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Biomedical subjects

J Ni

Publications and source records attributed to J Ni.

209 records · Page 12Linked to original sources
PubMed1992

[The study of DNA fingerprint using probe directly labelled with horseradish peroxidase and enhanced chemiluminescence in forensic science application].

We describe here the technique of DNA probe directly labelled with horseradish peroxidase (HRP) and enhanced chemiluminescence (ECL) detection for determining DNA fingerprints. The patterns of DNA fingerprint were clear and with high distinction. The sensitivity of DNA fingerprint was 0.8 microgram, similar to the method of 32P labelling. The DNA fingerprints of 150 unrelated individuals were studied and showed that the probability of chance association of DNA fragments between random individuals was 3.7 x 10(-14). The method is stable, simple and quick, and can be used in individual identification and paternity test.

DNA Fingerprinting↗
PubMed1991

[Identification of tinglizi by derivative spectrum].

This paper reports a study on the application of derivative spectrum to the identification of tinglizi and its adulterants. The spectra of two normal species of tinglizi have been found identical, but those of six adulterants obviously different from the normal.

Drug Contamination↗
PubMed1990

Observations on the treatment of coronary heart disease by kuo guan qu yu ling.

Based on the therory of promoting flow of qi and dispersing blood stasis, the KUO GUAN QU YU LING coronary--dilating and stagnation--dispersing) powder in capsules were prepared for the treatment of 60 cases of coronary heart disease. After a 30 day course of treatment, cardiac ischemia was improved in 64.7% and the symptom of angina pectoris was relieved in 61.7% of the patients. This drug also acted to reduce blood lipids and to improve left cardiac function. Pharmacological study indicated that this preparation improved the tolerance of cardiac muscle against anoxia and prevented ventricular fibrillation and cardiac damage from ischemia.

Adult↗
PubMed1989

Effects of chronic optical defocus on the kitten's refractive status.

Lid closure initiated early in life produces axial myopia in a variety of species. However, it is currently not known what aspects of the anomalous visual experience associated with lid closure disrupt the emmetropization process and cause abnormal ocular axial elongation. This study was designed to determine if a degradation in the quality of the spatial characteristics of the retinal image was sufficient to produce an experimental myopia. Optical rearing procedures were employed to defocus one eye of developing kittens, and retinoscopic and ultrasonic procedures were used to evaluate the effects of chronic optical defocus on the kitten's refractive status. Different defocusing lens designs and rearing protocols were included to evaluate variables that may have confounded previous investigations. The major finding is that early chronic optical defocus results in axial myopia. The prevalence and magnitude of the induced refractive errors were dependent on the magnitude of optical defocus, but they were not affected by the sign or form of the defocusing lens. The results demonstrated that the potential for a clear retinal image is important for regulating normal ocular growth and maintaining a near emmetropic refractive status.

Animals↗
PubMed1989

[Study on Bacillus pumilus as a recipient strain for genetic engineering of Bacillus].

Bacillus pumilus 289 can be transformed easily by plasmid pUB110 through protoplast transformation with the frequency of 10(-5)--10(-3), similar to B. subtilis AS 1.1176, a derivative strain of B. subtilis 168. The regeneration frequency of its protoplast is only slightly lower than B. subtilis AS1.1176 (0.3-12.0% compare to 1.53--24.16%). Plasmid pUB110 can be maintained in both bacterial strains stably. The frequency of loss of the plasmid in both strains is lower than 3% after 45 generations in LB medium. But it is quite different that the hybrid plasmid (pUB110 with 3.9 kb foreign DNA fragment) can be maintained much more stably in B. pumilus 289 than in B. subtilis AS1.1176. The frequency of loss of the plasmid is lower than 5% in B. pumilus 289 and 24% in B. subtilis AS1.1176 after 25 generations when they grown in SH medium. The expression level of foreign gene in B. pumilus 289 is also much higher than that in B. subtilis AS1.1176. Therefore B. pumilus 289 is valuable to be exploited as recipient strain for genetic engineering of Bacillus in the future.

Bacillus↗
PubMedDate not supplied

Manufacture and evaluation of bioactive and biodegradable materials and scaffolds for tissue engineering.

For tissue regeneration and tissue engineering applications, a number of bioactive and biodegradable composites, either porous or non-porous, were fabricated. The newly developed materials included tricalcium phosphate reinforced polyhydroxybutyrate and its copolymer, poorly crystallized hydroxyapatite reinforced chitin, and plasma sprayed hydroxyapatite reinforced poly(L-lactic acid). It was shown that these new materials could be successfully produced using the manufacturing techniques adopted. In vitro experiments revealed that the incorporation of bioceramic particles in biodegradable polymers rendered the composites bioactive and significantly improved the ability of composites to induce the formation of bone-like apatite on their surfaces. Degradation of composite scaffolds in simulated body fluid was observed and could be due to the simultaneous degradation of polymer matrix and dissolution of bioceramic particles.

Journal Article↗
PubMedDate not supplied

Death-inducing tumour necrosis factor (TNF) superfamily ligands and receptors are transcribed in human placentae, cytotrophoblasts, placental macrophages and placental cell lines.

Human placentae and two of the cell types in placentae (cytotrophoblasts and macrophages) were examined by RT-PCR for transcripts of the eight TNF superfamily ligands known to induce death of activated immune cells, tumour cells, and virus-infected cells (TNFalpha, LT alpha, LT beta, FasL, TRAIL, TWEAK, LIGHT, 4-1BBL). Transcripts for all ligands were detected in term placenta but LT alpha and 4-1BBL were not detected in first trimester placenta. Although term cytotrophoblasts contained mRNAs specific for TNF alpha, LT alpha, TWEAK, and 4-1BBL, messages encoding LT beta, FasL, TRAIL, and LIGHT were absent. In term placental macrophages, messages for all ligands except 4-1BBL were present. Transcripts for the 14 receptors to which the ligands bind, six of which contain death-domains (TNFR1, Fas, DR3, DR4, DR5, DR6), were also identified using RT-PCR. Term and first trimester placentae contained transcripts for all receptors except 4-1BB. Although term cytotrophoblasts lacked receptor mRNA encoding 4-1BB and OPG, term placental macrophages lacked DcR1 and OPG. Detection of nearly all the death-inducing TNF superfamily ligands and their receptors in human placentae implies that these powerful cytokines contribute to programmed or activated cell death in this organ.

4-1BB Ligand↗
PubMedDate not supplied

Indoor air pollution and respiratory health in urban and rural China.

During the summer of 1999, information about respiratory health outcomes and relevant covariates was collected from 3,709 Chinese adults in Beijing, Anqing City, and rural communities in Anqing Prefecture. Indoor PM10 and SO2 were measured in a random sample of selected households. Using logistic regression and controlling for important covariates (excluding PM10 and SO2) and familial intraclass correlation, highly significant differences were found between study areas in the prevalences of chronic cough, chronic phlegm, wheeze, and shortness of breath, but not physician-diagnosed asthma. Generally, the lowest prevalence of respiratory symptoms was observed in Anqing City, a higher prevalence in rural Anqing, and the highest prevalence in Beijing. Median indoor concentrations of PM10 were similar in Anqing City (239 microg/m3) and rural Anqing (248 microg/m3), but much higher in Beijing (557 microg/m3). Median indoor concentrations of SO2 were similar in all three areas (Beijing: 14 microg/m3, Anqing City: 25 microg/m3, rural Anqing: 20 microg/m3).

Adult↗
PubMedDate not supplied

Stepwise gradient elution of capillary electrochromatography in the analysis of environmental samples.

Two modes of stepwise gradient elution of capillary electrochromatography were developed for the analysis of environmental samples on both a laboratory-made and a commercial CE instrument. Using the laboratory-made apparatus, another mobile phase was dropped directly into the inlet vial with a pipet. By this means, nine 2,4-dinitrophenylhydrazine (DNPH)-derivatized ketones and aldehydes were separated with high resolution. Not only was analysis time shortened by more than one half, but the detection limit was greatly improved compared to that in isocratic elution. The latter was achieved using the P/ACE 5510 system (Beckman Instruments, Fullerton, CA, U.S.A.), which moved the mobile phase vials automatically. The stop-flow technique was utilized during transfer. It had no effect on solute retention. With this method, the concentration and type of organic modifier in the mobile phase could be changed. A mixture of 13 aromatic hydrocarbons was separated completely in 14 min by changing the mobile phase from 80% methanol to 80% acetonitrile and 90% acetonitrile in a sequential step mode. The RSD of the retention time of each component in six consecutive injections was below 0.374%. All of these results demonstrate that stepwise gradient elution of capillary electrochromatography may be useful in the analysis of complex environmental samples.

Electrophoresis, Capillary↗