1
|
[Current status of diagnosis and treatment of chronic lymphocytic leukemia in China: A national multicenter survey research]. ZHONGHUA XUE YE XUE ZA ZHI = ZHONGHUA XUEYEXUE ZAZHI 2023; 44:380-387. [PMID: 37550187 PMCID: PMC10440613 DOI: 10.3760/cma.j.issn.0253-2727.2023.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Indexed: 08/09/2023]
Abstract
Objective: To understand the current status of diagnosis and treatment of chronic lymphocytic leukemia (CLL) /small lymphocytic lymphoma (SLL) among hematologists, oncologists, and lymphoma physicians from hospitals of different levels in China. Methods: This multicenter questionnaire survey was conducted from March 2021 to July 2021 and included 1,000 eligible physicians. A combination of face-to-face interviews and online questionnaire surveys was used. A standardized questionnaire regarding the composition of patients treated for CLL/SLL, disease diagnosis and prognosis evaluation, concomitant diseases, organ function evaluation, treatment selection, and Bruton tyrosine kinase (BTK) inhibitor was used. Results: ①The interviewed physicians stated that the proportion of male patients treated for CLL/SLL is higher than that of females, and the age is mainly concentrated in 61-70 years old. ②Most of the interviewed physicians conducted tests, such as bone marrow biopsies and immunohistochemistry, for patient diagnosis, in addition to the blood test. ③Only 13.7% of the interviewed physicians fully grasped the initial treatment indications recommended by the existing guidelines. ④In terms of cognition of high-risk prognostic factors, physicians' knowledge of unmutated immunoglobulin heavy-chain variable and 11q- is far inferior to that of TP53 mutation and complex karyotype, which are two high-risk prognostic factors, and only 17.1% of the interviewed physicians fully mastered CLL International Prognostic Index scoring system. ⑤Among the first-line treatment strategy, BTK inhibitors are used for different types of patients, and physicians have formed a certain understanding that BTK inhibitors should be preferentially used in patients with high-risk factors and elderly patients, but the actual use of BTK inhibitors in different types of patients is not high (31.6%-46.0%). ⑥BTK inhibitors at a reduced dose in actual clinical treatment were used by 69.0% of the physicians, and 66.8% of the physicians had interrupted the BTK inhibitor for >12 days in actual clinical treatment. The use of BTK inhibitors is reduced or interrupted mainly because of adverse reactions, such as atrial fibrillation, severe bone marrow suppression, hemorrhage, and pulmonary infection, as well as patients' payment capacity and effective disease progression control. ⑦Some differences were found in the perceptions and behaviors of hematologists and oncologists regarding the prognostic assessment of CLL/SLL, the choice of treatment options, the clinical use of BTK inhibitors, etc. Conclusion: At present, a gap remains between the diagnosis and treatment of CLL/SLL among Chinese physicians compared with the recommendations in the guidelines regarding the diagnostic criteria, treatment indications, prognosis assessment, accompanying disease assessment, treatment strategy selection, and rational BTK inhibitor use, especially the proportion of dose reduction or BTK inhibitor discontinuation due to high adverse events.
Collapse
|
2
|
Pt/MXene-Based Flexible Wearable Non-Enzymatic Electrochemical Sensor for Continuous Glucose Detection in Sweat. ACS APPLIED MATERIALS & INTERFACES 2023; 15:13290-13298. [PMID: 36862063 DOI: 10.1021/acsami.2c20543] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Wearable non-invasive sensors facilitate the continuous measurement of glucose in sweat for the treatment and management of diabetes. However, the catalysis of glucose and sweat sampling are challenges in the development of efficient wearable glucose sensors. Herein, we report a flexible wearable non-enzymatic electrochemical sensor for continuous glucose detection in sweat. We synthesized a catalyst (Pt/MXene) by the hybridization of Pt nanoparticles onto MXene (Ti3C2Tx) nanosheets with a broad linear range of glucose detection (0-8 mmol/L) under neutral conditions. Furthermore, we optimized the structure of the sensor by immobilizing Pt/MXene with a conductive hydrogel to enhance the stability of the sensor. Based on Pt/MXene and the optimized structure, we fabricated a flexible wearable glucose sensor by integrating a microfluidic patch for sweat collection onto a flexible sensor. We evaluated the utility of the sensor for the detection of glucose in sweat, and the sensor could detect the glucose change with the replenishment and consumption of energy by the body, and a similar trend was observed in the blood. An in vivo glucose test in sweat indicated that the fabricated sensor is promising for the continuous measurement of glucose, which is essential for the treatment and management of diabetes.
Collapse
|
3
|
NIR-II-Responsive CeO 2-x@HA Nanotheranostics for Photoacoustic Imaging-Guided Sonodynamic-Enhanced Synergistic Phototherapy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:5502-5514. [PMID: 35470663 DOI: 10.1021/acs.langmuir.2c00067] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The therapeutic effect of photothermal therapy (PTT) and photodynamic therapy (PDT) is severely limited because of the shallow tissue penetration depth of the first near-infrared (NIR-I) light. Multifunctional nanotheranostics irradiated by the second near-infrared (NIR-II) light have received wide interest with respect to deeper tissue penetration, and sonodynamic therapy (SDT) synergistic phototherapy can achieve the complete elimination of tumors. Herein, we successfully constructed a single NIR-II light-induced nanotheranostic using cerium oxide (CeO2-x) with abundant oxygen vacancies for photoacoustic imaging-guided SDT-enhanced phototherapy for the first time. CeO2-x with surface crystalline disorder showed extensive NIR-II region absorption and an outstanding photothermal conversion ability. In addition, the CeO2-x layer with numerous oxygen defects can promote the separation of holes and electrons by ultrasound irradiation, which can remarkably enhance the efficacy of phototherapy to achieve high-efficiency tumor ablation. CeO2-x was surface modified with hyaluronic acid (HA) to prepare CeO2-x@HA to allow active tumor targeting efficiency. Both cell and animal experiments confirmed that all-in-one CeO2-x@HA exhibited a high therapeutic efficacy of SDT-enhanced PDT/PTT under 1064 nm laser irradiation, which achieved complete tumor eradication without systemic toxicity. This study significantly broadened the application of NIR-II-responsive CeO2-x for photoacoustic imaging-mediated SDT-enhanced phototherapy to the highly efficient and precise elimination of tumors.
Collapse
|
4
|
Two new species of genus Svistella Gorochov, 1987 from China (Orthoptera: Trigonidiidae: Trigonidiinae). Zootaxa 2021; 4949:zootaxa.4949.1.10. [PMID: 33757001 DOI: 10.11646/zootaxa.4949.1.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Indexed: 11/04/2022]
Abstract
The genus Svistella contains 8 species worldwide with 7 recorded from China. In this study, we reconstructed the gene tree based on COI gene, and reported two new species, S. wuyong He sp. nov. and S. malu He sp. nov. The new species differs from allied species in color, male genitalia, songs and molecular study. The type specimens are deposited in the Museum of Biology, East China Normal University (ECNU).
Collapse
|
5
|
A new species of genus Homoeoxipha Saussure, 1874 from China (Orthoptera: Trigonidiidae: Trigonidiinae). Zootaxa 2021; 4942:zootaxa.4942.3.6. [PMID: 33757060 DOI: 10.11646/zootaxa.4942.3.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Indexed: 11/04/2022]
Abstract
The genus Homoeoxipha contains 11 species worldwide with 4 recorded from China. In this study, we reconstructed the gene tree based on COI gene, and reported one new species, H. oscillantenna He sp. nov. The new species is similar to H. eurylobus Ma, Liu Zhang, but differs in the color of fore femur and the structure of male genitalia. Calling songs and nymph morphology are also provided. The type specimens are deposited in the Museum of Biology, East China Normal University (ECNU).
Collapse
|
6
|
Topical Spilanthol Inhibits MAPK Signaling and Ameliorates Allergic Inflammation in DNCB-Induced Atopic Dermatitis in Mice. Int J Mol Sci 2019; 20:ijms20102490. [PMID: 31137528 PMCID: PMC6566832 DOI: 10.3390/ijms20102490] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 05/18/2019] [Accepted: 05/18/2019] [Indexed: 02/06/2023] Open
Abstract
Atopic dermatitis (AD) is a recurrent allergic skin disease caused by genetic and environmental factors. Patients with AD may experience immune imbalance, increased levels of mast cells, immunoglobulin (Ig) E and pro-inflammatory factors (Cyclooxygenase, COX-2 and inducible NO synthase, iNOS). While spilanthol (SP) has anti-inflammatory and analgesic activities, its effect on AD remains to be explored. To develop a new means of SP, inflammation-related symptoms of AD were alleviated, and 2,4-dinitrochlorobenzene (DNCB) was used to induce AD-like skin lesions in BALB/c mice. Histopathological analysis was used to examine mast cells and eosinophils infiltration in AD-like skin lesions. The levels of IgE, IgG1 and IgG2a were measured by enzyme-linked immunosorbent assay (ELISA) kits. Western blot was used for analysis of the mitogen-activated protein kinase (MAPK) pathways and COX-2 and iNOS protein expression. Topical SP treatment reduced serum IgE and IgG2a levels and suppressed COX-2 and iNOS expression via blocked mitogen-activated protein kinase (MAPK) pathways in DNCB-induced AD-like lesions. Histopathological examination revealed that SP reduced epidermal thickness and collagen accumulation and inhibited mast cells and eosinophils infiltration into the AD-like lesions skin. These results indicate that SP may protect against AD skin lesions through inhibited MAPK signaling pathways and may diminish the infiltration of inflammatory cells to block allergic inflammation.
Collapse
|
7
|
Spilanthol from Traditionally Used Spilanthes acmella Enhances AMPK and Ameliorates Obesity in Mice Fed High-Fat Diet. Nutrients 2019; 11:nu11050991. [PMID: 31052312 PMCID: PMC6566575 DOI: 10.3390/nu11050991] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 04/29/2019] [Accepted: 04/29/2019] [Indexed: 12/16/2022] Open
Abstract
Spilanthol (SP) is a bioactive compound found in Spilanthes acmella, giving the flowers and leaves a spicy taste. Studies found that phyto-ingredients stored in spice plants act against obesity-related diseases. SP has antimicrobial, anti-inflammatory, and analgesic properties, but the effects on obesity are not yet known. We investigated the effects of SP in differentiated adipocytes (3T3-L1 cells) and mice fed a high-fat diet (HFD). SP significantly inhibited intracellular lipid accumulation and significantly reduced the expression of lipogenesis-related proteins, including acetyl-CoA carboxylase (ACC) and fatty-acid synthase (FAS). In contrast, SP increased the expression of carnitine palmitoyltransferase (CPT)1 and AMP-activated protein kinase (AMPK) in adipocytes. However, SP suppressed the levels of cyclooxygenase-2 (COX-2), phospho-p38 (pp38), and phospho-JNK (c-Jun N-terminal kinase) (pJNK) in LPS (lipopolysaccharide)-stimulated murine pre-adipocytes. SP administered to HFD-induced obese mice via intraperitoneal injections twice a week for 10 weeks decreased body weight gain, visceral adipose tissue weight, and adipocyte size. SP inhibited lipogenic proteins FAS and ACC, and suppressed adipogenic transcription factors, enhancing lipolysis and AMPK protein expression in the liver. SP has anti-obesity effects, upregulating AMPK to attenuate lipogenic and adipogenic transcription factors.
Collapse
|
8
|
Rapid progression of thymoma in a 3-year-old-girl. FORMOSAN JOURNAL OF SURGERY 2019. [DOI: 10.4103/fjs.fjs_41_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
|
9
|
The association between subclass-specific IgG Fc N-glycosylation profiles and hypertension in the Uygur, Kazak, Kirgiz, and Tajik populations. J Hum Hypertens 2018; 32:555-563. [PMID: 29867134 DOI: 10.1038/s41371-018-0071-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 03/15/2018] [Accepted: 04/06/2018] [Indexed: 01/01/2023]
Abstract
Hypertension results from the interaction of genetic and acquired factors. IgG occurs in the form of different subclasses, of which the effector functions show significant variation. The detailed differences between the glycosylation profiles of the individual IgG subclasses may be lost in a profiling method for total IgG N-glycosylation. In this study, subclass-specific IgG Fc glycosylation profile was investigated in the four northwestern Chinese minority populations, namely, Uygur (UIG), Kazak (KZK), Kirgiz (KGZ), and Tajik (TJK), composed of 274 hypertensive patients and 356 healthy controls. The results showed that ten directly measured IgG N-glycan traits (i.e., IgG1G0F, IgG2G0F, IgG2G1FN, IgG2G1FS, IgG2G2S, IgG4G0F, IgG4G1FS, IgG4G1S, IgG4G2FS, and IgG4G2N) representing galactosylation and sialylation are significantly associated with hypertension, with IgG4 consistently showing weaker associations of its sialylation, across the four ethnic groups. We observed a modest improvement on the AUC of ROC curve when the IgG Fc N-glycan traits are added into the glycan-based model (difference between AUCs, 0.044, 95% CI: 0.016-0.072, P = 0.002). The AUC of the diagnostic model indicated that the subclass-specific IgG Fc N-glycan profiles provide more information reinforcing current models utilizing age, gender, BMI, and ethnicity, and demonstrate the potential of subclass-specific IgG Fc N-glycosylation profiles to serve as a biomarker for hypertension. Further research is however required to determine the additive value of subclass-specific IgG Fc N-glycosylation on top of biomarkers, which are currently used.
Collapse
|
10
|
Fisetin inhibits the generation of inflammatory mediators in interleukin-1β-induced human lung epithelial cells by suppressing the NF-κB and ERK1/2 pathways. Int Immunopharmacol 2018; 60:202-210. [PMID: 29758489 DOI: 10.1016/j.intimp.2018.05.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 05/04/2018] [Accepted: 05/08/2018] [Indexed: 12/28/2022]
Abstract
Fisetin, a flavone that can be isolated from fruits and vegetables, has anti-tumor and anti-oxidative properties and ameliorates airway hyperresponsiveness in asthmatic mice. This study investigated whether fisetin can suppress the expression of inflammatory mediators and intercellular adhesion molecule 1 (ICAM-1) in A549 human lung epithelial cells that were stimulated with interleukin-1β (IL-1β) to induce inflammatory responses. A549 cells were treated with fisetin (3-30 μM) and then with IL-1β. Fisetin significantly inhibited COX-2 expression and reduced prostaglandin E2 production, and it suppressed the levels of IL-8, CCL5, monocyte chemotactic protein 1, tumor necrosis factor α, and IL-6. Fisetin also significantly attenuated the expression of chemokine and inflammatory cytokine genes and decreased the expression of ICAM-1, which mediates THP-1 monocyte adhesion to inflammatory A549 cells. Fisetin decreased the translocation of nuclear transcription factor kappa-B (NF-κB) subunit p65 into the nucleus and inhibited the phosphorylation of proteins in the ERK1/2 pathway. Co-treatment of IL-1β-stimulated A549 cells with ERK1/2 inhibitors plus fisetin reduced ICAM-1 expression. Furthermore, fisetin significantly increased the effects of the protective antioxidant pathway by promoting the expression of nuclear factor erythroid-2-related factor-2 and heme oxygenase 1. Taken together, these data suggest that fisetin has anti-inflammatory effects and that it suppresses the expression of chemokines, inflammatory cytokines, and ICAM-1 by suppressing the NF-κB and ERK1/2 signaling pathways in IL-1β-stimulated human lung epithelial A549 cells.
Collapse
|
11
|
Short-term effects of customized arch support insoles on symptomatic flexible flatfoot in children: A randomized controlled trial. Medicine (Baltimore) 2018; 97:e10655. [PMID: 29768332 PMCID: PMC5976302 DOI: 10.1097/md.0000000000010655] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Limited evidence is available regarding the effects of insoles on pediatric flexible flatfoot because of the heterogeneity and low methodological quality of previous studies. The purpose of this prospective trial is to examine the short-term effects of customized arch support insoles on symptomatic flexible flatfoot in children by using the International Classification of Functioning, randomized controlled Disability, and Health (ICF) framework. METHODS This study was conducted in a rehabilitation outpatient clinic of a teaching hospital. Fifty-two children with symptomatic flexible flatfoot were included. The children in the treatment group wore customized arch support insoles for 12 weeks, whereas those in the control group did not wear the insoles. Both clinical and radiographic measurements, including the navicular drop, foot posture index, Beighton hypermobility score, talonavicular coverage angle, calcaneal inclination angle, and calcaneal-first metatarsal angle, were used for diagnosing flexible flatfoot. Physical activity (10-m normal and fast walking, stair ascent, stair descent, and chair rising), physical function, and psychometric properties (Pediatric Outcome Data Collection Instrument and Pediatric Quality of Life Inventory) were evaluated at the baseline and 12 weeks after the intervention. RESULTS Compared with the control group, the treatment group exhibited significant improvement in pain/comfort (P = .048), physical health (P = .035), stair ascent time (P = .015), upper extremity and physical function (P = .016), and transfer and basic mobility (P = .042) during the intervention period. CONCLUSION Children with flexible flatfoot who wore customized arch support insoles for 12 weeks exhibited significantly improved pain/comfort, physical health, stair ascent time, upper extremity and physical function, and transfer and basic mobility. These variables belong to the domains of body functions and structures and activity and participation in the ICF framework. However, because the groups were not comparable, additional studies with larger sample sizes should be conducted.
Collapse
|
12
|
Cell-free methylation markers with diagnostic and prognostic potential in hepatocellular carcinoma. Oncotarget 2018; 8:6406-6418. [PMID: 28031532 PMCID: PMC5351641 DOI: 10.18632/oncotarget.14115] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 12/16/2016] [Indexed: 12/30/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is a highly malignant tumor with poor prognosis and high mortality. There is a dearth of effective early diagnostic tools, so liver resection surgery and liver transplantation are the only effective medical treatments. The most commonly used marker for HCC detection is serum alpha fetoprotein (AFP), which has low sensitivity and specificity. Because aberrant DNA methylation of genes and miRNAs occurs early in most cancers, we explored whether circulating methylation markers could be promising clinical tools for HCC diagnosis. Using a whole-genome approach, we identified many hyper-methylated miRNAs in HCC. Furthermore, three abnormally methylated genes and one miRNA were combined to establish a methylation predictive model and tested for its diagnostic and prognostic potential in HCC. Using plasma samples, the predictive model exhibited high sensitivity and specificity (> 80%) for HBV-related HCC. Most importantly, nearly 75% of patients who could not be diagnosed with AFP at 20 ng/mL were detected by this model. Further, the predictive model exhibited an exceedingly high ability to predict 5-year overall survival in HCC patients. These data demonstrate the high diagnostic and prognostic potential of methylation markers in the plasma of HCC patients.
Collapse
|
13
|
Unusual presentation of a late complication in a polyacrylamide gel-injected breast. FORMOSAN JOURNAL OF SURGERY 2017. [DOI: 10.4103/fjs.fjs_24_17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
|
14
|
Successful management of primary splenic pregnancy: a case report and review of literature. CLIN EXP OBSTET GYN 2017; 44:487-488. [PMID: 29949303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Ectopic pregnancy is defined as dislocation of a fertilized ovum anywhere other than in the cavity of uterus. Generally, the common site for dislocation is within fallopian tube, accounting for 95.5% of all ectopic gestations. Abdominal pregnancy is rare with a potentially life-threatening variation that resides within peritoneal cavity and the primary splenic pregnancy is even rarer. This report describes a patient with primary splenic pregnancy, who was successfully managed after splenectomy.
Collapse
|
15
|
Velocity autocorrelation function in supercooled liquids: Long-time tails and anomalous shear-wave propagation. Phys Rev E 2016; 94:060601. [PMID: 28085468 DOI: 10.1103/physreve.94.060601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Indexed: 06/06/2023]
Abstract
Molecular dynamic simulations are performed to reveal the long-time behavior of the velocity autocorrelation function (VAF) by utilizing the finite-size effect in a Lennard-Jones binary mixture. Whereas in normal liquids the classical positive t^{-3/2} long-time tail is observed, we find in supercooled liquids a negative tail. It is strongly influenced by the transfer of the transverse current wave across the period boundary. The t^{-5/2} decay of the negative long-time tail is confirmed in the spectrum of VAF. Modeling the long-time transverse current within a generalized Maxwell model, we reproduce the negative long-time tail of the VAF, but with a slower algebraic t^{-2} decay.
Collapse
|
16
|
Decoupled length scales for diffusivity and viscosity in glass-forming liquids. Phys Rev E 2016; 94:042612. [PMID: 27841604 DOI: 10.1103/physreve.94.042612] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Indexed: 06/06/2023]
Abstract
The growth of the characteristic length scales both for diffusion and viscosity is investigated by molecular dynamics utilizing the finite-size effect in a binary Lennard-Jones mixture. For those quantities relevant to the diffusion process (e.g., the hydrodynamic value and the spatial correlation function), a strong system-size dependence is found. In contrast, it is weak or absent for the shear relaxation process. Correlation lengths are estimated from the decay of the spatial correlation functions. We find the length scale for viscosity decouples from the one of diffusivity, featured by a saturated length even in high supercooling. This temperature-independent behavior of the length scale is reminiscent of the unapparent structure change upon supercooling, implying the manifestation of configuration entropy. Whereas for the diffusion process, it is manifested by relaxation dynamics and dynamic heterogeneity. The Stokes-Einstein relation is found to break down at the temperature where the decoupling of these lengths happens.
Collapse
|
17
|
Heterogeneous diffusion, viscosity, and the Stokes-Einstein relation in binary liquids. Phys Rev E 2016; 93:052607. [PMID: 27300951 DOI: 10.1103/physreve.93.052607] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Indexed: 06/06/2023]
Abstract
We investigate the origin of the breakdown of the Stokes-Einstein relation (SER) between diffusivity and viscosity in undercooled melts. A binary Lennard-Jones system, as a model for a metallic melt, is studied by molecular dynamics. A weak breakdown at high temperatures can be understood from the collectivization of motion, seen in the isotope effect. The strong breakdown at lower temperatures is connected to an increase in dynamic heterogeneity. On relevant time scales some particles diffuse much faster than the average or than predicted by the SER. The van Hove self-correlation function allows one to unambiguously identify slow particles. Their diffusivity is even less than predicted by the SER. The time span of these particles being slow particles, before their first conversion to be a fast one, is larger than the decay time of the stress correlation. The contribution of the slow particles to the viscosity rises rapidly upon cooling. Not only the diffusion but also the viscosity shows a dynamically heterogeneous scenario. We can define a "slow" viscosity. The SER is recovered as the relation between slow diffusivity and slow viscosity.
Collapse
|
18
|
The TCA cycle transferase DLST is important for MYC-mediated leukemogenesis. Leukemia 2016; 30:1365-74. [PMID: 26876595 DOI: 10.1038/leu.2016.26] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 12/21/2015] [Accepted: 02/01/2016] [Indexed: 12/22/2022]
Abstract
Despite the pivotal role of MYC in the pathogenesis of T-cell acute lymphoblastic leukemia (T-ALL) and many other cancers, the mechanisms underlying MYC-mediated tumorigenesis remain inadequately understood. Here we utilized a well-characterized zebrafish model of Myc-induced T-ALL for genetic studies to identify novel genes contributing to disease onset. We found that heterozygous inactivation of a tricarboxylic acid (TCA) cycle enzyme, dihydrolipoamide S-succinyltransferase (Dlst), significantly delayed tumor onset in zebrafish without detectable effects on fish development. DLST is the E2 transferase of the α-ketoglutarate (α-KG) dehydrogenase complex (KGDHC), which converts α-KG to succinyl-CoA in the TCA cycle. RNAi knockdown of DLST led to decreased cell viability and induction of apoptosis in human T-ALL cell lines. Polar metabolomics profiling revealed that the TCA cycle was disrupted by DLST knockdown in human T-ALL cells, as demonstrated by an accumulation of α-KG and a decrease of succinyl-CoA. Addition of succinate, the downstream TCA cycle intermediate, to human T-ALL cells was sufficient to rescue defects in cell viability caused by DLST inactivation. Together, our studies uncovered an important role for DLST in MYC-mediated leukemogenesis and demonstrated the metabolic dependence of T-lymphoblasts on the TCA cycle, thus providing implications for targeted therapy.
Collapse
|
19
|
Effectiveness of Vestibular Rehabilitation in Hemodialysis Patients With Dizziness. Rehabil Nurs 2014; 42:125-130. [PMID: 25546482 DOI: 10.1002/rnj.198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
PURPOSE This study evaluated the effectiveness of vestibular rehabilitation (VR) for hemodialysis (HD) patients with chronic dizziness. DESIGN A single-blind, randomized controlled study was performed. METHODS Cluster-randomized sampling was used to select the experimental group from two outpatient dialysis clinics. A total of 26 patients participated in the study. Dizziness Handicap Inventory (DHI) and falls were used as outcome measures. Data were collected at baseline (T1), 3 months (T2), and 6 months (T3). FINDINGS Two-way repeated-measures ANOVA of DHI revealed a statistically significant group and time interaction. Dizziness handicap outcome was significantly reduced over time in the experimental group (DHI total score, T1 = 35.29, T2 = 32.86, T3 = 27.86, p = .001). CONCLUSIONS VR exercise instructed by nurses can be effective in alleviating handicap imposed by dizziness in dialysis patients. CLINICAL RELEVANCE Nurses are encouraged to learn VR as a simple exercise to improve well-being in dialysis patients with chronic dizziness.
Collapse
|
20
|
Intraluminal duodenal diverticulum in a child concomitant with an entrapped coin and a duodenal polyp. FORMOSAN JOURNAL OF SURGERY 2014. [DOI: 10.1016/j.fjs.2014.08.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
21
|
Chronic streptococcosis in Nile tilapia, Oreochromis niloticus (L.), caused by Streptococcus agalactiae. JOURNAL OF FISH DISEASES 2014; 37:757-763. [PMID: 23952820 DOI: 10.1111/jfd.12146] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 05/27/2013] [Accepted: 05/28/2013] [Indexed: 06/02/2023]
|
22
|
Abstract
BACKGROUND Dual-energy digital mammography (DEDM), involving a combination of high-energy (HE) and low-energy (LE) images, has been investigated as offering a potential improvement in microcalcification detection obscured by overlapping tissue structures. PURPOSE To explore the possibility to improve detection of microcalcifications using the DEDM technique. MATERIAL AND METHODS Three DEDM protocols were performed by adjusting the effective tube current time product (mAs) of LE image at the same (100%), one half (50%), and one-quarter (25%) of that used in HE image acquisition, named DEDM100%, DEDM50%, and DEDM25%, respectively. A single-energy digital mammography (SEDM) method was also used as a control. A total of 525 regions of interest (ROIs) were used to compare the performance of the DEDM to that of SEDM using free-response receiver-operating characteristic (FROC) and areas under the FROC curve (Az). RESULTS All DEDM protocols ranked significantly higher than the SEDM method (P < 0.001). The true-positive fraction was 0.90 for an average of 0.017-0.042 false-positive per image using the DEDM100%, 0.017-0.114 using the DEDM50%, 0.021-0.148 using the DEDM25%, and 0.134-0.422 using the SEDM. The estimated Az values were 0.915-0.940, 0.867-0.935, 0.824-0.930, and 0.567-0.673, respectively. CONCLUSION The DEDM50% protocol provided a trade-off benefit between accurate microcalcification detectability and radiation dose for any tissue density. Therefore, the DEDM50% has the potential to minimize excess radiation dose without a negative impact on image quality which could improve earlier diagnosis of breast cancer.
Collapse
|
23
|
Unusual imaging features of completely isolated enteric duplication in a child. Pediatr Radiol 2012; 42:1142-4. [PMID: 22476620 DOI: 10.1007/s00247-012-2380-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Revised: 01/01/2012] [Accepted: 01/16/2012] [Indexed: 10/28/2022]
Abstract
We report a case of completely isolated enteric duplication in an 18-month-old boy in whom US revealed a reniform abdominal mass with a pseudokidney sign that had no connection to adjacent organs. Distinctive histopathological changes of the duplication account for these unusual imaging features. Our case represents a diagnostic challenge in this rare entity. To our knowledge, this is a unique case.
Collapse
|
24
|
Structural signature of plastic deformation in metallic glasses. PHYSICAL REVIEW LETTERS 2011; 106:135503. [PMID: 21517395 DOI: 10.1103/physrevlett.106.135503] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Indexed: 05/30/2023]
Abstract
The structure feature of a model CuZr metallic glass during deformation is investigated by molecular dynamics simulations. A spatially heterogeneous irreversible rearrangement is observed in terms of nonaffine displacement. We find that regions with smaller nonaffine displacement have more Voronoi pentagons, while in those with larger nonaffine displacement other types of faces are more populated. We use the degree of local fivefold symmetry (LFFS) as the structural indicator to predict plastic deformation of local structures and find that the plastic events prefer to be initiated in regions with a lower degree of LFFS and propagate toward regions with a higher degree of LFFS.
Collapse
|
25
|
Sonographic Imaging of Meniscal Subluxation in Patients with Radiographic Knee Osteoarthritis. J Formos Med Assoc 2007; 106:700-7. [PMID: 17908659 DOI: 10.1016/s0929-6646(08)60031-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND/PURPOSE This study was undertaken to describe the sonographic features of meniscal subluxation in the weight-bearing position and to determine any association between meniscal subluxation and radiographic osteoarthritis. METHODS In total, 238 knees with symptoms were examined successfully with weight-bearing anteroposterior and lateral radiographs and high resolution ultrasonography. The radiographs were examined to determine whether participants had radiographic osteoarthritis, graded using the Kellgren-Lawrence Scale. The degree of subluxation of the medial meniscus in each knee was measured using high resolution ultrasound with a 10-MHz linear transducer, at the level of the medial collateral ligament in weight-bearing condition. The degree of subluxation was compared in knees with the presence or absence of radiographic osteoarthritis using Students t test. Additional analysis between knees with early and advanced radiographic osteoarthritis was also performed. RESULTS Meniscal subluxation for knees with (n = 141) and without (n = 97) radiographic signs of osteoarthritis were 4.3 1.9 mm and 0.7 0.6 mm, respectively. The difference was highly significant (p < 0.001). After age adjustment, the medial meniscal subluxation of age-matched subjects were 4.8 1.7 mm for knees with radiographic osteoarthritis (n = 43) and 1.0 0.8 mm for knees without such changes (n = 43). The difference between the two groups was still significant (p < 0.001). The greatest meniscal subluxation was seen in knees with advanced radiographic signs of osteoarthritis; no knee with osteoarthritic changes on radiographs had an undisplaced meniscus. CONCLUSION Meniscal subluxation is a prominent feature on weight-bearing sonographic imaging in patients with radiographic osteoarthritis and could be considered as a risk factor for the development of knee osteoarthritis. By using musculoskeletal ultrasonography, one can detect this occult meniscal derangement early before the appearance of radiographic signs of osteoarthritis.
Collapse
|
26
|
AVATAR: a database for genome-wide alternative splicing event detection using large scale ESTs and mRNAs. Bioinformation 2005; 1:16-8. [PMID: 17597845 PMCID: PMC1891626 DOI: 10.6026/97320630001016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Revised: 04/20/2005] [Accepted: 04/20/2005] [Indexed: 11/23/2022] Open
Abstract
In the past years, identification of alternative splicing (AS) variants has been gaining momentum. We developed AVATAR,
a database for documenting AS using 5,469,433 human EST sequences and 26,159 human mRNA sequences. AVATAR contains
12000 alternative splicing sites identified by mapping ESTs and mRNAs with the whole human genome sequence. AVATAR
also contains AS information for 6 eukaryotes. We mapped EST alignment information into a graph model where exons
and introns are represented with vertices and edges, respectively. AVATAR can be queried using, (1) gene names,
(2) number of identified AS events in a gene, (3) minimal number of ESTs supporting a splicing site, etc. as search
parameters. The system provides visualized AS information for queried genes.
Collapse
|
27
|
Community-based multiple screening model: design, implementation, and analysis of 42,387 participants. Cancer 2004; 100:1734-43. [PMID: 15073864 DOI: 10.1002/cncr.20171] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Multiple disease screening may have several advantages over single disease screening because of the economics of scale, with the high yield of detecting asymptomatic diseases, the identification of multiple diseases or risk factors simultaneously, the enhancement of the attendance rate, and the efficiency of follow-up. METHODS An integrated model of community-based multiple screening was designed and conducted between 1999 and 2001 in Keelung, Taiwan. The authors used a Papanicolaou (Pap) smear screening program as a base to integrate other screening regimens encompassing four other neoplastic diseases and three nonneoplastic chronic diseases. Screening methods, the interscreening interval, and the follow-up for each screening regimen were designed based on evidence-based literature and current national screening policy. RESULTS A total of 42,387 subjects participated in the screening activities. A 25% increase in the attendance rate for Pap smear screening was demonstrated after the introduction of multiple disease screening programs. At the first screen, this program yielded a total of 677 asymptomatic neoplasms (16.0 per 1000), including a large proportion of precancerous lesions and small presymptomatic tumors without lymph node involvement. The association between the occurrence of neoplasm and the presence of comorbid nonneoplastic chronic disease was found to be statistically significant (odds ratio, 1.64; 95% confidence interval, 1.38-1.94 [P < 0.05]). The authors also identified 5314 subjects with metabolic syndrome who were at a greater risk for colorectal and oral neoplasias. CONCLUSIONS The results of the current study demonstrate that an outreach and community-based multiple screening program not only enhances attendance rates but also has a high yield of early cases of various diseases simultaneously, and provides a natural opportunity to elucidate the correlation between neoplastic disease and nonneoplastic chronic disease.
Collapse
|
28
|
Left cervical aortic arch with aneurysm and obstruction: three-dimensional computed tomographic angiography and magnetic resonance angiographic appearance. Int J Cardiovasc Imaging 2002; 18:463-8. [PMID: 12537416 DOI: 10.1023/a:1021155625397] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cervical arch is a rare congenital anomaly presumed to result from persistence of the third aortic arch and regression of the normal fourth arch. Rather rare is cervical aortic arch associated with aneurysm and obstruction, with eight known cases reported. Definitive diagnosis with a noninvasive imaging modality is desirable and very important to prevent the need for disaster intervention. We present two cases of a pulsatile mass in the left supraclavicular region. Three-dimensional computed tomographic angiography and magnetic resonance angiography clearly showed a left-sided cervical aortic arch (Haughton type D) with arch aneurysm and coarctation (pseudocoarctation).
Collapse
|
29
|
Abstract
A novel in vivo expression technology (IVET) was performed to identify Klebsiella pneumoniae CG43 genes that are specifically expressed during infection of BALB/c mice. The IVET employed a UDP glucose pyrophosphorylase (galU)-deficient mutant of K. pneumoniae which is incapable of utilizing galactose and synthesizing capsular polysaccharide, as demonstrated by its low virulence to BALB/c mice and a white nonmucoid colony morphology on MacConkey-galactose agar. By using a functional galU gene as the reporter, an IVE promoter could render the galU mutant virulent while maintaining the white nonmucoid colony phenotype. A total of 20 distinct sequences were obtained through the in vivo selection. Five of them have been identified previously as virulence-associated genes in other pathogens, while another five with characterized functions are involved in regulation and transportation of nutrient uptake, biosynthesis of isoprenoids, and protein folding. No known functions have been attributed to the other 10 sequences. We have also demonstrated that 2 of the 20 IVE genes turn on under iron deprivation, whereas the expression of another five genes was found to be activated in the presence of paraquat, a superoxide generator.
Collapse
|
30
|
Abstract
Klebsiella pneumoniae is a common cause of septicemia and urinary tract infections. The PCR-supported genomic subtractive hybridization was employed to identify genes specifically present in a virulent strain of K. pneumoniae. Analysis of 25 subtracted DNA clones has revealed 19 distinct nucleotide sequences. Two of the sequences were found to be the genes encoding the transposase of Tn3926 and a capsule polysaccharide exporting enzyme. Three sequences displayed moderate homology with bvgAS, which encodes a two-component signal transduction system in Bordetella pertussis. The rest of the sequences did not exhibit homology with any known genes. The distribution of these novel sequences varied greatly in K. pneumoniae clinical isolates, reflecting the heterogeneous nature of the K. pneumoniae population.
Collapse
|
31
|
Breast cancer detection using magnetic resonance imaging in breasts injected with liquid silicone. Plast Reconstr Surg 1999; 104:2116-20. [PMID: 11149777 DOI: 10.1097/00006534-199912000-00026] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Two patients who had received silicone injections in their breasts several years ago presented with breast complaints. Excluding cancer in these patients was very difficult. Mammograms were very difficult to interpret, as were the physical findings. Carcinoma was successfully detected by magnetic resonance imaging. When women who underwent the injudicious injection of silicone reach the cancer-prone age, the examining physicians should have a greater awareness of the detection and management of carcinoma coexistent with silicone mastopathy. We think that MRI is potentially valuable in the evaluation of the breast lesions; it plays an important role in the detection of breast cancer in breasts augmented with liquid silicone.
Collapse
|
32
|
Characterization of a putative Pseudomonas UDPglucose pyrophosphorylase. PROCEEDINGS OF THE NATIONAL SCIENCE COUNCIL, REPUBLIC OF CHINA. PART B, LIFE SCIENCES 1999; 23:74-84. [PMID: 10420655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
A UDP-glucose pyrophosphorylase encoding gene was identified through functional complementation screening by using an Escherichia coli galU mutant. Sequence analysis of the gene indicated that it is most likely derived from a Pseud monas sp. The gene is located immediately upstream and transcribed in the same direction of the gor (glutathione reductase) gene and is capable of encoding a protein 30,943 daltons in size. The gene product synthesized in Escherichia coli was purified and its biochemical properties characterized. The recombinant UDP-glucose pyrophosphorylase exhibited a molecular weight of 130 kDa, suggesting a tetrameric organization of the gene product. Two mutant forms of the enzyme were identified. The activity of the mutant enzyme with a tyrosine to histidine (Y26 1H) substitution was found to be greatly reduced. On the other hand, the tyrosine to cysteine (Y84C) substitution resulted in an enzyme that functions normally at 37 degrees C but rather poorly at temperatures lower than 30 degrees C.
Collapse
|
33
|
Characterization of mdcR, a regulatory gene of the malonate catabolic system in Klebsiella pneumoniae. J Bacteriol 1999; 181:2302-6. [PMID: 10094715 PMCID: PMC93650 DOI: 10.1128/jb.181.7.2302-2306.1999] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Klebsiella pneumoniae mdcR gene, which encodes a LysR-type regulator, was overexpressed in Escherichia coli. Purified MdcR was found to bind specifically to the control region of either the malonate decarboxylase (mdc) genes or mdcR. We have also demonstrated that MdcR is an activator of the expression of the mdc genes, whereas it represses the transcription of the putative control region of mdcR, PmdcR, indicating a negative autoregulatory control.
Collapse
|
34
|
Outbreak of Candida parapsilosis fungemia in neonatal intensive care units: clinical implications and genotyping analysis. Infection 1999; 27:97-102. [PMID: 10219638 DOI: 10.1007/bf02560505] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
During a 5-month period, 17 infants hospitalized in neonatal intensive care units of a medical center and a branch hospital developed 18 episodes of Candida parapsilosis fungemia. The mean age at onset was 35 days. Prior to fungemia, all the infants had received hyperalimentation and antibiotics, and 15 infants had had central venous catheters. The presenting symptoms were variable but only vague in 40% of the episodes. Despite administration of antifungal agents, subsequent eradication of fungemia was achieved in only two-thirds of the episodes. None of the environmental samples was positive for C. parapsilosis, while 20% of hand-washing samples of staff working in both units yielded this microorganism. Four genotypes with two main types were identified from 14 outbreak strains and eight genotypes from 14 hand-washing strains, with one type predominant. The results suggest that C. parapsilosis fungemia increases the morbidity and mortality of neonates but does not cause acute lethal events. The outbreak was caused by two main genotypes, possibly via cross-infection by the hands of health care workers.
Collapse
|
35
|
Identification of a novel family of human Rab-like small GTP-binding proteins. PROCEEDINGS OF THE NATIONAL SCIENCE COUNCIL, REPUBLIC OF CHINA. PART B, LIFE SCIENCES 1999; 23:38-44. [PMID: 9949723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The presence of a novel family of Rab-like proteins (Rlp) in the human genome is reported. The gene encoding the Rlp-2 was isolated from a human lymphocyte genomic library. The Rlp-2 gene is intronless and was mapped to chromosome Xq21.3 using fluorescence in situ hybridization. Several cDNA clones encoding the Rlp-1 were identified in a human hippocampus lambda library. Northern analysis revealed a 2.1-kb transcript of Rlp-1 expressed predominantly in brain, heart and skeletal muscle. The transcript was also observed in all examined regions of the human brain at a similar level. An additional gene, termed Rlp-3, which is highly related to Rlp-1 and Rlp-2, was found in the GenBank Data Base. The predicted molecular mass for Rlp is approximately 31 kDa and is consistent with that of Rlp-1 synthesized in Escherichia coli.
Collapse
|
36
|
Abstract
The role of smooth muscle [Ca2+]i and membrane potential for the relaxation to hypercapnic (increased CO2) and normocapnic (unchanged CO2) acidosis is not complete understood. It is often stated that membrane hyperpolarization plays an important role but this has not been vigorously tested. In this study we investigated isolated rat cerebral small arteries under isobaric conditions. Lumen diameter was measured simultaneously with either [Ca2+]i or membrane potential, and acidosis was induced by increasing PCO2 or reducing HCO3- of the bathing solution or by adding HCI to a nominally bicarbonate-free solution. Confocal microscopy verified loading of smooth muscle cells with fluorescent dyes. Acidosis always reduced myogenic tone at transmural pressures between 20 and 120 mmHg. Acidification at a transmural pressure of 40 mmHg caused an increase in diameter and a decrease in [Ca2+]i. This was also seen in the presence of L-NNA and after depolarization with 50 mM K+. The response to hypercapnic and normocapnic acidosis was similar. However, while hypercapnic acidosis caused hyperpolarization, normocapnic acidosis caused depolarization. Dilatation, decrease of [Ca2+]i and depolarization, was also seen with reduction of pH in bicarbonate-free solution. We conclude that the isobaric relaxation to both hypercapnic and normocapnic acidosis is most likely mediated by a reduction of [Ca2+]i. Membrane potential may on the other hand not play a major role for this reduction of [Ca2+]i and it is possible that molecular CO2 has an effect on the membrane potential.
Collapse
|
37
|
cDNA cloning and expression analysis of the human UDPglucose dehydrogenase. PROCEEDINGS OF THE NATIONAL SCIENCE COUNCIL, REPUBLIC OF CHINA. PART B, LIFE SCIENCES 1998; 22:166-72. [PMID: 9850599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
A cDNA clone encoding the human UDPglucose dehydrogenase was isolated from a liver cDNA library. The cDNA is 2,355 bp in length with an open reading frame which is capable of encoding a protein of 494 residues. The predicted primary sequence of the gene product is in good agreement with that of the bovine enzyme determined previously found by means of protein sequencing. Two major transcripts of the UDPglucose dehydrogenase gene with sizes of 2.8 and 2.35 kb, respectively, were observed by Northern analysis. The gene was found to be expressed in a variety of tissues with the highest level in liver, consistent with the physiological function of the enzyme in excretion of endo- and xenobiotics compounds.
Collapse
|
38
|
Outbreak of Candida albicans fungaemia in a neonatal intensive care unit. SCANDINAVIAN JOURNAL OF INFECTIOUS DISEASES 1998; 30:137-42. [PMID: 9730299 DOI: 10.1080/003655498750003519] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
During a 4-month period, 9 premature infants hospitalized in a neonatal intensive care unit (NICU) developed Candida albicans fungaemia. All 9 infants received antifungal agents. Fluconazole was administered in 7 patients and successfully eradicated this organism in 6 with no adverse effects. For epidemiological investigation, 64 environmental specimens and hand-washings of all 54 staff members involved in the NICU were examined for the presence of this organism. No C. albicans could be identified from environmental sources, while the hand-washing of 1 nurse was C. albicans-positive. Two genotyping methods, including electrophoretic karyotyping using contour-clamped homogeneous electric field gel electrophoresis and polymerase chain reaction-based direct sequencing of rRNA gene, were used in the analysis of the isolates recovered from blood cultures of the infants, the hand-washing of the nurse and 7 control isolates. Both methods yielded comparable results and revealed that all 13 isolates from infected infants as well as the isolate from hand washing of the nurse were of the same genotype while the control isolates were distinct. These results suggest that the outbreak of C. albicans fungaemia was caused by a particular strain and possibly via cross-infection. In addition, we showed that fluconazole seemed to be safe and effective in treating C. albicans fungaemia in neonates, although the data were limited.
Collapse
|
39
|
Effect of acidosis on tension and [Ca2+]i in rat cerebral arteries: is there a role for membrane potential? THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 274:H655-62. [PMID: 9486271 DOI: 10.1152/ajpheart.1998.274.2.h655] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The cellular mechanism responsible for the reduction of tension in cerebral small arteries to acidosis is not known. In this study the role of smooth muscle intracellular Ca2+ concentration ([Ca2+]i) and membrane potential for the relaxation to acidosis was investigated in isolated rat cerebral small arteries. Isometric force was measured simultaneously with [Ca2+]i (fura 2) or with membrane potential (intracellular microelectrodes), and acidosis was induced by increasing PCO2 or reducing HCO3- of the bathing solution. Both hypercapnic and normocapnic acidosis were associated with a reduction of intracellular pH [measured with 2',7'-bis-(carboxyethyl)-5 (and -6)-carboxyfluorescein], caused relaxation, and reduced [Ca2+]i. However, whereas hypercapnic acidosis caused hyperpolarization, normocapnic acidosis was associated with depolarization. It is concluded that a reduction of [Ca2+]i is in part responsible for the direct effect of the acidosis on the vascular smooth muscle both during normo- and hypercapnia. The mechanism responsible for the reduction of [Ca2+]i differs between the hypercapnic and normocapnic acidosis, being partly explained by hyperpolarization during hypercapnic acidosis, whereas it is seen despite depolarization during normocapnic acidosis.
Collapse
|
40
|
Holocord intramedullary spinal cord astrocytoma: report of one case. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI ZA ZHI [JOURNAL]. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI 1998; 39:48-50. [PMID: 9553293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Intramedullary spinal cord astrocytoma in infants is relatively uncommon. Its occurrence is usually confined to the cervical and cervicothoracic regions. In this paper, we report on the case of a 4-month old male infant with low grade holocord intramedullary spinal cord astrocytoma. He had developed progressive weakness of the lower extremities over a month period. Neurological examination revealed flaccid paraplegia as well as complete loss of all modalities of sensation below the T10 level. MRI revealed a large intramedullary mass which was found to be an intramedullary astrocytoma at surgery. This case report presents the clinical features, radiographic findings, and treatment and outcome for this patient together with a review of relevant literature.
Collapse
|
41
|
Abstract
In this paper, the control of vascular smooth muscle intracellular pH (pHi) and the mechanisms of importance for the vasodilation to acidosis are reviewed. The three transport pathways of importance for the control of pHi are a sodium-coupled bicarbonate transport, a Na,H-exchanger and a Cl,HCO3- exchange. While the two latter pathways are present in all smooth muscle cells studied, the sodium-coupled bicarbonate transport may be present in two forms which are either coupled to chloride efflux or are independent of chloride. The chloride-independent pathway seems electroneutral, indicating a 1:1 stoichiometry. All three transporters can be activated by vasoactive hormones and the second messengers involved are under intense investigation. With respect to the mechanisms involved in the vasodilation to acidosis, there seems to be a nitric oxide-dependent pathway as well as a direct effect of acidosis on the smooth muscle cells. In some preparations, prostanoids may also be involved. The direct vasodilator effect of acidosis is probably mediated through reduction of extracellular pH and the acidosis is associated with a reduction of the intracellular calcium concentration, which could explain the reduction of smooth muscle tone.
Collapse
|
42
|
Identification and characterization of acoK, a regulatory gene of the Klebsiella pneumoniae acoABCD operon. J Bacteriol 1997; 179:1497-504. [PMID: 9045805 PMCID: PMC178858 DOI: 10.1128/jb.179.5.1497-1504.1997] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
By using transposon insertional mutagenesis and deletion analyses, a recombinant clone containing the region upstream of the acoABCD operon of Klebsiella pneumoniae was found to be required for acetoin-inducible expression of the operon in Escherichia coli. The nucleotide sequence of the region was determined, and it displayed an open reading frame of 2,763 bp that is transcribed divergently to the acoABCD operon. This gene, designated acoK, is capable of encoding a protein with an overall 58.4% amino acid identity with MalT, the transcriptional activator of the E. coli maltose regulon. A conserved sequence for nucleotide binding at the N-terminal region, as well as a helix-turn-helix motif belonging to the LuxR family of transcriptional regulators at the C terminus, was also identified. Primer extension analysis identified two transcription initiation sites, S1 and S2, located 319 and 267 bp, respectively, upstream of the putative start codon of acoK. Several copies of NtrC recognition sequence [CAC-(N11 to N18)-GTG] were found in the promoter regions of both the acoK gene and the acoABCD operon. Acetoin-dependent expression of the acoABCD operon could be restored in the E. coli acoK mutants by supplying a plasmid carrying an intact acoK, suggesting a transactivating function of the gene product. The AcoK protein overproduced in E. coli was approximately 100 kDa, which is in good agreement with the molecular mass deduced from the nucleotide sequence. A specific DNA binding property and an ATPase activity of the purified AcoK were also demonstrated.
Collapse
|
43
|
Localization of the human UGP2 gene encoding the muscle isoform of UDPglucose pyrophosphorylase to 2p13-p14 by fluorescence in situ hybridization. Genomics 1997; 39:414-6. [PMID: 9119383 DOI: 10.1006/geno.1996.4426] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
44
|
Anti-lipid peroxidation of gomisin J on liver mitochondria and cultured myocardial cells. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1996; 17:538-41. [PMID: 9863151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
AIM To study the influences of gomisin J on lipid peroxidation and calcium paradox. METHODS Using two in vitro models of rat liver mitochondria membrane lipid peroxidation (LPO) and cultured myocardial cells. RESULTS Gomisin J inhibited Fe2+/ascorbic acid and ADP/NADPH-induced LPO with IC50 (95% confidence limits) 5.5 (4.5-6.7) and 4.7 (2.8-7.8) mumol.L-1, respectively, when cultured myocardial cells preincubated with Ca(2+)-free medium for 2 min were incubated with normal medium containing Ca2+, a marked increase of malondialdehyde (MDA) formation occurred and gomisin J 10 mumol.L-1 protected myocardial cells through decreasing MDA formation. CONCLUSION Gomisin J inhibits LPO in rat liver mitochondria and protects cultured myocardial cells from being injured by calcium paradox.
Collapse
|
45
|
An improved assay for UDPglucose pyrophosphorylase and other enzymes that have nucleotide products. EXPERIENTIA 1996; 52:568-72. [PMID: 8698091 DOI: 10.1007/bf01969730] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
UDPglucose pyrophosphorylase catalyses the interconversion UDPglucose plus pyrophosphate and glucose 1-phosphate plus UTP. Several assay methods for this enzyme have been described but the only one that can be used to investigate the specificity with respect to various UDPsugars is based on coupling to UTP formation. This assay employs phosphoglycerate kinase to catalyse the formation 1,3- bisphosphoglycerate which is then used to oxidise NADH in the presence of glyceraldehyde 3-phosphate dehydrogenase. We have found that the activity of phosphoglycerate kinase towards UTP is low which limits the usefulness of the assay to very low rates, in agreement with the published recommendation of Hansen et al. Here it is shown that the dynamic range of the assay is increased by more than five fold on addition of nucleoside diphosphate kinase and ADP, which convert UTP to the preferred phosphoglycerate kinase substrate, ATP. It is also shown that the improved assay is suitable for enzymes with other nucleotide triphosphate products.
Collapse
|
46
|
Identification and characterization of the acoD gene encoding a dihydrolipoamide dehydrogenase of the Klebsiella pneumoniae acetoin dehydrogenase system. J Biochem 1996; 119:1118-23. [PMID: 8827447 DOI: 10.1093/oxfordjournals.jbchem.a021357] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The acoD gene, which encodes a dihydrolipoamide dehydrogenase component of the acetoin dehydrogenase enzyme system of Klebsiella pneumoniae was isolated and the nucleotide sequence determined. The gene is capable of encoding a protein of 465 amino acid residues with conserved binding domains for NAD and FAD, and two redox-active cysteine residues. The acoD gene product exhibited a Michaelis constant of 170 microM for NAD, while NADP can not be used as a substrate. The purified enzyme appeared to be a dimer of the acoD gene product. It did not associate tightly with the E1 and E2 components of either acetoin dehydrogenase or 2-oxoglutarate dehydrogenase to form an active multi-enzyme complex.
Collapse
|
47
|
Abstract
Non-mucoid mutants of a Klebsiella pneumoniae wild type strain CG43 were generated by transposon mutagenesis. One of the mutants was incapable of fermenting galactose and was designated CG43-17. Alterations of the bacterial surface including capsule, lipopolysaccharides, and several species of outer membrane proteins were noted. The mutant was avirulent to mice and became highly sensitive to human serum. The defects could not be complemented by the gaIETK operon. Diminished activity of UDP-glucose pyrophosphorylase in CG43-17 suggested that it is a gaIU mutant. This possibility was confirmed because the parental phenotypes could be fully restored in the mutant by transforming it with a human liver cDNA encoding UDP-glucose pyrophosphorylase.
Collapse
|
48
|
Abstract
Consistent with previous results, overexpression of rabbit skeletal muscle glycogen synthase in COS cells did not lead to overaccumulation of glycogen unless activating Ser-->Ala mutations were present at key regulatory phosphorylation sites 2 (Ser7) and 3a (Ser644) in the enzyme. In addition, we found that expression of glycogenin, glycogen branching enzyme, or UDP-glucose pyrophosphorylase alone in COS cells had no effect on the glycogen level. However, coexpression of the hyperactive 2,3a glycogen synthase mutant with either glycogenin or UDP-glucose pyrophosphorylase led to higher glycogen accumulation than that obtained from the expression of glycogen synthase alone. Coexpression of glycogenin with the 2,3a mutant of glycogen synthase led to the appearance of glycogenin with a lower molecular weight suggestive of reduced glucosylation. Increased glycogen synthesis may lead to competition between glycogenin and glycogen synthase for their common substrate UDP-glucose. In summary, we conclude that (i) glycogen synthase is a primary rate-limiting enzyme of glycogen biosynthesis in COS cells, (ii) that phosphorylation of glycogen synthase is regulatory for glycogen accumulation, and (iii) once glycogen synthase is activated, the reaction mediated by UDP-glucose pyrophosphorylase can become rate-determining.
Collapse
|
49
|
The importance of conserved residues in human liver UDPglucose pyrophosphorylase. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 236:723-8. [PMID: 8612650 DOI: 10.1111/j.1432-1033.1996.t01-1-00723.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Comparison of the amino acid sequences of five eukaryotic UDPglucose pyrophosphorylases has identified a number of conserved residues that may be important for substrate binding or catalysis. Using the cloned cDNA for the human liver enzyme, we have investigated the role of several of these residues by site-directed mutagenesis. Changing the single conserved cysteine (residue 123) to serine resulted in an active enzyme, as did mutating the single concerned histidine (residue 266) to arginine. The two conserved tryptophans were each altered to serine; W218S is active while W333S is not. In the latter case, the enzyme does not appear to fold correctly, and a similar result was obtained by mutation to lysine at one (residue 391) of the four conserved arginines. The other three arginines are not essential, as judged by the observation that R389H, R422Q and R445H are all active. The kinetic properties of each active mutant were investigated and in most cases were found to be similar to those of wild-type. The most dramatic change is a sevenfold increase in the Km for magnesium pyrophosphate with C123S. Overall, none of these conserved residues appears to be essential for activity, although such a role cannot be ruled out for W333 and R391 where mutation resulted in defective folding.
Collapse
|
50
|
Sequence differences between human muscle and liver cDNAs for UDPglucose pyrophosphorylase and kinetic properties of the recombinant enzymes expressed in Escherichia coli. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 235:173-9. [PMID: 8631325 DOI: 10.1111/j.1432-1033.1996.00173.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
UDP-Glc pyrophosphorylase (EC 2.7.7.9) catalyses the interconversion of MgUTP plus Glc1P and UDP-Glc plus MgPPi. Complementation of an Escherichia coli strain lacking this activity has allowed isolation of cDNA encoding this enzyme from a human muscle library. Two forms were identified and the nucleotide sequence of each was determined; they were found to differ only in the 5' region and we suggest that these arise from the use of a different first exon in the two transcripts. These nucleotide sequences are different from that of the cDNA which was isolated previously from a human liver library [Peng, H.-L. & Chang, H.-Y. (1993) FEBS Lett. 329, 153-158] and it is proposed that these liver and muscle forms are derived from different genes. The cDNA for muscle form I, muscle form II, the liver form, and the liver form fused to part of the lacZ gene were expressed in Escherichia coli and the kinetic properties of each enzyme were characterised. Muscle form I and the LacZ/liver fusion enzyme exhibit Michaelis-Menten kinetics towards all substrates while muscle form II has a sigmoidal dependence of rate upon the concentration of MgPPi. The liver form shows Michaelis-Menten kinetics towards MgUTP. For the remaining three substrates, complex kinetics were observed involving a combination of sigmoidicity at low substrate concentration and partial inhibition at high substrate concentration.
Collapse
|