RESUMEN
As a first step towards an acoustic localisation device for coronary stenosis to provide a non-invasive means of diagnosing arterial disease, measurements are reported for an agar-based tissue mimicking material (TMM) of the shear wave propagation velocity, attenuation and viscoelastic constants, together with one dimensional quasi-static elastic moduli and Poisson's ratio. Phase velocity and attenuation coefficients, determined by generating and detecting shear waves piezo-electrically in the range 300 Hz-2 kHz, were 3.2-7.5 ms(-1) and 320 dBm(-1). Quasi-static Young's modulus, shear modulus and Poisson's ratio, obtained by compressive or shear loading of cylindrical specimens were 150-160 kPa; 54-56 kPa and 0.37-0.44. The dynamic Young's and shear moduli, derived from fitting viscoelastic internal variables by an iterative statistical inverse solver to freely oscillating specimens were 230 and 33 kPa and the corresponding relaxation times, 0.046 and 0.036 s. The results were self-consistent, repeatable and provide baseline data required for the computational modelling of wave propagation in a phantom.
Asunto(s)
Agar/química , Materiales Biomiméticos/química , Módulo de Elasticidad , Fantasmas de Imagen , Animales , Estenosis Coronaria/diagnóstico por imagen , Estenosis Coronaria/fisiopatología , Humanos , UltrasonografíaRESUMEN
The potential internal occupational exposure encountered as a consequence of the 232Th-233U fuel cycle are likely to arise predominantly from the inhalation of 232Th, 233U and (232Th + 233U) compounds of absorption Types M and S. In the past, although direct and indirect methods for assessments of internal exposure to 232Th and its daughters were developed, standardised and employed, no such attempts have been made with regard to 233U and 233U + 232Th. Therefore, feasibility studies for assessing internal exposure to 233U have been conducted using three methods: urine bioassay, in vivo counting and measurement of thoron gas in the exhaled breath of a worker. This paper describes details of these studies and discusses the results obtained.
Asunto(s)
Pulmón/metabolismo , Exposición Profesional/análisis , Radiometría/métodos , Uranio/farmacocinética , Uranio/orina , Urinálisis/métodos , Recuento Corporal Total/métodos , Contaminantes Radiactivos del Aire/farmacocinética , Contaminantes Radiactivos del Aire/orina , Estudios de Factibilidad , Humanos , Exposición por Inhalación , Dosis de Radiación , Uranio/análisisRESUMEN
The polyamines spermidine and spermine along with the diamine putrescine are involved in many cellular processes, including chromatin condensation, maintenance of DNA structure, RNA processing, translation and protein activation. The polyamines influence the formation of compacted chromatin and have a well-established role in DNA aggregation. Polyamines are used in the posttranslational modification of eukaryotic initiation factor 5A, which regulates the transport and processing of specific RNA. The polyamines also participate in a novel RNA-decoding mechanism, a translational frame-shift, of at least two known genes, the TY1 transposon and mammalian antizyme. Polyamines are crucial for their own regulation and are involved in feedback mechanisms affecting both polyamine synthesis and catabolism. Recently, it has become apparent that the polyamines are able to influence the action of the protein kinase casein kinase 2. Here we address several roles of polyamines in gene expression.
Asunto(s)
Regulación de la Expresión Génica/fisiología , Espermidina/fisiología , Espermina/fisiología , Animales , Quinasa de la Caseína II , ADN/química , ADN/genética , Humanos , Conformación de Ácido Nucleico , Biosíntesis de Proteínas , Procesamiento Proteico-Postraduccional , Proteínas Serina-Treonina Quinasas/metabolismo , Putrescina/fisiología , Transcripción GenéticaAsunto(s)
Enfermería , Educación en Enfermería , Humanos , India , Consejo Internacional de EnfermerasRESUMEN
A considerable volume of animal pharmacologic data support the view that increased flux through the polyol pathway provides a unifying hypothesis for the major complications of diabetes. An extensive clinical program has been established to verify the extrapolation of the animal pharmacologic findings to man. Clinical data accumulated to date confirm the biochemical and electrophysiologic effects, and encouraging evidence of a drug effect in diabetic neuropathy and retinopathy has already been observed. In the large, controlled safety data base already available, the long-term clinical use of sorbinil is devoid of significant adverse effects in terms of both subjective side effects and laboratory parameters. The only clinically important adverse reaction reported to date has been a hypersensitivity reaction in the early weeks of therapy, which is similar to that seen with other hydantoins.
Asunto(s)
Aldehído Reductasa/antagonistas & inhibidores , Diabetes Mellitus/tratamiento farmacológico , Imidazoles/uso terapéutico , Imidazolidinas , Deshidrogenasas del Alcohol de Azúcar/antagonistas & inhibidores , Animales , Enfermedades del Sistema Nervioso Autónomo/tratamiento farmacológico , Glucemia/análisis , Ensayos Clínicos como Asunto , Neuropatías Diabéticas/tratamiento farmacológico , Retinopatía Diabética/tratamiento farmacológico , Método Doble Ciego , Humanos , Dolor/tratamiento farmacológico , Ratas , Sorbitol/sangreRESUMEN
Extensive animal data now exist to indicate potential benefit of sorbinil in the treatment of the major complications of diabetes mellitus. A clinical programme has been constructed to explore this therapeutic potential and encouraging evidence of drug effect has already been observed in patients with neuropathy and retinopathy. Two small preliminary studies in patients with painful neuropathy have shown that clinically significant reduction of pain was more frequently achieved with sorbinil than with placebo. A 6-month study of patients with retinopathy, using vitreous fluorophotometry as the criterion of retinal damage, showed significant (p = 0.03) benefit for the sorbinil group compared with the placebo group. Drug evaluation in these areas is complex and difficult but it is anticipated that the accumulation of additional data will further substantiate the efficacy suggested by these early findings. The only clinically important adverse effect of sorbinil is the hypersensitivity reaction. This usually occurs during the initial weeks of therapy and is similar to that seen with phenytoin. The long term use of sorbinil is without significant adverse effects.
Asunto(s)
Aldehído Reductasa/antagonistas & inhibidores , Neuropatías Diabéticas/tratamiento farmacológico , Retinopatía Diabética/tratamiento farmacológico , Imidazoles/uso terapéutico , Imidazolidinas , Deshidrogenasas del Alcohol de Azúcar/antagonistas & inhibidores , Animales , Hipersensibilidad a las Drogas/etiología , Electrofisiología , Humanos , Imidazoles/efectos adversosRESUMEN
In a double-blind study of 24 healthy volunteers treated with daily doses of 150 mg flurbiprofen, 600 mg phenylbutazone, 2.1 g aspirin, or placebo for 7 days, assessments were made of faecal blood loss before, during and after treatment. Measurementl body showed that aspirin produced the greatest degree of blood loss. Although both flurbiprofen and phenylbutazone produced greater blood loss than did placebo, the difference from pre-treatment values was not significant, and the levels returned almost to normal in the post-treatment period.
Asunto(s)
Aspirina/efectos adversos , Flurbiprofeno/efectos adversos , Hemorragia Gastrointestinal/inducido químicamente , Fenilbutazona/efectos adversos , Propionatos/efectos adversos , Adulto , Ensayos Clínicos como Asunto , Método Doble Ciego , Heces/análisis , Humanos , MasculinoRESUMEN
Vitamin B-12 absorption of 12 healthy young male subjects was determined by using labelled vitamin B-12 by Schilling's test and whole body retention test. The whole body retention test was performed first using low energy Co57 isotope and a week later, Schilling's test was performed. Whole body retention showed a mean absorption of 56.5% while Schilling's test showed mean absorption of 16.9% in the same subjects. Data supports the whole body retention test being more accurate.