Biomedical subjects

Y M Zhang

Publications and source records attributed to Y M Zhang.

At least 37 records · Page 2Linked to original sources

PubMed2001

Distribution of angiotensin converting enzyme gene polymorphism among Northern Hans, Dahurs, and Ewenks.

AIM: To observe the polymorphism of angiotensin-converting enzyme (ACE) gene in Northern Hans, Dahurs, and Ewenkis of China. METHODS: The polymerase chain reaction was used to type the insertion/deletion polymorphism at intron 16 of ACE gene among 90 Northern Hans, 84 Dahurs, and 64 Ewenkis individuals. The experiment displayed the distribution in three kinds of ACE genotype: ID (heterozygotes of insertion and deletion), DD (homozygotes of deletion), and II (homozytes of insertion). RESULTS: In Northern Hans the percentages of the distributing ACE I/D genotype were ID 27.8 %, DD 17.8 %, and II 54.4 %. The I/D genotype frequency of Dahurs individuals were ID 60.7 %, DD 26.2 %, and II 13.1 %. The Ewenkis genotype frequency were ID 70.3 %, DD 21.9 %, and II 7.8 %. CONCLUSION: The polymorphism of ACE gene of Northern Hans is different from that of Dahurs and Ewenkis in China.

Asian People↗

PubMed2001

[Determination of puerarin in xinmaitong oral liquid by HPLC].

OBJECTIVE: To develop a method to determine the content of puerarin in Xinmaitong oral liquid. METHODS: HPLC method was used. The separation was performed on Suntek kromasil C18 column with methanol-water containing 0.5% acetic acid (25:75) as a mobile phase and the wavelength of UV detector was 250 nm. RESULTS: The linearity of puerarin was good and average recovery was 97.8%. CONCLUSION: The method is simple, reliable and sensitive. It also shows good resolation. It can be used in quality control of Xinmaitong oral liquid.

Administration, Oral↗

PubMed2001

[Influences of age and gender on dose-response and recovery time-course of atracurium].

OBJECTIVES: To evaluate the influences of age and sex on dose-response and recovery time course of atracurium. METHODS: Seventy-two patients (38 men and 34 women), ASA grade I, aged 15-59 years, scheduled for elective surgery were included in the study. All patients were divided into three groups according to their ages: Group 1, 32 patients aged 15-29 years; Group 2, 21 patients aged 30-40 years, and Group 3, 19 patients aged 41-59 years. General anesthesia was maintained with 60% nitrous oxide in oxygen, thiopentone and fentanyl. Neuromuscular function was assessed by train-of-four(TOF) stimulation of accelerometry and the percentage depression of the first response (T1) of the TOF stimulus was used as the study parameter. The dose-response relations of atracurium were determined by the cumulative dose-response technique. RESULTS: As compared to older and female patients, dose-response curves of atracurium in young and male patients were shifted in a parallel fashion to the left. The dose-response relation of atracurium correlated closely with patients' ages and sexes by multiple linear regression analysis. There were significant differences of ED50, ED90 and ED95, and clinical duration and total duration of action following administration of atracurium of same doses between the three age groups as well as men and women. CONCLUSIONS: Age and gender could significantly affect the pharmacodynamics of atracurium.

Adolescent↗

PubMed2001

[Stimulatory effect of chemokine-like factor 1 (CKLF1) on the growth of bone marrow cells].

OBJECTIVE: To investigate the activity of CKLF1 on the proliferation and differentiation of bone marrow cells. METHODS: Human low density bone marrow cells and mouse bone marrow cells were plated in 96-well microplate and supernatants from transfected COS-7 cell culture were added. The cell proliferation was assayed by MTT method after 5 days incubation. The enhancing effect of CKLF1 on the colony formation of human hematopoietic progenitor cells was identified in semi-solid culture. RESULTS: CKLF1 has obvious enhancing effect on both human and mouse bone marrow cells, it can stimulate the colony formation of human hematopoietic stem cells and has synergistic action with GM-CSF. CONCLUSION: CKLF1 can promote the proliferation and differentiation of bone marrow cells.

Animals↗

PubMed2001

[Eukaryotic expression and in vitro tumor cell apoptosis-induced effect of human TRAIL].

OBJECTIVE: To explore the tumor cell apoptosis induced by the effect in vitro of eukaryotic expression of full-length TRAIL cDNA and its extracellular region. METHODS: The eukaryotic expression vectors for both forms of the cDNA acquired from the fetal heart cDNA library were constructed. After gene transfecting, the stable expression cell lines were obtained by G418 screening. RESULTS: The supernatants from tansfectants could induce apoptosis of different tumor cell lines in vitro, and an enhanced effect was observed by adding TFAR19 (TF-1 cell apoptosis-related protein 19), a novel apoptosis gene product discovered in our laboratory. CONCLUSION: Eukaryotic expression products of TRAIL can induce apoptosis of the tumor cells, and TFAR19 could enhance the effect on apoptosis of tumor cells.

Animals↗

PubMed2000

Identification and analysis of the acyl carrier protein (ACP) docking site on beta-ketoacyl-ACP synthase III.

The molecular details that govern the specific interactions between acyl carrier protein (ACP) and the enzymes of fatty acid biosynthesis are unknown. We investigated the mechanism of ACP-protein interactions using a computational analysis to dock the NMR structure of ACP with the crystal structure of beta-ketoacyl-ACP synthase III (FabH) and experimentally tested the model by the biochemical analysis of FabH mutants. The activities of the mutants were assessed using both an ACP-dependent and an ACP-independent assay. The ACP interaction surface was defined by mutations that compromised FabH activity in the ACP-dependent assay but had no effect in the ACP-independent assay. ACP docked to a positively charged/hydrophobic patch adjacent to the active site tunnel on FabH, which included a conserved arginine (Arg-249) that was required for ACP docking. Kinetic analysis and direct binding studies between FabH and ACP confirmed the identification of Arg-249 as critical for FabH-ACP interaction. Our experiments reveal the significance of the positively charged/hydrophobic patch located adjacent to the active site cavities of the fatty acid biosynthesis enzymes and the high degree of sequence conservation in helix II of ACP across species.

3-Oxoacyl-(Acyl-Carrier-Protein) Synthase↗

PubMed2000

Influence of different chelators (HYNIC, MAG3 and DTPA) on tumor cell accumulation and mouse biodistribution of technetium-99m labeled to antisense DNA.

We have shown recently that cell accumulation in culture of antisense DNA is strongly influenced by the presence of a 99mTc-MAG3 group for radiolabeling. We have now compared the in vitro and mouse in vivo behavior of 99mTc when radiolabeled to one antisense phosphorothioate DNA by three different methods. The 18-mer antisense DNA against the RIalpha subunit of PKA was conjugated via a primary amine on the 5'-end with the NHS esters of HYNIC and MAG3 and by the cyclic anhydride of DTPA. Surface plasmon resonance measurements revealed that the association rate constant for hybridization was unchanged for all three chelators as compared with that of the native DNA. Size exclusion HPLC showed rapid and quantitative protein binding for all three chelators upon incubation of labeled DNAs in 37 degrees C serum and cell culture medium. However, in each case, radiolabeled and intact oligonucleotide was still detectable after 24 h. Cellular uptake was tested in an RIalpha mRNA-positive cancer cell line. The order of cellular accumulation of 99mTc was DTPA>HYNIC(tricine) >MAG3, with the differences increasing with time between 4 and 24 h. The rate of 99mTc egress from cells was found to be MAG3>HYNIC>DTPA, which may explain the order of cellular accumulation. The biodistribution in normal mice was heavily influenced by the labeling method and followed a pattern similar to that seen previously by us for peptides labeled with the same chelators. In conclusion, although these studies concerned only one antisense DNA in one cell line, the results suggest that the success of antisense imaging may depend, in part, on the method of radiolabeling.

Animals↗

PubMed2000

Differential temporal coding of the vibratory sense in the hand and foot in man.

OBJECTIVE: We studied the difference in the temporal tuning function of the vibratory senses between the hand and foot in man by using steady-state somatosensory evoked potentials (S-SEPs) to vibratory stimulation. METHODS: Vibratory stimuli were applied to the palm and sole, and the S-SEPs were then recorded in 8 normal subjects. A total of 200 responses were recorded from 4 electrodes including the ipsi-and contralateral somatosensory areas of the hand and foot. The amplitude of the first harmonic component (1F) was obtained by a Fourier analysis. The effect of modulation frequency (17-30 Hz) on the 1F at a stimulus intensity of 0.05 N was studied. RESULTS: The amplitudes of the S-SEPs were the greatest in the contralateral hand and foot areas. The mean 1F amplitudes of the palm S-SEPs as a function of the modulation frequency showed a narrow tuning curve with a peak near 21 Hz while those of the sole demonstrated a broad tuning curve. CONCLUSION: Our results suggest the differential temporal coding of the vibratory sense in the hand and foot areas of the somatosensory cortex in man. This is probably caused by the different characteristics in the receptors situated in the hand and foot.

Adolescent↗

PubMed2000

Influence of acute normovolaemic haemodilution on the dose-response and time-course of action of atracurium.

BACKGROUND: Acute normovolaemic haemodilution is a common method to save and avoid homologous blood transfusion during surgery. The aim of this study was to evaluate the influence of acute isovolaemic haemodilution on the dose-response and time-course of action of atracurium. METHODS: We studied 25 patients undergoing acute isovolaemic haemodilution during surgery and 25 patients not receiving haemodilution as a control group. All patients were ASA grade I and aged 18-54 yr. The haemodilution patients underwent major elective plastic surgery with an anticipated surgical blood loss of more than 600 ml, and the control patients underwent elective superficial plastic surgery with an anticipated surgical blood loss of less than 200 ml. Anaesthesia was induced with thiopental 4-6 mg/kg and fentanyl 2-4 microg/kg i.v., and maintained with 60% nitrous oxide in oxygen. After stabilization of anaesthesia, acute isovolaemic haemodilution in the haemodilution group was achieved by drainage of venous blood and an i.v. infusion of lactated Ringer's solution, and 6% dextran, during which haematocrit and haemoglobin decreased from 45.1% to 25.8% and from 147.2 g/l to 91.2 g/l, respectively. When anaesthesia was stable in the control group and haemodilution was completed in the haemodilution group, neuromuscular function was assessed by measuring with accelerography the response of the adductor pollicis muscle to supramaximal train-of-four (TOF) stimuli every 12 s to the ulnar nerve at the wrist via surface electrodes. The dose-response relationships of atracurium in the two groups were determined by the cumulative dose-response technique. RESULTS: The results showed that during haemodilution, the dose-response curve of atracurium was shifted to the left in a parallel fashion and the potency of atracurium was increased. In patients undergoing haemodilution, ED50, ED90 and ED95 of atracurium were decreased by 25-33%, and duration of action was increased by 21-48% following administration of the same dose (mg/kg), as compared with patients not undergoing haemodilution. CONCLUSION: We concluded that the patients undergoing acute isovolaemic haemodilution were about 30% more sensitive to neuromuscular blockade of atracurium and had a longer duration after administration of the same dose (microg/kg) than the control patients. Care must be taken with this problem when atracurium is used as a muscle relaxant during acute haemodilution.

Adolescent↗

PubMed2000

Clinical value of [18-F]] fluorodeoxyglucose positron emission tomography imaging in soft tissue sarcomas.

OBJECTIVE: To evaluate positron emission tomography (PET) using 2-fluoro-2-deoxy-D-glucose (FDG) for clinical application in soft tissue sarcomas. SUMMARY AND BACKGROUND DATA: FDG PET is a promising noninvasive method for the preoperative assessment of soft tissue sarcomas and may complement radiologic tomography. METHODS: Data from 50 consecutive patients with 59 masses, either suspicious for primary or locally recurrent soft tissue sarcoma, were prospectively gathered. The semiquantitative FDG uptake (standardized uptake values [SUVs]) was calculated in tumor and normal tissue (muscle). Histopathology of surgical specimens and follow-up data were used as control criteria. RESULTS: In primary soft tissue sarcomas, PET displayed a sensitivity of 91% and a specificity of 88%. Local recurrence was detected with a sensitivity of 88% and a specificity of 92%. All intermediate-grade and high-grade soft tissue sarcomas (primary and locally recurrent) were visualized with a precise differentiation from muscle. Fifty percent of the low-grade sarcomas showed an FDG uptake equivalent to muscle (false-negative results in one primary and three recurrent soft tissue sarcomas). Benign soft tissue tumors (e.g., lipoma, leiomyoma, ganglion) did not accumulate FDG. Inflammation resulted in an increased FDG uptake. The semiquantitative FDG uptake (SUVs) correlated with tumor grade but not with size and histologic type. CONCLUSION: High-grade and intermediate-grade soft tissue sarcomas are amenable to PET imaging, whereas low-grade lesions may not be depicted. SUVs for FDG correlate with tumor grade in soft tissue sarcomas. Benign soft tissue tumors are differentiated from higher-grade soft tissue sarcomas. These data show that FDG-PET can complement preoperative radiologic assessment for soft tissue sarcomas and that FDG-PET is a powerful diagnostic tool for detecting high-grade and intermediate-grade local recurrence.

Adolescent↗

PubMed2000

Induction of a futile Embden-Meyerhof-Parnas pathway in Deinococcus radiodurans by Mn: possible role of the pentose phosphate pathway in cell survival.

Statistical models were used to predict the effects of tryptone, glucose, yeast extract (TGY) and Mn on biomass formation of the highly radioresistant bacterium Deinococcus radiodurans. Results suggested that glucose had marginal effect on biomass buildup, but Mn was a significant factor for biomass formation. Mn also facilitated glucose interactions with other nutrient components. These predictions were verified by in vivo and in vitro experiments. TGY-grown cells metabolized glucose solely by the pentose phosphate pathway (PPP). Although only a fraction of glucose from the medium was transported into the cells, glucose was incorporated into the DNA efficiently after cells were exposed to UV light. The presence of glucose also enhanced the radioresistance of the culture. Mn could induce an Embden-Meyerhof-Parnas (EMP) pathway in D. radiodurans. The EMP pathway and the PPP of the Mn-treated cells oxidized glucose simultaneously at a 6:1 ratio. Although glucose was hydrolyzed rapidly by the Mn-treated cells, most glucose was released as CO(2). Mn-treated cultures retained less glucose per cell than cells grown without Mn, and still less glucose was incorporated into the DNA after cells were exposed to UV light. Mn-treated cells were also more sensitive to UV light. Results suggested that metabolites of glucose generated from the PPP enhanced the survival of D. radiodurans. Induction of the EMP pathway by Mn may deplete metabolites for DNA repair and may induce oxidative stress for the cell, leading to reduction of radioresistance.

Biomass↗

PubMed2000

High-level resistance to 3'-azido-3'-deoxythimidine due to a deletion in the reverse transcriptase gene of human immunodeficiency virus type 1.

A variant of human immunodeficiency virus type 1 (HIV-1) possessing a deletion in the reverse transcriptase (RT) gene at codon 67 was identified in a patient who had failed combination antiretroviral therapy. This deletion initially emerged under the selective pressure of combination therapy with 3'-azido-3'-deoxythymidine (AZT) plus 2',3'-dideoxyinosine. It has persisted for more than 3 years in association with the accumulation of a variety of other well-described drug resistance mutations and an uncharacterized mutation at RT codon 69 (T69G). Phenotypic studies demonstrated that the codon 67 deletion by itself had little effect on AZT sensitivity. However, in the context of the T69G mutation and three other mutations known to be associated with AZT resistance (K70R, T215F, and K219Q), this deletion led to a increase in AZT resistance from 8. 5-fold to 445-fold. A further increase in resistance (up to 1, 813-fold) was observed when two mutations associated with nonnucleoside RT inhibitor resistance (K103N and L74I) were added to the deletion T69G K70R T215F K219Q construct. Hence, these results establish that a deletion at RT codon 67 may be selected for in the presence of antiretroviral therapy and may lead to high-level resistance to AZT.

Anti-HIV Agents↗

PubMed2000

Resistance to replication of human immunodeficiency virus challenge in SCID-Hu mice engrafted with peripheral blood mononuclear cells of nonprogressors is mediated by CD8(+) T cells and associated with a proliferative response to p24 antigen.

High levels of resistance to challenge with human immunodeficiency virus type 1 SF162 were observed in animals engrafted with peripheral blood mononuclear cells of four long-term nonprogressors (LTNPs). Resistance was abrogated by depletion of CD8(+) T cells in vivo and was observed only in LTNPs with proliferative responses to p24. In a subgroup of nonprogressors, CD8(+) T cells mediated restriction of challenge viruses, and this response was associated with strong proliferative responses to p24 antigen.

Animals↗

PubMed2000

[Expression and roles of hemoglobin gene in Bacillus subtilis].

Hemoglobin of the Gram-negative bacterium Vitreoscilla can bind oxygen strongly and reduce the oxygen requirement of the bacterium. A recombinant plasmid pAV was constructed by inserting the hemoglobin gene (Vgb) to the downstream of the promoter of beta-lactase gene of the B. subtilis plasmid pAK4. The plasmid pAV was transferred into strain DB104, G331 (a subtilisin-producing B. subtilis) and B53 (a xylanase-producing B. subtilis). The subclones and transfer of the Vgb gene into pAK4 were detected and confirmed by Dot blotting and electrophoresis analysis. The expression of homoglobin was measured by recording CO-difference spectra after bubbling CO into the sample cuvette. The production of subtilisin and xylanase was increased in the fermentation of the Vgb-expressing strains. These results provided a new way to reduce the oxygen requirement and to increase the biomass production in the fermentation industry.

Bacillus subtilis↗

PubMed2000

[Tissue culture induced translocation conferring powdery mildew resistance between wheat and Dasypyrum villosum and its marker-assisted selection].

Glutamate oxaloacetate transaminase (GOT) electrophoretic analyses were performed in 175 regenerants arising from immature embryos of crosses between wheat (Triticum aestivum L.) and 6D/6V substitution stocks. The GOT-V2 coding specific enzyme band was absent in two regenerants, designated 98R149 and 98R159 respectively, originated from cross of Yi 4095 and 6D/6V substitution stock c.v. RW15. Pm21 gene linked SCARs (Sequence Characterized Amplified Regions) analysis indicated that 6VS chromosome arms existed in 98R149 and 98R159. Fluorescence in situ hybridization with total genomic DNA extracted from Dasypyrum villosum (L.) as a probe confirmed the occurrence of translocation between 6V chromosome and a wheat one in the two regenerants mentioned above. 98R149 and 98R159 were immune to powdery mildew (Erysiphe graminisDC. f. sp. tritici) inoculation with mix races collected from Hebei Province. The results of the present paper added another feasible example of useful translocations via tissue culture.

Aspartate Aminotransferases↗

PubMed2000

[Identification of mixed major genes and polygenes inheritance model of quantitative traits by using DH or RIL population].

The accuracy of the mixed inheritance analysis of quantitative traits with larger experimental error could be improved while using DH or RIL population. The segregation analysis method of identifying mixed major genes and polygenes inheritance model, including linkage inheritance model, of quantitative traits by using DH or RIL population was developed in this paper. The method may be applied to identify the mixed major gene and polygenes inheritance model of quantitative traits, estimate genetic effects and variances of major genes and polygenes, and the recombination value while there is linkage between two major genes. Finally, an example was used to illuminate the above procedure.

Genetic Linkage↗

PubMed2000

[High efficient intergeneric chromosomal translocations between wheat (Triticum aestivum L.) and Dasypyrum villosum arising from tissue culture and irradiation].

Intergeneric chromosomal translocations were discernable both in callus cells and in regenerants arising from crosses between Triticum aestivum and T. durum-Dasypyrum villosum amphiploid c.v. TH1 and TH1W by means of fluorescence in situ hybridization. There were not only reciprocal translocations, but small fragment translocations. The results proved again the feasibility of creating intergeneric translocations via tissue culture. Irradiation facilitated numerical and structural chromosome changes in callus cells. The frequency of translocations was as high as 7.4 percent in irradiated callus cells. Callus age had an important impact on numerical and structural chromosome abnormalities. During a given time of culture, the frequency of unchanged cells was declined, while those cells with chromosome losses were inclined. The duration of culture had not significant effects on cells with chromosome gains. As structural chromosome changes is concerned, the duration of culture predominantly increased the frequency of cells with telocentric chromosomes. The chromosomal changes occurred at the initiation period of tissue culture. A number of cells which were doubled their chromosome numbers (2n = 84) were observed at a certain frequency in the period of tissue culture. These cells, however, disappeared in the successive culture.

Crosses, Genetic↗

PubMed2000

[The relationship between the change of mitochondria and the fertility in CMS line of sorghum after heat shock].

The mitochondria of anther in pollen mother cell stage of cytoplasmic male sterility (CMS) line 3197A in sorghum were extracted after heat shock. The number of the mitochondria was measured by flow cytometer and some isoenzymes were analyzed by PAGE combined with stain for enzyme activity. The result of mitochondria quantity measurement shows that the number of the mitochondria in CMS line 3197A increased greatly up to 4.5 folds after heat shock. The analysis of isoenzymes also demonstrates that the type of isoenzyme in CMS line is in consistent with maintainer line. The study denoted the change of the quantity of mitochondria after heat shock and the relationship between this change and the fertility in sorghum.

Edible Grain↗