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Biomedical subjects

H Jiang

Publications and source records attributed to H Jiang.

At least 217 records · Page 12Linked to original sources
PubMed2000

Combined optical and fluorescence imaging for breast cancer detection and diagnosis.

In this article, we present a novel approach that combines the best aspects of both endogenous optical imaging and exogenous fluorescent lifetime and yield imaging for breast cancer detection and diagnosis. Using this approach, spatial distributions of optical properties, fluorescence lifetime, and yield in tissue can be reconstructed from measured excitation and emission data at the surface of the breast tissue by regularized inverse algorithms. We show images from simulated data, as well as images from experimental data using tissue-like phantom materials in the laboratory.

Algorithms↗
PubMed2000

Identification of Sp1 as the transcription factor for the alternative promoter P2 of the bovine growth hormone receptor gene.

Growth hormone receptor (GHR) mRNA variants that differ in the 5'-untranslated regions (5'-UTR) have been isolated in various species. These 5'-UTR variants are generated from the use of alternative promoters and/or alternative splicing. The 5'-UTR 1B is one of the GHR 5'-UTR variants isolated in the bovine but its homologues are also present in other species. The 5'-UTR 1B is a predominant GHR 5'-UTR expressed in many tissues. In the present study, we screened a bovine genomic library and isolated a 1.7 kb bovine GHR genomic sequence including exon 1B and its 5' flanking region from which the GHR 5'-UTR 1B is generated. Using primer extension, two major transcription start sites were mapped in the bovine exon 1B. Transient transfection analysis of the 5' flanking region of exon 1B confirmed its promoter activity (termed P2) in both Hep G2 and BHK-21 cells. Furthermore, analysis of deletion promoter-reporter constructs found that the basal activity of P2 resided in the proximal region of P2. DNase I footprinting analysis and electromobility shift assay (EMSA) identified the ubiquitous transcription factor Sp1 as the binding protein to a GC box-containing DNA element within the proximal P2. Deletion of the GC box greatly reduced the activity of P2 in cell lines. The GC box-containing site also appeared to bind Sp1 in the nuclear extracts from diverse bovine tissues. This suggests that interactions of Sp1 with the GC box-containing element in the proximal region of P2 may be part of the mechanism for the expression of the bovine GHR 5'-UTR 1B in diverse tissues.

5' Untranslated Regions↗
PubMed2000

Diffusion of peroxynitrite into the human platelet inhibits cyclooxygenase via nitration of tyrosine residues.

Peroxynitrite (ONOO(-)), a reactive oxidant produced by the reaction between nitric oxide and superoxide, was found to diffuse into the platelet cytosol and inhibit arachidonic acid-induced platelet aggregations with IC(50) value of 5.8 +/- 1.2 microM. A fluorescence assay established that ONOO(-) diffused into the platelet cytosol in a manner that was inhibited (50-70%) by 4, 4'-diisothiocyanatostilbene-2,2'-disulfonic acid, an inhibitor of HCO(3)(-)/Cl(-) anion exchanger. Treatment of platelets with (-)-epigallocatechin gallate (2 microM), a tea polyphenol and inhibitor of tyrosine nitration, abolished the inhibitory effect of ONOO(-) on arachidonate-induced aggregations by 88%. ONOO(-) (50-300 microM), added to platelets 1 min before arachidonic acid, inhibited (20-100%) formation of platelet cyclooxygenase (COX) products thromboxane A(2) and 12-hydroxyheptadecatrienoic acid. Interestingly, simultaneous addition of ONOO(-) and arachidonic acid stimulated eicosanoid production by 20 to 60%. The inhibition of thromboxane A(2) generation correlated with the 5- to 10-fold increase in the 3-nitrotyrosine levels of the platelet COX. Experiments with purified COX-1 and COX-2 also showed 9-fold increase of 3-nitrotyrosine levels, which correlated with decreased (93-98%) production of prostaglandin H(2) when ONOO(-) (50 microM) was added 1 min before arachidonic acid. However, the addition of ONOO(-) (50-100 microM) simultaneously with arachidonic acid increased prostaglandin H(2) formation by 30 to 60%. Thus, the inhibitory effect of ONOO(-) involved nitration of COX tyrosine residues, whereas the stimulatory effect was likely to be a result of ONOO(-) functioning as a peroxide activator of eicosanoid signaling. Increasing doses of ONOO(-) not only inhibited platelet COX but also induced formation of unique eicosanoids: iso-prostaglandin F(2alpha), epoxyhydroxyeicosatrienoic acid, and trans-arachidonic acids, suggesting that OH and NO(2) radicals were generated from ONOO(-) in platelets. Formation of ONOO(-) from NO and superoxide may function as a platelet hormone-like COX regulatory mechanism in inflammatory processes in which large amounts of these molecules are produced.

Blood Platelets↗
PubMed2000

Expression of ERCC1 antisense RNA abrogates gemicitabine-mediated cytotoxic synergism with cisplatin in human colon tumor cells defective in mismatch repair but proficient in nucleotide excision repair.

Gemcitabine, or 2',2'-difluorodeoxycytidine (dFdC) is a new anticancer agent with significant activity against a broad spectrum of tumors either as a single agent or in combination with other active anticancer drugs. Studies in vitro and in vivo have demonstrated that dFdC produces cytotoxic synergism with cisplatin, or cis-diamminedi-choloroplatinum(II) (CDDP); however, the mechanism by which the synergism occurs has not been elucidated. We proposed that the nucleotide excision repair (NER) process, which is responsible for the cellular removal of CDDP-DNA adducts, may be a target for the mechanism of the cytotoxic synergism of dFdC and CDDP. Because the mismatch repair (MMR) pathway is involved in mediating CDDP cytotoxicity, making determination of the role of the NER in the cytotoxic synergism more complicated, and because tumors are often defective in MMR, we selected an NER-proficient, MMR-deficient, CP2.0 human colon carcinoma cell line as a model for this study. By an in vitro repair synthesis assay, we found that dFdC triphosphate (dFdCTP), the active metabolite of dFdC, inhibited the incorporation of [alpha-32P]dATP as well as the incorporation of [alpha-32P]dCTP, suggesting that the repair inhibition by dFdCTP does not result simply from competition for the incorporation site but rather is also due to prevention of chain elongation during the DNA resynthesis process. To determine whether the repair inhibition contributes to the cytotoxic synergism, we examined the effect of the constitutive expression of ERCC1 antisense RNA on the interaction of dFdC and CDDP. CP2.0 cells were transfected with pERCC1/AS, an ERCC1 antisense expression vector; eight hygromycine-resistant clones expressing various levels of the antisense RNA were selected for quantification of and correlation between the repair activity and cytotoxic synergism. The results show that stable expression of ERCC1 antisense RNA down-regulated the level of mRNA and repair activity; the down-regulation of the repair activity significantly correlated with the reduction of the cytotoxic synergism of the two agents. These data provide direct evidence to support the hypothesis that inhibition of the repair of CDDP-induced DNA lesions plays a critical role in dFdC-mediated cytotoxic synergism with CDDP in MMR-deficient tumor cells.

Antineoplastic Agents↗
PubMed2000

[Information behavior of microsatellite loci in genome scanning].

OBJECTIVE: To determine the heterozygosity and polymorphism information content of 139 microsatellite loci in Han population. METHODS: Multiplex approach was used to analyze the 139 loci. The amplified fragments were subjected to electrophoresis in PAGE gel and analyzed with Genescan( TM) and Genotyper(TM). RESULTS: The heterozygosities are between 0.35 to 0.89, with the heterozygosities of 88% loci >0.60. PICs are in the range of 0.32 and 0.88, with PICs of 95% loci >0.50. CONCLUSION: The polymorphism information content of microsatellite loci is very high and their distribution varies in different races and populations.

Aged↗
PubMed2000

[Preparation, characterization and drug release characteristics of poly(lactide)(PL)/poly(lactide-co-polyethylene glycol)(PLEG) blend microspheres].

PL and PLEG are biodegradable, biocompatible polymers. They have been widely used for controlled release of drugs. We synthesized PLEG copolymers containing PEG segments with various molecular weight and prepared hCG-loaded PL/PLEG blend microspheres to improve hCG entrapment efficiency. It was shown that the hCG entrapment effciency of PL/PLEG microspheres was higher than that of PL or PLEG microspheres when P(L-co-PEG6000)(90:10) was used. In vitro release test showed that the release of hCG was a burst-slow process, which was thought to be good for antigens to produce antibodies.

Chorionic Gonadotropin↗
PubMed2000

The effect of hypoxia on endogenous corneal epithelial eicosanoids.

PURPOSE: Injury to the corneal epithelium increases arachidonic acid (AA) metabolism through the cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 pathways. The authors used the rabbit corneal organ culture model to demonstrate the effect of hypoxia on the endogenous formation of 12-hydroxy-5,8,11,14-eicosatetraenoic acid (12-HETE), 12-hydroxy-5,8,14-eicosatrienoic acid (12-HETrE), and prostaglandin (PG) E2 by the intact cornea in the absence of exogenously added cofactors or substrate. METHODS: Rabbit corneas were isolated and cultured for 24 hours in normoxia or hypoxia. After culture, PGE2 in media was quantitated by enzyme immunoassay. 12-HETE and 12-HETrE were extracted from culture media and corneal epithelium and quantitated by negative chemical ionization-gas chromatography-mass spectrometry. COX-1 and -2 protein expression in corneal epithelium was determined by Western blot. Acute (2 hours) COX activity in normoxia and hypoxia was determined as the conversion rate of [14C]AA to [14C]PGE2, quantitated through reverse-phase-high-performance liquid chromatography and radiodetection. RESULTS: In the media of cultured rabbit corneas, both 12-HETE and 12-HETrE were detected, with 12-HETrE levels being four times higher. Hypoxia did not significantly increase extracellular 12-HETE or 12-HETrE; however, it caused more than 90% inhibition of PGE2 synthesis. Intracellular 12-HETE and 12-HETrE were undetectable in normal corneas but increased to 7.7+/-1.3 and 2.2+/-0.4 ng/mg protein, respectively, after 24 hours in culture. Culture in hypoxia further increased intracellular 12-HETE threefold but had no additional effect on 12-HETrE. CONCLUSIONS: Hypoxia creates an environment in which epithelial COX activity is severely suppressed, whereas cytochrome P450-AA and/or 12-LOX metabolizing activity is maintained or enhanced. Additionally, the findings suggest that 12-HETE produced by the corneal epithelium acts intracellularly to promote corneal edema, whereas 12-HETrE acts in a paracrine manner to initiate an inflammatory cascade that can elicit neutrophil chemotaxis and neovascularization of the cornea.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed2000

[Detection of fetal cells in maternal blood by fluorescence in situ hybridization].

OBJECTIVE: To isolate fetal nucleated cells from maternal blood and determine its fetal origin. METHODS: Enrichment and isolation of nucleated cells in maternal blood from 20 samples in the first trimester of pregnancy, 20 samples in the mid-trimester of pregnancy, and 15 samples after delivery. Fluorescence in situ hybridization was performed using Y specific probe PY3.4 to identify fetal cells. RESULTS: Fifteen women in the first trimester and 15 women in the mid-trimester of pregnancy carried male fetuses. The rates of positive cells were 1:6528.0 and 1:2783.8 respectively, and there was a highly significant difference when these rates were compared with the positive cells rate of the 10 female fetuses in the same trimesters. No significant difference in positive cells rate was found between 1 week after delivery and the mid-trimester of pregnancy, nor was it found between 3 months after delivery and the 10 samples of female fetuses in the same time. CONCLUSION: These data suggest that fetal cells can be detected as early as from 50 days of gestation in maternal blood, in the meantime, the rate of fetal cells will increase with gestational age. One week after delivery, fetal cells still exist, and 3 months after delivery, the fetal cells will no longer be detected.

Female↗
PubMed2000

Pain as a mutual experience for patients, nurses and families: a perspective from Shanghai, China.

The author of this article visited China for the purpose of helping the faculty of the School of Nursing learn research skills by participating in research--a kind of learn by doing. Both investigators had conducted quantitative studies in the US--one with children and one with adults--that were adapted for use in China. Seeking to also include a qualitative study, the investigators explored several possible research areas. Because pain is a universal phenomena, it was chosen as the subject for the study using the qualitative methodology reported in the first part of this article.

Adult↗
PubMed2000

Rat hepatocellular apoptosis induced by glycodeoxycholate.

OBJECTIVE: To explore the relationship between glycodeoxycholate (GDC) and rat hepatocellular apoptosis. METHODS: GDC was used to treat rat hepatocytes cultured in vitro and the apoptotic cells were observed and analyzed with light microscope, transmission electron microscope, TUNEL in situ hybridization, DNA agarose gel electrophoresis and flow cytometry. RESULTS: When rat hepatocytes were incubated with GDC (final concentration of 100 micromol/L) for 2h, apoptotic hepatocytes were observed with light and transmission electron microscope, and TUNEL in situ hybridization. When the hepatocytes were incubated with GDC (final concentration of 50, 100, 150 micromol/L, respectively) for 2h, or with GDC (final concentration of 100 micromol/L) for 2, 4, 6, 8h, respectively, agarose gel electrophoresis of the hepatocytes DNA demonstrated the typical ladder patterns. CONCLUSION: GDC with final concentration of 50, 100, 150 micromol/L could induce rat hepatocellular apoptosis.

Animals↗
PubMed2000

[Monitoring dopamine release by fast cyclic voltammetry: an in vivo study].

AIM AND METHODS: Using fast cyclic voltammetry (FCV) and carbon fibre microelectrode (CFMe), we monitored dopamine (DA) release from caudate putamen(CPu), nucleus accumbens(Acb) and central amygdaloid nucleus(CAN) of normal rats in vivo, in order to find out the suitable parameters to evoke DA release of certain area. DA release was evoked by electrical stimulation of medial forebrain bundle(MFB) or ventral tegmental area(VTA). RESULTS: DA release from CPu, Acb or CAN were different in contents and the characteristics of dynamics. CONCLUSION: Different parameters should be used according to the different sites of stimulation in order to get the maximal DA release during the experiment.

Animals↗
PubMed2000

[A study of sleep apnea monitoring method and instrument].

In this paper the fundamental principle and great significance of sleep apnea monitoring are introduced, and the status quo of this field at home and abroad is described. Several kinds of methods for sleep apnea monitorin are analyzed, and on this basis the authors have developed a cheap and portable sleep apnea monitoring instrument. Experiment results demonstrate that the instrument is of convenience, high accuracy and good performance.

Adult↗
PubMed2000

[A mechanistic model of phasic and phenological development of wheat. I. Assumption and description of the model].

The temperature effectiveness for wheat development was non-linearized and the apical and phenological development stages were systematically predicted by the scale of physiological development time which was based on the ecophysiological development process. The predicted apical development stages included single ridge stage, double ridge stage, floral initiation stage, stamen and pistil initiation stage, anther seperation stage, tetrad stage, and heading stage, while the predicted phenological development stages included germination stage, emergence stage, tillering stage, winterovering stage, green-turning stage, jointing stage, booting stage, heading stage, flowering stage, grain filling stage, and maturity stage. Four cultivar specific parameters were used to describe the genotypic differences of wheat development. They were temperature sensitivity, physiological vernalization time, photoperiod sensitivity, and intrinsic earliness, reflecting the genetic properties of different cultivars in thermal effectiveness, vernalization, photoperiod response and shortest time required for reaching flowering, respectively. The four parameters determined the physiological development time required for each development stage of different cultivars.

Models, Biological↗
PubMed2000

[Analysis on loss of heterozygosity of chromosome 17p13.3 in hepatocellular carcinoma and construction of genomic contig in the deleted region].

OBJECTIVE: To detect the status of loss of heterozygosity (LOH) on chromosome 17p13.3 in hepatocellular carcinoma (HCC) and determine a minimum region of LOH as well as construct genomic contig in LOH region. METHODS: Variable number tandem repeat (VNTR) and RFLP markers examined by Southern hybridization were used to detect LOH of HCC. Microsatellite markers amplified by PCR were detected for LOH by denatured PAGE. Using microsatellite primers, 3 rounds of PCR amplification were carried out to screen positive genomic clones. The contig was constructed by PCR detecting the reaction between microsatellite markers and individual genomic clone. RESULT: Fifty-four paired HCC samples were analysed with 16 polymorphic markers on chromosome 17p13.3. The data revealed that the region between D17S5 and D17S34 had a high rate of LOH (> 63%), but three markers (proximal to D17S5) toward centromere had low or no LOH. TP53 marker on chromosome 17p13.1 had a LOH rate of 31% which was lower than that on D17S5-D17S34 region. No LOH was found at D17S34, D17S1866 (proximal to telomere) and D17S5, D17S1574 (distal to telomere) in 2 cases of HCC. However, there was LOH between D17S849 and D17S1574 in some cases. In LOH region, genomic clones relative to 18 of markers were obtained. A contig covering 9 markers was constructed. CONCLUSION: Determination of the minimum LOH region on chromosome 17p13.3 in HCC and the construction of genomic clone contig provide basis for further identification of putative new tumor suppressor gene(s) in HCC.

Carcinoma, Hepatocellular↗
PubMed2000

[Clinical observation on therapeutic effect of xinyikang oral liquid in treating 92 patients of viral myocarditis].

OBJECTIVE: To observe the clinical effect of Xinyikang Oral Liquid (XYK) in treating viral myocarditis patients of Qi-Yin Deficiency and Evil-Toxin Encroaching Heart Type. METHODS: Randomized controlled method was adopted, the 92 cases in the XYK group received XYK and 30 cases in the control group received Qidong Yixin oral liquid treatment for 4 weeks as a therapeutic course. Their symptoms, signs, white blood cell count (WBC), erythrocyte sedimentation rate (ESR), lactate, aspartate aminotransferase (AST) dehydrogenase (LDH), creatine phosphokinase (CPK), creatine phosphokinase isoenzyme (CPK-MB), electrocardiogram (ECG) and dynamic ECG changes before and after treatment were observed. RESULTS: The improvement on chest stuffiness, short breath, fatigue and spontaneous perspiration in the treatment group was better than those in the control group (P < 0.05) and XYK showed obvious improving effect on ESR, AST, LDH, CPK and CPK-MB (P < 0.01 or 0.05). There was no adverse reaction or side-toxic effects revealed in using XYK. CONCLUSION: XYK has significant therapeutic effect in treating viral myocarditis.

Adolescent↗
PubMed2000

[Relationship between factor v Leiden mutation and Chinese Budd-Chiari syndrome and its clinical significance].

OBJECTIVE: To investigate the relationship between factor v Leiden (FvL) mutation and Chinese sporadic Budd-Chiari syndrome (BCS), familial BCS, and to explore the significance of FvL mutation in the etiology of BCS. METHODS: Twenty-five patients with sporadic BCS, 6 patients with familial BCS (from A and B families), 39 both A and B family members, and 31 healthy persons were detected for FvL mutation with PCR. Meantime, two family members were explored for the related etiology of BCS. RESULTS: Factor V Leiden mutation was detected in 4 of 6 patients with familial BCS and in 2 family members. AIII(7,11,15) and BII(10), AII(2) and BIII(5) were found FvL mutation, and mutation was heterzygous. FvL mutation in the two degrees was compatible with Mendel hereditery law. The frequency of FvL mutation in 31 BCS and 31 healthy persons showed no statistical significance: but the frequency of FvL mutation between the familial BCS and healthy persons showed statistical significance. Ten persons in A family had varicose vein of the low extremeties, which was compatible with autosomal dominant inheritance. CONCLUSION: FvL mutation is related to Chinese familial BCS, but is not related to Chinese sporadic BCS. FvL mutation may be a underlying pathogenicity of familial BCS. Varicose vein of the low extremeties may be one of the pathogenicity of familial BCS.

Adolescent↗
PubMed2000

[Transoral microsurgical treatment of craniocervical malformation].

OBJECTIVE: To discuss transoral microcervical treatment of 16 patients with craniocervical malformation. METHODS: Perioperative treatment including antibiotics, tracheotomy, intravenous nutrition was used in 16 patients. RESULTS: Eight patients had basilar impressions, 3 chronic atlantoaxial dislocation and 2 odontoid fracture, 2 lower clivus chordoma, and 1 granuloma in the ventral part of the medulla oblongata. Three patients received bone graft. Follow-up for 6 - 36 months showed that 14 patients resumed normal life but 1 died. CONCLUSIONS: Pre-craniocervical malformation can be treated by transoral approach microsurgically. Understanding microanatomy of this approach can reduce postoperative morbidity and complications. Perioperative treatment can prevent incision infection. Prevention of intraoperative CSF leakage must be emphasized.Bone graft can make craniocervical spine stable.

Adolescent↗