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K Wang

Publications and source records attributed to K Wang.

At least 55 records · Page 3Linked to original sources
PubMed2004

Measurements of CP-violating asymmetries in B0-->K(0)(s)pi(0) decays.

We present a measurement of the time-dependent CP-violating (CPV) asymmetries in B0-->K(0)(S)pi(0) decays based on 124x10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. In a sample containing 122+/-16 signal decays, we obtain the magnitudes of the direct CPV asymmetry CK(0)(S)(pi(0))=0.40(+0.27)(-0.28)+/-0.09 and of the CPV asymmetry in the interference between mixing and decay SK(0)(S)(pi(0))=0.48(+0.38)(-0.47)+/-0.06 where the first error is statistical and the second systematic.

Journal Article↗
PubMed2004

Bound on the ratio of decay amplitudes for -B0-->J/psiK*0 and B0-->J/psiK*0.

We have measured the time-dependent decay rate for the process B-->J/psiK(*0) (892) in a sample of about 88x10(6) Upsilon(4S)-->B(-)B decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. In this sample we study flavor-tagged events in which one neutral B meson is reconstructed in the J/psiK(*0) or J/psi(-)K(*0) final state. We measure the coefficients of the cosine and sine terms in the time-dependent asymmetries for J/psiK(*0) and J/psi(-)K(*0), find them to be consistent with the standard model expectations, and set upper limits at 90% confidence level (C.L.) on the decay amplitude ratios |A((-)B(0)-->J/psiK(*0))|/|A(B0-->J/psiK(*0))|<0.26 and |A(B0-->J/psi(-)K(*0))|/|A((-)B(0)-->J/psi(-)K(*0))|<0.32. For a single ratio of wrong-flavor to favored amplitudes for B0 and (-)B(0) combined, we obtain an upper limit of 0.25 at 90% C.L.

Journal Article↗
PubMed2004

Measurement of the time-dependent CP asymmetry in the B0-->phiK0 decay.

We present a measurement of the time-dependent CP asymmetry for the neutral B-meson decay B0-->phiK0. We use a sample of approximately 114 x 10(6) B-meson pairs taken at the Upsilon(4S) resonance with the BABAR detector at the PEP-II B-meson factory at SLAC. We reconstruct the CP eigenstates phiK0S and phiK0L, where phi-->K+K-, K0S-->pi+pi-, and K0L is observed via its hadronic interactions. The other B meson in the event is tagged as either a B0 or Bbar0 from its decay products. The values of the CP-violation parameters are SphiK=0.47+/-0.34(stat)+0.08-0.06(syst) and CphiK=0.01+/-0.33(stat)+/-0.10(syst).

Journal Article↗
PubMed2004

Glutamate evoked neck and jaw muscle pain facilitate the human jaw stretch reflex.

OBJECTIVE: Although pain and neuromuscular function are clearly linked in several clinical conditions manifested in the craniofacial and cervical regions, it is unclear if pain in these regions influences reflexly evoked activity in the jaw or neck muscles in humans. The aim of the present study was to test the effects of glutamate-evoked jaw or neck muscle pain on the jaw stretch reflex recorded in both jaw and neck muscles. METHODS: Nineteen healthy men participated in the study. Electromyographic (EMG) recordings were made from the left masseter (MAL) and right masseter (MAR) muscles and the right sternocleidomastoid (SCM) and splenius (SP) muscles. Glutamate (1 M) or isotonic saline was injected into the MAR or right SP in random order and then the other solution was injected 1-3 weeks later. Pain intensity was scored on a 10 cm visual analogue scale. Stretch reflexes were evoked by standardized jaw stretches before, during and 15 min after the end of the experimental muscle pain. Twenty trials were averaged in each condition. RESULTS: Pain evoked by MAR or SP glutamate injections was associated with a significant increase in the stretch reflex amplitude recorded in both MAR and SCM. The onset and offset times and duration of the stretch reflex did not change in any muscle during the various pain conditions. Injection of isotonic saline into the MAR or SP did not produce any significant change in the reflex parameters in any of the muscles. CONCLUSIONS: The results indicate the close interplay between the craniofacial and cervical regions in the neuromuscular changes that may result from musculoskeletal pain in either region. SIGNIFICANCE: The changes in neuromuscular activity documented in this study may be involved in the clinical occurrence of altered muscle activity in the orofacial and cervical regions as a result of deep tissue trauma and pain.

Adult↗
PubMed2004

Safety of mycophenolate mofetil versus azathioprine in renal transplantation: a systematic review.

INTRODUCTION: To evaluate the safety of mycophenolate mofetil (MMF) versus azathioprine (Aza) in renal transplantation, we compared their side effects using evidence-based methods. METHODS: Medline, Embase, Cochrane library, and Chinese Biomedicine database (CBM) were searched to select randomized clinical trials that had one group using MMF and another group using Aza as an immunosuppressive drugs. Safety analysis consist of the following factors: diarrhea, abdominal pain, vomiting, nausea, constipation, CMV infection, leukopenia, anemia, thrombocytopenia or skin malignancy. RevMan 4.11 software was used for the systematic review analysis. RESULT: Twenty trials including 6387 patients were identified. The diarrhea incidence with MMF (3 g/d) was higher than for Aza at 1 and 3 years (P < .05). Diarrhea on MMF (2 g/d) was higher than for Aza within 6 months (P < .05). CMV infection incidence on MMF (3 g/d) was higher than for Aza's at 3 years (P < .05), but MMF (2 g/d) did not show a statistical significance compared with Aza. Leukopenia incidence on MMF (3 g/d) was higher than that on Aza, whereas the incidence with MMF (2 g/d) was not significantly different from Aza. Skin malignancy incidence showed no statistical difference between MMF 3 g/d, MMF 2 g/d, or Aza. CONCLUSION: The use of MMF is associated with slight increases in gastrointestinal adverse effects, some hematologic adverse events, and CMV infections compared with Aza. Larger sample sizes of randomized controlled trials are needed to evaluate the safety of MMF.

Azathioprine↗
PubMed2004

Efficacy of mycophenolate mofetil versus azathioprine after renal transplantation: a systematic review.

INTRODUCTION: Our objective was to evaluate the efficacy of mycophenolate acid (MMF) versus azathioprine (AZA) after renal transplantation. MATERIALS AND METHODS: The following electronic databases were searched: Medline, Embase, Cochrane library, and Chinese Biomedicine database (CBM). Randomized controlled trials (RCTs) were subjected to Revman 4.11 for statistical analyses. RESULTS: Twenty-three RCTs were identified to compare MMF and AZA for antirejection, prophylaxis after renal transplantation. The data showed that MMF (2 g/d) was more beneficial than AZA to improve graft and long-term patient survivals, but there was no statistical differences between MMF (3 g/d) and AZA. Whether at 6 months or at 1 year after renal transplantation, the use of MMF (2 g/d) or MMF (3 g/d) markedly reduced the incidence of biopsy-proven rejection. CONCLUSION: Compared with AZA, MMF is a more potent immunosuppressive drug, that is more efficient in reducing the incidence of acute rejection episodes after renal transplantation. MMF can improve the graft and patient survival rate. The 2 g per day dosage is more acceptable.

Azathioprine↗
PubMed2004

Alleviating ischemia-reperfusion injury in aged rat liver by induction of heme oxygenase-1.

BACKGROUND: Heme oxygenase-1 (HO-1), a cytoprotective protein, may be important in ameliorating hepatic ischemia-reperfusion (I/R) injury, a critical factor in the dysfunction of the aged liver after transplantation. METHODS: We used hemin to overexpress HO-1 and analyze its effects in a model of I/R in aged livers used for orthotopic transplantation. RESULTS: The SGOT levels in the hemin group were significantly lower than those of the saline treatment group. Hemin liver grafts showed markedly fewer apoptotic (TUNEL+) liver cells after reperfusion compared with the controls. The plasma nitric oxide levels in the hemin group were significantly lower than those in the control group. Unlike untreated or hemin + Znpp-treated orthotopic liver transplant controls, iNOS expression in the hemin group was almost absent at 12 and 24 hours, after reperfusion. In contrast, eNOS was comparable in hemin and saline orthotopic liver transplants. The increased levels of Bcl-2 expression compared with saline controls were most pronounced at 12 hours after transplantation. In contrast, caspase 3 was lower at 24 hours among the hemin-pretreated group compared with saline-treated liver transplant controls. CONCLUSIONS: HO-1 alleviated the I/R injury in the aged liver by suppressing local expression of inducible nitric oxide synthase and by modulating pro- and antiapoptotic pathways.

Aging↗
PubMed2004

Clustering of death receptors in lipid rafts initiates neutrophil spontaneous apoptosis.

Neutrophils die by apoptosis spontaneously within 12-24 h of their release from the bone marrow. The mechanism regulating entry of neutrophils into apoptosis at the end of their life-span is currently under debate. Our data suggest that neutrophil apoptosis involves a novel mechanism of caspase 8 activation that is indirectly regulated by accumulation of reactive oxygen species. We detected early activation of caspase 8 upstream of caspase 3 activation, suggesting death receptor signalling. The CD95 DISC (death-inducing signalling complex) was detected in neutrophils, but blocking antibodies to death receptors did not inhibit apoptosis, suggesting a novel mechanism for caspase 8 activation. Death receptor clustering in ceramide-rich lipid rafts is thought to be an early event in their signalling, so we investigated the role of ceramide generated by ASM (acid sphingomyelinase) in neutrophil apoptosis. Ceramide was generated early in neutrophil apoptosis, and ASM activity was required for neutrophil apoptosis. Moreover, neutrophil apoptosis was significantly delayed in ASM(-/-) mice compared with their wild-type littermates. CD95 DISC components were present in lipid rafts in neutrophils, and were progressively clustered in cultured neutrophils. Generation of ceramide was blocked by desferrioxamine, suggesting that hydroxyl radicals are important for the activation of ASM. This observation was in line with our earlier observation of a precipitous drop in reduced glutathione in the aging neutrophil.

Animals↗
PubMed2004

A note on the asymptotic properties of affected-sib-pair linkage tests.

This article concerns the asymptotic properties of linkage tests for affected-sib-pair data under the null hypothesis of no linkage. We consider a popular single-locus analysis model where the unknown parameters are the disease allele frequency, the three penetrances for the three genotypes at the disease locus, and the recombination fraction between the marker locus and the disease locus. These parameters are completely confounded under the null hypothesis of no linkage. We show that 1) If the total variance of the trait (i.e., the additive variance plus the dominance variance) is "separated" from 0, then the likelihood ratio statistic has an asymptotic 0.5chi(2) (0)+ 0.5chi(2) (1) distribution; 2) If the prevalence of the trait is "separated" from 0 and the recombination fraction is fixed at 0, then the likelihood ratio statistic has an asymptotic distribution which is a mixture of chi(2) (0), chi(2) (1) and chi(2) (2). The implications of these results are discussed.

Gene Frequency↗
PubMed2004

DNA-based prenatal diagnosis in a Chinese family with xeroderma pigmentosum group A.

BACKGROUND: Xeroderma pigmentosum (XP) is a group of autosomal recessive diseases characterized by hypersensitivity to ultraviolet rays. Among its eight complementation groups, XP group A (XPA) is the most severe type. The XPAC gene has been identified as the defective gene in XPA patients. OBJECTIVES: To examine genomic DNA from a Chinese family with XPA, to determine the XPAC mutation and, after genetic counselling, to undertake DNA-based prenatal diagnosis in a subsequent pregnancy. METHODS: Fetal DNA was extracted from amniotic fluid and used to amplify exon 5 of XPAC containing the potential mutation. Direct sequencing and restriction endonuclease digestion were used for prenatal diagnosis. RESULTS: We identified a homozygous nonsense XPAC mutation of 631C-->T, which results in an R211X mutation in XPA protein, in the proband. Both her parents are heterozygous. Prenatal diagnosis demonstrated a heterozygous sequence predicting an unaffected child, and a healthy girl was born. CONCLUSIONS: These data provide the first example of a DNA-based prenatal test for genodermatosis in China.

Child, Preschool↗
PubMed2003

Truncated negative binomial mixed regression modelling of ischaemic stroke hospitalizations.

A zero-truncated negative binomial mixed regression model is presented to analyse overdispersed positive count data. The study is motivated by the determination of pertinent risk factors associated with ischaemic stroke hospitalizations. Random effects are incorporated in the linear predictor to adjust for inter-hospital variations and the dependency of clustered observations using the generalized linear mixed model approach. The method assists hospital administrators and clinicians to estimate the number of subsequent readmissions based on characteristics of the patient at the index stroke. The findings have important implications on resource usage, rehabilitation planning and management of acute stroke care.

Binomial Distribution↗
PubMed2003

Effects of TMJ anesthesia and jaw gape on jaw-stretch reflexes in humans.

OBJECTIVE: To study the roles of afferent sensory inputs in the temporomandibular joint (TMJ) and of muscle length in the modulation of the jaw-stretch reflex in humans. METHODS: Reflexes were evoked in both the masseter and temporalis muscles under standardized conditions in 11 young women. The study was performed in two sessions; experimental conditions were jaw gape and injection of local anesthetics. For jaw gape, 4, 14, and 24 mm were used in random order. One milliliter TMJ injections (carbocaine, 10 mg/ml, versus isotonic saline, 0.9%) were given in a randomized, double blind manner. When a participant received carbocaine during the first session, isotonic saline was injected during the second one. A total of 480 reflexes were evoked in every participant. RESULTS: No significant differences were found between carbocaine and isotonic saline. ANOVA and post hoc paired t tests did show, however, a significant effect of jaw gape for the left masseter and anterior temporalis muscles, with the 14 mm gape having the highest amplitude. CONCLUSIONS: Blocking the afferent sensory input (including the mechanoreceptors) from the TMJ seems to have no influence on the sensitivity of the human jaw-stretch reflex. Instead, muscle spindles are the most likely receptors to be responsible for the reflex modulation that was observed in the present study.

Adult↗
PubMed2003

Factors influencing hospitalisation of infants for recurrent gastroenteritis in Western Australia.

OBJECTIVE: To determine factors affecting length of hospitalisation of infants for recurrent gastroenteritis using linked data records from the Western Australia heath information system. METHODS: A seven-year retrospective cohort study was undertaken on all infants born in Western Australia in 1995 who were admitted for gastroenteritis during their first year of life (n = 519). Linked hospitalisation records were retrieved to derive the outcome measure and other demographic variables for the cohort. Unlike previous studies that focused mainly on a single episode of gastroenteritis, the durations of successive hospitalisations were analysed using a proportional hazards model with correlated frailty to determine the prognostic factors influencing recurrent gastroenteritis. RESULTS: Older children experienced a shorter stay with an increased discharge rate of 1.9% for each month increase in admission age. An additional co-morbidity recorded in the hospital discharge summary slowed the adjusted discharge rate by 46.5%. Aboriginal infants were readmitted to hospital more frequently, and had an adjusted hazard ratio of 0.253, implying a much higher risk of prolonged hospitalisation compared to non-Aborigines. CONCLUSIONS: The use of linked hospitalisation records has the advantage of providing access to hospital-based population information in the context of medical informatics. The analysis of linked data has enabled the assessment of prognostic factors influencing length of hospitalisations for recurrent gastroenteritis with high statistical power.

Female↗
PubMed2003

Factors affecting length of hospitalization of infants and children for recurrent gastroenteritis in Western Australia.

AIM: Aboriginal infants in Western Australia (WA) have much higher rates of hospitalization for gastroenteritis than do their non-Aboriginal peers. The aim of this 7-y retrospective study was to investigate the factors affecting the duration of hospitalizations due to recurrent gastroenteritis in WA. METHODS: All infants born in WA in 1995 and 1996 who had indexed gastroenteritis admissions during their first year of life (n = 1009) were followed until 31 May 2002. Linked hospitalization and birth records were retrieved to derive the outcome measures, associated co-morbidities and other demographic variables. A proportional hazards frailty model was then used to determine factors influencing discharge from hospital for the study cohort. RESULTS: Aboriginal patients were readmitted to hospital more frequently and stayed in hospital more than twice as long as non-Aborigines. Factors that slowed the rate of discharge from hospital included Indigenous status and the presence of coexisting conditions such as dehydration, sugar intolerance, failure to thrive and iron-deficiency anaemia. CONCLUSION: Gastrointestinal infections are common illnesses in infants and children, particularly for those who live in overcrowded and unhygienic conditions. Coexisting morbidities including undernutrition, nutrient deficiencies, other infections and gastrointestinal carbohydrate intolerance contribute to prolonged and recurrent hospitalization. Multifaceted clinical, disease prevention and health/hygiene promotion are needed to lessen the burden of these infections.

Anemia, Iron-Deficiency↗
PubMed2002

A hierarchical Poisson mixture regression model to analyse maternity length of hospital stay.

Inpatient length of stay (LOS) is often considered as a proxy of hospital resource consumption. Using statewide obstetrical delivery data, a two-component Poisson mixture model provides a reasonable fit to the heterogeneous LOS distribution. Adopting the generalized linear mixed model (GLMM) approach, random effects are introduced to the two-component Poisson mixture regression model to account for the inherent correlation of patients clustered within hospitals. An EM algorithm is developed for the joint estimation of regression coefficients and variance component parameters. Related diagnostic measures for assessing model adequacy are derived. When applying the method to analyse maternity LOS, appropriate risk factors for the short-stay and long-stay subgroups can be identified from the respective Poisson components. In addition, predicted random hospital effects enable the comparison of relative efficiencies among hospitals after adjustment for patient case-mix and health provision characteristics.

Adult↗