Recovery of a new herpesvirus from the ground squirrel (Citellus citellus).

A new herpesvirus recovered from the kidneys of mature ground squirrels (Citellus citellus) produced an effect in tissue culture cells resembling that of herpesviruses, including the formation of multinucleated syncytia and type A intranuclear inclusions. The isolate caused latent infection in the natural host, but it proved fatal for intracerebrally inoculated suckling mice and it produced pocks on the chorioallantoic membrane of embryonated eggs. Electron-microscopic examination of infected cells revealed intranuclear virus particles exhibiting a size and ultrastructure characteristic of herpesviruses. The isolate was ether-resistant and a DNA nucleic acid type was inferred from observations on inhibition by fluorinated pyrimidine. This ground squirrel herpesvirus was found to be antigenically distinct from Herpesvirus hominis and from ground squirrel cytomegalovirus, with no detectable cross-reactivity.     

Herpesvirus simiae infection in Macaca radiata

Forty of 79 bonnet macaques (Macaca radiata) housed in an outdoor structure became infected with a respiratory disease, and 16 died. The most conspicuous lesions were those of hemorrhagic interstitial lobar pneumonia and focal hepatic necrosis with monocytic infiltration and eosinophilic intranuclear inclusions. A virus, in high titer, was obtained from the lung and liver of two fatal cases (10⁷ TCID₅₀ × gram of tissue) by inoculating tissue homogenates in primary vervet monkey kidney, BSC-1, and MA104 cell cultures. The cytopathic effect was identical with that induced by Herpesvirus simiae in the same cell cultures. Similar cellular changes were seen in LLC-MK2 cell cultures. Infected cells contained eosinophilic intranuclear inclusions, and intranuclear herpes-like virus particles were seen by electron microscopy. The virus could not be passed serially in mice by the intracerebral route of inoculation. Bonnet monkeys (herpes antibody-free), inoculated intravenously with the virus, developed vesicular lesions on the arms, face, hands, and soles of the feet; and the virus was recovered from the vesicular fluid. All lesions disappeared within three weeks after inoculation, and the animals later recovered. On the basis of host range, cytopathic effect, electron microscopy, mouse susceptibility, and the results of neutralization tests in tissue cultures, the virus was identified as Herpesvirus simiae.     

Potential of Kidney Cell Cultures from Nonhibernating Thirteen-Lined Ground Squirrels (Citellus tridecemlineatus) for Virus Propagation

Kidney cells were cultured in vitro from nonhibernating thirteen-lined ground squirrels (Citellus tridecemlineatus). These primary ground squirrel kidney cultures were tested for the ability to support the replication of 13 viruses representing nine virus groups. The cultures were shown to be susceptible to every virus tested, either by an increase in infectious virus or by the cytopathic effect produced.     

Hepatitis in skunks caused by the virus of infectious canine hepatitis.

Two cases of acute, fatal, hepatitis occurred in young, striped skunks (Mephitis mephitis) trapped in southern Ontario. Histologically, lesions in the liver were similar to infectious canine hepatitis. A virus was isolated which produced large intranuclear inclusions in dog kidney cell cultures. These inclusions were Feulgen-positive and fluoresced green with acridine orange stain. The skunk hepatitis isolate was identified as the virus of infectious canine hepatitis by virus neutralization tests.     

Papovaviral sialoadenitis in athymic nude rats

A wasting disease was found in 32 athymic nude rats. The rats had parotid sialoadenitis with intranuclear inclusion bodies in ductal and acinar epithelial cells. Other common lesions included bronchitis, bronchiolitis and secondary bacterial pneumonia. Less commonly, rhinitis and Harderian adenitis were seen. Intranuclear inclusions were also seen in bronchial epithelium of 1 rat, Harderian gland acini of 1 rat and laryngeal glands of 2 rats. Viral particles, averaging 45 nm in diameter, sometimes in crystalline arrays, were found in the nucleus of parotid epithelial cells. By the use of the avidin-biotin-peroxidase complex (ABC) immunoperoxidase technique, antibodies to disrupted SV40 virus (the group specific antigen of the polyomavirus (miopapovavirus) genus of the papovavirus family) reacted with intranuclear inclusions and cytoplasm of parotid epithelium and inclusions in lung and Harderian gland. The viral antigen did not cross react with antibodies to mouse polyoma, mouse K or disrupted bovine papilloma viruses.     

Susceptibility of Mammalian (Hamster) Cell Culture to Infection with Herpesvirus of Turkeys

Herpesvirus of turkeys (HVT) infected and replicated in hamster kidney cells as evidenced by cytopathic effects, intranuclear inclusions, and by the presence of herpesvirus particles as seen by electron microscopy. Additional evidence for the presence of HVT in cell cultures was determined by the serum neutralization, complement fixation, and the fluorescent-antibody tests.     

Systemic arteriopathy in SIV-infected rhesus macaques (Macaca mulatta)

BACKGROUND: Severe disseminated vasculopathy was observed in two simian immunodeficiency virus (SIV)-infected rhesus macaques (Macaca mulatta). These animals developed clinical signs of AIDS, including lymphadenopathy, weight loss, diarrhea and collapse. RESULTS AND DISCUSSION: Grossly, both animals showed emaciation, lymphadenopathy, vegetations on the mitral valve, renal infarcts and a dilated intestine; one animal had multifocal hemorrhages in multiple organs. Histologically, both cases had disseminated arteriopathy characterized by intimal thickening and fibrosis with varying degrees of vasculitis. The lesion was prominent in the kidney, intestine, pancreas, liver, heart, lymph nodes, spleen and testis. Occasional venules had intimal thickening. Both cases had cytomegalovirus (CMV) infection with intranuclear inclusions, CMV antigen and nucleic acid; some inclusions were observed in endothelial cells within some of the vascular lesions in one of the two. These data suggest that CMV caused the unusual lesions.     

A parvo-like virus disease of penaeid shrimp

Cultured populations of four penaeid shrimp species (Crustacea, Decapoda) from four separate culture facilities in Asia were found to be adversely affected by a disease of presumed viral etiology. Individual shrimp with the disease displayed nonspecific signs, including poor growth rate, anorexia, reduced preening activity, increased surface fouling, and occasional opacity of tail musculature. These signs were accompanied by mortalities during the juvenile stages, after apparently normal development through the larval and postlarval stages. Accumulative mortality rates in epizootics in Penaeus merguiensis and P. semisulcatus reached as high as 50 to 100%, respectively, of the affected populations within 4 to 8 weeks of disease onset. The principal lesion, common to all four species, was necrosis and atrophy of the hepatopancreas, accompanied by the presence of large prominent basophilic, PAS-negative, Fuelgen-positive intranuclear inclusion bodies in affected hepatopancreatic tubule epithelial cells (hepatopancreatocytes). These inclusion bodies presumably developed from small, eosinophilic, intranuclear bodies that were also present in the affected tissues. Electron microscopy of affected hepatopancreatocytes revealed aggregations of 22- to 24-nm-diameter virus particles within the electron-dense granular inclusion body ground substance. The virus particle size and morphology, the close association of the nucleolus with the developing inclusion body, and the presence of intranuclear bodies within developing inclusion bodies are similar to cytopathological features reported for parvovirus infections in insects and vertebrates. It is suggested that this presumed virus disease of cultured penaeid shrimp be called HPV for Hepatopancreatic Parvo-like Virus disease.     

Karyomegaly and intranuclear inclusions in the renal tubules of sentinel ICR mice (mus musculus)

Among 585 sentinel ICR mice (Mus musculus), 8 (7 female, 1 male) had unusual microscopic lesions in the kidney. Light microscopy revealed occasional tubular epithelial cells with large, karyomegalic nuclei that contained intranuclear inclusions and marginated chromatin. These cells were randomly present in the cortex and medulla but were more prominent near the corticomedullary junc tion. Rare pyknotic cells and mild interstitial infiltrates of lymphocytes and plasma cells were associated with occasional foci of abnormal cells. Electron microscopy performed on 2 (1 female, 1 male) of the mice demonstrated intranuclear inclusions composed of abundant flocculent, electron-lucent material. No viral particles or other pathogens were identified. General health monitoring that included serology, microbiology, parasitology, necropsy, and histopathology was negative for pathogens. Polymerase chain reaction-based testing for polyomavirus and immunohistochemistry for adenovirus were performed on 5 of the 7 female mice; all were negative for both viruses. In light of microscopy findings and the lack of evidence for an infectious agent, the tubular lesions were considered degenerative changes, possibly due to a toxic insult. The cause and significance of the findings in these mice can not be explained fully.     

Microscopic evidence of adenoviral infection in a muskrat in Illinois

A wild muskrat (Ondatra zibethicus) found moribund in Illinois (USA) had minimal meningitis and pleuritis, probably of bacterial origin. There were large, basophilic, intranuclear inclusion bodies within scattered enterocytes. The inclusions were microscopically typical of those produced by adenoviruses, and ultrastructurally were intranuclear paracrystalline arrays of virus particles with characteristics of adenoviruses. The significance of the adenovirus infection in this muskrat is unknown.     

Viral basophilic inclusions in the digestive gland of razor clams Ensis arcuatus (Pharidae) in Galicia (NW Spain)

During a histological survey of razor clam Ensis arcuatus (Jeffreys, 1865) from Galicia (NW Spain), basophilic inclusion bodies were observed in epithelial cells of the digestive gland. Transmission electron microscopy revealed the intranuclear position of these inclusions containing viral particles with icosahedral symmetry. Size and symmetry of these unenveloped virus particles suggest similarities to the families Papillomaviridae and Polyomaviridae which have been described as causing a viral gametocytic hypertrophy in oysters Crassostrea virginica and C. gigas. This is the first report of viral particles in E. arcuatus.     

Studies with bovine parainfluenza - 3 virus in u.a.R. (Egypt)

A bovine strain of myxovirus parainfluenza-3 (MP3) virus, designated S virus, was isolated from lung tissue collected from cattle with respiratory illness in 1963. The virus agglutinates mammalian and avian erythrocytes, and is sensitive to ether, sodium desoxycholate and trypsin. It grows in primary calf kidney, buffalo kidney, dog kidney, camel kidney and MS cell cultures. The S virus forms well-defined plaques in buffalo and calf kidney cells on the 5th or 6th day after inoculation. Examination of cell cultures following inoculation with S virus revealed giant cell formation, and introcytoplasmic and intranuclear inclusions. At 37 degrees C the virus titer dropped from 10(10.4) to 10(2.6) in 3 days. Virus was completely inactivated at 56 degrees C within 15 minutes. Growth-curve studies in tissue culture monolayer cells revealed a latent period of 10 hours. The intracellular virus titer was slightly lower than that of extracellular virus. The isolate was identified as MP3 virus by serum neutralization and hemagglutination-inhibition tests. Antibodies (HI) to S virus were shown to be present in a significant proportion of Egyptian cattle. The epidemiological significance of MP3 (bovine strain) virus in U.A.R. is discussed.     

ELECTRON MICROSCOPE OBSERVATIONS ON INTRACELLULAR VIRUS-LIKE PARTICLES ASSOCIATED WITH THE CELLS OF THE LUCKÉ RENAL ADENOCARCINOMA

The common renal adenocarcinoma of the leopard frog was studied in thin sections with the electron microscope. Approximately a third of the tumors examined were found to contain spheroidal bodies of uniform size and distinctive morphology that are believed to be virus particles. These consist of hollow spheres (90 to 100 mµ) having a thick capsule and a dense inner body (35 to 40 mµ) that is eccentrically placed within the central cavity (70 to 80 mµ). Virus particles of this kind occur principally in the cytoplasm but occasionally they are also found in the nucleus and in the extracellular spaces of the tumor. The intranuclear inclusion bodies that are visible with the light microscope are largely comprised of hollow, spherical vesicles with thin limiting membranes. These are embedded in a finely granular matrix. A few of the thin walled vesicles contain a dense inner body like that of the cytoplasmic virus particles. This suggests that they may be immature virus particles. The inclusion bodies are believed to be formed in the course of virus multiplication but they usually contain very few mature virus particles. Bundles of dense filaments and peculiar vacuolar inclusions also occur in the cytoplasm of the tumor cells. These seem to be related in some way to the presence of virus but their origin and significance remain obscure. These findings are discussed in relation to previous work suggesting that the Lucké adenocarcinoma is caused by an organ-specific filtrable agent. It is concluded that the "virus particles" found in electron micrographs of the tumor cells may be the postulated tumor agent. On the other hand, the possibility remains that the particles described here are not those that are causally related to the tumors.     

Electron microscope observations on intracellular virus-like particles associated with the cells of the Lucké renal adenocarcinoma

The common renal adenocarcinoma of the leopard frog was studied in thin sections with the electron microscope. Approximately a third of the tumors examined were found to contain spheroidal bodies of uniform size and distinctive morphology that are believed to be virus particles. These consist of hollow spheres (90 to 100 mmicro) having a thick capsule and a dense inner body (35 to 40 mmicro) that is eccentrically placed within the central cavity (70 to 80 mmicro). Virus particles of this kind occur principally in the cytoplasm but occasionally they are also found in the nucleus and in the extracellular spaces of the tumor. The intranuclear inclusion bodies that are visible with the light microscope are largely comprised of hollow, spherical vesicles with thin limiting membranes. These are embedded in a finely granular matrix. A few of the thin walled vesicles contain a dense inner body like that of the cytoplasmic virus particles. This suggests that they may be immature virus particles. The inclusion bodies are believed to be formed in the course of virus multiplication but they usually contain very few mature virus particles. Bundles of dense filaments and peculiar vacuolar inclusions also occur in the cytoplasm of the tumor cells. These seem to be related in some way to the presence of virus but their origin and significance remain obscure. These findings are discussed in relation to previous work suggesting that the Lucké adenocarcinoma is caused by an organ-specific filtrable agent. It is concluded that the "virus particles" found in electron micrographs of the tumor cells may be the postulated tumor agent. On the other hand, the possibility remains that the particles described here are not those that are causally related to the tumors.     

Electron Microscopic Localization of Herpesvirus-type Particles in Marek''s Disease

Upon cultivation of chicken lymphoid tumors induced by Georgia isolate of Marek's disease, clusters of refractile rounded cells appeared consistently in the cell cultures. Intranuclear mature, immature, enveloped, and empty herpesvirus-type particles, usually associated with smaller particles, were observed in all rounded cells in the affected areas. Cytoplasmic inclusions containing mature enveloped virus particles were also seen in the rounded cells. Often fibroblasts growing in the vicinity of the cytopathic effect area contained a few herpesvirus-type particles. The original tumors prior to cultivation did not reveal any virus particles, and the virus in infected cultures was always cell-associated. Control cell cultures neither developed the rounded cells nor demonstrated the presence of any type of virus particles.     

Fine structure and distribution of three types of virus-like particles in the sheep blowfly,Lucilia cuprina and associated cytopathic effects

The ultrastructure is described for three types of virus-like particles (VLP 1–3) found in thin sections of the sheep blowfly Lucilia cuprina and, in the case of one type (VLP 1), in negatively stained preparations. VLP 1 appears to be morphologically similar to the particles of chronic bee paralysis virus and RS virus of Drosophila and causes a highly characteristic vesiculation of mitochondria. VLP 2 has two forms, spherical and filamentous; these are seen mainly in the gut where the filaments proliferate in the apical parts of the cells and resemble reovirus-like particles found in the gut of Musca domestica. The third type of particle (VLP 3) is intranuclear and seen only rarely. It is arrayed in quasi-crystalline inclusions which resemble inclusions reported in cells and tissues of Drosophila.     

Ultrastructural organization of cardiomyocyte sarcolemma in hibernating animals

It was shown by electron microscopy that a highly convoluted sarcolemma, its numerous invaginations, well developed T-system contacting mainly with myofibrillar mitochondria and Z-zones were characteristic of cardiomyocytes of hibernants. In these cells lipid inclusions amounted as much as 3-4% of the cytoplasm. Cardiomyocytes of the arousing ground squirrels often revealed a complex of structures in the perinuclear area, responsible for protein synthesis and vesicle formation. Along with it the number of vesicles, including delineated ones, the majority of whom are contacting the sarcolemma, were manifested in the cell near-membrane area. A possible mechanism of cardiomyocyte plasma membrane rearrangements in ground squirrels and of alteration of their properties at the arousal, through a gradual replacement of plasma membrane material for the cytoplasmic vesicle bilayer, is discussed.     

Comparison of Subacute Sclerosing Panencephalitis and Measles Viruses: an Electron Microscope Study

The ultrastructure of CV-1 cells infected with subacute sclerosing panencephalitis (SSPE) viruses was compared with that of CV-1 cells infected with the wild or Edmonston strain of measles virus. Both SSPE viruses and the measles viruses produced two types of nucleocapsid structures: smooth filaments, 15 to 17 nm in diameter, and granular filaments, 22 to 25 nm. The smooth and granular filaments produced by SSPE and measles virus did not differ in appearance. In CV-1 cells infected with SSPE viruses, smooth filaments formed large intranuclear inclusions and granular filaments occupied a large area of the cytoplasm, but always spared the area under the cell membrane. Particles budding from the surface of these cells contained no nucleocapsids. In CV-1 cells infected with measles virus, only small aggregates of smooth filaments were seen in the nuclei. Granular filaments in the cytoplasm predominantly occupied the area under the cell membrane, and were aligned beneath the cell membrane in a parallel fashion and assembled into budding particles. These differences between SSPE and measles virus may be regarded as quantitative, but they do distinguish SSPE viruses from measles virus. Moreover, the formation of large nuclear inclusions filled with smooth filaments appears to be a characteristic process of SSPE, but not of measles, since this type of inclusion is invariably seen in SSPE brain tissues, brain cultures derived from them, and CV-1 cells infected with SSPE viruses.     

Intracellular localization of beryllium by analytical ion microscopy

After injection in the rat of a soluble beryllium salt, the distribution of this element was studied at the subcellular level by analytical ion microscopy. Beryllium is concentrated inside the nuclei with a particular affinity for the nuclei of the proximal tubule cells of the kidney. The same tissue was studied by electron microscopy and abnormal intranuclear inclusions were observed in the same variety of cells.