Paradoxo do cálcio - o que temos a temer? / The calcium paradox - What should we have to fear?

O paradoxo do cálcio foi pela primeira vez citado em 1966 por Zimmerman et al. A partir daí, ganhou grande interesse por parte da comunidade científica internacional devido ao fato da ausência do íon cálcio produzir na célula muscular cardíaca dano semelhante à lesão de isquemia-reperfusão. Apesar de não serem conhecidos todos os mecanismos envolvidos no processo da lesão celular no paradoxo do cálcio, a conexão intercelular mantida somente pelo nexus parece ter papel chave na fragmentação celular. A adição de pequenas concentrações de cálcio, bloqueadores de canal de cálcio, hiponatremia ou hipotermia são importantes para evitar que haja lesão celular no momento da reperfusão com soluções com concentração fisiológica de cálcio.

The calcium paradox was first mentioned in 1966 by Zimmerman et al. Thereafter gained great interest from the scientific community due to the fact of the absence of calcium ions in heart muscle cells produce damage similar to ischemia-reperfusion. Although not all known mechanisms involved in cellular injury in the calcium paradox intercellular connection maintained only by nexus seems to have a key role in cellular fragmentation. The addition of small concentrations of calcium, calcium channel blockers, and hyponatraemia hypothermia are important to prevent any cellular damage during reperfusion solutions with physiological concentration of calcium.

Heart injury following intestinal ischemia reperfusion in rats is attenuated by association of ischemic preconditioning and adenosine

PURPOSE: To investigate the effect of ischemic preconditioning (IPC) and adenosine as strategies to protect cardiac injury caused by intestinal IR in rats, based on increasing in adenosine bioavailability and improvement of cell energy state by IPC. METHODS: Male Wistar rats were submitted to 60 minutes of intestinal ischemia and 120 minutes of reperfusion. Intravenous injections of saline or Adenosine (AD) was administered five minutes before ischemia, five minutes before reperfusion and after 55 minutes reperfusion. Cardiac samples were obtained, fixed in formalin solution, embedded in paraffin, and sections of 5 μm were stained by hematoxylin-eosin. Histological analysis of myocardium was performed according occurrence of necrosis signs: piknosis, band contraction, eosinophilic cytoplasm, karyorrhexis and vacuolization (score - zero to 5). RESULTS: The groups submitted to ischemia alone (I=4.0), and reperfusion (IR=4.5) showed highest level of lesion compared to the others (I+IPC=3.3, IR+IPC=3.6, I+AD=3.0, IR+AD=3.8). The most interesting result was association of IPC and AD in IR model (IR+IPC+AD=1.2, p=0.002), showing preservation of the heart tissue, with fibers showing typical cross-striations and nuclei characteristics. Rare and small areas of tissue necrosis was observed and suggestion of capillaries congestion. CONCLUSION: Intestinal ischemia reperfusion promotes cardiac tissue injury. Ischemic preconditioning in association with adenosine is an efficient strategy to protect the heart against ischemia and reperfusion injury. .

Polimorfismos del gen de apolipoproteína E y polimorfimo Pro12Ala del gen PPARy-2 en niños pre-puberes con factores de riesgo cardiometabólicos / Apolipoprotein E gene polymorphisms and Pro12Ala polymorfphism of PPARy-2 gene in children with risk factors to cardiometabolic disease

La resistencia a la insulina es muy frecuente en niños y adolescentes obesos, la cual conlleva a un significativo riesgo de desarrollar enfermedades cardiometabólicas causadas por la combinación de factores genéticos y factores asociados al estilo de vida. Evaluar la relación entre los polimorfismos del gen ApoE y el polimorfismo Pro12Ala del gen PPARγ2 en niños pre-púberes con factores de riesgo cardiometabólicos. Población y Métodos: Se evaluaron 141 niños (CANIA y Hospital “JM de los Ríos”), de los cuales 46 tienen obesidad, 33 hipercolesterolemia, 30 resistentes a la insulina (RI) y 32 controles. Se determinó colesterol total y fracciones, triglicéridos, glucosa, insulina e índice HOMA; se realizó extracción de ADN y análisis de los polimorfismos. La distribución de la frecuencia del alelo ε4 del gen de ApoE fue: 10,9% obesos, 7,6% hipercolesterolémicos, 18,3% RI y 4,6% controles. La frecuencia del polimorfismo Pro12Ala fue de 6,4% en la población estudiada. En los niños obesos e hipercolesterolémicos se observó aumento de colesterol total, LDL-c y triglicéridos asociados con la presencia del ε4; en el grupo con RI, se encontró que existen diferencias estadísticamente significativas entre el alelo ε4 con respecto al grupo control, lo que refiere que puede haber una relación clínica importante entre la presencia del alelo y el desarrollo de la enfermedad. No se encontró relación entre el polimorfismo Pro12Ala del gen PPARγ2 con factores de riesgo cardiometabólico. La presencia de varios polimorfismos en un mismo individuo podría estar asociada a factores de riesgo para enfermedad cardiometabólica

Insulin resistance (IR) is very frequent in children and adolescents obeses, which could contribute significantly in the development of cardiometabolic diseases, this could be associated to a combination of genetics factors and life’s style. Aim: To evaluate the relationship between ApoE gene polymorphisms and PPARγ2 gene Pro12Ala polymorphisms with risk factors to cardiometabolic disease in children. Population and Materials: 141 children (CANIA and Hospital “JM de los Ríos”), 46 with obesity, 33 with hypercholesterolemia, 30 with IR and 32 normal subjects. Total cholesterol and fractions, glucose, insulin and triglycerides were measured; also it was determinated the polymorphism genes on each patient. Results: The distribution of the frequency of the allele E4 of the ApoE gene were: 10, 9% obese, 7,6% hypercholesterolemia, 18,3% IR and 4,6% on normal subjects. The frequency of Pro12Ala polymorphism were up to 6,4% on the total subjects in the study. In the obese and hypercholesterolemic groups we found an increase of the total cholesterol, LDL-c and triglycerides, associated with the presence of allele ε4. In children with IR we got a significant difference of the presence of allele ε4 compared with the control group, which means that this allele could be related with the development of thedisease. It was not found a relation between the Pro12Ala of PPARγ2 gene and the development of obesity, hypercholesterolemia and insulin resistance in children. The presence of several polymorphisms in a same individual could be associated with risk factors to cardiometabolic disease

Hypoxia/reoxygenation-induced myocardial lesions in newborn piglets are related to interindividual variability and not to oxygen concentration

OBJECTIVE: Evaluation of myocardial histological changes in an experimental animal model of neonatal hypoxiareoxygenation. METHODS: Normocapnic hypoxia was induced in 40 male Landrace/Large White piglets. Reoxygenation was initiated when the animals developed bradycardia (HR <60 beats/min) or severe hypotension (MAP <15 mmHg). The animals were divided into four groups based on the oxygen (O2) concentration used for reoxygenation; groups 1, 2, 3, and 4 received 18%, 21%, 40%, and 100% O2, respectively. The animals were further classified into five groups based on the time required for reoxygenation: A: fast recovery (<15 min); B: medium recovery (15-45 min); C: slow recovery (45-90 min); D: very slow recovery (>90 min), and E: nine deceased piglets. RESULTS: Histology revealed changes in all heart specimens. Interstitial edema, a wavy arrangement, hypereosinophilia and coagulative necrosis of cardiomyocytes were observed frequently. No differences in the incidence of changes were observed among groups 1-4, whereas marked differences regarding the frequency and the degree of changes were found among groups A-E. Coagulative necrosis was correlated with increased recovery time: this condition was detected post-asphyxia in 14%, 57%, and 100% of piglets with fast, medium, and slow or very slow recovery rates, respectively. CONCLUSIONS: The significant myocardial histological changes observed suggest that this experimental model might be a reliable model for investigating human neonatal cardiac hypoxia-related injury. No correlation was observed between the severity of histological changes and the fiO2 used during reoxygenation. Severe myocardial changes correlated strictly with recovery time, suggesting an unreported individual susceptibility of myocardiocytes to hypoxia, possibly leading to death after the typical time-sequence of events.

Aneurisma aorta torácica y falla cardíaca manejado con transplante cardíaco: descripción de un caso clínico / Aorta thoracic aneurysm and cardiac failure treated with cardiac transplant: description of a clinical case

Alrededeor de un 25% de aneurismas aórticos degenerativos afectan a la aorta torácica. En la mayoria de los casos afectan al arco y a la aorta desendente, a diferencia de los luéticosque tienen mayor frecuencia en aorta ascendente. A veces toda la aorta es estásica presentando multiples dilataciones que se extienden a aorta abdominal, dando lugar a aneurisma toracoabdominales. Existen factores predisponentes como la edad, hipertensión sistémica arterial (HTA), anomalias congénitas de la válvula aórtica, transtornos hereditarios del sistema conectivo, traumáticos y otros. Afecta a pacientes entre la quinta y la séptima décadas de la vida, siendo más frecuente en varones (3:1). En menores de 40 años la frecuencia es similar en ambos sexos, debido a la mayor frecuencia en mujeres durante el trecer trimestre del embarazo. La HTA es encontrada en el 80% de los casos, siendo el segundo factor predisponente en importancia.

Around 25% of degenerative aortic aneurysms affect the thoracic aorta. In the majority of cases they affect the arch and the descending aorta, unlike luetic aneurysms, which are more frequent in the ascending aorta. Sometime the entire aorta is in a state of stasis, presenting multiple dilatations that extend to the abdominal aorta giving rise to thoracoabdominal aneurysms. There are predispositional factors, among them systemic arterial hypertension (SAH), congenital anomalies of the aortic valve, hereditary connective system disorders and traumatisms. This condition affects patients in their 50s to 70s and is most frequent in males (3:1). In the under-40s, frequency is similar in both sexes, owing to the higher frequency among women during the third trimester of pregnancy. SAH is found in 80% of cases, being the second most important predispositional factor.

Achados ecocardiográficos em crianças com sopro "inocente" / Echocardiographic findings in children with innocent murmur

OBJETIVOS: Avaliar a freqüência de alterações ecocardiográficas em pacientes com diagnóstico de sopro "inocente". Métodos. Estudo transversal de uma amostra de 166 pacientes com diagnóstico de sopro "inocente" avaliados no ambulatório de Cardiologia Pediátrica do Instituto de Cardiologia/Fundação Universitária de Cardiologia, um serviço terciário de referência, durante o período de 3/12/2001 a 2/12/2002. Todos os pacientes realizaram anamnese, exame físico, eletrocardiograma e ecocardiograma. Foram estimadas as probabilidades pós-teste de exame clínico considerando o ecocardiograma como padrão ouro. Resultados. Dos 166 pacientes estudados, 11 apresentaram alguma alteração ao ecocardiograma: estenose pulmonar leve (4), forame oval patente (2), aorta bicúspide (2), comunicação interatrial (1), insuficiência aórtica mínima (1), comunicação interventricular mínima (1). A probabilidade pós-teste negativo, ou seja, a probabilidade de lesão cardíaca com diagnóstico de sopro "inocente" foi de 6,6 por cento. Conclusão. Em ambulatório especializado, é alta a proporção de alterações ecocardiográficas em pacientes com diagnóstico de sopro "inocente". Estes achados podem não estar relacionados à presença de sopro, como o forame oval patente e a aorta bicúspide. No entanto, levantam a questão da indicação de ecocardiograma considerando, por um lado, o baixo risco das lesões detectadas e, por outro, o caráter resolutivo de um ambulatório de referência.

Cellular mechanism of heart injury in the early stage of crush injury in rats / 法医学杂志

OBJECTIVE@#To study cellular mechanism of cardiomyocytes injury in the early stage of crush injury by observing some effects of crush injury rat sera on cultured neonatal rat cardiomyocytes.@*METHODS@#One to three days old neonatal rat cardiomyocytes were cultured in vitro and some effects of crush injury rat sera on beating rate, cell surface area, total protein content, 3H-Leu incorporation, intracellular calcium concentration ([Ca2+]i) and Fos protein expression were observed in cultured rat cardiomyocytes.@*RESULTS@#Compared with normal rat serum group, crush injury rat sera decreased beating rate(beats/min) of cardiomyocytes from 88.3 to 26.4, cell surface area, total protein content, 3H-Leu incorporation, [Ca2+]i (nmol/L) and PI of Fos protein expression were increased.@*CONCLUSION@#Crush injury rat sera suppress cell beating, increase intracellular calcium, induce Fos protein synthesis and cause cell hypertrophy, which may cause cardiac injury in the early stage of rush injury.

The sudden cardiac death in negative autopsy / 法医学杂志

The advancement of studies about the molecular biology and electronic physiology on sudden cardiac death was summarized in this article, including particularly cardiac concussion(commotio cordis), congenital long QT syndrome, and Brugada syndrome which probably resulting in fatal arrhythmia and sudden cardiac death. These corpses of fatal functional disorders often show the results of negative autopsy without obvious organic pathological changes. So when come across negative autopsy the medical examiner and the pathologist should be careful to investigate the inductive cause of sudden death, the history of disease, and the family history, then to rule out the possibility of the above disorders.

Lesiones cardiacas asociadas a traumatismo craneotorácico / Cardiac lesions associated to craniothoracic trauma

Las lesiones cardiacas por traumatismo son poco frecuentes y se presentan con mayor frecuencia cuando éste es torácico-abdominal. En el Hospital General de Coyoacán Xoco del Departamento del Distrito Federal, se estudiaron 100 necropsias médico-legales, con características de traumatismos craneotorácicos. Se observaron 11 casos con lesiones cardiacas francas sin aparentes lesiones torácicas. Las lesiones cardiacas asociadas a traumatismo craneotorácico son poco frecuentes en las necropsias. Se obtuvieron datos generales de la averiguación previa de los casos estudiados: tipo de traumatismo, edad, sexo, tiempo de evoluación en los casos de internamiento y alcoholismo, entre otros. Se correlacionaron los hallazgos macroscópicos con el daño cardiaco observado. Se registraron ocho contusiones pericárdicas y tres endocárdicas, ocho endocarditis no bacterianas, cinco trombosis intramurales de la aurícula derecha y tres casos de trombosis de la coronaria derechas, de los cuales uno presentaba trombosis multiorgánica. Se discute el mecanismo de la lesión cerebral con la asociación a lesiones cardiacas sin daño torácico directo, con diferentes factores que pudieran participar en el mecanismo del daño

Traumatic left ventricular aneurysm

Cardiac ventricular aneurysms are by large ischaemic and tend to develop following a transmural myocardial infarction. In the minority of cases, the cause may be congenital, infective, traumatic or idiopathic. While postinfarction ventricular aneurysms and those which follow cardiac surgery are common, traumatic aneurysms after accidental trauma are rare. We report a case of a true left ventricular aneurysm caused by a bullet injury