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The cell response of human HepG2 cells exposed to hypothermia with rewarming was analyzed. Ultrastructural findings in hypothermic stressed cells showed swollen mitochondria, dispersed chromatin, vacuoles and ring-shape nucleolar reorganization. These changes were coupled with significative differences in the induction of Hsp60, inducible Hsp70 and monomeric Hsf1 in all treated samples, but not in Hsc 70 expression. Cellular response to hypothermia could be associated with the synergistic induction of Hsp expression.

En este trabajo se analizó la respuesta celular de células HepG2 expuestas a hipotermia con posterior recuperación. Los hallazgos ultraestructurales en células sometidas a estrés hipotérmico incluyeron mitocondrias edematizadas, núcleos picnóticos, vacuolas y reorganización nucleolar en forma de anillo. Tales cambios están relacionados con diferencias significativas en la inducción de la expresión de Hsp60, Hsp70 inducible y Hsf 1 monomérico en todas las muestras tratadas, pero no de Hsc70. La respuesta celular a la hipotermia puede ser relacionada con la inducción sinergística de las Hsp.

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The cell response of human HepG2 cells exposed to hypothermia with rewarming was analyzed. Ultrastructural findings in hypothermic stressed cells showed swollen mitochondria, dispersed chromatin, vacuoles and ring-shape nucleolar reorganization. These changes were coupled with significative differences in the induction of Hsp60, inducible Hsp70 and monomeric Hsfl in all treated samples, but not in Hsc 70 expression. Cellular response to hypothermia could be associated with the synergistic induction of Hsp expression.

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In the present study, we compared the cell damage response in skeletal and cardiac muscle tissue when exposed to doxorubicin. This was carried out by means of a less invasive informative substitute to endomyocardiac biopsy based on Hsp70 immunodetection and a subcellular analysis of the nucleolus. Male Sprague Dawley rats (62 g body weight) were randomly distributed into 3 group, the control and doxorubicin I and doxorubicin II groups, in which 15 and 25 mg/kg body weight of doxorubicin (0.1 ml, i.v.) was administered, respectively. After 15, 30, 45 and 60 minutes, portions of the left and right ventricle wall and interventricle wall, together with skeletal muscle from the posterior and anterior member, were prepared for Hsp70 immunodetection by Western blot analysis and ultrastructural study using the thin cut technique. Differential cell response between the control and treated groups was observed in Hsp70 immunodetection and at the subcellular level. In the control group, the Hsp70 recognition levels and typical normal nucleolar morphology were similar, while the treated groups showed variable-dependent Hsp70 recognition and segregation of nucleolar components, forming ring-like figures of a variable-independent nature. Comparison of cardiac and skeletal muscle tissue cell response to doxorubicin toxic aggression revealed parallelism in terms of Hsp70 accumulation in certain regions of both tissues (15 mg/kg body weight of doxorubicin), which suggests that replacing endomyocardiac biopsy analysis with skeletal muscle analysis may be a safe option.

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This study examined Hsp70 accumulation and the subcellular characteristics of liver and lung when exposed to ethanol (EtOH), with and without L-carnitine protection. Female Sprague-Dawley rats, 150-200 g body weight, were randomized into four groups: Control (CON), Alcohol (ALC), L-carnitine (CAR) and Alcohol-L-carnitine (ALC-CAR). EtOH was administered per os at a dose of 4 g/kg body weight (1 ml) daily for 4 weeks. Before alcohol intake, an oral dose of 500 mg/kg body weight of L-carnitine was also administered to the ALC-CAR group. The liver and lung samples were subjected to Hsp70 Western blot and ultrastructural analysis. The Hsp70 accumulation was higher in the liver than in the lung samples. Hepatic Hsp70 accumulation was similar for all groups in contrast to lung, where the Hsp70 accumulation depends on the group studied. The ultrastructural results showed lung but not liver alterations, evidencing a stressful condition and subsequent cellular injury for lung tissue but not for liver. The ALC-CAR group showed less lung damage than the non-protected group and resembles the general appearance of the CON and CAR groups. EtOH intoxication induced differential cellular response in liver and lung in a dose and tissue dependent manner. L-carnitine seems to reduce lung EtOH-induced subcellular damage. The promotion of heat shock or stress proteins might represent one of the mechanisms involved that need to be further investigated.

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To understand hypothermia as a stress condition we determined the expression and localization of Hsp70 under hyperthermic and hypothermic stress in human hepatoma HepG2 cells. Western blot analysis indicates that there was a statistically significant increase of Hsp70 expression under thermal stresses. Immunohistochemically, the distribution of inducible Hsp70 in stressed cells showed a granular pattern mostly in the cytoplasm. At subcellular level, Hsp70 was localized in the nucleus, vacuoles, cytoskeletal components and dispersed throughout the cytoplasm. Accumulation of Hsp70 in cells under hypothermia could be related to restitution of cell equilibrium modified by this thermal stress condition. The protective effect of hypothermia could be associated with promotion of Hsp expression. We suggest that hypothermia is a stress capable of inducing Hsp70 expression in human HepG2 cells.

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Se estudiaron 100 casos de niños y jóvenes, menores de 20 años, portadores de enfermedades del músculo cardíaco autopsiados en el Instituto Anatopatológico. La distribución de los casos de acuerdo a la clasificación de la Organización Mundial de la Salud (1984) reveló que el 48 por ciento eran miopatías específicas del miocardio y el 32 por ciento, cardiomiopatías. Fueron más frecuentes: las miocardiopatías asociadas a lupus eritomatoso diseminado (21/100); las miocarditis (agudas y crónicas de diversas atiología),(20/100) y las miocardiopatías dilatadas (18/100). Se describieron las características macroscópicas del patrón ventricular izquierdo y del endocardio en cada grupo. Se señalaron los aspectos histopatológicos más relevantes del compartimiento miocítico y de la matríz extracelular en cada tipo analizado. En el estudio se incluyeron: casos de fibroelastosis endocárdica (17/100); miocardiopatía hipertrófica (12/100); cardiomiopatía histiocitoide (3/100); enfermedad de pompe (3/100); miocardiopatía mitocondrial (1/100) y asociados a esclerodermia (1/100) y a enfermedad de Duchenne (1/100)

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The ultrastructural alterations in ventricular capillary endothelia of chick embryo heart treated with Adriamycin (ADRIA) are discussed. White-Leghorn chicken eggs on the third day of incubation (stage 18), were injected through the egg shell with 1 ml of ADRIA 5, ug/egg. Eggs were reincubated until day 15 (stage 41-42), at which time the embryos were sacrified and their hearts removed. Controls were injected with equal volume of saline solution. Unlike the controls, ADRIA treated embryonic ventricular capillary endothelia exhibited marked evidences of vascular damage. An apparent reduction of the cytoplasmic surface area of the abnormally dark and smooth endothelial cells was observed. Capillary endothelial alterations also included cell vacuolization, absence of cytoplasmic endothelial cell proyections and cytoplasmic blebs along capillar endothelial surface, most prominently along the free cell surface or lumen. The comparison of the ultrastructural characteristics between control and ADRIA-treated embryonic heart, may confirm ADRIA cardiotoxic effects during cardiogenesis. Capillary endothelium may be an alternative target of ADRIA and in appears likely that drug toxic effect may promote vascular damage

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Se estudiaron morfológicamente quince casos de Fibroelastosis endocárdiaca (FEE) del material de 64 autopsias de enfermedades del músculo cardíaco infantiles, practicadas en el Instituto Anatomopatológico de la Universidad Central de Venezuela. Diez casos resultaron de FEE primaria y cinco de secundaria. Las edades oscilaron entre 3 y 36 meses. Todos los casos fallecían con insuficiencia cardíaca refractaria. Se hizo énfasis en los hallazgos patológicos miocárdicos de las FEE primarias. Las alteraciones de las fibras miocárdicas fueron: Hipertrofia y atrofia focal con alteraciones nucleares, desarreglo celular, fibrosis interticial y degeneración hidiopática celular subendocárdica. Todas estas lesiones fueron discretas y no explican claramente la disfunción ventricular severa en estos casos. La posibilidad de que los cambios endocárdicos sean secundarios a alteracioes metabólicas es sugestiva dado los buenos resultados obtenidos con el tratamiento con L-carnitina en series estudiadas. La importancia de la biopsia endomiocárdica en casos sospechosos de FEE radica en la mejor comprensión de la etiopatogenia y tratamiento de esta enfermedad

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