Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 101
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Phys Rev Lett ; 133(2): 025101, 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-39073957

ABSTRACT

Gyrokinetic tokamak plasmas can exhibit intrinsic toroidal rotation driven by the residual stress. While most studies have attributed the residual stress to the parallel-momentum flux from the turbulent E×B motion, the parallel-momentum flux from the drift-orbit motion (denoted Π_{∥}^{D}) and the E×B-momentum flux from the E×B motion (denoted Π_{E×B}) are often neglected. Here, we use the global total-f gyrokinetic code XGC to study the residual stress in the core and the edge of a DIII-D H-mode plasma. Numerical results show that both Π_{∥}^{D} and Π_{E×B} make up a significant portion of the residual stress. In particular, Π_{∥}^{D} in the core is higher than the collisional neoclassical level in the presence of turbulence, while in the edge it represents an outflux of countercurrent momentum even without turbulence. Using a recently developed "orbit-flux" formulation, we show that the higher-than-neoclassical-level Π_{∥}^{D} in the core is driven by turbulence, while the outflux of countercurrent momentum from the edge is mainly due to collisional ion orbit loss. These results suggest that Π_{∥}^{D} and Π_{E×B} can be important for the study of intrinsic toroidal rotation.

2.
Phys Rev Lett ; 132(23): 235102, 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38905687

ABSTRACT

Multimachine empirical scaling predicts an extremely narrow heat exhaust layer in future high magnetic field tokamaks, producing high power densities that require mitigation. In the experiments presented, the width of this exhaust layer is nearly doubled using actuators to increase turbulent transport in the plasma edge. This is achieved in low collisionality, high confinement edge pedestals with their gradients limited by turbulent transport instead of large-scale, coherent instabilities. The exhaust heat flux profile width and divertor leg diffusive spreading both double as a high frequency band of turbulent fluctuations propagating in the electron diamagnetic direction doubles in amplitude. The results are quantitatively reproduced in electromagnetic XGC particle-in-cell simulations which show the heat flux carried by electrons emerges to broaden the heat flux profile, directly supported by Langmuir probe measurements.

3.
Hong Kong Med J ; 28(4): 315-320, 2022 08.
Article in English | MEDLINE | ID: mdl-33750741

ABSTRACT

The novel coronavirus disease (COVID-19) may result in acute respiratory distress syndrome and respiratory failure, necessitating mechanical respiratory support. Healthcare professionals are exposed to a particularly high risk of contracting the virus while providing resuscitation and respiratory support, which may in turn result in grave consequences and even death. Although COVID-19 has been shown to cause milder disease in children, paediatricians and intensivists who provide care for children must be prepared to provide optimal respiratory support without putting themselves or other medical, nursing, and paramedical staff at undue risk. We propose an airway management approach that is especially relevant in the current COVID-19 pandemic and provides instructions for: (1) Elective intubation for respiratory failure; and (2) Emergency intubation during cardiopulmonary resuscitation. To minimise risk, intubation methods must be kept as straightforward as possible and should include the provision of appropriate personal protection and equipment to healthcare workers. We identify two key considerations: that bag-mask ventilation should be avoided if possible and that bacterial and viral filters should be placed in the respiratory circuit. Our novel approach provides a framework for airway management that could benefit paediatric critical care practitioners who provide care for any children with a novel viral illness, with a focus on infection prevention during high-risk airway management procedures.


Subject(s)
COVID-19 , Respiratory Insufficiency , Airway Management/methods , Child , Humans , Pandemics/prevention & control , SARS-CoV-2
4.
Can J Anaesth ; 67(11): 1576-1594, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32770311

ABSTRACT

This narrative review critically evaluates the evidence for risk of anemia and red blood cell (RBC) transfusion. For this purpose, it assesses large prospective randomized-controlled trials (RCTs) in medical, surgical, and critical care patient populations in which the impact of specific hemoglobin transfusion thresholds are compared. In these trials, the risks of anemia relative to those of RBC transfusion are assessed. The results of published systematic reviews and meta-analyses are also discussed. Lastly, recommendations for patient blood management and treatment of anemia are explored. The main conclusion of this review emphasizes that the decision to transfuse RBCs is complex and depends on the interaction between multiple factors including the balance between the risk of anemia and the risk of RBC transfusion, existing patient comorbidities, and medical and surgical exposures. The transfusion thresholds recommended by current guidelines vary for medical and surgical patient populations. Guidelines suggesting specific transfusion thresholds for different patient populations should be viewed as a starting point for making an informed decision about RBC transfusion. Alternatives to transfusion (i.e., patient blood management), biomarkers of anemia-induced tissue hypoxia, and transfusion alternatives should continue to be evaluated in large RCTs, with the goal of improving event-free survival in critically ill and perioperative patients.


RéSUMé: Ce compte rendu narratif évalue de façon critique les données probantes concernant le risque de l'anémie et de la transfusion d'érythrocytes. Pour ce faire, nous avons évalué des études randomisées contrôlées (ERC) prospectives de grande envergure réalisées auprès de populations de patients médicaux, chirurgicaux et de soins intensifs dans lesquelles l'impact de seuils spécifiques de transfusion d'hémoglobine est comparé. Dans ces études, les risques de l'anémie sont comparés aux risques de la transfusion d'érythrocytes. Les résultats des comptes rendus systématiques et méta-analyses publiés sont également présentés. Enfin, les recommandations concernant la gestion du sang des patients et le traitement de l'anémie sont explorées. La conclusion principale de ce compte rendu souligne que la décision de transfuser des érythrocytes est complexe et dépend de l'interaction de plusieurs facteurs, notamment de l'équilibre entre le risque de l'anémie et le risque de la transfusion d'érythrocytes, les comorbidités existantes du patient, et les risques médicaux et chirurgicaux. Les seuils de transfusion recommandés par les directives actuelles sont différents pour les populations de patients médicaux et chirurgicaux. Les directives proposant des seuils de transfusion spécifiques en fonction des différentes populations de patients devraient être considérées comme point de départ pour prendre une décision informée concernant la transfusion d'érythrocytes. Les alternatives à la transfusion (c.-à-d. la gestion du sang des patients), les biomarqueurs d'une hypoxie tissulaire induite par l'anémie et les alternatives à la transfusion devraient continuer à être évalués dans des ERC d'envergure, avec pour but l'amélioration de la survie sans complication des patients en état critique et périopératoires.


Subject(s)
Anemia , Erythrocyte Transfusion , Anemia/epidemiology , Anemia/therapy , Blood Transfusion , Critical Care , Critical Illness , Erythrocyte Transfusion/adverse effects , Hemoglobins/analysis , Humans
5.
Hippocampus ; 28(2): 81-96, 2018 02.
Article in English | MEDLINE | ID: mdl-29072798

ABSTRACT

For the sake of rigorous control of task variables, hippocampal place cells have been usually studied in relatively simple environments. To approach the situation of real-life navigation in an urban-like environment, we recorded CA1 place cells while rats performance a memory task in a "Townmaze" with two start locations, three alternate paths in the maze midsection, followed by a two-way choice that determined the trial outcome, access to a goal compartment. Further, to test the ability of place cells to update their spatial representation upon local changes in the environment while maintaining the integrity of the overall spatial map to allow effective navigation, we occasionally introduced barriers in the maze mid-section to force the rat to select a nonpreferred route. The "Townmaze" revealed many new interesting features of CA1 neurons. First, we found neurons with 3-5 fields that appear to represent segments on a single common route through the maze. Second, we found neurons with 3-5 fields similarly aligned along the longitudinal or transverse maze axis. Responses to the barriers were assessed separately near and far from the barriers. Appearance of new fields in response to the barriers took place almost exclusively only locally near the barrier, whereas in-field firing rate changes occurred throughout the maze. Further, field location changes did not correlate with the task performance, whereas firing rate changes did. These findings suggest that in a complex environment with blocked distal views, CA1 neurons code for the environment as sequences of significant nodes but are also capable of extracting and associating common elements across these sequences.


Subject(s)
CA1 Region, Hippocampal/physiology , Choice Behavior/physiology , Maze Learning/physiology , Neurons/physiology , Spatial Behavior/physiology , Action Potentials/physiology , Animals , CA1 Region, Hippocampal/cytology , Environment , Male , Rats , Rats, Long-Evans , Space Perception/physiology
6.
Phys Rev Lett ; 118(17): 175001, 2017 Apr 28.
Article in English | MEDLINE | ID: mdl-28498701

ABSTRACT

Transport barrier formation and its relation to sheared flows in fluids and plasmas are of fundamental interest in various natural and laboratory observations and of critical importance in achieving an economical energy production in a magnetic fusion device. Here we report the first observation of an edge transport barrier formation event in an electrostatic gyrokinetic simulation carried out in a realistic diverted tokamak edge geometry under strong forcing by a high rate of heat deposition. The results show that turbulent Reynolds-stress-driven sheared E×B flows act in concert with neoclassical orbit loss to quench turbulent transport and form a transport barrier just inside the last closed magnetic flux surface.

8.
Climacteric ; 19(1): 85-90, 2016.
Article in English | MEDLINE | ID: mdl-26624862

ABSTRACT

OBJECTIVE: In this study, we aimed to explore the association between polymorphisms in the period (PER) gene and bone response to hormone therapy (HT) in postmenopausal Korean women. METHODS: The PER1 c.2284C > G, c.2247C > T, PER2 c.3731G > A, PER3 c.2592G > A, c.3083T > C polymorphisms, and PER3 54bp variable number of tandem repeats (VNTR) were analyzed in 509 postmenopausal Korean women who received HT. Bone mineral density (BMD) at the lumbar spine and femoral neck before and after 1 year of HT and serum levels of osteoprotegerin (OPG), soluble receptor activator of the nuclear factor-κB ligand (sRANKL) and bone turnover markers were measured after 6 months of HT. RESULTS: The PER1 c.2884 C > G polymorphism and PER3 54bp VNTR were associated with annual percent changes in BMD of the femoral neck after 1 year of HT (p < 0.05). Changes in BMD at the femoral neck in the non-CC genotype of the PER1 c.2884C > G polymorphism and in the 4-repeat homozygote of PER3 54bp VNTR were significantly lower than those in CC genotype and non-4-repeat homozygote, respectively. The PER1 c.2884C > G polymorphism was associated with the non-response (>3% BMD loss/year after HT) of HT. The non-CC genotype of the PER1 c.2884C > G polymorphism showed a 1.92-times higher risk of non-response at the lumbar spine and/or femoral neck (p = 0.01) compared with the CC genotype. No significant changes in bone markers after 6 months of HT were noted according to the PER1 c.2884C > G polymorphism. CONCLUSIONS: The PER1 c.2884C > G polymorphism may be associated with risk of non-response to HT in postmenopausal Korean women.


Subject(s)
Bone Density/genetics , Estrogen Replacement Therapy , Osteoporosis, Postmenopausal/genetics , Period Circadian Proteins/genetics , Estrogens, Conjugated (USP)/administration & dosage , Female , Femur Neck , Genotype , Humans , Lumbar Vertebrae , Medroxyprogesterone/administration & dosage , Middle Aged , Osteoporosis, Postmenopausal/drug therapy , Osteoprotegerin/blood , Polymorphism, Genetic , Postmenopause , RANK Ligand/blood , Republic of Korea
9.
Infection ; 42(2): 343-50, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24277597

ABSTRACT

PURPOSE: Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infection in young children. However, there are limited data on severe RSV infection requiring pediatric intensive care unit (PICU) admission. This retrospective study described features of RSV-associated PICU admissions in Hong Kong and investigated factors for mortality and duration of PICU stay. METHODS: Children with laboratory-confirmed RSV infection and admitted to the PICUs of all eight government hospitals in Hong Kong between January 2009 and June 2011 were identified from computerized auditing systems and PICU databases. RSV in respiratory samples was detected by direct immunofluorescence and/or viral culture. The relationships between mortality and PICU duration and demographic and clinical factors were analyzed. RESULTS: A total of 118 (2.4 %) PICU admissions were identified among 4,912 RSV-positive pediatric cases in all hospitals. Sixty-five (55.6 %) patients were infants. PICU admissions were higher between October and March. Eight (6.8 %) patients died, but only two were infants. RSV-associated mortality was related to prior sick contact, presence of older siblings, neurodevelopmental conditions, chromosomal and genetic diseases, and bacterial co-infections, but none was significant following logistic regression analyses (odds ratio 9.36, 95 % confidence interval 0.91-96.03 for prior sick contact, p = 0.060). Chronic lung disease was the only risk factor for the duration of PICU admission (ß = 0.218, p = 0.017). CONCLUSIONS: The majority of RSV-infected children do not require PICU support. There is winter seasonality for RSV-associated PICU admission in Hong Kong. Prior sick contact is the only risk factor for RSV-associated mortality, whereas the presence of chronic lung disease is associated with longer PICU stay. The current risk-based approach of RSV prophylaxis may not be effective in reducing severe RSV infections.


Subject(s)
Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Viruses/isolation & purification , Respiratory Tract Infections/epidemiology , Child, Preschool , Female , Hong Kong/epidemiology , Hospitalization , Humans , Infant , Intensive Care Units, Pediatric , Male , Respiratory Syncytial Virus Infections/microbiology , Respiratory Syncytial Virus Infections/mortality , Respiratory Tract Infections/microbiology , Respiratory Tract Infections/mortality , Retrospective Studies , Risk Factors
10.
Climacteric ; 17(5): 605-12, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24678593

ABSTRACT

OBJECTIVE: In the present study, we aimed to investigate the association between genetic polymorphisms in period (PER) genes and bone mineral density (BMD) in postmenopausal Korean women. METHODS: The PER1 c.2247C> T and c.2884C> G polymorphisms; the PER2 c.661G> A and c.3731G> A polymorphisms; the PER3 c.2592G> A, c.3029C> T, c.3035C> T, and c.3083T> C polymorphisms, and the 54 bp variable number tandem repeats polymorphism were analyzed in 551 postmenopausal Korean women. Serum leptin, soluble leptin receptor, osteoprotegerin, soluble receptor activator of the nuclear factor-κB ligand, and bone markers including bone alkaline phosphatase and carboxy-terminal telopeptide of type I collagen were measured, and the lumbar spine and femoral neck BMDs were also determined. RESULTS: The PER2 c.661G> A, PER3 c.3029C> T and c.3035C> T polymorphisms were not observed. The PER2 and PER3 polymorphisms evaluated were not related to BMD, whereas associations of the c.2247C> T and c.2884C> G polymorphisms in PER1 with the lumbar spine BMD were observed both singly and in combination. The CC haplotype homozygotes showed significantly lower lumbar spine BMD than participants with other genotypes. Additionally, 2.01-fold higher odds for osteoporosis of the lumbar spine were found in the CC haplotype homozygotes compared to women not carrying the haplotype CC allele. No significant differences in bone markers were detected according to the PER1 haplotype genotype. CONCLUSIONS: Our results suggest that both the PER1 c.2247C> T and c.2884C> G polymorphisms may be genetic factors affecting the lumbar spine BMD in postmenopausal Korean women.


Subject(s)
Bone Density/genetics , Period Circadian Proteins/genetics , Postmenopause/genetics , Aged , Alkaline Phosphatase/blood , Asian People/genetics , Collagen Type I/blood , Female , Femur Neck , Genotype , Haplotypes , Humans , Leptin/blood , Lumbar Vertebrae , Middle Aged , Osteoporosis, Postmenopausal/genetics , Osteoprotegerin/blood , Peptides/blood , Polymorphism, Genetic , Receptors, Leptin/blood
11.
Nano Lett ; 13(12): 5797-802, 2013.
Article in English | MEDLINE | ID: mdl-24228733

ABSTRACT

The recent focus on topological insulators is due to the scientific interest in the new state of quantum matter as well as the technology potential for a new generation of THz optoelectronics, spintronics and quantum computations. It is important to elucidate the dynamics of the Dirac fermions in the topologically protected surface state. Hence we utilized a novel ultrafast optical pump mid-infrared probe to explore the dynamics of Dirac fermions near the Dirac point. The femtosecond snapshots of the relaxation process were revealed by the ultrafast optics. Specifically, the Dirac fermion-phonon coupling strength in the Dirac cone was found to increase from 0.08 to 0.19 while Dirac fermions were away from the Dirac point into higher energy states. Further, the energy-resolved transient reflectivity spectra disclosed the energy loss rate of Dirac fermions at room temperature was about 1 meV/ps. These results are crucial to the design of Dirac fermion devices.


Subject(s)
Nanostructures/chemistry , Nanotechnology , Optics and Photonics , Quantum Theory , Semiconductors , Spectrophotometry, Infrared
12.
Opt Express ; 21(12): 13930-7, 2013 Jun 17.
Article in English | MEDLINE | ID: mdl-23787582

ABSTRACT

This study systematically investigates the influence of free carriers on the generation of THz in ZnTe crystals, over a wide range of pumping fluences. As the pumping fluence is increased (< 6.36 mJ/cm(2)), the concentration of free carriers gradually increases and the THz output power is saturated, as clearly demonstrated by the time delay in the THz temporal waveforms, the changes in the THz spectral weight and the red-shift in the PL spectra. For high pumping fluences (> 6.36 mJ/cm(2)), spectacularly, there is a significant quadratic increase in the THz output power when the pumping fluence is increased, as well as at low pumping fluences of < 0.58 mJ/cm(2), because of the saturation of free carriers.


Subject(s)
Tellurium/chemistry , Tellurium/radiation effects , Zinc/chemistry , Zinc/radiation effects , Crystallization , Electron Transport , Materials Testing , Scattering, Radiation , Terahertz Radiation
13.
Hum Reprod ; 28(5): 1354-60, 2013 May.
Article in English | MEDLINE | ID: mdl-23477907

ABSTRACT

STUDY QUESTION: Is a preponderance of small dense low-density lipoprotein-cholesterol (LDL-C) observed in non-obese women with polycystic ovary syndrome (PCOS)? SUMMARY ANSWER: Non-obese Korean women with PCOS have no quantitative or qualitative changes in LDL-C profiles. WHAT IS KNOWN ALREADY: Small dense LDL particles (sd-LDL) are more atherogenic than large buoyant ones and are strongly associated with coronary artery disease independent of other risk factors. Many investigators have found an increased proportion of atherogenic sd-LDL or a decreased mean LDL particle size in women with PCOS, but all of these studies have been based primarily on obese or overweight women with PCOS. STUDY DESIGN, SIZE, DURATION: This was a case-control study evaluating complete lipid and lipoprotein profiles in 64 PCOS patients and 64 age- and BMI-matched controls. All women with PCOS in our study population were not obese. To determine the differences in the LDL particle profiles between PCOS phenotypes, the patients with PCOS were divided into two subgroups according to the presence of clinical or biochemical hyperandrogenism. PARTICIPANTS/MATERIALS, SETTING, METHODS: Using the Rotterdam criteria, we recruited 64 women (18-40 years) with PCOS who were attending a tertiary university hospital. A total of 64 premenopausal control women were matched with patients based on exact age and BMI (± 1.0 kg/m(2)). All the participants fell within the non-obese range of the BMI (<25 kg/m(2)) according to the definition of obesity for Asians. The LDL subfraction was analyzed by 3% polyacrylamide gel tube electrophoresis. Seven LDL subclasses were quantified and LDL subclasses 3-7 were small LDL subfractions. LDL subfraction scores were calculated based on the following weighted scoring system developed by the manufacturer: scores of <5.5 were categorized as phenotype A (large, buoyant LDLs), and those >5.5 were categorized as non-A phenotype (sd-LDLs). The system also determined the mean LDL particle size diameter. MAIN RESULTS AND THE ROLE OF CHANCE: There were no differences in the absolute level of LDL-C, mean LDL diameter or percentage of atherogenic sd-LDLs between PCOS patients and controls or between hyperandrogenic and non-hyperandrogenic PCOS subgroups. Also, none of the subjects showed a non-A LDL phenotype. The most notable finding of our study was the difference in the lipoprotein (a) levels and prevalence of its elevation in PCOS patients versus controls (P = 0.002 and P = 0.004, respectively), and between PCOS subgroups (P = 0.030 and P = 0.047, respectively). LIMITATIONS, REASONS FOR CAUTION: Inclusion of only non-obese subjects, small sample size and lack of information on other potential confounding factors, such as differences in diet and/or exercise patterns. WIDER IMPLICATIONS OF THE FINDINGS: Although our findings suggest that non-obese women with PCOS have no significant quantitative or qualitative changes in LDL-C profile, data on obese Korean women with PCOS could offer complementary findings about the possible relationship between the magnitude of obesity and LDL phenotype. Further investigations are needed to determine whether a change in lipoprotein (a) in non-obese women with PCOS is also found in other ethnic groups. STUDY FUNDING/COMPETING INTEREST(S): No conflict of interest exists. This study was supported by a grant of the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (A100624). TRIAL REGISTRATION NUMBER: N/A.


Subject(s)
Atherosclerosis/blood , Cholesterol, LDL/blood , Dyslipidemias/blood , Dyslipidemias/complications , Polycystic Ovary Syndrome/blood , Polycystic Ovary Syndrome/complications , Adolescent , Adult , Body Mass Index , Body Weight , Case-Control Studies , Female , Humans , Insulin Resistance , Particle Size , Phenotype , Republic of Korea , Young Adult
14.
J Periodontal Res ; 47(6): 800-10, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22780690

ABSTRACT

BACKGROUND AND OBJECTIVE: Polycan is a promising candidate for the treatment of periodontal disease. This study was undertaken to examine whether Polycan, a type of ß-glucan, has a protective effect on ligature-induced experimental periodontitis and related alveolar bone loss in Sprague-Dawley rats. MATERIAL AND METHODS: Polycan was orally administered, daily, for 10 d, at 21.25, 42.5 or 85 mg/kg, beginning 1 d after ligation. Changes in body weight and alveolar bone loss were monitored, and the anti-inflammatory effects of Polycan were determined by measuring the levels of myeloperoxidase (MPO), interleukin-1beta (IL-1ß) and tumor necrosis factor-alpha (TNF-α) in gingival tissue. We also evaluated inducible nitric oxide synthase (iNOS) activity and malondialdehyde (MDA) concentrations as a measure of the antioxidant effect. RESULTS: Ligature placement led to a marked decrease in body weight, increased alveolar bone loss and increased concentrations of MPO, IL-1ß, TNF-α and MDA, as well as increased iNOS activity and inflammatory cell infiltration and decreased collagen-fiber content. Histological examination revealed increases in the number and activity of osteoclast cells, decreases in alveolar bone volume and elevated percentages of osteclasts on the alveolar bone surface. Daily oral treatment with 42.5 or 85 mg/kg of Polycan for 10 d led to significant, dose-dependent inhibition of the effect of ligature placement. CONCLUSION: Taken together, these results suggest that 10 d of oral treatment with Polycan effectively inhibits ligature placement-induced periodontitis and related alveolar bone loss via an antioxidant effect.


Subject(s)
Alveolar Bone Loss/prevention & control , Antioxidants/therapeutic use , Periodontitis/drug therapy , beta-Glucans/therapeutic use , Animals , Antioxidants/pharmacology , Body Weight/drug effects , Gingiva/metabolism , Interleukin-1beta/analysis , Lipid Peroxidation , Male , Malondialdehyde/analysis , Nitric Oxide Synthase Type II/metabolism , Oxidative Stress/drug effects , Peroxidase/metabolism , Rats , Rats, Sprague-Dawley , Tumor Necrosis Factor-alpha/analysis , beta-Glucans/pharmacology
15.
Climacteric ; 14(4): 488-91, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21413863

ABSTRACT

OBJECTIVE: We aimed to analyze the association between hormone therapy (HT) and nerve conduction parameters. METHODS: This retrospective study consisted of 46 postmenopausal women not receiving HT, and 18 postmenopausal women who received HT. Eligible patients were identified from the hospital's database and the nerve conduction study was performed on the upper or lower limb without pain or other symptoms. RESULTS: No significant difference was demonstrated in the unadjusted nerve conduction parameters according to HT. After adjusting for age and body mass index, the latency of the posterior tibial motor nerve in postmenopausal women receiving HT was significantly shorter than that in women not receiving HT. Moreover, the velocity of the median motor nerve tended to be faster in postmenopausal women receiving HT than those not receiving HT, although the difference was not statistically significant. CONCLUSION: These findings imply that HT may affect the nerve conduction parameters in postmenopausal women.


Subject(s)
Estrogen Replacement Therapy , Neural Conduction/physiology , Postmenopause/physiology , Estradiol/blood , Female , Humans , Middle Aged , Neural Conduction/drug effects , Peripheral Nerves/drug effects , Peripheral Nerves/physiology , Retrospective Studies
16.
Climacteric ; 14(1): 66-74, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20649504

ABSTRACT

OBJECTIVE: We sought to assess the prevalence of metabolic syndrome (MetS) among Korean postmenopausal women and to investigate the effect of hormone therapy status and reproductive characteristics on body composition and MetS risk factors. STUDY DESIGN: We performed a cross-sectional study involving a cohort of 2005 postmenopausal Korean women. We defined MetS using the modified National Cholesterol Education Program (NCEP) criteria proposed by the American Heart Association/National Heart, Lung, and Blood Institute guidelines. The criteria for abdominal obesity were adopted from the cut-offs suggested by the Korean Society for the Study of Obesity. Participants with three or more of the following conditions were classified as having MetS: waist circumference ≥ 85 cm; blood pressure ≥ 130/85 mmHg; fasting plasma triglycerides ≥ 150 mg/dl; high density lipoprotein cholesterol < 50 mg/dl; glucose ≥ 100 mg/dl and/or receiving treatment for their condition. RESULTS: The prevalence of MetS was 22.1% in the study population and increased with age. After adjusting for age and related reproductive characteristics, it was found that ever-use of hormone therapy (prior or current) was associated with decreased risk of postmenopausal MetS. Among individual risk factors for MetS, current hormone therapy seemed to be associated with decreased prevalence of abdominal obesity and better glucose metabolism and prior use of hormone therapy were associated with lower risk of abdominal obesity and high blood pressure. CONCLUSION: Postmenopausal hormone therapy is associated with decreased risk of MetS in postmenopausal Korean women.


Subject(s)
Hormone Replacement Therapy , Metabolic Syndrome/epidemiology , Age Factors , Aged , Aged, 80 and over , Blood Glucose/metabolism , Body Fat Distribution , Body Mass Index , C-Reactive Protein/analysis , Cholesterol/blood , Cohort Studies , Cross-Sectional Studies , Female , Humans , Hypertension/epidemiology , Middle Aged , Obesity, Abdominal/epidemiology , Postmenopause , Prevalence , Republic of Korea/epidemiology , Risk Factors , Triglycerides/blood , Waist Circumference
17.
Acta Anaesthesiol Scand ; 55(9): 1124-31, 2011 Oct.
Article in English | MEDLINE | ID: mdl-22092211

ABSTRACT

BACKGROUND: Cardiac progenitor cells (CPCs) derived from human embryonic stem cells (hESCs) can multiply and generate cardiomyocytes, offering their tremendous potential for cardiac regenerative therapy. However, poor survival under stressful conditions is a major hurdle in the regeneration. We investigated whether isoflurane-induced preconditioning can increase hESC-derived CPC survival under oxidative stress. METHODS: Undifferentiated hESCs were cultured in suspension with 20% FBS (fetal bovine serum) and 20 ng/ml of BMP-4 (bone morphogenetic protein-4) to form embryoid bodies and grown onto Matrigel-coated plates for 2-3 weeks. To characterise the differentiated CPCs, immunostaining for Nkx2.5 (nonspecific transcriptional marker) and Isl-1 was performed. hESC-derived CPCs were exposed to oxidative stress induced by H(2) O(2) and FeSO(4) . For anaesthetic preconditioning, CPCs were exposed to isoflurane (0.25, 0.5, 1.0 mM). CPC survival was determined by trypan blue exclusion. A mitoK(ATP) channels inhibitor, 5-hydroxydecanoic acid (200 µM) and an opener, diazoxide (100 µM), were used to investigate the involvement of mitoK(ATP) channels. RESULTS: hESC-derived CPCs stained with Nkx2.5 were 95 ± 3% of total cell number. Isoflurane (0.5 and 1.0 mM)-preconditioned CPCs showed a significantly lower death rate compared with control (0.5 mM: 30.6 ± 10.7% and 1.0 mM: 28.5 ± 6.2% vs. control: 43.2 ± 9.9%). Inhibition of mitoK(ATP) channels with 5-HD completely abolished the protective effects of isoflurane. Diazoxide significantly decreased CPC death (29.5 ± 12.4%). However, when diazoxide was applied to CPC preconditioned with isoflurane, CPC death did not decrease further (28.7 ± 10.9%). CONCLUSION: Isoflurane increased hESC-derived Nkx2.5(+) CPC survival under oxidative stress, and mitoK(ATP) channels may be involved in the protective effect.


Subject(s)
Anesthetics, Inhalation/pharmacology , Embryonic Stem Cells/cytology , Homeodomain Proteins/analysis , Isoflurane/pharmacology , Myocytes, Cardiac/drug effects , Stem Cells/drug effects , Transcription Factors/analysis , Cell Differentiation/drug effects , Cell Survival/drug effects , Decanoic Acids/pharmacology , Diazoxide/pharmacology , Homeobox Protein Nkx-2.5 , Humans , Hydroxy Acids/pharmacology , Myocytes, Cardiac/cytology , Oxidative Stress , Potassium Channels/drug effects , Stem Cells/physiology
18.
Infection ; 38(5): 373-9, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20661622

ABSTRACT

BACKGROUND: The human immunodeficiency virus (HIV) epidemic and increasing use of immunosuppressive agents have increased the prevalence of both cryptococcosis and tuberculosis (TB). However, the status of co-infection with both pathogens remains unknown. METHODS: This study retrospectively reviewed patient records of cryptococcosis and TB co-infection from 1993 to 2006. The temporal sequence of co-infection was defined as either concurrent or sequential. Data collected included patient demographics, HIV status, co-morbidities, clinical manifestations, treatment strategies, and outcome at 1-year follow-up. RESULTS: There were 23 patients with cryptococcosis and TB co-infection, representing 5.4% of cryptococcosis or 0.6% of TB cases. Eleven (48%) patients were HIV-infected, and no underlying disease or immunocompromised state could be identified in six (26%) patients. Twelve (52%) patients presented with concurrent infection, but diagnosis of co-infection could be achieved simultaneously in only three (13%). Constitutional symptoms, particularly fever and weight loss, were the most common presenting symptoms, developing in more than two-thirds of the patients. The majority (83%) of the patients made a good recovery following dual antifungal and anti-TB therapy. There were three mortalities at the 1-year follow-up, which might be attributable to a delay in diagnosis and treatment of co-infection. The outcomes of HIV-infected and non-HIV-infected patients were not significantly different. CONCLUSIONS: Cryptococcosis and TB co-infection, although rare, develops in both immunocompromised and healthy individuals. Early diagnosis and treatment may improve patient prognosis. There should be a high index of suspicion in order to achieve a timely diagnosis in a TB endemic area.


Subject(s)
Cryptococcosis/epidemiology , Hospitals, University/statistics & numerical data , Tuberculosis/epidemiology , Adult , Aged , Anti-Infective Agents/therapeutic use , Cryptococcosis/drug therapy , Cryptococcosis/etiology , Cryptococcosis/microbiology , Cryptococcus neoformans/isolation & purification , Female , HIV Infections/complications , Humans , Male , Middle Aged , Retrospective Studies , Taiwan , Tuberculosis/drug therapy , Tuberculosis/etiology , Tuberculosis/microbiology
19.
Epidemiol Infect ; 138(7): 1036-43, 2010 Jul.
Article in English | MEDLINE | ID: mdl-19796452

ABSTRACT

A retrospective study of clinical characteristics, outcome and prognostic factors of patients with cryptococcosis was undertaken in intensive care units (ICUs) of a medical centre for the period 2000-2005. Twenty-six patients with Cryptococcus neoformans var. grubii infection were identified (16 males, median age 58 years). The most frequent underlying diseases were liver cirrhosis (38.5%), diabetes mellitus (26.9%) and HIV infection (19.2%). The most frequently identified sites of infection were blood (61.5%), cerebrospinal fluid (38.5%) and airways (34.6%). The mean Acute Physiologic and Chronic Health Evaluation II score at ICU admission was 22.46. The ICU mortality rate in these patients was 73.1% (19/26) and there were a further two mortalities recorded after discharge from ICU, reaching a total mortality rate of 80.8% (21/26). Patients with ICU survival >2 weeks had lower rates of HIV infection (P=0.004), less use of inotropic agents during ICU stay (P<0.001) and lower white blood cell counts (P=0.01). After adjusting for clinical variables in the multivariate Cox regression model, diabetes and cryptococcal infection after ICU admission were independent predictors of good long-term prognosis (P=0.015) and HIV infectious status was associated with poor outcome (P=0.012).


Subject(s)
Cross Infection/diagnosis , Cryptococcosis/diagnosis , Cryptococcus neoformans , Intensive Care Units , Ascites/complications , Ascites/epidemiology , Cross Infection/complications , Cross Infection/epidemiology , Cryptococcosis/complications , Cryptococcosis/epidemiology , Diabetes Complications/epidemiology , Female , HIV Infections/complications , HIV Infections/epidemiology , Heart Diseases/complications , Heart Diseases/epidemiology , Humans , Hypertension/complications , Hypertension/epidemiology , Kidney Diseases/complications , Kidney Diseases/epidemiology , Liver Cirrhosis/complications , Liver Cirrhosis/epidemiology , Lung Diseases/complications , Lung Diseases/epidemiology , Male , Middle Aged , Organ Transplantation , Retrospective Studies , Rheumatic Diseases/complications , Rheumatic Diseases/epidemiology
SELECTION OF CITATIONS
SEARCH DETAIL