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Y Deng

Publications and source records attributed to Y Deng.

At least 73 records · Page 4Linked to original sources
PubMed2000

PSM, a mediator of PDGF-BB-, IGF-I-, and insulin-stimulated mitogenesis.

PSM/SH2-B has been described as a cellular partner of the FcepsilonRI receptor, insulin receptor (IR), insulin-like growth factor-I (IGF-I) receptor (IGF-IR), and nerve growth factor receptor (TrkA). A function has been proposed in neuronal differentiation and development but its role in other signaling pathways is still unclear. To further elucidate the physiologic role of PSM we have identified additional mitogenic receptor tyrosine kinases as putative PSM partners including platelet-derived growth factor (PDGF) receptor (PDGFR) beta, hepatocyte growth factor receptor (Met), and fibroblast growth factor receptor. We have mapped Y740 as a site of PDGFR beta that is involved in the association with PSM. We have further investigated the putative role of PSM in mitogenesis with three independent experimental strategies and found that all consistently suggested a role as a positive, stimulatory signaling adapter in normal NIH3T3 and baby hamster kidney fibroblasts. (1) PSM expression from cDNA using an ecdysone-regulated transient expression system stimulated PDGF-BB-, IGF-I-, and insulin- but not EGF-induced DNA synthesis in an ecdysone dose-responsive fashion; (2) Microinjection of the (dominant negative) PSM SH2 domain interfered with PDGF-BB- and insulin-induced DNA synthesis; and (3) A peptide mimetic of the PSM Pro-rich putative SH3 domain-binding region interfered with PDGF-BB-, IGF-I-, and insulin- but not with EGF-induced DNA synthesis in NIH3T3 fibroblasts. This experiment was based on cell-permeable fusion peptides with the Drosophila antennapedia homeodomain which effectively traverse the plasma membrane of cultured cells. These experimental strategies independently suggest that PSM functions as a positive, stimulatory, mitogenic signaling mediator in PDGF-BB, IGF-I, and insulin but not in EGF action. This function appears to involve the PSM SH2 domain as well as the Pro-rich putative SH3 domain binding region. Our findings support the model that PSM participates as an adapter in various mitogenic signaling mechanisms by linking an activated (receptor) phospho-tyrosine to the SH3 domain of an unknown cellular partner.

3T3 Cells↗
PubMed2000

Characterization, chromosomal localization, and the complete 30-kb DNA sequence of the human Jagged2 (JAG2) gene.

The genomic sequence of the human Jagged2 (JAG2) gene, which encodes a ligand for the Notch receptors, was determined. The 30-kb DNA sequence spanning the JAG2 gene contains 26 exons and a putative promoter region. Several potential binding sites for transcription factors, including NF-kappab, E47, E12, E2F, Ets-1, MyoD, and OCT-1, were found in the human JAG2 promoter region. The JAG2 gene was also mapped to the chromosomal region 14q32 using fluorescence in situ hybridization.

Base Sequence↗
PubMed2000

Facile Synthesis of beta-Derivatized Porphyrins-Structural Characterization of a beta - beta-Bis-Porphyrin Financial support for this work was provided by the National Institutes of Health (GM 47274). The authors would like to thank William Cieslik from Hamamatsu Corporation for providing a C4334-0 Streak Camera for luminescence lifetime measurements and Alan Heyduk for assistance with the X-ray crystal structure determination.

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Journal Article↗
PubMed2000

Dot-immunobinding assay using indirect photoacoustic measurement.

Dot-immunobinding assay of hepatitis B surface antigen (HBsAg) was performed by a conventionally dot-ELISA technique with 4-chloro-1-naphthol staining, and the quantitative results were measured by an indirect photoacoustic method. In this method, a 2-mW helium-neon laser was applied to provide the excitation beam, the blue spots on the membrane were detected in a piezoelectric transducer-based photoacoustic cell. The operational conditions of measurement were optimized. A significant difference from the negative human serum was obtained for 50 pg in HBsAg detection. The method proposed provides a sensitive quantitative technique for dot-immunobinding assay.

Coloring Agents↗
PubMed2000

New antimicrobial flavanones from Physena madagascariensis.

Two new flavanones (1 and 2) with antibacterial activity were isolated from the methanolic extract of the dried leaves of Physena madagascariensis using activity against Staphylococcus aureus to guide the isolation. A third flavonoid, a flavanone dimer linked by a methylene group (3) was also isolated and proved to be inactive. The structures of 1 and 2 were established primarily from NMR studies, while that of 3 required more extensive mass spectrometric analysis. All three flavanones had lavandulyl units in the limonene form. Flavanones 1 and 2 were active against several bacteria at concentrations as low as 4 microM.

Anti-Bacterial Agents↗
PubMed2000

An unusual foreign body in the tongue.

A T-shaped metal object from an umbrella embedded in the tongue of a 4-year-old male child is described, along with its subsequent removal. The types of foreign bodies reported in this area are also mentioned.

Child, Preschool↗
PubMed2000

Potential cytotoxic effect of chronic administration of creatine, a nutrition supplement to augment athletic performance.

Creatine is alleged to be an ergogenic aid to enhance sports performance and recently became a popular sports nutrition supplement. Although short-term supplementation of creatine has not been associated with major health risks, the safety of prolonged use has caused some concern. The present study demonstrates that creatine is metabolized to methylamine, which is further converted to formaldehyde by semicarbazide-sensitive amine oxidase (SSAO). Formaldehyde is well known to cross-link proteins and DNAs, and known to be a major environmental risk factor. SSAO-mediated production of toxic aldehydes has been recently proposed to be related to pathological conditions such as vascular damage, diabetic complications, nephropathy, etc. Chronic administration of a large quantity of creatine can increase the production of formaldehyde, which may potentially cause serious unwanted side-effects.

Creatine↗
PubMed2000

New aspects to event-synchronous cancellation of ECG interference: an application of the method in diaphragmatic EMG signals.

An "event-synchronous interference canceller" (ESC) for cancellation of electrocardiographic (ECG) interference in diaphragmatic electromyographic (EMGdi) signals is addressed in this paper. ESC pursues the concept of the "event synchronous adaptive interference canceller" (ESAIC), which was proposed in [1] as a specific application of the well known "adaptive noise canceller" (ANC) paradigm, but ESC uses a simple adaptive gain control (AGC) instead of the complex adaptive filter of the ANC. The proposed ESC method is evaluated using both computer simulations and real EMGdi data, and its efficiency in interference cancellation is compared to that of ESAIC. Of particular interest is the result that the ESC can replace the ESAIC providing better performance as well as a considerable reduction of computational costs.

Biomedical Engineering↗
PubMed2000

Intra-atrial communication and control of atrial natriuretic factor (ANF) release.

Atrial natriuretic factor (ANF) release was studied in isolated perfused atria prepared from rats. When the vein-atrial junction (VAJ) was distended with an inflatable balloon, ANF release into the perfusate was greater in intact atria than in appendectomized atria. It was concluded that distention of the VAJ causes ANF release from the atrial appendage. A cascade experiment was then prepared whereby buffer from one isolated atrium perfused a second atrium. Although the VAJ of the first atrium could be distended by balloon, the atrial appendage was ligated so ANF was not secreted into the perfusate. The second atrium was intact, but no balloon was inserted. Despite the fact that there were no changes in intraluminal pressure, ANF secretion from the second atrium increased when the VAJ of the first atrium was distended. This response was blocked by the endothelin (ET) A receptor antagonist BQ-123. However, no distention-induced changes in ET-1 levels could be found in the perfusate from the first atrium. It is proposed that, in response to changes in distention of the VAJ, ANF is released remotely from the atrial appendage. The mediator does not appear to be ET-1 itself, but rather some factor that stimulates ET-1-induced ANF release within the tissue of the atrial appendage.

Animals↗
PubMed2000

Fluid extravasation from spleen reduces blood volume in endotoxemia.

We recently demonstrated that fluid is filtered out of the splenic circulation and into the lymphatic system. The current experiments were designed to investigate the importance of this route of fluid extravasation in endotoxemia. Lipopolysaccharide (LPS) was infused into conscious intact and splenectomized rats (150 microg x kg(-1). h(-1) i.v. for 18 h). In the intact rats, mean arterial pressure (MAP) fell from 101+/-2.4 to 88+/-3.9 mm Hg (n = 7) and then stabilized at about 90 mm Hg. Hematocrit rose from 41+/-0.9 to 45+/-0.4% at 40 min, at which time plasma volume had fallen from 4.7+/-0.12 to 4.0+/-0.05 ml/100 g body wt. In the splenectomized rats MAP did not fall and hematocrit did not rise. There also was no change in plasma volume, i.e., splenectomy prevented the hypotension and hemoconcentration customarily induced by LPS. In a second series of experiments, splenic arterial and venous blood flows were simultaneously measured in anesthetized rats infused with LPS (150 microg x kg(-1) x h(-1)). LPS increased splenic fluid efflux. We conclude that during endotoxemia the initial fall in circulating blood volume may be attributed to fluid extravasation from the splenic vasculature.

Animals↗
PubMed2000

Conditioned immunosuppressive effect of cyclophosphamide on delayed-type hypersensitivity response and a preliminary analysis of its mechanism.

In the present study, camphor odor and intraperitoneal (i.p.) injection of cyclophosphamide (CY) were used as conditioned stimulus (CS) and unconditioned stimulus (US), respectively. In the unconditioned group, mice were exposed to camphor odor for 1 h followed by an i.p. injection of CY (75 mg/kg). On the next day, the above CS/US association trial session was repeated followed by smearing dinitrochlorobenzene (DNCB) on mouse abdominal skin for sensitizing the animal for delayed-type hypersensitivity (DTH) response. Five days after DNCB sensitization, mice were exposed to camphor odor (1 h), followed by an i.p. injection of CY, and then DNCB was smeared on the left ear of mice for the challenge of DTH response. Both the left/right ear weight ratio and the activity of leukocyte migration inhibitory factor (LMIF) were used as the index of DTH response, which was done 24 h after DNCB challenge. In the conditioned group, the treatment was the same as that in the unconditioned group, except that normal saline was injected on day 5 instead of CY. Furthermore, in order to analyze the mechanism of the conditioned response (CR), the mouse serum from the conditioned group (CR serum) was injected into normal mice 6 h prior to DNCB challenge. Results showed that in the conditioned group, left/right ear weight ratio and LMIF activity were statistically lower than that in the DTH group, and there was no difference between conditioned and unconditioned groups. Thus, an animal model of conditioned immunosuppressive response had been established. The results also showed that after CR serum was injected into normal mice, DTH response was also significantly suppressed. However, if CR serum was treated with dialysis (10,000 molecular weight cut-off), the suppressive effect of CR serum on DTH response disappeared. Taken together, the data suggested that a chemical compound(s) in serum, with a molecular weight less than 10,000, was important in mediating the conditioned immunosuppressive response. This may be a very important molecule(s) that could be very critical to our understanding of the interaction between the central nervous system and immune function.

Animals↗
PubMed2000

Rejection of capillary wall background light in an on-column confocal fluorescence detector.

Minimization of the background arising from the capillary wall is of extreme importance in laser induced fluorescence on-column detection for capillary electrophoresis. A sensitive confocal fluorescence detection scheme is described. The intense capillary wall background light was effectively rejected by an adjustable precision slit in a confocal configuration. Rhodamine 640 was used as a standard fluorophore. Detection linearity was demonstrated over four orders of magnitude of concentration and the concentration detection limit was 3.38 x 10(-11) M.

Journal Article↗
PubMed2000

[Studies on the mechanisms of developmental toxicity of alcohol].

OBJECTIVE: To study the mechanisms of developmental toxicity in animals induced by ethyl alcohol. METHOD: Rat embryos of 9.5 days of gestation were exposed to different doses of ethyl alcohol in vitro. Postimplantation whole embryo culture and fluorescence polarization technique were used to investigate the effects of alcohol on embryo development and visceral yolk sac (VYS) membrane lipid fluidity. RESULT: 400 mg alcoho/L caused no significant differences to embryo development, organ morphological scores, polarization (Pr value) and lipid fluidity unit (LFU), as compared with the non-alcohol treated controls. 1,000 mg alcohol/L led to the decrease of scores of brain, VYS circle, neurotube, head length and heart, as well as DNA and Pr value; whereas LFU values were increased significantly. Above 2,000 mg alcohol/L, all indexes were decreased except LFU of VYS cell membrane. Alcohol significantly elevated lipid fluidity of VYS cell membrane. CONCLUSIONS: Alcohol causes development toxicity and teratogenisis in rats. Brain and VYS are the targets of alcohol effect. Its development toxicity is related with lipid fluidity and the VYS membrane damage.

Abnormalities, Multiple↗
PubMed2000

Overexpression of Bcl-2 partly inhibits apoptosis of human cervical cancer SiHa cells induced by arsenic trioxide.

OBJECTIVE: To study the biological effect of arsenic trioxide (As2O3) on human cervical cancer SiHa cells and SiHa cells overexpressing bcl-2 gene. METHODS: SiHa cells with overexpression of Bcl-2 (SiHa-Bcl2 cells) were established by transfecting SiHa cells with Bcl-2 expression vector. The sensitivities of SiHa and SiHa-Bcl2 cells to As2O3 were determined using MTT (Thiazolyl blue) reduction and colony forming ability assay, morphological analysis, flow cytometric analysis, DNA agarose gel electrophoresis, in situ cell death detection (TUNEL), Northern blot, RT-PCR and Western blot. RESULTS: As2O3 inhibited the growth of SiHa cells and induced G2/M arrest and apoptosis of the cells. RT-PCR and Western blot analysis revealed that As2O3 induced SiHa cell apoptosis possibly via inhibiting the expression of HPV16 E7 and decreasing the expression of c-myc. However, we found that SiHa-Bcl2 cells partly resisted As2O3 induced apoptosis, which might be related to the prevention of the down-regulation of HPV16 E7 and c-myc gene expression. Nevertheless, As2O3 at a high concentration could still induce apoptosis of SiHa-Bcl2 cells mainly via decreasing Bcl-2 expression and slightly inhibiting viral gene expression. CONCLUSION: As2O3 is an inducer of the apoptosis of human cervical carcinoma cells and the cells overexpressing Bcl-2 can partly resist As2O3 induced apoptosis, but the exact mechanism is unclear.

Antineoplastic Agents↗
PubMed2000

Changes in airway responsiveness and relative factors in asthma with remission at puberty.

OBJECTIVE: To elucidate the airway responsiveness and its relative factors in asthma with natural remission at puberty. METHOD: The airway responsiveness was evaluated by provocation of methacholine (PC20). Blood sIL-2R, IL-4 and IFN-gamma values in the cultural supernatant of mononuclear cells, eosinophil count, basophil count and basophil releasability were detected in 18 asthmatic cases with remission at puberty (group I), in 20 asthmatics without remission at puberty (group II), and in 30 healthy controls (group III). RESULT: The mean value of PC20 in group I was significantly lower than that in group III (P < 0.01), but still higher than that in group II (P < 0.01). The blood sIL-2R, and eosinophil counts dropped almost to those of group III, significantly lower than those of group II. IL-4 in the culture supernatant of mononuclear cells was similar to group III, but significantly lower than that in group II. However IFN-gamma was also similar to group III, significantly higher than that of group II. The basophil count and positive rate of human basophil degranulation test stimulated by mannitol with hyper-osmolarity were still abnormal, significantly higher than those of group III, and the basophil level was significantly related to the airway responsiveness. CONCLUSION: The asthmatics with remission at puberty have a certain degree of airway hyper-responsiveness that is related to the abnormality of basophil.

Adolescent↗
PubMed2000

[The effects of RA538 and antisense c-myc on cervical cancer cell lines with high expression of bcl-2 gene].

OBJECTIVE: To study the effects of recombinant adenovirus with RA538 or antisense c-myc insert on cervical cancer cell lines with high expression of bcl-2 gene. METHODS: Cervical cancer cell lines HeLa and SiHa were transduced with full length bcl-2 cDNA by lipofectin and cell clones with stable expression of bcl-2 were selected. They were then transfected with recombinant adenovirus containing RA538 (Ad-RA538), antisense c-myc (Ad-ASc-myc) or LacZ (Ad-LacZ) gene. Morphologic and molecular changes of the transfected cancer cells were examined by light microscopy, MTT, RT-PCR and Northern blot. RESULTS: The bcl-2 cDNA was successfully transferred into HeLa and SiHa cells. Two cell lines, called HeLa-bcl2 and SiHa-bcl2 with high expression of bcl-2 gene were generated. Ad-RA538 and Ad-ASc-myc transfection both could inhibit cell growth and induce apoptosis of HeLa and SiHa cells, and inhibit their expression of c-myc and bcl-2 genes. However, although Ad-RA538 and Ad-ASc-myc had some inhibitory effect on bcl-2 and c-myc gene expression by HeLa-bcl2 and SiHa-bcl2 cells, they could only slightly inhibit cell growth and weakly induce apoptosis. CONCLUSION: Ad-RA538 and Ad-ASc-myc can to certain extent inhibit cell growth and induce apoptosis of two cervical cancer cell lines. They have little such effect when these cell lines have over-expressed bcl-2 by transduction of exogenous bcl-2 gene.

Antineoplastic Agents↗
PubMed2000

[The effect of non-surgical periodontal therapy on blood sugar level of non-insulin dependent diabetes mellitus diabetics with periodontitis].

OBJECTIVE: To investigate the effect of periodontal therapy on blood sugar level of non-insulin dependent diabetes mellitus(NIDDM) diabetics with periodontitis. METHODS: Patients with unfavorable control of diabetes were selected from out patients of the first affiliated hospital of Sun Yat-sen University of Medical Science. The percentage of bleeding on probing, probing depth and glycosylated hemoglobin level were studied at baseline, four weeks and eight weeks after non-surgical treatment. RESULTS: The percentage of bleeding on probing and probing depth were significantly reduced in all the patients after treatment. The mean glycosylated hemoglobin level were significantly decreased in patients with advanced periodontitis while patients with moderate periodontitis showed no changes following therapy. CONCLUSIONS: The control of periodontal inflammation can improve metabolism to some extent in patients with diabetes mellitus, but the effect may relate to blood sugar level and periodontal conditions at baseline.

Aged↗