Inflammatory Mediators in the Mesenteric Lymph Nodes, Site of a Possible Intermediate Phase in the Immune Response to Feline Coronavirus and the Pathogenesis of Feline Infectious Peritonitis?

Feline infectious peritonitis (FIP) is an almost invariably fatal feline coronavirus (FCoV)-induced disease thought to arise from a combination of viral mutations and an overexuberant immune response. Natural initial enteric FCoV infection may remain subclinical, or result in mild enteric signs or the development of FIP; cats may also carry the virus systemically with no adverse effect. This study screened mesenteric lymph nodes (MLNs), the presumed first site of FCoV spread from the intestine regardless of viraemia, for changes in the transcription of a panel of innate immune response mediators in response to systemic FCoV infection and with FIP, aiming to identify key pathways triggered by FCoV. Cats with and without FIP, the latter with and without FCoV infection in the MLN, were compared. Higher expression levels in FIP were found for toll-like receptors (TLRs) 2, 4 and 8. These are part of the first line of defence and suggest a response to both viral structural proteins and viral nucleic acid. Expression of genes encoding inflammatory cytokines and chemokines, including interleukin (IL)-1ß, IL-6, IL-15, tumour necrosis factor (TNF)-α, CXCL10, CCL8, interferon (IFN)-α, IFN-ß and IFN-γ, was higher in cats with FIP, consistent with inflammatory pathway activation. Expression of genes encoding transcription factors STAT1 and 2, regulating signalling pathways, particularly of the interferons, was also higher. Among cats without FIP, there were few differences between virus-positive and virus-negative MLNs; however, TLR9 and STAT2 expression were higher with infection, suggesting a direct viral effect. The study provides evidence for TLR involvement in the response to FCoV. This could open up new avenues for therapeutic approaches.

Ultrasonographic findings in two sheep with enzootic calcinosis.

INTRODUCTION: This report describes 2 sheep with enzootic calcinosis characterized by abnormal cardiovascular and respiratory findings and ascites causing abdominal distension. Both sheep were anorexic and listless and had increased heart and respiratory rates. Auscultation of the heart revealed a gallop rhythm in sheep 1 and a loud systolic heart murmur in sheep 2. The activities of liver enzymes were severely increased in both sheep. Abdominal ultrasonography showed severe ascites and congestion of the liver and caudal vena cava. Echocardiography in sheep 2 showed hyperechoic and markedly thickened mitral and aortic valves with moderate-severe mitral insufficiency and generalized cardiomegaly. Both sheep were euthanized and examined postmortem. In addition to ascites and pleural effusion, the principal lesions were nodular thickening of the heart valves and calcification of the aorta and other arteries. Nutrition of the sheep did not include hay pellets, but the sheep were kept together with alpacas and lamas and had access to the hay pellets of these animals. In addition visitors were allowed to feed the sheep with hay pellets offered by the zoo in a dispenser. The two types of hay pellets had Vit D concentrations of 9'900 IU VitD3/kg and 7'000 IU Vit D2/kg, respectively. The definitive diagnosis was enzootic calcinosis.

Intrapulmonary arteriovenous anastomoses in dogs with severe Angiostrongylus vasorum infection: clinical, radiographic, and echocardiographic evaluation.

BACKGROUND: In both humans and dogs the pulmonary vasculature is able to recruit large-diameter anatomical intrapulmonary arteriovenous anastomoses (IPAVAs). In healthy people the opening of these anastomoses affects the degree of exercise-induced increase in pulmonary arterial pressure. The presence of these IPAVAs can be demonstrated using saline contrast echocardiography. OBJECTIVES: The aims of the present study were to characterize severely affected, naturally infected dogs with Angiostrongylus vasorum, to evaluate if these dogs can open IPAVAs, and to assess if the recruitment of such anastomoses affects the severity of pulmonary hypertension (PH). ANIMALS: Eight client-owned dogs with severe A. vasorum infection were recruited. METHODS: Dogs with A. vasorum infection that presented with severe dyspnea and/or syncope were prospectively screened by echocardiography for the presence of PH and IPAVAs. Only severely affected dogs, based on a combination of clinical, radiographic and echocardiographic abnormalities, were enrolled. RESULTS: Opening of IPAVAs could be demonstrated in three dogs with no to moderate PH, and could not be demonstrated in five dogs with severe PH. In two dogs thoracic radiographs showed only mild interstitial changes, while computer tomography and postmortem examination revealed severe pulmonary interstitial and vascular disease. CONCLUSIONS: These results suggest that dogs may open IPAVAs and that opening of such anastomoses may play a regulatory role in the development of PH. There may be a marked discrepancy between radiographic changes and disease severity in A. vasorum.

Alveolar macrophages are the main target cells in feline calicivirus-associated pneumonia.

Feline calicivirus (FCV) is a pathogen of felids and one of the most common causative agents of feline upper respiratory disease (URD). Reports of natural FCV pneumonia in the course of respiratory tract infections are sparse. Therefore, knowledge on the pathogenesis of FCV-induced lung lesions comes only from experimental studies. The aim of the present study was to assess the type and extent of pulmonary involvement in natural respiratory FCV infections of domestic cats and to identify the viral target cells in the lung. For this purpose, histology, immunohistochemistry and RNA-in situ hybridisation for FCV and relevant cell markers were performed on diagnostic post-mortem specimens collected after fatal URD, virulent systemic FCV or other conditions. All groups of cats exhibited similar acute pathological changes, dominated by multifocal desquamation of activated alveolar macrophages (AM) and occasional type II pneumocytes with fibrin exudation, consistent with diffuse alveolar damage (DAD). In fatal cases, this was generally seen without evidence of epithelial regeneration. In cats without clinical respiratory signs, type II pneumocyte hyperplasia was present alongside the other changes, consistent with the post-damage proliferative phase of DAD. FCV infected and replicated in AM and, to a lesser extent, type II pneumocytes. This study shows that lung involvement is an infrequent but important feature of FCV-induced URD. AM are the main viral target cell and pulmonary replication site, and their infection is associated with desquamation and activation, as well as death via apoptosis.

Characterisation of the inflammatory reaction in equine idiopathic focal eosinophilic enteritis and diffuse eosinophilic enteritis.

REASONS FOR PERFORMING STUDY: Idiopathic focal eosinophilic enteritis (IFEE) and diffuse eosinophilic enteritis (DEE) are primary eosinophilic intestinal conditions without a known cause that are associated with an increasing number of surgical colic cases. Histology may be helpful in defining disease aetiology and pathogenesis. OBJECTIVES: To characterise further the inflammatory infiltrate in equine IFEE and to compare the condition with DEE. METHODS: Twenty-three IFEE cases and 5 DEE cases were examined by light microscopy including immunohistology to identify infiltrating leucocytes. Inflammatory infiltrates in mucosa and submucosa were characterised in IFEE lesions (Group 1), the intestine distant from the lesions in IFEE (Group 2) and DEE (Group 3). RESULTS AND CONCLUSIONS: IFEE lesions represented an accumulation of leucocytes in submucosa and muscularis, with dominance of eosinophils and macrophages and smaller numbers of lymphocytes, plasma cells and neutrophils. T cells represented the dominant lymphocytes. The mucosa overlying the lesion and both mucosa and submucosa in IFEE nonlesion sites and in DEE exhibited a similar composition, with different prevalence of various cell types. Macrophages were significantly more prevalent in the mucosal and submucosal infiltrates in IFEE nonlesion sites than in DEE, and lymphocytes significantly more prevalent in the mucosa in DEE than in IFEE nonlesion sites. The findings confirm IFEE as a primary eosinophilic intestinal disorder and indicate that IFEE represents a focally exacerbated inflammatory reaction in horses with DEE, possibly due to functional changes in the macrophage and T cell components, with subsequent excessive recruitment of both eosinophils and macrophages.

Toward a prospective payment system for ambulatory surgery.

In this article, ambulatory surgery among the aged Medicare population in 1985 is examined. Total hospital facility charges for ambulatory surgery in that year were estimated at $1.8 billion, with about one-half of that amount involving cataract surgery. The possibility of using diagnosis-related groups for a prospective payment system for ambulatory surgery was examined and was rejected for two reasons: (1) about 20 percent of the dollar volume of hospital-based ambulatory surgery fell into medical diagnosis-related groups and (2) the ratio of inpatient diagnosis-related group weight to outpatient billed charges for the ambulatory procedures falling into a given diagnosis-related group varied more than tenfold, making diagnosis-related group weights impossible to use in a consistent manner. A newly developed version of ambulatory visit groups and the even newer ambulatory patient groups were then considered as an alternative for a prospective payment system. These are briefly described.

Case mix and charges for inpatient and outpatient chemotherapy.

Case mix and charges for chemotherapy treatment were examined by an analysis of the inpatient discharges for DRG 410 (chemotherapy) from eight teaching hospitals and of outpatient visits from two teaching hospitals. Discharges for ovarian cancer were the most common and the least expensive, costing $1,600 or half as much as the most costly, less common conditions (leukemia and testicle cancer). Diagnosis explained 13 percent of the inpatient charge variation; metastasis explained less than 1 percent. Outpatient chemotherapy overlapped with inpatient among only 3 of the 10 most common diagnoses. The implication is that the two settings are complementary with regard to chemotherapy administration.

A comparison of hospital outpatient departments and private practice.

This article addresses cost differences between primary care physicians in private practice and hospital outpatient departments (OPD's). The analysis utilizes ambulatory visit groups (AVG's), the outpatient equivalent of diagnosis-related groups (DRG's), to adjust for case mix. Major findings are that OPD's have higher per visit costs than physicians' private offices; internists are more expensive than general practitioners regardless of site; and ancillary service costs are actually slightly higher in private practice. Any prospective payment system for ambulatory care must consider these costs differences.