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Biomedical subjects

C Zhang

Publications and source records attributed to C Zhang.

At least 289 records · Page 16Linked to original sources
PubMed2000

[Changes of leukocyte rheologic characteristics and cell adhesion molecules in patients with multiple organ failure after severe trauma].

OBJECTIVE: To explore the changes of leukocyte rheologic characteristics and of cell adhesion molecule in patients with multiple organ failure (MOF) after severe trauma. METHODS: By using the erythrocyte deformability apparatus, platelet and thrombus adhesion dual-purpose apparatus and enzyme-linked immunosorbent assay (ELISA), We measured the leukocyte deformability (LD), leukocyte adhesion function (LAF), leukocyte CD18 expression, soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule (sVCAM-1) concentration in 36 MOF patients, 31 trauma patients, and 35 to be controls. RESULTS: The leukocyte filtration index (LFI), leukocyte adhesion rate (LAR), leukocyte CD18 expression, and sICAM-1 and sVCAM-1 concentration were significantly higher in MOF patients than in controls and trauma patients (F = 68.45 - 116.20, q = 12.161 - 21.374, P < 0.00), and the changes of these indicators in MOF deaths were more obvious than those in MOF survivors (t = 6.920 - 11. 665, P < 0.00). The LFI and LAR in MOF patients were positively related to leukocyte CD18 expression, sICAM-1, and sVCAM-1 concentration (r = 0.691 - 0.844, P < 0.001); LFI was positively related to LAR (r = 0.711, P < 0.001). CONCLUSION: The abnormalities of leukocyte rheologic characteristics and CAMs might be closely related to the occurrence of MOF and the severity of pathologic changes.

Adult↗
PubMed2000

[The effect of fluoride-arsenic exposure on the lipid peroxidation and antioxidation of the offspring of rats].

OBJECTIVE: To provide information on the effects of the offspring of rats exposed to fluoride-arsenic. METHODS: The levels of lipid peroxidation and the abilities of antioxidation were determined in the blood of the rats and their offsprings under two generations-one nest reproductive test. RESULTS: The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the blood decreased with the increase of exposure dose. For example, the activity of SOD, was 14.56, 13.74, 11.89 and 11.21 micromol x min(-1) x mg Hb(-1) in different dose groups of F(2), respectively. In contrast, the concentration of lipid peroxides (LPO) increased. Eight weeks after exposure, the activities of SOD and GSH-Px increased, the activity of SOD was 13.97, 13.55, 13.47 and 12.76 micromol x min(-1) x mg Hb(-1), respectively, and the concentration of LPO returned to normal level. CONCLUSION: Fluoride-arsenic exposure can cause oxidative damage of the rat's offspring.

Animals↗
PubMed2000

[Clinical effects of intra-arterial nitrogen mustard (NH2) chemotherapy during operation for oral cancer].

OBJECTIVE: To discuss the general and local side-effects and clinic appliance of the intra-arterial chemotherapy, and evaluate the short-time clinic effects of the intra-arterial chemotherapy. METHODS: From February, 1997 to December, 1997 11 patients with oral cancer (9 cases with lingual carcinoma, 2 cases with mouth carcinoma) were received one-shot chemotherapy during operation by NH2 catheterizing of lingual arteries (concentration of 1 mg/ml, dosage of 5 mg), and the other 16 oral cancer patients (13 cases with lingual carcinoma, 3 cases with mouth carcinoma) were only received operation as the control. At the same time, all patients were treated with Chinese flaps or Major pectoris myocutanous flaps homochronously. Then the general and local side-effects including the flap complexion were observed 1 week post-operatively and the follow-up was done in a shot time of 3-12 months. RESULTS: No obvious general and local side-effects (including blood, mal function of liver and kidney, flap complexion, vomit and hemiplegia) happened and all the 11 flaps (6 Chinese flaps, 5 major pectoris myocutanous flaps) were alive in the experimental group. The local recurrent rate of the experimental group was 9.1%, while the rate was 18.8% in the control group (following up of 3-12 months). There was no significant difference between the experiment and the control groups by Student t-test. CONCLUSION: The one-shot chemotherapy intra-operationally is a method with few side-effects, and it doesn't injure the homochronously reconstructed flaps. It might be an effective means of reducing the local recurrence of oral cancer.

Adult↗
PubMed2000

[Determining the distribution of Mutans Streptococci in human dental plaque by monoclonal antibody against SA I/II and SPAa of Mutans Streptococci].

OBJECTIVE: To explore the possibility of detecting the distribution of Mutans Streptococci in human dental plaque by Monoclonal antibody (WC2E10c, WC3A6d) against SA I/II and SPAa of Mutans Streptococci, which was prepared in our lab. METHODS: 60 subjects were divided into the experimental group and the control group. The distributions of Mutans Streptococci (serotype c and d) in dental plaques were detected in 60 subjects by the clonal blot technique. Positive colonies were examined by bacterial morphology, serology, biochemistry and SDS-PAGE. RESULTS: Bacterial colony was significantly different between the experimental group and the control group with eye observation. Colonies of the experimental group were deep brown and easily differentiated, but colonies of control group were white. Brown colonies were proved to be Mutans Streptococci (serotype c and d) by using assay of bacterial morphology, serology, biochemistry and SDS-PAGE, but white colonies were not. CONCLUSION: McAbs (WC2E10c, WC3A6d) were shown high specificity in Mutans Streptococci (Serotype c and d) of human dental plaques.

Adolescent↗
PubMed2000

[Cloning and sequence analysis of E0 gene of hog cholera virus lapinized Chinese strain and virulent shimen strain].

According to the published nucleotide sequences of genome of hog cholera virus, one pair of specific primers were designed and synthesized. From the spleen of rabbits which were infected with HCLV and HCV Shimen strain infected pig blood, the two E0 genes were amplified by RT-PCR. The amplified fragments were cloned into pGEM-T vector and sequenced. Sequence analysis showed nucleotide sequence and deduced amino acid sequence homologies of the E0 gene between HCLV and Shimen strain were 95.0% and 94.3%. There was 13 amino acid substitutions between them. One N-glycosylation site was missing from E0 gene of the Shimen strain. The nucleotide sequence homologies of the Shimen strain with the ALD, GPE-, Brescia and Alfort strains were 97.4%, 96.5%, 92.2% and 86.5%, respectively, the deduced amino acid sequence homologies were 97.4%, 96.0%, 95.2% and 92.5%, respectively. The nucleotide sequence homologies of E0 gene of the HCLV strain with the ALD, GPE-, Brescia and Alfort strains were 95.6%, 94.9%, 91.3% and 85.5%, respectively, the deduced amino acid sequence homologies were 93.4%, 92.5%, 91.6% and 90.7%, respectively. E0 gene from HCV was shown to be similar to a family of fungal and plant ribonuclease. The catalytically important residues were 28 to 40 and 71 to 89 of HCV E0 gene.

Amino Acid Sequence↗
PubMed2000

[A actinomycete strain C3905 producing antitumor antibiotic sandramycin from Antarctica].

A nocardioform actinomycete strain C3905 was isolated from a soil sample collected in King Geoge island, Antarctica. Its aerial mycelium is white, substrate mycelium is colorless to cream or pink. The hyphae of mycelium 0.5 micron-0.8 micron in diameter and they fragment into irregular rod to coccoid elements with smooth surface. Cell wall type I. The mycolic acids are lacking. Mk-9(H4) is the predominant menaquinone component. Phospholipid type PI. The G + C content of DNA is 68.3-68.9 mol%. Facultative psychrophile. The optimum temperature for growth is 15 degrees C-20 degrees C. Produces antitumor antibiotic sandramycin. Based on the characteristics above as well as the investigation of the molecular genetics. We propose that strain C3905 should be placed in the Nocardioides albus as a variant, named Nocardioides albus var. antarcticus.

Actinomycetales↗
PubMed2000

[An investigation of bioartificial pancreas for treatment of diabetes mellitus].

Bioartificial pancreas(BAP) made up of rat islet, agarose and collagen was developed in this experiment to cure the diabetes mellitus and prevent immune rejection of the islet xenograft. The insulin secretion function, immunoprotection and effect of BAP on the treatment of diabetes mellitus in mice were investigated. The results showed that the BAP maintained the insulin secretion function of islet, decreased the immunogenicity of islet xenograft and normalized the metabolic disturbances of carbohydrate in diabetic mice. These indicate that the BAP composed of the islet, agarose and collagen is an alternate approach to therapy for diabetes mellitus and to remission of immune rejection of the islet xenograft.

Animals↗
PubMed2000

[Fuzzy space based segmentation algorithm on periosteum medical image processing].

Object description in medical image often has the property of fuzziness, and with the development of computing, fuzzy logical theories are progressively used in medical image processing. Color medical images differ in spacial presentation and fuzzy description from grey-scale images and must be analyzed by special methods. In this paper, a new method of bone cell segmentation based on fuzzy logical theories is presented. With the utilization of fuzzy set theories in the steps of color enhancing, feature extraction and automatical segmentation, bone cells are detected from the background. The method has the advantages of high accuracy and flexibility to many situations. Experiments of bone cell images have proved that it is a fast and effective method.

Algorithms↗
PubMed2000

[Observation and analyses on voice changes in the normal aged].

OBJECTIVE: To measure the voice samples of the normal aged in order to systemically study the features of the voice changes. METHOD: To collect and analyze 146 voice samples of the normal aged with sonogram. RESULT: The fundamental frequency of the voice of the aged decreases and rises in the male more than 80 years older. The low frequency harmonics are regulation and the intensity is strong in the formant of the aged. The difference reduces in voice between male and female. The harmonics to noise ratio tends downwards and the amplitude perturbation quotient tends upwards along with the growth of age in the aged male. The changes of the above-mentioned parameters are not significant in the aged female. CONCLUSION: The voice changes are normal physiological ones in the normal aged. The changes of the parameters are used to evaluate normal aged voice and abnormal one. The changes show that the function in the aged phonation tends to decline to a certain extent and it must be protected and be trained.

Aged↗
PubMed2000

[Inhibition of extracts of ampelopsis sinica roots on DHBVsAg in sera of ducklings].

The ducklings, which are infected with Duck HBV to produce DHBVsAg in sera in advance, are treated with extracts from Ampelopsis sinica roots and some of them are treated with interferon alpha (INF) as positive control group. According the titer of DHBVsAg in Ducklings sera and the results of observing the tissues of the duckling's livers, it is demonstrated that the extracts of Ampelopsis sinica roots possess a certain action inhibiting DHBV and the action is enduring.

Ampelopsis↗
PubMed2000

[Raman spectra and IR spectra of 3-triphenylgermyl-1,1-diphenyl-1-butanol and its derivatives].

The Raman spectra and FTIR spectra of 3-triphenylgermyl-1,1-diphenyl-1-propanol (A), 3-triphenylgermyl-1,1-diphenyl-1-butanol (B) and 3-triphenylgermyl-2-methyl-1,1-diphenyl-1-propanol (C) have been measured and analyzed. In Raman spectra of these compounds, the Ge--Ph stretching vibrations are near 1,000 cm-1, and the Ge--C stretching vibrations are 594.1 (for A), 578.7 (for B), 599.2 cm-1 (for C). The spectra show that the three compounds have similar molecular vibration characteristics.

English Abstract↗
PubMed2000

[The effective dielectric function of porous SiO2 glass].

In this paper, we discussed the effective dielectric function of porous SiO2 glass with pore size 7.5 nm. We briefly discussed different formulae proposed by different theoretical models of porous systems, and compared the relationship of effective dielectric functions changing with different porosity of porous SiO2 of each formula. Through comparing the experimental spectra and the theoretical spectra of each formula, we found the equation ln epsilon e = theta 1 ln epsilon 1 + theta 2 + theta 2 ln epsilon 2 best indicates the effective dielectric function of porous SiO2. This work is helpful in selecting special absorption materials.

English Abstract↗
PubMed1999

Iron reduction by psychrotrophic enrichment cultures.

Psychrotrophic (<20 degrees C) enrichment cultures from deep Pacific marine sediments and Alaskan tundra permafrost reduced ferric iron when using organic acids or H(2) as electron donors. The representative culture W3-7 from the Pacific sediments grew fastest at 10 degrees C, which was 5-fold faster than at 25 degrees C and more than 40-fold faster than at 4 degrees C. Fe(III) reduction was also the fastest at 10 degrees C, which was 2-fold faster than at 25 degrees C and 12-fold faster than at 4 degrees C. Overall, about 80% of the enrichment cultures exhibited microbial Fe(III) reduction under psychrotrophic conditions. These results indicated that microbial iron reduction is likely widespread in cold natural environments and may play important roles in cycling of iron and organic matter over geological times.

Journal Article↗
PubMed1999

Selective expression of the large neutral amino acid transporter at the blood-brain barrier.

Amino acid supply in brain is regulated by the activity of the large neutral amino acid transporter (LAT) at the brain capillary endothelial cell, which forms the blood-brain barrier (BBB) in vivo. Bovine BBB poly(A)(+) RNA was isolated from 2.0 kg of fresh bovine brain and size fractionated on a sucrose density gradient, and a size-fractionated bovine BBB cDNA library in the pSPORT vector was prepared. The full-length cDNA encoding the bovine BBB LAT was isolated from this library, and the predicted amino acid sequence was 89-92% identical to the LAT1 isoform. The bovine BBB LAT1 mRNA produced a 10-fold enhancement in tryptophan transport into frog oocytes coinjected with bovine BBB LAT1 mRNA and the mRNA for 4F2hc, which encodes the heavy chain of the heterodimer. Tryptophan transport into the mRNA-injected oocytes was sodium independent and was specifically inhibited by other large neutral amino acids, and the K(m) of tryptophan transport was 31.5 +/- 5.5 microM. Northern blotting with the bovine BBB LAT1 cDNA showed that the LAT1 mRNA is 100-fold higher in isolated bovine brain capillaries compared with C6 rat glioma cells or rat brain, and the LAT1 mRNA was not detected in rat liver, heart, lung, or kidney. These studies show that the LAT1 transcript is selectively expressed at the BBB compared with other tissues, and the abundance of the LAT1 mRNA at the BBB is manyfold higher than that of transcripts such as the 4F2hc antigen, actin, or the Glut1 glucose transporter.

Amino Acid Sequence↗
PubMed1999

Gas chromatographic-mass spectrometric analysis of urinary sugar and sugar alcohols during pregnancy.

A refined and simplified method has been developed for the simultaneous analysis of urinary sugar and sugar alcohols after urease treatment by using capillary gas chromatography-mass spectrometry (GC-MS). Since carbohydrate metabolism during pregnancy is considered to be diabetogenic, our interest has been concentrated on understanding the mechanism of the metabolic deviation by assessing the glucose excursion and glucose fluxes. The present study suggests that changes of the levels of glucose, sorbitol, fructose, myo-inositol, and 1,5-anhydro-D-glucitol (1,5-AG) may reflect a mild alteration in carbohydrate metabolism that goes undetected by conventional diabetic indicators.

Carbohydrates↗
PubMed1999

Functional interaction of DFF35 and DFF45 with caspase-activated DNA fragmentation nuclease DFF40.

DNA fragmentation factor (DFF) functions downstream of caspase-3 and directly triggers DNA fragmentation during apoptosis. Here we described the identification and characterization of DFF35, an isoform of DFF45 comprised of 268 amino acids. Functional assays have shown that only DFF45, not DFF35, can assist in the synthesis of highly active DFF40. Using the deletion mutants, we mapped the function domains of DFF35/45 and demonstrated that the intact structure/conformation of DFF45 is essential for it to function as a chaperone and assist in the synthesis of active DFF40. Whereas the amino acid residues 101-180 of DFF35/45 mediate its binding to DFF40, the amino acid residues 23-100, which is homologous between DFF35/45 and DFF40, may function to inhibit the activity of DFF40. In contrast to DFF45, DFF35 cannot work as a chaperone, but it can bind to DFF40 more strongly than DFF45 and can inhibit its nuclease activity. These findings suggest that DFF35 may function in vivo as an important alternative mechanism to inhibit the activity of DFF40 and further, that the inhibitory effects of both DFF35 and DFF45 on DFF40 can put the death machinery under strict control.

Amino Acid Sequence↗