Adhesion and releasing of Poliovirus to activated sludge of wastewater purifying plants.

Pathogenic enteric viruses are released from infected persons through domestic wastewater to the environment. From that point of view, the knowledge of the viral behavior in wastewater purifying process is important: it is, however, still poorly understood. In this study, we reported the adhesion of Poliovirus to activated sludge samples taken from wastewater purifying plants by using a model system. More than 10(6) particles adhered to one gram (wet) of activated sludge, and the adhered viral particles maintained infectivity for longer period of time and showed higher thermo-resistant than the free viral particles. The adhered viral particles were released by increase of salt concentration or alkaline pH buffer as infectious particles. The data suggest that pathogenic viruses could be enriched and maintain the infectivity in the activated sludge, and released to environments under certain conditions.

In vitro migratory responses of swine neutrophils to actinobacillus pleuropneumoniae.

Swine neutrophils were quantitatively examined for the direct and indirect migratory responses to Actinobacillus pleuropneumoniae (APP) in vitro and the effects of pseudorabies virus (PrV), frequently co-infecting with APP, were also observed. About 30% of swine neutrophils responded to viable APP, while 3.2% of the neutrophils responded to 0.1% casein which served as the control. The migration of APP was not affected by preincubation of neutrophils with PrV, which inhibited the random migration. When the random migration was normalized to 1, the chemotactic indices for APP, opsonized-APP and casein were 64, 70 and 8.5, respectively. Heat-killed APP or E. coli lipopolysaccharide stimulated the production of interleukin-8 activity by adherent peripheral blood mononuclear cells (PBMC). Preincubation of PBMC with PrV inhibited the production of neutrophil attractant activity when stimulated with heat-killed APP. The results suggested that the direct chemotaxis of neutrophils to viable APP might contribute to early infiltration in Actinobacillus pleuropneumonia, and that PrV might inhibit indirect recruitment of neutrophils to infected lungs by compromising the functions of PBMC.

Influences of alkaline ionized water on milk electrolyte concentrations in maternal rats.

We previously reported that body weight on day 14 after birth in male offspring of rats given alkaline ionized water (AKW) was significantly heavier than that in offspring of rats given tap water (TPW), but no significant difference was noted in milk yield and in suckled milk volume between the two groups. Additionally, the offspring in the AKW group and TPW group were given AKW and TPW, respectively, at weaning, and unexpectedly, the necrotic foci in the cardiac muscle were observed at the 15-week-old age in the AKW group, but not in the TPW group. The present study was designed to clarify the factors which are involved in that unusual increase of body weight and occurrence of cardiac necrosis. Eight dams in each group were given AKW or TPW (control) from day 0 of gestation to day 14 of lactation. The milk samples were collected on day 14 of lactation and analyzed for concentrations of calcium (Ca), sodium (Na), potassium (K), magnesium (Mg) and chloride (Cl). The AKW and TPW were also analyzed. Ca, Na and K levels in milk were significantly higher in the AKW group compared to the TPW group. No significant difference was noted in the Mg and Cl levels between the two groups. These data suggested that the Ca cation of AKW enriched the Ca concentration of the milk and accelerated the postnatal growth of the offspring of rats given AKW.

Prompt recovery of damaged adrenal medullae induced by salinomycin.

The morphologic changes in the adrenal medullae of rats treated with an ionophore antibiotic, salinomycin, are described. Male rats of approximately 7 wk of age were treated orally with a single dose of salinomycin at 80 mg/kg body weight. Following this treatment, the adrenal glands were examined, using immunohistochemistry, for neurofilament, laminin, fibronectin, and S-100 protein; the glands were also examined using transmission electron microscopy. One hour after the treatment, a karyopyknosis was observed in the clusters of affected chromaffin cells in which the neurofilament, laminin, and fibronectin were present. The lesions became progressively conspicuous between hours 5 and 10. Ultimately, the outcome was cell lysis. Five hours after salinomycin treatment, unaffected chromaffin cells strongly stained to tyrosine hydroxylase. At 10 hr, new chromaffin cells, which were irregular in shape with electron-dense cytoplasm (dark cell), that were strongly stained for tyrosine hydroxylase appeared at the basement membrane site of the necrotic clusters, and these cells contained very few immature catecholamine granules of less than 80 nm. At 17 hr, the catecholamine granules increased in number and size to about 200 nm. The newly formed chromaffin cells grew within the clusters to fill in the medulla by 24 hr, and cytoplasmic granules progressively increased in number and size. The interstitial tissue was seen to be edematous at 5 hr. New capillaries were found in the adrenal medullae of both control and salinomycin-treated rats. The protruding chromaffin cells (protruding cells), which we previously described in normal rats, were also observed in salinomycin-treated rats, which suggests that holocrine secretion is performed in the adrenal medullae. The results indicated that the rat adrenal medullae have the ability to make a rapid recovery after an insult by salinomycin.

Effect of heparin on hemagglutination by equine arteritis virus.

Heparin inhibited hemagglutination (HA) by equine arteritis virus (EAV) as well as did HA by Aujeszky's disease virus (ADV), but failed to inhibit HA by parainfluenza virus type 3 (PIV-3). The minimal concentration of heparin required to inhibit 8 HA U of EAV was 0.1 U/ml. In addition, most EAV hemagglutinin was retained by heparin acrylic beads, as was ADV hemagglutinin, but was not PIV-3 hemagglutinin. Mouse erythrocytes failed to combine with the HA inhibitory factor of heparin. However, mouse erythrocytes treated with heparinase had greatly reduced agglutinability by EAV. All these findings suggest that a heparin-like molecule on the surface of mouse erythrocytes serves as the virus-cell receptor.

Hemagglutination with crane herpesvirus.

A crane herpesvirus (CrHV) grown in chicken embryo fibroblast (CEF) cells was tested for hemagglutination (HA) with erythrocytes from a variety of species at 4 degrees C, room temperature and 37 degrees C. HA was observed at all temperatures with erythrocytes from mouse, ddY and BALB/c strains, but not with those from cattle, sheep and chicken. Mice, ddY strain, showed an individual variation in agglutinability of their erythrocytes and erythrocytes from BALB/c gave a higher HA titer. The HA activity was inhibited by the sera obtained from naturally infected cranes, experimentally infected duck and immunized rabbit with CrHV. HI antibody titers of these sera showed a closely positive correlation with their neutralizing antibody titers.

Neoplastic response in Japanese medaka and channel catfish exposed to N-methyl-N'-nitro-N-nitrosoguanidine.

Japanese medaka (Oryzias latipes) and channel catfish (Ictalurus punctatus) were investigated for carcinogenic response following a 28-day, 3 x/wk pulse exposure to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Five-wk-old medaka were exposed at concentrations of 0, 0.5, and 1.0 mg/L, and 5-mo-old catfish at concentrations of 0, 0.1, and 0.5 mg/L. In medaka, a total of 19 tumors including 2 branchioblastomas, 6 thyroid follicular adenomas and 1 adenocarcinoma, and 11 subcutaneous fibrosarcomas were observed in 16 of 96 MNNG-exposed fish. In catfish, a total of 37 tumors including 4 squamous cell carcinomas and 16 papillomas, 3 lipomas, 1 fibroma, 1 osteosarcoma, 4 branchioblastomas, 6 thymic epithelial tumors, and 2 generalized lymphosarcomas were observed in 34 of 172 MNNG-exposed fish. The induction of neoplasms in medaka was primarily in the gill, thyroid, and subcutis of the cervical and trunk regions, whereas in catfish skin, thymus, oro-pharynx, and hemopoietic tissues were also commonly affected. In both species, the neoplastic response was considered to be related to direct exposure of the tissues to MNNG. Some of these tumors have not been reported in the literature in either natural or experimental fish. The results also suggest species-specific differences in carcinogenic response following MNNG exposure.

A new type of cell death, the protruded type, observed in the adrenal gland of normal rats.

Apart from apoptosis, a type of parenchymal cell death by the cell protruding into the capillary lumen was observed in the adrenal gland of normal Sprague-Dawley rats. Ultrathin sections were prepared in the conventional manner and were examined by electron microscopy. The protruded cells (p-cells) had the electron lucent cytoplasm and the p-cells with ruptured cell membranes were observed in the capillaries. The egress of p-cells was either through the endothelial gaps, or following the rupture of capillary endothelia. The cytoplasmic matrices of the dying p-cells were seen to scatter in the capillary lumen where the nuclei, mitochondria and granules remained morphologically intact. The p-cells were seen in the capillaries of medulla, but restricted to those of zona reticularis in the cortex.

Spontaneous pulmonary squamous cell carcinoma in an aging CD rat.

Naturally occurring squamous cell carcinomas of lung of laboratory rodents are rare, and few cases have been reported and illustrated. A solid peripheral lung mass was observed grossly in a untreated 573-day-old male Sprague Dawley CD (Crl:CD [SD] BR) rat. Microscopically, the mass was composed of neoplastic squamous epithelial cells arranged in nests, cords, nodules, or solid sheets. Epithelial pearls were present. The mitotic index was high, and intercellular bridging (prickles) was noted. In some areas, neoplastic cells rimmed large cystic areas containing neutrophils, cell debris, and laminated keratin masses. Neoplastic cells had both expansive and invasive growth with entrapment of bronchioles and marked fibroplasia.

DNA relatedness among established Ureaplasma species and unidentified feline and canine serogroups.

The levels of DNA relatedness among two unclassified feline ureaplasma serogroups, four unclassified canine ureaplasma serogroups, and the three previously established Ureaplasma species were examined and compared. The strains examined included five feline strains representing two feline serogroups, four canine strains representing four canine serogroups, and the type strains of the three established species. Each strain representing each species or serogroup exhibited 78% or more actual DNA homology with its homologous DNA, but less than 10% DNA homology with DNAs from the heterologous strains. These findings indicate that each of these human, bovine, avian, feline, and canine strains is genomically distinct. In addition, the three previously recognized species (Ureaplasma urealyticum [human], Ureaplasma diversum [bovine], and Ureaplasma gallorale [avian]), which were established on the basis of phenotypic properties, were also shown to be genomically distinct. The three feline serogroup SI strains were genomically related (from 89 to 100% DNA homology) to each other but were unrelated (less than 10% DNA homology) to the feline serogroup SII strains, indicating that these two feline serogroups are also genomically distinct. Conversely, the two feline serogroup SII strains were genomically very similar (from 83 to 100% DNA homology) to each other but were unrelated (less than 10% DNA homology) to the three feline serogroup SI strains. However, canine serogroup SI strain D1M-C exhibited 73% DNA homology with serologically distinct canine serogroup SII strain D29M, indicating that these strains representing two separate serogroups belong to the same genomic species.(ABSTRACT TRUNCATED AT 250 WORDS)

A proposed life cycle model of Spiroplasma mirum based on scanning electron microscopical observations of growth in liquid culture.

Cells of Spiroplasma mirum strain SMCA were grown in PPG broth and examined by scanning electron microscopy. Comparison of the results at different time intervals allowed for a model of the life cycle of S. mirum to be proposed. Under favorable growth conditions, helical filament formation was initially observed, followed by the formation of small spherical structures originating from each filament. In old culture, large spherical bodies appeared from entangled helical filaments. From the larger spherical bodies, granular bodies representing the smallest reproductive units were produced to continue the life cycle.

Genomic analysis of avian and feline ureaplasmas by restriction endonucleases.

Genomic relationship among the strains of avian and feline ureaplasmas was determined by restriction analysis. Chromosomal DNAs extracted from the two avian and four feline ureaplasma strains resolved in 1.0% agarose gel electrophoresis following digestion with the restriction enzymes, PstI, BamHI, HindIII, EcoRI, SalI and HpaII. Relationship among the strains was determined from base substitution frequency obtained by comparing the restriction patterns. The guanine plus cytosine (G + C) contents of the representative strains of avian and feline ureaplasmas were estimated by high-performance liquid chromatography to be 27.6 and 27.1 mole %, respectively. Restriction patterns of the avian and feline ureaplasmas were distinct from those of the human and bovine strains, but they were relatively similar within a serotype.