RESUMEN
Desmosomes are intercellular adhesive junctions and attachment sites for the intermediate filament (IF) cytoskeleton, prominent in tissues subject to high levels of mechanical stress such as the epidermis and heart. The obligate desmosomal constituent, plakoglobin (PG), is involved in coupling transmembrane desmosomal components with IFs. PG also contributes to intercellular adhesion through adherens junctions and has additional signaling roles. To date, two mutations in the gene encoding PG, JUP, have been described, and in both instances, patients harboring pathogenic mutations suffered from arrhythmogenic right ventricular cardiomyopathy with or without skin abnormalities. We describe homozygous nonsense mutation, p.S24X, and homozygous splice site mutation, c.468G>A, in the JUP gene that results in skin fragility, diffuse palmoplantar keratoderma, and woolly hair with no symptoms of cardiomyopathy. We show barely detectable levels of PG immunostaining in skin sections from patients harboring these mutations and show that an alternative AUG codon in p.S24X mRNA translates a 42-amino-acid N-terminal truncation. We conclude that PG is required for correct maintenance of skin integrity, and the absence of heart phenotype in patients suggests that aberrant PG expression does not compromise normal human heart development in children. Our findings provide new insight into the distinct roles that PG has in the epidermis and heart.
Asunto(s)
Cardiomiopatías/genética , Codón sin Sentido/genética , Desmoplaquinas/genética , Corazón/crecimiento & desarrollo , Homocigoto , Sitios de Empalme de ARN/genética , Enfermedades Cutáneas Genéticas/genética , Biopsia , Cardiomiopatías/fisiopatología , Niño , Preescolar , ADN Complementario/genética , Desmoplaquinas/fisiología , Femenino , Corazón/fisiología , Humanos , Lactante , Masculino , Técnicas de Amplificación de Ácido Nucleico , Fenotipo , Polimorfismo de Nucleótido Simple/genética , ARN Mensajero/genética , Piel/patología , Piel/ultraestructura , Enfermedades Cutáneas Genéticas/fisiopatología , gamma CateninaRESUMEN
Amycolatopsis sp. AB0, a copper resistant actinobacterium isolated from polluted sediments, has shown high copper specific biopsortion ability (25 mg g(-1)). Two approaches were used to confirm metal accumulation in growing cells of Amycolatopsis sp. AB0; we performed subcellular fractioning assays which showed that the retained copper was associated with the extra-cellular fraction (exopolymer, 40%), but mainly within the cells. Intracellular distribution of copper was: 86% in the cytosolic fraction, 11% at the cell wall and 3% associated with the ribosome/membrane fraction. Its copper bioaccumulation ability was corroborated by using silver enhanced staining of copper with the Timm's reagent technique, which has not been used to detect metal deposits in bacteria before. In addition, we constructed specific oligonucleotides for targeting genes coding for copper P-Type ATPases that could be involved in the copper uptake ability of this strain. A 607 bp DNA fragment was amplified and sequenced from Amycolatopsis sp AB0. BLAST search analysis showed 71% protein homology of the deduced sequence with a putative cation-transporting ATPase of Nocardia farcinica and 65% with a copper translocating ATPase of Mycobacterium flavescens. To our knowledge this is the first report of the presence of copper P-type ATPase genes in the Amycolotopsis genus.
Asunto(s)
Actinomycetales/metabolismo , Adenosina Trifosfatasas/genética , Proteínas Bacterianas/genética , Proteínas de Transporte de Catión/genética , Cobre/metabolismo , Actinomycetales/genética , Actinomycetales/ultraestructura , Adenosina Trifosfatasas/metabolismo , Secuencia de Aminoácidos , Proteínas Bacterianas/metabolismo , Proteínas de Transporte de Catión/metabolismo , ATPasas Transportadoras de Cobre , ADN Bacteriano/genética , Marcación de Gen , Microscopía Electrónica , Datos de Secuencia Molecular , Alineación de Secuencia , Homología de Secuencia de AminoácidoRESUMEN
Nevus psiloliparus is a distinct type of mesodermal nevus of the scalp characterized by absence or paucity of hair, and presence of an excessive amount of fatty tissue. It is considered a hallmark of encephalocraniocutaneous lipomatosis, a rare disorder comprising a variety of cutaneous, ophthalmologic, and neurologic defects. We report two infants with encephalocraniocutaneous lipomatosis with nevus psiloliparus on the scalp in close association with aplasia cutis congenita. This unusual association may be considered a further example of didymosis, for which we propose the term, didymosis aplasticopsilolipara.
Asunto(s)
Tejido Adiposo , Displasia Ectodérmica/diagnóstico , Nevo/diagnóstico , Dermatosis del Cuero Cabelludo/diagnóstico , Alopecia/etiología , Diagnóstico Diferencial , Displasia Ectodérmica/complicaciones , Femenino , Humanos , Lactante , Masculino , Nevo/complicaciones , Nevo/congénito , Dermatosis del Cuero Cabelludo/complicaciones , Dermatosis del Cuero Cabelludo/congénitoRESUMEN
Two siblings with familial cutaneous collagenoma syndrome had the essential clinical features of multiple skin-colored nodules on the trunk and upper arms. On light microscopy, histopathologic findings included excessive accumulation of dense, coarse collagen in the dermis. Elastic tissue stains demonstrated a proportionately diminished number of abnormal elastic fibers intermingled with the collagen bundles. A predominance of densely packed collagen bundles of normal morphology with a marked decrease in abnormal elastic tissue were the major ultrastructural features. The diagnosis was therefore confirmed to be connective tissue nevi of the collagen type. The differential diagnosis of connective tissue nevi disorders is delineated.
Asunto(s)
Enfermedades del Tejido Conjuntivo/patología , Enfermedades de la Piel/patología , Niño , Enfermedades del Tejido Conjuntivo/genética , Diagnóstico Diferencial , Hamartoma/patología , Humanos , MasculinoRESUMEN
The ultrastructural modifications of the respiratory tract of mice produced by the intranasally inoculated L. fermentum was evaluated. The genus Lactobacillus has been largely studied from the probiotic effect point of view in different ecological systems. Lactobacilli inoculated in 4 intranasal doses (1 x 10(9) CFU/dose) do not produce fundamental changes at the ultrastructural level in the organs of the respiratory tract studied. The most important finding was the presence of a cellular type with intracellular structures surrounded by membranes exhibiting electron dense paracristalline material parallel arranged.
Asunto(s)
Animales , Ratones , Lactobacillus , Mucosa Respiratoria , Administración Intranasal , Gránulos Citoplasmáticos/ultraestructura , Membranas Intracelulares , Ratones Endogámicos BALB C , Microscopía ElectrónicaRESUMEN
Niña de 10 años de edad, de raza indo-americana, con placas verrugosas orales de siete meses de evolución. El diagnóstico clínico de hiperplasia epitelial focal fue confirmado por microscopía electrónica. Se realiza la descripción de esta patología frecuente en comunidades indígenas de bajo nivel socioeconómico y su diagnóstico diferencial con otras patologías orales clínicamente similares
Asunto(s)
Humanos , Femenino , Hiperplasia Epitelial Focal/diagnóstico , Hielo Seco/uso terapéutico , Hiperplasia Epitelial Focal/patología , Hiperplasia Epitelial Focal/terapiaRESUMEN
Es bien conocido que el principal factor etiológico de la enfermedad periodontal es el depósito de placa bacteriana que al calcificarse da lugar a la formación del cálculo dental. El objetivo de este trabajo fue establecer con microscopía de luz, microscopía electrónica de barrido (MEB) y microscopía electrónica de transmisión (MET), cuáles son la estructuras que participan en la adhesión del cálculo a la superficie del diente. Se estudiaron 82 piezas con enfermedad periodontal avanzada, las cuales presentaban una significativa masa calcular adherida a la superficie cementaria. Las muestras se procesaron de acuerdo con las técnicas de rutina para microscopía de luz y microscopía electrónica de barrido, y la técnica de inclusión en resina Spurr para microscopía electrónica de transmisión. Al microscopio de luz se observó una delgada línea basófila de demarcación interpuesta entre el cálculo y la superficie dental. El MEB reveló la presencia de un material de naturaleza fibrilar dispuesto perpendicularmente a ambas superficies (cálculo y cemento) que actuaría como elemento responsable de tal adhesión. Al MET se comprobó que dicho material fibrilar corresponde a fibras colágenas con un patrón característico de periodicidad. En conclusión, el estudio óptico permitió el hallazgo de una zona homogénea continua en la interfase cálculo-diente. El estudio ultraestructural puso en evidencia que la íntima relación existente entre el cálculo y las irregularidades del cemento es atribuible a la firma adhesión que ofrecen las fibras colágenas entre estas dos superficies