Beta-glucuronidasa urinaria: Influencia del tiempo de conservación / No disponible

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Descargas repetitivas complejas en una miopatía mitocondrial / Complex repetitive discharges in a mitochondrial myopathy

Mujer de 54 años de edad estudiada por debilidad crónica, atrofia muscular y elevación de creatin Kinshasa en sangre. El EMG de musculatura proximal de miembros superiores e inferiores reveló se registraron numerosas descargas repetitivas de potenciales de unidad motora polifásicos con amplitudes y frecuencias de disparo constantes, estaban integradas por 6 potenciales de fibra simple con un “jitter” entre sus diferentes componentes inferior a 5 µseg. Que sepamos, no han sido descritas descargas repetitivas complejas de estas características en miopatías mitocondriales del hombre, aunque si han sido referidas en el perro

A 54 year old woman was studied in our lab because chronic weakness, limb-girdle muscular atrophy and increased blood CK level. Electromyography assessment of proximal muscles in arms and legs revealed complex repetitive discharges with a very low interpotential jitter lesser than 5 µseg, further indicating the absence of end plate activity in their causation. Then, they are thought to originate form spontaneous activity in a single muscle fiber which activates one or more adjacent muscle fibre ephaptically. Ephaptic transmission from fibre to fibre in skeletal muscle is ordinarily prevented by the absence of adjacent simultaneously depolarizing muscle fibres, because of the pseudorandom nature of the distribution of the motor unit. When this relation is disturbed by reorganization of the motor unit in neurogenic and, to a lesser extent, in cronic myopathic diseases, cross-firing of adjacent muscle fibres is more likely. In our knowledge, this is the first time that complex repetitive discharges have been found in a human mitochondrial myopathic although they have been yet reported in sheepdog littermates

Urinary beta-glucuronidase in renal cell carcinoma.

The aim of the paper was to study the urinary beta-glucuronidase activity in 30 patients with renal cell carcinoma (RCC), histopathologically proven after surgery, and 32 healthy subjects taken as controls. Classification of patients was done using the TNM system. A statistically significant increase (p < 0.01) in this enzyme was found in RCC patients, without relation to the changes in the urinary sediment (hematuria, pyuria, bacteriuria) or tumor dissemination. Urinary beta-glucuronidase is a useful marker in the diagnosis of malignant renal tumors.