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1.
Hong Kong Med J ; 29(5): 412-420, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37794613

RESUMEN

INTRODUCTION: Telemedicine services worldwide have experienced unprecedented growth since the early days of the coronavirus disease 2019 (COVID-19) pandemic. Multiple studies have shown that telemedicine is an effective alternative to conventional in-person patient care. This study explored the public perception of telemedicine in Hong Kong, specifically among older adults who are most vulnerable to COVID-19. METHODS: Medical students from The Chinese University of Hong Kong conducted in-person surveys of older adults aged ≥60 years. Each survey collected socio-demographic information, medical history, and concerns regarding telemedicine use. Univariate and multivariate logistic regression analyses were conducted to identify statistically significant associations. The primary outcomes were acceptance of telemedicine use during a hypothetical severe outbreak and after the COVID-19 pandemic. RESULTS: There were 109 survey respondents. Multivariate logistic regression analyses revealed that the expectation of government subsidies for telemedicine services was the strongest common driver and the only positive independent predictor of telemedicine use during a hypothetical severe outbreak (P=0.016) and after the COVID-19 pandemic (P=0.003). No negative independent predictors of telemedicine use during a hypothetical severe outbreak were identified. Negative independent predictors of telemedicine use after the COVID-19 pandemic included older age and residence in the New Territories (both P=0.001). CONCLUSION: Government support, such as telemedicine-specific subsidies, will be important for efforts to promote telemedicine use in Hong Kong during future severe outbreaks and after the COVID-19 pandemic. Robust dissemination of information regarding the advantages and disadvantages of telemedicine for the public, especially older adults, is needed.


Asunto(s)
COVID-19 , Telemedicina , Humanos , Anciano , COVID-19/epidemiología , Hong Kong/epidemiología , Pandemias , Estudios Transversales
2.
J Wound Care ; 24(11): 519, 522-4, 526-8, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26551644

RESUMEN

OBJECTIVE: Material testing system is a conventional but destructive method for measuring the biomechanical properties of wound tissues in basic research. The recently developed optical coherence tomography-based air-jet indentation system is a non-destructive method for measuring these properties of soft tissues in a non-contact manner. The aim of the study was to examine the correlation between the biomechanical properties of wound tissues measured by the two systems. METHOD: Young male Sprague-Dawley rats with streptozotocin-induced diabetic were wounded by a 6 mm biopsy punch on their hind limbs. The biomechanical properties of wound tissues were assessed with the two systems on post-wounding days 3, 7, 10, 14, and 21. Wound sections were stained with picro-sirius red for analysis on the collagen fibres. Data obtained on the different days were charted to obtain the change in biomechanical properties across the time points, and then pooled to examine the correlation between measurements made by the two devices. Qualitative analysis to determine any correlation between indentation stiffness measured by the air-jet indentation system and the orientation of collagen fibres. RESULTS: The indentation stiffness is significantly negatively correlated to the maximum load, maximum tensile stress, and Young's modulus by the material testing system (all p<0.05). The orientation of collagen changes with the indentation stiffness over time. CONCLUSION: Our findings support the use of optical coherence tomography-based air-jet indentation system to evaluate the biomechanical properties of wounds in a non-contact manner. It is a potential clinical device to examine the biomechanical properties of chronic wounds in vivo in a repeatable manner.


Asunto(s)
Miembro Posterior/lesiones , Úlcera Cutánea/patología , Aire , Animales , Fenómenos Biomecánicos , Diabetes Mellitus Experimental , Masculino , Ensayo de Materiales/métodos , Ratas , Ratas Sprague-Dawley , Úlcera Cutánea/enfermería , Úlcera Cutánea/prevención & control , Tomografía de Coherencia Óptica , Cicatrización de Heridas
3.
Hong Kong Med J ; 19(3): 207-13, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23650199

RESUMEN

OBJECTIVE. To assess the efficacy and safety of aspirin desensitisation in Chinese patients with coronary artery disease. DESIGN. Case series. SETTING. A regional hospital in Hong Kong. PATIENTS. Chinese patients with coronary artery disease and a history of a hypersensitivity reaction to aspirin or non-steroidal anti-inflammatory drug, who underwent aspirin desensitisation between February 2008 and July 2012. RESULTS. There were 24 Chinese patients with coronary artery disease who were admitted to our unit for aspirin desensitisation during this period. The majority (79%) were clinical admissions for desensitisation; eight (33%) of them developed a hypersensitivity reaction during desensitisation. Half of the latter had only limited cutaneous reactions and were able to complete the desensitisation protocol and developed aspirin tolerance. Overall, 20 (83%) of the patients were successfully desensitised at the initial attempt. No serious adverse reactions occurred in the cohort. Twelve of the patients had significant coronary artery disease revealed by coronary angiography and received a percutaneous coronary intervention, nine of whom received drug-eluting stents while three received bare metal stents due to financial constraints. All 11 successfully desensitised patients received aspirin and clopidogrel as double antiplatelet therapy after percutaneous coronary intervention. The remaining patient had a bare metal stent implant due to failed aspirin desensitisation. CONCLUSION. Given the potentially different genetic basis of aspirin hypersensitivity in different ethnicities, recourse to desensitisation in the Chinese population has not previously been addressed. This study demonstrated that aspirin desensitisation using a rapid protocol can be performed effectively and safely in Chinese patients. Our results were comparable to those in other reported studies involving other ethnicities. Successful aspirin desensitisation permits patients to pursue long-term double antiplatelet therapy that includes aspirin after percutaneous coronary intervention, and thus allows the use of drug-eluting stents as a feasible option.


Asunto(s)
Aspirina/administración & dosificación , Desensibilización Inmunológica/métodos , Hipersensibilidad a las Drogas/terapia , Inhibidores de Agregación Plaquetaria/administración & dosificación , Anciano , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/efectos adversos , Aspirina/efectos adversos , Aspirina/inmunología , Clopidogrel , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Desensibilización Inmunológica/efectos adversos , Stents Liberadores de Fármacos , Femenino , Hong Kong , Humanos , Masculino , Persona de Mediana Edad , Inhibidores de Agregación Plaquetaria/efectos adversos , Inhibidores de Agregación Plaquetaria/inmunología , Estudios Retrospectivos , Stents , Ticlopidina/administración & dosificación , Ticlopidina/análogos & derivados , Ticlopidina/uso terapéutico , Factores de Tiempo
4.
Hong Kong Med J ; 18(4): 276-83, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22865170

RESUMEN

OBJECTIVES. To review the 10-year trend of reperfusion strategies in patients with ST-segment elevation myocardial infarction, and the adoption rate of percutaneous coronary interventions as opposed to thrombolytic therapy. Also to explore why some patients did not receive reperfusion therapy, and document changes in reperfusion strategies after the introduction of primary percutaneous coronary intervention programmes. DESIGN. Case series. SETTING. A regional hospital, Hong Kong. PATIENTS. All patients with ST-segment elevation myocardial infarction from January 2000 to December 2009. RESULTS. There were 1835 patients with ST-segment elevation myocardial infarction in that period, of which 1179 (64.3%) received reperfusion therapy (thrombolytic therapy, 46.0%; primary percutaneous coronary intervention, 17.5%; emergency coronary artery bypass graft, 0.7%). After introduction of the primary percutaneous coronary intervention programme, significantly more ST-segment elevation myocardial infarction cases underwent that particular intervention (1.6% in 2000 increasing to 30.6% in 2009), while the proportion receiving thrombolytic therapy declined (57.4% in 2000 decreasing to 35.0% in 2009). Seven reasons for no reperfusion therapy were identified. The commonest ones were delayed presentation (45.1%), succumbed before reperfusion (16.0%), multiple medical co-morbidities (15.2%), and contra-indication to thrombolytic therapy (14.8%). The proportion without reperfusion therapy due to a contra-indication to thrombolytic therapy declined (22.7% in 2000 decreasing to 4.9% to 2009), whilst an increasing proportion received primary percutaneous coronary interventions. CONCLUSIONS. Primary percutaneous coronary intervention is increasingly used as the reperfusion therapy in ST-segment elevation myocardial infarction and is replacing thrombolytic therapy, though the latter still remains a mainstay of therapy. A significant proportion of ST-segment elevation myocardial infarction cases received no reperfusion due to various reasons.


Asunto(s)
Electrocardiografía , Infarto del Miocardio/terapia , Reperfusión Miocárdica/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Terapia Trombolítica
5.
J Comp Pathol ; 144(2-3): 223-6, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-20875645

RESUMEN

A 14-year-old male mixed breed dog was presented for abdominal distension and abdominal pain. Radiographical examination identified a large space-occupying mass in the abdomen. Necropsy examination revealed the presence of a 12cm hepatic mass that occupied almost half of the abdominal cavity. Microscopically, this mass consisted of spindle-shaped neoplastic cells that were arranged in short streams and interlacing bundles. Immunohistochemically, the neoplastic cells expressed vimentin, S-100, protein gene product 9.5 and neuron specific enolase, but were negative for cytokeratin, smooth muscle actin, melan A and von Willebrand Factor. These findings indicated that the hepatic mass was a primary hepatic peripheral nerve sheath tumour. To our knowledge, this is the first documentation of a primary hepatic malignant peripheral nerve sheath tumour in a dog.


Asunto(s)
Enfermedades de los Perros/patología , Neoplasias Hepáticas/veterinaria , Hígado/patología , Neoplasias de la Vaina del Nervio/veterinaria , Animales , Enfermedades de los Perros/metabolismo , Perros , Resultado Fatal , Inmunohistoquímica/veterinaria , Hígado/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Masculino , Neoplasias de la Vaina del Nervio/metabolismo , Neoplasias de la Vaina del Nervio/patología , Fosfopiruvato Hidratasa/metabolismo , Proteínas S100/metabolismo , Vimentina/metabolismo
6.
Rev Sci Instrum ; 81(10): 10E107, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21033972

RESUMEN

Within the scope of long term research on imaging diagnostics for steady-state plasmas and understanding of edge plasma physics through diagnostics with conventional spectroscopic methods, we have constructed a linear electron cyclotron resonance (ECR) plasma device named Research on Advanced Plasma Imaging and Dynamics (RAPID). It has a variety of axial magnetic field profiles provided by eight water-cooled magnetic coils and two dc power supplies. The positions of the magnetic coils are freely adjustable along the axial direction and the power supplies can be operated with many combinations of electrical wiring to the coils. Here, a 6 kW 2.45 GHz magnetron is used to produce steady-state hydrogen, helium, and argon plasmas with central magnetic fields of 875 and/or 437.5 G (second harmonic). In order to achieve the highest possible plasma performance within the limited input parameters, wall conditioning experiments were carried out. Chamber bake-out was achieved with heating coils that were wound covering the vessel, and long-pulse electron cyclotron heating discharge cleaning was also followed after 4 days of bake-out. A uniform bake-out temperature (150 °C) was achieved by wrapping the vessel in high temperature thermal insulation textile and by controlling the heating coil current using a digital control system. The partial pressure changes were observed using a residual gas analyzer, and a total system pressure of 5×10(-8) Torr was finally reached. Diagnostic systems including a millimeter-wave interferometer, a high resolution survey spectrometer, a Langmuir probe, and an ultrasoft x-ray detector were used to provide the evidence that the plasma performance was improved as we desired. In this work, we present characterization of the RAPID device for various system conditions and configurations.

7.
Hong Kong Med J ; 16(5): 347-53, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20889998

RESUMEN

OBJECTIVE: To review primary percutaneous coronary interventions performed for patients with ST elevation myocardial infarction with a focus on door-to-treatment time, especially after introduction of a new management programme in November 2003. DESIGN: Retrospective study. SETTING: Regional hospital, Hong Kong. PATIENTS: All patients with ST elevation myocardial infarction who underwent primary percutaneous coronary intervention in our hospital from January 2002 to December 2007. RESULTS: In all, 209 patients with ST elevation myocardial infarction had primary percutaneous coronary interventions between January 2002 and December 2007; 140 of them were admitted within office hours, 125 of whom came directly from Accident and Emergency Department. The mean door-to-balloon time of these patients was 115 minutes, and in 41% the time was less than 90 minutes (as recommended by the American College of Cardiology/American Heart Association guidelines). Since introduction of the new programme, the mean door-to-balloon time has diminished significantly, from 146 to 116 minutes (P=0.047). Delay in diagnosis (28%) and Cardiac Catheterization Laboratory being occupied (20%) were the two most common reasons for prolonged door-to-balloon times. CONCLUSION: We achieved satisfactory performance in our primary percutaneous coronary intervention programme, providing timely reperfusion therapy for patients with ST elevation myocardial infarction. A well-organised and systematic clinical pathway is a prerequisite for a centre that provides a timely and effective primary percutaneous coronary intervention service for patients with ST elevation myocardial infarction. Better public education and greater awareness on the part of medical service providers are needed, so as to facilitate urgent revascularisation and improve outcomes in patients with ST elevation myocardial infarction.


Asunto(s)
Angioplastia Coronaria con Balón/métodos , Cateterismo Cardíaco/métodos , Infarto del Miocardio/terapia , Adulto , Anciano , Anciano de 80 o más Años , Angioplastia Coronaria con Balón/estadística & datos numéricos , Cateterismo Cardíaco/estadística & datos numéricos , Diagnóstico Tardío , Servicio de Urgencia en Hospital/estadística & datos numéricos , Femenino , Hong Kong , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Estudios Retrospectivos , Factores de Tiempo
8.
Phys Rev E Stat Nonlin Soft Matter Phys ; 82(4 Pt 1): 041705, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21230293

RESUMEN

We figured out periodic undulations of lamellae "zigzags" in liquid crystals under confinement by glass and patterned silicon hybrid cell, but in the absence of applied fields. The optical and internal structures of zigzags have been investigated from mesoscopic scale to molecular level by convoluting real and reciprocal space probes, such as polarized light microscopy, scanning electron microscopy, and microbeam x-ray diffraction. The homeotropic anchoring happens at air/liquid crystal, while planar one appears at glass or patterned silicon surfaces. The wetting and displacement of lamellae near the glass surface give rise to tilting and bending in the stacking of lamellae. This can provide a solution for the origin of periodic zigzags: asymmetric strain exerted to lamellae at two-dimensional glass surface and one-dimensional-like pattern. This can give a hint for potential photonic applications such as optical gratings and modulators due to its high periodicity.


Asunto(s)
Cristales Líquidos/química , Vidrio/química , Microscopía Electrónica de Rastreo , Difracción de Rayos X
9.
Rev Sci Instrum ; 80(10): 103503, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19895060

RESUMEN

The research on advanced plasma imaging and dynamics (RAPID) device is a newly developed linear electron cyclotron resonance (ECR) plasma device. It has a variety of axial magnetic field profiles provided by eight water-cooled magnetic coils and two dc power supplies. The positions of the magnetic coils are freely adjustable along the axial direction and the power supplies can be operated with many combinations of electrical wiring to the coils. A 6 kW 2.45 GHz magnetron is used to produce steady-state ECR plasmas with central magnetic fields of 875 and/or 437.5 G (second harmonic). The cylindrical stainless steel vacuum chamber is 300 mm in diameter and 750 mm in length and has eight radial and ten axial ports including 6-in. and 8-in. viewing windows for heating and diagnostics. Experimental observation of ECR plasma heating has been recently carried out during the initial plasma operation. The main diagnostic systems including a 94 GHz heterodyne interferometer, a high-resolution 25 channel one-dimensional array spectrometer, a single channel survey spectrometer, and an electric probe have been also prepared. The RAPID device is a flexible simulator for the understanding of tokamak edge plasma physics and new diagnostic system development. In this work, we describe the RAPID device and initial operation results.

10.
Biophys J ; 97(2): 519-27, 2009 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-19619466

RESUMEN

Microtubules (MTs), a major component of the eukaryotic cytoskeleton, are 25 nm protein nanotubes with walls comprised of assembled protofilaments built from alphabeta heterodimeric tubulin. In neural cells, different isoforms of the microtubule-associated-protein (MAP) tau regulate tubulin assembly and MT stability. Using synchrotron small angle x-ray scattering (SAXS), we have examined the effects of all six naturally occurring central nervous system tau isoforms on the assembly structure of taxol-stabilized MTs. Most notably, we found that tau regulates the distribution of protofilament numbers in MTs as reflected in the observed increase in the average radius R(MT) of MTs with increasing Phi, the tau/tubulin-dimer molar ratio. Within experimental scatter, the change in R(MT) seems to be isoform independent. Significantly, R(MT) was observed to rapidly increase for 0 < Phi < 0.2 and saturate for Phi between 0.2-0.5. Thus, a local shape distortion of the tubulin dimer on tau binding, at coverages much less than a monolayer, is spread collectively over many dimers on the scale of protofilaments. This implies that tau regulates the shape of protofilaments and thus the spontaneous curvature C(o)(MT) of MTs leading to changes in the curvature C(MT) (=1/R(MT)). An important biological implication of these findings is a possible allosteric role for tau where the tau-induced shape changes of the MT surface may effect the MT binding activity of other MAPs present in neurons. Furthermore, the results, which provide insight into the regulation of the elastic properties of MTs by tau, may also impact biomaterials applications requiring radial size-controlled nanotubes.


Asunto(s)
Microtúbulos/química , Microtúbulos/metabolismo , Sincrotrones , Proteínas tau/metabolismo , Animales , Bovinos , Línea Celular , Elasticidad , Humanos , Modelos Moleculares , Cloruro de Potasio/farmacología , Unión Proteica/efectos de los fármacos , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Dispersión del Ángulo Pequeño , Electricidad Estática , Difracción de Rayos X , Proteínas tau/química
11.
Langmuir ; 25(3): 1685-91, 2009 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-19133728

RESUMEN

A smectic liquid crystal (LC) containing a rigid biphenyl group and semifluorinated chains exhibits a high density of toric focal conic domains (TFCDs) arranged in an ordered array when confined within a microchannel. The formation of the TFCDs is strongly influenced by the width (W) and depth (h) of the confined microchannels, most importantly, by the channel depth. We studied a broad variety of microchannels, with varying width in the range of 3-200 mum and depth in the range of 2-10 mum. The radius of the TFCDs increases with increases in the width until the saturated radius is achieved, which is determined by the depth of the channel. We used the elastic-anchoring model of TFCD formation to explain the experimental observations. The model allows one to trace the dependence of the TFCD radius on the channel depth h, to explain why the TFCDs do not form in channels that are too shallow or too narrow.

12.
Nat Mater ; 6(11): 866-70, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17934466

RESUMEN

The formation of a large-area ordered structure by organic molecular soft building blocks is one of the most exciting interdisciplinary research areas in current materials science and nanotechnology. So far, several distinct organic building blocks--including colloids, block copolymers and surfactants--have been examined as potential materials for the creation of lithographic templates. Here, we report that perfect ordered arrays of toric focal conic domains (TFCDs) covering large areas can be formed by semi-fluorinated smectic liquid crystals. Combined with controlled geometry, that is, a microchannel, our smectic liquid-crystal system exhibits a high density of TFCDs that are arranged with remarkably high regularity. Direct visualization of the internal structure of the TFCDs clearly verified that the smectic layers were aligned normal to the side walls and parallel to the top surface, and merge with the circular profile on the bottom wall surface. Moreover, we demonstrate a new concept: smectic liquid-crystal lithography. Grown in microchannels from a mixture of liquid-crystal molecules and fluorescent particles, TFCDs of the smectic liquid crystals acted as a template, trapping particles in an ordered array. Our findings pose new theoretical challenges and potentially enable lithographic applications based on smectic liquid-crystalline materials.


Asunto(s)
Cristales Líquidos/química , Nanotecnología/instrumentación , Nanotecnología/métodos , Dióxido de Silicio/química
13.
Hong Kong Med J ; 12(2): 108-14, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16603777

RESUMEN

OBJECTIVE: To assess the clinical applicability, efficacy, and safety of coronary angiography and angioplasty via a transradial approach in local Chinese patients. DESIGN: Prospective case series. SETTING: Regional hospital, Hong Kong. PATIENTS: All patients undergoing coronary angiography and coronary angioplasty between 1 January and 30 June 2004. INTERVENTIONS: Transradial coronary angiography and coronary angioplasty. MAIN OUTCOME MEASURES: Feasibility, success rate, and complications. RESULTS: A total of 268 coronary angiographies (62% of all coronary angiographies) and 118 coronary angioplasties (48% of all coronary angioplasties) were performed via a transradial approach. The procedural success rate for coronary angiography was 93.7% with a mean duration of 21.8 (standard deviation, 13.5) minutes compared with 17.9 (10.0) minutes for angiography via a femoral approach. Most (99%) patients were free from any complications. Of those patients who underwent elective transradial coronary angiography in the morning, 64% were discharged on the same day. Comparison of data in the first half of the study period with those in the second half revealed a significant increase in the percentage of coronary angiographies performed via a transradial approach (from 52% to 73%, P<0.0001), and an improved procedural success rate (from 91.5% to 95.3%, P=0.1). For transradial coronary angioplasty, the procedural success rate was 98%. A total of 246 lesions (2.08 lesions per patient) were treated with no procedure-related complications. CONCLUSIONS: Transradial coronary angiography and angioplasty are feasible in a significant proportion of local Chinese patients and achieve a high success rate and low complication rate. It tends to prolong procedural duration, but improves patients' comfort and permits earlier ambulation and discharge. The procedural success rate improves with accumulating experience.


Asunto(s)
Angioplastia Coronaria con Balón/métodos , Angiografía Coronaria/métodos , Arteria Radial , Anciano , Angioplastia Coronaria con Balón/efectos adversos , Angiografía Coronaria/efectos adversos , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Seguridad , Resultado del Tratamiento
15.
Mar Pollut Bull ; 51(8-12): 1010-7, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16040057

RESUMEN

Green-lipped mussels (Perna viridis) were collected from seven fish culture zones (FCZs) in Hong Kong and analyzed for okadaic acid (OA). A conventional HPLC method was modified by incorporating a proteinase K digestion step. Results suggest that a higher recovery (2.5 times higher) of OA was obtained from spiked samples after the addition of 1.08 mg proteinase K in comparison with samples incubated without the proteolytic enzyme. For the hepatopancreas (HP) of individual field-collected mussels, the additional digestion step can enhance OA extraction by 3.1 times. Spatial and temporal variations in OA concentrations in the mussels from various FCZs were investigated. The highest concentration of OA in mussel HP samples was 1164.9 ng/g HP wet wt. With respect to OA concentrations in whole mussel tissues from seven sites and four seasonal samplings, the concentrations were between 70.0 and 131.0 ng/g wet wt., which did not exceed the generally recognized international regulatory criteria (>200 ng/g) for OA.


Asunto(s)
Bivalvos/química , Monitoreo del Ambiente/estadística & datos numéricos , Toxinas Marinas/análisis , Ácido Ocadaico/análisis , Animales , Cromatografía Líquida de Alta Presión , Endopeptidasa K/química , Geografía , Hepatopáncreas/química , Hong Kong , Estaciones del Año
17.
Vet Rec ; 154(7): 201-4, 2004 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-15002400

RESUMEN

To evaluate the efficacy of a mixture of barium and carboxymethylcellulose (CMC) suspension in upper gastrointestinal contrast studies, and to determine its optimal concentration and method for use, eight healthy beagle dogs underwent conventional upper gastrointestinal contrast imaging and a modified procedure using a mixture of barium sulphate and CMC. Four different procedures were carried out on the dogs at weekly intervals. In the first, the dogs were administered 10 ml/kg of 60 per cent barium suspension for conventional study of the upper gastrointestinal tract. The second, third and fourth procedures involved modified methods in which the dogs were given 10 ml/kg of a mixture of 25 per cent barium and 0.5 per cent CMC prepared to a low, moderate or high viscosity, respectively. All four procedures were evaluated by four criteria: the quality of the images obtained, the translucency and distensibility of the bowel, and the transit time. The method of imaging which used a moderately viscious CMC formulation provided excellent image quality, high translucency, a rapid transit time and suitable bowel distension to enable more precise diagnosis of disorders of the gastrointestinal tract.


Asunto(s)
Sulfato de Bario/administración & dosificación , Carboximetilcelulosa de Sodio/administración & dosificación , Medios de Contraste/administración & dosificación , Sistema Digestivo/diagnóstico por imagen , Perros/fisiología , Motilidad Gastrointestinal/fisiología , Administración Oral , Animales , Femenino , Masculino , Radiografía/veterinaria
18.
Org Lett ; 3(17): 2733-5, 2001 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-11506621

RESUMEN

[reaction: see text]. Optically active aminonaphthol 3 obtained by condensation of 2-naphthol, benzaldehyde, and (S)-methylbenzylamine followed by N-methylation was found to catalyze the enantioselective ethylation of aryl aldehydes to secondary alcohols with high enantioselectivities (up to 99.8%) at room temperature.

19.
J Pediatr ; 137(4): 581-4, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11035844

RESUMEN

Two thousand nine hundred fourteen Chinese children (1510 males and 1404 females) were examined for the presence of scleral melanocytosis (SM) and oculodermal melanocytosis in a cross-sectional prevalence survey. SM was found in 4.9% of boys and 4.1% of girls under the age of 1 year. The peak prevalence was at 6 years of age, when 44.6% of boys and 46.6% of girls were affected. At 18 years of age, only 11.1% of boys and 13.2% of girls had SM. The overall prevalence, regardless of age, was 27.6% in boys and 27. 1% in girls. The condition was bilateral in 78% of cases. The medial superior quadrant was the most frequently affected site, and the lateral inferior quadrant was the least frequently affected site. Oculodermal melanocytosis occurred only in one patient; the pigmentation affected the left side of the face and the ipsilateral sclera.


Asunto(s)
Neoplasias del Ojo/complicaciones , Neoplasias Primarias Múltiples/complicaciones , Nevo de Ota/complicaciones , Enfermedades de la Esclerótica/complicaciones , Neoplasias Cutáneas/complicaciones , Adolescente , Niño , Preescolar , China , Femenino , Humanos , Lactante , Masculino
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