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1.
Nature ; 596(7871): 221-226, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34381232

RESUMEN

Research on magnetic confinement of high-temperature plasmas has the ultimate goal of harnessing nuclear fusion for the production of electricity. Although the tokamak1 is the leading toroidal magnetic-confinement concept, it is not without shortcomings and the fusion community has therefore also pursued alternative concepts such as the stellarator. Unlike axisymmetric tokamaks, stellarators possess a three-dimensional (3D) magnetic field geometry. The availability of this additional dimension opens up an extensive configuration space for computational optimization of both the field geometry itself and the current-carrying coils that produce it. Such an optimization was undertaken in designing Wendelstein 7-X (W7-X)2, a large helical-axis advanced stellarator (HELIAS), which began operation in 2015 at Greifswald, Germany. A major drawback of 3D magnetic field geometry, however, is that it introduces a strong temperature dependence into the stellarator's non-turbulent 'neoclassical' energy transport. Indeed, such energy losses will become prohibitive in high-temperature reactor plasmas unless a strong reduction of the geometrical factor associated with this transport can be achieved; such a reduction was therefore a principal goal of the design of W7-X. In spite of the modest heating power currently available, W7-X has already been able to achieve high-temperature plasma conditions during its 2017 and 2018 experimental campaigns, producing record values of the fusion triple product for such stellarator plasmas3,4. The triple product of plasma density, ion temperature and energy confinement time is used in fusion research as a figure of merit, as it must attain a certain threshold value before net-energy-producing operation of a reactor becomes possible1,5. Here we demonstrate that such record values provide evidence for reduced neoclassical energy transport in W7-X, as the plasma profiles that produced these results could not have been obtained in stellarators lacking a comparably high level of neoclassical optimization.

3.
Rhinology ; 58(1): 66-73, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-31680128

RESUMEN

BACKGROUND: Airway inflammation and excessive mucin production are pathophysiological characteristics of airway diseases. Fipronil, a pesticide, is being extensively used in agriculture and veterinary medicine worldwide. However, this compound impairs immune function in non-target organisms. The present study aimed to evaluate the effect of fipronil on pro-inflammatory cytokine and mucus production and signalling pathways in human primary nasal METHODOLOGY: The effect of fipronil on pro-inflammatory cytokine and MUC5AC expression and the signalling pathway of fipronil were investigated using real-time PCR, enzyme immunoassays, immunofluorescence, and immunoblot analysis with specific inhibitors and small interfering RNA. RESULTS: Fipronil treatment increased pro-inflammatory cytokine interleukin (IL)-1beta, IL-6, IL-8, and MUC5AC expression in human primary nasal epithelial cells. It also induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) mitogenactivated protein kinase (MAPK), p38 MAPK, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB). MAPK and NF-kB inhibitor treatment significantly inhibited increases in IL-1beta, IL-6, IL-8, and MUC5AC expression. Ex vivo data confirmed that fipronil-induced MUC5AC expression occurs through ERK1/2, p38, and NF-kB signalling pathways in nasal inferior turbinate tissue. CONCLUSIONS: Fipronil induced pro-inflammatory cytokine IL-1beta, IL-6, IL-8, and MUC5AC expression via ERK1/2 MAPK, p38 MAPK, and NF-kB in human primary nasal epithelial cells.


Asunto(s)
Citocinas/metabolismo , Células Epiteliales/efectos de los fármacos , Mucina 5AC/metabolismo , Pirazoles/farmacología , Células Cultivadas , Células Epiteliales/metabolismo , Humanos , FN-kappa B/metabolismo , Transducción de Señal , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
4.
Phys Rev Lett ; 123(2): 025002, 2019 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-31386539

RESUMEN

For the first time, the optimized stellarator Wendelstein 7-X has operated with an island divertor. An operation regime in hydrogen was found in which the total plasma radiation approached the absorbed heating power without noticeable loss of stored energy. The divertor thermography recorded simultaneously a strong reduction of the heat load on all divertor targets, indicating almost complete power detachment. This operation regime was stably sustained over several energy confinement times until the preprogrammed end of the discharge. The plasma radiation is mainly due to oxygen and is located at the plasma edge. This plasma scenario is reproducible and robust at various heating powers, plasma densities, and gas fueling locations. These experimental results show that the island divertor concept actually works and displays good power dissipation potential, producing a promising exhaust concept for the stellarator reactor line.

5.
Int Endod J ; 52(2): 244-249, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30040121

RESUMEN

AIM: To determine the distortional angle and torsional load at the pseudoelastic limit of Reciproc Blue instruments and to verify the safety of using pre-set dedicated motors designed for use with the original Reciproc instruments. METHODOLOGY: Two torsional conditions of Reciproc R25 and Reciproc Blue R25 were tested using a custom device. The first condition fixed the file tips at 3 mm and repetitively rotated them, with gradually increasing angles, from 10° to 270°, and the resulting torque was recorded (n = 15). The second test involved a single continuous rotation until fracture (n = 15). The pseudoelastic limits of the instruments were determined from their torque-rotation curves. For statistical analysis, two-way analysis of variance and t-tests were used, at a 95% significance level. Tested specimens were examined using field-emission scanning electron microscopy (FE-SEM). RESULTS: The angle at the pseudoelastic limit was significantly greater for Reciproc Blue than Reciproc, regardless of test mode (P < 0.05). When torsional loading was repeated, using gradually increasing rotational angles, the torsional resistance was significantly lower than for a single rotation (P < 0.05). However, under all test conditions, the pseudoelastic limit was below the pre-set 170° of the dedicated reciprocating motor. FE-SEM evaluation of the lateral aspects of the instruments revealed numerous longitudinal microcracks running along their long axis. For Reciproc Blue groups, the file shaft machining grooves were distorted after repetitive and continuous torsional tests. CONCLUSIONS: The 170° pre-set angle of the dedicated endodontic motors for the Reciproc system was safe for Reciproc Blue in single or time-restricted use.


Asunto(s)
Instrumentos Dentales , Diseño de Equipo , Preparación del Conducto Radicular/instrumentación , Torsión Mecánica , Análisis de Varianza , Aleaciones Dentales/química , Falla de Equipo , Análisis de Falla de Equipo , Seguridad de Equipos , Humanos , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Níquel/química , Rotación , Estrés Mecánico , Propiedades de Superficie , Titanio/química , Torque
6.
J Oral Rehabil ; 44(8): 617-625, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28547776

RESUMEN

This study aimed to evaluate the possibility of root fenestration or oroantral communication by evaluating the distance from root apex to the sinus floor and buccal cortex in maxillary posterior teeth using cone-beam computed tomography (CBCT) images. The study included 2182 roots of the maxillary posterior teeth from 219 patients after reviewing CBCT images of 462 patients according to the location of roots by two endodontists. The distances from each root apex to the maxillary sinus floor and buccal and palatal cortices were evaluated according to sex and age, and the mean values were compared by one-way analysis of variance and Mann-Whitney U-test. The distance between root apex and maxillary sinus floor was the greatest in maxillary first premolars and shortest in the mesio-buccal roots of maxillary second molars. The distances from root apex to the buccal and palatal cortical bones were significantly greater in male patients than those in female patients (P < 0·05). The palatal roots of maxillary first molars exhibited the highest incidence as well as the greatest mean length (1·96 mm) of protrusion into the maxillary sinus. The distance from root apex to the sinus floor was found to increase with age, except in case of maxillary second premolars. Understanding the relationship of maxillary posterior teeth with the sinus floor and buccal cortex could provide clinicians valuable information to help reduce iatrogenic damage.


Asunto(s)
Tomografía Computarizada de Haz Cónico , Enfermedad Iatrogénica/prevención & control , Maxilar/anatomía & histología , Seno Maxilar/anatomía & histología , Ápice del Diente/anatomía & histología , Raíz del Diente/anatomía & histología , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Humanos , Masculino , Maxilar/diagnóstico por imagen , Seno Maxilar/diagnóstico por imagen , Persona de Mediana Edad , Tratamiento del Conducto Radicular/efectos adversos , Ápice del Diente/diagnóstico por imagen , Raíz del Diente/diagnóstico por imagen , Adulto Joven
7.
Int Endod J ; 48(7): 666-72, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25088359

RESUMEN

AIM: To examine the effect of several standard geometric characteristics of rotary instruments on the 'screw-in' forces and stresses generated on root dentine using 3D finite element analysis (FEA). METHODOLOGY: Four cross-sectional designs (triangular, slender-rectangular, rectangular and square) were evaluated. The area of the triangular cross-section and of the slender-rectangular model were the same. Another rectangular model had the same centre-core diameter as the triangular one. Each design was twisted into a file model with 5, 10 or 15 threads over its 16-mm-long working section. Three curved root canals were simulated as rigid surface models: θ = 15 degrees/R = 36 mm radius; θ = 30/R = 18; and θ = 45/R = 12. A commercial FEA package was used to simulate the file rotating in the canal to determine the 'screw-in' force and reaction torque on the instrument. RESULTS: Instruments of a square cross-section had the highest 'screw-in' force and reaction torsional stresses followed by the rectangle, the triangle design and the slender-rectangle design, respectively. The file with closer pitch generated lower stresses, compared with that with longer pitch. The greater the root canal curvature, the higher the 'screw-in' force and reaction torque generated. CONCLUSION: This study demonstrated that the 'screw-in' tendency depends on both the instrument geometry and canal curvature. Clinicians should be aware that certain instrument designs are prone to develop high 'screw-in' forces, requiring the operator to maintain control of the handpiece or to use a brushing action to prevent instruments being pulled into the canal.


Asunto(s)
Instrumentos Dentales , Preparación del Conducto Radicular/instrumentación , Aleaciones Dentales , Análisis del Estrés Dental/métodos , Elasticidad , Diseño de Equipo , Análisis de Elementos Finitos , Níquel , Estrés Mecánico , Titanio , Torsión Mecánica
8.
Diabetologia ; 56(4): 696-708, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23344728

RESUMEN

AIMS/HYPOTHESIS: The aim of this work was to compare the glucose-lowering efficacy of dipeptidyl peptidase-4 (DPP-4) inhibitors between Asian and non-Asian patients with type 2 diabetes. METHODS: We searched MEDLINE, EMBASE, LILACS, CENTRAL, ClinicalTrials.gov and conference proceedings. Studies were eligible if they were randomised controlled trials with a treatment duration of at least 12 weeks, compared a DPP-4 inhibitor with a placebo as either monotherapy or oral combination therapy, had information on ethnicity and HbA1c values and were published or described in English. A systematic review and meta-analysis with a meta-regression analysis was conducted. RESULTS: Among 809 potentially relevant studies, 55 trials were included. A meta-analysis revealed that DPP-4 inhibitors lowered HbA1c to a greater extent in studies with ≥50% Asian participants (weighted mean difference [WMD] -0.92%; 95% CI -1.03, -0.82) than in studies with <50% Asian participants (WMD -0.65%; 95% CI -0.69, -0.60). The between-group difference was -0.26% (95% CI -0.36, -0.17, p < 0.001). The baseline BMI significantly correlated with the HbA1c-lowering efficacy of DPP-4 inhibitors. The RR of achieving the goal of HbA1c <7.0% (53.0 mmol/mol) was higher in studies with ≥50% Asian participants (3.4 [95% CI 2.6, 4.7] vs 1.9 [95% CI 1.8, 2.0]). The fasting plasma glucose-lowering efficacy was higher with monotherapy in the Asian-dominant studies, but the postprandial glucose-lowering efficacy and changes in body weight were comparable between the two groups. CONCLUSIONS/INTERPRETATION: DPP-4 inhibitors exhibit a better glucose-lowering efficacy in Asians than in other ethnic groups; this requires further investigation to understand the underlying mechanism, particularly in relation to BMI.


Asunto(s)
Glucemia/efectos de los fármacos , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/etnología , Inhibidores de la Dipeptidil-Peptidasa IV/farmacología , Administración Oral , Pueblo Asiatico , Índice de Masa Corporal , Peso Corporal , Humanos , Periodo Posprandial , Ensayos Clínicos Controlados Aleatorios como Asunto , Análisis de Regresión , Resultado del Tratamiento
9.
Epidemiol Infect ; 141(5): 1070-9, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-22853817

RESUMEN

A total of 245 patients with confirmed 2009 H1N1 influenza were admitted to the intensive-care units of 28 hospitals (South Korea). Their mean age was 55.3 years with 68.6% aged >50 years, and 54.7% male. Nine were obese and three were pregnant. One or more comorbidities were present in 83.7%, and nosocomial acquisition occurred in 14.3%. In total, 107 (43.7%) patients received corticosteroids and 66.1% required mechanical ventilation. Eighty (32.7%) patients died within 30 days after onset of symptoms and 99 (40.4%) within 90 days. Multivariate logistic regression analysis showed that the clinician's decision to prescribe corticosteroids, older age, Sequential Organ Failure Assessment score and nosocomial bacterial pneumonia were independent risk factors for 90-day mortality. In contrast with Western countries, critical illness in Korea in relation to 2009 H1N1 was most common in older patients with chronic comorbidities; nosocomial acquisition occurred occasionally but disease in obese or pregnant patients was uncommon.


Asunto(s)
Subtipo H1N1 del Virus de la Influenza A , Gripe Humana/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antivirales/uso terapéutico , Enfermedad Crítica , Femenino , Humanos , Gripe Humana/tratamiento farmacológico , Gripe Humana/virología , Masculino , Persona de Mediana Edad , República de Corea/epidemiología , Factores de Riesgo , Adulto Joven
10.
Diabetologia ; 55(4): 981-95, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22109280

RESUMEN

AIMS/HYPOTHESIS: FTO harbours the strongest known obesity-susceptibility locus in Europeans. While there is growing evidence for a role for FTO in obesity risk in Asians, its association with type 2 diabetes, independently of BMI, remains inconsistent. To test whether there is an association of the FTO locus with obesity and type 2 diabetes, we conducted a meta-analysis of 32 populations including 96,551 East and South Asians. METHODS: All studies published on the association between FTO-rs9939609 (or proxy [r (2) > 0.98]) and BMI, obesity or type 2 diabetes in East or South Asians were invited. Each study group analysed their data according to a standardised analysis plan. Association with type 2 diabetes was also adjusted for BMI. Random-effects meta-analyses were performed to pool all effect sizes. RESULTS: The FTO-rs9939609 minor allele increased risk of obesity by 1.25-fold/allele (p = 9.0 × 10(-19)), overweight by 1.13-fold/allele (p = 1.0 × 10(-11)) and type 2 diabetes by 1.15-fold/allele (p = 5.5 × 10(-8)). The association with type 2 diabetes was attenuated after adjustment for BMI (OR 1.10-fold/allele, p = 6.6 × 10(-5)). The FTO-rs9939609 minor allele increased BMI by 0.26 kg/m(2) per allele (p = 2.8 × 10(-17)), WHR by 0.003/allele (p = 1.2 × 10(-6)), and body fat percentage by 0.31%/allele (p = 0.0005). Associations were similar using dominant models. While the minor allele is less common in East Asians (12-20%) than South Asians (30-33%), the effect of FTO variation on obesity-related traits and type 2 diabetes was similar in the two populations. CONCLUSIONS/INTERPRETATION: FTO is associated with increased risk of obesity and type 2 diabetes, with effect sizes similar in East and South Asians and similar to those observed in Europeans. Furthermore, FTO is also associated with type 2 diabetes independently of BMI.


Asunto(s)
Pueblo Asiatico/genética , Diabetes Mellitus Tipo 2/genética , Obesidad/genética , Proteínas/genética , Adulto , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato , Femenino , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Polimorfismo de Nucleótido Simple
11.
Cells Tissues Organs ; 194(2-4): 188-93, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21576914

RESUMEN

N-terminal and C-terminal (CT) domains of amelogenin have been shown to be essential for proper enamel formation. Recent studies have also suggested that although the C-terminus plays an apparent role in protein-mineral interactions, other amelogenin structural domains are involved. The objective was to explore the role of the amelogenin N-terminus in the regulation of calcium phosphate formation in vitro. Spontaneous mineralization studies were carried out using the phosphorylated (+P) and nonphosphorylated (-P) N-terminus of the leucine-rich amelogenin peptide (LRAP) that lacks the hydrophilic CT domain. Mineralization progress was monitored via changes in solution pH. Mineral phases formed were characterized using TEM, selected area electron diffraction, and FT-IR. In controls, amorphous calcium phosphate was initially formed and subsequently transformed to randomly oriented hydroxyapatite (HA) plate-like crystals. In contrast to the control, LRAP(+P)-CT stabilized ACP formation for >1 day, while LRAP(-P)-CT accelerated the transformation of ACP to HA but had little effect on crystal shape or orientation. In conclusion, the N-terminal domain found in LRAP, as in amelogenins, appears to have the capacity to interact with forming calcium phosphate mineral phases. Results suggest that the N-terminal domain of amelogenin may play a direct role in early stages of enamel formation.


Asunto(s)
Amelogenina/química , Amelogenina/metabolismo , Fosfatos de Calcio/metabolismo , Amelogenina/ultraestructura , Secuencia de Aminoácidos , Animales , Calcificación Fisiológica/fisiología , Proteínas del Esmalte Dental/química , Proteínas del Esmalte Dental/ultraestructura , Concentración de Iones de Hidrógeno , Datos de Secuencia Molecular , Espectroscopía Infrarroja por Transformada de Fourier , Relación Estructura-Actividad , Sus scrofa , Factores de Tiempo
12.
Folia Morphol (Warsz) ; 80(4): 963-971, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-32896868

RESUMEN

BACKGROUND: The aim of this study was to clarify the morphologic and morphometric characteristics of the adductor minimus (AMi) and to observe its topographic relationships relative to the adjacent anatomical structures. MATERIALS AND METHODS: This study investigated 54 thighs of 27 Korean cadavers. RESULTS: The AMi was a small and flat muscle observed in 94.4% of the specimens. It originated from the inferior ramus of the pubis as the upper part of the adductor magnus (AMa), and inserted from the lesser trochanter to the upper part of the linea aspera. The AMi was completely separate from the AMa in 63.0% of the specimens. The medial circumflex femoral artery was always found at the superior border of the AMi, while the first and second perforating arteries were found inferior to the muscle in 55.6% and 37.0% of specimens, respectively. A supernumerary muscle was found with the AMi in 42.6% of the specimens, and it originated from the inferior ramus of the pubis and inserted into the posterior side of the lesser trochanter. The obturator externus and AMi were found superoposterior and inferior to the supernumerary muscle, respectively, while the posterior branch of the obturator nerve passed underneath it. CONCLUSIONS: The results of this study may provide physicians with the accurate anatomical knowledge that they require for managing groin pain and applying a regional nerve block with ultrasound guidance in this adductor region.


Asunto(s)
Nervio Obturador , Muslo , Cadáver , Humanos , Músculo Esquelético , Nervio Obturador/anatomía & histología , República de Corea
13.
Rev Sci Instrum ; 92(3): 033531, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33820062

RESUMEN

We present a framework for training artificial neural networks (ANNs) as surrogate Bayesian models for the inference of plasma parameters from diagnostic data collected at nuclear fusion experiments, with the purpose of providing a fast approximation of conventional Bayesian inference. Because of the complexity of the models involved, conventional Bayesian inference can require tens of minutes for analyzing one single measurement, while hundreds of thousands can be collected during a single plasma discharge. The ANN surrogates can reduce the analysis time down to tens/hundreds of microseconds per single measurement. The core idea is to generate the training data by sampling them from the joint probability distribution of the parameters and observations of the original Bayesian model. The network can be trained to learn the reconstruction of plasma parameters from observations and the model joint probability distribution from plasma parameters and observations. Previous work has validated the application of such a framework to the former case at the Wendelstein 7-X and Joint European Torus experiments. Here, we first give a description of the general methodological principles allowing us to generate the training data, and then we show an example application of the reconstruction of the joint probability distribution of an effective ion charge Zeff-bremsstrahlung model from data collected at the latest W7-X experimental campaign. One key feature of such an approach is that the network is trained exclusively on data generated with the Bayesian model, requiring no experimental data. This allows us to replicate the training scheme and generate fast, surrogate ANNs for any validated Bayesian diagnostic model.

14.
J Hosp Infect ; 117: 28-36, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34453983

RESUMEN

BACKGROUND: There is growing evidence that super-spreading events (SSEs) and multiple-spreading events (MSEs) are a characteristic feature of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, data regarding the possibility of SSEs or MSEs in healthcare settings are limited. METHODS: This study was performed at a tertiary-care hospital in Korea. We analysed the nosocomial COVID-19 cases that occurred in healthcare workers and inpatients and their caregivers between January and 20th December 2020. Cases with two to four secondary cases were defined as MSEs and those with five or more secondary cases as SSEs. FINDINGS: We identified 21 nosocomial events (single-case events, N = 12 (57%); MSE + SSE, N = 9 (43%)) involving 65 individuals with COVID-19. Of these 65 individuals, 21 (32%) were infectors. The infectors tended to have a longer duration between symptom onset and diagnostic confirmation than did the non-infectors (median two days vs zero days, P=0.08). Importantly, 12 (18%) individuals were responsible for MSEs and one (2%) for an SSE, which collectively generated 35 (54%) secondary cases. CONCLUSION: In a hospital with thorough infection-control measures, approximately 70% of the nosocomial cases of COVID-19 did not generate secondary cases, and one-fifth of the infectors were responsible for SSEs and MSEs, which accounted for approximately half of the total cases. Early case identification, isolation, and extensive contact tracing are important for the prevention of transmission and SSEs.


Asunto(s)
COVID-19 , Infección Hospitalaria , Análisis por Conglomerados , Trazado de Contacto , Infección Hospitalaria/epidemiología , Humanos , SARS-CoV-2
15.
Br J Anaesth ; 105(6): 753-9, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20923869

RESUMEN

BACKGROUND: We determined cardiovascular responses to tracheal intubation in relation to the time since injury in patients with different levels of spinal cord injury. METHODS: Two hundred and fourteen patients with complete cord injury were studied. They were either quadriplegics (>C7, n=71) or paraplegics (20 yr. Twenty patients with no cord injury served as controls. Systolic arterial pressure (SAP), heart rate (HR), and plasma catecholamine concentrations were determined. RESULTS: Intubation did not affect SAP in the quadriplegics regardless of the time post-injury, but it significantly increased SAP in all paraplegics. Moreover, the pressor response was enhanced in the paraplegics who were 10 yr or more since injury (P<0.05). HR increased significantly in all groups; the magnitude of the increase was less only in acute quadriplegics compared with controls. Plasma concentrations of norepinephrine increased in every group except for the quadriplegics within 4 weeks of injury. The maximum increases in SAP, HR, and norepinephrine from awake baseline values were smaller in the quadriplegics than in the paraplegics (P<0.01). CONCLUSIONS: The cardiovascular and catecholamine responses to intubation change as a function of the time elapsed and the level of the cord injury. In this study, the pressor response to tracheal intubation was abolished in the quadriplegics but not in paraplegics; indeed, it was enhanced at 10 yr or more since injury in this group.


Asunto(s)
Presión Sanguínea/fisiología , Frecuencia Cardíaca/fisiología , Intubación Intratraqueal , Traumatismos de la Médula Espinal/fisiopatología , Adulto , Anciano , Anestesia General , Arritmias Cardíacas/etiología , Epinefrina/sangre , Femenino , Humanos , Hipertensión/etiología , Complicaciones Intraoperatorias , Intubación Intratraqueal/efectos adversos , Laringoscopía , Masculino , Persona de Mediana Edad , Norepinefrina/sangre , Paraplejía/etiología , Paraplejía/fisiopatología , Cuadriplejía/etiología , Cuadriplejía/fisiopatología , Traumatismos de la Médula Espinal/complicaciones , Factores de Tiempo , Adulto Joven
16.
Bioessays ; 30(11-12): 1185-92, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18937367

RESUMEN

Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disorder of motor neurones. Although the genetic basis of familial forms of ALS has been well explored, the molecular basis of sporadic ALS is less well understood. Recent evidence has linked sporadic ALS with the failure to edit key residues in ionotropic glutamate receptors, resulting in excessive influx of calcium ions into motor neurones which in turn triggers cell death. Here we suggest that edited AMPA glutamate (GluR2) receptor subunits serve as gatekeepers for motor neurone survival.


Asunto(s)
Esclerosis Amiotrófica Lateral/metabolismo , Neuronas Motoras/fisiología , Receptores AMPA/metabolismo , Animales , Calcio/metabolismo , Humanos , Iones , Modelos Biológicos , Neuronas/metabolismo , Permeabilidad , Biosíntesis de Proteínas , Edición de ARN , Transcripción Genética
17.
J Hosp Infect ; 104(4): 476-483, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31785319

RESUMEN

BACKGROUND: Concerns are growing over the importance of the hospital water environment for the transmission of carbapenemase-producing Enterobacteriaceae (CPE). AIM: To report a large outbreak in the cardiology units involving intensive care units (ICUs) and wards at a tertiary-care hospital. METHODS: This was a contact tracing, case-control study to find the risk factors for acquisition of CPE and environmental sampling was performed during a CPE outbreak between July and December 2018. FINDINGS: A total of 87 patients with CPE infection or colonization were identified in the cardiology units of the Asan Medical Centre. Diverse organisms were identified containing blakpc, blaNDM-1, blaVIM or blaIMP, blaOXA-48, and co-producing organisms. A case-control study indicated that using the sinks in the ward patient room bathroom for teeth brushing was associated with CPE acquisition (83% vs 30%; P=0.03). The environment was cultured and Klebsiella pneumoniae carbapenemase (KPC)-producing Escherichia coli was isolated from a water dispenser and New Delhi metallo-beta-lactamase (NDM) 1-producing Citrobacter freundii and Enterobacter cloacae from sinks in patient rooms. Pulsed-field gel electrophoresis (PFGE) analysis of KPC-producing E. coli from patients and the water dispenser in ICU and NDM-1-producing E. cloacae from the patient and sink drain showed the same pulsotypes. CONCLUSIONS: The water dispenser and sink drain were suspected as possible reservoirs of CPE in this outbreak. Close contacts with contaminated water such as tooth brushing were identified as risk factors for CPE acquisition. Education for the adequate use of the water environment system as well as the control of the hospital water environment should be implemented to prevent the CPE outbreaks.


Asunto(s)
Enterobacteriaceae Resistentes a los Carbapenémicos/aislamiento & purificación , Infecciones por Enterobacteriaceae/etiología , Infecciones por Enterobacteriaceae/microbiología , Contaminación de Equipos , Microbiología del Agua , Anciano , Enterobacteriaceae Resistentes a los Carbapenémicos/genética , Cardiología , Estudios de Casos y Controles , Brotes de Enfermedades , Enterobacteriaceae , Femenino , Unidades Hospitalarias , Hospitales , Humanos , Masculino , Persona de Mediana Edad , República de Corea/epidemiología , Factores de Riesgo , Encuestas y Cuestionarios
18.
J Dent Res ; 98(4): 468-475, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30744480

RESUMEN

The present study was conducted to investigate the role of proteolysis by matrix metalloproteinase 20 (MMP20) in regulating the initial formation of the enamel mineral structure during the secretory stage of amelogenesis, utilizing Mmp20-null mice that lack this essential protease. Ultrathin sagittal sections of maxillary incisors from 8-wk-old wild-type (WT), Mmp20-null (KO), and heterozygous (HET) littermates were prepared. Secretory-stage enamel ultrastructures from each genotype as a function of development were compared using transmission electron microscopy, selected area electron diffraction, and Raman microspectroscopy. Characteristic rod structures observed in WT enamel exhibited amorphous features in newly deposited enamel, which subsequently transformed into apatite-like crystals in older enamel. Surprisingly, initial mineral formation in KO enamel was found to proceed in the same manner as in the WT. However, soon after a rod structure began to form, large plate-like crystals appeared randomly within the developing KO enamel layer. As development continued, observed plate-like crystals became dominant and obscured the appearance of the enamel rod structure. Upon formation of these plate-like crystals, the KO enamel layer stopped growing in thickness, unlike WT and HET enamel layers that continued to grow at the same rate. Raman results indicated that Mmp20-KO enamel contains a significant portion of octacalcium phosphate, unlike WT enamel. Although normal in all other respects, large, randomly dispersed mineral crystals were observed in secretory HET enamel, although to a lesser extent than that seen in KO enamel, indicating that the level of MMP20 expression has a proportional effect on suppressing aberrant mineral formation. In conclusion, we found that proteolysis of extracellular enamel matrix proteins by MMP20 is not required for the initial development of the enamel rod structure during the early secretory stage of amelogenesis. Proteolysis by MMP20, however, is essential for the prevention of abnormal crystal formation during amelogenesis.


Asunto(s)
Proteínas del Esmalte Dental , Metaloproteinasa 20 de la Matriz , Ameloblastos , Amelogénesis , Amelogenina , Animales , Ratones , Proteolisis
19.
Neuron ; 11(2): 387-400, 1993 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8352946

RESUMEN

Tyrosine phosphorylation plays a central role in the control of neuronal cell development and function. Yet, few neuronal protein tyrosine phosphatases (PTPs) have been identified. We examined rat olfactory neuroepithelium for expression of novel PTPs potentially important in neuronal development and regeneration. Using the polymerase chain reaction with degenerate DNA oligomers directed to the conserved tyrosine phosphatase domain, we identified 6 novel tyrosine phosphatases. One of these, PTP NE-3, is a receptor-type PTP expressed selectively in both rat brain and olfactory neuroepithelium. In the olfactory neuroepithelium, PTP NE-3 expression is restricted to neurons and describes a novel pattern of expression with a high level in the immature neurons and a lower level in mature olfactory sensory neurons.


Asunto(s)
Vías Olfatorias/crecimiento & desarrollo , Vías Olfatorias/metabolismo , Proteínas Tirosina Fosfatasas/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Epitelio/crecimiento & desarrollo , Epitelio/metabolismo , Histocitoquímica , Hibridación in Situ , Masculino , Datos de Secuencia Molecular , Proteínas Tirosina Fosfatasas/genética , Ratas , Ratas Sprague-Dawley , Distribución Tisular
20.
J Neurol ; 255(11): 1657-61, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18677633

RESUMEN

Through the cerebellar vermis, the vestibular nerves are known to influence the basal ganglia and the limbic system. By means of noisy galvanic vestibular stimulation (GVS), it may be possible to ameliorate movement disorders, particularly akinesic symptoms, in patients with central neurodegenerative disorders. We evaluated the effect of 24-hour noisy GVS on a power-law temporal autocorrelation exponent of daytime wrist activity, separately for higher (local maxima) and lower (local minima) levels of activity, in 14 hospitalized patients. The power-law exponent for the local maxima was significantly (p < 0.002) lower with the noisy GVS than with sham stimulation, suggestive of more frequent switching behavior from low to high levels of activity or less severe akinesia. The noisy GVS may thus potentially improve certain motor dysfunctions in patients with distinct central neurodegenerative diseases.


Asunto(s)
Terapia por Estimulación Eléctrica , Actividad Motora , Enfermedades Neurodegenerativas/terapia , Nervio Vestibular/fisiología , Adulto , Anciano , Discinesias/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Muñeca
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