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Biomedical subjects

X Z Dong

Publications and source records attributed to X Z Dong.

9 recordsLinked to original sources
PubMed2002

The preparation and characterization of an antimicrobial polypeptide from the loach, Misgurnus anguillicaudatus.

Using Sephadex G-50 gel filtration, DEAE-52 cellulose ion-exchange chromatography, and an improved polyacrylamide gel electrophoresis together with electroelution, a novel polypeptide with antimicrobial activity in vitro was isolated and characterized from loach, Misgurnus anguillicaudatus. The polypeptide, named MAPP, contains about 94 residues containing l0 different amino acids, of which cysteine was the most abundant. No alkaline residue was found in MAPP. MAPP is a single-chain polypeptide with Mw of about 9800Da and pI of about 4.78; the N-terminus of MAPP was CFGWN. MAPP showed good inhibition of various bacteria including Bacillus subtilis, Escherichia coli, and Staphylococcus aureus. MAPP is thermally stable with more than 70% inhibitory bioactivity remaining after treatment at 60 degrees C for 30min. In addition, MAPP could inhibit the autoxidation of pyrogallol with a high efficiency. Similarity searches by comparing amino acid composition, MS-fingerprint, and the N-terminus of MAPP demonstrated that no protein exactly matched MAPP in databases around the world.

Animals↗
PubMed2001

[The study on non-contact detection of breathing and heartbeat based on radar principles].

The paper introduces the design of hardware and software of non-contact detection system for breathing and heartbeat in human body with radar principles and technology. The detection technology is discussed. Under conditions of the illuminating power P < 1 mW and the distance S < 10 m, the non-contact breathing and heartbeat measurement, can be in different positions and with different clothing on the subject. The results show that the system with the technology has a high sensitivity, and is harmless to the health. It is a practicable non-contact detection technology for breathing and heartbeat of human body.

Adult↗
PubMed2000

[Design of the system for detecting impedance cardiography based on windows plantform].

In this paper is introduced systematically the design of the system for detecting impedance cardiography (ICG) based on Windows plantform. The three major ICG indexes of 30 students have been detected by the designed system in the clinical application, and conform with the results from the reference. On the other hand, compared with the system based on DOS plantform, the system has higher detection speed, and becomes more convenient, more flexible by the introduction of Mouse.

Adult↗
PubMed1999

Population distributions of allele frequency of apolipoprotein E by age and gender in Han Chinese.

AIM: To study apolipoproteins E (ApoE) allele frequency in Han Chinese based on age and gender from Shanghai metropolitan area. METHODS: Healthy Han Chinese people (F: 237 and M: 412) were involved in this study. ApoE gene was amplified by PCR using the forward primer: 5'-GGC ACG GCT GTC CAA GGA GCT-3' and reverse primer: 5'-GAT GGC GCT GAG GCC GCG CT-3'. The PCR product was digested directly with 5 units of CfoI and separated by a 20% polyacrylamide nondenaturing gel. RESULTS: ApoE*3 was the commonest allele which accounted for 86.4% of the isoforms, and ApoE*2 and ApoE*4 accounted for 6.2% and 7.5%, respectively. The allele and genotype frequencies were in Hardy-Weinberg equilibrium by comparison with that of the corresponding theoretical distribution (P > 0.05). CONCLUSION: The frequencies of ApoE*2, ApoE*3, and ApoE*4 were demonstrated in the normal Chinese population.

Adult↗
PubMed1991

Degradation of galactomannan by a Clostridium butyricum strain.

An anaerobic, sporeforming, galactomannan-degrading bacterium was isolated from methanogenic granular sludge of an UASB reactor used for treatment of wastewater from a sugar refinery. The isolate degraded the polymer rapidly (doubling time was 55 min) and completely in mineral media. The bacterium was classified as Clostridium butyricum; the main products were acetate, butyrate, hydrogen, formate, and presumably CO2. The strain produced extracellular endo-mannanase, cell-associated exo-mannanase and intracellular alpha-galactosidase activity. The mannanases were present when grown on galactomannan, but not after growth on glucose, galactose, or mannose.

Biodegradation, Environmental↗
PubMed1990

First isolation of Xanthomonas campestris from the blood of a Chinese woman.

Xanthomonas campestris isolated from the blood of a patient with a fever was first reported. Xanthomonas campestris is a bacterium that can cause black rot of some vegetables, such as rape. Chinese cabbage, etc. Human infection due to X. campestris has not been reported so far. The characteristics of this organism, including morphology, staining, physiology and biochemistry were studied. We believe that X. campestris is also one of the opportunistic pathogens, which can infect compromised host.

Cerebral Hemorrhage↗
PubMedDate not supplied

Non-mutans streptococci in patients receiving radiotherapy in the head and neck area.

OBJECTIVE: To study mutans and non-mutans streptococci in patients after radiotherapy of the head and neck. METHODS: Oral rinse samples collected from nasopharyngeal carcinoma patients before and after radiotherapy were diluted and cultured on nonselective and selective media for enumeration of total cultivable plaque flora, mutans and non-mutans streptococci and lactobacilli. Non-mutans streptococci were identified biochemically and by 16S rDNA sequence homology analysis. RESULTS: After irradiation, mutans streptococci were not isolated; the levels of Streptococcus mitis and lactobacilli increased significantly. The level of Streptococcus salivarius increased, but the significance was the borderline. The level of Streptococcus sanguis decreased significantly after irradiation. The abundance of other oral streptococci species showed no significant changes. CONCLUSIONS: S. mitis and S. salivarius are the predominant non-mutans streptococci in the high-caries-risk oral flora following radiotherapy.

Adult↗