenes].

A gene coding for an alkaline and thermostable exolipase of Pseudomonas pseudoalcaligenes was cloned into Escherichia coli LE392 by inserting Sau3 AI-generated DNA fragments into the BamHI site of pIJ285. Four colonies with esterase and lipase activities on the tributyrin agar plate were isolated by screening the constructed pseudomonas pseudoalcaligenes genomic library. Only one out of the four positive colonies showed lipase activity on the agar plate contatining olive oil and Rhodamine-B. Subclones of the 45 kb insert carrying lipase gene was obtained in E. coli HB101 using pUC118 as a vector, two of which (HB101 (pHZ1402) and HB101 (pHZ1403)), retained lipase activity, but the level seems to be different. They carried 3.0 kb and 2.9 kb inserts with a 2 kb overlapping sequence. The lipase activity of HB101 (pHZ1403) is about 4 times higher than that of HB101 (pHZ1402), as 5 times as that of original strain P. pseudoalcaligenes.

English Abstract↗
PubMed1997

[Dual-energy separation imaging on an X-ray direct digital imaging system].

A method of dual-energy separation of bone and soft tissue images of chest based on an X-ray direct digital imaging system has been investigated. In this paper, the optimal thickness of the filter for high energy X-ray beam is discussed. An algorithm of correction of scattered radiation is employed before the separation algorithm. The separated images will be shown in the paper. The result shows that it is possible to use an ordinary broad spectral X-ray beam to acquire the dual-energy images for routine X-ray diagnosis.

Humans↗
PubMed1997

[A method based on the theory of stochastic recursive identification for lossless compression of medical images].

This paper describes a method based on the theory of stochastic recursive identification for lossless compression of medical images detail. The performances of this method are compared with the existing method of DPCM through ten X-ray chest images. The experimental results clearly indicate that this method is very valid to realize lossless compression of medical images.

Electronic Data Processing↗
PubMed1997

[Analysis of apoptosis in premalignant and malignant epithelia of buccal mucosa].

To determine the relationship between apoptosis and carcinogenesis of oral mucosa, the distribution patterns of apoptosis in normal (N), inflammation (IF), dysplasia (DYS) and squamous cell carcinoma (SCC) of oral mucosa were evaluated by in situ end-labeling method. Results showed that the apoptosis levels in N and IF were relatively lower and stable, whereas the apoptosis of DYS was the highest one in all observed groups. The apoptosis of DYS and SCC were increased obviously higher than N and IF. The results indicated that apoptosis played an important role in premalignant lesion and malignancy of oral mucosa.

Apoptosis↗
PubMed1997

[SERS and electrochemistry studies on the inhibition of thiourea and phenyl-thiourea on iron].

An iron electrode was obtained by depositing a thin layer of iron on active silver electrode with overpotential deposition method. The E - I curve and SERS spectra of thiourea (TU) and phenyl-thiourea (PTU) adsorbed on the iron electrode surface were studied by means of electrochemistry and SERS spectroscopy. The results showed that both TU and PTU can be adsorbed on the iron electrode surface and the inhibition of PTU is better than TU in 0.1mol/L KCl solution. The adsorption mode of TU and PTU is similar in the interaction of S atom and iron surface. The cause of better inhibition effect of PTU lies in that the PTU can be more easily adsorbed on iron electrode because of more negative charge in its S atom and benzene ring in PTU is arranged away from the iron surface to form a rather compact adsorption layer due to steric hindrance.

English Abstract↗
PubMed1997

[Effects of oxidatively modified low density lipoprotein and very low density lipoprotein on the expression of MCP-1 in macrophages].

OBJECTIVE: To examine whether oxidatively modified low density lipoprotein (OX-VLDL) and very low density lipoprotein (OX-VLDL) induce the expression of MCP-1 mRNA and protein by rabbit peritoneal exudate macrophages, and to clarify what a role of both lipoproteins play in atherogenesis. METHODS: After exposure of the macrophages to 25 micrograms/ml of LDL, VLDL, OX-LDL and OX-VLDL respectively, and a 24 hour incubation at 37 degrees C, the total RNA was extracted from the cells by guanidinium isothiocyanate method, and the media conditioned by the cultured macrophages were collected. Meanwhile, MCP-1 protein in the conditioned media was determined by using sandwich ELISA. Monocyte migration induced by the media was assayed by micropore filter method using modified Boyden chamber. RESULTS: After a 24 hour exposure to OX-LDL and OX-VLDL, the MCP-1 mRNA expression in macrophages was markedly increased (3.2-fold and 3.4-fold, respectively), and the level of MCP-1 protein was also increased (2.2-fold and 2.5-fold, separately), and furthermore, the monocyte migration distance was significantly increased. However, the expression of MCP-1 mRNA and protein was only slightly increased when exposed to LDL or VLDL. CONCLUSIONS: Rabbit peritoneal exudate macrophages can express MCP-1 mRNA and protein, and OX-LDL and OX-VLDL induce stronger MCP-1 mRNA and protein expression in the cells.

Animals↗
PubMed1997

Study on the hydrolyzate of sugarcane bagasse to ethanol by fermentation.

Study of glucose and xylose utilization by Pichia stipitis in a limited oxygen supply condition revealed that the rate of glucose utilization decreased rapidly while that of xylose decreased slowly until the time that glucose and xylose were shown to level out, at which point the rate of xylose utilization increased rapidly. Based on the results, ethanol fermentation technology in continuous connective tower fermenters was advanced, e.g., fermentation by P. stipitis in an airlift loop tower focusing on xylose utilization and then residue glucose utilization by Saccharomyces cerevisiae in an overflow tower. When the fed hydrolyzate of bagasse was concentrated in five folds and the dilution rate was 0.1 h-1, the total utilization ratio of reducing sugar was 97.2%; the concentration of ethanol was 46.4 g/L.h.

Cellulose↗
PubMed1997

[A fast iterative algorithm for adaptive histogram equalization].

In this paper, we propose an iterative algorthm called FAHE., which is based on the relativity between the current local histogram and the one before the sliding window moving. Comparing with the basic AHE, the computing time of FAHE is decreased from 5 hours to 4 minutes on a 486dx/33 compatible computer, when using a 65 x 65 sliding window for a 512 x 512 with 8 bits gray-level range.

Algorithms↗
PubMed1997

[Employing deconvolution method for correcting scatter in radiography].

It is well known that the scattered-radiation (SR) results in degradation of the images contrast in digital X-ray radiograph. The main reason affecting radiographic image quality is the SR arising from interaction of the photons with object being radiographed and veiling glare from detector system in the II-TV chai imaging system. With the aim of improving the image quality, we employed the Gaussian function to approximate the scattered point spread function (PSF) and determined the fraction of SR, rho and the parameter, sigma experimentally on an individual system; then we built an inverse filter to process the digital chest X-ray images, which were acquired with the same system and transformed in 2-D Fourier tansform operation. The images processed were corrected by using a variable weihting factor and the resulting images are shown in this paper. The method provides a useful way for solving the problem of correction of the SR in digital X-ray images.

Algorithms↗
PubMed1997

[Internal fixation with U-shaped pin in the treatment of fracture-dislocation of the cervical spine].

Twenty cases with fracture-dislocation of the cervical spine were treated by U-shaped pin fixation. The U-shaped pin made of Steiman pin was used to hold sublaminar fixation of two segments above and below the vertebra of fracture. When atlas or axis was injured, a pair of small holes were drilled on the occipitale. The closed end of the U-Shaped pin was wired through the holes. Early postoperative ambulation was allowed without external fixation. 18 cases were followed up for 8-35 months. 5 cases of six patients with neurologic deficits recovered completely. The remaining one improved, no failure or loosening of the U-Shaped pin or wires was observed. Sound union of the bone grafts was obtained in all the patients. The results suggest that the operative procedure is simple, with sound fixation and satisfactory reduction and union of the fractures.

Adolescent↗