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Yu Xu

Publications and source records attributed to Yu Xu.

At least 37 records · Page 2Linked to original sources
PubMed2006

Liquid chromatography/tandem mass spectrometry assay for the quantification of troxerutin in human plasma.

A simple, rapid, sensitive and specific liquid chromatography/tandem mass spectrometry method was developed and validated to quantify troxerutin in human plasma. The analyte and rutin, used as the internal standard, were analyzed on a Phenomenex Synergi Fusion RP column interfaced with a triple-quadrupole tandem mass spectrometer using positive electrospray ionization. Acetonitrile/water (20:80 v/v) was used as the isocratic mobile phase, with 0.1% formic acid in water. A simple sample preparation method of protein precipitation with perchloric acid was employed. The assay was linear over the concentration range 31.25-4000 pg/mL. Correlation coefficients generated by linear regression with a 1/x(2) weighting factor ranged from 0.9991 to 0.9996. The intra- and inter-day precision over the entire concentration range were less than 12.28%. The method was successfully applied to a pharmacokinetic study after oral administration of a 300 mg troxerutin drop pill to 18 healthy volunteers.

Adult↗
PubMed2006

[Clinical manifestation and laryngoscopic characteristics of laryngeal tuberculosis].

OBJECTIVE: To evaluate the clinical manifestations of laryngeal tuberculosis and its laryngoscopic characteristics. METHOD: Clinical analysis of 36 laryngeal tuberculosis cases confirmed pathologically was carried out retrospectively. RESULTS: The patients' ages ranged from 19 to 78 years old (median 39.5 years old). The male to female ratio was 1.8 to 1. The most frequent chief complaint was hoarseness (83.3%). The true vocal cord and the false vocal cord were usually found involved by fibrolaryngoscope observations. The lesions appearances were mainly the proliferation such as nodules or granules. The laryngostroboscopy demonstrated that the wave of the mucosa and vibration of the involved vocal cords were markedly reduced or disappeared. Among 24 patients with multiple lesions in the larynx, 19 (79.2%) had active pulmonary tuberculosis,while 9 (75.0%) had normal lung status among 12 patients with single lesions in the throat. All the patients received a full course of antituberculosis treatment. The results of the antituberculous medication was satisfactory in all 26 cases patients who can be followed up, while 10 cases were lost for the follow-up. CONCLUSIONS: The local clinical manifestations of laryngeal tuberculosis is nonspecific, while the whole manifestation is not apparent. The lesions commonly involve the true vocal cord and the false vocal cord. It can even occur without pulmonary tuberculosis.

Adult↗
PubMed2006

[Expression and activation of nuclear factor-kappaB in middle ear cholesteatoma].

OBJECTIVE: To explore the expression and activation of NF-kappaB in middle ear cholesteatoma. METHODS: The protein expression of NF-kappaB p65 in 21 middle ear cholesteatoma tissues and 8 normal external ear canal skin obtained in middle ear surgery were examined by immunohistochemistry; NF-kappaB DNA binding activity in these two kinds of tissues were also detected by electrophoretic motility shift assay (EMSA). The influence of cholesteatoma debris on the NF-kappaB DNA binding activity of HaCat cell were further analyzed. RESULTS: All epithelial cell of cholesteatoma revealed a relatively abundant plasma expression of NF-kappaB p65 protein, among which 12 cases showed nuclear positive expression. In contrast,the normal skin epithelium only revealed a sparse plasma distribution of NF-kappaB protein. The levels of NF-kappaB p65 protein expression in the epithelium of middle ear cholesteatoma tissue and normal skin were 0.168 +/- 0.051, 0.088 +/- 0.019 (t = 4.211, P < 0.01), respectively. The NF-kappaB DNA binding activities of cholesteatoma [(16.5 +/- 10.1)%] were also higher than those in normal skin [(1.38 +/- 1.24)%, t = 3. 600, P = 0.014]. The NF-kappaB DNA binding activity of HaCat cell increased when exposed to cholesteatoma debris in a dose dependent manner. CONCLUSION: NF-kappaB might be an important factor which was involved in the occurrence and development of cholesteatoma.

Adolescent↗
PubMed2005

Investigation of the measurement of murine airway hyperresponsiveness and the therapeutic effects of budesonide on ovalbumin sensitized and challenged mice.

BACKGROUND: Airway hyperresponsiveness (AHR) is one of the most important characteristics of asthma. This study investigated the parameters, by which assess the airway responsiveness under tidal ventilation. METHODS: Female BALB/c mice were sensitized and challenged with ovalbumin (OVA) (group A), and part of them were treated with budesonide aerosol (group B). All the mice were anaesthetized and mechanically ventilated. The values of tidal volume (Vt), airway pressure (PA), airway flow (F), expiratory lung resistance (RL) and dynamic compliance of the thorax and lung (CT-L) were recorded by the AniRes2003 animal lung function system. In addition, the expiratory volume in the first 0.1 second after the start of expiration (EV0.1) was obtained according to the flow-volume (F-V) curve. The maximal or minimal values of EV0.1, RL and CT-L were documented after each dose of methacholine (MCH) and compared with values from negative control group (group C). RESULTS: (1) When the dose of MCH reached 100 ng/g or 200 ng/g, the decrease of Vt in group A was much more significant than group C (P = 0.001, < 0.001 respectively), but not so between groups B and group C (P = 0.974, 0.362 respectively). (2) With the dose of 25, 50, 100 or 200 ng/g MCH, the decrease in percentage of EV0.1 in group A was much higher than group C (P = 0.012, 0.025, 0.001, 0.003 respectively), while that in group B showed no significant difference as compared with group C (P = 0.507, 0.896, 0.972, 0.785). (3) RL and CT-L: with the dose of 200 ng/g MCH, there was a statistically significant increase of RL in group A compared to group B or group C (P < 0.001, < 0.001 respectively), but no significant difference between groups B and C (P = 0.266). With doses of 100 ng/g and 200 ng/g MCH, there was a statistically significant decrease of CT-L in group A compared to group B (P = 0.001, = 0.001) and group C (P < 0.001, < 0.001 respectively), but no significant difference between groups B and C (P = 0.775, 0.310). (4) Histopathology: there were eosinophilic predominant peribronchial and perivascular inflammatory influx in murine lungs after OVA sensitizing and challenging, which could be counteracted by inhalation of budesonide in group B. CONCLUSIONS: The decline in EV0.1 in response to MCH challenge correlated with simultaneous changes in Vt, RL and CT-L, but more sensitively than all the other parameters. The decline in EV0.1 and inflammation in murine lung could be significantly alleviated by inhalation of nebulized budesonide solution, which indicated that EV0.1 to MCH is a valid measure of AHR in mice.

Airway Resistance↗
PubMed2005

High-performance field-effect transistors based on Langmuir-Blodgett films of cyclo[8]pyrrole.

We demonstrate the field-effect transistors (FETs) made of cyclo[8]pyrrole thin films prepared by the Langmuir-Blodgett (LB) method. The cyclo[8]pyrrole molecule possesses a 30-pi-electron system and narrower highest-occupied molecular orbital-lowest-unoccupied molecular orbital energy gap (0.63 eV), forms a stable, reproducible monolayer at the air-water interface, and transfers onto a substrate with a nearly unity transfer ratio and face-to-face configuration due to its strong pi-pi interaction. The LB films are uniform characterized by atomic force microscopy and in ordered form confirmed by X-ray diffraction. The FET exhibited high performances with one of the highest hole mobilities (0.68 cm2 V(-1) s(-1)) for thin-film transistors and a high on/off ratio, implying a promising material in the FET family.

Journal Article↗
PubMed2005

Development of a liquid chromatography/tandem mass spectrometry assay for the quantification of rabeprazole in human plasma.

A simple and sensitive liquid chromatography/tandem mass spectrometry method, employing electrospray ionization, has been developed and validated to quantify rabeprazole in human plasma using omeprazole as the internal standard. The method was validated to demonstrate the specificity, lower limit of quantification, accuracy, and precision of measurements. Selected reaction monitoring was specific for rabeprazole and omeprazole (the internal standard, IS); no endogenous materials interfered with the analysis of rabeprazole and IS from blank plasma. The assay was linear over the concentration range 0.2-200 ng/mL using a 2 microL aliquot of plasma. The correlation coefficients for the calibration curves ranged from 0.9988-0.9994. The intra- and inter-day precision, calculated from quality control samples, were less than 6.65%. A mixture of methanol and water (50:50) was used as the isocratic mobile phase, with 0.1% of formic acid in water, that did not affect the stability of rabeprazole or IS. A simple sample preparation method of protein precipitation with methanol was chosen. The method was employed in a pharmacokinetic study after oral administration of 20 mg rabeprazole to 24 healthy volunteers.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2005

Cancer risk factors of Vietnamese Americans in rural south Alabama.

PURPOSE: To identify aggregate-specific cancer risk factors of Vietnamese Americans in south Alabama and present a comparison with available national data and Healthy People 2010 targets. DESIGN: Cross-sectional survey. METHODS: A convenience sample of 284 Vietnamese community residents 18 years and over completed an investigator-designed questionnaire. Data were analyzed using descriptive correlational analysis. FINDINGS: Aggregate-specific cancer risk factors included high prevalence of hepatitis, high smoking and drinking rates in men, extended sun exposure without protection, knowledge deficit of cancer and cancer screenings, and low cancer screening rates. Educational level was significantly related to many cancer risk factors. CONCLUSIONS: Significant cancer risk factors exist in the target population in comparison to available national data and Healthy People 2010 targets. More focused cancer prevention and early detection efforts should be initiated for this underserved population. Future research is needed to (a) determine the effect of acculturation on cancer risk factors and (b) develop culturally appropriate interventions to improve the effectiveness of cancer prevention and early detection interventions in this subgroup of Asian Americans.

Acculturation↗
PubMed2005

One size doesn't fit all: ethics of international nurse recruitment from the conceptual framework of stakeholder interests.

This theoretical study examines the ethics of international nurse recruitment from the conceptual framework of stakeholder interests. It argues that there are stakeholders at individual, institutional, national and international levels, with overlapping but, more often, different or even conflicting interests. Depending on the interests of given stakeholders, different conclusions regarding the ethics of international nurse recruitment may be reached. There is no right or wrong with these varying ethical positions because they reflect different beliefs and philosophies that are not amenable to value judgment. To illustrate and support this line of argument, this article analyzes the underpinnings of two ethical standards published by the International Council of Nurses and the UK Department of Health. In addition, a case study on China augments the argument by demonstrating limitations of the one-size-fits-all approach to the issue. The most important question in understanding and evaluating the ethical standards of international nurse recruitment is to know whose interests they are designed to represent and protect.

Career Mobility↗
PubMed2005

Intercultural communication in nursing education: when Asian students and American faculty converge.

In the context of globalization and changing American demographics, it is becoming increasingly important to understand and communicate effectively with people from diverse cultural and racial/ethnic backgrounds. This article applies the framework of cultural variability and intercultural communication research literature to examine and highlight the different communication behaviors of Asians and non-Asians in the United States. The meanings of various verbal and nonverbal behaviors of Asian students are examined to clarify their communication patterns. Culture-based assumptions are identified, and measures to improve intercultural communication in nursing education are provided.

Asia↗
PubMed2005

What if your nursing student is from an Asian culture?

Nursing faculty are educating an increasing number of Asian and Asian American students. There is a paucity of literature on how to facilitate their growth into professional nurses given their unique cultural differences. In order to optimize their educational experience, nursing faculty need to have a working knowledge of the cultural underpinnings of Asian American students. Building on two real scenarios, this article provides footnotes for understanding the rationales of the behaviors of Asian and Asian American students. The Cultural Assessment Model by Giger and Davidhizar (2004) provides the framework for the analysis. Based on this cultural knowledge, strategies and tips for improving communication with Asian and Asian American students are presented.

Asian↗
PubMed2005

[The relationship between perennial allergic rhinitis and chronic sinusitis].

OBJECTIVE: To observe the incidence rate of chronic sinusitis in the patients with perennial allergic rhinitis, and explore the possible etiology of sinusitis. METHOD: Fifty-seven patients were examined with endoscope and CT scan. RESULT: Of the 57 patients, 18 (32%) patients had chronic sinusitis, among which 17 patients had different kinds and different extents of anatomy abnormalities of nose cavity including deviation of nasal septum, concha bullosa, hypertrophy of uncinate process, paradoxical curvature of middle turbinate, etc. Thirty-nine patients didn't complicated with chronic sinusitis, among which only 7 patients had anatomy abnormalities of nose cavity. CONCLUSION: Anatomy abnormalities of nose cavity may be the basic etiology of sinusitis in patients with perennial allergic rhinitis; The edema of nasal mucous and the change of nasal discharge caused by perennial allergic rhinitis may be the triggering factor of chronic sinusitis. Both of these two factors are involved in the pathogenesis of sinusitis.

Adolescent↗
PubMed2004

Analysis of five differentially expressed gene families in fast elongating cotton fiber.

Using the suppression subtractive hybridization method, we isolated five gene families, including proline-rich proteins (PRPs), arabinogalactan proteins (AGPs), expansins, tubulins and lipid transfer proteins (LTPs), from fast elongating cotton fiber cells. Expression profile analysis using cDNA array technology showed that most of these gene families were highly expressed during early cotton fiber developmental stages (0 C20 days post anthesis, DPA). Many transcripts accumulated over 50-fold in 10 DPA fiber cells than in 0 DPA samples. The entire gene family --AGP, together with 20 individual members in other 4 gene families, are reported in cotton for the first time. Accumulation of cell wall proteins, wall loosening enzymes, microtubules and lipid transfer protein may contribute directly to the elongation and development of fiber cells.

Amino Acid Sequence↗
PubMed2004

Photochemotherapy inhibits angiogenesis and induces apoptosis of endothelial cells in vitro.

BACKGROUND: Photochemotherapy has long been used in the treatment of psoriasis; however, its mechanism has not been completely elucidated. Psoriasis is now regarded as an angiogenesis-related disease. Recent studies indicated that the inhibition of angiogenesis by photochemotherapy could be an underlying mechanism. It was found that photochemotherapy can downregulate the expression of angiogenic factors in keratinocytes. However, the direct effect of photochemotherapy on endothelial cells has not been studied. METHODS: In this study, we determined the effect of photochemotherapy on the proliferation of human microvascular endothelial cells through MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and cell cycle analysis. The migration assay and in vitro tube formation assay were used to investigate the migration properties and tube formation ability of human microvascular endothelial cells after psoralen plus UVA (PUVA) treatment. The apoptosis of endothelial cells elicited by photochemotherapy was also analyzed with fluorescence-activated cell sorting analysis (FACS). RESULTS: UVA (0.8-5.0 J/cm(2)) irradiation with the presence of 8-methoxypsoralen (8-MOP) (300 ng/ml) resulted in a dose-dependent reduction in the cell viabilities of endothelial cells. FACS data showed an accumulation of cells in G0/G1 phase of cell cycle and apoptotic features of cell death after UVA irradiation with psoralen. The migration properties and tube formation ability of endothelial cells were dramatically inhibited by photochemotherapy. CONCLUSION: Our results showed that photochemotherapy inhibits angiogenesis and induces apoptosis of human microvascular endothelial cells in vitro, which may be a possible mechanism of photochemotherapy in the treatment of psoriasis.

Analysis of Variance↗
PubMed2004

[Analysis of bacterial culture and C. pneumoniae DNA detection of chronic pharyngitis].

OBJECTIVE: To research the pathogenic microorganism characters of chronic pharyngitis. METHOD: Samples taken from pharyngeal swab from patient with chronic pharyngitis were routinely cultured; mp-DNA were detected by polymerase chain reaction (PCR). RESULT: Of all the cases, 5 patients were DNA(+), among which 3 patients got obvious effect after 2 weeks treatment. The bacterial abnormally was present in 15 patients (31.5%), among which 6 patients got obvious effect and 2 patients got no effect after 2 weeks treatment. CONCLUSION: The pathogenic abnormally may be present in some patients with chronic pharyngitis, most of which appeared to be an internal disorder of the proper microflores. C. pneumoniae may be an aetiological agent for chronic pharyngitis. An appropriate antimicrobial treatment should be considered in some cases.

Adolescent↗
PubMed2003

Effects of melatonin on the expression of iNOS and COX-2 in rat models of colitis.

AIM: To investigate the effects of melatonin (MT) on the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in rat models of colitis. METHODS: Healthy adult Sprague-Dawlay (SD) rats of both sexes, weighing 280+/-30 g, were employed in the present study. The rat models of colitis were induced by either acetic acid or 2,4,6-trinitrobenzene sulfonic acid (TNBS) enemas. The experimental animals were randomly divided into melatonin treatment and model control group that were intracolicly treated daily with melatonin at doses of 2.5, 5.0, 10.0 mg/kg(-1) and equal amount of saline respectively from 24 h following induction of colitis in rats inflicted with acetic acid enema and the seventh day in rats with TNBS to the end of study. A normal control group of rats treated with neither acetic acid nor TNBS but saline enema was also included in the study. On the 28(th) day of the experiment, the rat colon mucosal damage index (CDMI) was calculated, and the colonic prostaglandin E(2) (PGE(2)), nitric oxide (NO), as well as the iNOS and COX-2 expression were also determined biochemically or immunohistochemically. RESULTS: CDMI increased to 2.87+/-0.64 and 3.12+/-1.12 respectively in rats treated with acetic acid and TNBS enema, which was in accordance with the significantly elevated colonic NO and PGE(2) contents, as well as the up-regulated colonic iNOS and COX-2 expression in both of the two rat models of colitis. With treatment by melatonin at the doses of 5.0 and 10.0 mg/kg(-1), CDMI in both models of rat colitis was significantly decreased (P<0.05-0.01), which accorded synchronously and unanimously with the reduced colonic NO and PGE(2) content, as well as the down-regulated expression of colonic iNOS and COX-2. CONCLUSION: Melatonin has a protective effect on colonic injury induced by both acetic acid and TNBS enemas, which is probably via a mechanism of local inhibition of iNOS and COX-2 expression in colonic mucosa.

Animals↗
PubMed2003

[Possible role of transforming growth factor alpha on the cholesteatoma growth regulation].

OBJECTIVE: To investigate the mode of expression and distribution of transforming growth factor alpha in middle ear cholesteatoma. METHOD: The specimens from the cholesteatoma tissue of 32 cases and the normal external ear skin of 10 cases were examined by immunohistochemical S-P method and computer image analysis. RESULT: In cholesteatoma epithelium staining for TGF alpha was consistently stronger than that in normal epithelium. The mean absorbance of the two epithelial tissue is 2.431 +/- 0.587 and 1.463 +/- 0.147 respectively, revealing a significant difference. Some immune cells infiltrating the stroma of cholesteatoma also stained positively for TGF alpha. CONCLUSION: These data suggested that an autocrine and paracrine stimulation of the squamous epithelium of cholesteatoma by TGF might contribute to its hyperproliferation.

Adolescent↗