Biomedical subjects

Ping Yu

Publications and source records attributed to Ping Yu.

At least 37 records · Page 2Linked to original sources

PubMed2006

[MICA*008/A5.1 allele and HCMV infection in kidney transplanted donees of Hunan Han nationality].

OBJECTIVE: To investigate the relationship between MICA*008/A5.1 allele and human cytomegalovirus (HCMV) infection in kidney transplanted donees of Hunan Han nationality. METHODS: The MICA*008/A5.1 allele based on 91 kidney transplanted donees and 81 unrelated normal individuals of Han nationality in Hunan Province were analyzed by PCR/SSP assay. At the same time, anti-HCMV antibody IgM was detected in the serum by ELISA method. RESULTS: The positive rate of MICA*008/A5.1 allele was significantly higher in the control group (56.79%) than that in the kidney transplanted donee group (34.07%) (P <0.05). The infection rate of HCMV in those individuals whose genotype was MICA*008/A5.1 (-) was significantly higher than that in the MICA*008/A5.1(+). CONCLUSION: The individual whose genotype is MICA*008/A5.1 (+) is not liable to HCMV infection, but the individual whose genotype is MICA*008/A5.1 (-) is liable to HCMV infection.

Alleles↗

PubMed2006

[Abscopal effect on metastatic tumor induced by oncolytic virus of H101 combining with local heating].

BACKGROUND & OBJECTIVE: The abscopal effect on the tumors is a distant antitumor activity induced by local treatments. The study was to observe the induction of abscopal effect by the combination of H101 oncolytic virotherapy with local heating. METHODS: Five patients with histologically confirmed, surgically unresectable metastatic malignant tumors (2 nasopharyngeal carcinomas, 1 pulmonary carcinoma, 1 parosteal sarcoma and 1 bladder carcinoma) that had definitely failed to the conventional chemotherapy and radiotherapy or refused these therapies were enrolled in this experimental therapy. All patients were treated with local intra tumor injection of H101 (5x10(11) - 15x10(11) VP) combined with 60-min heating at 42 degrees C. RESULTS: Two patients were cured with complete regressions of both injected and non-injected tumors and have survived for a long period up to date. Three patients responded to the novel therapy variously and eventually died from the disease, who survived 29, 15 and 13 months, respectively. CONCLUSION: The abscopal antitumor effect could be induced by the combination of H101 local intratumoral injection with heating.

Adenocarcinoma↗

PubMed2006

Leukocytosis and retinoic acid syndrome in patients with acute promyelocytic leukemia treated with arsenic trioxide.

OBJECTIVE: To study the incidence of leukocytosis and retinoic acid (RA) syndrome in newly diagnosed and relapsed acute promyelocytic leukemia (APL) patients treated with arsenic trioxide (ATO). METHODS: Thirty patients with newly diagnosed or relapsed APL received ATO for remission induction at the dose of 10 mg/d. RA syndrome was defined when patient was with one or more of the following signs or symptoms: fever, dyspnea, serous cavity effusion, muscular pain, pulmonary infiltration, weight gain, or pulmonary infiltration on chest X-ray. RESULTS: Twenty-three (77% ) patients achieved complete remission, mean time to remission was 37.1 days. Leukocytosis was observed in 14 (47%) patients, mean time to leukocytosis was 12.7 days, median baseline leukocyte count for patients with leukocytosis was 3.1 x 10(9)/L, which was higher than that for patients who did not develop leukocytosis (2.6 x 10(9)/L, z = -2.635, P = 0.008). No other cytotoxic therapy was administered, and the leukocytosis resolved in all cases. The RA syndrome was observed in 9 (30%) patients, mean time to diagnose of RA syndrome was 13.9 days, median baseline leukocyte count for patients with RA syndrome was 3.6 x 10(9)/L, which was higher than that for patients who did not develop RA syndrome (2.6 x 10(9)/L, z = -1.909, P = 0.046). No patient died of RA syndrome. CONCLUSION: Leukocytosis and RA syndrome are associated with ATO and baseline leukocyte count respectively, and there is distinct link between leukocytosis and RA syndrome.

Adolescent↗

PubMed2006

Computer-based nursing documentation in nursing homes: A feasibility study.

The burden of paper-based nursing documentation has led to increasing complaints and decreasing job satisfaction amongst aged-care workers in Australian nursing homes. The automation of nursing documentation has been identified as one of the possible strategies to address this issue. A major obstacle to the introduction of IT solutions, however, has been a prevailing doubt concerning the ability and/or the willingness of aged-care workers to accept such innovation. This research investigates the attitudes of aged-care workers towards adopting IT innovation. Questionnaire survey were conducted in 13 nursing homes around the Illawarra and Sydney regions in Australia. The survey found that an unexpected 89.3% of participants supported the strategy of introducing electronic nursing documentation systems into residential aged-care facilities. 94.3% of them would use such a system depending on circumstances. Despite a shortage of computers in the workplace, which is a major barrier, this research provides strong evidence that care workers in residential aged-care facilities are willing to accept electronic nursing documentation practice and the uptake of information technology in residential aged-care is feasible in Australia.

Adult↗

PubMed2005

Stimulating lymphotoxin beta receptor on the dendritic cells is critical for their homeostasis and expansion.

The increased number of dendritic cells (DCs) inside lymphoid tissue may contribute to the enhanced priming of lymphocytes. The homeostasis of splenic DCs has mostly been attributed to their migration to the spleen via the chemokine microenvironment induced by lymphotoxin beta receptor (LTbetaR) signaling on splenic stromal cells. In this study we show that the lack of direct LTbetaR signaling on DCs is associated with the reduction of the number of DCs in the spleen independently of chemokine gradients. LTbetaR-/- mice have reduced DCs and reduced BrdU incorporation on DCs, and fewer DCs from LTbetaR-/- mice are detected in the spleen. Furthermore, increased expression of LIGHT (homologous to lymphotoxin, exhibits inducible expression, competes with herpesvirus glycoprotein D for herpes virus entry mediator on T cells) on T cells, a member of the TNF family (TNFSF14) and a ligand for LTbetaR, could dramatically increase the number of T cells and DCs, which leads to severe autoimmune diseases in a LTbetaR-dependent fashion. In vitro, LIGHT could directly promote accumulation of bone marrow-derived DCs. Furthermore, intratumor expression of LIGHT can dramatically expand DCs in situ, and inoculation of DCs into tumor tissues enhanced tumor immunity. Therefore, LTbetaR signaling on DCs is required for their homeostasis during physiology and pathological conditions, and increased LIGHT-LTbetaR interaction could stimulate DC expansion for T cell-mediated immunity.

Animals↗

PubMed2005

NK-cell activation by LIGHT triggers tumor-specific CD8+ T-cell immunity to reject established tumors.

Natural killer (NK) cells are generally reported as innate effector cells for killing virally infected and transformed cells. It is unclear how NK cells evoke adaptive immunity to eradicate tumors. We now demonstrate that the TNF superfamily member, LIGHT, known as TNFSF14 and a T-cell costimulatory molecule, is a critical ligand for the activation of NK cells. Herpesvirus entry mediator (HVEM) is expressed on NK cells, and its engagement with LIGHT mediates NK-cell activation. The expression of LIGHT inside tumors leads to rapid rejection in a NK-dependent manner. Both NK and CD8+ cells are essential but not sufficient for the rejection of tumors because mice lacking either population fail to reject the tumor. Interestingly, activated NK cells do not kill tumors directly but can facilitate the priming of tumor-specific CD8+ T cells in an IFN-gamma-dependent manner. Conversely, intratumor depletion of either NK cells or IFN-gamma during tumor progression disrupts CD8+ cell-mediated tumor rejection, suggesting that the tumor is the essential site for the crosstalk between NK and CD8+ cells. Furthermore, IFNG-deficient NK cells fail to effectively activate CD8+ T cells, suggesting IFN-gamma plays an important role in NK-mediated activation of cytotoxic T lymphocytes (CTLs). Our findings establish a direct role for LIGHT in NK activation/expansion and a critical helper role of activated NK cells in priming CD8+ T cells and breaking T-cell tolerance at the tumor site.

Animals↗

PubMed2005

Molecular films of water-miscible ionic liquids formed on glassy carbon electrodes: characterization and electrochemical applications.

This letter describes the formation and possible electrochemical applications of molecular films of water-miscible imidazolium-based ionic liquids (ILs) on glassy carbon (GC) electrodes. X-ray photoelectron spectroscopy (XPS) and electrochemical results indicate that the water-miscible ILs used in this study can interact with the GC electrode and form molecular films on the electrode surface. The formed molecular films are found to possess striking electrochemical properties such as electrocatalysis toward ascorbic acid (AA) and the capability to facilitate direct electron transfer of horseradish peroxidase (HRP). This demonstration would pave the way for new electrochemical applications of water-miscible ILs and is envisaged to be useful for the investigation of the electrochemical properties of water-miscible ILs in aqueous media provided the same counteranion is used as the supporting electrolyte.

Journal Article↗

PubMed2005

Endogenous kynurenate controls the vulnerability of striatal neurons to quinolinate: Implications for Huntington's disease.

Excessive activation of NMDA receptors results in excitotoxic nerve cell loss, which is believed to play a critical role in the pathophysiology of Huntington's disease (HD) and several other catastrophic neurodegenerative diseases. Kynurenic acid (KYNA), a neuroinhibitory tryptophan metabolite, has neuroprotective properties and may serve as an endogenous anti-excitotoxic agent. This hypothesis was tested in the striatum, using mice with a targeted deletion of kynurenine aminotransferase II (KAT II), a major biosynthetic enzyme of KYNA in the mammalian brain. On post-natal day (PND) 14, the striatum of mkat-2-/- mice showed a reduction in KYNA levels but contained normal concentrations of the metabolically related neurotoxins 3-hydroxykynurenine and quinolinic acid (QUIN). Intrastriatal injections of QUIN, a NMDA receptor agonist, caused significantly larger lesions in these immature mutant mice than in age-matched wild-type animals. This lesion enlargement was not observed when mkat-2-/- mice were acutely pre-treated with the kynurenine 3-hydroxylase inhibitor UPF 648, which counteracted the striatal KYNA deficit. Moreover, no increased vulnerability to QUIN was observed in 2-month-old mkat-2-/- mice, which present with normal brain KYNA levels. Intrastriatal injections of the non-NMDA receptor agonist kainate caused similar lesion sizes in both genotypes regardless of age. These results indicate that endogenous KYNA preferentially controls the vulnerability of striatal neurons to QUIN. Our data suggest that timely pharmacological interventions resulting in an up-regulation of brain KYNA levels may benefit patients suffering from HD or other neurodegenerative diseases.

Animals↗

PubMed2005

Development of a semi-quantitative food frequency questionnaire for middle-aged inhabitants in the Chaoshan area, China.

AIM: This paper aims to develop a data-based semi-quantitative food frequency questionnaire (SQFFQ) covering both urban and rural areas in the Chaoshan region of Guangdong Province, China, for the investigation of relationships between food intake and lifestyle-related diseases among middle-aged Chinese. METHODS: We recruited 417 subjects from the general population and performed an assessment of the diet, using a 3-d weighed dietary record survey. We employed contribution analysis (CA) and multiple regression analysis (MRA) to select food items covering up to a 90% contribution and a 0.90 R(2), respectively. The total number of food items consumed was 523 (443 in the urban and 417 in the rural population) and the intake of 29 nutrients was calculated according to the actual consumption by foods/recipes. RESULTS: The CA selected 233, 194, and 183 foods/recipes for the combined, the urban and the rural areas, respectively, and then 196, 157, and 160 were chosen by the MRA. Finally, 125 foods/recipes were selected for the final questionnaire. The frequencies were classified into eight categories and standard portion sizes were also calculated. CONCLUSION: For adoption of the area-specific SQFFQ, validity and reproducibility tests are now planned to determine how the combined SQFFQ performs in actual assessment of disease risk and benefit.

Body Mass Index↗

PubMed2005

Water exchange from the oxo-centered rhodium(III) trimer [Rh3(mu3-O)(mu-O2CCH3)6(OH2)3]+: a high-pressure 17O NMR study.

Water exchange from the oxo-centered rhodium(III) trimer, [Rh3(mu3-O)(mu-O2CCH3)6(OH2)3]+, was investigated using variable-temperature (272.8-281.6 K) and variable-pressure (0.1-200 MPa) 17O NMR spectroscopy. The exchange reaction was also monitored at three different acidities (pH = 1.8, 2.9, and 5.7) in which the molecule is in the fully protonated form (pKa = 8.3 (+/-0.2), I = 0.1 M, T = 298 K). The temperature dependence of the pseudo-first-order rate coefficient for water exchange yields the following kinetic parameters: k(ex)298 = 5 x 10(-3) s(-1), deltaH(double dagger) = 99 (+/-3) kJ mol(-1), and deltaS(double dagger) = 43 (+/-10) J K(-1) mol(-1). The enhanced reactivity of the terminal waters, some 6 orders of magnitude faster than water exchange from Rh(H2O)6(3+), is likely due to trans-labilization from the central oxide ion. Also, another contributing factor is the low average charge on the metal ions (+0.33/Rh). Variation of reaction rate with pressure results in a deltaV(double dagger) = +5.3 (+/-0.4) cm3 mol(-1), indicative of an interchange-dissociative (I(d)) pathway. These results are consistent with those published by Sasaki et al. who proposed that water substitution from rhodium(III) and ruthenium(III) oxo-centered trimers follows a dissociative mechanism based on highly positive activation parameters (Sasaki, Y.; Nagasawa, A.; Tokiwa-Yamanoto, A.; Ito, T. Inorg. Chim. Acta 1993, 212, 175-182).

Journal Article↗

PubMed2005

Specific T regulatory cells display broad suppressive functions against experimental allergic encephalomyelitis upon activation with cognate antigen.

To date, very few Ag-based regimens have been defined that could expand T regulatory (Treg) cells to reverse autoimmunity. Additional understanding of Treg function with respect to specificity and broad suppression should help overcome these limitations. Ig-proteolipid protein (PLP)1, an Ig carrying a PLP1 peptide corresponding to amino acid residues 139-151 of PLP, displayed potent tolerogenic functions and proved effective against experimental allergic encephalomyelitis (EAE). In this study, we took advantage of the Ig-PLP1 system and the PLP1-specific TCR transgenic 5B6 mouse to define a regimen that could expand Ag-specific Treg cells in vivo and tested for effectiveness against autoimmunity involving diverse T cell specificities. The findings indicate that in vivo exposure to aggregated Ig-PLP1 drives PLP1-specific 5B6 TCR transgenic cells to evolve as Treg cells expressing CD25, CTLA-4, and Foxp3 and producing IL-10. These Treg cells were able to suppress PLP1 peptide-induced EAE in both SJL/J and F(1) (SJL/J x C57BL/6) mice. However, despite being effective against disease induced with a CNS homogenate, the Treg cells were unable to counter EAE induced by a myelin basic protein or a myelin oligodendrocyte glycoprotein peptide. Nevertheless, activation with Ag before transfer into the host mice supports suppression of both myelin oligodendrocyte glycoprotein- and myelin basic protein peptide-induced EAE. Thus, it is suggested that activation of Treg cells by the cognate autoantigen is necessary for operation of broad suppressive functions.

Amino Acid Sequence↗

PubMed2005

Kinetic evidence for five-coordination in AlOH(aq)2+ ion.

Trivalent aluminum ions are important in natural bodies of water, but the structure of their coordination shell is a complex unsolved problem. In strong acid (pH < 3.0), Al(III) exists almost entirely as the octahedral Al(H2O)6(3+) ion, whereas in basic conditions (pH > 7), a tetrahedral Al(OH)(4- structure prevails. In the biochemically and geochemically critical pH range of 4.3 to 7.0, the ion structures are less clear. Other hydrolytic species, such as AlOH(aq)2+, exist and are traditionally assumed to be hexacoordinate. We show, however, that the kinetics of proton and water exchange on aqueous Al(III), coupled with Car-Parrinello simulations, support a five-coordinate Al(H2O)4OH2+ ion as the predominant form of AlOH(aq)2+ under ambient conditions. This result contrasts Al(III) with other trivalent metal aqua ions, for which there is no evidence for stable pentacoordinate hydrolysis products.

Journal Article↗

PubMed2005

Intratumor depletion of CD4+ cells unmasks tumor immunogenicity leading to the rejection of late-stage tumors.

Tumor environment can be critical for preventing the immunological destruction of antigenic tumors. We have observed a selective accumulation of CD4(+)CD25(+) T cells inside tumors. In a murine fibrosarcoma L(d)-expressing Ag104, these cells made up the majority of tumor-infiltrating lymphocytes at the late stage of tumor progression, and their depletion during the effector phase, rather than priming phase, successfully enhanced antitumor immunity. We show here that CD4(+)CD25(+) T cells suppressed the proliferation and interferon-gamma production of CD8(+) T cells in vivo at the local tumor site. Blockade of the effects of IL-10 and TGF-beta partially reversed the suppression imposed by the CD4(+) cells. Furthermore, local depletion of CD4(+) cells inside the tumor resulted in a change of cytokine milieu and led to the eradication of well-established highly aggressive tumors and the development of long-term antitumor memory. Therefore, CD4(+)CD25(+) T cells maintained an environment in the tumor that concealed the immunogenicity of tumor cells to permit progressive growth of antigenic tumors. Our study illustrates that the suppression of antitumor immunity by regulatory T cells occurs predominantly at the tumor site, and that local reversal of suppression, even at a late stage of tumor development, can be an effective treatment for well-established cancers.

Adoptive Transfer↗

PubMed2005

Multidrug resistance in Klebsiella pneumoniae MGH78578 and cloning of genes responsible for the resistance.

Klebsiella pneumoniae MGH78578, a clinical isolate, showed high level of resistance to many antimicrobial agents. We cloned genes responsible for drug resistance from chromosomal DNA of K. pneumoniae MGH78578 by shotgun method using Escherichia coli KAM32, a drug hypersensitive strain, as host. We obtained 43 hybrid plasmids that made host cells resistant to several antimicrobial agents. We classified them into 17 groups based on growth properties in the presence of each one of 9 antimicrobial agents and on restriction patterns of each hybrid plasmid. Analysis of the cloned genes must be very useful for investigation of major parts of multidrug resistance systems including multidrug efflux pumps in K. pneumoniae MGH78578 in which genome sequence is available.

Biological Transport↗

PubMed2005

Work practice changes caused by the introduction of a picture archiving and communication system.

We studied the acceptance of work practice changes six months after the introduction of a picture archiving and communication system (PACS) in New South Wales. A one-page questionnaire was developed to assess doctors' and nurses' acceptance of work practice changes. Over 100 subjects were surveyed and 76 responded. In all, 92% of participants worked in the intensive-care unit (ICU) or the emergency department (ED). The results showed that the PACS had received a high level of acceptance. The respondents would not like to return to a film-based practice. They were happy with the accessibility of images, especially when patients returned from an X-ray examination. At the time of survey, the doctors still had difficulty in remembering their user name and password. The users rarely or only sometimes used their own user names and passwords to log on the system. They were sometimes annoyed by the automatic time-out function. Nurses were happy that the PACS relieved their burden of searching for X-ray images for doctors. However, they distanced themselves from accessing the PACS, which they regarded as a doctors' tool.

Attitude of Health Personnel↗

PubMed2005

Methadone dosage and retention: an examination of the 60 mg/day threshold.

A National Institutes of Health (NIH) expert panel has mentioned a daily methadone dose of at least 60 mg as a best practice in methadone maintenance. The focus of this research is to estimate the percentage of outpatient methadone clients receiving this level of methadone and examine the association between treatment retention and level of methadone dosage as recommended by the NIH expert panel. A sample of 428 methadone clients discharged from methadone treatment facilities from the Alcohol and Drug Services Study (ADSS) was used, representing 109,973 methadone clients nationally. It was estimated that more than two-thirds of methadone clients nationally were receiving below 60 mg/day. While controlling for a number of client and organizational variables, a daily methadone dose of 60 mg/day or above was found to be associated with longer retention in treatment. Exploring factors affecting the utilization of the recommended daily methadone dose remains an important issue in effective delivery of methadone treatment.

Adult↗

PubMed2005

[Clinical observation of the lead discharging effect of paiqian chewing tablet].

OBJECTIVE: To observe the effect of paiqian chewing tablet (PQCT) on lead discharging and health in children. METHODS: Adopting self-control and inter-group control method, 94 children with blood lead level exceeding 100 microg/L were randomly divided into the observed group and the control group. The observation period for both groups was 30 days. RESULTS: At the 20th and 30th day of treatment, the urinary lead output in the observed group was significantly higher than that in the control group (P < 0.05, P < 0.01), and showed significant difference as compared with that before treatment (P < 0.05). Besides, the total amount of urinary lead discharging in the observed group was significantly more than that in the control group (P < 0.05). CONCLUSION: PQCT has markedly lead discharging improvement action with no influence on urinary calcium and zinc excretion. As all the routine indexes of blood and urine ranged within the normal extent, it demonstrated that PQCT was harmless to the health of observed individual.

Child↗

PubMed2005

[Report on 16 rare species of human chromosomal].

By examining the lymphocytic chromosomes of peripheral blood from patients with amenorrhea, spontaneous abortion and stillbirth history, .the 16 rare species of human chromosomal abnormal karyotypes were discovered. They were 46,XY,t(6;11)(q25;p15);46,XY,inv(3)(p25;q29);46,XY,t(7;18)(q10;p10);46,X,t(X;13)(q24;q14);46,XY,t(4;7)(q33;q22);46,XY,t(8;15)(q24;q15);46,XY,t(2;17)(q33;q25);46,XX,t(4;7)(q34;q11);46,XX,t(1;3)(p36;p23);46,XX,t(4;6)(q35;p11);46,X,inv(X)(q22;q28);46,XX,t(7;10)(p11;q26);46,XX,t(3;6)(p21;q23);46,XX,t(8;16)(p21;p13);46,XX,t(8;9)(q21;q34);46,XY,t(17;22)(q21;q11). Their clinical situation were described. Discussion on the relationship between the chromosomal aberrations and phenotype effect indicates the importance of chromosome karyotyping in patients with abnormal reproductive history.

Abortion, Habitual↗