Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 94
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Brain Inj ; 33(10): 1347-1353, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31335209

RESUMEN

Objectives: Studies showed that the recovery of patients with Unresponsive Wakefulness Syndrome (UWS) is also correlated to the recovery of circadian rhythms. In this study, we observed the correlations between patients with UWS biometrical and ambient parameters. Methods: A dedicated monitoring system was realized to record and correlate the level of noise and luminosity with biometric Heart Rate (HR), Heart Rate Variability (HRV) and Breath Rate (BR) parameters. Eleven patients with UWS were recruited and monitored for 13 ± 7 days. Correlation of ambient and biometric parameters was analyzed by Spearman's test. Wilcoxon's test was used to compare the biometric parameters in two different moments of daily activity in the rehabilitation unit (night and day). Patients showed a moderate negative or positive correlation between biometric and ambient parameters. Results: Significant differences between night and morning (0.0001 < p ≤ 0.001) were found for HR, HRV and BR in seven, five and four patients, respectively, at Wilcoxon's test. HR and BR were higher during the night while HRV was lower. Conclusion: In patients with UWS, lower HRV and higher HR and BR during the night might be indicative of interference in sleep/wake cycles. The modifications of the environment surrounding the patient due to the unit procedures of the staff and/or some interaction modalities of the relatives may have an effect on residual endogenous mechanisms of self-regulation. However, differences between night and day in the biometrical parameters are not necessarily linked to the changes in the environment care unit.


Asunto(s)
Sistema Nervioso Autónomo/fisiopatología , Trastornos de la Conciencia/fisiopatología , Ambiente , Hospitalización , Adulto , Anciano , Anciano de 80 o más Años , Electrocardiografía , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Frecuencia Respiratoria , Síndrome , Vigilia , Adulto Joven
2.
J Intellect Disabil Res ; 63(9): 1086-1096, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31017354

RESUMEN

BACKGROUND: Occupational self-analysis programmes have been developed to promote health, mainly in older adults. However, we have found no published studies dealing with this in people with intellectual disability (ID). The aim of this study was to examine the effectiveness of an occupational self-analysis programme in people with ID, focusing on the areas of subjective health perception and participation. METHODS: This study explored the benefits of the 'Occupational Self-Analysis Programme' in people with ID. The intervention group comprised 12 participants and the control group comprised 13 participants. Outcomes were measured using the SF-36 Health Survey and the Role Checklist. The contents of participants' journals and a focus group discussion were also analysed. RESULTS: Compared with the control group, the intervention group showed statistically significant improvements in role limitations because of physical health and role limitations because of emotional problems, social functioning and the cumulative scores of the mental component in the SF-36 Health Survey. The qualitative analysis revealed that participants in the intervention group increased their participation in activities related with daily living, leisure, employment seeking and acquisition, and social participation. These participants also became more aware of issues that lead to a greater engagement in meaningful occupations. CONCLUSION: This programme allowed participants to engage in meaningful activities with other people and to increase their perceived health status by raising awareness of the strengths and difficulties of participation.


Asunto(s)
Actividades Cotidianas , Empleo , Promoción de la Salud , Discapacidad Intelectual/rehabilitación , Actividades Recreativas , Terapia Ocupacional/métodos , Evaluación de Procesos y Resultados en Atención de Salud , Participación Social , Adolescente , Adulto , Femenino , Humanos , Masculino , Terapia Ocupacional/instrumentación , Proyectos Piloto , Evaluación de Programas y Proyectos de Salud , Investigación Cualitativa , Adulto Joven
3.
Metrologia ; 53(Technical Suppl)2016.
Artículo en Inglés | MEDLINE | ID: mdl-28066029

RESUMEN

A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures over the range -30 °C TO +20 °C was carried out by the National Institute of Standards and Technology (NIST, USA) and the Laboratorio Costarricense de Metrología (LACOMET, Costa Rica), between February 2015 and August 2015. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and LACOMET and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining the degree of equivalence between the dew/frost-point standards of NIST and LACOMET.

4.
Scand J Rheumatol ; 42(6): 437-44, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23607571

RESUMEN

OBJECTIVES: To monitor repair of bone erosions using magnetic resonance imaging (MRI) in patients with rheumatoid arthritis (RA) during etanercept combination therapy. METHOD: The study population comprised 29 RA patients [biologic-naïve, 28-joint Disease Activity Score (DAS28) ≥ 3.2] starting etanercept combination therapy with disease-modifying anti-rheumatic drugs (DMARDs) and completing the 1-year study period with the same treatment. Clinical and laboratory assessments and MRI of the hand were performed at baseline and at 1 year. MRI findings were scored by two readers using the Rheumatoid Arthritis MRI Scoring System (RAMRIS). Both readers were blind to the chronological order of the MRI scans, the identity of the patients, and clinical and other imaging data. Tenosynovitis was also scored. The intra- and inter-reader intraclass correlation coefficients (ICCs) were calculated, along with the sensitivity to change with the smallest detectable difference (SDD). Repair of erosions was defined as a RAMRIS score of at least 1 point lower than baseline. RESULTS: The mean RAMRIS score for erosions did not change but all other inflammatory MRI parameters decreased significantly. In 19 patients, the RAMRIS score for erosions remained unchanged after 1 year. In five patients the score decreased after 1 year, although the decrease exceeded the SDD in only one patient (3.4%). CONCLUSIONS: Etanercept combined with DMARDs stopped the progression of erosions, as measured by the RAMRIS, in 82.8% of our RA patients and occasional repair of bone erosions occurred after 1 year of treatment.


Asunto(s)
Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/patología , Huesos/patología , Inmunoglobulina G/uso terapéutico , Receptores del Factor de Necrosis Tumoral/uso terapéutico , Adulto , Progresión de la Enfermedad , Quimioterapia Combinada , Etanercept , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Tenosinovitis/patología , Resultado del Tratamiento
5.
Energy Environ Sci ; 16(4): 1520-1530, 2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-37063253

RESUMEN

Solar batteries capable of harvesting sunlight and storing solar energy present an attractive vista to transition our energy infrastructure into a sustainable future. Here we present an integrated, fully earth-abundant solar battery based on a bifunctional (light absorbing and charge storing) carbon nitride (K-PHI) photoanode, combined with organic hole transfer and storage materials. An internal ladder-type hole transfer cascade via a transport layer is used to selectively shuttle the photogenerated holes to the PEDOT:PSS cathode. This concept differs from previous designs such as light-assisted battery schemes or photocapacitors and allows charging with light during both electrical charge and discharge, thus substantially increasing the energy output of the cell. Compared to battery operation in the dark, light-assisted (dis)charging increases charge output by 243%, thereby increasing the electric coulombic efficiency from 68.3% in the dark to 231%, leading to energy improvements of 94.1% under illumination. This concept opens new vistas towards compact, highly integrated devices based on multifunctional, carbon-based electrodes and separators, and paves the way to a new generation of earth-abundant solar batteries.

6.
J Med Genet ; 46(1): 64-7, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19124644

RESUMEN

BACKGROUND: Neurogenic muscle weakness, ataxia and retinitis pigmentosa (NARP) syndrome have been associated to m.8993T>G/C mutations in the subunit 6 of the ATP synthase (p.MT-ATP6). METHODS: We have performed a mutational screening of the mitochondrial DNA gene encoding for this protein in 62 patients with the disease, that do not carry any of the common mutations described to date. RESULTS: We report clinical and molecular data in one patient who harbours a de novo insertion in the MT-ATP6 gene that results in a truncated subunit. The mutation was heteroplasmic (85%) in muscle DNA and the BN-PAGE analysis showed a clear decrease in the amount of ATP synthase. CONCLUSION: Molecular analysis of NARP patients cannot be limited to the search of the m.8993T>G/C and either the ATP6 or the whole mtDNA should be sequenced.


Asunto(s)
Ataxia/genética , ADN Mitocondrial/genética , ATPasas de Translocación de Protón Mitocondriales/genética , Debilidad Muscular/genética , Retinitis Pigmentosa/genética , Adulto , Secuencia de Aminoácidos , Secuencia de Bases , Encéfalo/patología , Humanos , Masculino , Datos de Secuencia Molecular , Mutación Puntual , Análisis de Secuencia , Síndrome
7.
Chemosphere ; 248: 126029, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32035385

RESUMEN

The use of electrokinetic Fenton (EK Fenton) process, as promising soil remediation approach, was investigated by using an iron electrode with different supporting electrolytes (tap water, H2O2, and citric acid) to depollute soil spiked with petroleum where kaolin was selected as low hydraulic conductivity. The results clearly confirm that, the combination of electrokinetic remediation (EK) and Fenton technologies, is an efficient oxidizing approach for removing hydrocarbons from this kind of soil. In fact, the electrokinetic Fenton reactions and the control of the soil pH conditions by adding citric acid enhanced the oxidation process because the addition of the H2O2 with iron electrode resulted in higher removal efficiencies (89%) for total petroleum hydrocarbons (TPHs). These figures allowed to confirm that EK Fenton process with pH control contributed for the transport of H2O2 and Fe2+ ions in the soil by electromigration and eletro-osmotic phenomena. Conversely, no control of pH conditions when only EK was applied, achieved lower hydrocarbons removal (27%) after 15 d of treatment due to the precipitation of iron ions. Finally, the efficiency of the EK Fenton remediation prevented the generation of secondary effluent with higher organic content, avoiding its treatment by other advanced oxidation process.


Asunto(s)
Restauración y Remediación Ambiental/métodos , Contaminación por Petróleo , Contaminantes del Suelo/química , Ácido Cítrico/química , Técnicas Electroquímicas/instrumentación , Electrodos , Restauración y Remediación Ambiental/instrumentación , Hidrocarburos/química , Peróxido de Hidrógeno/química , Concentración de Iones de Hidrógeno , Hierro/química , Caolín/química , Ósmosis , Oxidación-Reducción , Suelo/química
8.
Science ; 156(3779): 1243-4, 1967 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-6025545

RESUMEN

Model compounds are described for the study of the properties of amino acid side chains in the surface of micelles. Mixed micelles of N-(alpha)- mnyristoyl-L- histidine and cetyltrimethylammonium bromide catalyze the hydrolyses of p-nitrophenyl acetate and p-nitrophenyl caprylate at much higher rates than imidazole or histidinie do. The reaction shows a kinetic behavior similar to that of surface-catalyzed reactions.


Asunto(s)
Coloides , Ácidos Grasos , Histidina , Compuestos de Amonio Cuaternario , Bromo , Caprilatos , Catálisis , Fenómenos Químicos , Química Física , Cinética , Nitrofenoles , Fenilacetatos
9.
Equine Vet J ; 41(2): 153-9, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19418744

RESUMEN

REASONS FOR PERFORMING STUDY: Standing surgical procedures are performed commonly in horses under sedation. This approach minimises the morbidity/mortality risks associated with general anaesthesia. The use of a medetomidine and morphine combination has not been investigated in horses despite the usefulness of each drug individually. OBJECTIVE: To determine the efficacy of a medetomidine and morphine combination to produce standing sedation with minimal cardiorespiratory changes and adequate analgesia for exploratory laparascopy in mature horses. HYPOTHESIS: The combination of medetomidine and morphine will induce reliable sedation with minimal cardiorespiratory changes. METHODS: Medetomidine (5 microg/kg bwt i.v.) followed in 10 min by morphine (50 microg/kg bwt i.v.) and 10 min later by a constant rate infusion (CRI) of medetomidine and morphine (5 and 30 microg/kg bwt/h, respectively) was administered in 7 horses undergoing standing exploratory laparoscopy. Quality of sedation and cardiorespiratory function were assessed. RESULTS: Sedation was satisfactory after the medetomidine and morphine bolus. The CRI of both drugs enhanced sedation and ataxia. Mean visual analogue scores on a scale of 10 varied between 7.8 and 8.8 and were similar between anaesthesiologists and surgeons. Heart rate, respiratory rate and packed cell volume (PCV) decreased significantly after medetomidine and, at some periods, during the CRI. Blood pressure only increased significantly at 5 min and arterial O2 decreased significantly at 10 min post medetomidine. PCV remained significantly lower and total protein decreased post morphine and CRI administration. Arterial CO2 increased towards the end of the CRI. Cardiac output did not change significantly over time. CONCLUSION AND CLINICAL RELEVANCE: The combination of medetomidine and morphine results in reliable sedation and stable cardiorespiratory function in horses undergoing exploratory laparascopy.


Asunto(s)
Caballos/fisiología , Laparoscopía/veterinaria , Medetomidina/administración & dosificación , Morfina/administración & dosificación , Analgésicos Opioides/administración & dosificación , Analgésicos Opioides/efectos adversos , Animales , Análisis de los Gases de la Sangre/veterinaria , Presión Sanguínea/efectos de los fármacos , Quimioterapia Combinada , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Hipnóticos y Sedantes/administración & dosificación , Hipnóticos y Sedantes/efectos adversos , Infusiones Intravenosas/veterinaria , Laparoscopía/métodos , Masculino , Medetomidina/efectos adversos , Morfina/efectos adversos , Respiración/efectos de los fármacos
10.
Water Sci Technol ; 59(7): 1371-6, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19381003

RESUMEN

This paper discusses H(2)S, NH(3) and VOCs removal by sewage-sludge-derived materials with outstanding chemical and textural properties. These materials were obtained from different precursors using different chemical and thermal treatments. Results show that the H(2)S removal process entailed a catalytic conversion of H(2)S to S or SO(4) (2-) species. On the other hand, adsorption is the main mechanism governing the performance of sludge-based materials for NH(3) and VOCs. Retention capacities (x/M values) obtained for some of the sludge-based adsorbents/catalysts are similar to those obtained with commercial activated carbons selected as reference materials.


Asunto(s)
Amoníaco/aislamiento & purificación , Sulfuro de Hidrógeno/aislamiento & purificación , Odorantes , Aguas del Alcantarillado/química , Compuestos Orgánicos Volátiles/aislamiento & purificación , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos , Adsorción , Catálisis
12.
Chemosphere ; 65(1): 132-40, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16564562

RESUMEN

This paper focuses on physical activation (CO2) and chemical activation (H3PO4, NaOH and KOH) of sewage sludge-based precursors. Our results show that (i) a simple acid washing treatment leads to a significant increase in the adsorption capacity of some precursors; (ii) under the experimental conditions tested, CO2 physical activation and chemical activation with H3PO4 were ineffective for an efficient porosity development and (iii) choosing an appropriate protocol, it is possible to obtain highly porous materials (700-1700 m2 g(-1)) by chemical activation of sludge-based precursors with alkaline hydroxides. The efficiency of the chemical activation with NaOH or KOH is very much influenced by the method used for mixing the activating agent and the precursor. The BET values of the materials obtained when physically mixing ground hydroxides with the precursor almost doubled the values obtained if other mixing methods are employed. Increasing the hydroxide:precursor ratio leads to an enhancement of the adsorption capacity of the adsorbents, with BET values ranging from 689 to 1224 m2 g(-1) for NaOH activation and from 853 to 1686 m2 g(-1) for KOH activation.


Asunto(s)
Materiales Manufacturados , Aguas del Alcantarillado/química , Adsorción , Porosidad , Propiedades de Superficie
13.
Rev Neurol ; 43(7): 416-24, 2006.
Artículo en Español | MEDLINE | ID: mdl-17006861

RESUMEN

AIM: The diseases of the oxidative phosphorylation system consist of a group of disorders originated by a deficient synthesis of adenosine triphosphate (ATP). These diseases are increasingly being diagnosed among patients with multisystemic disorders. Mitochondrial deoxyribonucleic acid (mtDNA) mutations are usually maternally inherited, but they also can be sporadic or secondary to nuclear mutations, that are inherited in a Mendelian mode, or due to environmental hazards. In this review we will update, from a genetic point of view, the knowledge on human mitochondrial diseases, remarking the difficulties to study these pathologies. DEVELOPMENT: To mirror these difficulties, we will use selected examples of mutations in the mitochondrial genome, and review recent advances on mitochondrial pathology due to mutations in the nuclear genes codifying for mitochondrial proteins that participate in a good performance of the oxidative phosphorylation system. CONCLUSIONS: Sequencing of the complete human mtDNA should be part of the basic profile in the study of mitochondrial diseases. Due to the increasing number of nuclear genes involved in the oxidative phosphorylation system performance, their analysis should be based on solid biochemical clues.


Asunto(s)
Enfermedades Mitocondriales/metabolismo , Fosforilación Oxidativa , ADN Mitocondrial/genética , Humanos , Enfermedades Mitocondriales/genética , Mutación
14.
ACS Energy Lett ; 1(1): 323-331, 2016 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-28066822

RESUMEN

In this Perspective we discuss the implications of employing metal particles of different shape, size, and composition as absorption enhancers in methylammonium lead iodide perovskite solar cells, with the aim of establishing some guidelines for the future development of plasmonic resonance-based photovoltaic devices. Hybrid perovskites present an extraordinarily high absorption coefficient which, as we show here, makes it difficult to extrapolate concepts and designs that are applied to other solution-processed photovoltaic materials. In addition, the variability of the optical constants attained from perovskite films of seemingly similar composition further complicates the analysis. We demonstrate that, by means of rigorous design, it is possible to provide a realistic prediction of the magnitude of the absorption enhancement that can be reached for perovskite films embedding metal particles. On the basis of this, we foresee that localized surface plasmon effects will provide a means to attain highly efficient perovskite solar cells using films that are thinner than those usually employed, hence facilitating collection of photocarriers and significantly reducing the amount of potentially toxic lead present in the device.

15.
Biochim Biophys Acta ; 928(1): 107-13, 1987 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-3828399

RESUMEN

Treatment of intact isolated rat testis interstitial cells with S-adenosylmethionine as methyl donor, increases substantially the number of LH human CG receptors (100-200%) without modifying the equilibrium dissociation constant. The increase in binding capacity was associated with an augmentation in the sensitivity of the rat testis interstitial cells to produce testosterone in response to LH, suggesting a functional role of the unmasked receptors. The amount of S-adenosylmethionine necessary to obtain an increase in LH binding capacity and preserve cell viability was 25-50 micrograms/ml per 1.6 X 10(7) cells. 10 mM MgCl2 in addition to the Mg2+ present in the medium was necessary to maintain cell viability. 3H-labelled methyl groups were incorporated mainly into the lipid fraction (208 fmol/10(6) cells) when 3H-S-adenosylmethionine was incubated with the cells for 2 h at 30 degrees C. Our results are consistent with the conclusion that early action of LH may involve an activation of methyltransferase activity, phospholipid methylation, an increase in LH binding capacity and an increase in receptor function.


Asunto(s)
Hormona Luteinizante/fisiología , Lípidos de la Membrana/fisiología , Receptores de HL/fisiología , Testículo/fisiología , Animales , Membrana Celular/fisiología , Supervivencia Celular/efectos de los fármacos , Gonadotropina Coriónica/metabolismo , Técnicas In Vitro , Masculino , Metilación , Ratas , S-Adenosilmetionina/farmacología , Testosterona/biosíntesis
16.
Diabetes ; 25(4): 268-74, 1976 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-773723

RESUMEN

Vascular responsiveness to infused angiotensin II and to norepinephrine was determined in 14 normal subjects and two groups of diabetic subjects, 16 with no clinically detectable diabetic complications and 14 with diabetic retinopathy but no clinical evidence of nephropathy. All were maintained on a 100-mEq. -Na- 100-mEq. -K diet. Serum electrolytes, 24-hour urinary sodium, creatinine clearance, and plasma renin activity did not differ significantly among the groups. Group mean baseline diastolic pressure in those with retinopathy was higher than in normal subjects but no significantly different from that of uncomplicated diabetics. The pressor dose of angiotensin II (ng./kg./min. to increase diastolic blood pressure 20 mm. Hg) for each group respectively was 11.5 +/-0.9, 12.9+/- 1.3, and 8.3 +/- 1.3, and the slope of the dose-response curve (mm. Hg rise in blood pressure resulting from the infusion of 1 ng./kg./min. following the initial increment in blood pressure) was 2.0 +/-0.2, 1.6+/-0.2, 3.3+/- 0.6. For norepinephrine, the pressor doses were 163 +/- 24, 212+/-21, and123 +/- 11 and slopes were 0.17 +/- 0.03, 0.13 +/- 0.02, and 0.20 +/-0.02. Neither diabetic group differed significantly from normal subjects. Diabetics with retinopathy were more sensitive to angiotensin II, pressor dose (P less than 0.059) and slope (P less than 0.02), and to norepinephrine, pressor dose (P less than 0.006) and slope (P =0.05) than those without complications. These data suggest that vascular reactivity is enhanced in diabetics with retinopathy.


Asunto(s)
Angiotensina II/farmacología , Presión Sanguínea/efectos de los fármacos , Diabetes Mellitus/fisiopatología , Norepinefrina/farmacología , Ensayos Clínicos como Asunto , Diabetes Mellitus/sangre , Retinopatía Diabética/fisiopatología , Relación Dosis-Respuesta a Droga , Humanos , Renina/sangre
17.
J Am Coll Cardiol ; 37(7): 1921-8, 2001 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-11401133

RESUMEN

OBJECTIVES: We sought to establish what historical findings are predictive of the cause of syncope. BACKGROUND: The clinical features of the various types of syncope have not been systematically investigated. METHODS: Three hundred forty-one patients with syncope were prospectively evaluated. Each patient was interviewed using a standard questionnaire. A cause of syncope was assigned using standardized diagnostic criteria. RESULTS: A cardiac cause of syncope was established in 23% of the patients, a neurally mediated cause in 58% and a neurologic or psychiatric cause in 1%, and in the remaining 18%, the cause of syncope remained unexplained. In a preliminary analysis including age, gender and the presence of suspected or certain heart disease after the initial evaluation, only heart disease was an independent predictor of a cardiac cause of syncope (odds ratio 16, p = 0.00001), with a sensitivity of 95% and a specificity of 45%. In contrast, the absence of heart disease allowed us to exclude a cardiac cause of syncope in 97% of the patients. In patients with certain or suspected heart disease, the most specific predictors of a cardiac cause were syncope in the supine position or during effort, blurred vision and convulsive syncope. Significant and specific predictors of a neurally mediated cause were time between the first and last syncopal episode >4 years, abdominal discomfort before the loss of consciousness and nausea and diaphoresis during the recovery phase. In the patients without heart disease, palpitation was the only significant predictor of a cardiac cause. CONCLUSIONS: The presence of suspected or certain heart disease after the initial evaluation is a strong predictor of a cardiac cause of syncope. A few historical findings are useful to predict cardiac and neurally mediated syncope in patients with and without heart disease.


Asunto(s)
Cardiopatías/complicaciones , Síncope/diagnóstico , Síncope/etiología , Algoritmos , Femenino , Humanos , Masculino , Anamnesis , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Encuestas y Cuestionarios
18.
J Phys Chem B ; 109(31): 15032-6, 2005 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-16852902

RESUMEN

The present work presents a useful comparison of micropore size distributions (MPSDs) obtained from gas adsorption and image analysis of high-resolution transmission electron micrographs. It is shown that the MPSD obtained for a chemical activated carbon is concordant with that obtained from CO2 adsorption. In addition, this technique has allowed us to obtain the MPSD of a carbon molecular sieve (CMS) prepared in our laboratory by a copyrolysis process, which could only be characterized by CO2 adsorption at 273 K (not by N2 adsorption at 77 K due to diffusional problems). The MPSD obtained by high-resolution transmission electron microscopy (HRTEM) for the CMS is wider than that obtained by CO2 adsorption, suggesting that HRTEM is detecting the closed porosity existing in this sample, which is not accessible to gas adsorption. The existence of closed porosity in the CMS is explained considering the preparation method used. Thus, HRTEM combined with image analysis seems to be useful for structural analysis of narrow micropores including closed porosity.

19.
Thyroid ; 15(7): 668-71, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16053382

RESUMEN

Germline mutations in specific hot spot-codons of the RET proto-oncogene are associated with multiple endocrine neoplasia type 2 (MEN 2). Clinical RET gene testing has been routine for the last 10 years in some countries. In Argentina, RET testing excluding MEN 2B was always reported with a mutation at codon 634, with one exception: we described a novel mutation T > C transition at codon 630 (C630R), the family to which we extend the study in the present report. This family comprised 29 members in four generations including 6 individuals affected with medullary thyroid cancer (MTC), positive for the C630R mutation and normal adrenaline/ noradrenaline and ionized calcium/parathyroid hormone levels. Two asymptomatic mutation carriers aged 5 and 11 years underwent total thyroidectomy. The histopathologic examination showed C-cell hyperplasia and microcarcinoma foci, while preoperative basal calcitonins were normal for both. Our report emphasizes the importance of testing for non-hot spot RET mutations in apparently mutation negative MEN 2 families. Furthermore, it would appear that C630R mirrors C634R in penetrance (100% in this family) and in early age of onset of MTC, although paradoxically, no pheochromocytomas and hyperparathyroidism have developed. In addition to recommending RET testing before 5 years of age; we also can postulate that codon 630 may be the key point along the extracellular domain, important in the tissue-specific penetrance.


Asunto(s)
Carcinoma Medular/genética , Mutación de Línea Germinal/genética , Proteínas Oncogénicas/genética , Penetrancia , Proteínas Tirosina Quinasas Receptoras/genética , Neoplasias de la Tiroides/genética , Adulto , Edad de Inicio , Niño , Preescolar , Salud de la Familia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Linaje , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas c-ret
20.
Endocrinology ; 105(2): 372-81, 1979 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-456316

RESUMEN

Measurements of immunoactive and bioactive serum LH in the rat were performed after optimization of both RIA and rat interstitial cell-testosterone (RICT) assay to measure the low circulating LH levels of intact male rats. The effective sensitivity of the RIA was increased 3- to 5-fold to 6.2 or 4.7 ng RP1/ml by extraction of 1--1.5 ml serum, respectively. Serum LH levels of adult male rats were 48.5 +/- 16.3 ng RP-1/ml (n = 50), became undetectable after hypophysectomy, and were suppressed 50% after estrogen treatment. For RICT assay of serum rat LH, sensitivity was increased 5-fold by reduction of the incubation volume to 0.35 ml containing 2--4 x 10(6) interstitial cells/tube, with a detection limit of 3 ng RP-1 or 0.1 ng pure LH. The within-assay coefficient of variation for measurement of a pool of control male rat serum (126 +/- 19l6 ng RP-1) WAS +/- 12.5% and the between-assay variation was +/- 15%. Bioactive serum LH levels in adult male rats were 124.8 +/- 32.3 ng RP-1/ml or 2.74 +/- 0.71 ng rat LH/ml, with biopotency to immunopotency (B:I) ratios of 2.8 +/- 0.2 and 1.1 +/- 0.1, respectively, that were unchanged during elevations of serum LH by LHRH administration. Pituitary LH content was 726 +/- 183 micrograms RP-1 or 16.4 micrograms rat LH/gland, with B:I ratios of 2.3 +/- 0.4 and 1.0 +/- 0.2, respectively. The difference between B:I ratios in assays employing pure rat LH and assays using the RP-1 preparation was attributable to the presence of alpha-subunit and biologically inactive material in the RP-1 standard. Precise measurements of immunoactive and bioactive rat LH in male rat plasma can not be performed by these modified RICT and RIA procedures. The sensitive RICT assay can also be applied to the measurement of low levels of LH in the serum of primates and other species.


Asunto(s)
Hormona Luteinizante/sangre , Animales , Bioensayo , Concanavalina A , Estabilidad de Medicamentos , Hormona Luteinizante/aislamiento & purificación , Hormona Luteinizante/farmacología , Masculino , Radioinmunoensayo/métodos , Ratas , Testículo/efectos de los fármacos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA