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Biomedical subjects

Y Cui

Publications and source records attributed to Y Cui.

At least 181 records · Page 10Linked to original sources
PubMed1999

[Experimental study on the effect of nourishing yin and tranquilizing of yangyin anshen koufuye].

Yangyin Anshen Koufuye could obviously decrease the spontaneous activity of rats, effectively shorten the process of falling into sleep of normal rats which were injected pentobarbital sodium and prolong the sleeping time. The effect of sedation and hypnotism were the same as Zhaoren Anshen Koufuye. Yangyin Anshen Koufuye also could markedly reduce the serum tensity of T3, T4 of hyperthyroid rats, which equaled to TCM's deficiency of yin. It also could prevent the glycogen content of liver from decreasing, decrease heart rate, resist weight losing, thus to show the effect of nourishing Yin and tranquilizing.

Animals↗
PubMed1999

[Analysis of the late curative effect of 432 cases with advanced squamous cell carcinoma of the maxillary sinus].

OBJECTIVE: To study the late curative effect of different methods used in the treatment of advanced squamous cell carcinoma of the maxillary sinus (SCMS). METHODS: A retrospective analysis of 432 cases with SCMS was done. Among them, 141 cases were in stage III, 291 in stage IV, 244 were male, 188 were female, and the age ranged from 14 to 87 years. Radiotherapy, operation only and the combined treatment (radiation plus operation) were adopted. RESULTS: The 5-year survival rates were 15.6% in radiation group, 21.7% in operation group, and 40.1% in combined group (40% in the preoperative irradiation group, and 43% in the postoperative irradiation group). The 5-year survival rates were 31.7%, 46.6% and 20% respectively for those involving structures above, below or both above and below the Ohngren line. Among the 238 cases with poor curative effect, 198 had local recurrence. CONCLUSION: Combined treatment was the best choice for advanced SCMS. There were no significant differences in the survival rates between preoperative and postoperative radiotherapy groups. The survival rate might be improved by preoperative radiotherapy with a dose of 50 Gy, or postoperative radiotherapy with doses of 60-70 Gy. The prognosis for those with the tumor located below the Ohngren line was much better than those above the line and those both above and below the line. The key to the successful treatment for maxillary sinus carcinoma is to control the local recurrence effectively.

Adolescent↗
PubMed1999

[Conservative surgery for glottic cancer with vocal cord fixation (T3)].

OBJECTIVE: To study the method of reconstruction of laryngeal function by unilateral bi-pedicled and bi-muscular flaps for glottic cancer of T3 category. METHODS: From 1984 to 1992, the unilateral bi-pedicled and bi-muscular flaps were used in 68 patients with T3 glottic cancer for repairing the surgical defect, enlarging the piriform recess on the affected side and closing the anterior wall of the laryngeal cavity after vertical laryngectomy. RESULTS: The 5-year survival rate was 73.5% (50/68). The decannulation rate was 91.2% (62/68). sixty-three patients had satisfactory phonation (92.6%). All patients resumed mouth-food-taking within 7 to 20 days after operation. CONCLUSION: The unilateral bi-pedicled and bi-muscular flaps are appropriate for reconstruction of surgical defect in T3 glottic cancer.

Adult↗
PubMed1999

The effect of keratinocyte growth factor-2 on esophagogastric anastomotic wound healing in rats.

BACKGROUND AND OBJECTIVES: Esophagogastric anastomotic leaks complicate 5-20% of esophagectomies for esophageal cancer, and they are responsible for approximately one-third of perioperative deaths. Growth factors enhance healing in several wound healing models. Keratinocyte growth factor-2 (KGF-2) is a newly identified growth factor that accelerates skin incisional healing. An animal experiment was done to test the hypothesis that KGF-2 would enhance esophagogastric anastomotic wound healing. METHODS: Forty rats had single layer esophagogastric anastomoses constructed using interrupted 7-0 polypropylene sutures. In the experimental group (20 rats) 1 mg of KGF-2 was administered by intraperitoneal injection on the day of surgery, and for three consecutive days thereafter. Placebo (buffer solution only) was given to the control rats (20 rats). Rats were sacrificed on the fourth postoperative day and their anastomoses were excised, mounted in a tensiometer, and distracted at 10 mm/min to measure breaking strength. After that, anastomotic tissue was subjected to hydroxyproline analysis (an indicator of wound collagen). Skin and fascial wounds were also tested in a tensiometer. RESULTS: There were two anastomotic leaks in the KGF-2 treated rats and none in the control rats (p = 0.26, not significant). Esophagogastric anastomotic breaking strength was 1.00 +/- 0.61 N in the KGF-2 treated rats and 1.58 +/- 0.62 N in the control rats (p = 0.017). Esophagogastric anastomotic tissue hydroxyproline concentration was 95.9 +/- 19.9 nmol/mg in the KGF-2 treated rats and 114.1 +/- 38.0 nmol/mg in the control rats (p = 0.10, not significant). Skin and fascia breaking strengths were also lower in the KGF-2 rats, but the difference was not significantly different (KGF-2 skin -0.97 +/- 0.48 N, Control skin -1.46 +/- 0.89 N, p = 0.064; KGF-2 fascia -3.60 +/- 2.06 N, Control fascia -4.67 +/- 1.88 N, p = 0.14). CONCLUSIONS: Keratinocyte growth factor-2 did not enhance esophagogastric anastomotic wound healing in this model. However, the dosage and route of administration of KGF-2 may have been sub-optimal for promotion of anastomotic healing. Further studies with this new growth factor are needed.

Anastomosis, Surgical↗
PubMed1999

Apoptosis of hemopoietic cells in irradiated mouse bone marrow.

Apoptosis of hemopoietic cells in bone marrow following radiation has been rarely reported, let alone studied quantitatively and pathologically. LACA mice were irradiated with 2.5, 4.0, 5.5, and 7.0 Gy gamma-rays, and the bone marrow was examined at 6 hours, 1 day, and 3 days after radiation. Semi-thin and thin sections were examined by light and electron microscopy. The number and area density of the apoptotic cells were assessed by means of a Cambridge Quantimet 970 Image Analyzer. We found that apoptosis occurred in only a few hemopoietic cells in the control mouse bone marrow, whereas 6 hours after radiation there were many apoptotic hemopoietic cells in each sample of irradiated bone marrow. Compared with controls, both the number and area density of the apoptotic cells markedly increased in the bone marrow of animals in every radiation dose group, and the difference was statistically significant (p < 0.01). Furthermore, the number and area density increased as the radiation dose increased. Our findings suggest that apoptosis is the main mode of radiation-induced hemopoietic cell death.

Animals↗
PubMed1999

[Fluorescence enhancement of the dysprosium-sulfosalicylic acid system by lanthanum and its application].

A fluorescence enhancement produced by adding lanthanum(III) to dysprosium-sulfosalicylic acid system was observed. La3+ enhanced the fluorescence intensity by two orders of magnitude compared with the system without La3+. The system was used for the determination of trace amount of dysprosium in the range of 3.0 x 10(-7)-1.0 x 10(-5) mol/dm3, and the detection limit was 8.0 x 10(-8) mol/dm3. The procedure was applied to the determination of dysprosium in synthetic rare earth samples and standard rare earth samples with satisfactory results.

English Abstract↗
PubMed1998

Chemokine receptor (CXCR4) mRNA-expressing leukocytes are increased in human renal allograft rejection.

BACKGROUND: Mononuclear cell infiltration is a common feature of cell-mediated renal transplant rejection. Chemokines and their corresponding receptors likely play a central role in directing specific classes of leukocytes to graft sites during rejection. Localization of chemokine receptors may help us understand how specificity in leukocyte trafficking is achieved in renal inflammatory processes. The localization of the chemokine receptor CXCR4 in human kidney and in renal transplant rejection is unknown. METHODS: We generated a riboprobe specific for the detection of CXCR4 mRNA by in situ hybridization to evaluate cellular sites of synthesis of this receptor in native human kidneys (n=11) and in human allograft nephrectomies with features of severe rejection (n=14). RESULTS: By in situ hybridization, CXCR4 mRNA expression is undetectable in intrinsic glomerular, tubular, and renovascular cells in native kidneys. When renal interstitial inflammation is present, CXCR4 mRNA expression is localized to a large fraction of infiltrating leukocytes. Large numbers of CXCR4-expressing cells are detected in cell-mediated renal allograft rejection. Double immunolabeling for CD3 antigen identified a large fraction of infiltrating CXCR4 mRNA-expressing cells as T lymphocytes. CXCR4 mRNA-expressing cells were frequently seen in neointimal lesions of vascular rejection in allograft nephrectomies. CXCR4 mRNA expression was identified in infiltrating neointimal T lymphocytes, but not smooth muscle cells by immunolabeling. CONCLUSIONS: We demonstrate the involvement of CXCR4 mRNA-expressing infiltrating cells in human renal interstitial and vascular allograft rejection. Signaling via the CXCR4 receptor may be one mechanism by which chemokines mediate leukocyte trafficking in renal allograft rejection.

Graft Rejection↗
PubMed1998

Exon-I is involved in positive as well as negative regulation of human angiotensinogen gene expression.

Angiotensinogen is the glycoprotein precursor of one of the most potent vasoactive hormones, angiotensin-II. Angiotensinogen gene is primarily expressed in the liver, and this gene locus is linked with human essential hypertension. We show here that a mutation in exon-I reduces the basal expression of the human angiotensinogen gene in liver cells. We also show that a nucleotide sequence in exon-I binds to liver-enriched transcription factor HNF-3 and a ubiquitous factor AP4. Our studies also show that transient transfection of an expression vector containing AP4 coding sequence downregulates the expression of reporter constructs containing human angiotensinogen gene promoter. By contrast, co-transfection of an expression vector containing HNF-3beta coding sequence increases the expression of these reporter constructs. The human angiotensinogen gene has a C/A polymorphism located at -20, and we have shown that estrogen receptor-alpha binds to this sequence when nucleoside A is present at this site. We show here that co-transfection of an expression vector containing AP4 coding sequence reduces estrogen-induced promoter activity of reporter constructs containing human angiotensinogen gene promoter (with nucleoside A at -20) attached to the CAT gene. These studies partly explain the molecular mechanisms involved in tissue-specific expression of the human angiotensinogen gene.

Angiotensinogen↗
PubMed1998

Simultaneous multispectral imaging in the visible and near-infrared region: applications in document authentication and determination of chemical inhomogeneity of copolymers.

A new multispectral imaging spectrometer capable of simultaneously recording spectral images in the visible and near-infrared has been developed. In this instrument, an acoustooptic tunable filter is used to diffract an unpolarized incident light into two diffracted beams with orthogonal polarization; one of them is detected by a silicon camera for the visible region while the other beam is detected in the near-infrared region (from 1 to 1.7 microns) with a NIR camera. The imaging spectrometer is sensitive, inexpensive, and field deployable because it is based on the recently available InGaAs focal plane arrays camera, which is low cost and can be sensitively operated at room temperature. Preliminary applications of the imaging spectrometer include measurements of the visible and NIR absorption spectra of ink used to print U.S. currency. Such results may help to characterize samples as well as to control and to ensure the quality of the samples during the production processes. More important are the results obtained on ethylene/vinyl acetate copolymers. The NIR spectral images obtained clearly indicate that these copolymers exhibit a high degree of chemical inhomogeneity. Because of the possibility of inhomogeneity, it is very important that the homogeneity of polymers or copolymers be thoroughly understood before the NIR methods, especially those based on NIR spectrometers equipped with a single-element detector, are used for measurements.

Diagnostic Imaging↗
PubMed1998

[Identification of a mutation hotspot in exon 8 of Wilson's disease gene by cycle sequencing].

OBJECTIVE: To screen for mutation hotspot of Wilson's disease (WD) gene in Chinese. METHODS: Cycle sequencing was used to detect mutation in exon 8 of WD gene in 30 patients with WD. RESULTS: The same missense mutation, Arg778Leu, was identified in 14 WD patients, four of which were homozygous and the others were heterozygous for this mutation. The frequency of this mutation was 30%. CONCLUSION: The codon 778(CGG-->CTG) of exon 8 in WD gene was one of mutation hotspots in Chinese.

Adolescent↗
PubMed1998

DBP binds to the proximal promoter and regulates liver-specific expression of the human angiotensinogen gene.

Angiotensinogen is the glycoprotein precursor of one of the most potent vasoactive hormones, angiotensin-II. It has been shown recently that an ATF like element (ALE) located between bases -102 and -87 of the human angiotensinogen gene plays an important role in liver specific expression of this gene and binds to CREB/ATF family of transcription factors and a novel factor (ALF). We show here that this sequence binds to the liver enriched transcription factor DBP and cotransfection of expression vector CMV-DBP increases the expression of reporter constructs containing this sequence. In addition, we show that transcription factor C/EBP-delta binds to this sequence and an expression vector containing C/EBP-delta coding region increases the expression of reporter constructs containing this sequence. Since DBP is involved in circadian rhythm, our studies suggest that this sequence may be involved in circadian expression of the human angiotensinogen gene.

Activating Transcription Factors↗
PubMed1998

BMP-4 is proteolytically activated by furin and/or PC6 during vertebrate embryonic development.

Bone morphogenetic protein-4 (BMP-4) is a multifunctional developmental regulator. BMP-4 is synthesized as an inactive precursor that is proteolytically activated by cleavage following the amino acid motif -Arg-Ser-Lys-Arg-. Very little is known about processing and secretion of BMPs. The proprotein convertases (PCs) are a family of seven structurally related serine endoproteases, at least one of which, furin, cleaves after the amino acid motif -Arg-X-Arg/Lys-Arg-. To examine potential roles of PCs during embryonic development we have misexpressed a potent protein inhibitor of furin, alpha1-antitrypsin Portland (alpha1-PDX) in early Xenopus embryos. Ectopic expression of alpha1-PDX phenocopies the effect of blocking endogenous BMP activity, leading to dorsalization of mesoderm and direct neural induction. alpha1-PDX-mediated neural induction can be reversed by co-expression of downstream components of the BMP-4 signaling pathway. Thus, alpha1-PDX can block BMP activity upstream of receptor binding, suggesting that it inhibits an endogenous BMP-4 convertase(s). Consistent with this hypothesis, alpha1-PDX prevents cleavage of BMP-4 in an oocyte translation assay. Using an in vitro digestion assay, we demonstrate that four members of the PC family have the ability to cleave BMP-4, but of these, only furin and PC6B are sensitive to alpha1-PDX. These studies provide the first in vivo evidence that furin and/or PC6 proteolytically activate BMP-4 during vertebrate embryogenesis.

Animals↗
PubMed1998

Cardiac Gsalpha overexpression enhances L-type calcium channels through an adenylyl cyclase independent pathway.

The alpha subunit of the stimulatory heterotrimeric G protein (Gsalpha) is critical for the beta-adrenergic receptor activation of the cAMP messenger system. The role of Gsalpha in regulating cardiac Ca2+ channel activity, however, remains controversial. Cultured neonatal cardiac myocytes from transgenic mice overexpressing cardiac Gsalpha were used to assess the role of Gsalpha on the whole-cell Ca2+ currents (ICa). Cardiac myocytes from transgenic mice had a 490% higher peak ICa compared with those of either wild-type controls or Gsalpha-nonexpressing littermates. The effect of Gsalpha overexpression was mimicked by intracellular dialysis of wild-type cardiac myocytes with GTPgammaS-activated Gsalpha. This effect was not mediated by protein kinase A activation as intracellular perfusion with a protein kinase A inhibitor rendered the same degree of activation in either transgenic or wild-type myocytes also dialyzed with activated Gsalpha. The data indicate that Gsalpha overexpression is associated with a constitutive enhancement of ICa which is independent of the cAMP pathway and activation of endogenous adenylyl cyclase.

Adenylyl Cyclases↗
PubMed1998

Protein folding simulation with genetic algorithm and supersecondary structure constraints.

We describe an algorithm to compute native structures of proteins from their primary sequences. The novel aspects of this method are: 1) The hydrophobic potential was set to be proportional to the nonpolar solvent accessible surface. To make computation feasible, we developed a new algorithm to compute the solvent accessible surface areas rapidly. 2) The supersecondary structures of each protein were predicted and used as restraints during the conformation searching processes. This algorithm was applied to five proteins. The overall fold of these proteins can be computed from their sequences, with deviations from crystal structures of 1.48-4.48 A for C(alpha) atoms.

Algorithms↗
PubMed1998

Processing of delta-endotoxin of Bacillus thuringiensis subsp. kurstaki HD-1 in Heliothis armigera midgut juice and the effects of protease inhibitors.

Bombyx mori was found to be more sensitive to the protoxins of HD-1 than Heliothis armigera. SDS-PAGE analysis showed that a large amount of activated toxin was yielded from protoxin by B. mori gut juice while little was yielded by H. armigera. Further degradation of activated toxin was observed in H. armigera midgut juice detected by SDS-PAGE. pH influenced the proteolytic activity of the midgut juice significantly, but there was no obvious effect of pH on the degradation of activated toxin. Specific inhibitor study revealed the presence of trypsin, chymotrypsin, and elastase in the midgut juice. TLCK, TPCK, elastatinal and some general serine protease inhibitors successfully prevented the excessive degradation of protoxin in H. armigera midgut juice. Chymotrypsin inhibitors showed strong inhibitory effects against the further degradation of activated toxin, indicating that chymotrypsin played a major role in the process. It was presumed that the excessive degradation of protoxin in H. armigera midgut juice was responsible for the low sensitivity of the insect to Bt. Further study demonstrated that the excessive degradation in vitro was triggered by SDS treatment. However, all of the tested serine protease inhibitors expressed synergism with protoxin against H. armigera larvae, suggesting that the excessive degradation of protoxin may occur in vivo to some extent and may be triggered by receptor binding of activated toxin.

Animals↗
PubMed1998

Cyclic ADP-ribose and the regulation of calcium-induced calcium release in eggs and cardiac myocytes.

Cyclic ADP-ribose (cADPR) is a cyclic metabolite of NAD+ synthesised in cells and tissues expressing ADP-ribosyl cyclases. Although it was first discovered in sea-urchin egg extracts as a potent calcium mobilizing agent, subsequent studies have indicated that it may have a widespread action in the activation of calcium-release channels in such diverse systems as mammalian neurones, myocytes, blood cells, eggs, and plant microsomes. In this review we focus on recent work suggesting that cADPR enhances the sensitivity of ryanodine-sensitive calcium-release channels (RyRs) to activation by calcium, a phenomenon termed calcium-induced calcium release (CICR). Two roles for cADPR in calcium signaling are discussed. The first is as a classical second messenger where its levels are controlled by extracellular stimuli, and the second mode of cellular regulation is that the levels of intracellular cADPR may set the sensitivity of RyRs to activation by an influx of calcium in excitable cells. These two possible actions of cADPR are illustrated by considering the signal transduction events during the fertilization of the sea-urchin egg and the modulation of CICR during excitation-coupling in isolated guinea-pig ventricular myocytes, respectively.

Adenosine Diphosphate Ribose↗
PubMed1998

Establishment of a novel cell line (TS-2) of pre-B acute lymphoblastic leukemia with a t(1;19) not involving the E2A gene.

The t(1;19)(q23;p13) translocation involving the E2A gene on chromosome 19p13.3 is a nonrandom translocation that is often seen in childhood pre-B-cell acute lymphoblastic leukemia (ALL). However, recent studies have demonstrated the presence of immunophenotypic and molecular heterogeneity among patients with the cytogenetically identical chromosome translocation. Here we report a novel pre-B ALL cell line, TS-2, with t(1;19) translocation not involving the E2A gene. The breakpoint of t(1;19) in TS-2 was demonstrated to be at 19p13.3, a region indistinguishable from the locus of the E2A gene, by cytogenetic study and fluorescence in situ hybridization. However, rearrangement of the E2A gene was not detected in TS-2 by Southern blot analysis. Moreover, the expressions of PBX1 or E2A/PBX1 fusion genes were not detected by an extensive study with Northern blot analysis and reverse transcription-polymerase chain reaction. These findings suggest that TS-2 may have a genetic abnormality involving uncharacterized gene(s) at 19p13.3 distinct from the E2A gene and, therefore, may be useful for investigating the heterogeneity of molecular pathogenesis in leukemias with t(1;19)(q23;p13) translocation.

Adenovirus E2 Proteins↗