A histological evaluation of pansteatitis-affected Mozambique tilapia, Oreochromis mossambicus (Peters 1852), from different geographical locations in South Africa.

Pansteatitis is the leading cause for the decline in Nile crocodile populations and the sporadic mortality of fish in the Olifants River System, South Africa. To determine the prevalence of this disease in lentic systems, Mozambique tilapia, Oreochromis mossambicus, were collected from Lake Loskop, Lake Flag Boshielo, Phalaborwa Barrage and Lake Luphephe-Nwanedi. The former three impoundments are located within the main stem of the Olifants River, while the latter, which is geographically isolated and situated in the Limpopo River System, served as a reference site. Mesenteric adipose, liver, serosa of the swim bladder, gill and the skeletal muscle of fish sampled were examined for gross and microscopic evidence of pansteatitis. Microscopically observed changes were used to statistically compare pansteatitis prevalence between samples and sites. Based on histopathological evaluation, the adipose tissue in the liver, swim bladder serosa and coelom from severely debilitated individuals showed the most significant pathological changes. Lesions indicative of steatitis were observed in fish collected from Lake Loskop (75%), Lake Flag Boshielo (22%) and Lake Luphephe-Nwanedi (15%). Further investigation is warranted to understand the pervasiveness and mechanisms driving pathological changes of pansteatitis at Lake Flag Boshielo, Phalaborwa Barrage and Lake Luphephe-Nwanedi.

Complex Virome in a Mesenteric Lymph Node from a Californian Sea Lion (Zalophus Californianus) with Polyserositis and Steatitis.

An emaciated subadult free-ranging California sea lion (Csl or Zalophus californianus) died following stranding with lesions similar to 11 other stranded animals characterized by chronic disseminated granulomatous inflammation with necrotizing steatitis and vasculitis, involving visceral adipose tissues in the thoracic and peritoneal cavities. Histologically, affected tissues had extensive accumulations of macrophages with perivascular lymphocytes, plasma cells, and fewer neutrophils. Using viral metagenomics on a mesenteric lymph node six mammalian viruses were identified consisting of novel parvovirus, polyomavirus, rotavirus, anellovirus, and previously described Csl adenovirus 1 and Csl bocavirus 4. The causal or contributory role of these viruses to the gross and histologic lesions of this sea lion remains to be determined.

Low Oleic/Stearic Desaturation Index in Great Blue Herons (Ardea herodias) with Steatitis in Southern California, USA.

We explored differences between the adipose tissue fatty acid profiles of Great Blue Herons (Ardea herodias) with and without steatitis. Adipose tissue from birds with steatitis exhibited inflammatory cell infiltration, low abundance of oleic acid, and a lower oleic/stearic desaturation index compared with tissue from birds without steatitis.

Pansteatitis in polluted Olifants River impoundments: nutritional perspectives on fish in a eutrophic lake, Lake Loskop, South Africa.

This study compares the aetiology of pansteatitis in Lake Loskop, relative to two other impoundments along the Olifants River. Macroscopic and microscopic pathology, age determination and analysis of stomach content, fatty acids and stable isotopes explain the high prevalence of pansteatitis in Oreochromis mossambicus (Peters) and several other species in Lake Loskop. All the dietary indicator comparisons between pansteatitis-affected and healthy fish fail to support a systemic cause. Pansteatitis in Lake Loskop was linked to size and weight of O. mossambicus, but not to ontogenic age. Fish in Lake Loskop showed abnormally high omega-3 to omega-6 fatty acid ratios normally only found in marine fish with no significant difference in degree of assimilation of these fatty acids between pansteatitis-affected and healthy fish. This explains the vulnerability to, but not the occurrence of, pansteatitis. As a cause for the pansteatitis, these results point towards sporadic vitamin E-depleting trigger events, known sporadic fish die-off occurrences that provide surviving fish with a rich source of rancid fats on which to scavenge. The mechanism ties pansteatitis to eutrophication and trophic cascade effects, the intrinsic drivers of the disease and suggests an adaptive management strategy that might be applied by relevant conservation authorities.

Histomorphology, ultrastructure and fatty acid composition of the adipose tissue in pansteatitis, the potentials in understanding the underlying mechanism and diagnosis of pansteatitis in the Nile crocodile.

BACKGROUND: In an effort to characterize the fat body and other adipose tissue in the Nile crocodile and the effects of pansteatitis on the structure and composition of the adipose tissue, we evaluated the regional variation in structure and fatty acid composition of healthy farmed crocodiles and those affected by pansteatitis. METHODS: Adipose tissue samples were collected from the subcutaneous, visceral and intramuscular fat and the abdominal fat body of ten 4-year old juvenile crocodiles from Izinthaba Crocodile Farm, Pretoria, South Africa while pansteatitis samples were collected from visceral and intramuscular fat of crocodiles that had died of pansteatitis at the Olifant River, Mpumalanga, also in South Africa. Histomorphology, ultrastrustucture and fatty acid composition by fatty acid methyl ester (FAME) analysis were conducted. RESULTS: Histological examination showed regional variations in the adipose tissue especially in the collagen content of the ECM, tissue perfusion and division into lobes and lobules by fibrous capsule. Considerable fibrosis, mononuclear cell infiltration especially by macrophages and lymphocytes and toxic changes in the nucleus were observed in the pansteatitis samples. Regional variation in lipid composition especially in Myristoleic (C14:1), Erucic acid (C22:1n9), and Docosadienoic acid (C22:2n6) was observed. Most of the saturated and trans fatty acids were found in significant quantities in the pansteatitis samples, but had very low levels of the cis fatty acid and the essential fatty acids with C18 backbone. CONCLUSION: This study demonstrates that there exists some regional variation in histomorphology and fatty acid composition in the healthy adipose tissue of the Nile crocodile. It also showed that pansteatitis in the Nile crocodile might have been triggered by sudden change in energy balance from consumption of dead fish; and probable exposure to toxic environmental conditions with the evidence of up scaled monounsaturated long chain fatty acids composition and toxic changes in the leucocytes observed in pansteatitis in the present study.

Prostatitis, steatitis, and diarrhea in a dog following presumptive flea-borne transmission of Bartonella henselae.

Bartonella henselae is increasingly associated with a variety of pathological entities, which are often similar in dogs and human patients. Following an acute flea infestation, a dog developed an unusual clinical presentation for canine bartonellosis. Comprehensive medical, microbiological, and surgical interventions were required for diagnosis and to achieve a full recovery.

Pansteatitis associated with high levels of polychlorinated biphenyls in a wild loggerhead sea turtle Caretta caretta.

We describe the morphologic and toxicological findings in a case of pansteatitis in a stranded loggerhead sea turtle Caretta caretta. At necropsy, a large amount of adipose tissue in the celomic cavity showing very firm, yellow to orange irregular formations was observed. Histological lesions ranged from the infiltration of necrotic fat by scarce multinucleated giant cells and numerous macrophages containing xylene-insoluble lipopigment inclusions to the presence of several granulomas characterized by an irregular central necrotic area consisting of lipopigment surrounded by numerous multinucleated giant cells. Microbiological cultures were negative. Celomic fat was analyzed for PCBs and DDTs, resulting in very high levels of PCB 138, 153, 180 209 (3170, 2830, 980 and 1190 ng g-1, respectively). Although a nutritional cause cannot be ruled out, the high levels of PCBs detected in the celomic fat could have induced lipid peroxidation in adipocytes, resulting in cell damage, deposition of ceroid pigment and inflammatory response. This is the first report of pansteatitis in a wild sea turtle.

Prevalence of pansteatitis in African sharptooth catfish, Clarias gariepinus (Burchell), in the Kruger National Park, South Africa.

Pansteatitis was confirmed in sharptooth catfish, Clarias gariepinus (Burchell), from three main locations within the Kruger National Park (KNP); the Olifants River Gorge, Engelhard Dam on the Letaba River and from the Sabie River in the Sabiepoort. An increasing prevalence of pansteatitis was observed in catfish during repeated samplings from the Olifants Gorge from 2009 to 2011 and co-existence of old and recent lesions indicated on-going incitement of pansteatitis. Only a low prevalence of pansteatitis was observed in catfish sampled from the Olifants River upstream of the Gorge in the KNP and no pansteatitis was observed in catfish sampled from a rain-filled dam not connected to the Olifants River. Common to both the Olifants Gorge and the Sabiepoort is the damming of the rivers in Mozambique to form lakes Massingir and Corumana respectively. Anthropogenic activities resulting in potential pollution of the rivers differ greatly between these two catchments, providing argument against a primary pollution-related aetiology of the pansteatitis found at these two sites. Compared with other sites, analysis of stomach contents of catfish from the Olifants Gorge and the Sabiepoort strongly suggested that consumption of a predominantly fish diet was associated with the development of pansteatitis in these fish. In a farmed population of catfish used as positive control, development of pansteatitis could be ascribed to consumption of rancid fish waste from a trout slaughterhouse. In the Olifants Gorge, alien invasive silver carp, Hypophthalmychthys molitrix (Valenciennes), seasonally migrate upstream out of Lake Massingir to spawn. This schooling species is an obligate phytoplankton feeder with consequent high levels of adipose tissue n-3 polyunsaturated fatty acids. In the Olifants Gorge, at least, this may explain seasonal exposure to levels of polyunsaturated fats in the diets of catfish and crocodiles to which these animals are not adapted. The possible roles of diet, membrane lipid composition and metabolic rate of fish, sediment pollution and seasonal drop in environmental temperature in the pathogenesis of pansteatitis in the catfish are discussed. Further studies are needed to verify some of these speculations.

Steatitis in wild sharptooth catfish, Clarias gariepinus (Burchell), in the Olifants and lower Letaba Rivers in the Kruger National Park, South Africa.

Large numbers of adult Nile crocodiles, Crocodylus niloticus (Laurenti), died from pansteatitis during autumn and winter 2008 in the lower Letaba and Olifants River gorge in the Kruger National Park, South Africa. Consequently, the health status of fish from these waters was investigated. The study presents the pathological findings in fish inhabiting these rivers within the boundaries of the Park. Changes typical of steatitis were diagnosed in many of the larger specimens of sharptooth catfish, Clarias gariepinus (Burchell), caught within the Olifants River gorge. These fish carried large amounts of mesenteric fat with characteristic small brown granulomata within the adipose tissue. Necrosis and inflammation of the adipose tissues, with characteristic ceroid accumulation within the resultant granulomata and the associated aggregation of ceroid-containing macrophages, were demonstrated histologically and were typical of steatitis. Other changes included mild thickening and pallor of the gill tissues and swollen, orange, fatty livers. Focal hepatic lipidosis was demonstrated histologically, and special stains revealed storage of large amounts of iron in the livers. Blood smears revealed chromatin clumping in erythrocyte nuclei and nuclear and cell membrane irregularities. This is the first record of steatitis in wild-caught C. gariepinus.

Comparison of the lipid properties of captive, healthy wild, and pansteatitis-affected wild Nile crocodiles (Crocodylus niloticus).

The results presented describe and compare the fatty acid composition and melting properties of captive, healthy wild, and pansteatitis-affected wild crocodiles (Crocodylus niloticus). Differences in fatty acid composition between intramuscular and adipose fat is noted in captive crocodiles, and the latter differs from wild crocodiles as a result of different diets. Adipose fat of healthy wild crocodiles differs minimally from diseased ones, respectively with 37.3+/-2.6% vs. 43.2+/-2.3% monounsaturated fatty acids, and 43.2+/-2.9% in dead crocodiles, while polyunsaturated fatty acids decrease from 27.3+/-1.9% to as low as 21.9+/-3.6% respectively. Of the unsaturated fatty acids 18:2n-6 decreased from 6.5+/-2.6% in unaffected crocodiles to 3.5+/-0.6% in highly affected and 3.2+/-0.4% in dead crocodiles, and 22:5n-3 from 2.8+/-0.6% to 1.8+/-0.3% and 2.2+/-0.3% respectively. The melting properties as determined by differential scanning calorimetry show that extracted adipose fat is a small degree softer in pansteatitis-affected tissue, specifically in the temperature range 7-36 degrees C, and does not contribute to the hard texture noted for adipose fat tissue of pansteatitis-affected animals. A high moisture content of 51.0+/-19.7% of the fat tissue of pansteatitis-affected animals vs.17.1+/-8.0% of healthy ones, suggests that physiological changes due to interstitial inflammation may contribute to the hard texture.

Lactic acid bacteria prevent alcohol-induced steatohepatitis in rats by acting on the pathways of alcohol metabolism.

The objective is to study the possible mechanism by which lactic acid bacteria (LAB) prevent alcohol-induced steatohepatitis in rats. A total of 25 Wistar rats were divided into three groups: a LAB-fed group, an alcohol-treated group and a control group. Both the LAB-fed group and the alcohol-treated group received alcohol (10 g kg(-1) per day) orally for up to 5 days (125 h). Before exposure to alcohol, the LAB-fed group were first treated daily with 1.5 ml/100 g of a mixture comprising 4 x 10(10) ml(-1) of Lactobacillus acidophilus and 2.5 x 10(7) ml(-1) of Bifidobacterium longum, while the control group was treated with normal saline only. Biochemical data, alcohol dehydrogenase (ADH) activity and histology of the liver and stomach were evaluated. The ADH activity in the LAB mixture was 3.52 +/- 0.45 mumol mg(-1) protein (10(9) CFU ml(-1)), and was dose-dependent. By 30 min after taking alcohol, serum alcohol concentrations were 514.24 +/- 80.21 microg ml(-1) in the LAB-fed group and 795.15 +/- 203.45 microg ml(-1) in the alcohol-treated group (P < 0.005). Serum alcohol concentrations were reduced by 48% (P < 0.01) in the LAB-fed group, but by only 4% in the alcohol-treated group (P > 0.05) 120 min after oral intake of alcohol. The blood levels of endotoxin, AST and ALT were improved in the LAB-fed group compared to the alcohol-fed group (P < 0.01). All alcohol-treated rats showed moderate to severe steatohepatitis, but the LAB-fed rats showed almost normal histology or very slight lesions only. In conclusion, LAB decreased the alcohol concentration in the blood by increasing the first-pass metabolism in both the stomach and the liver, and effectively protected against alcohol-induced gastric and liver injury. It is interesting to note that the protection was more effective in the liver.

The proinflammatory phenotype of PECAM-1-deficient mice results in atherogenic diet-induced steatohepatitis.

The severity of nonalcoholic steatohepatitis (NASH) is determined by environmental and genetic factors, the latter of which are incompletely characterized. Platelet endothelial cell adhesion molecule-1 (PECAM-1) is a 130-kDa transmembrane glycoprotein expressed on blood and vascular cells. In the present study, we provide data for the novel finding that genetic deficiency of PECAM-1 potentiates the development and progression of NASH. We found that the rate of development and severity of diet-induced NASH are markedly enhanced in PECAM-1-deficient [knockout (KO)] mice relative to wild-type (WT) mice, as measured by histological and biochemical evaluation. Livers from KO mice exhibited typical histological features of NASH, including macrovesicular fat accumulation, hepatocyte injury with infiltration of inflammatory cells, fibrosis, and heightened oxidative stress. Alanine aminotransferase, a marker for liver injury, was also significantly higher in KO compared with WT mice. Consistent with a role for PECAM-1 as a suppressor of proinflammatory cytokines, plasma levels of inflammatory cytokines, including TNF-alpha and monocyte chemoattractant protein-1 (MCP-1), were also significantly higher in KO compared with WT mice. These findings are the first to show that the PECAM-1-deficient mouse develops progressive nonalcoholic fatty liver disease (NAFLD), supporting a role for PECAM-1 as a negative regulator of NAFLD progression. Future examination of recently identified PECAM-1 allelic isoforms in humans as potential risk factors for developing NASH may be warranted.

Pansteatitis and severe hypocalcaemia in a cat.

A 13-year-old Siamese cat was presented for investigation of lethargy and progressive abdominal enlargement. Serum chemistry revealed severe reduction of total and ionised serum calcium. The omentum appeared hyperechoic with scattered hypoechoic foci on abdominal ultrasound examination. Elevated serum parathormone and low fractional excretion of calcium excluded a parathyroid disorder and renal loss of the electrolyte. During laparotomy the omentum appeared opaque, white and firm. Post-mortem examination revealed that the thoracic and subcutaneous fat was also affected. Histopathology confirmed the diagnosis of pansteatitis with diffuse calcium soaps formation. While, severe hypocalcaemia is occasionally seen in cats, the association with pansteatitis has not been reported previously. In man, a cause-and-effect relationship between calcium soaps and hypocalcaemia is recognised, though the association is rare.

Feline cutaneous and visceral necrotizing panniculitis and steatitis associated with a pancreatic tumour.

The association of pancreatic disorders with fat necrosis in domestic animals is rare. This report concerns a case of cutaneous/subcutaneous necrotizing panniculitis and steatitis associated with a pancreatic adenocarcinoma in an 11-year-old male Siamese cat. Clinical investigation revealed variably sized nodules on the trunk, limbs and abdomen. Some of them were ulcerated; others showed a shiny yellow necrotic background featuring irregular sinus tracts. The cat was euthanized at the owner's request before a diagnosis could be made. At necropsy, abundant oily material resembling mustard replaced the subcutaneous tissue and small yellow nodules were disseminated in the omentum, mesentery and serosa of the abdomen. A multilobulated mass arising from the anterior pancreatic head was found along with liver and lymph node metastasis. Histopathology showed wide fistulous tracts draining necrotic fat from the subcutis toward the surface and multifocal areas of necrotic adipocytes replacing the panniculus. Duct-like structures and tubules lined by neoplastic epithelial cells were observed in the primary pancreatic tumour and in the metastatic sites. The aetiology of the fat necrosis was possibly the result of systemic release of lipolytic pancreatic enzymes.

Anemia, myopathy, and pansteatitis in vitamin E-deficient captive marmosets (Callithrix spp.).

Five young adult pet marmosets (Callithrix spp.) were presented with weight loss (5/5); fecal retention (3/5); diarrhea (2/5); impaired locomotion (3/5); anemia (4/4); hypoproteinemia or hypoalbuminemia (3/4); elevations of creatine phosphokinase, lactic dehydrogenase, and alanine aminotransferase (3/4); and renal failure with hypercholesterolemia (2/4). All anemic marmosets had low serum vitamin E levels. The anemia responded to vitamin E and selenium therapy in two marmosets. One of the five marmosets died before presentation, and two others died despite therapy. The two marmosets necropsied had degenerative myopathy, pyogranulomatous pansteatitis, and increased erythrophagocytosis and hemosiderosis. The striated muscle and adipose tissue of both marmosets were negative for coxsackievirus ribonucleic acid by in situ hybridization. These findings suggest that vitamin E deficiency may be involved in the development of anemia, myopathy, and steatitis in callitrichids; however, in some marmosets, underlying diseases such as chronic colitis may have influenced the development of anemia and impaired vitamin E status.

Idiopathic mesenteric and omental steatitis in a dog.

A 2-year-old Miniature Dachshund was admitted to the hospital because of fever, frequent vomiting, and watery diarrhea. An intra-abdominal mass and a gastric ulcer were detected. At laparotomy, the omentum was yellow but not icteric, irregularly thickened, and fragile, and a large mass involving the root of the mesentery and the gastrosplenic ligament was found. The histopathologic diagnosis was steatitis, and the dog was treated with prednisolone and cyclosporine for 2.5 years. After 1.5 years, the abdominal mass was not detectable. The dog died suddenly from perforation of the small intestine caused by a foreign body. Necropsy revealed severe adhesions between portions of the small intestine, and cicatrization of the mesentery. Cause of the mesenteric and omental steatitis was not apparent.

The histopathology and ultrastructure of steatitis affecting common dab Limanda limanda.

This study presents a new description, based on histopathological and ultrastructural studies, of a disease affecting the common dab Limanda limanda (L.). The condition can be recognised by the presence of multiple orange or yellow lesions in the pterygophorial region of the fish. The principal histopathological features are necrosis of fat cells, extensive macrophage infiltration leading to the formation of granulomatous structures, and the accumulation of lipopigment by lipid peroxidation. Based on this description, the condition has been diagnosed as steatitis. Although pathology associated with lipid peroxidation is the dominant characteristic of the lesions examined, it is proposed that this process is secondary to necrosis of the adipose tissue. The aetiology is discussed in the light of these observations. In addition, the first record of this condition affecting long rough dab Hippoglossoides platessoides (Fabricius) is made.