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Biomedical subjects

Yang Xiao

Publications and source records attributed to Yang Xiao.

At least 19 recordsLinked to original sources
PubMed2006

Intermedin1-53 protects the heart against isoproterenol-induced ischemic injury in rats.

Intermedin is a novel member of the calcitonin/calcitonin gene-related peptide (CGRP) family peptide, which has vasodilatory and hypotensive actions identical to those of adrenomedullin and CGRP. Cleavage sites located between 2 basic amino acids at Arg93-Arg94 result in the production of prepro-intermedin95-147, namely intermedin1-53. The bioactive action of intermedin1-53 and its physiological significance are unclear. In this work, we aimed to explore the effects of intermedin1-53 on acute myocardial injury induced by isoproterenol. Myocardial ischemia injury in rats was induced by subcutaneous injection of a high dose of isoproterenol, and the therapeutic effect of intermedin1-53 was observed. Plasma lactate dehydrogenase activity, myocardial and plasma malondialdehyde content were higher in the isoproterenol group than that in controls. Isoproterenol-treated rats showed lower maximal rate of increase and decrease of left-ventricle pressure development (+/-left-ventricle dp/dtmax) and higher left-ventricle end-diastolic pressure (all P<0.01), which suggested severe heart failure and myocardial injury. Semi-quantitative RT-PCR analysis showed that the gene expression of calcitonin receptor-like receptor and receptor-activity-modifying protein (RAMP)1, RAMP2 and RAMP3 in ventricular myocardia were up-regulated by 79% (P<0.01), 48% (P<0.01), 31% (P<0.05) and 130% (P<0.01), respectively, compared with controls. In myocardial sarcolemmal membranes, the maximum binding capacity for [125I]-intermedin1-53 was increased by 118% (P<0.01) in the isoproterenol group compared with controls. Rats treated with low dosage intermedin1-53 (5 nmol/kg/day, 2 days) showed 21% (P<0.05) higher myocardial cAMP content, 18% and 31% higher+left-ventricle dp/dtmax and -left-ventricle dp/dtmax respectively, 288% lower left-ventricle end-diastolic pressure (all P<0.01), and attenuated myocardial lactate dehydrogenase leakage and malondialdehyde formation (all P<0.01). Treatment with high dosage intermedin1-53 (20 nmol/kg/day, 2 days) gave better results than that with low dosage intermedin1-53. These results suggest that the intermedin receptor system was up-regulated in isoproterenol-induced myocardial ischemic injury and intermedin1-53 might play a pivotal cardioprotective role in such injury.

Adrenomedullin↗
PubMed2006

Domain requirement for the membrane trafficking and targeting of syntaxin 1A.

Syntaxin plays a key role in intracellular membrane fusion in eukaryotic cells. The function of syntaxin relies on its proper trafficking to and targeting at the target membrane. The mechanisms underlying the trafficking and targeting of syntaxin to its physiological sites remain poorly understood. Here we have analyzed the trafficking of syntaxin 1A in INS-1 and CHO cells. We have identified the transmembrane domain together with several flanking positive-charged amino acids as the minimal domain required for the membrane delivery. Interestingly, we found that SNARE motif-exposed syntaxin 1A mutants were retained in endoplasmic reticulum (ER) and failed to transport to the cell surface in the absence of SNAP-25, suggesting that the exposure of the SNARE motif causes ER retention and complexation with SNAP-25 helps the ER escape. Finally, our data propose two key roles for the H(abc) domain: to protect nonspecific interaction by masking the SNARE motif and to participate in the clustering of syntaxin 1A to the fusion sites in the plasma membrane.

Animals↗
PubMed2006

Staining the anterior capsule with indocyanine green or trypan blue for capsulorhexis in eyes with white cataract.

AIM: To assess the efficacy and safety of indocyanine green (ICG) 0.5% and trypan blue 0.1% for anterior capsule staining in cases of white cataract. METHODS: This prospective study comprised 55 eyes of 55 patients with white cataract that had phacoemulsification with foldable intraocular lens implantation. ICG in 30 eyes and trypan blue in 25 eyes were used under air to stain the anterior lens capsule. The staining patterns and the ease of creating a continuous curvilinear capsulorhexis (CCC) were assessed; the intraoperative and postoperative complications were noted. The mean follow-up was 17.68+/-1.65 months. RESULT: Either ICG or trypan blue stained the anterior capsule uniformly. However, the staining provided by trypan blue was slightly superior. A CCC was successfully achieved in 25 eyes (100%) with trypan blue, and 29 eyes (96.7%) with ICG, respectively. There was no significant postoperative reaction in any eye. CONCLUSION: The use of vital dyes such as ICG and trypan blue guarantees a complete CCC and makes it possible to deliver the benefits of phacoemulsification in the patients with white cataract.

Aged↗
PubMed2006

Transpupillary argon laser photocoagulation and Nd:YAG laser cystotomy for peripheral iris pigment epithelium cyst.

PURPOSE: To report the use of a combination of transpupillary argon laser photocoagulation and Nd:YAG laser cystotomy in the treatment of peripheral iris pigment epithelium (IPE) cyst. DESIGN: Case report. METHODS: A 23-year-old man presented with a one-month history of blurred vision and pain in the right eye. Slit-lamp biomicroscopy and gonioscopy revealed, in the iridociliary sulcus, a large clear IPE cyst, which was demonstrated by ultrasound biomicroscopy (UBM). A combination of transpupillary photocoagulation to devitalize the epithelial lining and neodymium-doped yttrium aluminum garnet (Nd:YAG) laser cystotomy to drain the cyst was engaged. RESULTS: Laser treatment resulted in vanishing of the cyst and disappearance of the subject symptoms. Two months postoperatively, no evidence existed of the iris pigment cyst regrowth. CONCLUSIONS: The minimal invasiveness of the combination of transpupillary laser photocoagulation and cystotomy yielded a favorable result. This procedure may be an alternative to conservative regimen if IPE cyst is clearly defined and readily seen.

Adult↗
PubMed2006

Two-compartment sorption of phenanthrene on eight soils with various organic carbon contents.

Sorption characteristics of phenanthrene (PHE) were studied on eight soils with organic carbon contents spanning over an order of magnitude using phase distribution relationships (PDRs) at 1 h, 48 h, and 720 h contact times. A new algebraic method was employed to describe the sorption characteristics at different time intervals (between 1 h and 48 h, and 1 h and 720 h). It was found that nonlinearity increased with increasing contact time and sorption that occurred in the subsequent time interval following the initial 1 h exhibited stronger isotherm nonlinearity. Sorption coefficients were positively correlated with the organic carbon contents of the soils. Detailed sorption dynamics were also examined on these soils. A two-compartment, first-order model was used to describe the sorption dynamics. The rate constants of the two compartments differed 18-170 times, suggesting the dissimilar sorption behaviors of the mathematically separated compartments. These two compartments were labeled fast and slow sorption compartment according to the rate constants. Calculation showed that the fast compartment accounted for over 80% of the overall sorption at the initial 1 h, while the slow compartment predominated the total sorption in the following 47 h. By combining the discussion of PDRs and sorption dynamics, the contributions of the two compartments to linear and nonlinear sorption were differentiated. The slow sorption compartment made a major contribution to nonlinear sorption and possibly to sequestration of organic pollutants by these soils.

Adsorption↗
PubMed2006

[Distribution behaviors of phenanthrene to humic fractions in natural soil].

After adsorption of phenanthrene by the natural soil under different concentrations initially added, the soil sample was extracted for humic acid fraction (including humic acid and fulvic acid), and the sorption amount of phenanthrene in humin fraction was calculated to investigate the adsorption/distribution kinetics in two soil organic fractions and the corresponding influence of original phenanthrene concentration. The experimental data were fitted using Freundlich equation. The results show that, distribution of phenanthrene in the soil exhibited a multi-stage property, i.e., from a first fast sorption to a breakthrough at about 48 h, then followed by a slow sorption procedure. In the fast sorption stage (before 48 h), there was an up-to-down fluctuation of phenanthrene sorption ratio (sorption amount/added amount) in humic acid fraction, possibly due to surface sorption by minerals and competitive sorption by humin fraction. In the slow sorption stage, variations in sorption ratio in humic acid fraction was very small, and the influence of original concentration of phenanthrene was slight; while for humin fraction, the sorption ratio of phenanthrene at lower initial concentration was significantly higher than at higher one, in addition, the sorption ratio showed a gradually increasing trend, indicated humin fraction as the main domain in charge of the slow sorption. The fitting results of model parameters demonstrated that, sorption nonlinearity of phenanthrene in the natural soil increased in the following order: humic acid fraction< whole soil< humin fraction, and enhanced gradually. Different characteristics of humic acid and humin fractions in the multi-stage kinetics of phenanthrene sorption/distribution further reflected the effects of heterogenerity of soil organic fractions on nonlinear sorption behaviors.

Adsorption↗
PubMed2006

[Effects of electroacupuncture on GDNF positive cell immunoreactivity in local dermal tissue of the inflammatory pain focus in the rat of adjuvant arthritis].

OBJECTIVE: To study on the analgesic mechanism of electroacupuncture (EA) in the rat of adjuvant arthritis (AA). METHODS: Forty-eight SD rats were randomly divided into a blank control group (n = 8), an inflammatory group (n = 10), an acupoint EA group (n = 10), a non-acupoint EA group (n = 10) and a contralateral acupoint EA group (n = 10). Complete Freund's adjuvant (CFA) 50 microL were injected into the left malleolus' articular cavity in the rats except the blank control group for preparing single local adjuvant arthritis (AA) model. EA was given every other day to the acupoint EA group, the non-acupoint EA group and the contralateral acupoint EA group. The improving effects of EA at "Huantiao" (GB 30) and "Yanglingquan" (GB 34) on the dorsal flexion pain score and the swell of dorsum of hind paw were investigated, and effects of EA on Glial cell line-derived neurotrophic factor (GDNF) positive cells immunoreactivity in the inflammatory tissue of the AA rats on the 14th day after injection of adjuvant were observed with immunohistochemical technique. RESULTS: Hyperalgesia and local swell, and GDNF in the dermal and subcutaneous tissue around the inflammatory ankle joint in the inflammatory groups were significantly higher than those in the blank control group. EA on the ipsilateral and contralateral acupoints reduced the pain, promoted the recovery of swell, and decreased the positive area percentage and mean optical density of GDNF positive cells in the dermal and the subcutaneous tissues. However, the non-acupoint EA group did not have this action. CONCLUSION: EA can regulate expression of GDNF in local dermal tissue of the inflammatory focus in the AA rat, so as to exert the anti-inflammatory and analgesic effects.

Animals↗
PubMed2005

Characterization of a human rhomboid homolog, p100hRho/RHBDF1, which interacts with TGF-alpha family ligands.

The activity of the TGF-alpha-like ligand Spitz in Drosophila depends on Rhomboid, a seven-transmembrane spanning protein that resides in the Golgi and acts as a serine protease to cleave Spitz, thereby releasing the soluble ligand. Several rhomboids in Drosophila have been implicated in the processing of TGF-alpha-like ligands, and consequent EGF receptor activation. The larger number of TGF-alpha-like ligands in vertebrates raises the possibility that they too might be subject to regulation by rhomboid-like proteins. We present the cDNA cloning and polypeptide sequence of an atypically long human rhomboid, which, based on the absence of critical residues for serine protease activity, is not predicted to act as a serine protease. We examined its tissue distribution, in comparison with TGF-alpha and the TGF-alpha-related protein HB-EGF, and the EGF/TGF-alpha receptor, in mouse embryo. This rhomboid, named p100(hRho) or RHBDF1, is a seven-transmembrane protein with a long N-terminal cytoplasmic extension that comprises half of the polypeptide sequence, and is found in the endoplasmic reticulum and Golgi, but not on the cell surface. It is expressed as two forms with different lengths, forms dimers and interacts with TGF-alpha ligands through a luminal interaction with the EGF core ectodomain. Finally, we evaluated the function of p100(hRho)/RHBDF1 in Drosophila, demonstrating that the short, but not the full-length form has functional activity. The characterization of this protein extends our understanding of the rhomboid family of regulatory proteins.

Amino Acid Sequence↗
PubMed2004

Highly efficient luminescent organic clusters with quantum dot-like properties.

Organic clusters with uniform structure and size have been synthesized and studied. The quantum confinements on organic arms [chains shorter than exciton Bohr radii (aB)] have been confirmed by the discrete energy levels from PLE, narrow PL lines, size effect from UV, and spherical shape from TEM, as well as Raman peaks red-shifting and broadening. The results indicate the materials have QD-like properties.

Journal Article↗
PubMed2004

Capsular block syndrome caused by a reversed-optic intraocular lens.

A 52-year-old man who had phacoemulsification and in-the-bag fixation of a posterior chamber intraocular lens (IOL) developed capsular block syndrome 1 day after reverse implantation of the IOL. After a neodymium:YAG (Nd:YAG) laser peripheral anterior capsulotomy, the distended capsular bag collapsed significantly and the artificial myopia partially resolved. An Nd:YAG laser peripheral anterior capsulotomy appeared to be an effective, simple, and minimally invasive method to treat this problem.

Humans↗
PubMed2004

Prevention of cold-preservation injury of cultured endothelial cells by catecholamines and related compounds.

The present study was conducted to dissect the underlying mechanisms by which catecholamines protect cells against preservation injury. To this end, we firstly defined the cellular and molecular differences between protected and nonprotected cells and secondly defined the mediators that were involved in cold-induced damage. Cold storage of untreated human umbilical vein endothelial cells (HUVECs) resulted in profound cellular damage as assessed by lactate dehydrogenase (LDH) release and by morphological changes, e.g. cell size alterations and loss of cytoskeletal organization. Treatment of HUVECs with catecholamines before cold storage prevented cellular damage in a dose- and time-dependent fashion. Similar results were obtained with carvedilol or its hydroxylated derivative BM91.0228. Protection was not receptor-mediated and did not require de novo protein synthesis. The onset of protection occurred relatively quickly and the duration was long lasting. Addition of superoxide dismutase (SOD) to untreated HUVECs during cold preservation also was protective. Oxidation of catecholamines completely abrogated the protective effect of these compounds on cold-induced damage. Both at 4 degrees and 37 degrees C, catecholamines reduced the amount of reactive oxygen species (ROS) produced by HUVECs. In conclusion we have demonstrated that catecholamines protect cells against preservation injury either by scavenging of ROS or by inhibition of ROS production.

Blotting, Western↗
PubMed2004

Successful auricle replantation via microvascular anastomosis 10 h after complete avulsion.

OBJECTIVE: To report a case of successful total auricle replantation 10 h after complete amputation. MATERIAL AND METHODS: Replantation was achieved by means of microvascular anastomosis and other therapies, and assisted by careful nursing. The patient's auricle was completely cut off with a sharp blade by an assailant, who retained it for 5 h. Having been retrieved, it was then preserved in ice for 5 h. Using microscopy, an artery and vein were found at the confluences of the upper and middle and lower and middle parts of the amputated auricle and head wound, respectively An end-to-end anastomosis was performed on these vessels. After operation, the following treatments were used: drainage; reopening of the drainage channels with a needle: flushing or soaking with heparin sodium solution; controlling infection and coagulation; increasing blood volume: dilating vessels; and special nursing. RESULTS: The replanted auricle survived with a normal contour and a very favorable esthetic appearance. CONCLUSIONS: The neat, uncontaminated wound margins and the fact that the amputated auricle was preserved in ice, even though it had been amputated 10 h before the operation, were prerequisites for successful auricle replantation. The microvascular anastomosis technique played a very important role in the survival of the amputated auricle. The postoperative treatment, observation and nursing were difficult but vital aspects of the procedure. The establishment of an effective venous return was a sign of the survival of the amputated auricle.

Adult↗
PubMed2004

A human t-PA mutant cDNA cassette knocked in the murine fgfr-4 locus targeting for mammary gland expression.

The expression of foreign gene in transgenic animals produced by pronuclear microinjection is often confounded by the position effects caused by not only the nature of chromosomal integration site but also the number and arrangement of multiple transgene copies. Gene targeting provides a new way to overcome these inhibitions by introducing single-copy transgene into a chosen site. The choice of a good chromosomal site will favor transgene expression in a predictable fashion. In this study, we tested a new site (fgfr-4) for foreign gene integration and expression. A t-PA mutant (t-PAm) expression cassette under bovine alphas1-casein regulatory sequences was efficiently knocked-in fgfr-4 site through homologous recombination. The t-PAm was expressed in the milk of all targeted mice. Our experiment indicates that the fgfr-4 may be a candidate site for knocking foreign gene to make transgenic animals.

Animals↗
PubMed2004

[Research of spectrum characteristics for light conversion agricultural films].

The solar spectrum and the function spectrum in chrysanthemum and tomato were determined in this paper. The research for a relation plant growth to solar spectrum showed that the efficiency of plant making use of ultraviolet light of 280-380 nm and yellow-green light of 500-600 nm and near IR spectra over 720 nm are lower, that the blue-purple light of 430-480 nm and red light of 630-690 nm are beneficial to enhancing photosynthesis and promoting plant growth. According to plant photosynthesis and solar spectrum characteristic, the author developed CaS:Cu+, Cl- blue light film, and red light film added with CaS:Eu2+, Mn2+, Cl- to convert green light into red light, and discussed the spectrum characteristic of red-blue double peak in agricultural film and rare earth organic complex which could convert ultraviolet light into red light. Just now, the study on light conversion regents in farm films is going to face new breakthrough and the technology of anti-stocks displacement to study red film which can convert near infrared light are worth to attention.

Agriculture↗
PubMed2003

Induction of tumor angiogenesis by Slit-Robo signaling and inhibition of cancer growth by blocking Robo activity.

Slit is a secreted protein known to function through the Roundabout (Robo) receptor as a chemorepellent in axon guidance and neuronal migration, and as an inhibitor in leukocyte chemotaxis. Here we show Slit2 expression in a large number of solid tumors and Robo1 expression in vascular endothelial cells. Recombinant Slit2 protein attracted endothelial cells and promoted tube formation in a Robo1- and phosphatidylinositol kinase-dependent manner. Neutralization of Robo1 reduced the microvessel density and the tumor mass of human malignant melanoma A375 cells in vivo. These findings demonstrate the angiogenic function of Slit-Robo signaling, reveal a mechanism in mediating the crosstalk between cancer cells and endothelial cells, and indicate the effectiveness of blocking this signaling pathway in treating cancers.

Animals↗
PubMed2003

[Effect of antisense oligodeoxynucleotides of RNA component of human telomerase on cisplatin induced apoptosis in K562 cells].

OBJECTIVE: To research whether the antisense oligodeoxynucleotide (ASODN) of RNA component of human telomerase (hTR) can increase the susceptibility of K562 cells to cisplatin. METHODS: K562 cells were treated with phosphorothoate ASODN complementary to the template region of hTR in vivo. The changing of telomerase activity was assayed by TRAP-PCR-ELISA and apoptosis by DNA gel electrophoresis, Annexin V, flow cytometry. RESULTS: There was a marked decrease in telomerase activity in ASODN treated cells as compared with that in control and sense oligodeoxynucleotide (SODN)-treated cells; but no difference between the latter two groups. Agarose gel electrophoresis of genomic DNA from K562 cells treated with ASODN and cisplatin combination for 72 h showed typical DNA ladder; neither did DNA ladder from K562 cells treated with SODN plus cisplatin nor cisplatin alone. Apoptosis rates of K562 cells treated with ASODN for 24 h and then with cisplatin for 72 h were significantly increased. There were statistically significant difference in the percentage of apoptotic cells between hTR ASODN plus cisplatin and SODN plus cisplatin or cisplatin alone group. CONCLUSION: ASODN complementary to the template region of hTR can significantly suppress the telomerase activity and enhance cisplatin-induced apoptosis of K562 cells in vivo.

Apoptosis↗