Biomedical subjects

Q Xie

Publications and source records attributed to Q Xie.

At least 55 records · Page 3Linked to original sources

PubMed2000

Effect of tissue non-specific alkaline phosphatase in maintenance of structure of murine colon and stomach.

The gastrointestinal tract of mammals secretes a phospholipid-rich membrane that is enriched in alkaline phosphatase (AP) and surfactant proteins (surfactant-like particle, SLP). The production of this particle is stimulated in the small intestine by fat feeding and in cultured cells in vitro by transfection with intestinal alkaline phosphatase (IAP). To test whether tissue non-specific alkaline phosphatase (TNAP) was a factor in stimulating surfactant-like particle production in stomach and colon (tissues expressing TNAP), mice lacking this enzyme were studied. Mice were harvested at 8 days of life, when body weight of homozygous animals (TNAP -/-) was about half that of congenic controls (TNAP +/+) or heterozygotes (TNAP +/-), but before seizures had begun. No difference in content of the major SLP protein (65 kDa) by Western blotting or immunocytochemistry was seen in stomach or colon of TNAP -/- vs. TNAP +/+ animals, but the content was only about half in the IAP-expressing small bowel. Transmission electron microscopy of the TNAP -/- small bowel showed large dilated lysosomes and residual bodies. Colonocytes and gastric surface epithelial cells from the same animals showed mitochondria containing homogeneous dense inclusions, consistent with neutral lipid. In the underweight homozygous animals, there was a decrease in the neuronal content of submucosal ganglia in the jejunum and ileum and of myenteric ganglia in the jejunum of TNAP -/- animals. These findings suggest that (1) TNAP is not important in maintaining surfactant-like particle content of tissues that express TNAP, (2) normal fat absorption is important in maintaining SLP content in the small intestine, and (3) TNAP is important in the maintenance of some intestinal structures, and perhaps their function.

Alkaline Phosphatase↗

PubMed2000

Detection and analysis of Bacillus subtilis growth with piezoelectric quartz crystal impedance based on starch hydrolysis.

A piezoelectric quartz crystal (PQC) impedance method based on the alpha-amylase-catalyzed hydrolysis of starch present in a culture medium has been developed for in situ monitoring of the whole growth process of Bacillus subtilis and the variation in the activity of alpha-amylase during bacterial growth. An S-shaped response behavior was observed for Deltaf(0), and simultaneously inverse S-shaped responses were found for DeltaR(1) and DeltaL(1). The ratio of DeltaR(1) to Deltaf(0) or DeltaL(1) coincided well with that calculated from Martin's equations reflecting the solution density-viscosity effect, suggesting that the continuing change in liquid loading onto the PQC surface causes significant variation in Deltaf(0), DeltaR(1), and DeltaL(1). Bacterial growth equations were derived from the kinetics of the enzyme-catalyzed hydrolysis of starch, which fit well with the experimental responses of Deltaf(0), DeltaR(1), and DeltaL(1). Kinetic parameters of bacterial growth, including the asymptote (A), the maximum specific growth rate (microm), and the lag time (lambda), were obtained and were in good agreement with those obtained from the pour plate count method. The variation in the activity of alpha-amylase exhibited peak-type behavior with its maximum value at the later stage of the log phase. In addition, the influence of initial bacterial concentration was also investigated.

Algorithms↗

PubMed2000

Study of the Adsorption of Glutathione on a Gold Electrode by Using Electrochemical Quartz Crystal Impedance, Electrochemical Impedance Spectroscopy, and Cyclic Voltammetry.

Adsorption of a biological peptide, glutathione, on a gold electrode was studied by using electrochemical quartz crystal impedance (EQCI), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) techniques. The time courses of responses of piezoelectric and electrochemical impedance parameters were simultaneously obtained during the adsorption processes of the two forms of peptide, oxidized and reduced glutathione. It was found that the frequency curve due to the oxidized glutathione (GSSG) adsorption exhibited a character of a sum of two exponential functions. For reduced glutathione (GSH), the frequency adsorption curve could be expressed by a first-order reaction kinetic model and the corresponding kinetic parameters at different amounts of GSH were obtained. The heterogeneous charge-transfer rate constants of ferricyanide/ferrocyanide before and after the peptide adsorption were determined by CV and EIS methods, respectively. According to the simple equivalent electric network of the electrochemical interface, the electrochemical impedance parameters were also obtained. The results showed that the proposed method should be found in wider applications in interfacial biochemistry studies since these combined techniques have advantages in real time multidimensional information including electrochemical and electrochemical impedance parameters. Copyright 2000 Academic Press.

Journal Article↗

PubMed2000

The two isozymes of rat intestinal alkaline phosphatase are products of two distinct genes.

Rat intestinal alkaline phosphatases (IAP-I and -II) differ in primary structure, substrate specificity, tissue localization, and response to fat feeding. This study identifies two distinct genes ( approximately 5-6 kb) corresponding to each isozyme and containing 11 exons of nearly identical size. The exon-intron junctions are identical with those found in IAP genes from other species. The 1.7 and 1.2 bp of 5' flanking regions isolated from each gene, respectively, contain Sp1 and gut-enriched Kruppel-like factor (GKLF) binding sites, but otherwise show little identity. There is a potential CAAT-box 14 bp 5' to the transcriptional start site, 36 bp upstream from IAP-I, and a TATA-box 31 bp 5' to the transcriptional start site, 55 bp upstream from IAP-II. Transfection of these promoter regions (linked to luciferase as a reporter gene) into a kidney cell line, COS-7, produced the differential response to oleic acid expected from in vivo studies, i.e., threefold increase using the 5' flanking region of IAP-II, but not IAP-I. This response was not reproduced by 5,8,11,14-eicosatetraynoic acid (ETYA) or clofibrate, suggesting that peroxisome proliferator response elements are not involved. Isolation of the IAP-II gene will allow determination of the sequences responsible for dietary fat response in the enterocyte.

5' Untranslated Regions↗

PubMed2000

Prenatal X-irradiation increases GFAP- and calbindin D28k-immunoreactivity in the medial subdivision of the nucleus of solitary tract in the rat.

Glial fibrillary acidic protein- (GFAP) and calbindin D28k-immunoreactivity (IR) were investigated in the medial subdivision of the nucleus of the solitary tract (mNST) of prenatally X-irradiated rats. Pregnant rats were exposed to a single whole-body X-irradiation on day 11 or 16 of gestation at a dose of 1. 3 Gy. The offspring were killed at 7-14 days of age for the immunohistochemical observations. Rat pups showed strong GFAP-IR at the level rostral to the obex when receiving X-rays on day 11 of gestation, with hypertrophy of astrocyte cell bodies and cytoplasmic processes, but weak GFAP-IR when receiving X-rays on day 16 of gestation. Calbindin D28k-IR was stronger in the animals receiving X-rays on day 11 or 16 of gestation compared to that in the control animals. In the present study, the increase of GFAP- and calbindin D28k-IR cells in the mNST might indicate that adaptative mechanisms are taking place to preserve integrated nervous system function and possibly, to provide neuroprotection.

Adaptation, Physiological↗

PubMed2000

Expression and localization of Na(+)-HCO(3)(-) cotransporter in bovine corneal endothelium.

Functional studies support the presence of the Na(+)-HCO(3)(-) cotransporter (NBC) in corneal endothelium and possibly corneal epithelium; however, molecular identification and membrane localization have not been reported. To test whether NBC is expressed in bovine cornea, Western blotting was performed, which showed a single band at approximately 130 kDa for freshly isolated and cultured endothelial cells, but no band for epithelium. Two isoforms of NBC have recently been cloned in kidney (kNBC) and pancreas (pNBC). RT-PCR was run using cultured and fresh bovine corneal endothelial and fresh corneal epithelial total RNA and specific primers for kNBC and pNBC. RT-PCR analysis for pNBC was positive in endothelium and weak in epithelium. The RT-PCR product was subcloned and confirmed as pNBC by sequencing. No specific bands for kNBC were obtained from corneal cells. Indirect immunofluorescence and confocal microscopy indicated that NBC locates predominantly to the basolateral membrane in corneal endothelial cells. Furthermore, Na(+)-dependent HCO(3)(-) fluxes and HCO(3)(-)-dependent cotransport with Na(+) were elicited only from the basolateral side of corneal endothelial cells. Therefore, we conclude that pNBC is present in the basolateral membrane of both fresh and cultured bovine corneal endothelium and weakly expressed in the corneal epithelium.

Amino Acid Sequence↗

PubMed2000

Selective impairment of corticotropin-releasing factor1 (CRF1) receptor-mediated function using CRF coupled to saporin.

CRF is the main component in the brain neuropeptide effector system responsible for the behavioral, endocrine, and physiological activation that accompanies stress activation. Reduced CRF system activation plays a role in the etiology of a variety of psychiatric and metabolic disease states. We have developed a novel protein conjugate that joins native rat/human CRF to a ribosome-inactivating protein, saporin (CRF-SAP), for the purpose of targeted inactivation of CRF receptor-expressing cells. Cytotoxicity measurements revealed that CRF-SAP (1-100 nM) produced concentration-dependent and progressive cell death over time in CRF1 receptor-transfected L cells, but at similar concentrations had no effect on CRF2alpha receptor-transfected cells. The CRF-SAP-induced toxicity in CRF1-transfected cells was prevented by coincubation with the competitive CRF1/CRF2 receptor peptide antagonist, [D-Phe12]CRF-(12-41), or the selective nonpeptide CRF1 receptor antagonist, NBI 27914. Finally, in cultured rat pituitary cells that express native CRF1 receptors, CRF-SAP suppressed CRF-induced (1 nM) ACTH release. GnRH (1-10 nM) stimulated LH release was also assessed in the same pituitary cultures. Although there was a slight decrease in LH release from these cultures, this decrease was observed with CRF-SAP or SAP alone, suggesting that the response was nonspecific. Taken together, these results suggest the utility of CRF-SAP as a specific and subtype-selective tool for long term impairment of CRF1 receptor-expressing cells.

Adrenocorticotropic Hormone↗

PubMed2000

The effects of prenatal X-irradiation on hypoglossal nucleus: a GFAP immunohistochemical study.

The effects of prenatal X-irradiation on hypoglossal (XII) nucleus were investigated in the rat. Pregnant animals were exposed to a single whole body X-irradiation on day 11 and 16 of gestation at a does of 1.3 Gy. The offspring were killed at 7-14 days of age for the histological and immunohistochemical observations. Nissl staining revealed no significant changes of XII motoneurons in these experimental animals. In the control case it was of interest that expression of glial fibrillary acidic protein-immunoreactivity (GFAP-IR) is largely confined to the dorsomedial region including the XII nucleus at the level caudal to the obex. Exposure of X-irradiation on day 16 of gestation led to similar expression of GFAP-IR in the nucleus at the same level. However, exposure on day 11 of gestation apparently led to strong expression of GFAP-IR in the XII nucleus at the level caudal to the obex and the expression was observed to extend rostrally. The GFAP-IR cells showed hypertrophy of cell bodies and longer cytoplasmic processes. Horse-radish peroxidase (HRP) injection into the tip of the tongue including the intrinsic muscles resulted in retrograde labeling in the ventromedial portion of the XII nucleus bilaterally from +0.30 to -1.25 mm. The present study would indicate that motoneurons of the XII nucleus supplying mainly the intrinsic and partly the extrinsic tongue muscles are more sensitive to X-ray exposure before the formation of the XII nucleus.

Animals↗

PubMed2000

Induction of mouse CYP2J by pyrazole in the eye, kidney, liver, lung, olfactory mucosa, and small intestine, but not in the heart.

We have recently shown that rat CYP2J4 is inducible by pyrazole in liver, small intestine, and olfactory mucosa. The aim of the present study was to determine whether mouse CYP2Js are also inducible by pyrazole, which was known to induce CYP2A5 in mouse liver and kidney, but not in lung or olfactory mucosa. CYP2J proteins were detected in mouse liver, lung, kidney, heart, eye, olfactory mucosa, and small intestine by immunoblot analysis with an anti-CYP2J4 antibody. The microsomal level of the CYP2J4-related P450s in various mouse tissues ranked in the order of small intestine > olfactory mucosa > liver > kidney > or = heart > lung > eye. Induction of the CYP2J proteins was observed in the eye, liver, lung, kidney, olfactory mucosa, and small intestine, but not in the heart, after daily i.p. injection of pyrazole at 120 or 200 mg/kg for 3 days. CYP2J proteins were induced similarly in C57BL/6 and DBA/2 mice. CYP2A5 was detected in the small intestine in addition to liver and olfactory mucosa; however, treatment with pyrazole induced CYP2A5 in the liver, but not in the olfactory mucosa or the small intestine. Induction of CYP2J mRNAs was also observed by RNA blot analysis with a CYP2J4 cDNA probe. RNA-polymerase chain reaction analysis showed that, in both untreated and pyrazole-treated mice, CYP2J5 was expressed in the kidney and liver, but not in the other tissues examined, whereas CYP2J6 was detected in all tissues examined. The different tissue selectivities in CYP2A5 and CYP2J induction by pyrazole suggest involvement of different regulatory mechanisms.

Animals↗

PubMed2000

[Preparation and identification of hammerhead ribozyme in vitro against rat caspase-3 mRNA fragment].

OBJECTIVE: To study the transcript effect and cleavage activity in vitro of rat Caspase-3 specific ribozyme (Rz107 and Rz544). METHODS: Rat caspase-3 gene fragment was cloned into T-vector under the control of T7 promoter. (32)P-labeled caspase-3 transcript was target-RNA. Rz107 and Rz544 genes against caspase-3 mRNA were cloned and transcribed in vitro. Cleavage reaction was detected. RESULTS: It was found that Rz107 was active at 37 degrees C and more so at higher temperature within allowing temperature range. The optimal temperature was 50 degrees C. For Rz107, Km and kcat was 14.13 nmol/L and 2.31 min(-1), respectively. However, the Rz544 had no cleavage activity at all. CONCLUSION: Rz107 prepared in vitro possesses the perfect specific catalytic cleavage activity. It is hopeful that Rz107 would be developed to be a new nucleic acid drug that could effectively inhibit the inflammation of hepatitis through cleaving the key gene, caspase-3, in apoptosis in vivo.

Animals↗

PubMed2000

Hypotension after coronary arterial occlusion induces regional expression of c-Fos protein in the rat brain.

The purpose of this study was to examine comprehensively and quantitatively the effects of sustained occlusion of the circumflex branch of the left coronary artery on neuronal expression of Fos, the protein product of the proto-oncogene c-fos, in the rat brain. Occlusion coronary artery induced a fall in mean arterial pressure of about 10-30%, maintained for a period of 60 min. Baroreceptors were activated by occlusion coronary artery-induced hypotension. In control rats treated with without coronary ligation, few Fos-positive cells were observed. Following coronary artery occlusion, there was a significant increase in the number of Fos-positive cells in the several brain regions. These brain regions containing Fos-positive neurons in rats treated with coronary artery occlusion included nucleus tractus solitarius (NTS), area postrema (AP), caudal and rostral ventrolateral medulla (VLM), lateral parabrachial nucleus (PBN), supraoptic nucleus (SON), paraventricular nucleus (PVN) and central nucleus of the amygdala (CE). This finding partly differs from previous studies where Fos expression occurred by other reasons such as hypovolemia, hemorrhage, nitroprusside or hydralazine etc. These results generally fit within an emerging understanding of brain circuitry underlying cardiovascular regulation.

Animals↗

PubMed2000

[Different flow augmentations in coronary, carotid and renal arteries with ECP in experimental canines].

Different flow augmentations were found in canine's coronary, carotid and renal arteries with ECP because of their different anatomical locations in aorta. We used the Electromagnetic Blood Flowmeters to measure the blood flow pre-ECP and during ECP. The results showed ECP increased the diastolic flow of coronary, carotid and renal arteries by 24.48% +/- 1.29%, 27.18% +/- 0.94% and 20.68% +/- 0.80% respectively, decreased their systolic flow by 4.77% +/- 0.48%, 6.45% +/- 0.99% and 9.60% +/- 0.70%, but augmented their mean flow by 18.24% +/- 2.01%, 19.38% +/- 1.47% and 8.42% +/- 0.94% respectively in experimental dogs. These data demonstrate that ECP can greatly increase the mean flow of coronary and carotid arteries but at the same time patently decrease the systolic flow of renal artery.

Animals↗

PubMed2000

[Detection of microbes adherent to particles in a closed environment].

OBJECTIVE: In order to provide reference for controlling and monitoring the environmental contamination in the spacecraft, the species and amount of microbes, which adhere to the suspended particles with different size in a closed environment were detected. METHOD: According to USA EPA IP-10, particles were continuously sampled by an impactor in a closed environment. The particles were divided into three grades by their aerodynamic diameters (AD): 100 micrometers > or = AD > 10 micrometers, 10 micrometers > or = AD>2 micrometers and AD < or = 2 micrometers. Clean outdoor air was collected as control by the same way. The collected particles were precisely weighed. The microbes that adhere to the particles were cultivated, counted and identified. RESULT: By calculating total suspended particles (TSP) and inhalant particles (IP) of the closed environment, counting, clarifying and identifying the microbes, 6 kinds of bacteria, 2 genus of actinomyces and 6 kinds of fungi that adhere to the particles were detected. CONCLUSION: The particles in a closed environment may have some effect on human health and instruments.

Actinomyces↗

PubMed2000

[Endothelial dysfunction and injury of placental and umbilical vessels in pregnancy-induced hypertension is associated with tumor necrosis factor].

OBJECTIVE: To investigate the relation between endothelial dysfunction and injury of placental and umbilical vessels in pregnancy-induced hypertension (PIH) and tumor necrosis factor (TNF). METHODS: The concentration of plasma TNF, endothelin (ET) and nitric oxide (NO) in PIH women and normal pregnant women (control group) were measured. The ultrastructure of placenta and umbilical vein endothelial cells in PIH and normal pregnant women was observed. The ultrastructure of endothelial cells in culture with TNF (400 u/ml) was also observed. RESULTS: Maternal plasma TNF and ET levels in PIH patients were (2.27 +/- 0.42) micrograms/L and (73.31 +/- 9.98) ng/L, respectively, higher than that in the control [TNF and ET lever were (1.72 +/- 0.25) micrograms/L and (2.32 +/- 10.44) ng/L, respectively]. NO level in PIH patients was (104.93 +/- 20.54) mumol/L, lower than that in the control [NO lever was (138.25 +/- 22.16) mumol/L] (P < 0.05). The ultrastructure of placental and umbilical vascular endothelial cells in moderate and severe PIH patients revealed injured. Similar injury was observed in endothelial cells in culture with TNF. CONCLUSIONS: TNF can induce the endothelial cells dysfunction and injury. It may be involved the pathogenesis of PIH.

Adult↗

PubMed2000

Polymorphism of human platelet alloantigen in Chinese patients with acute myocardial infarction and acute ischemic stroke.

OBJECTIVE: To investigate the gene frequencies of 5 major human platelet alloantiqens (HPA 1-5) in Chinese population and to assess if polymorphism of HPA was associated with Chinese acute myocardial infarction (AMI) and acute ischemic stroke (AIS). METHODS: HPA 1-5 genotyping was performed by PCR using allele specific primers and restriction enzyme digestion based on PCR products in 95 AMI cases, 188 AIS cases and 270 normal controls. Gene frequency distribution was tested by Hardy-Weinberg equilibrium and comparison of HPA gene frequencies between the patient and control groups by chi 2 test. RESULTS: The gene frequencies of HPA 1-5 were the followings: HPA1a: 91%; 1b: 9%; HPA 2a: 94%; 2b: 6%; HPA 3a: 83%; 3b: 17%; HPA 4a: 98%; 4b: 2%; HPA5a: 97%; 5b: 3%. We found there were no significant differences in HPA 1-5 gene frequencies between AMI patients and normal controls. In AIS patients group HPA-2a allele frequency was significant higher than in controls, but this allele gene frequency in two groups (0.94 and 0.99) was very close and too many subjects in these two groups were overlapped. Otherwise no differences was found in other 4 HPA systems between cases and controls. CONCLUSION: Polymorphism of HPA were not inherited risky factors and not associated with chinese arterial thrombotic diseases such as AMI and AIS.

Adult↗

PubMed2000

[Role of tumor necrosis factor -alpha in the pathogenesis of pregnancy-induced hypertension].

OBJECTIVE: To investigate the role of tumor necrosis factor-alpha (TNFalpha) in the pathogenesis of pregnancy induced hypertension (PIH) by damaging endothelial cells. METHODS: 41 patients with PIH and 17 healthy pregnant women were studied. The concentration of TNFalpha in maternal plasma was measured by sensitive radioimmunoassay. The morphology of endothelial cells of placental blood vessels was observed. Endothelial cells were incubated in the presence of TNFalpha (400 U/ml) and sera (30% vol/vol) from PIH women and normal pregnant women to observe their growth and shape. RESULTS: Maternal plasma TNFalpha level in PIH was 2.29 microgram/L +/- 0.51 microgram/L, higher than that in normal pregnancy (the latter was 1.73 microgram/L +/- 0.25 microgram/L, t = 5.60, P < 0.01). The endothelial cells of placental blood vessels in PIH revealed morphologic damages. Both sera of PIH women and TNFalpha were cytotoxic to endothelial cells in culture, including inhibition of the proliferation and morphologic changes of the cells. CONCLUSION: Damage of the endothelial cells of placental blood vessels is associated with the abnormal increase in the maternal blood TNFalpha. Sera of PIH women can damage the endothelial cells in culture and this effect is also associated with TNFalpha.

Adult↗

PubMed2000

[Polymorphism of human platelets alloantigens in Chinese patients with acute myocardial infarction and acute ischemic stroke].

OBJECTIVE: To investigate the gene frequencies of 5 major human platelets alloantigens (HPA 1 - 5) in Chinese population and to assess if polymorphism of HPA is associated with acute myocardial infarction (AMI) and acute ischemic stroke (AIS) in the Chinese. METHODS: HPA 1 - 5 genotyping was performed with PCR using allele specific primers and restriction enzyme digestion based on PCR products in 95 AMI patients, 188 AIS patients and 270 normal controls. Gene frequency distribution was tested by Hardy-Weinberg equilibrium. Comparisons of HPA gene frequencies between the patient and control groups were made by chi(2) test. RESULTS: The gene frequencies of HPA 1 - 5 were listed as follows: HPA1a, 91%; HPA 1b, 9%; HPA 2a, 94%; HPA 2b, 6%; HPA 3a, 83%; HPA 3b, 17%; HPA 4a, 98%; HPA 4b, 2%; HPA 5a, 97%; HPA 5b, 3%. No significant differences were found in HPA 1 - 5 gene frequencies between AMI patients and normal controls. In AIS patient group, HPA-2a allele frequency was significantly higher than that in controls, but this allele gene frequency in the two groups was very close (0.99 and 0.94, respectively) and too many subjects in the two groups were overlapped. No differences were found in the other 4 HPA systems between patients and controls. CONCLUSION: Polymorphism of HPA is not an inherited risk factor and is not associated with Chinese arterial thrombotic diseases, such as AMI and AIS.

Acute Disease↗

PubMed2000

[The correlation between anticardiolipin antibodies and disease activity in patients with systemic lupus erythematosus].

This study was conducted to determine the prevalence and clinical association of anticardiolipin antibodies (ACA) in serum of patients with systemic lupus erythematosus (SLE). ACA (IgG, IgA, IgM) was measured by enzyme-linked immunosorbent assay (ELISA) in the serum sample of 87 patients of SLE. The prevalence rates of ACAIgG, ACAIgA and ACAIgM were 62.1%, 52.9% and 35.6% respectively. The titers of ACAIgG and ACAIgM were positively correlated with the disease activity (r = 0.2763, P = 0.044; r = 0.3294, P = 0.018); ACAIgG, ACAIgA and ACAIgM were negatively correlated with complement C3 (r = -0.4737, P = 0.000; r = -0.2990, P = 0.017; r = -0.2758, P = 0.029); and ACAIgG was negatively correlated with complement C4 (r = -0.4079, P = 0.005). The titers of ACAIgA in patients with thrombosis was higher than that in patients without thrombosis. The patients with central nervous system involvement (CNS-SLE) had significantly higher ACAIgG and ACAIgM titers, compared with those without CNS-SLE. The results indicate there is a correlation between ACA titers and disease activity. In patients with thrombosis, the titer of ACAIgA is higher, and in patients with CNS-SLE, the titers of ACAIgG and ACAIgM are higher.

Adolescent↗