RESUMEN
Malaria, a common health problem in certain parts of the world, has a considerable morbidity and mortality. This work reports under electron microscopy studies serious ultrastructural kidney damage such as extensive cytoplasmic vacuolation, vesiculation and autophagic vacuoles in proximal tubular cells. A thickened endothelial wall on peritubular capillary, interdigitation disorganization and significant decrease of their number in some areas were detected. Swollen rough endoplasmic reticulum, swollen mitochondria, and parasitized erythrocytes were observed. Many epithelial cells exhibited cytoplasmic areas of autophagia and a myelin-like form. A tubular cell presented severe cytoarchitecture alterations. Abundant lipid droplets were noticed. Almost total loss of interdigitations, rough endoplasmic reticulum vesiculation, peritubular capillaries with endothelial cells thickened cytoplasm, papillary processes projected to the lumen, and an inflammatory infiltrate of macrophages were also observed. These ultrastructural kidney changes could cause, on the basis of their clinical and pathologic expressions, a fat accumulation, an acute temporary reversible glomerulonephritis, a chronic progressive irreversible glomerulonephritis, and an acute renal failure (ARF).
Asunto(s)
Glomérulos Renales/ultraestructura , Túbulos Renales Proximales/ultraestructura , Riñón/ultraestructura , Malaria/patología , Microscopía Electrónica de Transmisión/métodos , Plasmodium berghei/fisiología , Animales , Citoplasma/química , Citoplasma/ultraestructura , Modelos Animales de Enfermedad , Riñón/parasitología , Glomérulos Renales/parasitología , Túbulos Renales Proximales/parasitología , Lípidos/análisis , Malaria/transmisión , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
Biopsy specimens of cervico-scutular muscles obtained from animals injected with bee crude venom were prepared for electron microscopy studies. At 6 h from Apis mellifera venom injection, in mice under transmission electron microscopy, the muscular fibres presented different atrophy levels with increment of the intermyofibrillar spaces. Tubules and sarcoplasmic reticulum elements were altered, in some places only tubular fragments and an increment of the intermyofibrillar spaces were noticed as well as loss of fibre regularity and prominent triads. In subsarcolemma region, areas lacking myofibrils and mitochondria damages were observed. Muscular segmental necrosis and atrophy areas were observed. Neuromuscular junctions were altered. The number of synaptic vesicles was very variable and synaptic clefts showed irregularities. A decrease in the number and arrangement of the synaptic clefts, as well as free polysomes, suggesting regeneration processes, were also observed. The myelinic nerves exhibited in the axon or in the wall vacuolisation areas. The presence of severe muscular lesions, the finding of venom activities in the presynaptic region and the detection of damages in the neuromuscular junctions at different chronological stages of our experiments indicate that the bee venom is highly toxic for neuromuscular structures.
Asunto(s)
Venenos de Abeja/toxicidad , Abejas , Músculo Esquelético/efectos de los fármacos , Unión Neuromuscular/efectos de los fármacos , Nervios Periféricos/efectos de los fármacos , Animales , Venenos de Abeja/administración & dosificación , Inyecciones Intraperitoneales , Dosificación Letal Mediana , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica de Transmisión , Fibras Musculares Esqueléticas/efectos de los fármacos , Fibras Musculares Esqueléticas/ultraestructura , Músculo Esquelético/ultraestructura , Unión Neuromuscular/ultraestructura , Nervios Periféricos/ultraestructuraRESUMEN
Bee accidents incidence is underestimated because many people do not consult to the physicians. Here it is described for the first time the severe mice adrenal gland damage induced by Apis mellifera venom. Biopsy specimens were obtained from mice adrenal gland and after sample preparation observed in Hitachi H-7100 electron microscope. In this work the ultrastructural analysis showed, 6 h after injection, a non homogeneous smooth endothelial reticulum, and in some places loss of plasma membrane. The fenestrae spaces were bigger and detritus in the capillary lumen were observed. Erythrocytes were seen in a cortical cell. After 48 h of venom injection, expanded fenestrae were observed. Capillary basal membrane was interrupted. Myelin-like figures and autophagic vacuoles were noticed. Swollen smooth endoplasmic reticulum elements and endothelial unfolding to the light were seen. Moreover, swollen Golgi and mitochondria were observed, in some places forming myelinic-like figures. At 144 h after venom injection, widened spaces were noticed in capillary fenestrae. Cellular section showed swollen and lost smooth endoplasmic reticulum elements. Smooth endoplasmic reticulum tubules disappearance suggested non steroidogenesis. In conclusion, we suggest that some of the bee envenoming human clinical manifestations, as is observed in mice, are determined by suprarenal gland damage produced by toxins present in this venom.
Asunto(s)
Corteza Suprarrenal/efectos de los fármacos , Venenos de Abeja/toxicidad , Abejas , Corteza Suprarrenal/ultraestructura , Animales , Abejas/fisiología , Dosificación Letal Mediana , Masculino , Ratones , Ratones Endogámicos C57BL , Orgánulos/efectos de los fármacos , Orgánulos/ultraestructuraRESUMEN
In this ultrastructural study we examined skeletal muscle fibres from mice intraperitoneally inoculated with a sublethal dose of Crotalus vegrandis (rattlesnake) venom. The group of mice inoculated presented neurological symptoms characterised by respiratory failure and hind limbs paralysis. Skeletal muscle fibres showed different degrees of alterations. Most of them presented the characteristic pattern of necrosis in progress. Atrophied and hypercontracted fibres were frequently seen. Some atrophied and necrotic fibres showed several nucleoli-like bodies in the nucleus. In the atrophic and hypercontracted fibres, sarcoplasmic vacuolation and abnormal mitochondria with stacked cristae were observed. Areas of segmental necrosis were also frequently found. In connection with these altered muscle fibres, capillary abnormalities were detected. This study suggests that in envenomed mice respiratory failure symptoms may be related with muscle damage caused by Crotalus vegrandis venom components.
Asunto(s)
Venenos de Crotálidos/toxicidad , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/ultraestructura , Animales , Venenos de Crotálidos/administración & dosificación , Inyecciones Intraperitoneales , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica , Fibras Musculares Esqueléticas/efectos de los fármacos , Fibras Musculares Esqueléticas/ultraestructura , Músculo Esquelético/irrigación sanguínea , Atrofia Muscular/inducido químicamente , Atrofia Muscular/patología , NecrosisRESUMEN
In South America rattlesnake venom activities have not been entirely characterised. Some studies have shown haemorrhagic, myotoxic, and neurotoxic effects as manifestations of envenoming in experimental animals and humans. Biopsy specimens were obtained from liver and immediately fixed in situ and observed in Hitachi H-500 and H-7100 electron microscopes. In this work the ultrastructural analysis of experimental mice liver showed hepatocytes with increased lipid droplets content and significant vacuolation in areas of their cytoplasm limiting with the Disse space. Lysosomes and altered peroxisomes exhibiting a very dense electron content were also evident. Mitochondrial pleomorphism including cup-shaped and ring-shaped mitochondria were frequently found. The cristae were scarce or absent in the majority of mitochondria observed. The rough endoplasmic reticulum showed a preferentially disposition lining the outer mitochondrial membranes. In some section glycogen particles were scarce and lipofuchsin granules could be observed. Red blood cells showed endothelial cell adherence and, in many instances, the liver sinusoids were observed plugged with aggregated red blood cells. In conclusion, using an animal model that probably correlates well with the pathological effects found in envenomed humans, we have shown the severe hepatocellular alterations caused by this venom.
Asunto(s)
Venenos de Crotálidos/toxicidad , Crotalus , Hígado/patología , Animales , Hígado/ultraestructura , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía ElectrónicaRESUMEN
As liver can be an important target organ in malaria, we performed an ultrastructural study of hepatic alterations in the final stage of Plasmodium berghei infection in mice. Significant hepatocyte abnormalities were found. An elevated number of cells showed mitochondria with a high electron-dense matrix and multiple changes in shape and size, alterations in the structure of Golgi complex, swelling and disorganisation of both rough and smooth-surfaced endoplasmic reticulum, differently shaped peroxisome nucleoids, and disappearance of glycogen granules. In other areas the hepatocytes were significantly altered with diminished microvilli and exhibited myelin-like figures, autophagic vacuoles, abundant lipid droplets, and swollen mitochondria in their cytoplasm. Necrotic and atrophied hepatocytes with scarce microvilli in the Disse space and biliary canaliculi could be seen. Parasitised red blood cells and parasite debris were found inside degenerated hepatocytes. Alterations were also noticed in microvasculature, including thickened endothelial cells with swollen mitochondria, lysosomes and autophagic vacuoles in their cytoplasm. Our results demonstrate that hepatocyte damage is an important finding associated with the advanced stages of P. berghei malarial infection, which may lead to liver dysfunction in this disease.
Asunto(s)
Hígado/ultraestructura , Malaria/patología , Plasmodium berghei , Animales , Modelos Animales de Enfermedad , Hígado/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BLRESUMEN
The ultrastructural study of adrenal cortex from Plasmodium berghei infected mice showed different degrees of capillary wall alterations including disruption and widening of the fenestrae, capillaries packed with parasitized erythrocytes, necrosis of cortical cells, parasitized erythrocytes outside capillaries and in some instances inside cortical cell cytoplasm. Lymphocytes were also observed in degenerated cortical cells. Our results suggest that adrenal cortex lesions may be relevant in the etiopathogenesis of severe malaria.