Sox9, Hopx, and survivin and tuft cell marker DCLK1 expression in normal canine intestine and in intestinal adenoma and adenocarcinoma

Self-renewal of the intestinal epithelium originates from stem cells located at the crypt base. Upregulation of various stem cell markers in intestinal epithelial neoplasms indicates a potential role of stem cells in tumorigenesis. In this study, the immunoreactivity of potential intestinal stem cell markers ( Sry box transcription factor 9 [Sox9], homeodomain-only protein [Hopx], survivin) and tuft cell marker doublecortin-like kinase 1 (DCLK1) in normal canine intestine and intestinal epithelial neoplasms was investigated. Formalin-fixed paraffin-embedded (FFPE) small and large intestine as well as intestinal neoplasms (55 colorectal adenomas [CRAs], 17 small intestinal adenocarcinomas [SICs], and 12 colorectal adenocarcinomas [CRCs]) were analyzed immunohistologically. Potential stem cell markers Sox9, Hopx, and survivin were detected in the crypts of normal canine small and large intestine. DCLK1+ tuft cells were present in decreasing numbers along the crypt-villus axis of the jejunum and rarely detectable in large intestine. In canine intestinal epithelial tumors, nuclear Sox9 immunoreactivity was detectable in 84.9% (CRA), 80% (CRC), and 77% of epithelial neoplastic cells (SIC). Hopx and survivin were expressed within cytoplasm and nuclei of neoplastic cells in benign and malignant tumors. DCLK1 showed a cytoplasmic reaction within neoplastic cells. The combined score of Hopx, DCLK1, and survivin varied among the examined cases. Overall, malignant tumors showed lower DCLK1 scores but higher Hopx scores in comparison with benign tumors. For survivin, no differences were detectable. In conclusion, stem cell markers Sox9, Hopx, and survivin were detectable at the crypt base and the immunoreactivity of Sox9, DCLK1, survivin, and Hopx was increased in canine intestinal adenomas and adenocarcinomas compared with normal mucosa.

Meningoencephalomyelitis of Unknown Origin in Cats: A Case Series Describing Clinical and Pathological Findings

Meningoencephalomyelitis of unknown origin (MUO) is an umbrella term describing inflammatory changes of the central nervous system (CNS) with suspected non-infectious etiology. Diagnosis of MUO mostly remains presumed in a clinical setting. Histopathological and immunohistochemical examination of CNS tissue represent additional tools for detection of inflammation and the exclusion of specific infectious agents. While MUO is well-described in canine patients, only little is known about MUO in cats. Previous reports of feline MUO involve either clinical findings or histopathological examination but not both. The present case series is the first report describing both clinical and histopathological findings of feline MUO: Four cats (age: 1.7–17.8 years) showed acute to chronic progressive neurological signs of encephalopathy or myelopathy. Three cats had extraneural signs (hyperthermia, weight loss, hyporexia, leukocytosis). Magnetic resonance imaging (MRI) showed multifocal intraparenchymal lesions in forebrain, brainstem or spinal cord with homogenous contrast enhancement (2/2). Cerebrospinal fluid (CSF) examination was normal or displayed albuminocytologic dissociation. Histopathology revealed a multifocal, lympho-histiocytic meningoencephalitis in three cases and a lympho-histiocytic myelitis in one case. Immunohistochemistry for feline parvovirus, feline coronavirus, feline herpesvirus, tick borne encephalitis virus, Borna disease virus, morbillivirus, rabies virus, suid herpesvirus-1, and Toxoplasma gondii were negative in all cases.

Characterization of six canine prostate adenocarcinoma and three transitional cell carcinoma cell lines derived from primary tumor tissues as well as metastasis

Canine prostate adenocarcinoma (PAC) and transitional cell carcinoma (TCC) of prostate and urinary bladder are highly invasive and metastatic tumors of closely neighbored organs. Cell lines are valuable tools to investigate tumor mechanisms and therapeutic approaches in vitro. PAC in dogs is infrequent, difficult to differentiate from TCC and usually characterized by poor prognosis, enhancing the value of the few available cell lines. However, as cell lines adapt to culturing conditions, a thorough characterization, ideally compared to original tissue, is indispensable. Herein, six canine PAC cell lines and three TCC cell lines were profiled by immunophenotype in comparison to respective original tumor tissues. Three of the six PAC cell lines were derived from primary tumor and metastases of the same patient. Further, two of the three TCC cell lines were derived from TCCs invading into or originating from the prostate. Cell biologic parameters as doubling times and chemoresistances to commonly used drugs in cancer treatment (doxorubicin, carboplatin and meloxicam) were assessed. All cell lines were immunohistochemically close to the respective original tissue. Compared to primary tumor cell lines, metastasis-derived cell lines were more chemoresistant to doxorubicin, but equally susceptive to carboplatin treatment. Two cell lines were multiresistant. COX-2 enzyme activity was demonstrated in all cell lines. However, meloxicam inhibited prostaglandin E2 production in only seven of nine cell lines and did neither influence metabolic activity, nor proliferation. The characterized nine cell lines represent excellent tools to investigate PAC as well as TCC in prostate and urinary bladder of the dog. Furthermore, the profiled paired cell lines from PAC primary tumor and metastasis provide the unique opportunity to investigate metastasis-associated changes PAC cells undergo in tumor progression. The combination of nine differently chemoresistant PAC and TCC cell lines resembles the heterogeneity of canine lower urinary tract cancer.

Analysis of Copy-Number Variations and Feline Mammary Carcinoma Survival

Feline mammary carcinomas (FMCs) are highly malignant. As the disease-free survival (DFS) and overall survival (OS) are short, prognostication is crucial. Copy-number variations (CNVs) analysis by next-generation sequencing serves to identify critical cancer-related genomic regions. Thirty-three female cats with FMCs were followed during two years after surgery. Tumours represented tubulopapillary and solid carcinomas encompassing six molecular subtypes. Regardless of the histopathological diagnosis, molecular subtypes showed important differences in survival. Luminal A tumours exhibited the highest DFS (p = 0.002) and cancer-specific OS (p = 0.001), and the lowest amount of CNVs (p = 0.0001). In contrast, basal-like triple-negative FMCs had the worst outcome (DFS, p < 0.0001; and OS, p < 0.00001) and were the most aberrant (p = 0.05). In the multivariate analysis, copy-number losses (CNLs) in chromosome B1 (1-23 Mb) harbouring several tumour-repressors (e.g. CSMD1, MTUS1, MSR1, DBC2, and TUSC3) negatively influenced DFS. Whereas, copy-number gains (CNGs) in B4 (1-29 Mb) and F2 (64-82.3 Mb) comprising epithelial to mesenchymal transition genes and metastasis-promoting transcription factors (e.g. GATA3, VIM, ZEB1, and MYC) negatively influenced DFS and cancer-specific OS. These data evidence an association between specific CNVs in chromosomes B1, B4 and F2, and poor prognosis in FMCs.

Claudin-1, -3, -4 and -7 gene expression analyses in canine prostate carcinoma and mammary tissue derived cell lines

Claudins (CLDNs) are transmembrane proteins localised in the cell membrane of epithelial cells composing a structural and functional component of the tight junction protein complexes. In canine tumors deregulations of the CLDN expression patterns were described immunohistochemically. Targeting of claudin proteins has further been evaluated to establish novel therapeutic approaches by directed claudin binding. Precondition for the development of claudin targeting approaches in canine cells is the possibility to characterise claudin expression specifically and the availability of claudin positive cell lines. Herein PCR/qPCR assays were established allowing a rapid qualitative and quantitative characterisation of CLDN-1, -3, -4 and -7 gene expression in canine cell lines and tissues. Further commercially available antibodies were used to verify CLDN gene expression on protein level by Western blots. The developed assays were used to analyse six canine cell lines derived from mammary and prostate tissue for their CLDN-1, -3, -4 and -7 expressions. The canine cell line DT08/40 (prostate transitional cell carcinoma) was used for the establishment of specific CLDNs -1, -3, -4 and -7PCR/qPCR. The designed assays were verified by amplicon cloning and sequencing. Gene expressions were verified on protein level by Western blot. Additionally further cell lines were analysed for their CLDN-1, -3, -4 and -7 expression on mRNA and protein level (mammary derived cell lines: MTH53A (non-neoplastic), ZMTH3 (adenoma), MTH52C (carcinoma); prostate derived cell lines: DT08/46 and CT1258 (both adenocarcinoma).The screened cell lines showed expression for the CLDNs as follows: DT08/46 and DT08/40: CLDN-1, -3, -4 and -7 positive; CT1258: CLDN-1, -3, -4 and -7 negative; ZMTH3 and MTH52C: CLDN-1 and -7 positive, CLDN-3 and -4 negative; MTH53A: CLDN-1, -3 and -4 negative, CLDN-7 positive. Western blot analyses reflect the detected CLDN-1, -3, -4 and -7 expressions in the analysed cell lines. The established CLDN-1, -3, -4 and -7 PCR/qPCR assays allow a qualitative and quantitative characterisation of canine CLDN gene expression. Characterisation of CLDN expression in six canine cell lines led to the identification of two canine prostate tissue derived CLDN expressing cell lines. These cell lines serve as candidates for further research on CLDN-based functional and therapeutic approaches.

Plexiform Vasculopathy in Feline Cervical Lymph Nodes

Plexiform vasculopathy refers to an endothelial proliferative disorder affecting cervical or inguinal lymph nodes of cats. The cause of this disorder and the origin of the proliferating endothelial cells are still unknown. In 4 cats with a history of a slowly growing, well-demarcated, nonpainful mass adjacent to the thyroid gland, an enlarged dark brown to red lymph node was removed. Histologically, the lymph nodes showed severe loss of lymphoid tissue with accumulations of erythrocytes. In addition, networks of capillary structures with well-differentiated endothelial cells on a collagen-rich stroma were observed, consistent with benign plexiform vasculopathy. Immunohistochemistry revealed the expression of the vascular endothelial markers CD31 and factor VIII-related antigen. In addition, immunolabeling with a Prox-1 antibody indicated a lymphendothelial origin. With respect to our findings, a lymphendothelial origin has to be considered in cases of intranodal vascular neoplasms.

Effects of a Grapevine Shoot Extract Containing Resveratrol and Resveratrol Oligomers on Intestinal Adenoma Development in Mice: In Vitro and In Vivo Studies

SCOPE

Evidence suggests that the dietary consumption of plant extracts containing polyphenols might help prevent the onset of cancers of the gastrointestinal tract. In the present study, the chemopreventive and antiproliferative efficacy of a grapevine shoot extract (Vineatrol®30) containing resveratrol and resveratrol oligomers is investigated in vivo and in vitro.

METHODS AND RESULTS

The in vivo study is performed using Apc^Min mice on a high-fat diet, which represents a model of human adenomatous polyposis, while the potential of the extract as well as some of its isolated constituents to inhibit intestinal adenoma cell proliferation in vitro is investigated using APC10.1 cells derived from an Apc^Min mouse. Vineatrol®30 at a low (2.3 mg kg^-1  diet) or high dose (476 mg kg^-1  diet) reduces the adenoma number in male and adenoma volume in female animals. Furthermore, Vineatrol®30 as well as resveratrol and two resveratrol tetramers compromise the expansion of APC10.1 cells by reducing cell number, inducing cell cycle arrest, cellular senescence, and apoptosis. However, except for the extract, none of the isolated resveratrol oligomers is more efficacious than resveratrol in these cells.

CONCLUSION

Vineatrol®30 may merit further investigation as a potential dietary gastrointestinal cancer chemopreventive agent in humans.

Zoonotic intestinal helminths interact with the canine immune system by modulating T cell responses and preventing dendritic cell maturation

Parasite co-evolution alongside the mammalian immune system gave rise to several modulatory strategies by which they prevent exaggerated pathology and facilitate a longer worm survival. As little is known about the immunoregulatory potential of the zoonotic canine parasites Ancylostoma caninum and Toxocara canis in the natural host, the present study aimed to investigate whether their larval excretory-secretory (ES) products can modulate the canine immune system. We demonstrated TcES to increase the frequency of CD4+ Foxp3^high T cells, while both AcES and TcES were associated with elevated Helios expression in Foxp3^high lymphocytes. ES products were further capable of inducing IL-10 production by lymphocytes, which was mainly attributed to CD8+ T cells. ES treatment of PBMCs prior to mitogen stimulation inhibited polyclonal proliferation of CD4+ and CD8+ T cells. Moreover, monocyte-derived ES-pulsed dendritic cells reduced upregulation of MHC-II and CD80 in response to lipopolysaccharide. The data showed that regulation of the canine immune system by A. caninum and T. canis larvae comprises the modification of antigen-specific and polyclonal T cell responses and dendritic cell maturation.

Heterogeneity of macrophages in canine histiocytic ulcerative colitis

Histiocytic ulcerative colitis (HUC) is a chronic enteropathy which most notably occurs in Boxer dogs and French bulldogs. The inflamed mucosa is hallmarked by large, foamy, periodic acid–Schiff (PAS)-positive macrophages infiltrating the colonic mucosa. As little is known about their origin and phenotype, an immunohistochemical study was performed using different macrophage markers. Generally, canine colonic macrophages showed high expression of ionised calcium-binding adaptor molecule 1 and MHC class II. In canine HUC, macrophages revealed up-regulation of lysozyme and L1 Ag but decreased CD163 expression compared with controls, suggesting them to be pro-inflammatory cells, whereas the healthy colonic mucosa was characterised by an anti-inflammatory macrophage phenotype. In addition, PAS reaction was used to discriminate macrophage subpopulations. PAS– macrophages displayed higher expression of L1 Ag and CD64, whereas PAS+ cells, which were only present in HUC patients, were characterised by increased expression of lysozyme, inducible nitric oxide synthase and CD204. This indicates PAS+ cells to be mature macrophages contributing to the inflammatory process, which are most likely maintained by differentiation of immature PAS– macrophages continuously recruited from blood monocytes. In summary, macrophage heterogeneity in canine HUC probably illustrates their different maturation states and functions compared with the healthy animals.

Cutaneous form of maculopapular mastocytosis in a foal

BACKGROUND

Cutaneous mastocytosis is a rare benign disease occurring in domestic animals and humans. In previous reports, dermal findings in foals were accompanied by systemic mast cell infiltrations, whereas lesions in human cutaneous mastocytosis, including urticaria pigmentosa and solitary mastocytoma, are usually restricted to the skin.

OBJECTIVES

To describe a new variant of equine cutaneous maculopapular mastocytosis lacking systemic involvement.

ANIMALS

A 2.5-month-old warmblood foal with multiple skin nodules since birth.

METHODS

Clinical examination (including haematology, fine needle biopsy and thoracic radiographs), postmortem examination, histopathology and immunohistochemistry.

RESULTS

Clinical examination showed 41 skin nodules that contained numerous mast cells as detected by cytology. Macroscopic examination at postmortem examination revealed intradermal circumscribed lesions ranging from 2 to 5 cm in diameter. Histologically, they were composed of well differentiated mast cells with metachromatic granules stained with toluidine blue accompanied by many eosinophils. Immunohistochemically, mast cells had mast cell growth factor receptor c-KIT predominating at the cell surface and intracytoplasmic expression of tryptase. In other organs similar mast cell infiltrations were not detected.

CONCLUSIONS AND CLINICAL IMPORTANCE

The case presented here fulfils the criteria of equine cutaneous maculopapular mastocytosis (ECMM), representing a rare entity in foals that is reported to be associated with spontaneous regression, although the long-term prognosis is not known. Unlike in previous reports, lesions described here were restricted to the skin. This may imply that ECMM is primarily a dermal disease sharing similarities with urticaria pigmentosa in young children.

Histamine Receptor Expression in the Gastrointestinal Tract of Dogs

Histamine is an important mediator of many physiological processes including gastrointestinal function that acts via four different histamine receptors (H1R to H4R). Elevated histamine levels and increased HR messenger ribonucleic acid (mRNA) have been shown in humans with gastrointestinal disorders such as irritable bowel syndrome or allergic intestinal diseases. As there is limited knowledge concerning the distribution of histamine receptors (HR) in dogs, one aim of this study was to investigate the expression of histamine 1 receptor (H1R), histamine 2 receptor (H2R) and histamine 4 receptor (H4R) in the canine gastrointestinal tract at protein level using immunohistochemistry. Histamine 1 receptor, H2R and H4R were widely expressed throughout the canine gastrointestinal tract including epithelial, mesenchymal, neuronal and immune cells. In addition, in situ hybridisation was established for detecting canine H4R mRNA. Results showed H4R mRNA to be present in enterocytes, lamina propria immune cells and submucosal plexus in the duodenum and colon of nearly all investigated animals. The results elucidate the importance of HR in the canine gut and represent the basis for investigating their possible impact on canine inflammatory gastrointestinal disorders.

Congenital Ichthyosis in 14 Great Dane Puppies With a New Presentation

The present study describes a generalized congenital skin condition in 14 Great Dane puppies. Macroscopically, all dogs showed generalized gray to yellow scaling and skin wrinkles on the head and all 4 extremities. Skin sections were histologically examined using hematoxylin and eosin, Heidenhain's Azan, and Sudan red III staining methods and by conducting the alcian blue/periodic acid Schiff (AB/PAS) reaction technique on sections. Furthermore, incubation with hyaluronidase was performed. Skin samples were ultrastructurally analyzed using transmission electron microscopy. All affected Great Dane puppies had epidermal and follicular orthokeratotic hyperkeratosis, enlarged keratohyaline granules, vacuolated keratinocytes, and accumulations of an eosinophilic and alcianophilic, lipid-rich material within dilated hair follicular lumina and the cytoplasm of sebocytes. The macroscopic, histopathologic, and ultrastructural skin changes in all 14 Great Dane puppies indicate a new variant of a primary disorder of cornification with congenital, non-epidermolytic, lamellar ichthyosiform appearance.

Pathology in Captive Wild Felids at German Zoological Gardens

This retrospective study provides an overview on spontaneous diseases occurring in 38 captive wild felids submitted for necropsy by German zoological gardens between 2004 and 2013. Species included 18 tigers, 8 leopards, 7 lions, 3 cheetahs and 2 cougars with an age ranging from 0.5 to 22 years. Renal lesions, predominantly tubular alterations (intra-tubular concrements, tubular degeneration, necrosis, intra-tubular cellular debris, proteinaceous casts, dilated tubuli) followed by interstitial (lympho-plasmacytic inflammation, fibrosis, metastatic-suppurative inflammation, eosinophilic inflammation) and glomerular lesions (glomerulonephritis, glomerulosclerosis, amyloidosis) were detected in 33 out of 38 animals (87%). Tumors were found in 19 of 38 felids (50%) with 12 animals showing more than one neoplasm. The tumor prevalence increased with age. Neoplasms originated from endocrine (11), genital (8), lympho-hematopoietic (5) and alimentary organs (4) as well as the mesothelium (3). Most common neoplasms comprised uterine/ovarian leiomyomas (5/2), thyroid adenomas/adenocarcinoma (5/1), pleural mesotheliomas (3), hemangiosarcomas (2) and glossal papillomas (2). Inflammatory changes were frequently encountered in the intestine and the lung. Two young animals displayed metastatic mineralization suggestive of a vitamin D- or calcium intoxication. One tiger exhibited degenerative white matter changes consistent with an entity termed large felid leukoencephalomyelopathy. Various hyperplastic, degenerative and inflammatory changes with minor clinical significance were found in several organs. Summarized, renal lesions followed by neoplastic changes as well as inflammatory changes in lung and gastrointestinal tract represent the most frequent findings in captive wild felids living in German zoological gardens.

Canine gut dendritic cells in the steady state and in inflammatory bowel disease

Alongside the intestinal border, dendritic cells (DCs) sample large amounts of endogenous and potentially pathogenic antigens followed by initiation of protective immune responses or induction of tolerance. Breakdown of oral tolerance towards commensal bacteria is suggested to be crucial for the development of both human and canine inflammatory bowel disease (IBD). The aim of this study was to investigate canine intestinal DCs in the steady state and in dogs with IBD using multicolour immunofluorescence. In the healthy gut, DC-like cells expressed MHC II, CD1a8.2 and CD11c, and, in lower amounts, CD11b, within lamina propria, Peyer's patches (PPs) and mesenteric lymph nodes (MLNs), whereas those expressing CD80 and CD86 were only present in PPs and MLNs. Occasionally, DC-like cells were in contact with the intestinal lumen through transepithelial projections. In canine IBD, CD1a8.2+, CD11b+ and CD11c+ DC-like cells were decreased within the stomach, duodenum and colon, whereas the colonic mucosa revealed elevation of CD86+ DC-like cells. The complex network of DC-like cells in the gut indicates their important role in canine mucosal immunity, including active sampling of luminal antigens. Furthermore, their shift in diseased dogs suggests a pathogenetic significance for canine IBD.

Peripheral primitive neuroectodermal tumour in a dog

A 1-year-old German shepherd dog was presented with paraparesis quickly progressing to paraplegia. Magnetic resonance imaging revealed a large mass beneath the thoracolumbar vertebral column infiltrating the spinal canal and resulting in severe extradural compression of the spinal cord. Microscopically, this comprised a cell-rich unencapsulated tumour supported by fine bands of a fibrovascular stroma and occasionally forming primitive rosettes. Immunohistochemistry showed the tumour cells to express synaptophysin and neuron-specific enolase. Ultrastructurally, the neoplastic cells had low to moderate numbers of intracytoplasmic neurosecretory granules. A peripheral primitive neuroectodermal tumour was diagnosed. This is a rare embryonal tumour of neural origin that may have arisen from adrenal medulla, autonomic ganglia or peripheral nerves.

[Myocardiosis in a 6-month-old Lawson's Dragon (Pogona henrylawsonii)]

In a 6-month-old, chronically inappetent Lawsons's Dragon (Pogona henrylawsonii) with stunted growth a hyperdense cardiac region was found using radiology and computed tomography. At necropsy a profound necrosis of the myocardium with dystrophic calcification was diagnosed. In contrast to the frequently seen metastatic mineralisation of soft tissues, mainly due to poor husbandry, primary tissue destruction is the cause for dystrophic calcification. In reptiles, this is a rarely described form of calcification. Possible causes are infectious processes, nutritional or metabolic insufficiencies, intoxications or genetic components. In the presented case the aetiology could not be determined. In conclusion, dystrophic calcifications should be considered as a differential diagnosis in reptiles with soft tissue mineralisation.

Preorbital carcinoma in two Kirk's dik-diks (Madoqua kirkii)

Two Kirk's dik-diks suffered from chronic, unilateral, therapy-resistant enlargement of the preorbital gland. Computed tomographic imaging revealed a homogenous preorbital mass destroying the adjacent maxillary bone in one animal. Squamous cell carcinoma was diagnosed microscopically in both cases. Immunohistochemically, the neoplastic cells uniformly expressed cytokeratin (CK) 5/6 and CK14. Additionally, tumour cells were strongly labelled for p53 suggesting a possible role of this tumour suppressor gene in tumorigenesis. Chronic obstruction of the preorbital gland due to excessive accumulation of secretory products is considered as a likely cause of glandular and periglandular inflammation with subsequent malignant transformation.

Immunohistochemical investigation of Foxp3 expression in the intestine in healthy and diseased dogs

Intestinal immune regulation including development of oral tolerance is of great importance for the maintenance of intestinal homeostasis. Concerning this, regulatory T cells (Tregs) occupy a pivotal role in cell-mediated immunosuppression. Dysregulation of mucosal immunology leading to an abnormal interaction with commensal bacteria is suggested to play a key role in the pathogenesis of Inflammatory Bowel Disease (IBD) in men and dogs. The aim of this study was to characterise the expression of Foxp3 in the normal canine gut of 18 dogs (mean age: 6.03 years), in 16 dogs suffering from IBD (mean age: 5.05 years), and of 6 dogs with intestinal nematode infection (mean age: 0.87 years) using immunohistochemistry. In the duodenum, Tregs in healthy dogs declined from villi (median: 10.67/62 500 μm2) to crypts (median: 1.89/62 500 μm2). Tregs were further increased in the villi of middle-aged dogs (median: 18.92/62 500 μm2) in contrast to juvenile (median: 3.50/62 500 μm2) and old (median: 9.56/62 500 μm2) individuals. Compared to healthy controls, animals suffering from IBD revealed reduced numbers of Tregs in duodenal villi (median: 4.13/62 500 μm2). Dogs with intestinal nematode infection displayed increased numbers of Tregs (median: 21.06/62 500 μm2) compared to healthy animals.Age-related changes indicate a progressive establishment of oral tolerance and immunosenescence in the canine elderly. The results further suggest that a defect in Treg homeostasis may be involved in the pathogenesis of canine IBD. In contrast, increased numbers of Tregs in the duodenum may be due to nematode infection.

Synovial hemangioma in an adult horse

A 15-year-old gelding presented with a progressive lameness of the left forelimb of 2.5 months duration. Clinically, a dilation of the deep flexor tendon sheath with a firm elastic consistency and a pronounced tenderness was noted. Ultrasonically, a marked swelling of the flexor tendon sheath with an irregular density of the mesotendineum was observed. The white, firm material forming a nodular distension of the flexor tendon sheath with a diameter of approximately 1 cm was excised and sent for histopathological examination. Biopsies of the deep flexor tendon and corresponding tendon sheath were sent for histopathological evaluation. Histologically, the mass consisted of clefts and numerous anastomosing vascular channels extending between the collagen fibers of the deep flexor tendon. These capillary-like spaces were lined by neoplastic cells that were flattened to polygonal and contained few erythrocytes. There was 0 to 1 mitotic figure per 10 high power fields (400×). Immunohistochemically, the neoplastic cells stained positive for vimentin and factor VIII-related antigen. Adjacent to the neoplastic endothelial cells located pericytes expressed α-smooth muscle actin antigen. Based on the histopathological and immunohistochemical features, synovial hemangioma was diagnosed. One year after surgery, the horse has shown no lameness.

Identification of equine cutaneous lymphangioma by application of a lymphatic endothelial cell marker

An adult horse was presented with a mass located within the dermis and subcutis of the right forelimb. At post-mortem examination there was a marked increase in thickness of the subcutis of the right forelimb extending from the fetlock to the pectoral muscles. Microscopically, the dermis and subcutis were diffusely infiltrated by endothelial-like cells forming irregular channels and cavernous spaces. Immunohistochemical examination revealed the endothelial-like cells to express vimentin, factor VIII-related antigen and PROX-1, confirming the identity of the tumour as a lymphangioma. Ultrastructural analysis showed that the cavernous spaces were lined by a discontinuous endothelium lacking any basement membrane.

Intestinal lipid absorption increases cold ischemia of the small bowel in rats

The short cold ischemic tolerance of the gut is a major problem in small bowel transplantation. We have shown that intestinal lipid administration is beneficial during systemic inflammation like sepsis.

METHODS

Rats were intestinally infused with either water or 1% olive oil for 12 hours. The small bowel was removed and stored in HTK solution on ice. At t = 0, t = 60, t = 120, t = 180, t = 240, t = 300, t = 360, t = 420, and t = 480 minutes, a tissue sample of the gut was fixed, stained, and analyzed by three independent observers. Damage score was calculated (0 = no damage, 1 = minor damage, 2 = major damage, 3 = loss of structure) for integrity of the mucosa, integrity of the basal membrane of the mucosa, and integrity of villy. The damage score was allocated when all three observers agreed on the same or a higher damage score.

RESULTS

In all control animals minor damage for the integrity of the basal membrane occurred within 60 minutes, but in only 50% of the lipid-treated rats. In all control rats, major damage for both integrity of mucosa and villi occurred within 300 minutes or less, but only in 50% of the lipid-treated rats. In all control rats, the structure of the villi was completely lost within 480 minutes or less, whereas only 50% of the lipid treated animals reached maximal damage scores for either mucosa or villi.

CONCLUSION

Intestinal lipid administration before cold storage clearly decreases histologic damage of the small bowel and might increase the tolerance for cold ischemia. Lipids or their metabolites stored in enterocytes may act as an antiinflammatory. Intestinal lipid administration in organ donors might be useful to increase cold ischemic tolerance of the small bowel.

Delusions and delusional reasoning

In 2 studies, delusional participants assigned higher probabilities to narratives of actual delusions than participants with no history of delusions; previously delusional participants did not differ significantly from delusional participants or participants with no history of delusions. In Study 2, the authors found that this reasoning bias was specific to delusions and did not generalize to "neutral" text. Familiarity with the content of the delusion narratives played a mediating role in the estimation of their probability, but delusional status also had a significant, independent effect. These findings are consistent with the Bayesian model of delusion formation proposed by D. R. Hemsley and P. A. Garety (1986), and with R. P. Bentall, P. Kinderman, and S. Kaney's (1994) concept of "emotional saliency." A productive area of future research might be to further determine the elements of "emotional saliency" and their impact on the individual steps of the Bayesian model.

Delusions and delusional reasoning

In 2 studies, delusional participants assigned higher probabilities to narratives of actual delusions than participants with no history of delusions; previously delusional participants did not differ significantly from delusional participants or participants with no history of delusions. In Study 2, the authors found that this reasoning bias was specific to delusions and did not generalize to "neutral" text. Familiarity with the content of the delusion narratives played a mediating role in the estimation of their probability, but delusional status also had a significant, independent effect. These findings are consistent with the Bayesian model of delusion formation proposed by D. R. Hemsley and P. A. Garety (1986), and with R. P. Bentall, P. Kinderman, and S. Kaney's (1994) concept of "emotional saliency." A productive area of future research might be to further determine the elements of "emotional saliency" and their impact on the individual steps of the Bayesian model.

Delusions and symptom-consistent violence

OBJECTIVE

The study examined the extent to which delusions motivate violent behavior among psychiatric patients with a history of delusions.

METHODS

Fifty-four psychiatric inpatients identified by hospital staff as having delusions were interviewed about their history of delusions and incidents of violence that were concurrent with delusions. Raters used a 5-point scale to estimate the degree to which each reported incident of violence was motivated by a concurrent delusion. A second set of raters used a 5-point scale to estimate the severity of the violent incidents.

RESULTS

Raters' mean estimate indicated overall that violent incidents were probably not motivated by concurrent delusions. However, a significant minority of violent subjects (40 percent) reported at least one violent incident that was judged to be probably or definitely motivated by a concurrent delusion. A smaller subgroup of violent subjects (17.5 percent) reported at least one incident that was judged to be both extremely violent and definitely motivated by a concurrent delusion.

CONCLUSIONS

Delusional motivation of violence is rare, but a moderate risk exists that delusions will motivate violence at some time during the course of a violent patient's illness.

Psychosis and violence: the case for a content analysis of psychotic experience

There has been a great deal of debate about the dangers psychiatric patients pose to the general population. Recent studies appear to confirm a moderate but reliable association between mental illness and violence. The nature of this association, however, is unresolved. Considerable evidence suggests that much of the violent behavior observed in the mentally ill is not random but is motivated and directed by psychotic symptoms. In many cases, the behavior appears to be a predictable and in some ways rational response to irrational beliefs (delusions) and perceptions (hallucinations). The content and themes of a psychotic patient's delusion or hallucination often imply a specific course of violent action. Unlike studies of associations between violence and broad categories of subject characteristics (e.g., mental illness), an analysis of the association between violence and the content and themes of psychotic symptoms could be much more informative. Conceivably, such an analysis could identify not only psychiatric patients at risk for committing violence but also those individuals who are at risk for becoming targets of their violence.

Command hallucinations and the prediction of dangerousness

OBJECTIVES

Recent studies have supported the belief that command hallucinations can induce dangerous behavior. This study tried to replicate previous findings that compliance with the command was associated with delusions related to hallucinations and the ability to identify the hallucinated voice. This study also assessed the association between compliance and the dangerousness of the command, chronicity of illness, a diagnosis of schizophrenia, and past compliance with hallucinated commands.

METHODS

The most recent command hallucination reported by 93 psychiatric inpatients was rated for level of dangerousness and level of compliance with the command.

RESULTS

Subjects who experienced less dangerous commands or who could identify the hallucinated voice reported higher levels of compliance, although reported compliance with more dangerous commands was not uncommon. Commands experienced in the hospital were less dangerous than those experienced elsewhere and tended to be specific to the hospital environment. Subjects were less likely to comply with commands experienced in the hospital.

CONCLUSIONS

Based on their self-reports, psychiatric patients who experience command hallucinations are at risk for dangerous behavior. Ability to identify the hallucinated voice is a fairly reliable predictor of reported compliance. Level of dangerousness resulting from compliance with command hallucinations may be a function of the patient's environment.

Mood theme and bizarreness of delusions in schizophrenia and mood psychosis

Narratives of the delusions of 83 schizophrenic and 55 nonschizophrenic psychiatric subjects were categorized as of one or more of 12 types. Narratives were also independently assessed along dimensional scales of bizarreness and mood theme. Schneiderian and grandiose types were found to be more common in schizophrenics and mood psychotics, respectively. Dimensional measures showed that the delusions of schizophrenics were more unlikely and that those of mood psychotics had a stronger mood theme. Regression analysis determined that Schneiderian delusions and a dimensional estimate of mood theme best differentiated schizophrenics from mood psychotics. Assessments along dimensions of other parameters, particularly those represented by Schneiderian delusions, may further discriminate the functional psychoses.

Mood theme and bizarreness of delusions in schizophrenia and mood psychosis

Narratives of the delusions of 83 schizophrenic and 55 nonschizophrenic psychiatric subjects were categorized as of one or more of 12 types. Narratives were also independently assessed along dimensional scales of bizarreness and mood theme. Schneiderian and grandiose types were found to be more common in schizophrenics and mood psychotics, respectively. Dimensional measures showed that the delusions of schizophrenics were more unlikely and that those of mood psychotics had a stronger mood theme. Regression analysis determined that Schneiderian delusions and a dimensional estimate of mood theme best differentiated schizophrenics from mood psychotics. Assessments along dimensions of other parameters, particularly those represented by Schneiderian delusions, may further discriminate the functional psychoses.

Time series analysis of obsessional behavior and mood during self-imposed delay and response prevention

Time series analysis of more than a year of daily self-report of three subjects showed that self-imposed delay and response prevention was effective in decreasing obsessions and compulsions. The subject-controlled treatment had a varied effect on mood-anxiety decreased in two subjects, but depression increased in one. (A similar worsening of mood after elimination of obsessional behavior was found in a previous case study.) Apparently, successful treatment of obsessional behavior will not necessarily lead to an improvement in mood. Concurrent mood symptoms need to be targeted separately; and, plans should be made to deal with mood symptoms that may occur once obsessional behavior is removed.

Predicting compliance with command hallucinations

Of 44 patients who experienced command hallucinations, those with hallucination-related delusions and hallucinatory voices they could identify were more likely to comply with the commands. The danger of the behaviors specified by the hallucinations did not appear to be a factor in compliance.

Psychiatric hospitalization and community-based program attendance

The psychiatric rehabilitation model of community-based treatment programs for chronic psychiatric patients advocates the teaching of community living skills. Learning these skills requires program attendance, and there is some evidence that consistent attenders are less likely to be hospitalized. This study describes a psychiatric rehabilitation program that resulted in a decrease in number of subsequent psychiatric hospitalizations. However, this decrease was unrelated to program attendance; the number of hospitalizations in the year prior to enrollment was by far the best predictor of hospitalization. Changes in perception of the patient's support network by persons making hospitalization decisions was offered as one possible explanation for the effectiveness of some community-based programs.

Summation of arousal in partial fetishism

A summation model of classical conditioning was used to describe the deviant sexual arousal pattern of a male psychiatric patient. Penile assessment showed a response to a compound stimulus (radio static plus a picture of a woman) that was approximately equal to the sum of the responses to each component alone. The subject's self-report of sexual arousal followed a similar pattern. A distinction was made between total and partial fetishism. It was suggested that what may be particularly troublesome in partial fetishism is the potential for high levels of summated arousal.

Spontaneous exposure and "self-control" in the treatment of compulsive checking

This case study describes a treatment developed for an obsessional patient for whom neither in vivo nor verbal exposure was effective in eliciting obsessional thinking. The treatment consisted of increasingly more strict temporal parameters the patient was to impose when obsessional thoughts spontaneously occurred. These parameters stipulated the amount of time he was to wait between the occurrence of obsessional thoughts and compulsive checking, and the amount of time he was to spend checking. Over a period of several months, these self-imposed temporal parameters were effective in completely eliminating persistent and intractable obsessional thinking of 11 years' duration.

Vocal activity in verbal hallucinations

Vocal and forearm EMGs were recorded from 19 hallucinating and 22 nonhallucinating psychiatric inpatients. A microphone placed close to the lips was used to detect subvocal speech. The subjects' EMG and subvocal responses to pre-recorded statements were also assessed. Subjects who experienced hallucinations during assessment were asked to estimate the frequency of their hallucinations and rate phenomenological of their most recent hallucination. Results essentially replicated studies that found increased vocal potentials in hallucinators, but also showed that these increased potentials were nonsignificant when nonvocal measures are included in the statistical analysis. Subvocal speech and coincident increases in vocal EMG with reports of hallucinations, and with reports of pre-recorded statements, were not found. A significant negative correlation was found between the mean vocal potential of hallucinators and the perceived location of their most recent hallucination. The pre-recorded statements were generally perceived to be louder, clearer and more outside the head than the most recent hallucination.

Self-report of the frequency and phenomenology of verbal hallucinations

This study was an assessment of several parameters of verbal hallucinations ("voices") based on the self-report of 52 hallucinating psychiatric patients. These subjects were asked to estimate the frequency of their hallucinations and to rate phenomenological aspects (loudness, clarity, location, reality) of their most recent hallucination. Each parameter was assessed with two visual analogue scales which differed in their wording of the dimension. Results showed that the reliability of the subjects' estimates on the parameters differed greatly. Clarity was most reliably reported and reality was least reliably reported. Historical notions that schizophrenics characteristically perceive external "voices" and that such "voices" are perceived as more real were not supported. There was a significant negative correlation between the perceived location and the perceived clarity of hallucinations. No significant differences in mean parameter scores were found between two groups of subjects, schizophrenics and affective psychotics.

Multitreatment of obsessive-compulsive checking in a geriatric patient

Behavioral treatment of an elderly woman with an obsessive-complusive disoder is discussed in an attempt to illustrate: (1) the value of verbal exposure to feared stimuli in the treatment of fears that are difficult to elicit reliably in vivo, and (2) the effectiveness of behavioral techniques with geriatric patients.

Reactivity of self-monitoring procedures with retarded adolescents

The reactivity of self-monitoring procedures with retarded adolescents was investigated using single-case designs. The effects of two variables, social reinforcement and feedback, on the degree of reactivity were also examined. Both subjects monitored a socially undesirable behavior and were asked to self-record for extended periods of time with minimal cues from the environment. The results indicated that self-monitoring produced reactive decreases in the target behavior. Reinforcement had a differential effect across subjects, further altering the target behavior for only one subject. Feedback decreased the behavior for the second subject. The subjects' accuracy in self-recording was quite low.