RESUMO
El absceso cerebral se constituye como un área central supurativa dentro del parénquima cerebral, dentro de una envoltura ampliamente vascularizada. Los patógenos ampliamente aislados en la patogénesis de esta entidad en niños son los Streptococos spp. A pesar del avance en la terapia antimicrobiana, las técnicas neuroquirúrgicas e imagenológicas, que permiten su diagnóstico y ubicación oportuna, el absceso cerebral aún se considera un problema de salud pública, con una importante incidencia, morbilidad y mortalidad en países en vía de desarrollo. Para el manejo de este tipo de infección del SNC, se requerirá de un abordaje multidisciplinario que involucre terapia médico quirúrgica. El objetivo de esta revisión es hacer un abordaje amplio sobre la patobiología del absceso cerebral relacionada con la labor concerniente al neurocirujano.
Brain abscess is formed as a central suppurativa area within the brain parenchyma, within an envelope extensively vascularized. Microorganisms largely isolated in the pathogenesis of this condition in children are Streptococos spp. Despite the progress in antimicrobial therapy, neurosurgical techniques and imagenologic support, which enabling timely diagnosis and location, brain abscess is still considered a public health problem and has an important incidence, morbidity and mortality in developing countries. To handle this type of CNS infection, will require a multidisciplinary approach involving surgical medical therapy. The aim of this review is to make a comprehensive approach on the pathobiology of brain abscess related to the work concerning the neurosurgeon.
Assuntos
Humanos , Lactente , Pré-Escolar , Abscesso Encefálico/complicações , Abscesso Encefálico/diagnóstico , Abscesso Encefálico/epidemiologia , Abscesso Encefálico/etiologia , Abscesso Encefálico , Abscesso Encefálico/terapia , Anti-Infecciosos/administração & dosagem , Sistema Nervoso/microbiologia , Diagnóstico por ImagemRESUMO
Human organism is interpenetrated by the world of microorganisms, from the conception until the death. This interpenetration involves different levels of interactions between the partners including trophic exchanges, bi-directional cell signaling and gene activation, besides genetic and epigenetic phenomena, and tends towards mutual adaptation and coevolution. Since these processes are critical for the survival of individuals and species, they rely on the existence of a complex organization of adaptive systems aiming at two apparently conflicting purposes: the maintenance of the internal coherence of each partner, and a mutually advantageous coexistence and progressive adaptation between them. Humans possess three adaptive systems: the nervous, the endocrine and the immune system, each internally organized into subsystems functionally connected by intraconnections, to maintain the internal coherence of the system. The three adaptive systems aim at the maintenance of the internal coherence of the organism and are functionally linked by interconnections, in such way that what happens to one is immediately sensed by the others. The different communities of infectious agents that live within the organism are also organized into functional networks. The members of each community are linked by intraconnections, represented by the mutual trophic, metabolic and other influences, while the different infectious communities affect each other through interconnections. Furthermore, by means of its adaptive systems, the organism influences and is influenced by the microbial communities through the existence of transconnections. It is proposed that these highly complex and dynamic networks, involving gene exchange and epigenetic phenomena, represent major coevolutionary forces for humans and microorganisms.
Assuntos
Evolução Biológica , Fenômenos Biológicos , Adaptação Fisiológica , Animais , DNA Bacteriano , Sistema Endócrino/microbiologia , Variação Genética , Interações Hospedeiro-Parasita , Humanos , Sistema Imunitário/microbiologia , Sistema Nervoso/microbiologiaRESUMO
Human organism is interpenetrated by the world of microorganisms, from the conception until the death. This interpenetration involves different levels of interactions between the partners including trophic exchanges, bi-directional cell signaling and gene activation, besides genetic and epigenetic phenomena, and tends towards mutual adaptation and coevolution. Since these processes are critical for the survival of individuals and species, they rely on the existence of a complex organization of adaptive systems aiming at two apparently conflicting purposes: the maintenance of the internal coherence of each partner, and a mutually advantageous coexistence and progressive adaptation between them. Humans possess three adaptive systems: the nervous, the endocrine and the immune system, each internally organized into subsystems functionally connected by intraconnections, to maintain the internal coherence of the system. The three adaptive systems aim at the maintenance of the internal coherence of the organism and are functionally linked by interconnections, in such way that what happens to one is immediately sensed by the others. The different communities of infectious agents that live within the organism are also organized into functional networks. The members of each community are linked by intraconnections, represented by the mutual trophic, metabolic and other influences, while the different infectious communities affect each other through interconnections. Furthermore, by means of its adaptive systems, the organism influences and is influenced by the microbial communities through the existence of transconnections. It is proposed that these highly complex and dynamic networks, involving gene exchange and epigenetic phenomena, represent major coevolutionary forces for humans and microorganisms
Assuntos
Humanos , Animais , Evolução Biológica , Fenômenos Biológicos , DNA Bacteriano , Sistema Endócrino/microbiologia , Variação Genética , Interações Hospedeiro-Parasita/genética , Sistema Imunitário/microbiologia , Sistema Nervoso/microbiologiaRESUMO
To determine the pathway adopted by peripherally inoculated Junin virus (JV) to reach the CNS, rat tissues were serially harvested to trace the sequence of viral progression from right hind footpad to brain. Immunoperoxidase (PAP) labeling of viral antigen, concomitantly with infectivity assays and histological examination of each selected sample, were carried out. As from the 2nd week post-infection (pi), neurological disease inducing 100% mortality at 1 month was evident. At day 5 pi, viral antigen was first detected at footpad level in epidermic and dermic cells, as well as in neighbouring myocytes; labeled macrophages infiltrating small nerve branches were also disclosed. As from 10-15 days pi, viral antigen became apparent along ipsilateral sciatic nerve structures and within lumbar spinal ganglion neurons, followed by a fast viral spread throughout CNS neurons that involved spinal cord and brain. Concurrent histopathology featured minimal inflammatory reaction together with generalized astrocytic activation. Hematogenous viral transport was negligible, since JV was isolated much earlier and in higher infectivity titers in neural tissues than in blood. It may be concluded that after viral replication in footpad, JV neural route was demonstrated by its PAP labeling from peripheral nerves to cerebral cortex.
Assuntos
Arenavirus do Novo Mundo/fisiologia , Febre Hemorrágica Americana/microbiologia , Sistema Nervoso/microbiologia , Animais , Antígenos Virais/metabolismo , Arenavirus do Novo Mundo/ultraestrutura , Encefalopatias/microbiologia , Encefalopatias/patologia , Febre Hemorrágica Americana/patologia , Técnicas Imunoenzimáticas , Ratos , Replicação ViralRESUMO
A distinguishing feature of Herpes simplex virus (HSV) infections is the ability of these viruses to persist for long periods in their host in nonreplicative or latent state. The study of pathogenesis of herpesvirus infections can be divided in: acute viral replication, establishment of latency, maintenance of latency and reactivation. In this paper we analyzed the viral genetic information which was identified as essential or very important for such events.