Uriel Blas-Machado

Effects of an Oral Contraceptive Combination With or Without Androgen on Mammary Tissues: A Study in Rats

Objectives: Oral contraceptive (OC) therapy has long been known to produce hypoandrogenemia. However, androgens are not part of any OC therapy available to women. This project was designed to evaluate the effects of low-estradiol containing OC, with or without methyltestosterone (MT), on cell proliferation and progesterone receptor (PgR) expression in mammary gland epithelia of virgin female rats. Methods: Sixty rats were divided into four groups. One group received OCs, whereas a second group received OC plus MT. A third group of rats was treated with an antiandrogen to mimic the hypoandrogenemic effects caused by OC therapy. All treated groups were compared with age-matched untreated controls. Results: After 15 weeks of treatment, no inflammatory, precancerous, or cancerous lesions were observed in any treatment group. OC plus MT therapy caused significant suppression of epithelial proliferation, a reduction in the number of proliferating cell nuclear antigen-labeled cells, and an increase in the number of PgR-labeled cells. Conclusions: Our results suggest that a medication containing an estrogen-progestin-androgen combination has antiproliferative effects in mammary glands of experimental animals that could prove to have breast-protective potential in women.

Bovine Viral Diarrhea Virus Type 2-Induced Meningoencephalitis in a Heifer

The brain from a 15-month-old, black female Angus, with a 48-hour history of central nervous system disease, was submitted to the Oklahoma Animal Disease Diagnostic Laboratory. Microscopic findings consisted of acute, multifocal meningoencephalitis, with neuronal degeneration and necrosis and gliosis. Viral isolation yielded noncytopathic bovine viral diarrhea virus (BVDV). Virus genotyping classified the virus as BVDV type 2. Immunohistochemical labeling for BVDV antigens with BVD MAb 3.12F1 clone was prominent in the cytoplasm of neurons, glial cells, ependymal epithelium, perivascular macrophages and spindle cells, smooth muscle cells, and intravascular monocytes of the cerebrum and brain stem. Laboratory results support that tissue alterations occurred as a result of BVDV type 2 infection. In the absence of other clinical signs related to BVDV infection and using the microscopic and laboratory evidence presented, we propose that the BVDV type 2 isolated from this case may represent a neurovirulent strain of the virus. To the best of our knowledge, this is the first report of brain lesions and neuronal viral antigen localization in BVDV genotype 2 viral infection, acquired either congenitally or postnatally.

Retrospective Study of Etiologic Agents Associated with Nonsuppurative Meningoencephalitis in Stranded Cetaceans in the Canary Islands

ABSTRACT Nineteen natural cases of etiologically undetermined encephalitides in free-ranging cetaceans were studied retrospectively. Histological examination of the brains revealed variable degrees of nonsuppurative encephalitis or meningoencephalitis, characterized predominantly by perivascular lymphohistiocytic infiltrates. A PCR assay was used on brain and other available tissues to detect the presence of morbillivirus, herpesvirus, West Nile virus, Toxoplasma gondii, and Brucella spp. In addition, immunohistochemical (IHC) staining was performed on selected tissues to determine the presence of morbilliviral antigens. Six animals (5 striped dolphins and 1 common dolphin) showed IHC and/or molecular evidence of morbilliviral antigens and/or genomes, mainly in brain tissue. Conventional nested PCR detected herpesviral DNA in brain tissue samples from two striped dolphins. There was no evidence of West Nile virus, T. gondii, or Brucella spp. in any of the brain tissue samples examined. The information presented here increases the number of confirmed morbillivirus-positive cases within the Canarian archipelago from two previously reported cases to eight. Furthermore, a new nested-PCR method for the detection of morbillivirus is described here. Regarding herpesvirus, the phylogenetic analysis performed in the current study provides valuable information about a possible pathogenic branch of cetacean alphaherpesviruses that might be responsible for some fatal cases worldwide.

Interleukin-10 modulates antigen presentation by dendritic cells through regulation of NLRP3 inflammasome assembly during Chlamydia infection.

ABSTRACT Interleukin-10 (IL-10) has been implicated in susceptibility to genital chlamydial infection and the development of tubal pathologies. IL-10 limitation also resulted in the rapid elicitation of immune responses against Chlamydia, and decreased levels of IL-10 correlated with protective anti-Chlamydia immunity. To investigate the molecular basis for these effects, we compared the reproductive pathologies and fertility rates in Chlamydia-infected wild-type (WT) and IL-10-knockout (IL-10−/−) mice; we also analyzed the expression of the Toll-like receptor (TLR)/interleukin-1 receptor (IL-1R) superfamily, IL-1β production, NLRP3 inflammasome assembly and activation, and the immunostimulatory capacity and apoptotic predilection of Chlamydia-exposed dendritic cells (DCs) from WT and IL-10−/− mice. Our results revealed that, in addition to the rapid clearance of infection, genitally infected IL-10−/− mice were protected from tubal pathologies and infertility, whereas WT (IL-10+/+) mice were not. Chlamydia-pulsed IL-10−/− DCs expressed larger numbers of TLR4/IL-1R molecules and had enhanced IL-1β production. In addition, NLRP3 inflammasome assembly was suppressed in IL-10−/− DCs through the inhibition of the P2X purinoceptor 7 (P2X7) receptor (P2X7R), an ATP-gated ion channel, and a decrease in intracellular Ca2+ levels, which inhibited DC apoptosis. Thus, the potent immunostimulatory capacity of IL-10-deficient DCs is due, at least in part, to the suppression of the intracellular inflammasome assembly, which prevents DC apoptosis, allowing efficient antigen presentation. The results indicate that IL-10 deficiency enables efficient antigen presentation by DCs for rapid and enhanced immune activation against Chlamydia, which results in rapid microbial clearance, which prevents tubal pathologies during infection. Our finding has important implications for the induction of protective immunity against Chlamydia and other infectious and noninfectious diseases by vaccines.

Fatal Ulcerative and Hemorrhagic Typhlocolitis in a Pregnant Heifer Associated with Natural Bovine Enterovirus Type-1 Infection

One 2-year-old, 7.5 months pregnant Aberdeen Angus out of a herd of 100 apparently healthy cows, died within 10 hours of hospitalization. At necropsy, multiple foci of mucosal hemorrhage and ulceration were observed in the spiral colon and cecum. Virus isolation from intestinal lesions yielded a cytopathic virus, which was revealed by electron microscopy to be an approximately 27 nm, nonenveloped virus. Further characterization by reverse transcription-polymerase chain reaction (RT-PCR), sequencing of the 5′UTR and partial VP1 coding region, and phylogenetic analysis classified the virus isolate as bovine enterovirus type 1 (BEV-1). No other significant pathogens were detected. This is the first report of BEV-1 isolated in the USA from an animal with fatal enteric disease in more than 20 years. Further investigation is required to determine the prevalence of BEV in North America and to establish the clinical relevance of this understudied virus.

Pathogenesis of a Bovine Enterovirus-1 Isolate in Experimentally Infected Calves

The pathogenesis and virulence of Bovine enterovirus-1 (BEV-1) in cattle is largely unknown. Reports concerning its virulence suggest that there might be an association between BEV-1 infections and a range of diseases in cattle that vary from respiratory to enteric to reproductive disease and infertility. In the current study, the pathogenesis associated with acute infection of BEV-1 in calves experimentally inoculated with the Oklahoma isolate of BEV-1 was described. Although interpretation of the study was limited by lack of an effective control group, results suggest that an association between inoculation of BEV-1, virus localization, and the potential development of lesions in the brain and heart probably exists. In the experiment, BEV-1 virus localized to the terminal ileum, ileocecal and cecocolonic junctions, spiral colon, and ileocecal lymph nodes; BEV-1 virus was detected in the cytoplasm of enterocytes, lamina propria macrophages, endothelium, neurons of the submucosal and myenteric plexi, and lymphocytes of the submucosal lymphoid tissue. Although no clinical signs were noted following acute infection, BEV-1 was localized in the cerebellar white matter of a calf with encephalitis and in the heart of another calf with coronary arteritis. The current study suggests that the BEV-1 isolate is infectious to young calves and that BEV-1 potentially can have a similar pathogenesis to that observed in natural or experimental enterovirus infections in other species.

Clinical relevance of novel Otarine herpesvirus-3 in California sea lions (Zalophus californianus): lymphoma, esophageal ulcers, and strandings

Herpesviruses have been recognized in marine mammals, but their clinical relevance is not always easy to assess. A novel otarine herpesvirus-3 (OtHV3) was detected in a geriatric California sea lion (Zalophus californianus), and using a newly developed quantitative PCR assay paired with histology, OtHV3 was associated with esophageal ulcers and B cell lymphoblastic lymphoma in this animal. The prevalence and quantities of OtHV3 were then determined among buffy coats from 87 stranded and managed collection sea lions. Stranded sea lions had a higher prevalence of OtHV3 compared to managed collection sea lions (34.9% versus 12.5%; p = 0.04), and among the stranded sea lions, yearlings were most likely to be positive. Future epidemiological studies comparing the presence and viral loads of OtHV3 among a larger population of California sea lions with and without lymphoid neoplasia or esophageal ulcers would help elucidate the relevance of OtHV3-associated pathologies to these groups.

Experimental Infection of C3H/HeJ Mice with the NY18 Isolate of Anaplasma phagocytophilum

Human granulocytic anaplasmosis (HGA), an emerging disease of public health concern in many areas of the world, is caused by Anaplasma phagocytophilum. Small animal models of A phagocytophilum in laboratory mice have been developed and used to study the pathogenesis of HGA. In this study, we characterized the pathologic changes in acute infection of C3H/HeJ mice experimentally infected with the NY18 isolate of A phagocytophilum. Although no clinical signs were noted, acute infection was associated with gross splenomegaly, microscopic inflammatory lesions in the lung and liver, hyperplastic lesions on the spleen, and clinical pathology abnormalities including neutropenia and monocytosis. This study emphasizes the use of well-defined animal models as a valuable tool for the study of A phagocytophilum infections.

Intrapericardial Ectopic Thyroid Carcinoma in a Cat

A 7-year-old spayed female domestic shorthair feline presented with tachycardia and was later euthanized due to a declining condition. On gross examination, the thoracic cavity contained an expansile, multiloculated mass that displaced the lungs dorsocaudally. The mass, within the pericardial sac, compressed adjacent myocardium. Cut surface revealed variably sized, fluid-filled spaces with multiple foci of hemorrhage and necrosis. Histologically, the mass was composed of solid foci of polygonal cells admixed with colloid-containing follicles. Immunohistochemical staining for thyroglobulin was positive, and staining for calcitonin was negative. Grossly, thyroid glands were normal, and serum thyroxine was within reference intervals.

Productive thyroid follicular carcinoma in a wild barred owl (Strix varia).

An adult male barred owl (Strix varia) was found unable to fly on a pasture during the day. On presentation, several lacerations were noted on the left wing. The animal was anesthetized for radiographic examination, which revealed mild swelling and irregularity of the soft tissues of the left wing. Over the plane of the syrinx and great vessels, ill-defined soft tissue opacity was present. The anesthetic recovery was unsuccessful, and the patient died. On gross necropsy, a 1 cm in diameter, round, soft, red-tan nodule, with scattered light tan to white foci was noticed between the right subclavian artery and the syrinx. The histopathology of this structure was characteristic of a thyroid follicular carcinoma. Neoplastic cells were immunoreactive to thyroglobulin and pancytokeratin proteins. A blood sample, taken antemortem, was analyzed for total and free thyroxine. Due to the lack of reference intervals for the current species, 4 blood samples from other barred owls were taken, 2 of which were clinically normal and 2 with an unhealthy status. The thyroid values were higher than the controls (total thyroxine by radioimmunoassay [µg/dl] 1.1 vs. <0.2, <0.2, 0.6, <0.2; free thyroxine by equilibrium dialysis [ng/dl] >10 vs. <0.3, <0.3, 2.1, <0.3). Although the other 4 birds are not intended to serve as a reference interval because of the low number and unhealthy status, findings are indicative of a productive thyroid follicular carcinoma.