Biomedical subjects

Y Yang

Publications and source records attributed to Y Yang.

At least 127 records · Page 7Linked to original sources

PubMed2002

Detection of antivimentin antibody in sera of patients with idiopathic pulmonary fibrosis and non-specific interstitial pneumonia.

It has been suggested that the humoral immune system plays a role in the pathogenesis of non-specific interstitial pneumonia (NSIP). Although some circulating autoantibodies to cytoskeletal protein(s) have been suggested, the antimyofibroblast antibody has not been investigated in patients with idiopathic pulmonary fibrosis (IPF) and NSIP. The purpose of this study is to evaluate the existence of antimyofibroblast antibody in the sera of patients with IPF and NSIP. The MRC5 cell line was used as a model of myofibroblast. The anti-MRC5 cell antibody was characterized in a patient with NSIP using Western blotting. Since we found that one of the anti-MRC5 antibodies was an antivimentin antibody, we established an enzyme-linked immunosorbent assay (ELISA) to measure the levels of antivimentin antibody in the sera of patients with IPF (n = 12) and NSIP (n = 23). Initially, two anti-MRC5 cell antibodies were detected in the sera of patients with NSIP, one of which was characterized as the antivimentin antibody by Western blotting. The other was characterized as an antivimentin fragment antibody. We established an ELISA to measure the antivimentin antibody and found significantly higher levels in patients with IPF and NSIP than in normal volunteers. One of the anti-MRC5 cell antibodies in the serum of a patient with NSIP was against vimentin. The serum levels of antivimentin antibody were increased in patients with IPF and NSIP compared with that of normal volunteers. These results suggest that the antivimentin antibody may be involved in the process of lung injury in IPF and NSIP.

Autoantibodies↗

PubMed2002

Structure-antiemetic-activity of some diarylheptanoids and their analogues.

The structure-activity relationship of diarylheptanoids and their analogues inhibitory of emesis induced by copper sulfate in young chicks was investigated by testing 19 compounds. The compounds are 5 diarylheptanoids isolated from Alpinia katsumadai (Zingiberacea), 5 chemical derivatives of them, 6 analogues isolated from Zingiber officinale rhizome (Zingiberaceae), and 3 analogues available on the market. Among them, two types of essential functional structure of diarylheptanoids and their analogues showed the inhibitory effects against emesis.

Animals↗

PubMed2002

Understanding of hazardous waste incineration through computational fluid-dynamics simulation.

Rotary kiln incinerators are widely used in the incineration of hazardous wastes of various types. However, the complex transport and chemical processes within the kiln system are still not well understood. The complete destruction of hazardous compounds depends very much on gas mixing behavior of different air and waste streams, the distribution of gas temperature and residence time within the kiln and the secondary combustion chamber (SCC). Due to large variations of waste types and difficulties in feed characterization (physical, chemical and thermal properties), the incineration process meets great challenges in a smooth operation, with substantial fluctuations of gas temperatures within the system. The temperature fluctuations lead to uncertainties in the process chemistry and difficulties in emission control. The newly enforced regulations from the European Union with stricter emission levels require a better understanding of the incineration process and improved process control for lower emissions and a better environmental impact. In order to get better understanding of the incineration process within the rotary kiln system, research was carried out to study the kiln behavior in relation to better process control. One of the focuses was on the process simulation by using Computational Fluid-dynamics (CFD) to characterize gas flow, temperature distribution and waste combustion in the rotary kiln incinerator. Temperature measurement of the operating rotary kiln incinerator at AVR-Chemie, located at the Rotterdam harbor in The Netherlands, was conducted to validate the CFD model and to provide the information to kiln operators at AVR. This paper will address the environmental issues related to the hazardous waste incineration, and summarize the results from the current research project for the simulation of gas flow and mixing, combustion heat transfer, and new ideas to use CFD simulation results for process control of an incineration plant.

Air Movements↗

PubMed2002

Is there an increased rate of additional malignancies in patients with mantle cell lymphoma?

PURPOSE: To examine the frequency of additional neoplasms preceding and following the diagnosis of mantle cell lymphoma (MCL). PATIENTS AND METHODS: A total of 156 patients with MCL treated on the hyperfractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone alternated with methotrexate and cytosine arabinoside (Hyper-CVAD/M-A) program with or without rituximab from 1994 to 2000 were the subjects of this report. RESULTS: These patients were followed for a median time of 26 months, and a total of 32 (21%) additional neoplasms were diagnosed, 21 preceding the diagnosis of MCL and 11 following MCL. After excluding certain types of non-invasive neoplasms, including basal cell carcinoma, meningioma and cervical intraepithelial neoplasia, we observed seven second malignancies after the diagnosis of MCL, and the 5-year cumulative incidence rate of second malignancy was 11%. The observed-to-expected (O/E) ratio was 7/0.07 = 100 [95% confidence interval (CI) 49.3 to 186.6; P <0.0001]. Of the 21 malignancies diagnosed prior to MCL, 16 were invasive and five non-invasive. There were a total of 10 urologic malignancies occurring before or after the diagnosis of MCL was established. CONCLUSIONS: Our findings suggest that there is an increased incidence of second malignancies in patients with MCL. In addition, the high number of cases with urinary tract cancer in our series may substantiate prior reports describing a possible association between lymphoma and urologic malignancies.

Adult↗

PubMed2002

Self perceived work related stress and the relation with salivary IgA and lysozyme among emergency department nurses.

AIMS: To assess and compare the self perceived work related stress among emergency department (ED) and general ward (GW) nurses, and to investigate its relation with salivary IgA and lysozyme. METHODS: One hundred and thirty two of 208 (63.5%) registered female ED and GW nurses participated in the study. A modified mental health professional stress scale (PSS) was used to measure self perceived stress. ELISA methods were used to determine the salivary IgA and lysozyme levels. RESULTS: On PSS, ED nurses had higher scores (mean 1.51) than GW nurses (1.30). The scores of PSS subscales such as organisational structure and processes (OS), lack of resources (RES), and conflict with other professionals (COF) were higher in ED than in GW nurses. ED nurses had lower secretion rates of IgA (geometric mean (GM) 49.1 micro g/min) and lysozyme (GM 20.0 micro g/min) than GW nurses (68.2 micro g/min, 30.5 micro g/min). Significant correlations were observed between PSS and log IgA and lysozyme secretion rates. OS, RES, and COF were correlated with log IgA and lysozyme levels. CONCLUSION: ED nurses, who reported a higher level of professional stress, showed significantly lower secretion rates of salivary IgA and lysozyme compared to GW nurses. Salivary IgA and lysozyme were inversely correlated with self perceived work related stress. As these salivary biomarkers are reflective of the mucosal immunity, results support the inverse relation between stress and mucosal immunity.

Adult↗

PubMed2002

Healing venous ulcers with cycloidal multidirectional vibration therapy.

OBJECTIVE: This preliminary study combined compression bandaging with cycloidal vibration to determine whether this would enhance the rate of healing of venous leg ulceration. METHOD: Twenty-one patients with venous ulceration were enrolled into a 12-week trial. The vibration device was used three times daily for 30 minutes on each occasion, along with compression bandaging. RESULTS: Ulcers of 13 patients (62%) healed within 12 weeks. The remaining eight patients completed the 12-week study with a 31-90% reduction in ulcer size. A reduction in pain was observed in 17 out of 21 patients (81%). Ultrasound measurements showed reduced fluid content in the upper dermis in patients whose ulcers had healed and in others whose ulcers were improving. CONCLUSION: This preliminary study shows that gentle cycloid vibration, combined with standard compression bandaging, enhances the healing rate of venous ulcers and helps to relieve pain.

Aged↗

PubMed2002

Effect of Traumacel P on the growth of human dermal fibroblasts in vitro.

OBJECTIVE: It has been postulated that Traumacel P, a haemostatic powder, might assist the wound-healing process. This in vitro study investigated the effect of the powder on human dermal fibroblasts. METHOD: Experiments using fibroblasts from a 50-year-old donor were carried out using suspensions of Traumacel P ranging from 0.1 to 10.0 mg/ml. Dulbecco's Modified Eagle Medium with 10% or 0.4% foetal calf serum (FCS) and 5.5 mM or 25 mM glucose was used. The powder was either placed in contact with the cells or separated from them by a porous membrane. The response of the fibroblasts was assessed using the MTT assay. RESULTS: Concentrations of 0.5 mg/ml and 1.0 mg/ml stimulated the metabolic activity of the fibroblasts in both high and low glucose medium with 10% FCS, regardless of whether the powder was in contact with or separated from the cells. The greatest stimulation, to 174% of the controls, was produced by 0.5 mg/ml Traumacel P in low glucose/10% FCS with the powder in contact with the cells (p < 0.0001). Traumacel concentrations ranging from 0.5 to 5.0 mg/ml in 0.4% FCS significantly stimulated the metabolic activity of fibroblasts in low glucose medium, but not in the high glucose medium. CONCLUSION: These studies indicate that direct stimulation of fibroblast proliferation may be one of the ways in which Traumacel P aids the healing of ulcers observed in the clinic.

Cells, Cultured↗

PubMed2002

The effects of antisense insulin-like growth factor-I receptor oligonucleotide on human cord blood lymphocytes.

Our objective was to study the effects of type I insulin-like growth factor receptor (IGF-IR) on human cord blood lymphocyte (CBL) functions. First, we used RT-PCR to determine the expression of IGF-IR at the mRNA level in CBL. We then inhibited the expression of IGF-IR in CBL by the antisense oligonucleotide for the IGF-IR gene. We measured the changes in interleukin (IL)-2, -4 and interferon-gamma (IFN gamma) at mRNA levels by RT-PCR, immunoglobulin M (IgM) production by CBL with an ELISA and lymphocyte proliferation by a (3)H-thymidine uptake technique. Our results showed that IGF-IR mRNA was detected in both non-activated and activated CBL, but the expression levels in the activated CBL were higher than those in the non-activated CBL. After being exposed to the antisense oligonucleotide, a 50% reduction in the amount of IGF-IR mRNA occurred. Accordingly, the proliferation of CBL to mitogen was significantly reduced about 50%, and the production of IgM from CBL was also markedly decreased. In the phytohemagglutinin-stimulated CBL culture system, when the IGF-IR antisense oligonucleotide existed, the mRNA levels of IFN gamma and IL-2 decreased 30-50% and IL-4 decreased 20-30%. We concluded that IGF-IR is most likely involved in the process of CBL proliferation and production of immunoglobulin and cytokines. It might therefore play an important role in the modulation of the immune functions.

Base Sequence↗

PubMed2002

Oilfield produced water treatment with surface-modified fiber ball media filtration.

In order to explore the PET fiber's potential as a filter medium to treat the water produced from oil production, modification technology was adopted to modify the fiber surface. After modification, the PET fiber surface was grafted by the -COOH, =NH and -OH groups. Therefore, the property of the modified fiber changed from oleophilic to hydrophilic, which makes the fiber easy to backwash. Water produced from atypical oil field in the north of China was treated on site with filter filled with this new fiber medium. The results are compared with the results from a filter filled with currently popular walnut medium, where the experiment conditions are the same as that of the fiber filter. When the velocity is lower than 15 m/h, the effluent from fiber filter can control the oil concentration < 2.4 mg/l, SS < 2.0 mg/l, and D50 < 2 microm, which meets the requirements for waterflood (water injection) into the ground. But the walnut medium filter can only control the oil concentration < 5 mg/l, TSS < 2.0 mg/l, and failed to control the d50 < 2 microm, which is the crucial deficiency of the walnut medium. The fiber medium still shows a great ability to control particles even with higher filtration velocity and worse influent. With a filtration velocity of 20 m/h and 36.4 microm d50 of influent, the d50 of the fiber filter effluent is 3.302 microm, but that of walnut filter is 10.74 microm. The reason for this is due to the compressibiliy of the fiber medium while the walnut median is incompressible. Recommendations for future studies on pilot-scale experiments to improve backwash and to determine operational parameters are presented.

Filtration↗

PubMed2001

[Efficacy and safety of low dose amiodarone for paroxysmal atrial fibrillation in the aged patients with no-valvular heart diseases].

OBJECTIVE: To study the efficacy and safety of low-dose amiodarone (AD) for paroxysmal atrial fibrillation in the aged patients with no-valvular heart diseases. METHOD: 40 inpatients were treated with load-dose AD (600 mg.d-1) for 6 days and then low maintenance dose of 50 mg or 100 mg daily. Clinical efficacy was evaluated with 24 h dynamic electrocardiogram. RESULTS: AD maintained efficaciously sinus rhythm about 90.0% (36/40) during 6 months, about 83.3% (25/30) during 12 months, about 72.7% (16/22) during 24 months. Only 2 patients were stopped oral AD because sinus bradycardia(< or = 45 bpm) occurred. CONCLUSION: Low dose AD (50-100 mg.d-1) is a safe and efficient maintenance of sinus rhythm in aged patients with no-valvular heart diseases and paroxysmal atrial fibrillation.

Aged↗

PubMed2001

Ex vivo priming for long-term maintenance of antileukemia human cytotoxic T cells suggests a general procedure for adoptive immunotherapy.

Adoptive cellular immunotherapy has proven to be a successful approach in preventing and curing cytomegalovirus infection and Epstein-Barr virus-associated lymphomas after bone marrow transplantation. Translation of this approach for preventing leukemia relapse after bone marrow transplantation might require ex vivo priming and long-term maintenance of leukemia blast-specific T cells. To accomplish this goal, procedures were optimized for the in vitro priming of naive CD8 using dendritic cells activated by CD40 ligation, interleukin-12 (IL-12), and IL-7. Using T lymphocytes and dendritic cells obtained from HLA-matched allogeneic bone marrow transplantation donors and leukemia blasts as a source of tumor antigens, anti-acute myeloid leukemia cytotoxic T lymphocytes (CTLs) were induced. In these experiments, it was found that though it is possible to induce CTLs using immature dendritic cells, IL-12, and IL-7, obtaining long-term CTLs requires the presence of CD4 T cells in the priming phase. Using this approach, long-term antileukemia CTL lines could be generated from 4 of 4 bone marrow donors. Because this procedure does not require definition of the target antigen and because it selects responding cells from a virgin T-cell repertoire, its general application is suggested in adoptive immunotherapy and in the definition of tumor rejection antigens.

Bone Marrow Transplantation↗

PubMed2001

Targeted disruption of the murine Fanconi anemia gene, Fancg/Xrcc9.

Fanconi anemia (FA) is a human autosomal recessive cancer susceptibility disorder characterized by cellular sensitivity to mitomycin C and ionizing radiation. Six FA genes (corresponding to subtypes A, C, D2, E, F, and G) have been cloned, and the encoded FA proteins interact in a common cellular pathway. To further understand the in vivo role of one of these human genes (FANCG), we generated a targeted disruption of murine Fancg and bred mice homozygous for the targeted allele. Similar to the phenotype of the previously described Fancc(-/-) and Fanca(-/-) mice, the Fancg(-/-) mice had normal viability and no gross developmental abnormalities. Primary splenic lymphocytes, bone marrow progenitor cells, and murine embryo fibroblasts from the Fancg(-/-) mice demonstrated spontaneous chromosome breakage and increased sensitivity to mitomycin C and, to a lesser extent, ionizing radiation. Fancg(-/-) lymphocytes had a defect in the FA pathway, based on their failure to activate the monoubiquitination of the downstream Fancd2 protein in response to IR. Finally, Fancg(-/-) mice had decreased fertility and abnormal gonadal histology. In conclusion, disruption of the Fancg gene confirms the role of Fancg in the FA pathway. The Fancg(-/-) mouse may be useful as an animal model for future gene therapy and cancer susceptibility studies.

Alleles↗

PubMed2001

[Human GDNF cDNA-engineered SH-SY5Y cells' neurotrophic and protective effect on primary dopaminergic neurons of rat].

OBJECTIVE: To construct a kind of engineered cell secreting human GDNF and study its possible effects on gene therapy of Parkinson's disease. METHOD: Human GDNF cDNA with Kozak sequence was cloned by RT-PCR, and then was transfected into SH-SY5Y cell line of human neuroblastoma. These engineered cells were co-cultured with primary mesencephalic cells of rats. Dopaminergic neurons were examined by immunohistochemistry. RESULTS: The number of dopaminergic neurons protected by engineered cells increased at least by 95.4% in comparison with the control cells (P < 0.01). The number of dopaminergic neurons protected by engineered cells against MPP+ toxicity increased 9.5-10.8 times (P < 0.01). CONCLUSION: A kind of engineered SH-SY5Y cells secreting human GDNF has been constructed successfully. These cells obviously protect dopaminergic neurons against degeneration and MPP+ toxication and may play an important role in gene therapy of Parkinson's disease.

1-Methyl-4-phenylpyridinium↗

PubMed2001

Consequence of beta 16 and beta 112 replacements on the kinetics of hemoglobin assembly.

The rates of alpha/beta monomer combination of four beta(A) variants (beta 112C --> S, beta 112C --> D, beta 112C --> T, and beta 112C --> V) in the presence and absence of beta 16G --> D (beta(J)) were measured in an attempt to assess the consequences of amino acid substitution at both a surface (beta 16) and an alpha(1)beta(1) interface (beta 112) residue on oxyhemoglobin assembly. Rates of alpha/beta monomer combination determined spectrally in 0.1 M Tris-HCl, 0.1 M NaCl, 1 mM EDTA, pH 7.4, at 21.5 degrees C differed by over 40-fold (22 +/- 2.0 to 0.49 +/- 0.1 x 10(5) M(-1) s(-1)), and were in the order: HbA beta 112S = HbJ beta 16D, beta 112S > HbA beta 112D = HbJ beta 16D, beta 112D > HbA > Hb J > HbA beta 112T = HbJ beta 16D, beta 112T > HbJ beta 16D, beta 112V > HbA beta 112V. This extensive kinetic investigation of single/double amino acid-substituted recombinant hemoglobin molecules, in conjunction with molecular modeling studies, has allowed examination of an array of unique alpha/beta subunit interactions and assembly processes.

Amino Acid Substitution↗

PubMed2001

Kinetics and morphologies of viscoelastic phase separation.

In this paper, the effects of relaxational bulk modulus and the average composition of polymers on the viscoelastic phase separation are investigated in detail. It is found that there are two typical morphologies, i.e., moving droplet phase and phase inversion, and the relaxation of the dynamical asymmetry and the amplification of the concentration fluctuation are responsible for the appearance and evolution of different morphologies of viscoelastic phase separation. It is found that, for the viscoelastic phase separation, the scattering function has two peaks. The growth exponents of the main and the secondary peaks in the late stage are almost the same and approximately 0.6, which also agrees with the experimental observations. On the other hand, the growth exponent of the secondary peak increased from approximately 0.42 to approximately 0.66 with increase of straight phi(0) from 0.275 to 0.4, in the intermediate stage.

Journal Article↗

PubMed2001

Electrophysiological effects of ibutilide in patients with accessory pathways.

BACKGROUND: Atrial fibrillation (AF) may cause life-threatening ventricular arrhythmias in patients with Wolff-Parkinson-White syndrome. We prospectively evaluated the effects of ibutilide on the conduction system in patients with accessory pathways (AP). METHODS AND RESULTS: In part I, we gave ibutilide to 22 patients (18 men, 31+/-13 years of age) who had AF during electrophysiology study, including 6 pediatric patients </=18 years of age. Ibutilide terminated AF in 21 of 22 patients (95%) during or 8+/-5 minutes after infusion and prolonged the shortest preexcited R-R interval during AF. Successful ablation was performed in all patients. In part II, ibutilide was given to 18 patients (14 men, 28+/-21 years) to assess its effects on the AP and conduction system. Ibutilide prolonged the antegrade atrioventricular node effective refractory period (ERP) (from 252+/-60 to 303+/-70 ms; P<0.02). Ibutilide caused transient loss of the delta wave in 1 patient and abolished inducible tachycardia in 2 patients, although retrograde mapping still allowed for successful AP ablation. The antegrade AP ERP prolonged from 275+/-40 to 320+/-60 ms (P<0.01), as did the antegrade AP block cycle length; the retrograde AP ERP and block cycle length similarly prolonged with ibutilide. The relative and effective refractory period of the His-Purkinje system increased in 61% of patients after ibutilide. There were no adverse side effects. CONCLUSIONS: We report the use of ibutilide in terminating AP-mediated AF, including the first report in the pediatric population. Ibutilide prolonged refractoriness of the atrioventricular node, His-Purkinje system, and AP.

Adolescent↗

PubMed2001

Human tryptase epsilon (PRSS22), a new member of the chromosome 16p13.3 family of human serine proteases expressed in airway epithelial cells.

Probing of the GenBank expressed sequence tag (EST) data base with varied human tryptase cDNAs identified two truncated ESTs that subsequently were found to encode overlapping portions of a novel human serine protease (designated tryptase epsilon or protease, serine S1 family member 22 (PRSS22)). The tryptase epsilon gene resides on chromosome 16p13.3 within a 2.5-Mb complex of serine protease genes. Although at least 7 of the 14 genes in this complex encode enzymatically active proteases, only one tryptase epsilon-like gene was identified. The trachea and esophagus were found to contain the highest steady-state levels of the tryptase epsilon transcript in adult humans. Although the tryptase epsilon transcript was scarce in adult human lung, it was present in abundance in fetal lung. Thus, the tryptase epsilon gene is expressed in the airways in a developmentally regulated manner that is different from that of other human tryptase genes. At the cellular level, tryptase epsilon is a major product of normal pulmonary epithelial cells, as well as varied transformed epithelial cell lines. Enzymatically active tryptase epsilon is also constitutively secreted from these cells. The amino acid sequence of human tryptase epsilon is 38-44% identical to those of human tryptase alpha, tryptase beta I, tryptase beta II, tryptase beta III, transmembrane tryptase/tryptase gamma, marapsin, and Esp-1/testisin. Nevertheless, comparative protein structure modeling and functional studies using recombinant material revealed that tryptase epsilon has a substrate preference distinct from that of its other family members. These data indicate that the products of the chromosome 16p13.3 complex of tryptase genes evolved to carry out varied functions in humans.

Adult↗

PubMed2001

Activation of DNA damage checkpoints in CHO cells requires a certain level of DNA damage.

DNA damage activates checkpoint controls in eukaryotic cells. It is not clear, however, whether a certain level of DNA damage is required for the activation of DNA damage checkpoints. We show here that low levels of DNA damage in Chinese hamster ovary (CHO) cells induced by short exposure to hydroxyurea (HU) did not trigger checkpoints, whereas higher levels of DNA damage caused by longer exposure to HU resulted in a cell cycle arrest. Our results argue that a threshold of DNA damage is necessary for activation of DNA damage checkpoints.

Animals↗