Biomedical subjects
Publications and source records attributed to Y Shu.
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Hyperplastic glomerular epithelial lesion is an important determinant of the progression of idiopathic focal segmental glomerulosclerosis (FGS). The proliferation and differentiation of glomerular epithelial cells and parietal epithelial cells (PECs) are regulated differently by cyclin and cyclin-dependent kinase inhibitors (CKIs) during nephrogenesis. To access the cellular mechanism underlying epithelial hyperplasia in the development of FGS, the present study applied immunohistochemistry to 21 cases of FGS to demonstrate expression of cell-cycle molecules and phenotypic characterization in proliferative epithelial lesions in FGS. The materials included segmental sclerosis (18.1%), which was divided into monolayer epithelial lesions (64.6%) and cellular lesions (35.4%). All of the cellular lesions expressed cytokeratin, frequently with Ki-67 (82.4%) and less frequently with cyclin A (17.7%), but were invariably negative for podocyte markers (PHM-5 and synaptopodin) and CKIs (p27kip1 and p57kip2). Podocytes in nonsclerotic tuft in the same glomeruli with cellular lesions strongly expressed CKIs and podocyte markers. Moreover, electron microscopy showed that some large proliferating cells with prominent nucleoli have a broad cell base attached to Bowman's capsule. These cells have cilia and a junctional complex with neighboring hyperplastic cells, some of which directly cover the glomerular basement membrane. This suggests that cellular lesions are of PEC origin. Monolayer epithelial lesions also exclusively exhibited a PEC phenotype with reciprocal expression of podocyte markers and cytokeratin. In addition, CKIs are weakly expressed in monolayer epithelial lesions, suggesting a re-entry of cell-cycle quiescent. In conclusion, proliferation of PEC, sustained by repression of CKIs in nature and simultaneous activation of cyclin A, is the actual molecular background to the cellular lesions in FGS. Cellular lesions may result in monolayer epithelial lesions that retain the PEC phenotype and enter a common pathway to glomerulosclerosis.
AIMS: To investigate the distribution characteristics of CYP1A2 in a Chinese population, and to examine gender-related differences in CYP1A2 activity. METHODS: Two hundred and twenty-nine healthy subjects, 120 men and 109 women, were enrolled in this study. CYP1A2 activity was measured by plasma paraxanthine/caffeine (1,7X/1,3,7X) ratio 6 h after administration of 300 mg caffeine. The concentrations of paraxanthine and caffeine in plasma were detected by h.p.l.c. RESULTS: A 16-fold variation of CYP1A2 activity (range 0. 09 to 1.46) was shown in this study. The coefficient of variation (CV %) of CYP1A2 activity was 62.9%. Non-normal distribution of CYP1A2 activity was indicated by the Shapiro-Wilk test (P<0.001). Probit plots of CYP1A2 activity revealed a bimodal distribution with breakpoint of 1,7X/1,3,7X ratio of 0.12. The percentage of poor metabolizers (PMs) was 5.24% (95% CI: 2.35% approximately 8.13%) in this Chinese population. Residual analysis of the data also supported bimodality (P<0.01). The CYP1A2 activity of men was higher than that of women (median: 0.33 vs 0.23, P<0.001). A probit plot of CYP1A2 activity in men was shifted to the left compared with that in women. Based on phenotype, the gender-related difference was observed in extensive metabolizers (EMs) (P<0.001), but not in PMs (P >0.1). In addition, there was no sex-related difference in the incidence of PMs (P >0.1). CONCLUSIONS: There is a phenotypic polymorphism in CYP1A2 activity in this Chinese population, and CYP1A2 activity is higher in men than that in women.
A significant number of patients who relapse after allogeneic stem cell transplantation (SCT) for chronic myeloid leukaemia (CML) will achieve sustained molecular remissions after treatment with donor lymphocyte infusions (DLI) from the original stem cell donor. Leukaemia-free survival, defined as survival without evidence of relapse at any time after transplant does not account for patients who are successfully treated with DLI. To summarize adequately the response to treatment, a new summary probability, called the current leukaemia-free survival (CLFS), is proposed. This quantity is defined as the probability that a patient is alive and in remission at a given time after transplant. We discuss two statistical methods for estimating CLFS. The first is based on a multistate modelling approach. The second is based on an estimate constructed by looking at appropriate differences between Kaplan-Meier estimates. We compare these estimates using data on 189 consecutive patients who underwent SCT over a 7-year period.
It has been previously reported that omeprazole (OP) oxidation is mediated by CYP2C19 and CYP3A4 in human livers. In this study, we assessed their relative contributions with human liver microsomal fractions from Chinese populations that were genotyped by CYP2C19 and recruited from two ethnic groups, Han and Zhuang. The kinetics of 5-hydroxyomeprazole (5-OH-OP) formation was best described by the two-enzyme and single-enzyme Michaelis-Menten equations for liver microsomes from CYP2C19 extensive (EMs) and poor metabolizers, respectively. At a low substrate concentration that may be encountered in vivo, the monoclonal antibody to CYP2C8/9/19 strongly inhibited 5-OH-OP formation in EM microsomes, whereas troleandomycin (TAO) eliminated most of the formation at a high substrate concentration. In poor metabolizer microsomes, either TAO or anti-CYP3A4 could alone abolish 5-OH-OP formation. Furthermore, there were differences between homozygous and heterozygous EMs in the percentage of inhibition by TAO and the antibodies. At the low substrate concentration, OP 5-hydroxyaltion was correlated well with S-mephenytoin 4'-hydroxylation and CYP2C19 contents in liver microsomes of 34 Chinese individuals. Moreover, in these individuals, obviously genetic and somewhat ethnic differences in OP 5-hydroxylation were observed between different CYP2C19 genotypes (wt/wt > wt/m1 > m1/m1) and between Han and Zhuang (Han > Zhuang), respectively. The results indicate that CYP2C19 is a high-affinity enzyme for OP 5-hydroxylation by liver microsomes from Chinese individuals and that its contribution is CYP2C19 gene dependent and ethnically related. Similar studies indicate that OP sulfoxidation is mediated mainly by CYP3A4 and independent of CYP2C19 genotype status.
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AIM: To identify the cytochrome P450 isoforms involved in proguanil (PG) activation to cycloguanil (CG) in Chinese liver microsomes. METHODS: The kinetics of the CG formation from PG was determined in the liver microsomes of 6 Chinese subjects. Selective chemical inhibitors to various cytochrome P450 isoforms were employed to conduct inhibition experiments. The relationship between the CG formation and S-mephenytoin 4'-hydroxylation was analyzed. RESULTS: The kinetic behaviors of CG formation were described well by a single-enzyme Michaelis-Menten equation in five livers. The apparent Km and Vmax were (82 +/- 47) mumol.L-1 and (8 +/- 6) pmol.min-1.mg-1 protein, respectively. However, the remaining one displayed a two-enzyme kinetic behavior. Inhibition experiments showed that troleandomycin (100 mumol.L-1) and diethyldithiocarbamate (100 mumol.L-1), as potent CYP3A4 and CYP2E1 inhibitors, respectively, reduced the formation rate of CG by 81.1% and 47.23%, while quinidine (10 mumol.L-1), furafylline (20 mumol.L-1), and sulfaphenazole (10 mumol.L-1), which were inhibitors towards CYP2D6, 1A2 and 2C9/10, respectively, did not display significant inhibition. At a low PG concentration of 5 mumol.L-1, the CG formation correlated well with S-mephenytoin 4'-hydroxylation (r = 0.805, P < 0.05). Nevertheless, when a high substrate concentration (500 mumol.L-1) was used, the correlation coefficient decreased (r = 0.581, P < 0.05). CONCLUSION: The present study indicates that CYP3A4 and CYP2C19 are involved in PG activation to CG in adult Chinese liver microsomes. CYP2C19 played an important role in the clearance of PG at a substrate concentration close to in vivo therapeutic concentrations, while CYP3A4 gradually made a dominant contribution with the increase of PG concentration.
AIM: To develop an analytical method for simultaneous quantification of 5-hydroxyomeprazole (5-OH-OP) and omeprazole sulfone (OPS), and explore whether omeprazole (OP) is an appropriate phenotypic probe for CYP2C19 and CYP3A4 in Chinese liver microsomes. METHODS: OP metabolism in vitro was conducted in Chinese liver microsomes, and the major metabolites 5-OH-OP and OPS were determined using high pressure liquid chromatography (HPLC). Monoclonal antibodies anti-CYP2C8/9/19 and anti-CYP3A4 were employed to conduct inhibition experiments. The protein contents of CYP2C19 and CYP3A4 were quantified using Western blot analysis and densitometric scanning. RESULTS: 5-OH-OP and OPS gave a baseline resolution in the HPLC analysis. The detection limits for both compounds were 0.01 nmol and the recovery (98%-102%) had good precision with relative standard deviation of < 9.5%. Both anti-CYP2C8/9/19 and anti-CYP3A4 had a significant inhibitory effect (P < 0.05) on the 5-OH-OP formation in a substrate concentration-dependent manner, and anti-CYP3A4 alone could almost abolish the formation of OPS (> 87%). At a substrate concentration of 2 mumol/L OP, good correlations were found between OP 5-hydroxylation and S-mephenytoin 4'-hydroxylation activities (r = 0.72, P < 0.01), OP 5-hydroxylation activities and CYP2C19 contents (r = 0.82, P < 0.01), and OP sulfoxidation activities and CYP3A4 contents (r = 0.78, P < 0.01) in Chinese liver microsomes. CONCLUSION: OP metabolism is mediated mainly by CYP2C19 and CYP3A4, and OP can be used to probe CYP2C19 and CYP3A4 activities in Chinese liver microsomes at appropriate substrate concentrations with the HPLC method presently developed.
OBJECTIVE: Using fluorescence in situ hybridization to analyze chromosome mosaicism in human preimplantation embryos and access the influence of mosaicism on in vitro fertilization-embryo transfer (IVF-ET) and preimplantation genetic diagnosis. METHODS: Normal fertilized embryos, which were not suitable for embryo transfer and cryopreservation, and male embryos in preimplantation gender diagnosis were analyzed by fluorescence in situ hybridization. RESULTS: Two hundred and ninety three nucleuses were found among 38 embryos. The hybridization rate was 96.2%. Twelve embryos (31.6%) were normal. Twenty-eight embryos (73.7%) were diploid embryos, which included normal diploid embryos and embryos with diploid moscaicism. In addition, 19 (50.0%) embryos were considered to be chromosomal mosaics due to diploid mosaicism and abnormal mosaicsm. The frequency of mosaicism increased from 18.2% in < or = 4 cell-stage embryos to 68.4% and 50.0% in 5-8 cell-stage and > or = 9 cell-stage embryos respectively. CONCLUSION: The frequency of Mosaicism increases with successive cleavage divisions. Moscaicism may be one of the important factors affecting the success rates in IVF-ET. Identification of sex by analysis of a single cleavage cell is accurate; however, it would be better to biopsy 2 cells to reduce errors in preimplantation genetic diagnosis of single gene diseases.
This experiment was made to investigate the changes of lipoprotein lipase(LPL) and hepatic lipase (HL) activity and their effects on gallstone formation in rabbit model in which the stones were induced by high cholesterol diet. Activities of plasma LPL and HL were determined; other data including concentration of plasma lipoprotein cholesterol, concentration of bile cholesterol and bile acids were also obtained. The results showed that with the rabbits continuously fed on high cholesterol diet, LPL activity heightened markedly (P < 0.05), and HL activity increased gradually (3 and 4 weeks groups vs control group, P < 0.05). The changes of concentration of plasma VLDL-C and LDL-C were the same as that of LPL activity, but the concentration of plasma HDL-C, HDL2-C, HDL3-C and bile acids showed no significant changes (P > 0.05). These results suggest that the heightened activities of LPL and HL might make the liver take up more cholesterol, secrete it into the bile duct and hence accelerate gallstone formation.
The possibility that ectopic purinergic sensitivity develops following peripheral nerve injury was investigated in chronic constriction injury (CCI). Spontaneous firing of A-fibers originated from the injury site or from sensory endings of afferents in the contralateral sciatic nerve. ATP injected intravenously excited most of the injured fibers whereas none of the contralateral afferents responded to ATP. The ATP-induced effect was blocked by the P2 receptor antagonist reactive blue 2, but not the P1 receptor antagonist aminophylline. Neither the alpha-adrenoreceptor antagonist phentolamine nor the cyclooxygenase inhibitor indomethacin attenuated the ATP-evoked effect. We conclude that a novel ectopic purinergic sensitivity mediated by P2 receptors develops at sites of the CCI of nerves in the rat, which may contribute to neuropathic pain.
Recently, George et al. proposed a regression-based transmission/disequilibrium test for linkage using information on the parent-to-offspring transmission status of an allele at a marker locus. We extended this test by simultaneously testing for any population association by incorporating the presence/absence status of the associated allele as a covariate in the model. We used this method to analyze markers on chromosomes 1 through 21 of the Collaborative Study on the Genetics of Alcoholism data on alcoholism for possible association and linkage. We found nominal significance (at the 0.02 level) at eight different regions for linkage, though statistical significance may not be concluded due to multiple testing. The strongest evidence of linkage was observed for markers D4S2639 and D12S397 with p-values less than 0.005. We also found strong association between the trait and alleles 149 of D7S691 and 131 of D21S1437.
We analyzed the GAW11 data on alcoholism provided by the Collaborative Study on the Genetics of Alcoholism (COGA) using an extension of a new test of linkage and association for quantitative traits developed by George et al. [1999]. This method determines linkage between marker loci and quantitative traits, when allelic association is present between the trait and marker loci, by regressing the disease trait on the parental transmission of the allele of interest. We found no strong evidence of linkage to any markers. However, we found several markers suggestive of possible linkage that may deserve further investigation.
AIMS: The present study was designed to define the kinetic behaviour of sertraline N-demethylation in human liver microsomes and to identify the isoforms of cytochrome P450 involved in this metabolic pathway. METHODS: The kinetics of the formation of N-demethylsertraline were determined in human liver microsomes from six genotyped CYP2C19 extensive (EM) and three poor metabolisers (PM). Selective inhibitors of and specific monoclonal antibodies to various cytochrome P450 isoforms were also employed. RESULTS: The kinetics of N-demethylsertraline formation in all EM liver microsomes were fitted by a two-enzyme Michaelis-Menten equation, whereas the kinetics in all PM liver microsomes were best described by a single-enzyme Michaelis-Menten equation similar to the low-affinity component found in EM microsomes. Mean apparent Km values for the high-and low-affinity components were 1.9 and 88 microm and V max values were 33 and 554 pmol min-1 mg-1 protein, respectively, in the EM liver microsomes. Omeprazole (a CYP2C19 substrate) at high concentrations and sulphaphenazole (a selective inhibitor of CYP2C9) substantially inhibited N-demethylsertraline formation. Of five monoclonal antibodies to various cytochrome P450 forms tested, only anti-CYP2C8/9/19 had any inhibitory effect on this reaction. The inhibition of sertraline N-demethylation by anti-CYP2C8/9/19 was greater in EM livers than in PM livers at both low and high substrate concentrations. However, anti-CYP2C8/9/19 did not abolish the formation of N-demethylsertraline in the microsomes from any of the livers. CONCLUSIONS: The polymorphic enzyme CYP2C19 catalyses the high-affinity N-demethylation of sertraline, while CYP2C9 is one of the low-affinity components of this metabolic pathway.
Matrix metalloproteinases (MMPs) are involved in the remodeling and degradation of the extracellular matrix. Recently, it has been found that MMPs also contribute to processes not directly related to tissue remodeling, such as platelet aggregation or degranulation of airway gland cells. Since mucus secretion is closely related to ion channel function, we investigated whether MMPs could also be involved in the regulation of ion channels. We used human airway submucosal cell line Calu-3 to study the effects of MMPs on whole-cell current and transepithelial short-circuit current (I(sc)). Phenanthroline, a specific inhibitor of MMPs, increased whole-cell current with the half-maximally effective dose of 5.2 microM, and reversibly activated I(sc) in transepithelial measurements. Current stimulated by phenanthroline displayed linear current-voltage relationships and had inhibitor pharmacology and ion selectivity consistent with cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel activity. Zymography and Western blot showed significant expression of MMP-2 in Calu-3 cells. Moreover, anti-MMP-2 antibodies (1 microg/mL) increased whole-cell current and I(sc), whereas human recombinant MMP-2 (10 ng/mL) reduced it. We also studied the expression of MMPs and the effects of phenanthroline on whole-cell current in A549 cells, which are derived from airway surface epithelium and do not express CFTR Cl- channels. While these cells also showed significant expression of MMP-2, inhibition of this enzyme with phenanthroline exerted no significant effect on whole-cell current. It is concluded that MMP-2 is involved in the regulation of CFTR Cl- channels in human airways.
OBJECTIVE: To explore the therapeutic effect and its possible mechanism on using Chinese herbal medicine (CHM) for supplementing Kidney and Qi, and activating blood circulation in treating intrauterine growth retardation of fetus (IUGR). METHODS: Fifty-five cases of IUGR were observed, 30 of them were treated with CHM and 25 treated with amino acid for control. RESULTS: The neonatal birth weight in the CHM group was markedly greater than that in the control group. Not only the maternal fundal height and abdominal circumference, but also the fetal growth parameters, including biparietal diameter, head circumference, abdominal circumference, femur length in the CHM group increased much faster than those in the control group. After CHM treatment, the maternal serum levels of estriol (E3) and human placental lactogen (hPL) were close to the normal pregnancy group, but the levels in the control group were significantly different from the normal range. The umbilical venous plasma concentration of essential amino acids was markedly improved after treatment, however, the improvement in the CHM group was more significant than that in the control group. No adverse effect of CHM was found both in mother and fetus. CONCLUSION: CHM for supplementing Kidney and Qi, and activating blood circulation was more effective in the improvement of placental function and amino acid transportation than those of amino acid.
OBJECTIVE: To find a medicine to treat endometriosis effectively with less side-effect. METHODS: Dan'e mixture (DEM, consists of Radix Salviae Miltiorrhizae and Rhizoma Zedoariae) was used to treat 189 cases of endometriosis and the change of symptom and sign, the B ultrasonograph, the anti-endometrium antibody and endometriosis quantitative diagnostic index were observed, another 160 cases were treated with Danazol as control, also using animal model to treat with DEM and Danazol. RESULTS: One hundred and eighty-nine cases were treated for 9 months. According to National Standards, 39 cases (20.6%) were cured, 67 cases (35.4%) were markedly effective, 67 cases (35.4%) were effective, and 16 cases (8.4%) were ineffective. Compared with 160 cases treated with Danazol for 9 months, the total effective rates were 95% and 91.5% respectively, the difference between them was insignificant. Animal experiments showed the similar results to the clinical ones. CONCLUSION: SZM is a safe and effective medicine to treat endometriosis, which deserves further study and development. It is particularly helpful for diagnosis, treatment and prevention of endometriosis in the early stage.
OBJECTIVE: To study the feature of pancreatic microcirculatory impairment in caerulein-induced acute pancreatitis. METHODS: The AP model of subcutaneous injection of caerulein was studied by intravital fluorescence microscopy of erythrocytes labeled by FITC (FITC-RBC) and by scanning electron microscopy of vascular corrosion casts and light microscopy of Chinese ink-injected/cleared tissues. RESULTS: Animals treated with caerulein showed hyper-amylases. Contractions of intralobular arteriolar sphincter, presence of vacuoles in all the layers of sphincter, gross irregularity in capillary network of acini were observed in caerulein-induced groups. The decrease of pancreatic capillary blood flow (P < 0.01), reduction of functional capillary density, and irregular intermittent perfusion (P < 0.05) were found. CONCLUSIONS: Impairment and contraction of pancreatic intralobular arteriolar sphincter are the initial microcirculatory lesions in the early phase of acute pancreatitis induced by Caerulein, and play a key role in the pancreatic ischemia and pancreatic microvascular failure in acute pancreatitis.