Biomedical subjects

Y Ye

Publications and source records attributed to Y Ye.

At least 19 recordsLinked to original sources

PubMed2006

Enterobacter bacteremia: Clinical features, risk factors for multiresistance and mortality in a Chinese University Hospital.

BACKGROUND: This study was performed to characterize the clinical features and to identify the risk factors for multiresistance and mortality in patients with Enterobacter bacteremia. PATIENTS AND METHODS: A number of 126 patients with Enterobacter bacteremia in 1995-2004 at the Medical university-affiliated Hospital of Anhui, China were retrospectively analyzed. RESULTS: Of the 126 cases of bacteremia, 81 (64.3%) patients were identified as nosocomial infection. The overall multiresistance rate was 45.2% (57/126). Multiresistance was associated with nosocomial infection, recent invasive procedure, previous third-generation cephalosporins therapy, prolonged perioperative prophylaxis, the species of Enterobacter (E. cloacae) and polymicrobial bacteremia in univariate analysis. In multivariate analysis, previous third-generation cephalosporins therapy (OR = 13.6, p = 0.007) and prolonged perioperative prophylaxis (OR = 6.4, p = 0.029) were the strong, independent risk factors for the multiresistance. The crude 30-day mortality rate was 39.7% (50/126). Mortality directly attributed to Enterobacter spp. was 32.5% (41/126), which was significantly associated with multiresistance, nosocomial infection, recent invasive procedure, and inadequately empirical therapy in univariate analysis. Multivariate analysis revealed that only nosocomial infection (OR = 3.292, p = 0.049) was independently associated with mortality. The survival curve showed that the inappropriate initial therapy group had a lower probability of survival than the appropriate therapy group in infection-related mortality (Log Rank, p = 0.0142). CONCLUSION: Enterobacter is becoming increasingly important nosocomial pathogens. Nosocomial infection is a clinical risk factor tightly associated with multiresistance and worse outcome. More judicious use of third-generation cephalosporins may decrease the incidence of nosocomial multiresistant Enterobacter spp. in China.

Adolescent↗

PubMed2006

p53, Apaf-1, caspase-3, and -9 are dispensable for Cdk5 activation during cell death.

Cyclin-dependent kinase 5 (Cdk5) is a member of the cyclin-dependent kinase family that is mostly seen in neurons, does not vary with cell cycle, and is activated in many neurodegenerative disorders and other non-neuronal pathologies, but its relationship to non-neuronal apoptosis is not understood, nor is the control of the activation of Cdk5 by its activators. The most widely studied activator of Cdk5, p35, is cleaved to p25 by calpain, an event that has been linked with activation of Cdk5 and neuronal death. Here we report that calpain-mediated Cdk5/p25 activation accompanies non-neuronal as well as neuronal cell death, suggesting that the p35/calpain/p25/Cdk5 activation sequence is a general feature of cell death. We further demonstrate that Cdk5 can be activated in the absence of p53, Apaf-1, caspase-9, and -3 during cell death, indicating that its activation relates more to cell death than to a specific pathway of apoptosis.

Animals↗

PubMed2006

Labdane diterpenes from the seeds of Platycladus orientalis.

Two new labdane diterpenes, 14(R),15-dihydroxy-8(17),12(E)-labdadien-19-oic acid (1) and 16-methyl-12,15-epoxy-8(17),13-labdadien-19-oic acid (2), together with four known compounds, were isolated from the seeds of Platycladus orientalis. Their structures were established by spectroscopic methods. The stereochemistry of compound 1 was defined by X-ray crystallographic analysis.

China↗

PubMed2005

Calculation and usage of containment monitor radiation readings during PWR accidents.

A computer code named CALCON for calculation of containment monitor radiation readings is introduced. The validity of the code was verified by comparison with data given in IAEA technical documents. The contribution of isotopes to containment readings under conditions of core melt, gap release and normal coolant release were investigated. The conclusions were that the radiation reading in containment is mainly from iodine and noble gases when sprays are off, and the radiation reading is mainly from noble gases when sprays are on, and during the beginning hours when radionuclides are released into containment, the monitor readings will decrease rapidly. Curves of containment radiation readings versus shutdown time for DAYA BAY nuclear power plant were calculated using CALCON.

Radiation Dosage↗

PubMed2005

Clinical assessment compared with breathalyser readings in the emergency room: concordance of ICD-10 Y90 and Y91 codes.

OBJECTIVES: The purpose of this study was to analyse the validity of clinical assessment of alcohol intoxication (ICD-10 Y91) compared with estimated blood alcohol concentration (BAC) using a breath analyser (ICD-10 Y90) among patients in the emergency room (ER). METHODS: Representative samples of ER patients reporting within six hours of injury (n = 4798) from 12 countries comprising the WHO Collaborative Study on Alcohol and Injuries were breath analysed and assessed blindly for alcohol intoxication at the time of ER admission. Data were analysed using Kendall's Tau-B to measure concordance of clinical assessment and BAC, and meta analysis to determine heterogeneity of effect size. RESULTS: Raw agreement between the two measures was 86% (Tau-B 0.68), but was lower among those reporting drinking in the six hours prior to injury (raw agreement 39%; Tau-B 0.32). No difference was found by gender or for timing of clinical assessment in relation to breath analysis. Patients positive for tolerance or dependence were more likely to be assessed as intoxicated at low levels of BAC. Estimates were homogeneous across countries only for females and for those negative for alcohol dependence. CONCLUSIONS: Clinical assessment is moderately concordant with level of BAC, but in those patients who have actually been drinking within the last six hours the concordance was much less, possibly because, in part, of a tendency on the part of clinicians to assign some level of intoxication to anyone who appeared to have been drinking.

Alcohol Drinking↗

PubMed2003

A subpopulation of dorsal raphe nucleus neurons retrogradely labeled with cholera toxin-B injected into the inner ear.

Previous studies have shown that: (1) raphe neurons respond to acoustic and vestibular stimuli, some with a latency of 10-15 ms; (2) alterations of the raphe nuclei alter the acoustic startle reflex; (3) the dorsal raphe nucleus (DRN) is the major source of serotonergic neurons; and (4) approximately 57% of the DRN neurons are nonserotonergic. In the present study, cholera toxin subunit-B (CTB) was injected into cat cochleas, and the brain tissue was examined after a survival period of 5-7 days. Aside from neurons which were known to project to the inner ear, i.e., olivocochlear and vestibular efferent neurons, a surprising new finding was made that somata of a subpopulation of DRN neurons were intensely labeled with CTB. These CTB-labeled neurons were densely distributed in a dorsomedian part of the DRN with some in a surrounding area outside the DRN. The present results suggest that a novel raphe-labyrinthine projection may exist. A future study of anterograde labeling with injections of a tracer in the DRN will be needed to establish the existence of a raphe-labyrinthine projection more thoroughly. A raphe-labyrinthine descending input, together with an ascending input from the inner ear to the DRN through intervening neurons, such as the juxta-acousticofloccular raphe neurons (JAFRNs) described by Ye and Kim, may mediate a brain stem reflex whereby a salient multisensory (including auditory and vestibular) stimulus may alter the sensitivity of the inner ear. As a mammal responds to a biologically important auditory-vestibular multisensory event, the raphe projections to the inner ear and other auditory and vestibular structures may enhance the mammal's ability to localize and recognize the sound and respond properly. The raphe-labyrinthine projection may also modulate the inner ear's sensitivity as a function of the sleep-wake arousal state of an organism on a slower time course.

Animals↗

PubMed2003

Fourier-transform Raman and infrared spectroscopic analysis of 2-nitro-tetraphenylporphyrin and metallo-2-nitro-tetraphenylporphyrins.

The Fourier-transform Raman (FT-Raman) and infrared (FT-IR) spectra of 2-nitro-tetraphenylporphyrin (2-NO(2)-TPP), nickel-2-nitro-tetraphenylporphyrin (Ni-2-NO(2)-TPP), zinc-2-nitro-tetraphenylporphyrin (Zn-2-NO(2)-TPP) and copper-2-nitro-tetraphenylporphyrin (Cu-2-NO(2)-TPP) were acquired for the first time and carefully assigned and discussed. The effects of a beta-NO(2) group and the influence of the central metal on the molecular symmetry and vibrational spectra of the porphyrin macrocycle were also examined. The bands at 1323-1339, 1516-1526 and 961-971 cm(-1) were attributed to the symmetric and asymmetric stretching vibration of the NO(2) group and to the stretching vibration of the C(beta)-N bond, respectively, which connects the NO(2) group with the beta-carbon of the porphyrin macrocycle. These bands can act as a marker to distinguish beta-NO(2) TPPs from other beta-substituent TPPs. Cu-2-NO(2)-TPP has a C(4nu) molecular symmetry, which is different from those of Ni-2-NO(2)-TPP and Zn-2-NO(2)-TPP, i.e. D(4h).

Organometallic Compounds↗

PubMed2002

Transduction of human neural progenitor cells using recombinant adeno-associated viral vectors.

Human neural progenitor cells (hNPCs) represent an attractive source for cell therapy of neurological disorders. Genetic modification of hNPCs may allow a controlled release of therapeutic proteins, suppress immune rejection, or produce essential neurotransmitters. In search of an effective gene delivery vehicle, we evaluated the efficiency of a recombinant adeno-associated viral (rAAV) vector expressing enhanced green fluorescent protein (CAGegfp). Our study demonstrated that CAGegfp efficiently transduced both proliferating and differentiated hNPCs in vitro. EGFP expression was detected as early as 1 day after exposure to CAGegfp and was detectable for up to 4 months. Following transduction, the growth rate of hNPCs slowed down, but they were still able to differentiate into neurons and glia. Furthermore, CAGegfp-modified hNPCs survived, differentiated and expressed EGFP after transplanting into spinal cord of adult rats. Our results indicated that rAAV vectors might be a useful tool in hNPC-based cell and gene therapy for neurological disorders.

Adenoviridae↗

PubMed2001

The AAA ATPase Cdc48/p97 and its partners transport proteins from the ER into the cytosol.

In eukaryotic cells, incorrectly folded proteins in the endoplasmic reticulum (ER) are exported into the cytosol and degraded by the proteasome. This pathway is co-opted by some viruses. For example, the US11 protein of the human cytomegalovirus targets the major histocompatibility complex class I heavy chain for cytosolic degradation. How proteins are extracted from the ER membrane is unknown. In bacteria and mitochondria, members of the AAA ATPase family are involved in extracting and degrading membrane proteins. Here we demonstrate that another member of this family, Cdc48 in yeast and p97 in mammals, is required for the export of ER proteins into the cytosol. Whereas Cdc48/p97 was previously known to function in a complex with the cofactor p47 (ref. 5) in membrane fusion, we demonstrate that its role in ER protein export requires the interacting partners Ufd1 and Npl4. The AAA ATPase interacts with substrates at the ER membrane and is needed to release them as polyubiquitinated species into the cytosol. We propose that the Cdc48/p97-Ufd1-Npl4 complex extracts proteins from the ER membrane for cytosolic degradation.

Adaptor Proteins, Vesicular Transport↗

PubMed2001

A novel growth suppressor gene on chromosome 17p13.3 with a high frequency of mutation in human hepatocellular carcinoma.

Previous studies have shown that there is a high frequency of loss of heterozygosity (LOH) on chromosome 17p13.3 in hepatocellular carcinoma [HCC (M. Fujimori et al., Cancer Res., 51: 89-93, 1991; H. Nagai et al., Oncogene, 14: 2927-2933, 1997; V. Boige et al., Cancer Res., 57: 1986-1990, 1997; Z. Piao et al., Int. J. Cancer, 75: 29-33, 1998; and B. Charroux et al., J. Cell Biol., 148: 1177-1186, 2000)]. The minimum region of LOH on chromosome 17p13.3 in HCC has been defined within the region between D17S643 and D17S1574. Moreover, D17S926 in the minimum region of LOH has the highest frequency of LOH, and its sequencing analysis has been accomplished. In this region, 6 of 13 novel genes have been characterized (X. Zhao, D. Wan, M. He, Yu. Ye, Yi. He, L. Han, M. Guo, Y. Huang, W. Qin, M-W. Wang, W. Chong, J. Chen, L. Zhang, N. Yang, B. Xu, M. Wu, L. Zuo, and J. Gu. A high frequency LOH region on chromosome 17p13.3 in human HCC with densely clustered genes identified, submitted for publication). Here we describe the cloning and characterization of one of these novel genes, designated HCC suppressor 1 (HCCS1), located at this region. HCCS1 had 18 exons, and its full-length cDNA was 2.0 kb. The protein expression product of HCCS1 was located in mitochondria. HCCS1 had a high frequency of mutations in HCC samples, whereas no alteration has been found in matched noncancerous liver tissues. Immunohistochemistry revealed a significantly higher expression of HCCS1 in the noncancerous liver tissues (33 of 35 samples) than in the HCC samples (2 of 35 samples). Transfection of HCCS1 cDNA into the HCC cell line remarkably reduced the efficiency of its colony formation and inhibited tumor growth in nude mice. Taken together, these findings strongly suggest a potential role of HCCS1 as a HCC putative suppressor gene.

3T3 Cells↗

PubMed2001

Development of rolipram-sensitive, cyclic AMP phosphodiesterase (PDE4) in rat primary neuronal cultures.

The development of PDE4 was examined in primary neuronal cultures of rat cerebral cortex. Three days after culturing, neurons exhibited relatively low PDE4 activity (i.e., rolipram-sensitive PDE activity). It gradually increased over time, approximately doubling by day 12. The increase in activity was accompanied by an increase in the expression of the PDE4A variants, PDE4A5 and PDE4A1, as well as of the synaptic marker protein synapsin I. There was a strong correlation between the expression of the PDE4A variants with that of synapsin I, which suggests that as neurons develop and signal transduction increases there is a regulated increase in PDE4 expression and activity. Consistent with this interpretation, it was found that treatment with the sodium channel blocker tetrodotoxin, which inhibits depolarization-induced neurotransmitter release, reduced the expression of the PDE4A variants. These data demonstrate the developmental regulation of PDE4 in neurons and offer a manner by which the association of PDE4 variants with particular signal transduction pathways may be studied in vitro.

3',5'-Cyclic-AMP Phosphodiesterases↗

PubMed2001

Parathyroid hormone-related protein overexpression in the human colon cancer cell line HT-29 enhances adhesion of the cells to collagen type I.

The present experiments examined the potential ability of parathyroid hormone-related protein (PTHrP) to influence growth of the human colon cancer cell HT-29 and the ability of the cell to adhere to several extracellular matrix (ECM) proteins found in normal tissues. Addition of PTHrP analogs, PTHrP (1-34), PTHrP (67-86), or PTHrP (107-139), to HT-29 cells in culture did not influence cell growth or the adhesion of the cells to wells coated with fibronectin, laminin, or collagen type I. Likewise, in HT-29 cells induced to overexpress PTHrP by stable transfection with PTHrP cDNA, compared to vector-transfected control HT-29 cells, no effect on cell growth occurred. However, in the transfected cells, the increased production of PTHrP significantly enhanced cell adhesion to type I collagen but not to fibronectin or laminin. The results raise the possibility that PTHrP might play a role in colon tumor invasion and metastasis by influencing cell adhesion to specific extracellular matrix proteins.

Cell Adhesion↗

PubMed2001

[Protective effect of ginsenosides on human peritoneal mesothelial cell against lactate-based peritoneal dialysis solutions--induced injury in vitro].

OBJECTIVE: The aim of this research was to observe the influence of ginsenosides (GS) on viability and proliferation of human peritoneal mesothelial cell (HPMC) which were inhibited by L-PDS in vitro. METHOD: Mesothelial cells were isolated from human omental specimens by trypsin disaggregation and established a stable HPMC culture model. The viability and capacity of proliferation of HPMC were assessed by lactate dehydrognase (LDH) release and tetrazolium salt colorimetry assay (MTT assay). RESULTS: Compared with the control group, the release of LDH in L-PDS groups (2.5%, 4.25% glucose) significantly increased. But there was no difference between the two glucose concentrations. As HPMC pre-exposed to L-PDS prolonged, the viability of cells decreased gradually. GS decreased the release of LDH and increased the cells viability (P < 0.01), as well as enhanced the proliferation of HPMC. CONCLUSION: The results suggest that GS has some protective effects on cell viability and proliferation of HPMC inhibited by L-PDS in vitro.

Cell Division↗

PubMed2001

Effect of zinc supplementation on malaria and other causes of morbidity in west African children: randomised double blind placebo controlled trial.

OBJECTIVE: To study the effects of zinc supplementation on malaria and other causes of morbidity in young children living in an area holoendemic for malaria in west Africa. DESIGN: Randomised, double blind, placebo controlled efficacy trial. SETTING: 18 villages in rural northwestern Burkina Faso. PARTICIPANTS: 709 children were enrolled; 685 completed the trial. INTERVENTION: Supplementation with zinc (12.5 mg zinc sulphate) or placebo daily for six days a week for six months. MAIN OUTCOME MEASURES: The primary outcome was the incidence of symptomatic falciparum malaria. Secondary outcomes were the severity of malaria episodes, prevalence of malaria parasite, mean parasite densities, mean packed cell volume, prevalence of other morbidity, and all cause mortality. RESULTS: The mean number of malaria episodes per child (defined as a temperature >/=37.5 degrees C with >/=5000 parasites/microliter) was 1.7, 99.7% due to infection with Plasmodium falciparum. No difference was found between the zinc and placebo groups in the incidence of falciparum malaria (relative risk 0.98, 95% confidence interval 0.86 to 1.11), mean temperature, and mean parasite densities during malaria episodes, nor in malaria parasite rates, mean parasite densities, and mean packed cell volume during cross sectional surveys. Zinc supplementation was significantly associated with a reduced prevalence of diarrhoea (0.87, 0.79 to 0.95). All cause mortality was non-significantly lower in children given zinc compared with those given placebo (5 v 12, P=0.1). CONCLUSIONS: Zinc supplementation has no effect on morbidity from falciparum malaria in children in rural west Africa, but it does reduce morbidity associated with diarrhoea.

Diarrhea↗

PubMed2001

Overexpression of parathyroid hormone-related protein promotes cell growth in the rat intestinal cell line IEC-6.

The rat intestinal cell line, IEC-6, was used as a model to study effects of parathyroid hormone-related protein (PTHrP) on crypt cell growth. Studies showed that addition of PTHrP analogs (1-34), (67-86), or (107-139) to growth medium did not affect proliferation of cells grown in either high (10% Nu-Serum) or low serum (1% Nu-Serum). However, studies on clonal lines of IEC-6 cells stably transfected with PTHrP cDNA and overexpressing PTHrP showed that increased PTHrP production enhanced cell growth and 3H-thymidine incorporation in high, but not low, serum. Additional studies examined the role of the nuclear localization sequence (NLS) of PTHrP in mediating the growth effect. In three clonal IEC-6 lines transfected with PTHrP cDNA bearing a mutated NLS, the ability of PTHrP to stimulate 3H-thymidine incorporation and cell growth was lost. The results suggest that endogenously produced PTHrP can promote proliferation of IEC-6 cells and that the integrity of the NLS of PTHrP is required for its growth effects.

Animals↗

PubMed2001

[Keratin 17 gene mutation in patients with steatocystoma multiplex].

OBJECTIVE: To study the relationship between steatocystoma multiplex (SCM) and keratin 17 gene mutation. METHODS: The keratin 17 gene mutation in the cDNA of cystic tissue of 5 patients of SCM and in the DNA in peripheral blood of 25 patients with SCM from a SCM family was studied by direct sequencing of the RT-PCR products, nested PCR, and restricted fraction length polymorphism (RFLP) analysis. Thirty-nine blood specimens from the unaffected members of that family were collected and tested too. Ten DNA pool specimens and other 2000 DNA pool specimens of normal individuals outside that SCM family were used as controls. RESULTS: In the base 428, 94(th) codon in keratin 17 gene in the cDNA of patients' cystic tissue, R94C mutation, a G-->A mutation, was detected Nested PCR, and restricted enzyme Acil polymorphism analysis showed that in the DNA specimens of peripheral blood of patients a mutated allele lacking enzyme cutting locus was detected, thus causing an uncut band with 200 bp while the corresponding allele was cut and caused two bands with 108 bp and 92 bp. In the DNA pool specimens of normal controls only these two bands with 108 bp and 92 bp were observed. CONCLUSION: The R94C mutation in keratin 17 gene is one of the genetic bases of SCM in Chinese. The results of this study provide scientific data for genetic diagnosis and counseling of SCM.

Adolescent↗

PubMed2001

Oropharyngeal candidiasis in patients with human immunodeficiency virus: correlation of clinical outcome with in vitro resistance, serum azole levels, and immunosuppression.

Azole-resistant thrush has emerged as a problem in people who are infected with human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS), especially those who have low CD4 cell counts who have had a previous relapse of oral candidiasis, and in those who require long-term suppressive antifungal therapy. Because of the development of a standardized methodology for antifungal susceptibility testing and interpretive criteria for resistance testing, studies of the clinical predictive value of in vitro results are possible. In this study, 61% of organisms isolated from patients who were receiving azole therapy and who had clinically resistant thrush had minimal inhibitory concentration values that would classify the isolate as "resistant" or "susceptible dose dependent." In contrast, 86% of isolates from patients with thrush that was clinically responsive to an azole were classified in vitro as "susceptible" or "susceptible dose dependent." No resistant isolates were detected in samples obtained from asymptomatic control patients who were not exposed to azole drugs. Serum levels of azole and CD4 cell counts were also important parameters with regard to prediction of response. We conclude that in vivo and in vitro correlations compare favorably to studies of susceptibility testing in bacteria.

AIDS-Related Opportunistic Infections↗

PubMed2001

High-energy phosphate metabolism and creatine kinase in failing hearts: a new porcine model.

BACKGROUND: This study aimed to create a pig model of heart failure secondary to severe aortic stenosis and to examine the relationship between the alterations in myocardial high-energy phosphate (HEP) metabolism and protein expression of creatine kinase (CK) isoforms. METHODS AND RESULTS: Sixteen pigs with left ventricular hypertrophy (LVH) secondary to ascending aortic banding and 10 normal pigs (N) were studied. Myocardial protein levels of CK isoforms (Western blot), HEP levels, and CK kinetics ((31)P MR spectroscopy) were measured under basal conditions. Nine of the 16 animals with LVH developed congestive heart failure (CHF), as evidenced by ascites (100 to 2000 mL). LV weight/body weight ratio (g/kg) was 2.18+/-0.15 in N hearts, 3.04+/-0.14 in hearts with LVH (P<0.01), and 4.23+/-0.36 in hearts with CHF (P<0.01 versus LVH). Right ventricle weight/body weight ratio and LV end-diastolic pressure were significantly higher in hearts with CHF (each P<0.01 versus N or LVH). Myocardial phosphocreatine/ATP ratios and the CK forward flux rates were decreased in LVH hearts, most severely in hearts with CHF. CK-M/beta-actin ratios were 2.21+/-12 (N), 1.69+/-0.15 (LVH), and 1.39+/-0.27 (CHF, P<0.05 versus N). CK-mitochondria (CK-Mt)/beta-actin ratios were 1.40+/-0.09 (N), 1.24+/-0.09 (LVH), and 1.02+/-0.08 (CHF, P<0.05 versus N or LVH). The severity of the reduction of CK flux rate was linearly related to the severity of the decrease of CK-Mt/beta-actin (r=0.68, P<0.01). CONCLUSIONS: In this new model of heart failure/hypertrophy, the abnormal myocardial HEP metabolism is related to the decreased CK-Mt protein level, which in turn is related to the severity of the hypertrophy.

Adenosine Triphosphate↗