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1.
Stat Med ; 38(8): 1459-1474, 2019 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-30511500

RESUMEN

One Sentence Summary: A Bayesian repeated measures model based on quantitative muscle strength data from a prospective Natural History Study was developed to determine disease progression and design clinical trials for GNE myopathy, a rare and slowly progressive muscle disease. GNE myopathy is a rare muscle disease characterized by slowly progressive weakness and atrophy of skeletal muscles. To address the significant challenges of defining the natural history and designing clinical trials for GNE myopathy, we developed a Bayesian latent variable repeated measures model to determine disease progression. The model is based on longitudinal quantitative muscle strength data collected as part of a prospective Natural History Study. The GNE Myopathy Progression Model provides an understanding of disease progression that would have otherwise required a natural history of unfeasible duration. "Disease age," the model-generated measure of disease progression, highly correlates with a variety of clinical, functional and patient-reported outcomes. With the incorporation of a treatment effect parameter to the GNE Disease Progression Model, we describe a novel GNE Myopathy Disease Modification Analysis that significantly increases power and reduces the number of subjects required to test the effectiveness of novel therapies when compared to more traditional analysis methods. The GNE Myopathy Disease Progression Model and Disease Modification Analysis can be applied to muscle diseases with prospectively collected muscle strength data, and a variety of rare and slowly progressive diseases.


Asunto(s)
Teorema de Bayes , Progresión de la Enfermedad , Miopatías Distales/fisiopatología , Algoritmos , Humanos , Estudios Prospectivos
2.
Clin Oral Investig ; 23(5): 2083-2095, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30251055

RESUMEN

OBJECTIVES: To evaluate the effects of topical applications of porcine acellular urinary bladder matrix (AUBM) and Centella asiatica extract (CAE) on the healing of tongue wounds in a rat model. MATERIALS AND METHODS: Wounds were made in the tongue using a punch tool in 64 male Sprague-Dawley rats, randomized into four groups (n = 16 per group): group 1 (control), group 2 (CAE), group 3 (AUBM mixed with orabase), and group 4 (orabase). No product was applied in group 1 and groups 2-4 received three daily topical applications. The animals were weighed on day 0 and at the time of euthanasia. Four rats in each group were euthanized at days 2, 7, 14, and 21 and the tongues were processed for: macroscopic morphometric analysis, myeloperoxidase (MPO) and malondialdehyde (MDA) levels, histological wound repair (degree of reepithelialization and inflammation), and CD31 positivity. RESULTS: The animals' weight gain, histological wound repair, and CD31 positivity from greatest to least were: AUBM > CAE > orabase > control. Percentage of tongue occupied by wound, MPO, and MPA levels from least to greatest were: AUBM < CAE < orabase < control, whereby the AUBM group showed significant differences (p ≤ 0.05) in comparison with the other groups on days 2, 7, 14, and 21 for percentage of tongue occupied by wound and MDA and on days 7, 14, and 21 for MPO. CONCLUSIONS: CAE is effective for oral tissue regeneration, while AUBM is an even more potent means of oral mucosa regeneration. CLINICAL RELEVANCE: AUBM may be beneficial to patients with oral wounds; this finding requires further clinical and laboratory investigation.


Asunto(s)
Regeneración Tisular Dirigida , Mucosa Bucal/patología , Triterpenos/farmacología , Vejiga Urinaria/trasplante , Cicatrización de Heridas , Animales , Carboximetilcelulosa de Sodio/análogos & derivados , Carboximetilcelulosa de Sodio/farmacología , Centella , Masculino , Extractos Vegetales , Ratas , Ratas Sprague-Dawley , Porcinos
3.
Neurologia (Engl Ed) ; 37(1): 53-60, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35074189

RESUMEN

INTRODUCTION: Dementia is a chronic, degenerative disease with a strong impact on families and health systems. The instruments currently in use for measuring cognitive impairment have different psychometric characteristics in terms of application time, cut-off point, reliability, and validity. The objective of this review is to describe the characteristics of the validated, Spanish-language versions of the Mini-Cog, Clock-Drawing Test, and Mini-Mental State Examination scales for cognitive impairment screening. DEVELOPMENT: We performed a three-stage literature search of articles published on Medline since 1953. We selected articles on validated, Spanish-language versions of the scales that included data on reliability, validity, sensitivity, and specificity. CONCLUSIONS: The 3 screening tools assessed in this article provide support for primary care professionals. Timely identification of mild cognitive impairment and dementia is crucial for the prognosis of these patients.


Asunto(s)
Demencia , Lenguaje , Cognición , Demencia/diagnóstico , Humanos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
4.
Rheumatol Int ; 30(5): 655-9, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19582456

RESUMEN

Tumor necrosis factor-alpha (TNF-alpha) plays a central role in inflammation, and it has been directly implicated in the pathogenesis of rheumatoid arthritis (RA). TNF-alpha activity is mediated through TNFRI and TNFRII cell surface receptors, which act as physiological attenuators of TNF-alpha activity. We recruited 190 RA patients and 190 healthy subjects (HS) in order to associate the -383A>C TNFRI polymorphism with sTNFRI levels and DAS28 score in RA. In results, sTNFRI levels were higher in RA patients than HS (P = 0.04). The -383A>C TNFRI polymorphism did not show significant differences in both studied groups. However, in the RA group the sTNFRI levels were significantly elevated (P = 0.004) in A/A genotype carriers. In addition, the A/A genotype carriers had the higher DAS28 score than A/C genotype (P = 0.02). These data suggest that -383A>C TNFRI polymorphism is not a susceptibility marker in RA, whereas the increased levels of sTNFRI could reflect the clinical activity in RA patients.


Asunto(s)
Artritis Reumatoide/genética , Polimorfismo Genético , Receptores Tipo I de Factores de Necrosis Tumoral/genética , Adulto , Anciano , Anciano de 80 o más Años , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/etnología , Artritis Reumatoide/inmunología , Biomarcadores/sangre , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Masculino , México/epidemiología , Persona de Mediana Edad , Fenotipo , Receptores Tipo I de Factores de Necrosis Tumoral/sangre , Medición de Riesgo , Factores de Riesgo , Índice de Severidad de la Enfermedad , Adulto Joven
5.
Sci Adv ; 6(20): eaaz9165, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32426502

RESUMEN

Dopaminergic neuronal cell death, associated with intracellular α-synuclein (α-syn)-rich protein aggregates [termed "Lewy bodies" (LBs)], is a well-established characteristic of Parkinson's disease (PD). Much evidence, accumulated from multiple experimental models, has suggested that α-syn plays a role in PD pathogenesis, not only as a trigger of pathology but also as a mediator of disease progression through pathological spreading. Here, we have used a machine learning-based approach to identify unique signatures of neurodegeneration in monkeys induced by distinct α-syn pathogenic structures derived from patients with PD. Unexpectedly, our results show that, in nonhuman primates, a small amount of singular α-syn aggregates is as toxic as larger amyloid fibrils present in the LBs, thus reinforcing the need for preclinical research in this species. Furthermore, our results provide evidence supporting the true multifactorial nature of PD, as multiple causes can induce a similar outcome regarding dopaminergic neurodegeneration.


Asunto(s)
Enfermedad de Parkinson , alfa-Sinucleína , Amiloide/metabolismo , Animales , Humanos , Cuerpos de Lewy/química , Cuerpos de Lewy/metabolismo , Cuerpos de Lewy/patología , Enfermedad de Parkinson/metabolismo , Primates
6.
Scand J Rheumatol ; 38(5): 332-5, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19579138

RESUMEN

OBJECTIVE: To measure levels of soluble tumour necrosis factor alpha (TNFalpha) receptor type I (sTNFRI) and type II (sTNFRII) in order to correlate them with C-reactive protein (CRP), rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), and disease activity score (DAS28) in RA patients. METHODS: We recruited 41 RA patients classified according to American College of Rheumatology (ACR) criteria and 38 healthy subjects (HS). sTNFRI and sTNFRII were measured using an enzyme-linked immunosorbent assay (ELISA) kit. Clinical activity in RA patients was evaluated using the Disease Activity Score using 28 joint counts (DAS28). The statistical analysis was realized using SPSS version 10.0. RESULTS: Soluble TNFRI and TNFRII levels were higher in RA patients (p = 0.04 and 0.001, respectively) than HS. Serum levels of sTNFRI correlated with sTNFRII (r = 0.699, p < 0.0001). sTNFRII correlated with DAS28 (r = 0.375, p = 0.017), RF (r = 0.505, p = 0.004), and ESR (r = 0.323, p = 0.042). CONCLUSION: The increased levels of both sTNFRI and sTNFRII suggest a secondary event related to the inflammatory state observed in RA, whereas the correlation of sTNFRII with RF, ESR, and DAS28 reflects the preferential TNFRII shedding induced by TNFalpha. sTNFRII may be useful as an additional inflammatory marker in RA.


Asunto(s)
Artritis Reumatoide/sangre , Receptores Tipo II del Factor de Necrosis Tumoral/sangre , Receptores Tipo I de Factores de Necrosis Tumoral/sangre , Índice de Severidad de la Enfermedad , Adulto , Biomarcadores/sangre , Sedimentación Sanguínea , Proteína C-Reactiva/metabolismo , Estudios de Casos y Controles , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factor Reumatoide/sangre
7.
Neurologia (Engl Ed) ; 2018 May 09.
Artículo en Inglés, Español | MEDLINE | ID: mdl-29753565

RESUMEN

INTRODUCTION: Dementia is a chronic, degenerative disease with a strong impact on families and health systems. The instruments currently in use for measuring cognitive impairment have different psychometric characteristics in terms of application time, cut-off point, reliability, and validity. The objective of this review is to describe the characteristics of the validated, Spanish-language versions of the Mini-Cog, Clock-Drawing Test, and Mini-Mental State Examination scales for cognitive impairment screening. DEVELOPMENT: We performed a three-stage literature search of articles published on Medline since 1953. We selected articles on validated, Spanish-language versions of the scales that included data on reliability, validity, sensitivity, and specificity. CONCLUSIONS: The 3 screening tools assessed in this article provide support for primary care professionals. Timely identification of mild cognitive impairment and dementia is crucial for the prognosis of these patients.

8.
J Neuroimmunol ; 320: 117-124, 2018 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-29661540

RESUMEN

Macrophage migration inhibitory factor (MIF) is a cytokine associated with tissue damage in multiple autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis and psoriatic arthritis. The role of MIF in multiple sclerosis (MS) and the contribution of its polymorphisms are unknown in our population. Therefore, we decided to investigate the genetic association of -794 CATT5-8 (rs5844572) and -173 G>C (rs755622) MIF polymorphisms with MS, clinical variables and MIF serum levels in the population of western Mexico. 230 MS patients diagnosed according to McDonald criteria and 248 control subjects (CS) were recruited for this study, both polymorphisms were genotyped by PCR and PCR-RFLP and MIF serum levels were measured by ELISA kit. Severity and progression of MS were evaluated by EDSS and MSSS scores, respectively. Genotypes carrying the 5 repeats alleles of -794 CATT5-8MIF polymorphism present higher MIF serum levels in comparison with no carriers, and the presence of 5,7 heterozygous genotype contribute to the increase of disease severity and damage progression in MS patients. Notably when we stratified by sex, an effect of risk alleles (7 repeats and -173*C) of both MIF polymorphisms on EDSS and MSSS scores on males was found (p < 0.01). This study suggests that polymorphic alleles of MIF polymorphisms could act as sex-specific disease modifiers that increase the severity and progression of MS in male Mexican-Mestizo western population.


Asunto(s)
Predisposición Genética a la Enfermedad/genética , Oxidorreductasas Intramoleculares/genética , Factores Inhibidores de la Migración de Macrófagos/genética , Esclerosis Múltiple/genética , Caracteres Sexuales , Adulto , Progresión de la Enfermedad , Femenino , Genotipo , Humanos , Masculino , México , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple
9.
Br J Oral Maxillofac Surg ; 55(7): 697-702, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28622916

RESUMEN

The purpose of this study was to analyse the potential of platelet-rich plasma (PRP) culture media to induce osteogenic differentiation of periodontal ligament stem cells and dental pulp stem cells compared with four other methods of culture. Both types of cell were collected from 35 healthy patients and cultured in five different media (Dulbecco's modified eagle's medium (DMEM); DMEM and melatonin; DMEM and PRP; DMEM and ascorbic acid 200µmol; DMEM and l-ascorbate 2-phosphate 50µmol). Cells were characterised by flow cytometry. Alizarin Red stain, alkaline phosphatase stain, and the expression of collagen type 1 (Col-1), runt-related transcription factor (RUNX2), osteoprotegerin, and osteopontin (quantified by qRT-PCR) were used to detect the osteogenic profile in each culture. Flow cytometry showed that both types of stem cell were a homogeneous mixture of CD90(+), CD105(+), STRO-1(+), CD34 (-), and CD45 (-) cells. Dental pulp stem cells that were cultured with PRP showed the best osteogenic profile (RUNX2 p=0.0002; osteoprotegerin p=0.001). The group of these stem cells that showed the best osteogenic profile was also cultured with PRP (osteoprotegerin p=0.001). Medium five (with l-ascorbate 2-phosphate 50µmol added) showed an increase in all osteogenic markers for periodontal ligament stem cells after PRP, while the best culture conditions for osteogenic expression of dental pulp stem cells after PRP was in medium four (ascorbic acid 200µmol added). These results suggested that culture in PRP induces osteogenic differentiation of both types of stem cell, modulating molecular pathways to promote bony formation.


Asunto(s)
Medios de Cultivo , Osteogénesis , Ligamento Periodontal/citología , Plasma Rico en Plaquetas , Células Madre , Adolescente , Adulto , Diferenciación Celular , Células Cultivadas , Humanos , Adulto Joven
10.
Neurología (Barc., Ed. impr.) ; 37(1): 53-60, Jan.-Feb. 2022. ilus, tab
Artículo en Inglés, Español | IBECS (España) | ID: ibc-204463

RESUMEN

Introducción: La demencia es una enfermedad crónica degenerativa de alto impacto para las familias y los sistemas de salud. Los instrumentos de medición del deterioro cognitivo que se utilizan actualmente tienen características psicométricas diferentes en cuanto a tiempo de aplicación, punto de corte, confiabilidad y validez. El objetivo de la presente revisión fue describir las características de las escalas Mini Cog, Prueba del reloj y Mini- Mental para tamizaje de deterioro cognitivo validadas al idioma español. Desarrollo: La búsqueda bibliográfica se realizó en 3 etapas mediante la base de datos Medline a partir del año 1953. Se realizó una selección de publicaciones validadas al español que incluyeran la confiabilidad, validez, sensibilidad y especificidad de las escalas. Conclusiones: Las 3 herramientas de tamizaje descritas en este artículo proporcionan un apoyo para el personal de salud. La detección oportuna es crucial para el pronóstico de las personas que viven con deterioro cognitivo leve o demencia. (AU)


Introduction: Dementia is a chronic, degenerative disease with a strong impact on families and health systems. The instruments currently in use for measuring cognitive impairment have different psychometric characteristics in terms of application time, cut-off point, reliability, and validity. The objective of this review is to describe the characteristics of the validated, Spanish-language versions of the Mini-Cog, Clock-Drawing Test, and Mini–Mental State Examination scales for cognitive impairment screening. Development: We performed a three-stage literature search of articles published on Medline since 1953. We selected articles on validated, Spanish-language versions of the scales that included data on reliability, validity, sensitivity, and specificity. Conclusions: The 3 screening tools assessed in this article provide support for primary care professionals. Timely identification of mild cognitive impairment and dementia is crucial for the prognosis of these patients. (AU)


Asunto(s)
Humanos , Masculino , Femenino , Anciano , Anciano de 80 o más Años , Demencia/diagnóstico , Disfunción Cognitiva , Tamizaje Masivo , Cognición , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
11.
Neurotherapeutics ; 14(4): 1073-1083, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28707277

RESUMEN

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder affecting approximately 45% of male and 16% of female carriers of the FMR1 premutation over the age of 50 years. Currently, no effective treatment is available. We performed an open-label intervention study to assess whether allopregnanolone, a neurosteroid promoting regeneration and repair, can improve clinical symptoms, brain activity, and magnetic resonance imaging (MRI) measurements in patients with FXTAS. Six patients underwent weekly intravenous infusions of allopregnanolone (2-6 mg over 30 min) for 12 weeks. All patients completed baseline and follow-up studies, though MRI scans were not collected from 1 patient because of MRI contraindications. The MRI scans from previous visits, along with scans from 8 age-matched male controls, were also included to establish patients' baseline condition as a reference. Functional outcomes included quantitative measurements of tremor and ataxia and neuropsychological evaluations. Brain activity consisted of event-related potential N400 word repetition effect during a semantic memory processing task. Structural MRI outcomes comprised volumes of the hippocampus, amygdala, and fluid-attenuated inversion recovery hyperintensities, and microstructural integrity of the corpus callosum. The results of the study showed that allopregnanolone infusions were well tolerated in all subjects. Before treatment, the patients disclosed impairment in executive function, verbal fluency and learning, and progressive deterioration of all MRI measurements. After treatment, the patients demonstrated improvement in executive functioning, episodic memory and learning, and increased N400 repetition effect amplitude. Although MRI changes were not significant as a group, both improved and deteriorated MRI measurements occurred in individual patients in contrast to uniform deterioration before the treatment. Significant correlations between baseline MRI measurements and changes in neuropsychological test scores indicated the effects of allopregnanolone on improving executive function, learning, and memory for patients with relatively preserved hippocampus and corpus callosum, while reducing psychological symptoms for patients with small hippocampi and amygdalae. The findings show the promise of allopregnanolone in improving cognitive functioning in patients with FXTAS and in partially alleviating some aspects of neurodegeneration. Further studies are needed to verify the efficacy of allopregnanolone for treating FXTAS.


Asunto(s)
Ataxia/tratamiento farmacológico , Síndrome del Cromosoma X Frágil/tratamiento farmacológico , Pregnanolona/uso terapéutico , Temblor/tratamiento farmacológico , Administración Intravenosa , Anciano , Ataxia/psicología , Encéfalo/diagnóstico por imagen , Encéfalo/efectos de los fármacos , Encéfalo/patología , Encéfalo/fisiopatología , Síndrome del Cromosoma X Frágil/psicología , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Pregnanolona/sangre , Resultado del Tratamiento , Temblor/psicología
13.
Biochim Biophys Acta ; 742(2): 285-94, 1983 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-6824690

RESUMEN

The triazine dyes, Cibacron blue F3GA and Procion red HE3B inhibited diaphorase activity of ferredoxin-NADP+ reductase, in a competitive manner with respect to NADPH. The Ki values were 1.5 and 0.2 microM, respectively. Binding of the dyes to the flavoprotein, as measured by difference spectroscopy, indicated an apparent stoichiometry of 1 mol dye/mol reductase and was prevented by NADP+ or high ionic strength. Chemical modification of a lysine residue and a carboxyl group at the NADP(H) binding site of the enzyme prevented complex formation with Procion red. Procion red showed a higher affinity for ferredoxin-NADP+ reductase than Cibacron blue. The Kd values were 1.9 and 5 microM, respectively. Once covalently linked to a Sepharose matrix, the triazine compounds specifically bind the flavoprotein. The interaction is partially electrostatic and partially hydrophobic. The enzyme can be eluted by high concentrations of salt or low concentrations of the corresponding coenzyme. The use of this affinity column allows the rapid purification of ferredoxin-NADP+ oxidoreductase from spinach leaves with good yields.


Asunto(s)
Colorantes/farmacología , Ferredoxina-NADP Reductasa/metabolismo , NADH NADPH Oxidorreductasas/metabolismo , Triazinas/farmacología , Cromatografía de Afinidad/métodos , Ferredoxina-NADP Reductasa/aislamiento & purificación , Cinética , Plantas/enzimología
14.
Plant Physiol ; 121(2): 471-8, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10517838

RESUMEN

The stability of chloroplastic glutamine synthetase (GS; EC 6.3.1.2) was investigated under photooxidative stress using wheat (Triticum aestivum L.) leaves, chloroplasts, and chloroplast lysates. Illuminated seedlings sprayed with the superoxide radical (O-(2)) propagator methyl viologen showed rapid GS decline dependent on MV concentration and exposure time. Degradation products of approximately 39 and 31 kD were detected when chloroplast lysates containing both stroma and thylakoids were illuminated in the presence of MV or H(2)O(2). In all cases, GS cleavage was prevented by the addition of the electron transport inhibitor 3-(3, 4-dichlorophenyl)-1,1-dimethylurea. Full protection against degradation could also be obtained by the incorporation of chelators or antioxidant enzymes. Maximal rates of degradation required the presence of transition metals and reducing compounds such as NADPH or dithiothreitol. Similar patterns of GS cleavage were obtained when seedlings were exposed to high doses of irradiation. The results indicate that chloroplastic GS is extremely prone to oxidative cleavage, and that reduced transition metals, presumably resulting from the destruction of iron-sulfur clusters by light-generated O-(2), play a crucial role in the degradation process. The physiological implications of GS lability to oxidative stress are discussed.

15.
J Frailty Aging ; 4(2): 74-9, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-27032048

RESUMEN

BACKGROUND: Low cognitive performance has been associated with a wide array of adverse health-related outcomes in elderly populations. Recently, the effect of vitamin D on cognition has been studied; however, its benefits are still controversial. Moreover, most studies have been carried out on North-American and European populations where vitamin D deficiency could represent a greater public-health issue when compared to Latin American ones. OBJECTIVE: To investigate the association between 25-OH-vitamin D and cognitive performance in Mexican community-dwelling elderly. DESIGN, SETTING AND PARTICIPANTS: Cross-sectional study sample of 331 community-dwelling elderly aged 70 and older, participating in the Mexican Study of Nutritional and Psychosocial Markers of Frailty. MEASUREMENTS: Serum 25-OH-vitamin D, cognitive performance as per the Mini-Mental State Examination (MMSE) and the IST (Isaacs Set Test), as well as several elements from the comprehensive geriatric assessment. RESULTS: Mean age of participants was 79.3 years (SD 5.9), 54.1% were women. The mean serum 25-OH-vitamin D level was 59.0 (SD 23.3) nmol/L while mean MMSE score was 22.3 (SD 3.4) and mean IST score was 37.1 (SD 9.1). Although 25-OH-vitamin D levels were lower across all the definitions of low cognitive perfomance, the difference between groups was not statistically significant in any of them. CONCLUSION: No association between 25-OH-vitamin D level and cognitive performance was found in this population of Mexican community-dwelling elderly. Further investigation is required in order to clarify its existence and if so, to delineate its characteristics.

16.
FEBS Lett ; 275(1-2): 102-6, 1990 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-2261976

RESUMEN

DNA polymerase activity was measured in chromoplasts of ripening tomato fruits. Plastids isolated from young leaves or mature red fruits showed similar DNA polymerase activities. The same enzyme species was present in either chloroplasts or chromoplasts as judged by pH and temperature profiles, sensitivities towards different inhibitors and relative molecular mass (Mr 88 kDa). The activities analyzed showed the typical behaviour of plastid-type polymerases. The results presented here suggest that chromoplast maintain their DNA synthesis potential in fruit tissue at chloroplast levels. Consequently, the sharp decrease of the plastid chromosome transcription observed at the onset of fruit ripening could not be due to limitations in the availability of template molecules. Other mechanisms must be involved in the inhibition of chromoplast RNA synthesis.


Asunto(s)
Cloroplastos/enzimología , ADN Polimerasa Dirigida por ADN/metabolismo , Plantas Comestibles/enzimología , Diferenciación Celular , Concentración de Iones de Hidrógeno , Técnicas In Vitro , Inhibidores de la Síntesis del Ácido Nucleico , Temperatura
17.
J Biochem Biophys Methods ; 10(1-2): 49-54, 1984 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-6520325

RESUMEN

A general procedure for the manual sequencing of peptides using the fluorogenic reagent O-phthalaldehyde (OPA) is described. The method can be applied in two different ways. One of them involves back hydrolysis of the anilinothiazolinones resulting from the Edman degradation of the peptide and subsequent detection of the free amino acids as OPA derivatives. The other is a subtractive analysis in which the amino acid composition of the remaining peptide is determined after each degradation cycle. The direct procedure can be coupled to the subtractive one in order to assure the accuracy of the sequence analysis. The method is fast and simple, and allows determination of 10 pmol of amino acid per cycle using standard reagents and instrumentation. Sensitivity can be greatly enhanced provided that ultrapure chemicals are employed. Small peptides (8-10 residues) were sequenced from 200 pmol sample, using a high-performance liquid chromatography assembly coupled to a fluorescence detector.


Asunto(s)
Aldehídos , Péptidos/análisis , o-Ftalaldehído , Secuencia de Aminoácidos , Cromatografía Líquida de Alta Presión , Microquímica/métodos
18.
Rev Esp Cardiol ; 50(1): 31-5, 1997 Jan.
Artículo en Español | MEDLINE | ID: mdl-9053944

RESUMEN

INTRODUCTION AND OBJECTIVES: Because left ventricular mass is associated with an increase in the risk of morbidity and mortality of cardiovascular diseases in the general population having the electrocardiogram as an accessible and inexpensive method for the diagnosis of left ventricular hypertrophy, we decided to calculate the sensitivity and specificity of 5 electrocardiographic criteria for the diagnosis of left ventricular hypertrophy and to compare the results of the original authors to ours. PATIENTS AND METHODS: 135 patients were evaluated; 46 patients were excluded by the following criteria: chronic obstructive pulmonary disease, complete left or right bundle branch block, cardiovascular ischemic disease or Wolf-Parkinson-White Syndrome. 89 patients remained and had an electrocardiogram performed applying the following criteria: Romhilt-Estes Point-Score system. Sokolow-Lyon (SV1 + RV5 or V6 > 3.5 mV) and (RaVL > 1.1 mV), Cornell and Rodríguez Padial. Left ventricular hypertrophy was defined by the Penn Convention Criteria. RESULTS: In our study we obtained the following results: a) Romhilt-Estes had a sensitivity of 12% and a specificity of 87%; b) Sokolow-Lyon (SV1 + RV5 or V6) had a sensitivity of 22% and a specificity of 79%; c) Sokolow-Lyon (RaVL) has a sensitivity of 18% and a specificity of 92%; d) Cornel had a sensitivity of 31% and a specificity of 87%, and e) Rodríguez Padial had a sensitivity of 82% and a specificity of 8%. There are similarities between our results and the authors's original ones. However, there are significant statistical differences between them (p < or = 0.01). CONCLUSION: Our conclusion is that these criteria have a low diagnostic value in the isolated interpretation of patients with left ventricular hypertrophy, and we need to integrate them with the whole medical history and physical examination.


Asunto(s)
Electrocardiografía/métodos , Hipertrofia Ventricular Izquierda/diagnóstico , Adulto , Electrocardiografía/normas , Femenino , Humanos , Hipertrofia Ventricular Izquierda/fisiopatología , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad
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