Description of Lyme disease-like syndrome in Brazil: is it a new tick borne disease or Lyme disease variation?

An emerging clinical entity that reproduces clinical manifestations similar to those observed in Lyme disease (LD) has been recently under discussion in Brazil. Due to etiological and laboratory particularities it is named LD-like syndrome or LD imitator syndrome. The condition is considered to be a zoonosis transmitted by ticks of the genus Amblyomma, possibly caused by interaction of multiple fastidious microorganisms originating a protean clinical picture, including neurological, osteoarticular and erythema migrans-like lesions. When peripheral blood of patients with LD-like syndrome is viewed under a dark-field microscope, mobile uncultivable spirochete-like bacteria are observed. PCR carried out with specific or conservative primers to recognize Borrelia burgdorferi sensu stricto or the genus Borrelia has been negative in ticks and in biological samples. Two different procedures, respectively involving hematoxylin and eosin staining of cerebrospinal fluid and electron microscopy analysis of blood, have revealed spirochetes not belonging to the genera Borrelia, Leptospira or Treponema. Surprisingly, co-infection with microorganisms resembling Mycoplasma and Chlamydia was observed on one occasion by electron microscopy analysis. We discuss here the possible existence of a new tick-borne disease in Brazil imitating LD, except for a higher frequency of recurrence episodes observed along prolonged clinical follow-up.

Detection of Mycoplasma pneumoniae and Chlamydia pneumoniae in ruptured atherosclerotic plaques

This paper reports what is apparently the first observation of Mycoplasma pneumoniae in association with Chlamydia pneumoniae in thrombosed ruptured atheromas. We performed electron microscopy and in situ hybridization in specimens from three patients who died of acute myocardial infarction. These patients had typical symptoms of acute ischemic syndrome. Mycoplasmas were present mainly in the lipid core of the ruptured thrombosed plaque. Vulnerable atheromas are rich in cholesterol and may favor the growth of mycoplasmas, the only microorganisms that require cholesterol for survival. We suggest that the association of Mycoplasma pneumoniae and Chlamydia pneumoniae may increase the virulence of these microorganisms, favoring proliferation, plaque inflammation and possibly plaque rupture

Biópsia endomiocárdica e avaliaçäo anatomopatalógica / Endomyocardial biopsy and heart transplantation

A biópsia endomiocárdica é o principal meio para estabelecermos, de forma fidedigna, o diagnóstico de rejeiçäo aguda, que pode ser dos tipos humoral, celular ou misto. A rejeiçäo aguda humoral é rara, mediada por anticorpos e caracteriza-se por lesöes da microcirculaçào miocárdica, sen infiltrado inflamatório. Por causa do lado, a rejeiçäo aguda celular é caracterizada pela infiltraçäo do miocárdio por células linfocitárias. Se existe agressäo dos miócitos pelo infiltrado inflamatório, a rejeiçäo éraduada como moderada ou severa e necessita de tratamento. O acompanhamento evolutivo dos episódios de rejeiçäo é fundamental. Processos infecciosos que acometem o miocárdio, particularmente a toxoplasmose e a recidiva da doença de Chagas, podem ser diagnosticados pela biópisa endomiocárdica. Técnicas imuno-histoquímicas säo de grande valia para o estabelecimento desses diagnósticos. Alteraçöes secundárias a isquemia perioperatória, caracterizadas por microinfartos, podem estar presentes nas primeiras bóisas e näo devem ser confundidas com rejeiçäo aguda.

Thin-section and freeze-fracture study of post-mortem chenges in dog myocardium

Fragments of dog hearts submitted to 1,6,10,24 and 48 h of autolysis at 20-C were studied with freeze-fracture and thin-section techniques under the transmission electron microscope. The freeze-fracture replicas revealed maximal reduction in the mean number and clustering of intramembrane particles at 6 h post mortem, indicating irreversible cellular damage. However, sings of lethal damage (intramitochondrial amorphous dense bodies) were not observed in thin sections of the same material. The present study indicates that signs of irreversible damage similar to that occuring in in vivo ischemic alterations can be detected earlier by the freeze-fracture technique than by the thin-section technique