Efetividade do tratamento endodôntico em sessão única x múltiplas sessões na periodontite apical pós-tratamento: sinais e sintomas; carga microbiana; níveis de endotoxinas e ácido lipoteicóico e volumetria da destruição óssea periapical por TCFC / Effectiveness of one-visit and two-visits endodontic treatment in posttreatment apical periodontitis: signs and symptoms; microbial load; endotoxin and lipoteichoic acid levels and bone destruction analysis by CBCT in 18-months follow-up

Os objetivos deste estudo foram: a) avaliar o sucesso clínico e por tomografia computadorizada de feixe cônico (TCFC) após 18 meses do retratamento em sessão única (RU) e múltiplas sessões (RM); b) monitorar carga (UFC/mL) e perfil microbiano; níveis de endotoxinas (EU/mL) e de ácido lipoteicóico [LTA (pg/mL)] em dentes com periodontite apical pós-tratamento (PAPT) submetidos a RU e RM; c) comparar a sintomatologia pós-operatória pela escala visual analógica de dor (EVA) em RU e RM; d) comparar os tratamentos quanto à redução de UFC/mL, EU/mL, LTA (pg/mL) e a volumetria da lesão periapical (LP) e) avaliar as correlações e associações entre os dados obtidos no estudo. Seguindo critérios de inclusão e não-inclusão, foram selecionados 40 dentes com PAPT, divididos em dois grupos: RM e RU. Os pacientes foram submetidos à TCFC. Foram realizadas coletas do conteúdo do canal radicular: após remoção do material obturador (S1), após preparo biomecânico (PBM) (S2) e após MIC (S3). Ao final da sessão, foi fornecida a EVA para avaliação da sintomatologia dolorosa apresentada nos períodos de 24hs, 48hs e 7 dias. O conteúdo dos canais radiculares foi avaliado por cultura microbiológica, perfil microbiano por Checkerboard DNA-DNA hybridization, níveis de endotoxinas pelo teste Lisado Amebócito de Limulus e de ácido lipoteicóico pelo ensaio de ELISA. Foi realizada a volumetria da destruição óssea periapical inicial e final por TCFC pelo software ITK snap. Os dados foram analisados estatisticamente. Os níveis de UFC/mL, EU/mL e LTA (pg/mL) diminuíram após o PBM, havendo a manutenção dos mesmos após o uso de MIC (p>0,05). As coletas apresentaram valores iniciais (S1) maiores que os residuais (antes da obturação) para os parâmetros avaliados. Quanto aos valores residuais, foram encontrados maiores valores de UFC/mL em RM e menores valores de LTA no mesmo grupo (p<0,05); porém sem diferença entre os grupos RU e RM quanto aos valores residuais de EU/mL. Os micro-organismos Gram-negativos mais encontrados foram o F. nucleatum, C. rectus, C. gingivalis, P. gingivalis, P. intermedia e L. buccalis, sendo os Gram-positivos: E. faecalis, E. faecium, S. constellatus e S. mitis. Não houve diferença entre os grupos RU e RM quanto à sintomatologia pósoperatória (p>0,05) pela EVA. O volume inicial das LP variou de 10 a 470 mm³, sendo que o final variou de 0 a 48 mm³. Houve redução da média dos volumes de 84,71% em RU e de 90.56% em RM, sendo esta redução significante em ambos os grupos (p< 0,0001), mas sem diferença estatística entre eles (p=0,9117). No período de 18 meses após o retratamento endodôntico não houve diferenças na regressão das lesões e análise dos demais sinais e sintomas entre RU e RM(AU)

This study aimed to: a) evaluate the success rates of one-visit (1-visit) and two-visit (2- visit) endodontic retreatment after 18 months by cone-beam computed tomography (CBCT) and analyze clinical signs and symptoms; b) monitor and compare the microbial load and profile; levels of endotoxins and lipoteichoic acid in teeth with posttreatment apical periodontitis (PTAP); c) compare the postoperative pain between the groups by the visual analog pain scale (VAS); d) correlate the variables with themselves. Forty teeth with PTAP were selected and submitted to CBCT. The sampling procedure was performed: after filling material removal (S1), after biomechanical preparation (S2), and after the intracanal medication placement (S3). VAS was provided for assessment of the postoperative pain at different time-points (24 h, 48 h, and 7 days). Root canal contents were submitted to microbiological assessment by culture technique (CFU/mL) and Checkerboard DNA-DNA hybridization, and the determination of LPS (UE/mL) and LTA (pg/mL) levels by Limulus amebocyte lysate and enzyme-linked immunosorbent assays, respectively. Periapical lesions volumes were obtained by the ITK snap program. Data were statistically analyzed. CFU/mL, UE/mL, and LTA (pg/mL) decreased after biomechanical preparation, with their maintenance after the use of intracanal medication (p>0.05). All root canal samples had their baseline values (S1) higher than those found before the root canal obturation (residual values) for all parameters. Regarding the residual values, higher values of CFU/mL and lower values of LTA were found in 2-visit groups (p<0.05). The most frequently Gram-negative microorganisms found during sampling procedures were F. nucleatum, C. rectus, C. gingivalis, P. gingivalis, P. intermedia and L. buccalis, the Gram-positive ones were E. faecalis, E. faecium, S constellatus and S. mitis. There was no difference between the 1 or 2-visit treatments regarding postoperative symptoms (p>0.05). The initial volume of the periapical lesions ranged from 10 to 470 mm³, and the final ones ranged from 0 to 48 mm³. A significant reduction of the periapical lesion was observed after 18-months in both groups (p<0.0001), but no statistical difference was found between them (p>0.05). No significant differences were observed in the outcome of the two modalities of endodontic retreatment(AU)

Histological analysis of the association between formocresol and endotoxin in the subcutaneous tissue of mice

This study performed a histological analysis of the effect of formocresol associated to endotoxin (LPS) in the subcutaneous connective tissue of mice. Ninety mice were randomly assigned to 3 groups (n=30). Each animal received one plastic tube implant containing endotoxin solution (10 mg/mL), formocresol (original formula) or a mixture of endotoxin and formocresol. The endotoxin and formocresol groups served as controls. The periods of analysis were 7, 15 and 30 days. At each experimental period, tissue samples were collected and submitted to routine processing for histological analysis. Endotoxin and formocresol produced necrosis and chronic inflammation at 7 and 15 days. At 30 days, the endotoxin group showed no necrosis, while in the formocresol group necrosis persisted. The formocresol-endotoxin association produced necrosis and chronic inflammation in the same way as observed with formocresol at all experimental periods. In conclusion, formocresol seems not to be able to inactive the toxic effects of endotoxin in connective tissues.

O objetivo deste estudo foi avaliar histologicamente o efeito da associação do formocresol com endotoxina (LPS) em tecido conjuntivo de camundongos. Noventa camundongos foram divididos em três grupos de 30 camundongos cada. Cada camundongo recebeu um implante subcutâneo de tubo plástico contendo solução de endotoxina (10 mg/ml), formocresol (fórmula original), ou uma mistura de formocresol com endotoxina. Os grupos da endotoxina e formocresol foram considerados grupos controle. Os períodos de análise foram 7, 15 e 30 dias. Após os períodos experimentais, os tecidos foram removidos e submetidos a processamento histológico. Os resultados obtidos indicam que a endotoxina e o formocresol produzem necrose e inflamação tecidual crônica aos 7 e 15 dias e aos 30 dias o grupo da endotoxina não mostrava necrose e no grupo do formocresol a necrose persistiu. A combinação formocresol e endotoxina mostrou necrose e inflamação crônica com resultados semelhantes ao do grupo formocresol para todos os períodos experimentais. Pode-se concluir que o formocresol parece não ser capaz de inativar os efeitos tóxicos da endotoxina.

Development of Toxic Anterior Segment Syndrome Immediately after Uneventful Phaco Surgery

PURPOSE: We report on 15 cases of suspected toxic anterior segment syndrome after uneventful phaco surgery. METHODS: We retrospectively reviewed the charts of patients who had developed toxic anterior segment syndrome (TASS) after uneventful phacoemulsification for senile cataracts between April and December of 2005. Clinical features and all possible causes were investigated including irrigating solutions or drugs, surgical instruments or intraocular lenses, sterilization techniques for instruments, or any other accompanying disease. RESULTS: The patients consisted of 2 males and 13 females with an average age of 64.7+/-10.9 years. Five different surgeons had performed their phaco surgeries. No abnormal preoperative or operative findings were reported. Nevertheless, all 15 patients developed a moderate degree of corneal edema. Ordinary treatments were not helpful. We suspect that lack of sterilization resulted in the development of the syndrome, because after ethylene oxide gas sterilization was replaced with autoclaving, no such incidents have occurred. CONCLUSIONS: Toxic anterior segment syndrome requires special attention and thorough management, including sterilization of reused surgical instruments.

Patogénesis de la hipertensión portal / Pathogenesis of portal hypertension

It is now well established that portal hypertension is not a purely mechanical phenomenon. Primary hemodynamic alterations develop in the hepatic and systemic circulatory systems; these alterations in combination with mechanical factors contribute to the development of portal hypertension. In the hepatic circulation, these hemodynamic alterations are characterized by vasoconstriction and impaired hepatic vasodilatory responses, whereas in the systemic circulation, particularly in the splanchnic bed, vessels are hyperemic with increased flow. Thus, an increase in intrahepatic resistance in conjunction with increased portal venous inflow, mediated through splanchnic dilation, contributes to the development of portal hypertension. The ensuing development of elevated flow and transmural pressure through collateral vessels from the hypertensive portal vasculature into the lower pressure systemic venous circulation accounts for many of the complications, such as bleeding esophageal varices, observed with portal hypertension. The importance of the primary vascular origin of portal hypertension is emphasized by the utility of current therapies aimed at reversing these hemodynamic alterations, such as nitrates, which reduce portal pressure through direct intrahepatic vasodilatation, and fi blockers and octreotide, which reduce splanchnic vasodilatation and portal venous inflow. New evidence concerning relevant molecular mechanisms of contractile signaling pathways in hepatic stellate cells and the complex regulatory pathways of vasoactive molecules in liver endothelial cells makes a better understanding of these processes essential for developing further experimental therapies for portal hypertension. This article examines the current concepts relating to cellular mechanism that underlie the hemodynamic alterations that characterize and account for the development of portal hypertension.

Actualmente está bien establecido que la hipertensión portal no es un fenómeno puramente mecánico. En esta entidad se presentan alteraciones hemodinámicas primarias en los sistemas circulatorios hepático y sistémico; estas alteraciones en combinación con factores mecánicos, contribuyen al desarrollo de la hipertensión portal. En la circulación hepática, las alteraciones hemodinámicas se caracterizan por vasoconstricción y una respuesta anómala a la vasodilatación, mientras que en la circulación sistémica, especialmente en el lecho esplácnico, los vasos están congestivos y con un flujo aumentado. Por lo tanto un incremento en las resistencias intrahepáticas asociado a un aumento del flujo venoso portal, mediado a través de la dilatación esplácnica, contribuyen al desarrollo de la hipertensión portal. La consecuencia del flujo y la presión transmural elevada a través de los vasos colaterales a partir de una vasculatura portal hipertensa hacia la circulación venosa sistémica con menor presión, conlleva a muchas de las complicaciones observadas en la hipertensión portal, como la hemorragia por várices esofágicas. La importancia del origen vascular primario de la hipertensión portal se basa en la utilidad de terapias actuales orientadas a revertir estas alteraciones hemodinámicas, como los nitratos que reducen la presión portal, a través de vasodilatación intrahepática directa y los P bloqueadores y octreótida, que reducen la vasodilatación esplácnica y el flujo venoso portal. Además, existen nuevas evidencias en relación con los mecanismos moleculares de vías de señalización contráctil de las células estelares hepáticas y complejas vías de regulación de sustancias vasoactivas en las células endoteliales hepáticas que han ayudado a entender mejor estos procesos esenciales para el desarrollo de terapias experimentales para la hipertensión portal. Este artículo revisa los conceptos actuales relacionados con los mecanismos celulares causales de las alteraciones hemodinámicas que caracterizan y condicionan el desarrollo de la hipertensión portal.

Endotoxina, endotoxemia y sepsis / Endotoxins, endotoxemia and sepsis

La importancia creciente atribuida a la endotoxina y al factor de necrosis tumoral (TNF) como eje en la patogenia de la sepsis nos ha inducido a realizar un estudio clínico tendiente a demostrar la presencia de endotoxina en muestras de sangre obtenidas en el pre y posoperatorio en 30 enfermos hospitalizados en el Servicio de Cirugía del Hospital Clínico Regional de Concepción. Se demostró la presencia de endotoxina circulante en 17 de los 30 pacientes estudiados en el preoperatorio y esta cifra se elevó a 24 en las determinaciones realizadas en el posoperatorio. Si se compara los 30 enfermos en base al tipo de intervención quirúrgica se demuestra que el Test del Limulus fue positivo en 23 de los 25 enfermos sometidos a laparatomía por afecciones abdominales y sólo 1 de los 5 pacientes intervenidos por afecciones extraabdominales. Creemos importante destacar que los enfermos que presentaron sintomatología propia de la respuesta inflamatoria (fiebre, leucocitosis, hipermetabolismo, alteraciones hemodinámicas) evidenciaron con mayor frecuencia Test del Limulus positivo y que los dos únicos pacientes fallecidos presentaron, además de la sintomatología ya señalada, hipotensión arterial sistémica. Estos resultados revelan la interrelación entre endotoxemia, respuesta inflamatoria e hipotensión arterial sistémica, lo que debe considerarse como de mal pronóstico en los pacientes quirúrgicos graves

Disfunción hepática temprana secundaria a nutrición parenteral total en pacientes con sepsis de origen abdominal / Early disfunction secondary to total parenteral nutrition in patients with abdominal sepsis

Introducción. Es un hecho bien conocido que la nutrición parenteral total (NPT) se complica con disfunción hepática. Objetivo. Conocer la incidencia de la disfunción hepática temprana en pacientes con sepsis abdominal tratados con NPT. Pacientes y métodos. Se hizo un estudio prospectivo de seis meses en 57 pacientes (34 hombres, 23 mujeres, edad media 47.7 ñ 17.8 años) que ingresaron a una UCI de tercer nivel. Se les efectuaron pruebas de función hepática (PFH): TGO, TGP y bilirrubinas (BL) séricas al ingreso, y a la primera y segunda semana de estancia en la UCI. Resultados. Ocho pacientes (14 por ciento) tuvieron difunción hepática: se observó un incremento gradual y progresivo en la concentración sérica de la TGO (cuatro pacientes a la primera semana, dos a la segunda , p < 0.05), la TGP (seis pacientes en la primera semana, p < 0.05) y de la BL (siete casos a la primera semana p < 0.05). Conclusión. La NPT produce con frecuencia disfunción hepática temprana en los pacientes con sepsis abdominal

Papel del tubo digestivo en la generación del síndrome de falla múltiple de órganos / Role of the digestive system in the generation of the multiple organ failure syndrome

El síndrome de falla múltiple de órganos (SFMO) es un problema común en las UTIs. En su generación intervienen múltiples agentes tóxicos. El intestino parece ser una fuente importante de los mismos ya que es particularmente sensible a la isquemia y reperfusión. De hecho el acoplamiento DO2-VO2 se observa antes que en el resto del organismo. Esto lo convierte en un gatillo de lesión a distancia, permitiendo el paso de mediadores a la circulación general con reinicio sistémico del ciclo liberación-lesión

Sepsis: avances en fisiopatología y tratamiento 1993-1994

Sepsis is a term used to define a group of clinical manifestations caused by the response to the presence of microorganisms, of different types, in the blood stream. This paper reviews is a minute fashion recent knowledge regarding the role of endotoxin in the pathogenesis of the disease as well as that of cytokines as mediators of the process, and finally some of the new therapeutic approaches

Hipertermia experimental en conejos / Experimental hyperthermia in rabbit

En el presente trabajo se reprodujo y desarrolló un modelo experimental para producir hipertermia en conejos, mediante la administración de LPS de Escherichia coli (0,27:B8 de Sigma Chemical Co., EE.UU.). En la experiencia se utilizaron 15 conejos de 2.500ñ500g sanos, con temperaturas basales con un rango de 38,5 a 39,5§C. Los animales fueron agrupados en tres lotes. Los lotes 1 y 2, constituidos por 6 conejos cada uno y el lote 3 por 3 conejos. A cada animal del lote 1 se le administró vía endovenosa (EV) 0,1 *g/kg de peso de LPS de E. coli, en tanto que el lote 2 recibió 45 min previos al LPS por vía subcutánea (SC), plasma anti-LPS (600*g de inmunoglobulinas precipitantes de LPS/kg de peso corporal), con la finalidad de inhibir el efecto termogénico del LPS. El lote 3 actuó como control. Cada 15 min y durante 6h se registraron, vía rectal, las temperaturas en todos los animales. Los resultados obtenidos muestran que el LPS del serotipo (clase de bacteria) utilizado de E. coli en los lotes 1 y 2, produjo un cuadro de hipertermia durante 5h postadministración. Este presentó disposición bifásica con picos térmicos entre la primera y segunda hora y media postadministración. Los animales que recibieron, en forma previa, al LPS suero anti LPS, registraron temperaturas levemente inferiores (p<0,05). El lote testigo presentó temperatura normal

Efectos de la heparina en la microcirculación durante la sepsis en ratas / Heparine action over the microcirculation in septic rats

Se realizó un estudio comparativo entre dos grupos de ratas con peritonitis, con el objeto de relacionar la acción de la heparina en la difusión de la sepsis y sus acciones sobre la microcirculación. El modelo experimental fue ciego desvascularizado y perforado. Se realizaron cortes histológicos de riñón, pulmón, corazón, higado y suprarrenales, observándose en las ratas no heparinizadas peritonitis difusa y trombosis en la microcirculación con gérmenes. En el grupo de ratas heparinizadas se observaron abscesos bien delimitados en la cavidad con menor impacto funcional en los diferentes parénquimas. No se observó en este grupo fenómeno de coagulación intravascular diseminada

Absence of a demonstrable effect for endotoxin on the lysosomal enzyme activity of recruited macrophages in a rat model of liver injury

The endotoxin dose response of recruited and activated tissue macrophages isolated from a rat model of liver injury has been measured after 24 hours in in vitro culture, with respect to their production of a lysosomal enzyme, N-acetyl-glucosaminidase [NAG]. There were no significant differences in the NAG activity in cell lysates or supernatants following a two-hour exposure of the macrophages to a range of endotoxin concentrations [50 micro g. 5 ng/ml]; nor were any significant differences observed when compared to NAG activity of cells recruited but not exposed to endotoxin. The level of NAG activity in the supernatants and cell lysates of these recruited cells was significantly higher [p< 0.02] than the levels measured in resident macrophages [Kupffer cells] isolated from normal rat livers. We conclude that with respect to lysosomal enzyme release these cells have already been maximally activated in vivo and that further hepatic damage induced by endotoxin administration occurs through mechanisms other than increased release of lysosomal enzymes