RESUMO
Left ventricle non-compaction cardiomyopathy is currently considered as a well-defined individual entity. However, it includes a broad spectrum of clinical, radiological and pathophysiological findings. In this review we describe 3 different scenarios of this entity: an isolated case with severe left ventricle dysfunction, an "associated" case in a patient with previous atrial septum defect and pulmonary stenosis and finally, as a finding in a patient with a transient cerebrovascular ischemic attack. In the 2 last cases, both asymptomatic, morphological criteria of left ventricle non-compaction were found but, ventricular function was normal and cardiac-MRI showed no late gadolinium hyperenhancement. Periodical follow-up and familial screening were recommended. Natural history and prognosis factors of this disease are still not well known. Further and longer series of patients with this diagnosis are needed to completely define radiological criteria, clinical presentation and evolution.
La miocardiopatía no compactada está considerada actualmente como una entidad independiente y bien definida. Sin embargo, presenta un espectro amplio de hallazgos clínicos, radiológicos y fisiopatológicos. En la presente revisión describimos 3 escenarios clínicos diferentes de dicha entidad: un caso con disfunción ventricular severa, un caso como entidad «asociada¼ a una cardiopatía congènita en un pacientes con un defecto del septo interauricular previo y estenosis pulmonar, y finalmente, como un hallazgo casual en un paciente con un accidente cerebrovascular transitorio. En estos 2 últimos casos se encontraron criterios morfológicos de miocardiopatía no compactada con función ventricular normal y sin presencia de realce tardío de gadolinio en el estudio de cardio-RM. En todos ellos se recomendó estudio familiar. La historia natural y el pronóstico de esta anatomía patológica no son todavía del todo conocidos. Series mayores y seguimiento más largos son necesarios para definir completamente los criterios radiológicos, la presentación clínica y la evolución de esta fascinante entidad.
Assuntos
Adulto , Feminino , Humanos , Masculino , Adulto Jovem , Técnicas de Imagem Cardíaca , Miocárdio Ventricular não Compactado Isolado/diagnóstico , Imageamento por Ressonância MagnéticaRESUMO
Left ventricle non-compaction cardiomyopathy is currently considered as a well-defined individual entity. However, it includes a broad spectrum of clinical, radiological and pathophysiological findings. In this review we describe 3 different scenarios of this entity: an isolated case with severe left ventricle dysfunction, an "associated" case in a patient with previous atrial septum defect and pulmonary stenosis and finally, as a finding in a patient with a transient cerebrovascular ischemic attack. In the 2 last cases, both asymptomatic, morphological criteria of left ventricle non-compaction were found but, ventricular function was normal and cardiac-MRI showed no late gadolinium hyperenhancement. Periodical follow-up and familial screening were recommended. Natural history and prognosis factors of this disease are still not well known. Further and longer series of patients with this diagnosis are needed to completely define radiological criteria, clinical presentation and evolution.
Assuntos
Técnicas de Imagem Cardíaca , Miocárdio Ventricular não Compactado Isolado/diagnóstico , Imageamento por Ressonância Magnética , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
Infecciones murinas experimentales con un aislado venezolano de Trypanosoma evansi ocasionan cambios ma - cros copicos y ultraestructurales en el rinon de los ratones. La modificacion macroscopica se restringe a palidez progresiva del organo. Por su parte, las alteraciones ultraestructurales incluyen incremento del grosor de la membrana basal glomerular, asi como del espesor de la membrana basal de los tubulos contorneados proximales, cambios en la colocacion y el agrupamiento de las mitocondrias asociadas a la lamina basal, asi como extenso deterioro epitelial. Los tripanosomas intravasculares fueron detectados en la circulacion renal a partir de dia 9 post-infeccion. Se discute al respecto del dano glomerular, sugiriendo que las alteraciones submicroscopicas debilitarian la funcion tubular, contribuyendo mediante un proceso nefritico al desarrollo de una falla renal aguda que culminaria con la muerte del hospedador experimental. La significancia de los cambios ultraestructurales fue corroborada estadisticamente.
Murine experimental inoculations with a Venezuelan isolate of Trypanosoma evansi cause macroscopic and ultrastructural changes in the kidney of the infected animals. The macroscopic modifications are restricted to the progressive paleness of the organ. By its part, the ultrastructural alterations include thickness enlargement of the glomerular basal and the proximal tubule basal membranes, changes in the mitochondrial grouping and layout close to the basal membrane, as well as extensive epithelial damage. Intra vascu - lar trypanosomes were seen in the renal circulation from day 9 post-infection and on. The glomerular injury is discussed, suggesting that submicroscopic alterations could weaken the tubular function contributing through a nephritic process with the development of an acute renal failure culminating in the experimental host¡¦s death. The significance of the sequential increasing ultrastructural changes was statistically corroborated.
RESUMO
En este estudio investigamos los cambios ultraestructurales a corto y largo plazo provocados por la toxina botulínica tipo A inyectada a dosis sub-letales in vivo en el levator auris longus de ratones. La neurotoxina actuó temporalmente sobre los terminales nerviosos e indujo una parálisis generalizada que afectó la morfología de la preparación neuromuscular estudiada influyendo sobre: tamaño y complejidad de la terminación nerviosa, población vesicular, apariencia de las mitocondrias, fisonomía de las células de Schwann, desarrollo y distribución de los pliegues de la membrana postsináptica, y morfología de los núcleos de los diferentes elementos de la placa motora. Además, la cantidad de tejido conectivo endomisial aumentó significativamente con relación a los casos control, siendo estos cambios marcados en las primeras semanas. Entre los 20 y 25 días, período correspondiente al proceso de recuperación observamos terminales nerviosos de apariencia variable, unos completamente degenerados rodeados por restos de prolongaciones de células de Schwann y otros nuevos contactos caracterizados ultraestructuralmente por su pequeño calibre y población vesicular escasa, rodeadas parcialmente por la célula de Schwann, axones tempranamente mielinizados, pliegues sinápticos escasamente desarrollados. Sesenta días posteriores a la inyección, el axón terminal recobró su apariencia normal: las vesículas sinápticas llenaban el axoplasma, las mitocondrias exhibían crestas y densidades electrónicas de apariencia habitual. Se puede concluir que la toxina botulínica tipo A provoca fenómenos de desnervación en el nervio terminal y en los componentes de la placa motora. Las células de Schwann juegan un papel importante en la recuperación morfofuncional de los terminales nerviosos y en su degradación.
Assuntos
Animais , Camundongos , Placa Motora , Células Musculares , Toxinas Botulínicas Tipo A/toxicidadeRESUMO
We studied the short and long term ultrastructural changes produced by botulinum neurotoxin type A injected in vivo, at a sublethal dose, in mouse levator auris longus muscle. The neurotoxin had a temporary effect on nerve terminals which consisted in a generalized paralysis, that affected the following features of the neuromuscular sample's morphology: size of the nerve terminals, vesicle population, mitochondrial appearance, Schwann cell's morphology, development and distribution of post-synaptic membrane folds, and nuclear morphology of the different elements of the motor end plate. Besides, the amount of endomysial connective tissue was significantly greater compared to non-intoxicated cases, and these changes were more notorious during the first couple of weeks. 20 to 25 days after the injection, during the recovery phase, we observed nerve terminals with a variable appearance: some completely degenerated, enveloped by Schwann cell processes, and new contacts characterized ultrastructurally for their small size, scarce vesicles, partially enveloped by Schwann cells, early myelinized axons and barely developed synaptic folds. Sixty days after the injection, the axon terminal recovered its normal appearance: synaptic vesicles filled the axon's cytoplasm, and the mitochondria showed normal appearing cristae and electronic densities. We conclude that botulinum neurotoxin type A produces changes related to denervation of the nerve terminals and affects the motor end plate components. Schwann cells play an important role both in the morphofuntional recovery of nerve terminals and in their degradation.
Assuntos
Toxinas Botulínicas Tipo A/toxicidade , Fibras Musculares Esqueléticas/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Animais , Masculino , Camundongos , Microscopia Eletrônica , Fibras Musculares Esqueléticas/diagnóstico por imagem , Músculos do Pescoço/efeitos dos fármacos , Músculos do Pescoço/inervação , Músculos do Pescoço/ultraestrutura , Junção Neuromuscular/diagnóstico por imagem , Junção Neuromuscular/efeitos dos fármacos , Sinapses/ultraestrutura , UltrassonografiaRESUMO
Leishmania parasites are sensitive to peptides with antimicrobial and ion-channel inhibitory activity. Because scorpion venoms are rich sources of such peptides, the leishmanicidal effect of Tityus discrepans venom was investigated. A negative correlation between cell growth and venom concentration was observed for venom-treated cultures of Leishmania (L.) mexicana mexicana promastigotes; 50% growth inhibition was obtained at 0.4 microg/ml. Light microscopy showed rounded, highly vacuolated L. (L.) m. mexicana cells with impaired flagellar motion after 15 min of incubation at 35 microg/ml. Ultrastructural studies confirmed an intense cytoplasm vacuolation and also enlargement of the flagellar pocket. Survival rates for New World Leishmania promastigotes (75% venom effective concentration, microg/ml) obtained after acute (1 h) venom toxicity tests were: L. (L.) m. mexicana (2.3), Leishmania (V.) braziliensis (11.3), and Leishmania (L.) chagasi (56.2). Heat (90 degrees C) treatment of venom and fraction TdII abolished most of their leishmanicidal effect. Acute toxicity assays performed with Sephadex G-50 fractions indicated that leishmanicidal activity is associated with the venom lowest molecular mass components (2.8-7.4 kDa), as determined by MALDI-TOF mass spectrometry.
Assuntos
Leishmania braziliensis/efeitos dos fármacos , Leishmania mexicana/efeitos dos fármacos , Leishmania/efeitos dos fármacos , Venenos de Escorpião/farmacologia , Escorpiões/metabolismo , Animais , Leishmania/classificação , Leishmania/crescimento & desenvolvimento , Leishmania braziliensis/crescimento & desenvolvimento , Leishmania mexicana/crescimento & desenvolvimento , Testes de Sensibilidade Parasitária , Venenos de Escorpião/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
This ultrastructural study was undertaken to investigate the morphological changes which occur in the fast twitch gastrocnemius muscle of the reptile Iguana after nerve section. It was found that initial degenerative alterations appeared in muscle fibers two weeks after denervation and prograssed aling the two months of the investigative period. They consisted of disorganization of contractile and sarcotubular elements and the appearance of autophagic vacuoles with mitochondrial debris. However, even two months after nerve section some myofibrils and mitochondria looked normal. Our results suggest that although the general course of denervation atrophy in iguana gastrocnemius is sinilar to that in other twitch muscle of vertebrates, the chonology of the process shows that iguana fast twich skeletal muscle exhibit an intermediary position among the vertebrates in relation to their velocity of response to denervation