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Biomedical subjects

Y Zhuang

Publications and source records attributed to Y Zhuang.

At least 55 records · Page 3Linked to original sources
PubMed1999

Molecular mechanisms of drug resistance in Mycobacterium tuberculosis clinical isolates.

OBJECTIVE: To study the molecular mechanisms of drug resistance in Mycobacterium (M). tuberculosis, to evaluate the value of the beta subunit of RNA polymerase (rpoB), the ribosomal siz protein (rpsL), 16Sr RNA (rrs), catalase-peroxidase gene (katG) genes, and inhA regulatory sequence as genetic markers for rifampin (RFP), streptomycin (SM), isoniazid (INH) resistance, and to develop new methods for detecting the drug resistance. METHOD: The rpoB, rpsL, rrs, katG genes, and inhA regulatory sequence in 85 M. tuberculosis isolates were analyzed with polymerase chain reaction (PCR), PCR-single-stranded conformation polymorphism analyses (SSCP), PCR-nucleotide sequence analyses (NS) and PCR-restriction fragment length polymorphism (RFLP). RESULTS: The sensitivity of amplifying the drug-resistant genes with PCR was 1-10 pg DNA. Twenty-eight drug-sensitive strains had no alterations in the rpoB, rpsL, rrs, katG genes, and inhA regulatory sequences. 93.3% of 45 M. tuberculosis RFP-resistant (RFPr) isolates had rpoB mutations. Codon 531 and 526 of the rpoB are the most common sites of nucleotide substitutions. 72.5% of 40 SM-resistant (SMr) isolates had an identical mutation at codon 43 of the rpsL gene. No isolates had a mutation at codon 88 of the rpsL. Only 7.5% of these SMr isolates had A-to-C transversions at position 513 of the rrs gene. Of 34 INH-resistant (INHr) isolates, 11.8% had complete katG deletions, 55.9% had mutations in the selected region of katG. Only 8.8% had alterations in the inhA regulatory sequences. 60.9% of RFPr, INHr, and SMr isolates had mutations in genetic markers for these drug resistance. CONCLUSIONS: Most drug resistance in M. tuberculosis was due to simple mutations occurring in chromosomally encoded genes. Alterations in rpoB, rpsL and katG gene may be the important mechanism of M. tuberculosis resistance to RFP, SM, and INH. PCR, PCR-SSCP, PCR-NS, and PCR-RFLP are going to become the simple, rapid and reliable diagnostic tests for drug resistance in M. tuberculosis.

Antitubercular Agents↗
PubMed1999

The diagnostic criteria for classic parasystole.

OBJECTIVE: To establish a diagnostic criteria of parasystole with high sensitivity and high specificity. METHODS: After excluded from nonparasystole and each variant parasystoles, based on the electrocardiographic data obtained from 61 patients with classic parasystole, we selected the quantitative indices which could reflect the features of ectopic focus with complete entrance block as the diagnostic criteria for parasystole. RESULTS: The common features of the electrocardiograms of this group were: 1) Take the earliest recorded eight interectopic intervals in which at least four intervals containing sinus beats or other beats having activated to the area within the ectopic focus. When in case of deficiency, it will fill up a vacancy in order. The ratios of the shortest coupling interval to the shortest ectopic cycle length (ECL) were all less than 80%; 2) The coefficients of variation of the eight ECLs were all less than 6%; 3) The maximal differences of coupling intervals were all equal to or more than 0.11 second. CONCLUSION: Three quantitative indices as necessary conditions have been used as diagnostic criteria for parasystole with high sensitivity and high specificity.

Electrocardiography↗
PubMed1999

[High-level expression of Mycobacterium tuberculosis 16,000 antigen in E. coli].

OBJECTIVE: To gain the recombinant protein antigen 16,000 of Mycobacterium tuberculosis highly expressed in E. coli and study its immunological characteristics. METHODS: DNA fragments code for the protein were obtained by PCR, then cloned into the pET plasmid vector to gain recombinant E. coli. Cells were cultured and induced to produce recombinant protein, whose molecular size and present form were analyzed by SDS-PAGE, and its immunological characteristics were analyzed by Western-blotting and ELISA technology. RESULTS: The clone was analyzed at the nucleotide lever and shown the same DNA sequence coding for natural 16,000 protein. Analyzed by SDS-PAGE and Western-blotting, it was found to produce immunoreactive proteins with mobilities very similar to those of the 16,000 protein antigen, and the recombinant protein amounted to 40% of total cell proteins. ELISA results indicated that the purified recombinant protein could distinguish sera from tuberculosis patients with anti-PPD antibody and those from tuberculin positive contacts. CONCLUSIONS: Recombinant 16,000 protein antigen highly expressed in the form of solution in E. coli was gained and this antigen was located in cell plasma. This recombinant protein showed specific immunogenicity.

Antigens, Bacterial↗
PubMed1999

[Identification of postoperative M. chelonae infection outbreak by polymerase chain reaction of 16s-23s ribosomal DNA spacer sequence].

OBJECTIVE: To determine the pathogen of the infection outbreak in a hospital in Shenzhen at gene level with molecular biological technique, and to establish a rapid identification method of M. chelonae subsp. abscessus by polymerase chain reaction technique. METHODS: A single pair of primers and oligonucleotides probe of M. chelonae subsp. abscessus were designed, according to the sequence of mycobacterium of 16s-23s ribosomal DNA spacer sequences. 53 clinical strains were amplified by polymerase chain reaction, then dot-blot hybridization of PCR product was made. On the basis of this study, 259 lesion, tissue and normal tissue were amplified by 16s-23s rDNA PCR. RESULTS: 380 bp PCR product for 53 clinical strains was yielded by 16s-23s rDNA PCR, in the meantime, the specific hybridization dot appeared. The PCR positive rate of 259 specimens was 60.6%. CONCLUSIONS: The PCR products and dot-blot hybridization showed that the pathogen of the infection outbreak was M. chelonae subsp. abscessus at gene level. The 16s-23s rDNA PCR investigative system is sensitive and specific, which can identify M. chelonae subsp. abscessus.

DNA, Ribosomal Spacer↗
PubMed1999

[Clinical study on tangshen mixture in treating diabetic nephropathy].

OBJECTIVE: To investigate the effects of Tangshen Mixture (TSM) on the serum glucose, quantity of proteinuria per 24 h, hypercoagulative status and oxidative injury in patients with diabetic nephropathy (DN). METHODS: Ninety-three patients with DN were randomly divided into treated group and control group. 48 patients in the former were treated with insulin and TSM, while the latter was treated with insulin alone. Before and after treatment, the levels of fasting blood glucose (FBG), 2 h after meal blood glucose (PBG), 24 h urinary albumin (24 h-pro), endothelin (ET), alpha-granule membrane glycoprotein-140 (GMP-140), erythrocyte superoxide dismutase (ESOD), lipid peroxidase (LPO) were measured. RESULTS: After two months treatment, compared with the control group the levels of ET and GMP-140, LPO, and 24 h-pro lowered obviously (P < 0.01, P < 0.05), and the level of ESOD increased (P < 0.05) in the treated group, no obvious change was found in control grout after treatment. CONCLUSION: TSM could improve the hypercoagulative status, alleviate the renal free radical disturbances, and reduce the urinary protein loss.

Adult↗
PubMed1999

[The 38,000 protein of Mycobacterium tuberculosis is overexpressed in Escherichia coli].

OBJECTIVE: To obtain recombinant 38,000 protein in large quantities and to study its immunologic characteristics by stable expression of the gene encoding for 38,000 antigen of Mycobacterium tuberculosis in E. coli. METHODS: Expression plasmid was constructed with DNA recombinant technique. Positive clones were screened using double digestion and polymerase chain reaction. Recombinant plasmid was transformed into E. coli. Then E. coli carrying recombinant plasmid were induced. The expression of 38,000 antigen was identified by SDS-polyacrylamid gel electrophoresis (PAGE) and immunoblotting. Stained gel was scanned to detect expression level of recombinant antigen. RESULTS: Gel stained with coomassie blue G-250 showed that the induced E. coli carrying recombinant plasmid can produce 38,000 protein at high level. Gel scan showed that 38,000 antigen expression in E. coli was about 36% - 40% of total cellular protein. The recombinant 38,000 antigen existed mostly in inclusion bodies. The recombinant antigen can react with antibodies: serum of pulmonary tuberculosis patients and the goats immuned with Mycobacterium tuberculosis. CONCLUSIONS: Constructed recombinant E. coli can overproduce 38,000 antigen of Mycobacterium tuberculosis. Inclusion bodies are easy to purify and can protect the recombinant antigen from protease, on the other hand, it has not biological activity unless the denatured protein is accurately folded.

Antigens, Bacterial↗
PubMed1999

[A clinical study on vaccine of Mycobacterium vaccae in treating pulmonary tuberculosis].

OBJECTIVE: To study the effect of vaccine of Mycobacterium vaccae on cell-mediated immunity and on treating patients with pulmonary tuberculosis. METHODS: Seventy cases of pulmonary tuberculosis with smear positive and initial treatment were classified randomly into group I (35 cases) and group II (35 cases), receiving 2HRZS/4HR and 2HRZS/4HR plus vaccine of Mycobacterium vaccae regimens respectively. Thirty-one multi-drug resistant pulmonary tuberculosis cases were classified into group III, receiving 4 - 6 sensitive antituberculous drugs and vaccine of Mycobacterium vaccae. Improvement of clinical symptoms, resolution of pulmonary lesions, negative conversion of sputum and changes of immunological functions were observed. RESULTS: No significant difference in improvement of symptoms was found in group I and group II (P > 0.05), and the improvement rate of clinical symptoms in group III was found more than 50%. X-ray resolution rates in 4th month were 83% and 89%, and cavity reducing rates 40% and 50% respectively in group I and group II, and no significant differences were found (P > 0.05). X-ray resolution rate was 29%, cavity reducing rate 7% and no deteriorated case was found in group III. Sputum negative conversion rates in 1st, 2nd, 3rd and 4th month were 23%, 51%, 83% and 97% respectively in group I, while 31%, 77%, 89% and 100% in group II, and 3%, 16%, 29% and 32% in group III. Significant difference was found between group I and group II in sputum negative conversion rate in 2nd month after treatment (P < 0.05). After treatment, values of lymphocyte transformation test (LTT), CD(3), CD(4) and CD(4)/CD(8) of the above 3 groups were all higher than that before the treatment (P < 0.05), level of tumor necrosis factor decreased in group II and IL-2, IL-6 increased in group III. CONCLUSIONS: Vaccine of Mycobacterium vaccae is a good immunotherapy preparation, which promotes sputum negative conversion and activation of cell-mediated immunity.

Adolescent↗
PubMed1999

[Safety analysis of dust mite allergen for diagnosis and immunotherapy of asthma and rhinitis].

AIM: To make a retrieval investigation of safety in using Dermatophagoides farinae extract in diagnosis and immunotherapy with patients of asthma and rhinitis. METHODS: A questionnaire evaluation of the safety use of D. farinae extract (SMU-Df) during diagnosis and immunotherapy of patients from 1974 to 1995 was carried out. RESULTS: A total of 8,46,342 injections were statistically analysed, among whom 142 systemic adverse reactions occurred involving urticaria 0.82@10000, severe attack of asthma 0.77@10000, anaphylactic shock 0.07@10000 (CL = 1.4-12.0/million), and angioedma 0.02@10000. The time of onset of systemic reactions of immediate type was < 30 min in 32 cases-times, and 1 h and 2 h in 6 cases-times; the time to onset of late response type was 3 h-48 h in 23 cases-times with highest incidence of severe asthmatic attacks. The systemic reactions occurred in 18 subjects during skin test, in 96 cases-times during increasing dose phase, and in 14 cases-times during. Among them 6 cases were of anaphylactic shock, and none of it after emergency treatment. The major cause of manifestation of systemic reactions for 41 cases after immunotherapy with SMU-Df extract was due to over dosage errors. CONCLUSION: The application of SMU-Df extract in skin test and immunotherapy of asthma and rhinitis sensitive to mite for the past 22 years in this country indicated that the efficacy and safety have been high.

Allergens↗
PubMed1998

Synthesis of novel oximes of 2-aryl-6-methoxy-3,4-dihydronaphthalene and their evaluation as inhibitors of 17 alpha-hydroxylase-C17,20-lyase (P450 17).

The synthesis and biological evaluation of oximes of 2-aryl-6-methoxy-3,4-dihydronaphthalene (7a, 7b, 14a, 14b) as nonsteroidal inhibitors of 17 alpha-hydroxylase-C17,20-lyase (P450 17, CYP 17) is described. The target compounds were synthesized and identified by 1H NMR and MS. The preparation of the key intermediates 5a and 5b was accomplished by coupling 4a and 4b with 1 (2-hydroxy-6-methoxy-3,4-dihydronaphthalene-2-trifluoromethanesulfonate) using the palladium complex Pd(PPh3)4 as catalyst. Hydrolysis of 5a and 5b in THF-HCl solution at room temperature gave the corresponding keto compounds 6a and 6b. The other important intermediates--the substituted (E)-2-methyl-ene-1-tetralones 10a and 10b--were obtained by condensation of 1-tetralone with the corresponding aromatic aldehydes (9a and 9b). Hydrogenation (H2), followed by reduction (NaBH4), and subsequent hydrolysis and elimination led to the keto compounds 13a and 13b. The title compounds, the oximes 7a, 7b and 14a, 14b were formed by reaction of hydroxylamine hydrochloride with the corresponding keto compounds. Using a microsomal fraction of human testicular enzyme, 7a, 7b, 14a, and 14b inhibited the target enzyme only marginally.

Enzyme Inhibitors↗
PubMed1998

Functional replacement of the mouse E2A gene with a human HEB cDNA.

The mammalian E2A, HEB, and E2-2 genes encode a unique class of basic helix-loop-helix (bHLH) transcription factors that are evolutionarily conserved and essential for embryonic and postnatal development. While the structural and functional similarities among the gene products are well demonstrated, it is not clear why deletion of E2A, but not HEB or E2-2, leads to a complete arrest in B-lymphocyte development. To understand the molecular basis of the functional specificity between E2A and HEB/E2-2 in mammalian development, we generated and tested a panel of E2A knockin mutations including subtle mutations in the E12 and E47 exons and substitution of both E12 and E47 exons with a human HEB cDNA. We find that the alternatively spliced E12 and E47 bHLH proteins of the E2A gene play similar and additive roles in supporting B lymphopoiesis. Further, we find that HEB driven by the endogenous E2A promoter can functionally replace E2A in supporting B-cell commitment and differentiation toward completion. Finally, the postnatal lethality associated with E2A disruption is fully rescued by the addition of HEB. This study suggests that the functional divergence among E12, E47, and HEB in different cell types is partially defined by the context of gene expression.

Alleles↗
PubMed1998

[The relationship of insulin resistance and the pathogenesis and perinatal outcome of pregnancy induced hypertension].

OBJECTIVE: To study the insulin resistance in the pathogenesis of pregnancy induced hypertension (PIH), and its relationship to perinatal outcome. METHODS: In 111 PIH and 155 control group, the concentration of C peptide and insulin of maternal blood samples before and after 32 gestational weeks, and fetal blood samples just after delivery was determined. Fetal outcomes were assessed by the neonatal weight at delivery, Apgar scores and the quality and quantity of amniotic fluid. RESULTS: The maternal concentration of C peptide and insulin in PIH was higher than that of control group (P < 0.05, or P < 0.01). In PIH group, the maternal concentration of C peptide and insulin in the subgroup of adverse perinatal outcomes tended to be higher than that in the subgroup of good perinatal outcomes; but in control group, there was no significantly difference between these two subgroups. CONCLUSIONS: Insulin resistance may be one of the factors which couse PIH, and it has significant relationship with advese perinatal outcomes.

Adult↗
PubMed1998

[Study on the karyotype and recurrence risk of malformed newborns].

OBJECTIVE: To survey the karyotype and recurrence risk of malformed newborns. METHODS: Karyotypes of 104 malformed newborns were analyzed using G-banding. All cases were devided into two groups depending on their karyotypes: Group 1 with normal karyotype (n = 51) and group 2 with abnormal (n = 53). Clinical data were compared between malformed groups and control. Women who had the second babies after delivering a malformed (n = 20) were included in the statistics of recurrence risk. RESULTS: (1) Of 104 cases, 53 had abnormal karyotype (50.96%). They were trisomy 21, trisomy 18, 45X, 1q+ and 5p+ (n = 41, 9, 1, 1, 1, seperately). (2) Within group 2, women's mean delivery age was elder, while premature delivery rate was higher than that of control (P < 0.01, 0.05). In group 1, the proportion of women with abnormal pregnancy history increased as compared with control (P < 0.05). The rate of fetal distress, poly/oligohydramnios and small for gestational age (SGA) of two malformed groups was higher apparently than that of control. The birth weight of two malformed groups declined obviously. (3) Within 20 second babies being born after their malformed siblings, 6 were malformed too. The total recurrence rate was 30%. CONCLUSION: (1) Abnormal karyotype is an important cause of congenital malformations; (2) The age pregnant women abnormal pregnancy history, IUGR and poly/oligohydramnios all may be the high risk factors of congenital malformations; (3) The recurrence rate of malformations rises after the first malformed newborn's birth.

Chromosomes, Human, Pair 18↗
PubMed1998

[A study of maternal and fetal peroxidation in elderly primigravidea].

OBJECTIVE: To analyze the rlationship between the age of pregnant women and maternal and fetal peroxidation. METHODS: Pregnant 164 women in their third trimester were collected and divided into 3 groups according to maternal ages: in group 1, maternal age less than 35, n = 71; group 2, maternal age 35-39, n = 63; group 3, 40 or over, n = 30. All the women had no other high risk factors. Maternal and umbilical blood samples were drawn during delivery, and the concentration of superoxide enzyme (SOD) and Lipid peroxidate produce (LPO) were determined. RESULTS: There were no significant differences in neonatal Apgar scores, birth weight, and the volume and quality of amniotic fluid among the 3 groups, but the cesarean scetion rate increased along with maternal age. The fetal SOD concentration was significantly higher than that in maternal serum, but the LPO level was lower. There was significant correlation between maternal age and maternal serum SOD and LPO levels (r1 = 0.15, P < 0.05; r2 = 0.2299, P < 0.01). The maternal LPO levels in group 2 and 3 were significantly higher than that in group1 (P < 0.05), and the concentration of SOD in group 3 was significantly lower than that in group 1 (P < 0.05). CONCLUSION: The activity and concentration of free radicals were higher in mother than that in fetus, and the ability of anti-oxidation was lower in mother. The maternal age is associated with SOD and LPO levels during pregnancy.

Adult↗
PubMed1998

[Studies on mutation of rifampicin-resistant genes in M. tuberculosis].

OBJECTIVE: To understand mutation of rifampicin-resistant genes in M. tuberculosis clinical isolates, and to develop a new method for detecting drug resistance. METHOD: Analyzing the rpoB genes in 50 M. tuberculosis clinical isolates with polymerase chain reaction-single-stranded conformation polymorphism (PCR-SS-CP) and PCR-direct sequencing(PCR-DS) techniques. M. tuberculosis strain H37Rv was used as control. RESULT: Of 3 drug-sensitive isolates and 2 non-rifampicin-resistant isolates selected, only 1 drug-sensitive isolate with abnormal rpoB SSCP profile had TCG-->TTG mutation at codon 531. Of 45 rifampicin-resistant isolates, 35 isolates with abnormal SSCP profiles had mutations in rpoB sequences, in which 14 isolates displayed TCG-->TTG or TGG or TAC mutations at codon 531, 14 had CAC-->TAC or GAC or CCC or CTC or GTC mutations at codon 526, 2 had GAC-->GTC or TAC mutations at codon 516, 2 had two point mutations, and 3 had different rpoB sequences from that of M. tuberculosis. CONCLUSION: Resistance to rifampicin in most M. tuberculosis isolates is due to the mutations on the genes encoding the RNA polymerase subunit (rpoB). PCR-SSCP and PCR-DS techniques might become simple, rapid and reliable diagnostic tests for rifampicin resistance in clinical isolates.

Antitubercular Agents↗
PubMed1998

[Effect of Salvia Miltiorrhiza injection on umbilical artery hemodynamics during fetal distress in ewe].

OBJECTIVE: To study the effect of Salvia Miltiorrhiza injection (SMI) on umbilical artery hemodynamics during fetal distress in ewe. METHODS: Intrauterine surgery were performed at 116-125 gestational days in 3 pregnancy sheep for insertion of vascular catheters at abdominal aorta from femoral artery and for implantation of a electromagnetic flowmetre probe around umbilical artery. Gelatin microsphere injection to abdominal aorta through vascular catheter for obstruction of placental-fetal circulation. 2 ml of SMI was used 6 times(2 times each sheep), and the signs of umbilical artery blood flow and wave forms of fetal abdominal aorta blood pressure were recorded before and after injections of gelatin microsphere or SMI. The fast Fourier translation (FFT) was used to turn signs in time domain into powers spectral of input impedance in frequency domain for resistance and characteristic impedance of umbilical artery. RESULTS: After the SMI was injected into fetal abdominal aorta, the resistance of umbilical artery was significantly reduced (P < 0.05), and the changes of resistance was significantly relative with the resistance before SMI injected (r = -0.85, P < 0.001). But there were no significantly different impedance between before and after SMI treatment (P > 0.05). CONCLUSIONS: The SMI to fetal abdominal aorta can decrease umbilical artery blood flow resistance and the changes of resistance was significantly relative to that before SMI treatment.

Animals↗
PubMed1997

Synthesis of Z- and E-1-methyl-2-(1-hydroximinoethyl)-6-methoxy-3,4-dihydronaphthalene and evaluation as inhibitors of 17 alpha-hydroxylase-C17,20-lyase (P450 17).

The synthesis and biological evaluation of Z- and E-1-methyl-2-(1-hydroximinoethyl)-6-methoxy-3,4-dihydro-naphtha len e (Z-1 and E-1) as nonsteroidal inhibitors of 17 alpha-hydroxylase-C17,20-lyase (P450 17, CYP 17) is described. Z-1 and E-1 were separated by column chromatography and identified by 1H NMR. The synthesis of the key compound 3 was accomplished by a new reaction acetylating the 1-methyl-6-methoxy-3,4-dihydronaphthalene compound 2 under Friedel-Crafts conditions. Compound 2 was obtained from the 1-tetralone via Wittig reaction. Using a microsomal fraction of human testicular enzyme, Z-1 and E-1 inhibited the target enzyme only marginally.

Enzyme Inhibitors↗