Biomedical subjects

Z Fan

Publications and source records attributed to Z Fan.

At least 55 records · Page 3Linked to original sources

PubMed2001

An analysis of therapeutic effect of drug acupoint application in 209 cases of allergic asthma.

Both therapies of traditional crude herb moxibustion and drug acupoint application were used in 209 cases of allergic asthma to compare their long-term and short-term therapeutic effects and to analyze the relationship between clinic therapeutic effects of both therapies and differential types of the disease. The results showed that the short-term total effective rate in the group of drug acupoint application was higher than that in the group of traditional crude herb moxibustion, the therapeutic effects of drug acupoint application being closely related to differential types. Analysis also shows the best short-term therapeutic effect was in the type of heat in the lung while the poorest effect in the type of deficiency of the kidney-yang.

Acupuncture Points↗

PubMed2001

[The inhibitory effect of oxymatrine on hepatitis C virus in vitro].

OBJECTIVE: To study the inhibitory effect of oxymatrine on HCV in vitro. METHODS: SMMC-7721 cells transfected with pBK-HCV using lipofectin transfection protocal were treated with oxymatrine. bDNA signal amplification assay and MTT colorimetric assay were used for intracellular HCV RNA and cytotoxicity. RESULTS: The stable HCV expression cell model established here could be used as a tool for medicine screen. Oxymatrine at the concentration of 100~1000 mug/ml could significantly decrease the level of intracellular HCV RNA. No cytotoxicity was shown in such concentrations. CONCLUSIONS: Oxymatrine has an anti-HCV potential activity in vitro.

Alkaloids↗

PubMed2001

Molecular genetic profiling of Gleason grade 4/5 prostate cancers compared to benign prostatic hyperplasia.

PURPOSE: Because Gleason grade 4/5 cancer is the primary cause of failure to cure prostate cancer, we examined the molecular profiles of this high grade cancer in search of potentially new therapeutic interventions as well as better serum markers than prostate specific antigen. MATERIALS AND METHODS: We compared the gene expressions in fresh frozen tissues from 9 men with Gleason grade 4/5 cancer to 8 men with benign prostatic hyperplasia (BPH) treated with radical retropubic prostatectomy. Labeled complementary RNA from each of the 17 tissues was applied to HuGeneFL probe arrays representing approximately 6,800 genes (Affymetrix, Inc., Santa Clara, California). After removing all genes undetectable in BPH and grade 4/5 cancers, and transforming the data into a parametric distribution, we chose only those up and down-regulated genes with a p difference in fluorescence between grade 4/5 cancer and BPH of p <0.0005. This value reduced the data set to 40 up-regulated and 111 down-regulated genes. We then eliminated all genes that were not expressed in all 8 BPH and 9 grade 4/5 tissues, which produced a final set of 86 genes, of which 22 were up-regulated and 64 were down-regulated. RESULTS: Cluster analysis cleanly separated men with grade 4/5 cancers from those with BPH. Only 17 of the 86 candidate genes (20%) were known to be prostate cancer related and 42 (49%) were related to other cancers. The most up-regulated gene is Hepsin, a trypsin-like serine protease with its enzyme catalytic domain oriented extracellularly. Prostate specific membrane antigen is the second most up-regulated gene (all other reports on prostate specific membrane antigen have been at the protein level). The genes for prostate specific antigen (hK3) and human glandular kallikrein2 (hK2) showed equivalent expression levels 10 times the average of other genes. Complete lists of all 22 up-regulated genes and 64 down-regulated genes, together with their locus on the chromosome, are presented in rank order. CONCLUSIONS: We characterize for the first time 64 down-regulated and 22 up-regulated genes in Gleason grade 4/5 cancer, using the gene profile from BPH as control tissue. A number of interesting new genes, previously undescribed in prostate cancer, are presented as possibilities for further study.

Aged↗

PubMed2001

[Deletion mapping of chromosome 18q and Smad proteins expression analysis in urinary bladder carcinomas].

OBJECTIVE: To investigate the role of loss of heterozygosity (LOH) on chromosome 18q in the carcinogenesis and progression of urinary bladder cancer and to provide clues for early detection and positional cloning of related genes. METHODS: Deletion mapping was performed on 18q using 12 microsatellite markers. Immunohistochemistry staining was used to evaluate the expression level of two tumor suppressor candidates Smad 2 and Smad 4 in this region. RESULTS: LOH in at least one of the 12 microsatellites on 18q was detected in 84.2% (32/38) of patients with bladder cancer. The minimal deletion region included tumor suppressor candidate Smad 4. Immunohistochemical study revealed that 21.1% (8/38) of the cases had up-regulated Smad 2 protein and 34.2% (13/38) of the cases had down-regulated Smad 2 protein. Smad4 protein expression was down-regulated in 68.4% (26/38) of the cases but up-regulated Smad 4 expression was seen in only one case. CONCLUSIONS: LOH on 18q was closely linked with bladder cancer. The irregular expression of tumor suppressor candidates Smad 2 and Smad 4 may play important role in the initiation and progression of bladder neoplasms.

Adolescent↗

PubMed2001

[Comprehensive evaluation of medical system by using generalized fuzzy set theory].

Based on the theory of generalized fuzzy set, a comprehensive evaluation model has been built, which provides residuals estimate, evaluate function and test methods needed. Verified by the prognosis of 30 patients with myocardial infarction in a motion experiment during rehabilitation, its coincidence rate was found to be above 90%. This model can be developed and applied to medical system and other systems for evaluations as well.

Evaluation Studies as Topic↗

PubMed2001

[Subcloning and sequencing of DNA fragment related to salt tolerance in Sinorhizobium meliloti 042B].

A 4 kb ClaI DNA fragment related to salt tolerance from S. meliloti 042B was digested by HindIII down 2.4 kb fragment, and a 1.6 kb ClaII-HindIII fragment was retained on plasmid pML122. Then, the 2.4 kb DNA fragment was ligated with plasmid pBBR1-MCS2, and the recombinant plasmid was transformed to E. coli DH5 alpha, and transformant GS2 was obtained. Three-parental mating experiments were carried out with transformant GS2 as donor, salt sensitive strains GZ17 as recipient and pRK2013 as helper plasmid, then the transconjugant GG2 was selected on FY plates containing kanamycin and 0.4 mol/L NaCl. The remaining DNA fragment was self ligated with pML122 and then transformed into E. coli S17-1 and transformat GS0 was obtained. Two-parental mating experiment was carried out with transformant GS0 as donor and salt sensitive strain GZ17 as recipient, but no transconjugant was obtained on the FY plates. Then, the 2.4 kb HindIII DNA fragment was ligated into sequencing vector pGEM-7Zf(+) for sequencing. The result of sequencing and analysis showed that the 2.4 kb DNA fragment contained three ORFs. According to the result of sequencing, further subcloning was conducted and 1.9 kb HindIII-Sac II DNA fragment related to salt tolerance was obtained.

Amino Acid Sequence↗

PubMed2001

[Changes of tangent time constant in the transformation of F-V curve configuration in COPD and cor pulmonale patients and clinical implications].

OBJECTIVE: To explore the changes of tangent time constant (tau t) in the transformation of F-V curve configuration in COPD and cor pulmonale patients and clinical implications. METHODS: We determined the F-V curves in 90 COPD patients (43 with chronic bronchitis, 47 with emphysema) and 31 complicated with cor pulmonale; all patients were in the ameliorated period. The tau t at high, mid and low lung volumes, tau t75, tau t50, tau t25, were measured on each F-V curve. RESULTS: 1. Normal ranges: F-V curve configuration with plateau, linear, convex and concave types; |tau t75| > ls or < ls; tau t25 < ls; tau t relationship with "adolescent fashion" or "old fashion". 2. Light and moderate abnormality: With convex type; |tau t75| < ls; tau t25 approximately = ls or > ls; "trumpet fashion" changes. 3. Serious abnormality: With hyperbolic type; |tau t75| < ls; tau t25 = 4s-10s; "tower fashion" changes. CONCLUSION: Hyperbolic type, extreme prolongation of tau t25 and "tower fashion" changes can be assigned as 3 important indices to assess the severity of disease. The convenience and correctness of the method may be available for clinical application.

Adult↗

PubMed2001

[Study on the determination of iodine by inductively coupled plasma atomic emission spectrometry].

A new method for determining iodine had been developed in ICP-AES. An oxidant, NaNO2 and a sample containing iodine ion were mixed in the PHD hydroid generation device, the producing iodine molecules were nebulized in nebulizer and then the iodine gas came into troch directly. The problem that the intensity of iodine decreases with the increase of time was solved. It was found that NaNO2 decreased the effect of Cl- in the low acidity. A detection limit of 14 ng.mL-1 was obtained and the RSD of the measurement for 2 micrograms.mL-1 of iodine was 1.2% (n = 10). The average recoveries of iodine were 99.44%. The method was applied to the determination of salt and seawater.

Iodides↗

PubMed2001

[Simultaneous determination of hydride forming and non-hydride forming elements in human hair by hydride generation-inductively coupled plasma atomic emission spectrometry].

A method for simultaneous determination of both hydride forming and non-hydride forming elements in human hair has also been successful. The influence of HCl concentration, NaBH4 concentration, carrier gas flow rate and rinse time on hydride forming elements intensity, and the effect of between nebulization and hydride-nebulization system on non-hydride forming elements have been studied. The optimum experimental conditions are selected. This method has been applied to the analysis of standard human hair with satisfactory results.

Arsenic↗

PubMed2001

[Clinical value of preserving intercostal-brachial nerve during breast cancer operations].

OBJECTIVE: To study the value of preserving intercostal-brachial nerve during axillary dissection for breast neoplasms. METHODS: From June 1996 to December 1997, stage I, II breast cancer patients were divided into experimental group (n = 45) and control group (n = 60) respectively. The intercostal-brachial nerve was preserved in the experimental group and not in the control group. Both were followed up after operations. RESULTS: The postoperation morbidity of arm sensory disturbance was 7.1% in the experimental group, which was significantly different from that of the control group(63.3%, chi2 = 34.69, P < 0.01). No difference was noted in the recurrence rate between the two groups. CONCLUSIONS: Preserving intercostal-brachial nerve may significantly decrease the morbidity of postoperation arm sensory disturbance during axillary dissection for stage I, II breast cancer patients.

Adult↗

PubMed2000

Susceptibility of ATP-sensitive K+ channels to cell stress through mediation of phosphoinositides as examined by photoirradiation.

Cell stress is implicated in a number of pathological states of metabolism, such as ischaemia, reperfusion and apoptosis in heart, neurons and other tissues. While it is known that the ATP-sensitive K+ (KATP) channel plays a role during metabolic abnormality, little information is available about the direct response of this channel to cell stress. Using photoirradiation stimulation, we studied the effects of cell stress on both native and cloned KATP channels. Single KATP channel currents were recorded from cell-attached and inside-out patches of rat ventricular myocytes and COS-1 cells coexpressing SUR2 and Kir6.2. KATP channel activity increased within < 1 min upon irradiation. The activity resulted from increased maximal open probability and decreased ATP inhibition. The effects remained after the irradiation was stopped. Irradiation also affected the channels formed only by Kir6.2DeltaC35. The irradiation-induced activation was comparable to that induced by phosphoinositides. Analysis of phosphatidylinositol composition revealed an elevated phosphatidylinositol bisphosphate level with irradiation. Wortmannin, an inhibitor of phosphatidylinositol kinases, decreased both the irradiation-induced channel activity and the production of phosphatidylinositol bisphosphates. Radical scavengers also reduced the irradiation-induced activation, suggesting a role for free radicals, an immediate product of photoirradiation. We conclude that photoirradiation can modify the single-channel properties of KATP, which appears to be mediated by phosphoinositides. Our study suggests that cellular stress may be linked with KATP channels, and we offer a putative mechanism for such a linkage.

ATP-Binding Cassette Transporters↗

PubMed2000

The impact of birth weight on the racial disparity of end-stage renal disease.

PURPOSE: Blacks have a high rate of end-stage renal disease (ESRD) and low birthweight (LBW) than whites. LBW has been associated with ESRD. The purpose of this study was to assess impact of LBW on the racial difference in ESRD.METHODS: Patients born in SC after 1950 and diagnosed with ESRD between 1991-1996 were identified from the ESRD registry. Birth weight was compared for 858 black and 372 white patients and 2460 controls matched for age, sex, and race. LBW was defined as birthweight <2500 g.RESULTS: Among patients with ESRD, mean birthweight was lower in blacks than whites (3179 vs 3367 g, p < 0.001). LBW was more common in blacks than whites with ESRD (13.9 vs 7.5%, p = 0.02). The risk ratio for LBW among ESRD patients was 1.4 (95% C.I. 1.1 to 1.8) for blacks and 1.5 (95% C.I. 0.9 to 2.5) for whites. The population attributable risk (PAR) for ESRD due to LBW was greater for blacks than whites (33.6 vs 4.2 per 100,000).CONCLUSIONS: Birthweights were lower and LBW was more common among blacks than whites with ESRD. Moreover, LBW contributed more to the PAR of ESRD in blacks than whites. Thus, LBW may contribute to the greater risk for ESRD in African Americans than Caucasians. This preliminary study indicates that further research on the link between LBW and ESRD could be instructive in understanding the racial health disparities.

Journal Article↗

PubMed2000

The three-dimensional structure of a complex of a murine Fab (NC10. 14) with a potent sweetener (NC174): an illustration of structural diversity in antigen recognition by immunoglobulins.

The three-dimensional structure of a complex of an Fab from a murine IgG2b(lambda) antibody (NC10.14) with a high potency sweet tasting hap- ten, N-(p-cyanophenyl)-N'-(diphenylmethyl)-N"-(carboxymethyl)guan idine (NC174), has been determined to 2.6 A resolution by X-ray crystallography. This complex crystallized in the triclinic space group P1, with two molecules in the asymmetric unit. In contrast to a companion monoclonal antibody (NC6.8) with a kappa-type light chain and similar high affinity for the NC174 ligand, the NC10.14 antibody possessed a large and deep antigen combining site bounded primarily by the third complementarity-determining regions (CDR3s) of the light and heavy chains. CDR3 of the heavy chain dominated the site and its crown protruded into the external solvent as a type 1' beta-turn. NC174 was nested against HCDR3 and was held in place by two tryptophan side-chains (L91 and L96) from LCDR3. The diphenyl rings were accommodated on an upper tier of the binding pocket that is largely hydrophobic. At the floor of the site, a positively charged arginine side-chain (H95) stabilized the orientation of the electronegative cyano group of the hapten. The negative charge on the acetate group was partially neutralized by a hydrogen bond with the phenolic hydroxyl group of tyrosine H58. Comparisons of the modes of binding of NC174 to the NC6.8 and NC10.14 antibodies illustrate the enormous structural and mechanistic diversity manifest by immune responses.

Amino Acid Sequence↗

PubMed2000

Differential modulation of paclitaxel-mediated apoptosis by p21Waf1 and p27Kip1.

The impact of the cyclin dependent kinase (CDK) inhibitors p21Waf1 and p27Kip1 on paclitaxel-mediated cytotoxicity was investigated in RKO human colon adenocarcinoma cells with the ecdysone-inducible expression of p21Waf1 or p27Kip1. Ectopic expression of p27Kip1 arrested cells at G1 phase, whereas p21Waf1 expression arrested cells at G1 and G2. Expression of p21Waf1 after paclitaxel treatment produced much greater resistance to paclitaxel than did expression of p27Kip1. We attributed this difference to the additional block at G2 induced by p21Waf1, which prevented cells from entering M phase and becoming paclitaxel susceptible. Expression of p21Waf1 inhibited p34cdc2 activity and markedly reduced paclitaxel-mediated mitotic arrest, from 87.5 to 23%. In contrast, p27Kip1 expression also inhibited p34cdc2 but reduced mitotic arrest only slightly, from 87. 4 to 74.5%. We concluded that the G2 block produced by p21Waf1, but not by p27Kip1, contributed to their unequal modulation of sensitivity to paclitaxel-mediated apoptosis in RKO cells, and there is no causal relationship between paclitaxel-mediated cytotoxicity and elevation of p34cdc2 activity.

Antineoplastic Agents, Phytogenic↗

PubMed2000

Characterization of kinetics and thermostability of Acremonium strictum glucooligosaccharide oxidase.

The kinetic and thermostability properties of a glucooligosaccharide oxidase from Acremonium strictum were determined. This enzyme produces only maltobionic acid from maltose. It is most active at pH 9 to 10.5, and is most stable at pH 6.5. Values of both K(M) and V(max) on maltose are highest at pH 10. The highest values of K(M) and V(max) occur with glucose, maltopentaose, and maltoheptaose, whereas the lowest values of K(M) are with maltotriose and of V(max) are with maltohexaose. Values of K(M) with any substrate and at any pH are always substantially above 1 mM. Activation energies for catalysis and thermoinactivation are 23 kJ/mol and 421 kJ/mol, respectively. The N-terminal sequence is not homologous with any other oxidase, but has some homology with other proteins having different functions. These unusual properties suggest that glucooligosaccharides may not be the primary substrates of this enzyme.

Acremonium↗

PubMed2000

3-D AE visualization of bone-cement fatigue locations.

This study addresses the visualization of crack locations in bone-cement material using a three-dimensional acoustic emission source location technique. Computer software based on an earthquake location technique was developed to determine AE source locations and was used to investigate material cracks formed at the tip of a notch in bone cement. The computed locations show that the cracks form linear features with dimensions between 0.1 and 0.2 mm although larger linear features (almost 3.5 mm) also are present. There is a difference of about 2.5 mm between the average of the event locations, and the location of the tip of the notch is 2.5 mm, which may be due to the finite size of the sensors (5 mm in diameter).

Animals↗

PubMed2000

Inhibition of hippocampal kindling by metabotropic glutamate receptor antisense oligonucleotides.

Recent work has shown that metabotropic glutamate receptors (mGluRs) increase in response to seizure activity and can contribute significantly to the expression and progression of partial seizures. Using the kindling model of temporal lobe seizures, we evaluated the ability of local hippocampal injections of mGluR1 antisense or mGluR3 antisense oligonucleotides to suppress receptor expression and alter hippocampal kindling. Daily antisense injections in the hippocampus resulted in a significant decrease in mGluR1 or mGluR2/3 immunoreactivity. Rats injected with mGluR3 antisense showed a brief suppression of afterdischarge duration when compared to matched rats injected with a nonsense-oligonucleotide. Rats injected with a mGluR1 antisense oligonucleotide had a dramatic suppression of the rate of seizure progression with no significant effect on afterdischarge duration. Suppression of mGluR1 synthesis by local antisense inhibition may provide a new therapeutic approach for the control of epileptogenesis.

Animals↗

PubMed2000

An unusual human IgM antibody with a protruding HCDR3 and high avidity for its peptide ligands.

The crystal structure of the Fv molecule from a human monoclonal IgM cryoglobulin (Mez) was determined at 2.6 A resolution. Amino acid sequences of framework regions (FR) of the Mez light (L) and heavy (H) chain variable domains (VL and VH) are highly similar to their counterparts in another human Fv (Pot) previously subjected to X-ray analysis in our laboratory. As expected, the three-dimensional (3-D) structures of FR are quite similar in the two proteins, as are four of the six complementarity-determining regions (CDRs): CDRs 1 and 2 for both L and H chains. Absence of Pro 95L from the LCDR3 loop in Mez VL (relative to Pot LCDR3) results in compression of this loop and creates more space in the VL-VH interface. In the two IgMs, HCDR3 conformations differ significantly from all previously defined conformations for these loops. Pot has a 12-residue HCDR3 that collapses to fill all available space in the VL-VH domain interface, resulting in the formation of a relatively flat platform for antigen binding. In Mez, the HCDR3 is two residues longer and is comprehensively different. A semi-rigid ascending segment dominated by a Pro-Pro-Tyr sequence protrudes out into solvent. The descending portion has the sequence Gly-Trp-Gly-Gly-Gly, which promotes high local flexibility. This segment folds across the VL-VH domain interface to interact with residues in LCDR3. These features partition the Mez active site into two compartments, a large cavity between VL and VH and a smaller cavity lined entirely by constituents of the three heavy chain CDRs. Such an unusual topographical feature indicates why the Mez IgM does not bind to the Fc portion of intact human IgG antibodies in immunoassays yet interacts with high avidity with many Fc-derived octapeptides. The cavities are expected to be the repositories for the Fc-derived peptides, while the semi-rigid protrusion of the Mez HCDR3 prevents the close approach of another macromolecule (e.g. intact IgG) to the active site.

Amino Acid Sequence↗