Biomedical subjects

Ming Zhong

Publications and source records attributed to Ming Zhong.

44 records · Page 3Linked to original sources

PubMed2002

The effect of selective inhibition of cyclooxygenase (COX)-2 on acute cardiac allograft rejection.

BACKGROUND: Using a rat (Lewis-Wistar Furth) abdominal heterotopic transplantation model, we reported previously that the expression of cyclooxygenase (COX)-2 is increased in parallel with that of nitric oxide synthase (NOS)-2 during cardiac allograft rejection. METHODS: To investigate effects of COX-2 inhibition in this model, allograft recipients were treated orally (PO) with 5 mg/kg per day of the tetra substituted furanone selective COX-2 inhibitor 5,5-dimethyl-3-(3 fluorophenyl)-4-(4 methylsulfonal) phenyl-2 (5H)-furanone (DFU) in 1% methyl cellulose solution. RESULTS: In the treated animals, allograft survival was increased from 6.3+/-0.5 to 12.6+/-2.6 days (P = .001). At days 3 and 5 posttransplantation, there were reductions in the extent of the inflammatory infiltrate, endovasculitis, myocardial edema, and cardiomyocyte damage in rejecting allografts. The mean numbers of apoptotic cardiomyocytes determined with the terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL) technique were significantly reduced in DFU-treated grafts compared with untreated controls (P < 0.05). At day 3 posttransplantation, prostaglandin E2 synthesis by myocardial slices incubated with 100 microM bradykinin was reduced from 1,097+/-156 to 153+/-63 pg/mg of protein in the treated allografts (P < .005). At day 5, COX-2 protein and mRNA together with COX-2, NOS-2, and nitrotyrosine immunostaining in damaged cardiomyocytes were diminished in treated versus control grafts. CONCLUSION: The data indicate that the inhibition of COX-2 prolongs allograft survival and reduces myocardial damage and inflammation during acute cardiac allograft rejection.

Acute Disease↗

PubMed2002

Variant-type PML-RAR(alpha) fusion transcript in acute promyelocytic leukemia: use of a cryptic coding sequence from intron 2 of the RAR(alpha) gene and identification of a new clinical subtype resistant to retinoic acid therapy.

The physiologic actions of retinoic acids (RAs) are mediated through RA receptors (RARs) and retinoid X receptors (RXRs). The RAR(alpha) gene has drawn particular attention because it is the common target in all chromosomal translocations in acute promyelocytic leukemia (APL), a unique model in cancer research that responds to the effect of RA. In the great majority of patients with APL, RAR(alpha) is fused to the PML gene as a result of the t(15;17) translocation. Three distinct types of PML-RAR(alpha) transcripts, long (L), short (S), and variant (V), were identified. The V-type is characterized by truncation of exon 6 of PML and in some cases by the insertion of a variable "spacer" sequence between the truncated PML and RAR(alpha) mRNA fusion partners, although the precise mechanisms underlying formation of the V-type transcript remain unclear. To get further insights into the molecular basis of the t(15;17), we sequenced the entire genomic DNA region of RAR(alpha). Of note, all previously reported "spacer" sequences in V-type transcripts were found in intron 2 of the RAR(alpha) gene and most of these sequences were flanked by gt splice donor sites. In most cases, these "cryptic" coding sequences maintained the ORF of the chimeric transcript. Interestingly, two cases with a relatively long spacer sequence showed APL cellular and clinical resistance to RA treatment. In these cases, the aberrant V-type PML-RAR(alpha) protein displayed increased affinity to the nuclear corepressor protein SMRT, providing further evidence that RA exerts the therapeutic effect on APL through modulation of the RAR-corepressor interaction. Finally, among patients with the L- or S-type PML-RAR(alpha) fusion transcript, some consensus motifs were identified at the hotspots of the chromosome 17q breakpoints within intron 2 of RAR(alpha), strengthening the importance of this intron in the molecular pathogenesis of APL.

Antineoplastic Agents↗

PubMed2002

[Molecular-ecological technology of microorganisms and its application to research on environmental pollution].

Nucleicacid probe detection, PCR technique using primer, DNA sequential analysis, and electrophoresis separation and display were summarized and the application of these techniques to research on environmental pollution and future developing directions were discussed. It was pointed out that molecular-ecological technology of microorganisms are playing an important role in studying on relationships between microorganisms and contaminated environment. There are some important advances such as genetic adaptation and evolutionary mechanisms of microorganisms in contaminated environment, the positioning of pollutant-degrading genes of microorganisms and the construction of microbiological engineering bacteria, thus promoting the development of molecular ecology for bioremediation of contaminated environment.

Bacteria↗

PubMed2002

[RAPD markers linked to the stripe rust resistance gene Yr5 in the wheat variety Triticum spelta album].

A total of 520 10-mer random primers were used to identify the RAPD markers linked to the Yr5 gene between the near-isogenic line Yr5/6 x Avocet S and recurrent parent Avocet S. Three polymorphic DNA fragments, S1496(761), S1453(880) and S1418(1950), were found linked to the Yr5 gene. In which the genetic distance between S1496(761) and Yr5 gene was 2.7 cM. The fragment S1496(761) was recovered from the gel and cloned and sequenced. A pair of specific PCR primers was designed based on the sequence. The specific primers amplified the same fragment about 761bp as the random primer S1496 did. Because the primers could amplify another non-specific fragment, the PCR products must be analyzed by electrophoresis on polyacrylamide gels.

Basidiomycota↗

PubMed2002

Research on expression of telomerase in human odontogenic lesions.

OBJECTIVE: To study hTERT mRNA expression in ameloblastoma (AB) and odontogenic keratocyst (OKC) and to investigate genesis, development and biological characteristics of AB and OKC. METHODS: hTERT mRNA expression in 54 cases of AB, 16 cases of OKC, 7 cases of oral normal mucosa was detected by in situ hybridization. RESULTS: The positive rates of hTERT mRNA in AB, OKC, and oral normal mucosa were 94.4% (51/54), 87.5% (14/16), 1/7, respectively. There was significant statistical difference (P < 0.001). About clinicalpathology of AB, there was no difference for hTERT expression (P > 0.05) hTERT mRNA was positive in peripheral and stellate reticula cells. CONCLUSIONS: (1) hTERT activity plays an important role in genesis, development of AB. (2) hTERT positive rate is related to cell differentiation and clinical biological behavior.

Ameloblastoma↗

PubMed2002

[Growth of rifampin-dependent Mycobacterium tuberculosis in conditions without rifampin].

OBJECTIVE: To study the growth of rifampin-dependent Mycobacterium tuberculosis in conditions without rifampin. METHODS: A typical rifampin-dependent strain was identified and a single colony growing in the optimal concentration of rifampin was selected and inoculated (10(-4) mg/ml) to L-J and 12B liquid media, cultured at 37 degrees C. The bacterial growth and characteristics were studied. RESULTS: In the L-J medium containing rifampin, bacterial growth was observed in two weeks, but in the medium without rifampin tiny colonies were not observed until three weeks. In the 12B media with and without rifampin, bacterial growth was evident on day 9 and day 13 respectively. Thick and larger colonies and cauliflower-like growth were observed in media containing rifampin, but smaller colonies and fried egg-like growth were observed in media without rifampin. Microscopic study showed thick and heavily stained bacteria in media containing rifampin, but small and lightly stained bacteria in media without rifampin. Transmission electron microscopy demonstrated that bacteria growing in the presence of rifampin had complete cell walls, but those growing in the absence of rifampin had abnormal cell walls. CONCLUSION: Rifampin-dependent Mycobacterium tuberculosis may be changed into bacterial L-forms in media without rifampin.

Antibiotics, Antitubercular↗

PubMed2002

[Determination of chemical components of volatile oil from Cuminum cyminum L. by gas chromatography-mass spectrometry].

Volatile oil was extracted from Cuminum cyminum L. by using steam distillation. More than sixty peaks were separated and 49 compounds were identified by gas chromatography-mass spectrometry (GC-MS). The relative amounts of the components were determined by area normalization method. Among the 49 compounds identified, there were 16 hydrocarbons and 32 oxygenated compounds. The main compnents were cuminal and safranal (accounting for 32.26% and 24.46% respectively in the components identified). The other nine compounds with contents all over 1%, were monterpenes, sesquiterpenes, aromatic aldehydes and aromatic oxides etc. The other components with relatively small amounts were chiefly terpenes, terpenols, terpenals, terpenones, terpene esters and aromatic compounds. It is good to separate polar and apolar components in the volatile oil from Cuminum cyminum L. on the GC capillary column of moderate polarity.

Cuminum↗

PubMed2002

[Otorhinolaryngological neurofibromatosis].

OBJECTIVE: To investigate the growth characteristic, clinical manifestation, diagnosis and treatment of neurofibromatosis (NF) in otorhinolaryngology. METHODS: Eleven cases of NF from 1989 to 2000 were analyzed retrospectively, among which, there were 5 and 2 cases occurring in nasal cavity and parapharynx (NF I), respectively, and 4 bilateral acoustic neuromas (NF II). RESULTS: NF I and NF II had long courses of 2-30 years, with common clinical features and unique characteristics. All patients with NF were operated on under general anesthesia. The NFs in the nasal cavity and sinus were resected through the paranasal approach and parapharyngeal NF through the lateral cervical approach. Unilateral acoustic neuromas were removed via the sigmoid sinus posterior suboccipital approach, one case bilateral acoustic neuromas was operated on in 2 stages. No death happened in this series. CONCLUSION: Surgical treatment is the best way for the treatment of NF. Radiotherapy can be considered in case of NF I with an extensive invasion, obscure border and recurrence.

Adult↗