Rabies: Interactions between neurons and viruses: A review of the history of Negri inclusion bodies

The first clear-cut description of a virus-nerve cell interaction was made by Adeichi Negri in 1903 with the detection of cytoplasmic bodies (Negri bodies) in subsets of neurons in the brain from rabies-infected animals. A biographical sketch of Negri is given here; he was born in Perugia, Italy, in 1875 and died in Pavia in 1912. In 1900 Negri became assistant to Camillo Golgi, who encouraged him to study rabies-infected brains with histological techniques. The report of intraneuronal bodies described by Negri as specific for rabies stimulated an intense debate both concerning their diagnostic value and their nature. The diagnostic value was finally determined in a study by Negri's wife, Lina Negri-Luzzani, in 1913, while the viral nature of the bodies had to await the introduction of electron microscopy and immunohistochemistry. However, the true significance of the Negri bodies is still mysterious, since they only develop in subsets of infected neurons and occur mainly after infection with wild. so-cal led 'street', virus strains and not after infection with strains passaged in the laboratory, so-called 'fixed' strains

Muscle involvement in leprosy: study of the anterior tibial muscle in 40 patients Alterações musculares na lepra: estudo do músculo tibial anterior em 40 pacientes

The involvement of skeletal striated muscle in leprosy is considered secondary due to peripheral neuropathy, but some studies point it to a primary muscle lesion. In order to investigate the muscle involvement in leprosy, we studied 40 patients (lepromatous 23, tuberculoid 13, borderline 2 and indeterminate 2). The motor nerve conduction of the peroneal nerves had a reduction of the velocity, decreased compound muscle action potential and sometimes absence of potentials. The electromyographic study of the anterior tibial muscle showed signs of recent and chronic denervation in 77.5% of the cases and no myopathic potentials. The anterior tibial muscle biopsy revealed denervation in 45% of the cases, interstitial inflammatory myopathy in 30% and mixed (myopathic and neuropathic) pattern in 12.5%. Acid fast bacillus was detected in 25% of the cases, always in the interstitial tissue. Inflammatory reaction was present in the interstitial space and in patients with the lepromatous type. The histological findings clearly defined the presence of the so-called "Leprous Interstitial Myositis" on the top of denervation signs.<br>O envolvimento do músculo estriado na lepra é considerado secundário à lesão dos nervos periféricos, mas alguns estudos relataram acometimento muscular primário. A fim de verificar esta controvérsia estudamos 40 pacientes com lepra, sendo 23 da forma lepromatosa, 13 da tuberculoide, 2 borderline e 2 indeterminada. Realizamos a neurocondução do nervo peroneiro, junto com eletromiografia e biópsia do músculo tibial anterior. Encontramos redução de velocidade de condução, da amplitude e algumas vezes ausência de potenciais no nervo peroneiro. A eletromiografia do tibial anterior mostrou sinais de desinervação recente e crônica em 77,5% dos casos e não foi encontrada evidência de padrão "miopático". A biópsia do músculo tibial anterior revelou desinervação em 45% dos casos, miopatia inflamatória intersticial em 30% e padrão misto (miopático e neuropático) em 12,5%. Bacilos alcool-ácido resistentes foram encontrados em 25% dos casos, sempre localizados no perimisio e endomisio. Na forma lepromatosa, a reação inflamatória estava presente no espaço intersticial. Os dados histológicos claramente definiram a presença de "Miosite Lepromatosa Intersticial" sobreposta às alterações histológicas encontradas em desinervação