Feline poxvirus infection. A case report

Poxvirus infection of a domestic cat is reported. The clinical signs consisted of skin lesions only, which healed within two and a half months. Histopathology revealed cytoplasmatic inclusion bodies typical of pox virus infection. Virus particles morphologically related to the genus orthopoxvirus were detectable in the embedded skin tissue and in skin scraping by electron microscopy. No specific lesions were observed in the chick embryo chorioallantoic membrane inoculated with an extraction from skin scabs of the cat.

Regional distribution of lesions in the central nervous system of cats infected with feline immunodeficiency virus

Neuropathological examination of the central nervous system of 13 naturally and 13 experimentally feline immunodeficiency virus (FIV)-infected cats revealed diffuse gliosis of gray and white matter and vacuolar myelinopathy in a large proportion of infected animals, sometimes associated with lymphocytic meningitis. Multinucleated giant cell formation, the hallmark of multifocal giant cell encephalitis in HIV infection, was never observed. Morphometric analysis confirmed a marked increase of GFAP reactivity in infected cats. Gliosis was mainly present in cortical structures of frontal, parietal, and occipital lobes. Only one naturally infected animal evidenced clinical symptoms of neurological damage. This study confirms that FIV provides an interesting model for studying HIV-induced cortical and subcortical brain pathology believed to be the cause of the neurological manifestations frequently observed in AIDS patients.

Identification of beta-adrenoceptor subtypes in bovine ovarian and myometrial cell membranes

Beta-adrenoceptor (beta-AR) concentrations were measured in the ovary and in the myometrium of 36 adult Friesian cows using a radiometric assay. The beta-AR content in both tissues was determined using the highly specific antagonist (-) [3H]CGP 12177 and the amounts of beta-AR subtypes were discriminated in the presence of highly selective unlabelled ligands (CGP 20712A, ICI 118 551, CGP 25827A). Scatchard analysis revealed a good linearity and Kd values suggested the existence of high affinity beta-adrenergic sites in the bovine genital tract. Total beta-AR concentrations in the ovary and in the myometrium were, respectively, 87 +/- 7 (SEM) and 240 +/- 27 fmol mg-1 of membrane protein. beta 2-AR concentrations were significantly higher (P < 0.01) in the ovary (66 +/- 5) and the myometrium (180 +/- 29) than those of beta 1-AR (21 +/- 4 and 60 +/- 5, respectively). Significant differences (P < 0.05) were also to be found between high affinity state beta 2-AR and low affinity beta 2-AR concentrations, but their values correlated negatively in the two different tissues. Natural and synthetic agonists inhibited (-) [3H]CGP 12177 binding to beta-AR in the following order of potency: (-)isoproterenol > (+/-)clenbuterol > or = (-)adrenaline >> >> (-)noradrenaline, whereas synthetic antagonists inhibited binding in the following order of potency: (-)propranolol >> (+/-)ICI 118 551 >> >> (+/-)CGP 20712A.

Lectin histochemistry on squamous metaplasia in different epithelial tumors of dogs

Biotinylated lectins and avidin-biotin-peroxidase complex were used to study the correlation between cellular glycoconjugates' expression and squamous maturation in normal canine skin and in various epithelial neoplasms. Normal skin tissue was obtained from five, male, random-source dogs, 5 to 7 years old. The tumors tested, selected from the files of our Department, were fifteen squamous cell carcinomas from different tissue origin, five hepatoid perianal gland adenocarcinomas with squamous metaplasia, and fourteen solid mammary carcinomas with and without histologic evidence of squamous metaplasia. Except for mammary gland carcinomas, all tumors had been surgically excised from male dogs. Intermediate filament aggregation of twelve solid mammary gland carcinomas were studied electron microscopically. The basal and the lower spinous cells in normal skin and the less differentiated cells in squamous cell carcinomas stained moderately with Griffonia simplicifolia agglutinin-I. Spinous and granular cell layers stained strongly with Phytolacca americana mitogen and Arachis hypogaea agglutinin. Both lectins stained well-differentiated cells in squamous cell carcinomas. The electron microscopic study carried out in solid carcinomas of mammary glands revealed some relationship between the presence of intracytoplasmic tonofibrils and the binding of Griffonia simplicifolia agglutinin-I and Phytolacca americana mitogen to the tumors tested. Our results suggest that the glycosylation pattern occurring during normal keratinocyte differentiation is conserved in squamous cell carcinomas and that Griffonia simplicifolia agglutinin-I and Phytolacca americana mitogen may represent useful tools in distinguishing poorly differentiated squamous cell carcinomas from other poorly differentiated mammary epithelial tumors.

Lectin histochemical characteristics of the canine female mammary gland

Twelve biotinylated lectins and an avidin-biotin-peroxidase method were used to detect and localize specific carbohydrate residues on formalin-fixed, paraffin-embedded female canine mammary gland sections. Histologic sections from 3 lactating and 7 nonlactating mixed-breed dogs (age 5.6 +/- 0.35 years) were incubated with Arachis hypogea agglutinin (peanut agglutinin; PNA), Concanavalia ensiformis agglutinin (conA), Dolichos biflorus agglutinin (DBA), Glycine max agglutinin (SBA), Griffonia simplicifolia agglutinin-I (GS-I), Lens culinaris agglutinin (LCA), Lycopersicon esculentum agglutinin (LEA), Phytolacca americana mitogen (pokeweed mitogen; PWM), Ricinus communis agglutinin-I and -II (RCA-I and -II), Triticum vulgaris (WGA), and Ulex europaeus agglutinin-I (UEA-I). Each lectin had a specific binding pattern, except SBA and DBA. In nonlactating glands, PNA, conA, LEA, and UEA-I stained duct cells in a linear-binding pattern, with a mean percentage of positive ducts per section of 28.7 (+/- 0.6), 65.7 (+/- 0.3), 100 (+/- 0), and 8.4 (+/- 0.2), respectively. Strong apical, lateral, basal, and cytoplasmic positivity on duct cells was seen after incubation of the sections with RCA-I, RCA-II, and WGA in all ducts. In acinar cells, the binding pattern and the staining distribution of all the lectins studied were similar to those in duct cells. However, for PNA, conA, and UEA-I, the mean percentage of positive lobules per section was 33.7 (+/- 0.9), 62 (+/- 0.5), and 10.5 (+/- 0.2), respectively. In glands from lactating dogs, conA and UEA-I did not stain. The cytoplasm of all myoepithelial cells was moderately stained with RCA-I, RCA-II, and WGA.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental transmission of a sarcosporidian from Alpine ibex to domestic sheep and goats

Sporocysts of Sarcocystis sp. from dogs fed with ibex meat were orally inoculated into kids and lambs. Three kids, given 4 x 10(6) and 4 x 10(4) sporocysts, respectively, died from acute sarcocystosis. Schizonts, though found in all the tissues of these kids, were particularly numerous in the kidneys, brain and spinal cord. Another three kids inoculated with 5 x 10(3) sporocysts and two lambs, inoculated with 1 x 10(6) and 5 x 10(3) sporocysts, respectively, showed no clinical signs and were sacrificed between 111 and 130 days after infection. Mature sarcocysts were found both in the heart and striated muscles of these animals. No parasitic stage was found in two kids and two lambs used as uninoculated controls. Biological differences between Sarcocystis sp. from ibex and the other sarcosporidians with a canine-caprine or canine-ovine cycle are stressed.

Hepatitis B virus DNA (HBV-DNA) in anti-HBe positive sera

HBV-DNA measured by the spot hybridization technique, was found in the sera of 28 of 106 (26.4%) anti-HBe positive carriers of HBsAg. Dane particle-associated HBeAg, HBcAg and HBV-specific DNA-polymerase activity were found in the sera of nine (8.5%), five (4.7%) and two (1.9%) of these patients, respectively. All carriers with serum HBV-DNA had chronic liver disease and 18 had intrahepatic delta-Ag and serum anti-delta at titers higher than 1/5000. Intrahepatic HBcAg was detected in the nuclei of 90% of delta negative individuals; 50% of them also had cytoplasmic fluorescence. Only two of the 18 patients with intrahepatic delta-Ag (11%) had HBcAg in the liver. Viral nucleic acid was not found in the sera of 15 other patients with chronic hepatitis, seven of whom had intrahepatic delta-Ag. Serum HBV-DNA was also negative in the remaining 63 symptomless carriers of HBsAg lacking markers of delta infection. Interestingly, although DNA-polymerase negative, some sera gave autoradiographic spots of high optical density. HBV-DNA was detected in them at concentrations typical of sera which are usually both DNA-polymerase and HBeAg positive. Detection of HBV-DNA in serum represents the most direct and sensitive in vitro assay for assessing HBV infectivity and characterizes HBsAg carriers with HBV-related liver damage and ongoing HBV replication independently from the state of HBeAg/anti-HBe system. In the Mediterranean area, the majority of anti-HBe positive carriers with serum HBV-DNA have chronic liver disease and delta infection.

Experimental infection of chimpanzees with the HBsAg-associated delta (delta) agent: an ultrastructural study

Characteristic cytoplasmic membranous structures and intranuclear aggregates of particles similar to those reported in non-A, non-B hepatitis were observed by electron microscopy in the liver biopsies of chimpanzees inoculated with human serum, infectious for the delta agent. The ultrastructural changes were maximal during the intrahepatic production of the delta antigen, but were detected also independently of delta-Ag expression. The ultrastructural analogies provide further evidence that delta has properties distinct from HBV.

HBsAg/IgM complexes in serum of HBsAg carriers: partial characterization and clinical significance

HBsAg bound to IgM was detected in serum of HBsAg carriers with a radioimmunoassay based on selective absorption of the immunoglobulin on a solid phase coated with antiserum to human IgM. High titers of HBsAg/IgM were found in sera with the highest HBsAg binding capacity of polymerized human serum albumin (poly-HSA) and of C1q. These findings and the inhibition of HBsAg/IgM reaction by addition of purified poly-HSA suggest that the IgM component of the complex might bind to poly-HSA fixed on to HBsAg particles and possibly represent antibody to the modified plasma protein. HBsAg/IgM was detected in 95 (87%) patients with acute HBsAg positive hepatitis during the acute phase of infection and persisted after the fourth week only in patients who developed chronic liver disease. HBsAg/IgM were detected in one out of 15 carriers of the HBsAg with superimposed Non B hepatitis. HBsAg/IgM were also present in 76% to 100% of sera from chronic carriers without any relation to the extent of viral replication and to presence of severity of liver disease. Persistence of HBsAg/IgM in patients with acute hepatitis B may provide a useful tool to predict transition of HBV infection to chronicity.

Experimental HBV and delta infections of chimpanzees: occurrence and significance of intrahepatic immune complexes of HBcAg and delta antigen

The occurrence and pathogenetic role of intrahepatic deposits of immunoglobulins in experimental viral infection have been evaluated by determining with immunofluorescence their capacity to fix complement in vitro [in vitro complement fixation (VCF)]. Liver biopsies from chimpanzees chronically or acutely infected with hepatitis B virus or the hepatitis B surface antigen (HBsAg)-associated delta agent were used in the study. VCF was observed in each animal expressing hepatitis B core antigen (HBcAg) or delta antigen in the liver and concurrently circulating the homologous antibody in the blood. In acutely infected animals, VCF appeared at the same time that the homologous serum antibody appeared, and the intensity of VCF staining was proportional to the antibody titer in the serum. In animals expressing sequentially the HBcAg/antibody system and then delta antigen and antibody to delta, VCF was first observed in HBcAg-containing nuclei and then in nuclei expressing delta antigen. There was no relationship between VCF and intrahepatic expression of HBsAg or serologic expression of hepatitis B e antigen (HBeAg). A positive VCF reaction appears related to the formation of intrahepatic immune complexes between HBcAg or delta antigen and the homologous antibody. Although acute hepatitis developed in parallel with the occurrence of VCF in two animals, strong VCF fluorescence was also observed in each of the asymptomatic carriers of HBsAg, and, in one of them, preexisting VCF staining of HBcAg disappeared in parallel with development of acute hepatitis. In experimentally infected chimpanzees, the finding in liver biopsies of immune complexes detectable by VCF appears to be a common epiphenomenon without pathogenic significance.

Role of the T-cell system in glomerulonephritis induced in rats by human serum albumin (HSA). An immunological and morphological study

The primary role of the T-cell system in immune-complex glomerulonephritis induced by intravenous weekly injections of human serum albumin (HSA) in rats has been demonstrated. The development of histological, ultrastructural and immunological glomerular alterations which are clearly recognizable in intact animals was prevented by neonatal thymectomy. In vitro tests of cellular immunity (LIF and PHA responsiveness) revealed a close relationship between the involvement of functioning T-cell subpopulations (at least T-helper) and the development of the classic glomerulonephritic pattern. In other words HSA antigen recognition by T lymphocytes, their cooperation with B lymphocytes, and the activation of the latter with related antibody response represent the immunological sequence which leads to the formation of the soluble circulating immune-complexes responsible for the glomerular injury. Our findings suggest that the same immunological sequence can represent the pathogenetic basis for many forms of glomerulonephritis in which T-dependent antigen stimulation is demonstrable. Our data are also discussed in the light of results obtained by others in immuneglomerulonephritis induced in nude athymic mice.

delta Agent: association of delta antigen with hepatitis B surface antigen and RNA in serum of delta-infected chimpanzees

The hepatitis B virus-associated beta antigen was found in the serum of experimentally infected chimpanzee as an internal component of a discrete subpopulation of hepatitis B surface antigen (HBsAg) particles. The 35- to 37-nm particles banded in CsCl at 1.24-1.25 g/cm3 and sedimented with a mobility intermediate between that of the hepatitis B virion and that of the 22-nm form of HBsAg. The particles contained only indistinct internal structure by electron microscopy and were not unique to delta agent infection, similar particles without delta-antigen activity being observed in the preinfection serum of HBsAg carrier chimpanzees. A small RNA (Mr, 5 X 10(5)) was temporally associated with delta antigen in the serum of infected chimpanzees and copurified with the delta-antigen-associated particles. This RNA is smaller than the genomes of known RNA viruses but larger than the viroids of higher plants.

Transmission of the hepatitis B virus-associated delta antigen to chimpanzees

Inoculation of hepatitis B surface antigen (HBsAg)-positive sera from patients with chronic liver disease and intrahepatic delta (delta) into chimpanzees susceptible to infection with hepatitis B virus (HBV) resulted in type B hepatitis and delta markers (delta antigen and antibody to delta) in recipient animals. A dilution (10(-8)) of serum induced type B hepatitis without delta markers in another HBV-susceptible animal. HBV infection and delta markers did not develop in animals with preexisting titers of antibody of HBsAg. In chimpanzees with circulating HBsAg at the time of inoculation, synthesis of delta occurred earlier and its extent and duration were greater than in animals previously unexposed to HBV; coincident with synthesis of delta, hepatitis occurred in chronic HBsAg carriers, and synthesis of preexisting HBV gene products (HBsAg and hepatitis B core antigen) was diminished. Delta appears to be a marker of a transmissible pathogenic agent, either an HBV variant or another agent that requires the helper functions of HBV, that is defective and interferes with HBV replication.

An ultrastructural and immunohistochemical study on the delta antigen associated with the hepatitis B virus

Thirteen liver biopsies in which the delta antigen was detected by immunofluorescence were studied by electron microscopy and immune electron microscopy with peroxidase labelled IgG and F(ab1)2 fraction obtained from a human antiserum containing high-titre anti-delta antibodies. The findings were compared with those obtained in 11 HBcAg positive and in two HBsAg negative controls. Neither unique particulate morphology nor any HB virus ultrastructural component were visualised in the delta positive specimens; 20-23 nm naked core particles were observed in 10 of 11 biopsies displaying the HBcAg in immunofluorescence. Delta positive nuclei frequently contained dense round structures of diameter varying between 20 and 30 nm with a soft indistinct edge. These granules did not exhibit characteristic ultrastructural features which enabled them to be distinguished from other granular material observed occasionally in nuclei of normal and diseased livers. However, their association with the delta antigen has been proved by the deposition on identical structures of peroxidase labelled anti-delta antibody. These results suggest that the delta antigen is unrelated to the Dane particle, the putative HB virus. The granules observed in the delta positive nuclei are composed of an amorphous matrix, possibly insoluble aggregates of the delta antigen.

Immunofluorescence detection of new antigen-antibody system (delta/anti-delta) associated to hepatitis B virus in liver and in serum of HBsAg carriers

A new antigen-antibody system associated with the hepatitis B virus and immunologically distinct from the HB surface, core, and e systems is reported. The new antigen, termed delta, was detected by direct immunofluorescence only in the liver cell nuclei of patients with HBsAg positive chronic liver disease. At present, the intrahepatic expression of HBcAg and delta antigen appears to be mutually exclusive. No ultrastructural aspect corresponding to the delta antigen could be identified under the electron microscope. delta antibody was found in the serum of chronic HBsAg carriers, with a higher prevalence in patients with liver damage. The nuclear fluorescence patterns of HBcAg and delta antigen were similar; it is only possible to discriminate between the two antigens by using the respective specific antisera.

Immuno-electron-cytochemical localization of the somatostatin cells in the human antral mucosa

Immuno-cytochemical methods were used to identify, in light and electron microscopy, the somatostatin-containing cells of the human antral mucosa. By means of immunoperoxidase and immunofluorescence methods sequentially applied on the same section, it was shown that the somatostatin cells are distinct from the gastrin cell population; these two endocrine cell types are often closely related. On ultrathin sections from aldehyde-fixed. Epon-araldite embedded tissues, the site of storage of somatostatin was localized with the peroxidaseantiperoxidase complexes technique, after removal of the resin by means of sodium ethoxide. This procedure represents a new technical approach to the use of electron-cytochemical techniques. The results indicate that somatostatin, a growth hormone release inhibiting factor, is localized in the endocrine granules of the D cells.

Glomerular cell proliferation in human and experimental glomerulonephritis. Light- and electron-microscopical, and autoradiographic observations

Three mitoses of endothelial glomerular cells have been observed by electron microscopy in 3 different nephropathies (a mixed membranous and proliferative glomerulonephritis, an intracapillary glomerulonephritis, and a mixed IgG-IgM cryoglobulinemia). Further light- and electron-microscopical and autoradiographic investigations on the occurrence and nature of the dividing cells responsible for glomerular hypercellularity in glomerulonephritis have been carried out in rats with an immunocomplex-induced glomerulonephritis. A statistically significant difference between treated and control animals have been found in the number of mitoses and DNA-synthesizing nuclei. All dividing glomerular cells observed by electron microscopy were endothelial. It is therefore proved that in glomerulonephritis an actual glomerular cell proliferation does occur; proliferating cells are suggested to be endothelial in nature.

Complement fixing hepatitis B core antigen immune complexes in the liver of patients with HBs antigen positive chronic disease

One hundred and fifty-two biopsies from serologically HBsAg positive and negative patients with liver disease were studied in immunofluorescence: for the presence of the surface (HBs) and the core (HBc) antigenic determinants foeterminants of the hepatitis B virus, of immunoglobulins and complement (C) deposits, and for the capacity to fix human C. Circumstantial evidence is presented suggesting that HBc immune-complexes are a relevant feature in the establishment and progression of chronic HBSAg liver disease. C fixation by liver cells was shown in all HBC positive patients with chronic hepatitis; an active form was present in every case, except two with a persistent hepatitis, an inverse ratio of HBc to C binding fluorescence being noted between active chronic hepatitis and cirrhotic patients. HBc without C fixation was observed in only three patients in the incubation phase of infectious hepatitis. IgG deposits were often found in HBc containing, C fixing nuclei. No C binding or IgG deposits were observed in acute self-limited type B hepatitis, in serologically positive patients with normal liver or minimal histological lesions, with and without HBs cytoplasmic fluorescence in their biopsy, or in serologically negative individuals.

Human peripheral lung tumours: light and electron microscopic correlation

Thirteen human peripheral lung tumours have been studied in both light and electron microscopy. They were classified as epidermoid carcinoma, mucus-secreting cell adenocarcinoma, and alveolar cell adenocarcinoma, the latter made up of granular pneumocytes. Alveolar cell cancer, as defined by ultrastructural features, could assume different gross histological patterns in light microscopy, and therefore electron microscopy is required for its identification.Since neither squamous nor mucous metaplasia was observed in any alveolar cell tumour, it is tentatively suggested that all peripheral lung tumours which lack these features may be derived from granular pneumocytes, irrespective of whether they appear to be adenocarcinomata or large cell carcinomata when examined by light microscopy.