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Biomedical subjects

J Huang

Publications and source records attributed to J Huang.

At least 55 records · Page 3Linked to original sources
PubMed2005

Quantification of the relative levels of wild-type and lamivudine-resistant mutant virus in serum of HBV-infected patients using microarray.

During the course of lamivudine administration in hepatitis B virus (HBV)-infected patients, a dynamic development of the viral population in serum is observed. Total HBV level is initially reduced, then lamivudine-resistant mutants appear, and finally, the viral level is increased. All methods of mutant detection so far described can only identify mutants in the serum, and cannot determine the proportion of those mutants. In this paper, we report the development of a novel technique that can quantify the relative proportion of mutants in serum utilizing gene microarray technology. Based on the nucleotide sequence at the loci of the mutations in lamivudine-resistant HBV mutants, 28 probes were designed and dotted on glass film to prepare the oligonucleotide microarray. Ten standard curves were established by employing 15 reference plasmids as templates. Ten standard math functions were simulated, which allowed quantification of the proportion of mutants in the sample by measuring the value of fluorescent intensity on the microarray. By utilizing the standard math function, the relative proportion of two different mutation sequences in the mixed template could be detected with an error <10%. The HBV-lamivudine oligonucleotide microarray is reliable to quantify the relative proportion of wild-type HBV vs HBV mutants in patient's sera.

Base Sequence↗
PubMed2005

Ovipositional site selection by Anopheles gambiae: influences of substrate moisture and texture.

The influence of substrate moisture (hydration) and grain size (texture) on oviposition was quantified in choice tests using Anopheles gambiae sensu stricto Giles (Diptera: Culicidae) laboratory strains and gravid An. gambiae sensu lato from a natural population in Western Kenya. A strong, positive correlation was found between moisture content and the degree of egg-laying, which peaked at saturation with standing water. Soil moisture quantified as surface conductivity, was measured with an electronic leaf-wetness sensor slightly modified from a unit available commercially. Although An. gambiae females were sensitive to measurable differences in substrate moisture, they distributed eggs on both fully hydrated and less hydrated substrates. In contrast, An. gambiae females showed little response to substrate texture: they oviposited with equal frequency on all silica substrates of eight particle size classes, ranging from small pebbles (850 microm diameter) to very fine grains (< 38 microm diameter), when all were moist. Female An. gambiae laid more eggs on dark than white substrates against a light background, but did not discriminate between moist, pulverized black soapstone and moist black Kenyan soil taken from typical An. gambiae larval habitats. We conclude that hydration and visual contrast are critical ovipositional site qualities for An. gambiae, but substrate texture is not.

Animals↗
PubMed2005

A novel blocking monoclonal antibody recognizing a distinct epitope of human CD40 molecule.

CD40, a member of the tumor necrosis factor receptor superfamily, is an important costimulatory molecule during the immune response. Here, we report a blocking mouse antihuman CD40 monoclonal antibody, mAb 3G3, of which the specificity was verified by flow cytometry and Western blot. It was shown by competition test that 3G3 bound to a different site (epitope) of CD40 from the reported CD40 mAbs, including clone mAb89, 3B2, and 5C11. It was also found that mAb 3G3 could inhibit homotypic aggregation of Daudi cells induced by the agonistic anti-CD40 mAb 5C11. Furthermore, mAb 3G3 effectively inhibited the proliferation of peripheral blood mononuclear cells in mixed lymphocyte reaction assay. Finally, a sensitive and specific soluble CD40 (sCD40) ELISA kit was established by matching mAb 3G3 with 5C11, and it was found that the levels of sCD40 in sera from patients with immune disorders such as hyperthyroidism, chronic nephritis, and rheumatoid arthritis were obviously higher than those from normal individuals. Thus, this blocking anti-CD40 mAb provides a novel tool for the study of CD40.

Antibodies, Monoclonal↗
PubMed2005

Oligonucleotide microarray for HLA-DRB1 genotyping: preparation and clinical evaluation.

In this study, HLA-DRB1 gene was genotyped by using the microarray technique. Oligonucleotide probes were designed based on partial sequences of various genotypes of HLA-DRB1, and were fixed on a silylated slide to form a microarray. The second exon of HLA-DRB1 gene in the extracted genomic DNA samples was amplified and labelled by means of polymerase chain reaction (PCR); then it was hybridized to the microarray. The microarray was scanned, and the result was analysed in order to determine the genotypes of HLA-DRB1 of the tested sample. A total of 1574 of 1592 clinical samples had accordant results of genotypes in either microarray assay or PCR-SSP assay; 8 of 10 samples that had inconsistent results of genotypes were proved to be microarray-assay reliable by confirmation of DNA sequencing. It is concluded that microarray is an alternative reliable method for HLA-DRB1 genotyping.

China↗
PubMed2005

Surgical treatment for upper or middle esophageal carcinoma occurring after gastrectomy: a study of 52 cases.

Fifty-two patients presenting with upper or middle esophageal carcinoma after gastrectomy between 1980 and 2003 were analyzed retrospectively. Among them, there were five cases of total gastrectomy, six cases of proximal partial gastrectomy and 41 cases of distal subtotal gastrectomy. The interval between gastrectomy and the diagnosis of esophageal carcinoma ranged from 2 to 22 years. Surgical procedures included resection of the esophageal lesion with esophageal replacement using non-reversed or reversed gastric tubes (2 and 3 cases respectively), and short or long segment colon (5 and 40 cases respectively); two cases underwent a palliative procedure (jejunostomy). Complications included cervical anastomotic leaks (3 cases), pulmonary infection (3 cases), atelectasis (2 cases) and cordis arrhythmia (5 cases), all of which responded to treatment. In our group, resection of the esophageal lesions and reconstruction of the esophagus was performed in 45 cases (86.5%), exclusion and bypass procedure of esophageal carcinoma and following radiotherapy and chemotherapy in four (7.7%), eternal jejunostomy for intestinal nutrition in two (3.9%) and death occurred in one case (1.9%) due to multiple organ dysfunction syndrome (MODS). Esophageal resection combined with lymph node dissection is indicated for the treatment of upper or middle esophageal carcinoma following gastrectomy. While esophageal substitutes can include non-reversed or reversed gastric tubes as well as short or long segment colon interpositions, we usually recommend the use of colon interposition. The 1-, 3- and 5-year survival rate of cases with resection of the esophageal lesions and reconstruction of the esophagus was 84.6%, 57.7% and 26.7% respectively.

Aged↗
PubMed2005

Association analysis of the variant in the regulatory subunit of phosphoinositide 3-kinase (p85alpha) with Type 2 diabetes mellitus and hypertension in the Chinese Han population.

AIMS: To determine whether variants in the gene for the regulatory subunit of phosphoinositide 3-kinase (p85alpha) are associated with Type 2 diabetes mellitus (Type 2 DM) and hypertension in a Chinese population. METHODS: We performed a case-control study genotyping the Met326Ile and IVS4+82A>G polymorphisms in 494 patients with Type 2 DM and hypertension and 557 normal controls from the north of China. Individual genotypes were identified by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The IVS4+82A>G polymorphism was further confirmed by direct sequencing in 20 randomly selected cases. RESULTS: The IVS4+82A>G polymorphism that is common in Caucasians was not detected in our population. Frequencies of genotypes and alleles of Met326Ile polymorphism were not significantly different between cases and controls in whole samples by univariate analysis. Logistic regression analysis demonstrated that Ile326Ile genotype was associated with a 2.085-fold (95% CI, 1.043-4.168, P = 0.0377) relative risk of diabetes and hypertension. After stratification by obesity, the frequency of Ile326Ile genotype in cases was higher than that in controls (18/304 vs. 13/510, P = 0.015) among non-obese individuals (BMI < 28 kg/m2). We did not find that this missense mutation was associated with blood pressure, glucose and blood lipids in the control group. CONCLUSION: Our data indicate that the Met326Ile variation in the gene encoding the p85alpha protein might contribute to the increased risk of Type 2 DM and hypertension in Chinese.

Aged↗
PubMed2005

Metalloproteinase expression by control and telomerase immortalized human endometrial endothelial cells.

Vascular endothelial cells play a critical role in the maintenance of endometrial homeostasis. Indeed many pathological conditions causing abnormal endometrial bleeding including progestin only contraception, hormone replacement therapy, endometrial polyps, myomas, hyperplasia and cancer are associated with aberrant angiogenesis. Critical to the process of angiogenesis is the breakdown of the surrounding tissues by matrix metalloproteases (MMPs). In addition to the cells surrounding the endometrial endothelial cells, the endothelial cells themselves produce their own panel of MMPs. We now characterize the specific MMPs that are expressed by endothelial cells derived from human endometrium. These include MMP-1, MMP-2 and MMP-10 but not MMP-3. In addition, in order to successfully carry out consistent, homogeneous and sufficient numbers of studies we investigated the in vitro expression of the MMPs with both freshly isolated, early passaged endometrial endothelial cells (HEECs) as well as with newly telomerase immortalized HEECs (T-HEECs). The latter were karyotypically normal and expressed classic endothelial cell endpoints such as tubulogenesis on matrigel and expression of the endothelial cell markers CD-31 (PECAM), von Willebrand's factor, and the Tie-2 receptors. The levels of MMP expression as well as that of the metalloprotease inhibitors TIMP-1 and TIMP-2 were similar in parent and immortalized endothelial cells.

Cell Line, Transformed↗
PubMed2004

Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun.

We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made.

Journal Article↗
PubMed2004

Eighteen living related liver transplants for Wilson's disease: a single-center.

The aim of this study was to review our experience with living related liver transplantation (LRLT) for Wilson's disease. From January 2001 to July 2003 LRLT were performed in 18 patients with Wilson's disease, seven of whom had neurologic complications. The mean age of the patients was 13.5 +/- 2.3 years (range 6 to 20). Before transplantation all recipients displayed low serum ceruloplasmin levels (mean value = 118.4 +/- 32.6 mg/L). The serum ceruloplasmin levels increased to an average of 236.8 +/- 38.5 mg/L after LRLT at the latest evaluation, which ranged between 2 and 32 months after transplantation. A marked reduction in urinary copper excretion was observed in all recipients after transplantation. All recipients are alive and remain well. None have developed signs of recurrent Wilson's disease after a mean follow-up of 18.2 +/- 9.4 months (range 2 to 32 months). The donors were 17 mothers and one father of mean age 34.0 +/- 3.0 years (range 30 to 45 years). The serum ceruloplasmin levels were within normal limits in all donors (mean 226 +/- 27.8 mg/L). Two donors had biliary leakage and percutaneous drainage Grafts included four right lobes without the hepatic middle vein and 14 left lobe grafts with the middle vein. LRLT is a curative procedure for Wilson's disease presenting with fulminant hepatic failure and the others with end-stage hepatic insufficiency. After liver transplantation, the serum ceruloplasmin level increases to the normal range, urinary copper excretion decreases, and neurological manifestations improve to various extents.

Adolescent↗
PubMed2004

In vitro assessment of the biological response to nano-sized hydroxyapatite.

Nano-sized, rod-like hydroxyapatite (nHA) crystals were produced and shown to be phasepure by X-ray diffraction analysis, as no secondary phases were observed. The nHA suspension was electrosprayed onto glass substrates using a novel processing routine to maintain nanocrystals of hydroxyapatite. The biocompatibility of nHAwas determined using human monocyte-derived macrophages and human osteoblast-like (HOB) cell models. The release of lactate dehydrogenase (LDH) from human monocyte-derived macrophages was measured as an indicator of cytotoxicity. The release of the inflammatory cytokine, tumour necrosis factor alpha (TNF-alpha) from cells in the presence of nHA crystallites was used as a measure of the inflammatory response. Although there was some evidence of LDH release from human monocyte-derived macrophages when in contact with high concentrations of nHA crystals, there was no significant release of TNF-alpha. Moreover, nHA-sprayed substrates were able to support the attachment and the growth of HOB cells. These results indicate that nHA crystals may be suitable for intraosseous implantation and offers the potential to formulate enhanced composites for biomedical applications.

Actin Cytoskeleton↗
PubMed2004

Hepatic fibrogenesis requires sympathetic neurotransmitters.

BACKGROUND AND AIMS: Hepatic stellate cells (HSC) are activated by liver injury to become proliferative fibrogenic myofibroblasts. This process may be regulated by the sympathetic nervous system (SNS) but the mechanisms involved are unclear. METHODS: We studied cultured HSC and intact mice with liver injury to test the hypothesis that HSC respond to and produce SNS neurotransmitters to promote fibrogenesis. RESULTS: HSC expressed adrenoceptors, catecholamine biosynthetic enzymes, released norepinephrine (NE), and were growth inhibited by alpha- and beta-adrenoceptor antagonists. HSC from dopamine beta-hydroxylase deficient (Dbh(-/-)) mice, which cannot make NE, grew poorly in culture and were rescued by NE. Inhibitor studies demonstrated that this effect was mediated via G protein coupled adrenoceptors, mitogen activated kinases, and phosphatidylinositol 3-kinase. Injury related fibrogenic responses were inhibited in Dbh(-/-) mice, as evidenced by reduced hepatic accumulation of alpha-smooth muscle actin(+ve) HSC and decreased induction of transforming growth factor beta1 (TGF-beta1) and collagen. Treatment with isoprenaline rescued HSC activation. HSC were also reduced in leptin deficient ob/ob mice which have reduced NE levels and are resistant to hepatic fibrosis. Treating ob/ob mice with NE induced HSC proliferation, upregulated hepatic TGF-beta1 and collagen, and increased liver fibrosis. CONCLUSIONS: HSC are hepatic neuroglia that produce and respond to SNS neurotransmitters to promote hepatic fibrosis.

Animals↗
PubMed2004

Molecular karyotyping using an SNP array for genomewide genotyping.

BACKGROUND: Chromosomal imbalances are a major cause of developmental defects as well as cancer and often constitute the key in identification of novel disease related genes. Classical cytogenetic methods are limited in resolution and dependent on highly skilled labour, while methods with higher resolution, based on molecular cytogenetics approaches such as matrix CGH, are not widely available. METHODS: We have developed and evaluated a method we term "molecular karyotyping", using readily available and easy to handle oligonucleotide arrays originally designed for parallel genomewide analysis of over 10,000 SNPs. We show that we can easily and reliably detect unbalanced chromosomal aberrations of various sizes from as little as 250 ng of DNA on a single microarray, based on fluorescence intensity information from clusters of SNPs. RESULTS: We determined the resolution of this method through analysis of 20 trios with 21 previously confirmed subtle aberrations sizing between 0.2 and 13 Mb. Duplications and deletions of at least 5 Mb in size were reliably detectable, but detection of smaller aberrations was dependent on the number of SNPs they contained, thus seven of 10 different deletions analysed, with sizes ranging from 0.2 to 3.7 Mb, were not detectable due to insufficient SNP densitiy in the respective region. CONCLUSIONS: Deduction of reliable cut off levels for array peaks in our series of well characterised patients allows the use of the GeneChip Mapping 10K SNP array for performing rapid molecular karyotyping from small amounts of DNA for the detection of even subtle deletions and duplications with high sensitivity and specificity.

Chromosome Aberrations↗
PubMed2003

Use of asymmetric somatic hybridization for transfer of the bacterial blight resistance trait from Oryza meyeriana L. to O. sativa L. ssp. japonica.

Bacterial blight is one of the major diseases affecting rice productivity. To improve the resistance of cultivated rice to bacterial blight, we introduced a bacterial blight resistance trait from Oryza meyeriana, a wild rice species, into an elite japonica rice cultivar (Dalixiang) using asymmetric somatic hybridization. One hundred and thirty-two independent lines were regenerated. The hybrid plants possessed several morphological features of the donor species, O. meyeriana. Random amplified polymorphic DNA analysis revealed that hybrid plants exhibited banding patterns derived from their parental genotypes. For the majority of the hybrids, resistance to bacterial blight pathogens was intermediate to that observed for O. meyeriana and O. sativa (cv. Dalixiang). Four of the hybrid lines exhibited a high bacterial blight resistance, but it was less than that observed for O. meyeriana. These results demonstrate that O. meyeriana can be used as a good genetic source for improving bacterial blight resistance in commercial rice cultivars through asymmetric somatic hybridization.

Crosses, Genetic↗