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Biomedical subjects

Zhiyong Huang

Publications and source records attributed to Zhiyong Huang.

11 recordsLinked to original sources
PubMed2026

Genetic and pathogenic characterization of a novel infectious bursal disease virus field strain with natural reassortant and recombinant features from southern China.

NN040124 is a novel field-derived IBDV strain (vv-A/att-B) exhibiting both reassortment and recombination events.Infection with NN040124 causes 40% mortality and severe lymphoid depletion in three-yellow chickens.These findings demonstrate the pivotal role of the N-terminal domain of segment B in IBDV pathogenicity and virulence.

A3B1a↗
PubMed2006

Differentiation and neurological benefit of the mesenchymal stem cells transplanted into the rat brain following intracerebral hemorrhage.

Spontaneous intracerebral hemorrhage (ICH) is often a fatal event. In a patient who survives the initial ictus, the resulting hematoma within brain parenchyma can trigger a series of events that lead to secondary insults and severe neurological deficits. Great efforts have been focused on searching for new approaches to help patients recover neurological function after ICH. Previous studies indicate that mesenchymal stem cells (MSCs) grafted into the ischemic rat brain can improve neurological function. However, there is no report regarding whether MSCs can be used in the same way to improve the neurological function after ICH. We generated the ICH model by injecting collagenase VII into rat brain. Subsequently, 5-bromo-2-deoxyuridine (BrdU)-labeled mesenchymal stem cells were delivered into the brain through carotid artery, cervical vein or lateral ventricle. The distribution and differentiation of MSCs were investigated by methods of immunohistochemistry. We found that MSCs were able to differentiate into neural cells in vitro as well as in the rat brain after ICH. The injected MSCs were able to migrate into hippocampus, blooding foci and ipsilateral cortex. In the hippocampus, MSCs differentiated into neurons; but in surrounding bleeding foci, they differentiated into neurons and astrocytes. In the ipsilateral cortex, MSCs differentiated into neurons, astrocytes and oligodendrocytes. Notably, the motor function of the rats in the carotid artery (CA) group and the lateral ventricle (LV) group improved significantly. Collectively, our study indicates that MSCs are able to differentiate into neural cells in the rat brain after ICH and can significantly improve motor function.

Animals↗
PubMed2006

Large-dose propofol during cardiopulmonary bypass decreases biochemical markers of myocardial injury in coronary surgery patients: a comparison with isoflurane.

We investigated if increasing propofol's dosage to augment its antioxidant capacity during cardiopulmonary bypass (CPB) could confer cardiac protection. Fifty-four coronary artery bypass graft surgery patients were randomly assigned to small-dose propofol (Group P; n = 18), large-dose propofol (Group HiP; n = 18), or isoflurane Group (Group I; n = 18). After the induction, anesthesia was maintained with an inspired concentration of isoflurane 1%-3.5% (Group I) or a continuous infusion of propofol 60 microg x kg(-1) x min(-1) (Group P) throughout the surgery. In Group HiP, this dose of propofol was increased to 120 microg x kg(-1) x min(-1) for 10 min before the onset of CPB until 15 min after aortic unclamping and then decreased to 60 microg x kg(-1) x min(-1) until the end of surgery. The duration of aortic cross-clamping was 83 +/- 24, 88 +/- 22, and 81 +/- 20 min in Group P, Group HiP, and Group I, respectively (P > 0.1). Plasma malondialdehyde, a marker of oxidative stress, was significantly lower at 8 h after CPB, and Troponin I was lower at 24 h after CPB in Group HiP compared with Group P and Group I (P < 0.05). There was a significant reduction in inotropic requirements for separation from CPB in Group HiP compared with Group I. Postoperative systemic vascular resistance was significantly reduced in Group HiP as compared with Group I. Mean cardiac index was significantly higher at 24 h after CPB in Group HiP compared with Group P and Group I (P < 0.05) (Group I, 2.2 +/- 0.1; Group P, 2.3 +/- 0.2; and Group HiP, 2.8 +/- 0.3 L x min(-1) x m(-2), respectively). The duration of intensive care unit stay was significantly shorter in Group Hi-P compared with Group I. We conclude that administration of a large dose of propofol during CPB attenuates postoperative myocardial cellular damage as compared with isoflurane or small-dose propofol anesthesia.

Aged↗
PubMed2005

A kernel autoassociator approach to pattern classification.

Autoassociators are a special type of neural networks which, by learning to reproduce a given set of patterns, grasp the underlying concept that is useful for pattern classification. In this paper, we present a novel nonlinear model referred to as kernel autoassociators based on kernel methods. While conventional non-linear autoassociation models emphasize searching for the non-linear representations of input patterns, a kernel autoassociator takes a kernel feature space as the nonlinear manifold, and places emphasis on the reconstruction of input patterns from the kernel feature space. Two methods are proposed to address the reconstruction problem, using linear and multivariate polynomial functions, respectively. We apply the proposed model to novelty detection with or without novelty examples and study it on the promoter detection and sonar target recognition problems. We also apply the model to mclass classification problems including wine recognition, glass recognition, handwritten digit recognition, and face recognition. The experimental results show that, compared with conventional autoassociators and other recognition systems, kernel autoassociators can provide better or comparable performance for concept learning and recognition in various domains.

Algorithms↗
PubMed2005

Lipid biomarkers and carbon isotope signatures of a microbial (Beggiatoa) mat associated with gas hydrates in the gulf of Mexico.

White and orange mats are ubiquitous on surface sediments associated with gas hydrates and cold seeps in the Gulf of Mexico. The goal of this study was to determine the predominant pathways for carbon cycling within an orange mat in Green Canyon (GC) block GC 234 in the Gulf of Mexico. Our approach incorporated laser-scanning confocal microscopy, lipid biomarkers, stable carbon isotopes, and 16S rRNA gene sequencing. Confocal microscopy showed the predominance of filamentous microorganisms (4 to 5 mum in diameter) in the mat sample, which are characteristic of Beggiatoa. The phospholipid fatty acids extracted from the mat sample were dominated by 16:1omega7c/t (67%), 18:1omega7c (17%), and 16:0 (8%), which are consistent with lipid profiles of known sulfur-oxidizing bacteria, including Beggiatoa. These results are supported by the 16S rRNA gene analysis of the mat material, which yielded sequences that are all related to the vacuolated sulfur-oxidizing bacteria, including Beggiatoa, Thioploca, and Thiomargarita. The delta13C value of total biomass was -28.6 per thousand; those of individual fatty acids were -29.4 to -33.7 per thousand. These values suggested heterotrophic growth of Beggiatoa on organic substrates that may have delta13C values characteristic of crude oil or on their by-products from microbial degradation. This study demonstrated that integrating lipid biomarkers, stable isotopes, and molecular DNA could enhance our understanding of the metabolic functions of Beggiatoa mats in sulfide-rich marine sediments associated with gas hydrates in the Gulf of Mexico and other locations.

Carbon Isotopes↗
PubMed2004

[Characterization method for metallothioneins by reversed-phase liquid chromatography coupled with electrospray ionization mass spectrometry].

Mammalian metallothioneins (MTs) usually have two major isoforms, MT-1 and MT-2, existing in tissues because of the genetic polymorphism. Metallothionein isoforms and sub-isoforms were characterized with a hyphenated technique of reversed-phase liquid chromatography (RPLC) coupled with electrospray ionization mass spectrometry (ESI-MS). The MT-isoform separation was carried out using a C8 narrow-bore column Vydac C8 (250 mm x 2.1 mm i.d., 5 microm, 30 nm). Buffer A was 5 mmol/L ammonium acetate in water (pH 6.0) and buffer B was 5 mmol/L ammonium acetate in methanol-water (1:1, v/v) (pH 6.0). A linear gradient elution was used by increasing buffer B from 10% to 37.5% within 40 min. The flow rate was set at 0.20 mL/min. The tentative formulas of MT isoforms and subisoforms were interpreted with the measured masses at the vicinity of apexes in total ion current chromatogram of ESI-MS and the reference data reported previously. The method was validated with the standard reference materials of MT-1 and MT-2. The results indicated that many MT species interpreted were in good agreement with the reference data reported. The MT sample from rabbit liver was measured with the established method. The results, of which the apo-MT was used by acidification of the sample for simplifying the mass spectra, showed that there were species of MT isoforms and subisoforms in rabbit livers.

Animals↗
PubMed2004

[Characterization of Hg-binding metallothioneins in tissues of rat after oral intake of mercury chloride by size-exclusion chromatography coupled with inductively coupled plasma-mass spectrometry].

Hg concentrations, total metallothioneins (MTs) and metal-binding MTs in tissues of the rat after oral intake of HgCl2 were determined by the inductively coupled plasma-mass spectrometry (ICP-MS), a modifield mecurry saturarion assay and the size-exclusion chormatography (SEC) coupled with ICP-MS, respectively. The results indicated that Hg accumulation in all of the rat tissues, including kidney, liver, testicle, brain, heart, serum and blood plasma, in HgCl2 group significantly increased compared with that in the control group, especiallyin kidney,liver and testicle. A large amount of MTs was inducted in these exposed rat tissues, especially in their kidneys and livers. The metal species binding with MTs obtained with SECICP-MS showed that the fractions of Hg-MTs in both kidney and liver of exposed rat were significantly higher compared with those of the control. In addition, higher amounts of Cu-MTs observed in exposed rat liver and kidney demomstrated the effect of MTs in the homeostatis of Cu and in the detoxification of Hg.

Animals↗
PubMed2003

Rhodocista pekingensis sp. nov., a cyst-forming phototrophic bacterium from a municipal wastewater treatment plant.

A novel bacterial species, Rhodocista pekingensis sp. nov., was isolated from a municipal wastewater treatment plant and characterized by polyphasic taxonomy. Cells of R. pekingensis were gram-negative, motile by a single polar flagellum, vibrioid to spiral, 0.6-0.8 microm in width and 0.8-1.5 microm in length. R-bodies were not observed. Phototrophically grown cells contained lamellar photosynthetic membranes and bacteriochlorophyll a. Cell growth was anaerobically phototrophic or aerobically chemoheterotrophic. Anaerobically grown cultures were pink-reddish. Thiamin and vitamin B12, but not biotin, were required for growth and 0.05% yeast extract stimulated growth. Acetate, lactate, pyruvate and succinate supported growth. Cysts were formed when butyrate was used as the sole carbon source. Molecular hydrogen (H2), but not sulfide or thiosulfate, was used as an electron donor. The major cellular quinone was Q-9. The DNA G + C content of cells was 68.8 mol%. The type strain of Rhodocista pekingensis is 3-pT (=AS 1.2194T=JCM 11689T).

Base Composition↗
PubMed2002

Rhodopseudomonas faecalis sp. nov., a phototrophic bacterium isolated from an anaerobic reactor that digests chicken faeces.

Five isolates of a previously undescribed species of purple non-sulfur phototrophic bacteria were characterized. They were Gram-negative, had mobile, budding vibrioid cells and contained lamellar intracytoplasmic membranes. Cultures produced red pigments in the light. Live cells of photosynthetic cultures exhibited absorption maxima at 382, 460-464, 494-496, 534-538, 596, 804-806 and 870-874 nm, indicating the presence of bacteriochlorophyll a and carotenoids belonging to the spirilloxanthin series in cells. The new isolates grew anaerobically or microaerobically in the light, but not aerobically in the dark. Optimal growth occurred at 35-40 degrees C and at pH 6.5-8.5. Various organic compounds were used as photosynthetic electron donors and carbon sources. Sulfate was used as sulfur source for growth. Ubiquinone 10 was synthesized as the major quinone. A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain gc(T), a representative of the new isolates, was closest to Rhodopseudomonas palustris, with a similarity of 97.5%. DNA-DNA hybridization further distinguished strain gc(T) from Rhodopseudomonas palustris at the species level. Therefore, the name Rhodopseudomonas faecalis sp. nov. was proposed for the new isolates. The type strain is gc(T) ( = AS1.2176(T) = JCM 11668(T)).

Animals↗
PubMed2002

[Selection of a composite microbial system MC1 with efficient and stability cellulose degradation bacteria and its function].

Four groups of microbial mix culture with considerable capability of cellulose degradation were selected from four compost heaps, by combining the four groups, a composite microbial system MC1 with highly efficient cellulose degradation was obtained. It was found that 0.48 g of filter paper, 0.49 g of absorbent cotton, 0.19 g of wheat straw, or 0.08 g of wood residue can be degraded by 100 mL of MC1 at 50 degrees C with in 72 hours under static culture. The CM1 saccharification activity was much higher at 24th hours when degrading filter paper that was 122.3 U.mL-1. This capability of degradation maintained more than 20 days when the substrates were continually added. MC1 could be inoculated in a wide pH rang, from 4 to 10; however, the final pH would be changed to neutrality after incubation. The pH would be stability with filter paper between 6.0 and 6.5, and between 8.0 and 8.5 without the filter paper.

Bacteria↗