In vivo and in vitro demonstration of nuclear bodies in vaccinia infected cells

Intranuclear inclusions in paramyxovirus-induced encephalitis: evidence for altered nuclear body differentiation

Intranuclear inclusion bodies (INB) are frequently encountered in viral infections, where they are thought to be accumulations of viral particles. However, for RNA viruses replicating in the cytoplasm, this compartmentalization represents a paradox not consistent with the viral replication cycle. To define the basis for intranuclear paramyxoviral inclusion bodies in astrocytes, natural cases of canine distemper virus subacute encephalitis were examined by light and transmission electron microscopy, and by quantitative confocal immunofluorescence microscopy. Although INB were viral antigen positive, they were not composed of structurally recognizable paramyxoviral nucleocapsids. The structural basis for the INB was instead viral antigen-associated forms of nucleolar development known as nuclear bodies. Three variants of the light microscopic Cowdry type A INB were complex nuclear bodies, giant beaded nuclear bodies (sphaeridia), and nuclear body-associated granulofilamentous matrices. In the latter, the granulofilamentous matrix frequently filled the nucleus, resulting in a fourth morphological INB variant, and was associated with morphological evidence of nuclear degeneration. These findings suggest a novel mechanism of virus-induced cytopathology whereby intranuclear viral protein exerts deleterious effects upon nucleolar differentiation in infected cells and hence altered host cell RNA metabolism.

Pathology of HIV-associated nephropathy: a detailed morphologic and comparative study

Clinical and pathologic findings in the kidneys of 30 consecutive acquired immunodeficiency syndrome (AIDS) autopsies and in 34 consecutive renal biopsies performed on HIV infected patients at our institution between 1983 and 1987 were studied. To determine if the lesions of HIV-associated nephropathy have morphologic specificity, a subgroup of 13 biopsies with a diagnosis of HIV-associated nephropathy (HIVN) were compared to 13 biopsies each of heroin-associated nephropathy (HAN) and of idiopathic focal segmental glomerulosclerosis (IFSGS) matched for patient age, proteinuria and serum creatinine. A diagnosis of HIVN was made in 1 of 30 (3.3%) AIDS autopsies and 26 of 34 (76.5%) renal biopsies. When compared to HAN and IFSGS, HIVN had more globally "collapsed" glomeruli (P less than 0.001), less glomerular hyalinosis (P less than 0.02), more severe visceral epithelial cell swelling (P less than 0.05), more numerous visceral epithelial cell droplets (P less than 0.002), more prevalent and severe tubular microcystic dilatation (P less than 0.02), and tubular cell degenerative changes (P less than 0.001). Focal glomerular electron-dense deposits were present in 14 of 26 cases. Tubuloreticular inclusions were extremely numerous in glomerular and interstitial capillary endothelial cells as well as in interstitial leukocytes (P less than 0.001). Granular degeneration of nuclear chromatin was present in 10 of 26 cases. Nuclear bodies were more numerous in tubular and interstitial cells of HIVN (P less than 0.01), particularly type 3 (P less than 0.001). Reversal of tissue T4/T8 ratio was observed. We conclude that while no single morphologic feature of HIVN is specific, the combination of clinical and pathologic findings is quite distinctive and permits a presumptive diagnosis of HIVN in otherwise asymptomatic carriers.

Immunoperoxidase staining of simple nuclear bodies in sclerosing panencephalitis (SSPE) by antiserum to Measles nucleocapsids

Nuclear bodies have been found with great consistency in brain tissue from patients with subacute sclerosing panencephalitis (SSPE). There has been controversy as to the significance of these structures and their relationship, if any, to the disease. In this study, a non-productive, cell-associated strain of SSPE measles virus grown in tissue culture on Vero cells showed the continued presence of nuclear bodies, frequently in close association with the continued presence of nuclear bodies, frequently in close association with the SSPE measles virus nucleocapsids. Immunoperoxidase (I-P) staining with specific antiserum against measles virus nucleocapsids was done. The resultant positive labeling of the nuclear bodies demonstrates that they contain measles virus antigen and suggests that the nuclear bodies play a role in the development of the measles virus nucleocapsids of SSPE.

Ultrastructural aspects of experimental swinepox with special reference to inclusion bodies

A light and electron microscopic study was performed on pox-like epidermal lesions in an experimentally infected pig. Light microscopical investigation of semithin sections revealed the presence of nuclear vacuoles and of different types of cytoplasmic inclusions. In electron microscopical studies large numbers of both immature and mature virus particles and the cytological changes indicative of pox virus infection were observed. Various types of intra-cytoplasmic inclusions -- i.e. fibrillar inclusions, crystalloid-containing dense inclusions, complex membraneous inclusions and dense homogeneous inclusions -- were encountered in addition to viroplasms and nuclear vacuoles. Because of the presence of vacuoles in nuclei of stratum spinosum cells the diagnosis swine pox by swinepox virus was most probable. These nuclear vacuoles have not been described in swine pox caused by vaccinia virus, the only other known cause of pox in swine.

Intranuclear inclusions in a case of Creutzfeldt-Jakob disease: an ultrastructural study

Two types of intranuclear inclusions were described in a brain biopsy from a patient with Creutzfeldt-Jakob disease. The first type of intranculear inclusion was papova virus-like and was observed within 20% of the nuclei of all astrocytes and neurons examined. The particles measured 32 nm in diameter and consisted of a dense core surrounded by a multi-layered shell. The second type of intranuclear inculsion was a granulo-fibrillar nuclear body found within the nuclei of astrocytes and neurons. The possible significance of these inculsions to the etiology of Creutzfeldt-Jakob disease is discussed.