Severity Of Microscopic Lesions Research Articles

Elemental and radionuclide exposures and uptakes by small rodents, invertebrates, and vegetation at active and post-production uranium mines in the Grand Canyon watershed

The effects of breccia pipe uranium mining in the Grand Canyon watershed (Arizona) on ecological and cultural resources are largely unknown. We characterized the exposure of biota to uranium and co-occurring ore body elements during active ore production and at a site where ore production had recently concluded. Our results indicate that biota have taken up uranium and other elements (e.g., arsenic, cadmium, copper, molybdenum, uranium) from exposure to ore and surficial contamination, like blowing dust. Results indicate the potential for prolonged exposure to elements and radionuclides upon conclusion of active ore production. Mean radium-226 in deer mice was up to 4 times greater than uranium-234 and uranium-238 in those same samples; this may indicate a potential for, but does not necessarily imply, radium-226 toxicity. Soil screening benchmarks for uranium and molybdenum and other toxicity thresholds for arsenic, copper, selenium, uranium (e.g., growth effects) were exceeded in vegetation, invertebrates, and rodents (Peromyscus spp., Thomomys bottae, Tamias dorsalis, Dipodomys deserti). However, the prevalence and severity of microscopic lesions in rodent tissues (as direct evidence of biological effects of uptake and exposure) could not be definitively linked to mining. Our data indicate that land managers might consider factors like species, seasonal changes in environmental concentrations, and bioavailability, when determining mine permitting and remediation in the Grand Canyon watershed. Ultimately, our results will be useful for site-specific ecological risk analysis and can support future decisions regarding the mineral extraction withdrawal in the Grand Canyon watershed and elsewhere.

The prevalence of ultrasonographic abnormalities and histopathologic lesions is high in testes of yearling tropical hair rams

Ultrasonography is commonly used to examine testes as part of a breeding soundness examination in sheep, especially, in cases of infertility or when gross testicular abnormalities are present. A descriptive, prospective, prevalence study was conducted to characterize the ultrasonographic, histopathologic, and spermatozoal morphology abnormalities present in a group of yearling tropic hair rams on the island of St. Kitts. Hyperechoic and shadowing abnormalities increased over a 6 month study period. Hyperechoic abnormalities were present in one or both testes in 89% (25/28) of yearling rams and 71% (40/56) of testes at castration. Shadowing abnormalities were present in one or both testes in 46% (13/28) of rams and 34% (19/56) of testes at castration. Shadowing was present more with moderate and severe hyperechoic abnormalities, with few testes in the mild category having any shadowing. As hyperechoic and shadowing abnormalities increased in severity, so did the severity of microscopic lesions including increased interstitial cellularity/fibrosis, interstitial mineralization, seminiferous tubules mineralization (hyperechoic only), and chronic lymphoplasmacytic orchitis. There were no spermatozoal morphologic abnormalities other than an increase in distal cytoplasmic droplets. The study findings detail a pathologic event in this group of yearling rams that has an unknown etiology. Potential causes may include scrotal insulation, trauma, infectious causes, immunity alterations, nutritional imbalances, and ingestion of a toxin. Further studies are required to elucidate the causative agent.

Neurological Changes in Horses Naturally Infected With Halicephalobus gingivalis

This paper aims to describe clinical and neuropathological changes in three horses naturally infected with Halicephalobus gingivalis in Brazil. Three cases of central nervous system (CNS) infection by H. gingivalis were selected, and archival (2003–2014) data (epidemiologic, clinical, and pathologic findings) were reviewed. The pattern, distribution, and severity of microscopic lesions in the CNS were determined. The main clinical signs in all horses included blindness, apathy, ataxia, and incoordination, which could be attributed to telencephalon, basal nuclei, and midbrain damage by migration of H. gingivalis. Thalamus/hypothalamus, hippocampus, and pons also presented significant lesions that could have contributed to proprioceptive dysfunction in all animals. The CNS changes in infected horses included severe multifocal necrotizing granulomatous meningoencephalitis characterized by gray and white matter perivascular infiltration with macrophages, multinucleate giant cells, a few eosinophils and lymphoplasmacytic cuffing within intralesional cross, and longitudinal parasitic sections. Reactive astrocytosis with strong antiglial fibrillary acidic protein immunolabeling surrounding damaged areas in the CNS was also detected. This report highlights the main CNS alterations caused by H. gingivalis infection and may contribute to the diagnosis of this disease in horses.

The Preventive Effects of Different Doses of Glucomannan on Experimental Aflatoxicosis in Japanese Quails

ABSTRACT This experimental study was performed to investigate whether there is a protective effect of different doses of Glucomannan using against aflatoxicosis in Japanese quail, and pathological changes and relative organ weights were compared. In the experiment, 60 one-day old male Japanese quails were used as divided into six different groups. Experimental groups were designated as Control(C), aflatoxin(A), glucomannan(GM), 2-fold dose of glucomannan(2GM), aflatoxin+glucomannan(A+GM) and aflatoxin+2-fold dose of glucomannan(A+2GM). While control group quails fed the standard ration as ad libitum, other groups were fed with the administrations additionally to standard diet respectively; 2mg/kg of aflatoxin to group A, 1g/kg of glucomannan to group GM, 2g/kg of glucomannan to group 2GM, 2mg/kg of aflatoxin and 1g/kg glucomannan to group A+GM, 2mg/kg of aflatoxin and 2g/kg glucomannan to group A+2GM. All quails were euthanized at day 21 of the study and organs, (liver, spleen, kidney, thymus and bursa of Fabricius) were removed, weighed and subjected to routine histopathological procedures. Although any important macroscopic changes were not observed in the C, GM and 2GM groups, significant pathological changes were found in the groups of A, A+GM and A+2GM. In the A+GM group, the partial reduction in the severity of microscopic lesions were seen in liver, bursa of Fabricius, thymus and spleen, however a significant reduction in severity of lesions was noticed in A+2GM group. As a result of the study, 2g/kg of glucomannan has been found pathologically to be more effective than 1g/kg glucomannan in terms of the protection against aflatoxicosis by giving orally.

OP088: Chronic restraint stress modifies global DNA methylation but not experimentally induced neoplastic lesions

Purpose To determine if experimentally induced chronic stress modifies expression of microscopic neoplastic lesions, cell proliferation, oxidative cell damage and global DNA methylation in CF-1 mice tongues exposed to chemical carcinogenesis and controls. Methodology Experimental study. Fourteen male CF1 mice were treated with 4-Nitroquinoline 1-oxide (4NQO), as well as induction of chronic stress usingmovement restriction method. Fourteen similar specimens were treated only with 4NQO; 14 identical animals received only movement restriction and 14 others received no treatment. 4NQO was administered in drinking water during 16 weeks. Restraint stress treatment was administered in four 21 day cycles, 45 min long. All animals were sacrificed after 30 weeks. Blood samples were obtained to analyze amount of circulating corticosterone. Tissue samples were obtained to determine presence or absence of microscopic neoplastic lesions (Acantosis, Dysplasia, Carcinoma); severity of microscopic lesions (Differentiation Degree, Tumor Invasion Front); and immunohistochemical Ki67 and 8OHdG expression. Finally, percentages of global DNA methylation were determined. Software’s SPSS Statistics v19 and GraphpadPrism 5 were used for statistical analyses. Results Corticosterone levels (p = 0.042); microscopic neoplastic lesions (Acantosis, p = 0.001; Dysplasia, p = 0.001; Invasive Carcinoma, p = 0.005); cell proliferation (p = 0.001); oxidative cell damage (0.001) and global DNA methylation (p = 0.037) showed statistically significant differences among all groups. Differences were not statistically significant when only 4NQO-treated groups were analyzed. Conclusions Movement restriction induced chronic stress modifies corticosterone levels and global DNA methylation; however, it does not influence the development of experimentally induced neoplastic lesions.

The comparative evaluation of cellular localization of viral antigens with microscopic changes in the ileum of cattle infected with bovine viral diarrhea

The correlation between microscopic changes with cellular localization of viral antigens was studied in the ileum of 16 cases infected with bovine viral diarrhea virus (BVDV). Microscopic lesions in the ileum included multifocal erosive and ulcerative ileitis, severe congestion and hemorrhage, crypt dilation and mucus engorgement, epithelial debris and leukocytes, lymphoid depletion of Peyer’s patches, herniation of mucosal epithelium into depleted Peyer’s patches, and fibrinoid vasculitis of submucosal vessels. BVDV antigen was detected by immunohistochemistry in macrophages, dendritic cells, smooth muscle cells, endothelial cells, epithelial cells of crypts, and mucosal epithelium, together with other mononuclear cells including lymphocytes, plasma cells, fibroblasts, and intramural ganglial cells. No consistent correlation between the presence of BVDV antigen and vascular lesions in the ileum was identified. The intensity and distribution of the immunoperoxidase stain in the ileum was graded as highly positive (18.7%), moderately positive (56.3%), and mildly positive (25%). In conclusion, the pattern and density of distribution and localization of BVDV antigen in the ileum was not consistently correlated with the severity of microscopic lesions.

Response of rainbow trout Oncorhynchus mykiss to exposure to Myxobolus cerebralis above and below a point source of infectivity in the upper Colorado River.

We exposed 9 wk old rainbow trout Oncorhynchus mykiss to ambient levels of Myxobolus cerebralis infectious stages at 4 sites of suspected differing infectivity in the Colorado River. Exposure was estimated by periodic filtration of river water at each exposure location. After a 32 d exposure, the fish were held in the Colorado River at a common site for over a year. Resulting infection was evaluated by the presence of clinical signs (whirling behavior, cranial deformity/exophthalmia, and black tail), severity of microscopic lesions, and myxospore counts (8, 10, 12, and 14 mo post-exposure). Two exposure sites that were immediately downstream of Windy Gap Reservoir were much higher in infectivity than the site above the reservoir or the site 26 km downstream of the reservoir. Rainbow trout exposed at those locations showed higher prevalence of clinical signs of whirling disease, more severe histological evidence of infection and higher average myxospore concentrations than those exposed above the reservoir or 26 km below the reservoir. Many more M. cerebralis actinospores were observed from water filtration at the 2 sites immediately below the reservoir compared to the other sites.

Salmonids Resistant toCeratomyxa shastaAre Susceptible to Experimentally Induced Infections withMyxobolus cerebralis

Two strains of rainbow trout Oncorhynchus mykiss and one strain of steelhead (anadromous rainbow trout) previously shown to demonstrate resistance to the myxosporean pathogen Ceratomyxa shasta were found to be susceptible to experimentally induced infections with the myxosporean Myxobolus cerebralis. Laboratory exposures to waterborne infectious stages (triactinomyxons) of M. cerebralis of both strains of rainbow trout and the steelhead resulted in clinical signs of whirling disease, including the characteristic tail chasing and black tail, approximately 42–49 d after exposure at a water temperature of 15°C. At 5 months postexposure, the severity of microscopic lesions and spore concentrations in the head cartilage of all salmonids resistant to C. shasta were evaluated. The Iron Gate steelhead and the Pit River rainbow trout that were resistant to C. shasta had lesion scores and spore counts similar to those of control rainbow trout known to be susceptible to C. shasta. Evidence of some resistance to M. cerebralis among the Deschutes River strain of rainbow trout was demonstrated by lower lesion scores and mean spore counts than were seen in the control rainbow trout strain. In general, however, the mechanisms of resistance that have developed among certain salmonid populations to one myxosporean, C. shasta, do not extend to protection or resistance to a second myxosporean, the causative agent of salmonid whirling disease.

Susceptibility of Three Species of Anadromous Salmonids to Experimentally Induced Infections withMyxobolus cerebralis, the Causative Agent of Whirling Disease

Abstract The susceptibility of three species of anadromous salmonids to whirling disease was examined after their experimental exposures to the infectious stages of Myxobolus cerebralis. Chinook salmon Oncorhynchus tshawytscha exposed as alevins were very susceptible to infection; the appearance of clinical signs, prevalence of infection, severity of microscopic lesions, and spore counts at 130 d postexposure are similar to those of age-matched rainbow trout O. mykiss exposed at the same dose. In contrast, coho salmon O. kisutch demonstrated no clinical signs of infection and had a lower prevalence of infection and spore numbers than did the exposed rainbow trout. A comparison of two strains of steelhead (anadromous rainbow trout), one from an enzootic site (San Lorenzo River) where M. cerebralis has been present for the past 35 years and a second from a site where the parasite is not found (Dry Creek), showed them both to be highly susceptible to experimental infections with M. cerebralis. These controll...

Radiographic and microscopic correlation of diffuse interstitial and bronchointerstitial pulmonary patterns in the caudodorsal lung of adult thoroughbred horses in race training.

Complete thoracic radiographic examinations were performed on 7 horses ranging in age from 24 to 60 months, followed by in-situ lung fixation. Radiographs were examined by 3 radiologists for the presence, degree and distribution of generalised pulmonary patterns within a region of interest in the caudodorsal lung. Pulmonary tissue was obtained from 12 sites within a designated volume of interest in the caudodorsal lung, corresponding to the area of interest evaluated radiographically, and examined for the presence, character and severity of microscopic lesions. Radiographic findings within the volume of interest consisted of mild to moderate bronchial, bronchointerstitial, or interstitial pulmonary patterns. Interstitial and bronchointerstitial radiographic findings were related to severity of peribronchiolar mononuclear cell infiltrates, the degree of bronchiolar mucosal plication, and alveolar capillary and peribronchial blood vessel erythrocyte content. The severity of the interstitial radiographic pattern was inversely associated with the perceived diagnostic quality of the radiographic examinations. There was no evidence of spatial variation in the severity of the microscopic changes examined in this limited pulmonary region. Inter-rater reliability between radiologists was good in the assessment of diagnostic quality of the radiographic examinations but poor in assessing severity of the primary generalised pulmonary patterns within the radiographic region of interest.

Immunohistochemical Detection of Infectious Bursal Disease Virus in Formalin-Fixed, Paraffin-Embedded Chicken Tissues Using Monoclonal Antibody

Immunoperoxidase and immunofluorescence techniques detected and localized infectious bursal disease virus (IBDV) in formalin-fixed paraffin-embedded sections of the bursa of Fabricius of experimentally and naturally infected chickens. The primary antibody was a monoclonal antibody that bound all IBDV serologic subtypes, including the GLS isolate. Both techniques were valuable in detecting IBDV. The presence and severity of microscopic lesions in the bursa correlated with the location and number of positive IBDV-infected cells as measured by either test. Mild vaccine strains induced minimal microscopic lesions and resulted in a few cells positive by either test. In contrast, virulent IBDV produced widespread lymphoid necrosis and numerous cells positive by both assays. The immunoperoxidase test was more useful than the immunofluorescence test, since the same section could be stained and examined by immunoperoxidase and then restained and examined for microscopic pathology. The presence of immunoperoxidase-positive stained cells associated with areas of microscopic pathology suggested that microscopic lesions were induced by IBDV.

Efficacy of Live Vaccines against Serologic Subtypes of Infectious Bursal Disease Virus

Experiments determined the efficacy of live vaccines in specific-pathogen-free broilers against serologic subtypes of infectious bursal disease virus (IBDV). Challenge isolates were the Delmarva variant E, a standard serotype I (APHIS) and a variant isolate from Mississippi. The vaccines were a cloned standard (CS) vaccine (Clone Vac-D78), a cloned variant (CV) vaccine (Bursa Vac IV), and an uncloned standard (UCS) vaccine (Bursine II). The severity of microscopic lesions was correlated with bursal atrophy as measured by bursa-weight-to-body-weight ratios. All vaccines provided adequate protection against the APHIS challenge. The three vaccines averaged 77% protection against APHIS in the first experiment and 78% in the second. Protection against the variant E and Miss isolates was considerably less for all vaccines. The three vaccines produced an average 70% protection against the Miss isolate in the first experiment and 69% in the second experiment. Against the variant E virus, the three vaccines averaged 67% protection in the first experiment and 65% in the second. There were significant differences in protection for each vaccine against individual IBDV subtypes. Results showed that no vaccine provided good protection (at least 80%) against all three subtypes of IBDV.

Effects of Cyclosporine A on Reovirus-Infected Broilers

The effect of cyclosporine A on reovirus-infected male broiler chickens was studied. Beginning at 1 or 10 days of age, 3 groups of 15 broilers were injected in the pectoral muscle with 50 mg of cyclosporine A (CSA) in oil per kg body weight every 3 days until 28 days. Controls were injected with olive oil. Two CSA-injected groups and one untreated group were orally infected with 1000 TCID50 of reovirus at 1 day of age. Cell-mediated immunity was evaluated at 17 and 24 days by a delayed-wattle-response test to injected phytohemagglutinin (PHA-M). Cyclosporine A and reovirus significantly (P less than 0.001) depressed the wattle response following the first injection of PHA-M but not the second. At necropsy 28 days postinoculation (PI), no gross lesions were apparent. Histologic lesions in birds infected with reovirus were lymphocytic pericarditis and tenosynovitis; synovial cells were hyperplastic, and heterophils and fibrin were in synovial spaces. Thymic medullary diameters were significantly (P less than 0.001) smaller in all CSA-treated birds. Although CSA suppressed cell-mediated immunity somewhat, there were no apparent differences in severity of microscopic lesions among reovirus-infected groups.

Pathogenesis of Infectious Bursal Disease in Chickens Infected with Virus at Various Ages

Chickens free from infectious bursal disease (IBD) maternal antibody were inoculated with a virulent strain of IBD virus at 1, 5, or 11 weeks of age. Chickens inoculated at 5 weeks developed severe clinical signs and had reduced levels of serum complement within 2-4 days postinoculation, but those inoculated at 1 or 11 weeks did not. However, at 1, 2, 4, and 8 days postinoculation, the rate of virus recovery from different tissues, severity of microscopic lesions, and frequency of detection of viral antigens in lymphoid organs of chickens inoculated at 5 weeks were comparable to those of chickens inoculated at 1 or 11 weeks of age. These findings suggest that age resistance to clinical manifestations of IBD is probably independent of the ability of virus to replicate and induce lesions in the host.