Chronic Ulcerative Dermatitis Research Articles

Historical Control Data of Spontaneous Pathological Findings in C57BL/6J Mice Used in 18-Month Dietary Carcinogenicity Assays.

A retrospective analysis in C57BL6/J mice used in dietary carcinogenicity studies was performed to determine the survival rate, causes of death and incidences of spontaneous non-tumoral and tumoral findings. Data were collected from 1600 mice from control dose groups of sixteen 18-month carcinogenicity assays performed between 2003 and 2021 at the same test facility with similar environmental conditions and experimental procedures. The survival rate was high in both sexes (81%-85%) and the causes of humane euthanasia or death were mainly non-tumoral (chronic ulcerative dermatitis, atrial thrombosis). Benign tumors were more frequent than malignant tumors and females were more affected than males. Pituitary gland adenoma in females, lymphoma, bronchioloalveolar adenoma, and harderian gland adenoma in both sexes were the most common tumors. Systemic amyloidosis, the most frequent non-tumoral lesion, was observed variably across studies without sex predilection. The analysis by cohort (3 time periods of 6 years) showed a tendency toward higher incidences of lymphoma and pituitary gland adenoma and lower incidences of amyloidosis over time. The results presented here provide for the first time a robust set of control historical data in untreated C57BL/6J mice kept for 18 months contributing to build in depth knowledge of this animal model.

Stephanofilariasis in Holstein Cows - Diagnostic Approach In Southern Brazil

Background: Stephanofilariasis is a parasitic disease caused by the nematode Stephanofilaria spp., considered a zoonotic disease, that affects several species, mainly dairy cattle. The condition causes chronic ulcerative dermatitis, due to the mechanical action of the parasite on the hair follicles and dermal papillae. The recommended diagnostic method is histopathological examination, but alternative methods have been studied for the detection of the agent since it does not demonstrate good results. There is no specific treatment, however, the use of organophosphates is recommended. The objective of this work is to report an outbreak of stephanofilariasis with unusual lesions in cattle from a dairy cattle farm in the city of Boa Vista do Buricá, RS, Brazil, as well as to demonstrate an alternative method for the diagnosis of the disease. Cases: We prospectively evaluated 15 Holstein cows, aged between 1 and 10-year-old whose data and materials for diagnosis, were provided by the property owner. The outbreak occurred in the summer, in a period of greater rainfall, affecting cows of different ages and totaling 48% of the herd. These showed ulcerative lesions on the skin of the groin, limbs and interdigital regions, and less frequently in the udder. The samples were obtained through tissue biopsy and scraped from the lesions, being packed in 10% formaldehyde for fixation. Afterward, the formaldehyde was centrifuged at 800 g for 5 min, which consisted of analyzing the sediment through optical microscopy and without staining, aiming at the direct search of the agent. The tissues, on the other hand, underwent routine processing and stained with Hematoxylin and Eosin. Histopathological analysis did not reveal Stephanofilaria sp. subjects in morphological analysis and revealed acanthosis, spongiosis, ulcers and fibrosis in the analyzed tissue. The examination of direct research with formaldehyde proved to be efficient, and fast. In the direct examination of the agent, structures similar to filarial and compatible with Stephanofilaria sp. in all samples. Thus, the present study demonstrated that filariasis can present in the form of outbreaks and with unusual injuries. The examination of direct research with formaldehyde, proved to be efficient and fast. Discussion: Semi-confined and confined animals may have a higher occurrence of strephanofilariasis, since the parasite needs humid and warm environments to proliferate and that, the proliferation of stephanophilariasis vectors is intensified in environments with low sunlight, high temperatures, high humidity, and low cleaning frequency. The city of Boa Vista do Buricá, where the outbreak occurred, reached a minimum average temperature of 18.5ºC and an average of 29ºC, with an average rainfall of 120.5 mm. Cutaneous lesions have been seen in animals from 1 to 10 years of age and no racial predisposition, age, or blackout stage is reported. The histological diagnosis, although mentioned as a form of diagnosis, has low efficacy in finding parasites in the tissue, is also used as a diagnosis, direct examination of the agent with saline solution, and impression of the lesion stained by the Romanoswsky method. However, in this report, formaldehyde proved to be a new option, as efficiently as saline. Keywords: filariasis, flies, nematode, dairy cattle, zoonotic disease, direct examination, lactation ulcer.

A case of ex vivo boosted immune cell therapy for chronic ulcerative dermatitis in a dog

A 13-year-old castrated male Shih Tzu was presented with recurrent otitis externa and ulcerative dermatitis. Previous investigations had failed to identify the cause, and the lesion was resistant to treatment. According to the histopathological examination, a tentative diagnosis of chronic ulcerative dermatitis with bacterial infection was made. To treat the patient, immune cell therapy with antibiotics was conducted every 2 weeks, for a total of six sessions. After treatment, the skin lesion resolved. No side effects were observed during therapy. To the best of our knowledge, this is the first case report of the use of immune cell therapy for canine ulcerative dermatitis.

Superficial Chronic Ulcerative Dermatitis (SCUD) in Psittacine Birds: Review of 11 Cases (2008-2016).

We reviewed 11 cases of superficial chronic ulcerative dermatitis (SCUD) in psittacine birds that presented to an exotic animal practice over an 8-year period. African grey parrots ( Psittacus erithacus) were overrepresented, accounting for 55% of SCUD-affected birds. All affected birds were hand-reared pets and bonded strongly to their owners. In all cases, fungal culture results were negative. The most commonly cultured bacteria were Enterobacter cloacae (27%), followed by Escherichia coli, and Staphylococcus aureus (both 18%). An underlying cause of behavioral self-mutilation with secondary infection of dermatitis lesions by opportunistic bacteria was suspected in 10 of 11 cases. The axillae were the most common anatomic sites affected (45%). In two cases, more than one site was affected concurrently. Mean age of birds affected was 11.4 years. Two birds had suffered from SCUD previously, with 1 bird having suffered from 3 previous episodes and was euthanized as a result. All birds were treated with systemic antibiotics, topical antibacterial preparations, and systemic nonsteroidal anti-inflammatory drugs. A neck collar was applied in all cases. Median time to clinical resolution was 2 months (range, 1-21 months). Excluding the bird that was euthanized, all birds showed a positive response to treatment.

Activity of prolidase isoenzymes in the rat brain: Subcellular and regional distribution during development

Prolidase deficiency is characterized by chronic ulcerative dermatitis, mental retardation, and frequent infections. In the present study we examined the characteristics of rat brain prolidase isoenzymes. Prolidase isoenzymes (PD I and PD II) were isolated from the rat brain using DEAE cellulose column chromatography. PD I showed higher activity against seryl-proline and alanyl-proline, while PD II was particularly active against methionyl-proline. Prolidase activity in the whole brain and in the different brain regions showed higher activity against methionyl-proline and seryl-proline. PD II activity was highest in the hippocampus, followed by the cerebellum, cerebral cortex, caudatum, and the midbrain. The most rapid changes in the activities of PD I and PD II occurred perinatally, with a peak at three days before birth and a nadir at two days after birth, which then gradually increased until 21 days. N-benzyloxycarbonyl-l-proline inhibited PD I activity against various substrates in a dose-dependent manner. In contrast, there was no inhibition of PD II activity against methionyl-proline at low concentrations. In summary, these data suggest that maintenance of levels of proline, other amino acids and peptides containing proline in the rat brain is regulated by prolidase isoenzymes. The age-related alterations in PD I and PD II also may help to elucidate the fundation of prolidase isoenzymes in brain nervous system.

Fractionated, Low-Dose-Rate Ionizing Radiation Exposure and Chronic Ulcerative Dermatitis in Normal andTrp53Heterozygous C57BL/6 Mice

The influence of low-dose-rate chronic radiation exposure and adaptive responses on non-cancer diseases is largely unknown. We examined the effect of low-dose/low-dose-rate fractionated or single exposures on spontaneous chronic ulcerative dermatitis in Trp53 normal or heterozygous female C57BL/6 mice. From 6 weeks of age, mice were exposed 5 days/week to single daily doses (0.33 mGy, 0.7 mGy/h) totaling 48, 97 or 146 mGy over 30, 60 or 90 weeks, and other Trp53+/- mice were exposed to a single dose of 10 mGy (0.5 mGy/min) at 20 weeks of age. The 90-week exposure produced an adaptive response, decreasing both disease frequency and severity in Trp53+/+ mice and extending the life span of older animals euthanized due to severe disease. The 30- or 60-week exposures had no significant protective or detrimental effect. In contrast, the chronic, fractionated exposure for 30 or 60 weeks significantly increased the frequency and severity of the disease in older Trp53+/- mice, significantly decreasing the life span of the animals required to be euthanized for disease. Similarly, the single 10-mGy exposure also increased disease frequency in older animals. However, the chronic, fractionated exposure for 90 weeks prevented these detrimental effects, with disease frequency and severity not different from unexposed controls. We conclude that very low-dose fractionated exposures can induce a protective adaptive response in both Trp53 normal and heterozygous mice, but that a lower threshold level of exposure, similar in both cases, must first be passed. In mice with reduced Trp53 functionality, doses below the threshold can produce detrimental effects.

T Cell Requirement for Development of Chronic Ulcerative Dermatitis in E- and P-Selectin-Deficient Mice

T Cell Requirement for Development of Chronic Ulcerative Dermatitis in E- and P-Selectin-Deficient Mice

T cell requirement for development of chronic ulcerative dermatitis in E- and P-selectin-deficient mice.

C57BL/6 mice deficient in E- and P-selectin (E(-/-)P(-/-)) kept under specific pathogen-free barrier conditions have high circulating neutrophil counts and develop hypercellular cervical lymph nodes with substantial plasma cell infiltrates, severe ulcerative dermatitis, conjunctivitis, and lung pathology, which eventually lead to premature death. To test the hypothesis that the pathology in E(-/-)P(-/-) mice may be caused by dysfunctional lymphocyte activity, we crossed E(-/-)P(-/-) mice with recombination activation gene (Rag)-1(-/-) mice to generate E(-/-)P(-/-)Rag-1(-/-) mice lacking mature T and B lymphocytes. E(-/-)P(-/-)Rag-1(-/-) mice had circulating neutrophil counts and plasma G-CSF levels similar to E(-/-)P(-/-) mice. Remarkably, none of the E(-/-)P(-/-)Rag-1(-/-) mice developed conjunctivitis or ulcerative dermatitis typical of E(-/-)P(-/-) mice. These mice were overall healthier in appearance than E(-/-)P(-/-) mice, and histopathologic changes in the lung were reduced. Cervical lymph nodes in E(-/-)P(-/-)Rag-1(-/-) mice were much smaller than those of E(-/-)P(-/-) mice, containing few mononuclear cells and no plasma cells. These data show that the severe disease phenotype of E(-/-)P(-/-) mice depends on lymphocyte function. We conclude that a dysregulated immune response in E(-/-)P(-/-) mice causes disease development, but is not necessary for elevated neutrophil counts.