Ubiquitin in motor neuron disease: study at the light and electron microscope.

Several neurodegenerative diseases, including motor neuron disease (MND), are characterized by formation of abnormal cytoskeleton-derived inclusions which contain ubiquitin (Ubq). We have studied the distribution of Ubq in 26 cases of MND with light and electron microscopic immunocytochemistry. Ubiquitin-positive inclusions were found in neurons of anterior horns in most cases of amyotrophic lateral sclerosis (ALS) but were not present in other forms of MND. Ubiquitin immunoreactivity was observed in 10-15 nm intraneuronal filaments, which were not stained by antibodies to neurofilaments, and on dense bodies of dystrophic neurites throughout the neuropil of anterior horns and pyramidal tracts. Data analysis showed a trend toward lower percentage of Ubq-positive neurons in cases with longer duration of illness or lower number of neurons. A high percentage of Ubq-positive inclusions occurred in cases with an aggressive clinical course, suggesting that ubiquitination takes place at early stages of the disease.     

Immunohistochemistry of glial reaction after injury in the rat: Double stainings and markers of cell proliferation

The astrocytic reaction in the rat after brain injury has been studied immunohistochemically for intermediate filaments (GFAP and vimentin), also with double staining procedures, and for markers of proliferation (BrdU and PCNA). GFAP-positive reactive astrocytes appeared around the lesion, where they were vimentin-positive and at a distance. BrdU and PCNA showed a high labelling index around the wound at day 2 and scattered positive nuclei were also found at a distance in the ipsilateral side. BrdU-positive astrocytes represented a minor fraction of GFAP- and vimentin-positive astrocytes. The expression of vimentin persisted at least 15 days after the lesion. Our results could suggest that distant reactive astrocytes originate through hypertrophy while those close to lesion arise by hyperplasia from mature or immature glial cells. The hypothesis is formulated that cells of the periventricular matrix contribute to the post-traumatic proliferative activity.     

The vascular response to tumor infiltration in malignant gliomas

Summary Neo-vascularization and endothelial hyperplasia have been shown to be very active in malignant gliomas. In this contribution the vascularization of the cortex infiltrated by malignant gliomas is morphometrically studied and the endothelial proliferations are immunohistochemically investigated and reconstructed by a three-dimensional computer-assisted procedure. Vessel density increases after tumor infiltration in some cases only. The diameter of vessels increases and so does the number of nuclei/vessel after the complete invasion of the cortex when vascular glomeruli develop. In completely infiltrated cortex with development of glomeruli and circumscribed necroses, vessel density is very low. No neoformation of vessels takes place before the complete infiltration of the cortex by the tumor. The hyperplastic formations, usually arranged parallel to the deep or outer cortical layers, take origin from the radially penetrating vessels from the meninges and their lateral branching. The hyperplasia deforms the vascular network, making it often inadequate to supply tumor cells. Immunohistochemically, the cells composing the hyperplastic structures are variably positive for factor VIII/RAg and, at a lesser extent, for -smooth muscle actin. The poorness of the vascular network in many instances of completely infiltrated cortex is responsible for the development of circumscribed necroses.Supported by Grant 87.01446.44 CNR, Rome and by A. I. R. C., Milan. Presented in part at the 63rd Annual Meeting of the American Association of Neuropathologists, Seattle, Washington, June 11–14, 1987     

Experimental brain tumors by transplacental ENU

Summary Experimental cerebral tumors have been induced by transplacental ENU. The morphologic study of the brains of treated rats revealed that cellular hyperplasias appear at the 30th day of extrauterine life in the paraventricular white matter, i.e., before the already known early neoplastic proliferations. Cytofluorimetric investigations failed to demonstrate differences between treated and control rats during the 1st month. On the contrary, adenylate cyclase activity is very high in that period. The duration of the latency period is discussed.This research was supported by Grants No. 79.00678.96 and No. 79.00664.96 of Progetto Finalizzato Control of Neoplastic Growth, Consiglio Nazionale delle Ricerche (C.N.R.), Rome     

Histochemistry and electron microscopy of muscle fibres in a case of congenital paramyotonia

Summary In a case of congenital paramyotonia a muscle biopsy was performed and studied morphologically, histochemically and ultrastructurally. A clearcut pattern of changes has been observed with ATPase and oxidative enzymes. On electron microscopy special changes known as tubular aggregates were found. The relationship between the two findings, as well as the significance of such alterations in the range of periodic paralyses and myotonic phenomena, are discussed.

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Zusammenfassung Bei einem Fall von kongenitaler Paramyotonie wurde eine Muskelbiopsie lichtmikroskopisch, histochemisch und elektronenoptisch untersucht. Typische Veränderungen ergaben sich in der ATPase-Färbung und in bezug auf oxydative Enzyme. Bei der elektronenoptischen Untersuchung wurden sogenannte tubuläre Aggregate festgestellt. Es wird die Beziehung der zwei Gruppen von Veränderungen zueinander diskutiert sowie auch die Bedeutung derselben im Rahmen der periodischen Lähmungen und der myotonen Phänomene.

     

Accuracy of direct examination and culture as compared to the anatomopathological examination for the diagnosis of chromoblastomycosis: a systematic review

BackgroundChromoblastomycosis is a skin infection caused by dematiaceous fungi that take the form of muriform cells in the tissue. It mainly manifests as verrucous plaques on the lower limbs of rural workers in tropical countries.ObjectivesThe primary objective of this review is to evaluate the accuracy of diagnostic methods for the identification of chromoblastomycosis, considering the histopathological examination as the reference test.MethodsMEDLINE, LILACS and Scielo databases were consulted using the terms “chromoblastomycosis” AND “diagnosis”. The eligibility criteria were: studies that evaluated the accuracy of tests for the diagnosis of chromoblastomycosis. Eleven studies were selected. Statistical analysis included the calculation of sensitivity and specificity of the diagnostic methods.ResultsConsidering the histopathological examination as the reference test, the culture showed a sensitivity (S) of 37.5% - 90.9% and a specificity (Sp) of 100%; while direct mycological examination showed S = 50% - 91.6% and Sp of 100% . Considering the culture as the reference test, the serology (precipitation techniques) showed S of 36% - 99%; and Sp of 80% - 100%; while the intradermal test showed S of 83.3% - 100% and Sp of 99.4% - 100%.Study limitationsThe small number of studies and very discrepant sensitivity results among them do not allow the calculation of summary measures through a meta-analysis.ConclusionsDirect mycological examination, culture, intradermal test and serology show sensitivity and specificity values ??for the diagnosis of chromoblastomycosis with no significant difference between the studies.     

Staging of osteonecrosis of the jaw requires computed tomography for accurate definition of the extent of bony disease

Management of osteonecrosis of the jaw associated with antiresorptive agents is challenging, and outcomes are unpredictable. The severity of disease is the main guide to management, and can help to predict prognosis. Most available staging systems for osteonecrosis, including the widely-used American Association of Oral and Maxillofacial Surgeons (AAOMS) system, classify severity on the basis of clinical and radiographic findings. However, clinical inspection and radiography are limited in their ability to identify the extent of necrotic bone disease compared with computed tomography (CT). We have organised a large multicentre retrospective study (known as MISSION) to investigate the agreement between the AAOMS staging system and the extent of osteonecrosis of the jaw (focal compared with diffuse involvement of bone) as detected on CT. We studied 799 patients with detailed clinical phenotyping who had CT images taken. Features of diffuse bone disease were identified on CT within all AAOMS stages (20%, 8%, 48%, and 24% of patients in stages 0, 1, 2, and 3, respectively). Of the patients classified as stage 0, 110/192 (57%) had diffuse disease on CT, and about 1 in 3 with CT evidence of diffuse bone disease was misclassified by the AAOMS system as having stages 0 and 1 osteonecrosis. In addition, more than a third of patients with AAOMS stage 2 (142/405, 35%) had focal bone disease on CT. We conclude that the AAOMS staging system does not correctly identify the extent of bony disease in patients with osteonecrosis of the jaw.