Syncytial Giant Cells Research Articles

Characteristics of Parker's rat coronavirus (PRC) replicated in L-2 cells

SummaryParker's rat coronavirus (PRC) is a naturally-occurring viral infection of the laboratory rat. On the first passage, ATCC strain 8190 of PRC replicated in L-2 cells. Using the tenth passage of PRC in L-2 cells, the characteristics of the virus were compared with previous studies of sialodacryoadenitis virus (SDAV) replicated in L-2 cells. Based on light and immunofluorescence microscopic examination of control and inoculated cell cultures, PRC-associated CPE was frequently confined primarily to individual cells, and there were relatively few syncytial giant cells. Maximum titers were recovered at 36h post inoculation (pi). Infectious virus was demonstrated at pH values ranging from 6.0 to 9.0 and a pH of 7.5 was determined to produce the highest titers of PRC. The optimum temperature for viral replication was 33°C. Up to 15 passages of PRC in L-929 cells failed to produce detectable virus. However, after adaptation in L-2 cells (20th passage), PRC replicated to high titers in L-929 cells. Previously, in vitro studies of rat coronaviruses have been hampered by the lack of an identified continuous cell line to replicate these viruses in the laboratory. L-2 cells represent a readily-available continuous cell line that can support the replication of relatively high titers of PRC.

Characterization of cell fusion in XC cells induced bySuncus murinus mammary tumor virus

Syncytium formation in a rat tumor cell line (XC) induced by Suncus murinus mammary tumor virus (Sm-MTV) was studied. Multinucleate giant cells containing 20-30 nuclei were formed in a monolayer of XC cells by cocultivation with X-ray-irradiated Sm-MTV producing cells (Sm-MT-1). By fluorescent antibody staining. Sm-MTV antigens were demonstrated in the cytoplasm of syncytia, and budding particles and intracytoplasmic A particles were found in syncytial giant cells by electron microscopy. Cell-free supernatant of Sm-MT-1 was capable of inducing syncytia at a much lower incidence than cocultivation of Sm-MT-1 cells. Syncytium formation was completely inhibited when anti-Sm-MTV bovine serum was added to the coculture medium. Pretreatment of XC cells with actinomycin-D caused a partial reduction of Sm-MTV-induced cell fusion, but syncytium formation did occur at a reduced rate even when cellular RNA synthesis was completely inhibited. Dexamethasone increased virus production in Sm-MT-1 cells, resulting in the enhancement of Sm-MTV mediated syncytium formation. Sm-MTV was found to have a unique characteristic of cell fusion activity on XC cells with striking enhancement by dexamethasone.

Replicating Marek's disease virus (MDV) serotype 2 DNA with inserted MDV serotype 1 DNA sequences in a Marek's disease lymphoblastoid cell line MSB1-41C

We characterized the properties of herpes-type viruses which grew well in a Marek's disease lymphoblastoid cell line, MSB1-41C, inducing cytopathic effect characterized by the formation of syncytial giant cells. Examination of the infectious virus by field inversion gel electrophoresis revealed the presence of DNA of about 180 kbp in both the culture fluid and cell fractions of the infected MSB-41C cells. The DNA was found to consist of Marek's disease virus (MDV) serotype 2 (MDV2) and MDV serotype 1 (MDV1) DNA by Southern blot hybridization. The MDV1 DNA consisted of sequences mainly from the long inverted repeats including multiple copies of 132 bp direct tandem repeats. Molecular cloning of BamHI digests of the MDV2 DNA revealed a fragment of MDV1 DNA and MDV2 DNA fused together, indicating that the recombinant MDV2 DNA had been generated by genetic recombination with the latent MDV1 DNA.

Electron microscopy of simian immunodeficiency virus isolated from a sooty mangabey (Cercocebus Atys) in Liberia, West Africa

Simian immunodeficiency virus (SIV) is a Lentivirus that exhibits both morphological and genomic similarities to HIV. SIV has been isolated from sooty mangabeys in several primate colonies, and has been shown to be about 80% related to HTV-2. Since HIV-2 and sooty mangabeys are both indigenous to West Africa, isolation of a virus from sooty mangabeys in West Africa would be of great interest in determining the origins of these two viruses. We report here thin section transmission electron microscopy of a lentivirus from a pet sooty mangabey living in Liberia, West Africa.Peripheral blood mononuclear cells (PEMC) from a healthy pet sooty mangabey in Liberia were frozen in liquid nitrogen and shipped to the California Primate Research Center. The cells were thawed and stimulated for 72h with 0.5μg/ml Staphylococcal enterotoxin A in RPMI 1640 containing 10% fetal calf serum. 2×106PEMC were then co-cultivated with 2×106CEMxl74 cells and processed for EM.CEMxl74 cells co-cultivated with infected PBMC exhibited syncytial giant cells with patchy foamy cytoplasm (Fig 1). large numbers of virus particles were observed within these vacuoles (Fig 2).

Measles associated with coronary arteritis

A two-year-old girl with measles virus (MV) and chronic Epstein-Barr virus (EBV) infection developed lethal coronary aneurysmal arteritis accompanied by giant cell pneumonia, systemic lymphadenitis and hepatosplenomegaly. In her coronary arteries, lungs and aorta, cells containing intranuclear and intracytoplasmic inclusions, including syncytial giant cells, were detected, the presence of MV in the organs being proved by electron microscopic and immunofluorescent studies. Immunopathology further demonstrated MV to be disseminated in almost all organs other than lymph nodes. Clinical diagnosis of chronic EBV infection was established on the basis of persistent high titers of antibodies against capsid and early antigens of EBV and viral presence was confirmed by Southern blot hybridization in a mesenterial lymph node obtained at autopsy. To the best of our knowledge, this is the first description of MV association with coronary aneurysmal arteritis, raising the possibility that measles infection can cause severe vasculitis under immuno-suppressive states, such as that caused by chronic EBV infection.

Recurrent Male Herpes Genitalis with Two Different Strains of Herpes Simplex Virus Type 2

A case of a 50-year-old man with recurrent herpes genitalis with two different isolated strains of herpes simplex virus (HSV) type 2 is reported. Morphologically, two types of cytopathic effects (CPE) induced by viruses were observed in the Vero cell cultures, one being a syncytial giant cell formation and the other a rounded cell formation without cell adhesion resembling the CPE induced by ordinary HSV type 2. In this case, it is clinically interesting that the patient complained of persistent pain on the glans and urethra without recurrence of herpetic lesions even after the involution of enanthema. The correlation between the persistent pain and neurovirulence of the two different HSV strains is discussed.

Demonstration of Respiratory Syncytial Virus in an Autopsy Series

Respiratory syncytial virus (RSV) antigen was demonstrated in formalin-fixed, paraffin-embedded autopsy tissue using an immunoperoxidase technique. Eighteen autopsy cases were selected on the basis of one of the following criteria: a positive culture for RSV, antemortem or postmortem; positive ELISA test for RSV, antemortem or postmortem; or postmortem histology suggestive of paramyxovirus infection. Controls included three cases from which parainfluenza or influenza virus had been cultured and a case in which the clinical diagnosis of measles was firmly established. Sections of formalin-fixed, paraffin-embedded tissue were stained with a rabbit anti-RSV antibody (Dako) using an immunoperoxidase technique. Staining was achieved in 12 cases. This included 6 of 7 cases selected because of positive cultures or ELISA tests for RSV. The other 6 cases in which RSV was identified by the described technique lacked culture or ELISA confirmation. Granular and globular staining was seen in the cytoplasm of respiratory epithelial cells and syncytial giant cells. None of the control cases stained for RSV. The histology of RSV lungs was consistent with changes described in the literature for RSV infection, although pneumonic consolidation and syncytial giant cells were more prominent in this series.

Occurrence of a canine distemper-like disease in aquarium seals.

Outbreaks of a canine distemper-like acute disease brought high mortalities to seal populations in north-west Europe and Lake Baikal from late 1987 to 1988. During these outbreaks three seals which were introduced from Lake Baikal to an aquarium in Japan developed a distemper-like disease and other seals raised in the same room were similarly affected. Clinical signs of dead seals were anorexia, diphasic fever, dyspnea, and neuromuscular tics. Characteristic microscopic lesions of acute interstitial pneumonia seen in the lung were accompanied with hyperplasia and syncytial giant cell formation of type II pneumocytes. Eosinophilic intranuclear and cytoplasmic inclusion bodies were present in bronchial epithelial cells, type II pneumocytes, epithelial cells of bile ducts and interlobular ducts of pancreas, transitional epithelium of renal pelvis, and reticular cells of lymph nodes. Ultrastructure of inclusion bodies was similar to that seen in cells infected with morbilliviruses. Serum samples from recovered seals had virus-neutralization antibodies against canine distemper virus. The present cases were the first report of morbillivirus infection of aquarium seals in Japan.

Spectrum of disease in macaque monkeys chronically infected with SIV/SMM

Twelve rhesus and one pig-tailed macaque have been monitored for 28–41 months following experimental infection with 10 4 TCID of SIV/SMM. Twelve of the 13 animals became virus positive and seroconverted within 3 to 6 weeks of exposure; the remaining animal seroconverted at 6 months, but has remained virus negative. Six of the 13 animals (46%) died between 14 and 28 months post-infection, following prolonged clinical disease characterized by chronic diarrhea and weight loss, peripheral lymphadenopathy and hemogram abnormalities. Histologic findings ranged from prominent follicular hyperplasia to severe lymphoid depletion, with lymphoid tissues often showing an infiltrate of syncytial giant cells. One animal had intestinal cryptosporidiosis and two had brain lesions comparable to those seen in AIDS encephalopathy in humans. Three of the remaining seven animals have an ARC-like disease and are showing gradual deterioration of their clinical condition. These animals, as well as animals that died, had progressive decreases in CD4 + cells and CD4 +/CD8 + cell ratios. These observations further document the marked clinical, pathologic and immunologic similarities between human AIDS and the SIV-infected macaque model.

Lymphomatoid granulomatosis and malignant lymphoma of the central nervous system in the acquired immunodeficiency syndrome

While primary and secondary malignant lymphomas have been well-documented in the CNS of patients with the acquired immunodeficiency syndrome (AIDS), only one case of lymphomatoid granulomatosis (LG) involving the CNS has been reported. We present three AIDS patients with multiple grossly evident foci of necrosis in the cerebral hemispheres which, on histologic evaluation, were seen to contain angiocentric mixed chronic inflammatory infiltrates with atypical mononuclear cells, luminal thrombosis, and infarction, which is typical of LG. LG was also identified in sections of the lung in one case. Lymphoma was found in other regions of the brain in two cases, suggesting the evolution of LG into cerebral lymphoma. In addition, widespread perivascular multinucleate syncytial giant cells, associated with human immunodeficiency virus (HIV) infection of the CNS, were identified in all patients. The features of LG, its relationship to lymphoma, and the possible etiologic role of an immunodeficiency state or the HIV virus in the pathogenesis of LG are discussed.

Placenta Creta and Placenta Praevia Creta

The placental bed in placenta creta and placenta praevia creta was studied from pregnancy or immediate postpartum hysterectomy specimens. In all cases placental villi were seen in direct contact with myometrium, the sine qua non of placenta creta, but was focal in some cases. There was no apparent diminution of decidua parietalis or, in cases of focal accreta, of adjacent basalis. In all cases the extravillous trophoblast was mainly uninuclear or binuclear, in contrast to the placental bed syncytial giant cells seen in late normal placentation. There was an apparent proliferation of interstitial trophoblast at the junction of placenta with myometrium, but the density of interstitial trophoblast deeper in the myometrium was lower than it is in normal placentation. An unusual uteroplacental vasculature was seen in which physiological changes were present in large arteries of the radial/arcuate system deep in the myometrium, while there were also spiral arteries more superficially without physiological changes. These findings suggest that in placenta creta there is defective interaction between maternal tissues, particularly decidua, and migratory trophoblast in the early stages of placentation resulting in undue adherence of the placenta or penetration into the uterus coupled with the development of an abnormal uteroplacental circulation.

Placenta creta and placenta praevia creta

The placental bed in placenta creta and placenta praevia creta was studied from pregnancy or immediate postpartum hysterectomy specimens. In all cases placental villi were seen in direct contact with myometrium, the sine qua non of placenta creta, but was focal in some cases. There was no apparent diminution of decidua parietalis or, in cases of focal accreta, of adjacent basalis. In all cases the extravillous trophoblast was mainly uninuclear or binuclear, in contrast to the placental bed syncytial giant cells seen in late normal placentation. There was an apparent proliferation of interstitial trophoblast at the junction of placenta with myometrium, but the density of interstitial trophoblast deeper in the myometrium was lower than it is in normal placentation. An unusual uteroplacental vasculature was seen in which physiological changes were present in large arteries of the radial/arcuate system deep in the myometrium, while there were also spiral arteries more superficially without physiological changes. These findings suggest that in placenta creta there is defective interaction between maternal tissues, particularly decidua, and migratory trophoblast in the early stages of placentation resulting in undue adherence of the placenta or penetration into the uterus coupled with the development of an abnormal uteroplacental circulation.

Immunity, viral pathology and assessment of immune dysfunction in virology and toxicology.

General patterns of tissue injury are recognized as characteristic for certain groups of viruses and certain types of host/virus interactions. Acute viral infections, limited in time and space, tend to be accompanied by florid but brief virus replication cycles in tissues and lesions or signs of disease are largely attributable to the cytolytic effects of the virus on host cells. Chronic or persistent viral diseases tend to have low (or difficult to detect) levels of infectious virus on tissues and the lesions tend to be dominated by inflammation, antiviral immune responses and/or host tissue proliferation. At the cellular level, 3 general categories of response to viral infection are recognized: acute cellular swelling with eventual cytolysis, persistent infection, and transformation (neoplastic) infection. Acute cellular swelling may be accompanied by syncytial giant cell formation and/or viral inclusion bodies. Cells persistently infected with viruses though morphologically normal, are increasingly recognized as functionally deficient and may eventually display degenerative change. Transformation to neoplastic growth can be both benign or malignant in cellular expression. In vivo, the initial neutrophilic inflammatory response to virus-induced cellular necrosis is transient and is rapidly superseded by virus-specific inflammation mediated by both humoral and cellular factors and supplemented by the numerous inflammation amplification pathways. Vasculitis, a common but frequently unappreciated event, may produce nonspecific tissue damage via hemorrhage and ischemia in addition to providing a mechanism for egress of inflammatory factors into the areas of virus-induced cellular damage. During the healing phase, repair by substitution (e.g., fibrosis and scarring) or by proliferation of uninfected replacement cells may dominate sites of viral infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Biodegradation of and tissue reaction to 50:50 poly(DL-lactide-co-glycolide) microcapsules.

The biodegradation of the copolymer 50:50 poly(DL-lactide-co-glycolide)-lypressin microcapsules was studied by light and electron microscopic methods and 14C release. Intramuscular injection sites of microcapsules in rats were studied by dissecting and conventional light microscopy as well as scanning (SEM) and transmission electron microscopy. A minimal localized acute myositis was seen initially at the injection sites. By Day 4, a few small foreign body giant cells were present participating in the minimal foreign body response. Later the inflammatory cells decreased and the individual microcapsules were walled off by immature fibrous connective tissue and large syncytial foreign body giant cells. By Day 35, definitive changes in some microcapsules, consisting of a granular and slightly eroded appearance of the internal matrix, were seen by SEM. By Day 42, the outer rims of the microcapsules were extensively eroded. At Day 56, the inflammatory and connective tissue reactions were almost completely resolved and biodegradation continued so that only remnant pieces of the microcapsules were present at Day 63. The morphologic picture correlated well with loss of 14C radioactivity, which could no longer be detected at the injection sites on Day 56. Phagocytosis did not seem to be an important factor in the biodegradation.

Detection of herpesvirus cervicovaginitis by a sequential papanicolaou‐immunoperoxidase technique

Herpes simplex virus (HSV) infection constitutes an immediate threat to the neonate of pregnant women who deliver vaginally, and thus requires a rapid, specific means of diagnosis that is easily applicable to cervicovaginal smears. We applied the peroxidase-antiperoxidase technique to variously fixed, previously stained Papanicolaou smears from 60 women with HSV and 18 negative controls using an HSV-2 antibody and either diaminobenzidine (DAB) or aminoethylcarbazol (AEC) as the chromogen and Mayer's, Gill's, or Lillie-Mayer's hematoxylin as the counterstain. With Papanicolaou stain alone, there was adequate cytologic demonstration of either single cells in aggregates (11%), syncytial giant cells (40%), or both (49%) that displayed a ground-glass appearance (68%), discrete nuclear inclusions (5%), or both (28%). With the peroxidase-antiperoxidase technique, 57 of the 60 HSV specimens (95%) stained moderately or strongly positive for HSV-2, as did sections of herpetic encephalitis and esophagitis. There was no false-positive staining in any of the 18 control smears revealing koilocytosis, Chlamydia, or nonspecific vaginitis. Positivity of the immunostain was more vivid and evenly dispersed through-out the cytoplasm with AEC than with DAB, but tended to wash away with alcohol-based counterstaining. In contrast, DAB was more stable, but was positive predominantly at the cell periphery and cytoplasmic processes. Lillie-Mayer's stain provided the best counterstaining for the cytologic visualization of virocytes and accompanying inflammatory and epithelial cells, which revealed a minimal degree of atypia. The fixative used had no influence on the frequency or degree of immunopositivity of virocytes, but wet fixation with 95% alcohol or Carbowax led to less background staining than Spray-Cyte.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunohistochemical and radioimmunological determination of beta-HCG and pregnancy-specific beta 1-protein in seminomas.

38 pure and 11 mixed seminomas were studied with the peroxidase-anti-peroxidase method for the presence of chorionic gonadotropin (beta-HCG) and pregnancy-specific beta 1-glycoprotein (SP1). HCG was found in 8 of 49 cases, SP1 in 5 of 49 cases in syncytial and mononuclear giant cells. The 5 pure seminomas with positive tumor markers appear to have no worse prognosis than pure seminomas without HCG or SP1 production. None of the seminomas was found to contain carcinoembryonic antigen or alpha-fetoprotein.

Infection of human endothelial cells by human T-lymphotropic virus type I.

We studied the effects of human T-lymphotropic virus type I (HTLV-I) on human endothelial cells in vitro. During cocultivation with an HTLV-I producer cell line (C91/PL), endothelial cells formed characteristic multinucleated syncytial giant cells. Inoculation with concentrated cell-free supernatant fluid from C91/PL cultures produced similar cytopathic effects, which were neutralized by pretreatment with HTLV-I specific human serum. HTLV-I antigens were detected in the cytoplasm of the multinucleated cells by indirect immunofluorescence. When endothelial cells showed maximal cytopathic changes, reverse transcriptase activity was demonstrated in the supernatant fluid and HTLV-I was isolated by cocultivation with peripheral blood mononuclear cells. This study demonstrates that HTLV-I tropism is not limited to lymphoid cells but extends to human endothelial cells as well.

Primary choriocarcinoma of the urinary bladder in association with undifferentiated carcinoma

A carcinoma of the urinary bladder with a distinct choriocarcinomatous component that developed in a postmenopausal woman was associated with high titers of circulating chorionic gonadotropin. The diagnosis was supported by histochemical demonstration of human chorionic gonadotropin in syncytial tumor giant cells and electron microscopic features consistent with syncytiotrophoblastic cell differentiation.

Clinical and pathological observations on spontaneous bovine respiratory syncytial virus infections in calves

A clinical, pathological and microbiological study was made of acute spontaneous bovine respiratory syncytial virus infection in calves. Characteristic features were atelectatic areas, which had an exudative and, or, necrotising bronchiolitis with syncytial giant cells in the epithelial lining and in the lumina of these bronchioles. Restricted to these areas both bronchiolar and alveolar immunofluorescence for bovine respiratory syncytial virus were seen. Complications were severe interstitial oedema, interstitial emphysema and a catarrhal or fibrinous pneumonia due to secondary bacterial invasion.

Distribution of tumor-associated antigens in the various histologic components of germ cell tumors of the testis.

The various histologic components of 39 germ cell tumors of the testis were studied with indirect labeled immunoperoxidase technique for the presence of the following tumor-associated antigens: alpha-fetoprotein (AFP), alpha 1-antitrypsin (A1AT), chorionic gonadotropin (HCG), specific pregnancy beta 1-glycoprotein (SP1), human placental lactogen (HPL), carcinoembryonic antigen (CEA), and ferritin (Fe). Embryonal carcinoma components were positive for AFP in 9/16, for A1AT in 6/16, for CEA in 2/16, and for Fe in 14/16. All yolk-sac tumor components were positive for AFP and Fe, and 8/13 contained A1AT and 2/13 CEA. Epithelium in teratoid components was positive for AFP in 5/14 cases, for A1AT in 8/14, for CEA in 7/14, and for Fe in 8/14. Syncytial trophoblast in choriocarcinoma components and syncytial giant cells were all positive for HCG, SP1 and HPL. In addition, tumor giant cells in two nonseminomatous tumors and in one seminoma contained HCG. Otherwise, all pure seminomas were negative for all antigens, except for Fe, which was positive in 12/16 cases. Demonstration of this functional aspect of germ cell tumors of the testis may clarify problems of classification and elucidate histogenesis. Furthermore, immunohistochemical demonstration of tumor-associated antigens is of value in the management of the patient as an indicator of which tumor markers should be used for monitoring the treatment. In addition, the presence of tumor-associated antigens may be used in prognostic evaluation.