Nitric oxide and TNF-alpha trigger colonic inflammation and carcinogenesis in Helicobacter hepaticus-infected, Rag2-deficient mice.

Recombinase-activating gene-2-deficient (Rag2(-/-)) mice lacking functional lymphocytes provide a useful model of chronic inflammatory bowel disease-emulating events in human colon cancer. Infection of Rag2(-/-) mice with Helicobacter hepaticus led to accumulation of macrophages and neutrophils in the colon, a process temporally related to up-regulation of tissue inducible nitric oxide synthase (iNOS) expression at the site of infection and increased nitric oxide (NO) production, as evidenced by urinary excretion of nitrate. Progressive development of increasingly severe inflammation, hyperplasia, dysplasia, and cancer accompanied these changes. Concurrent administration of an iNOS inhibitor prevented NO production and abrogated epithelial pathology and inhibited the onset of cancer. The presence of Gr-1(+) neutrophils and elevated tumor necrosis factor-alpha (TNF-alpha) expression in colon were required for increased iNOS expression and cancer, whereas interleukin-10 (IL-10) down-regulated TNF-alpha and iNOS expression and suppressed cancer. Anti-inflammatory CD4(+) regulatory lymphocytes also down-regulated iNOS and reduced cancer formation. Collectively, these results confirm essential roles for inflammation, increased TNF-alpha expression, and elevated NO production in colon carcinogenesis.

Microbes and Oxytocin: Benefits for Host Physiology and Behavior.

It is now understood that gut bacteria exert effects beyond the local boundaries of the gastrointestinal tract to include distant tissues and overall health. Prototype probiotic bacterium Lactobacillus reuteri has been found to upregulate hormone oxytocin and systemic immune responses to achieve a wide array of health benefits involving wound healing, mental health, metabolism, and myoskeletal maintenance. Together these display that the gut microbiome and host animal interact via immune-endocrine-brain signaling networks. Such findings provide novel therapeutic strategies to stimulate powerful homeostatic pathways and genetic programs, stemming from the coevolution of mammals and their microbiome.

Functional and genetic characterization of the oligomerization and DNA binding properties of the Drosophila doublesex proteins.

The doublesex (dsx) gene of Drosophila melanogaster encodes both male-specific (DSXM) and female-specific (DSXF) polypeptides, which are required for normal differentiation of numerous sexually dimorphic somatic traits. The DSX polypeptides are transcription factors and have been shown previously to bind through a zinc finger-like domain to specific sites in an enhancer regulating sex-specific expression of yolk protein genes. We have determined the consensus target sequence for this DNA binding domain to be a palindromic sequence AGNNACTAAATGTNNTC composed of two half-sites around a central (A/T) base pair. As predicted by the symmetric nature of this site, we have found that the DSX proteins exist as dimers in vivo and have mapped two independent dimerization domains by the yeast two-hybrid method; one in the non-sex-specific amino-terminal region of the protein and one that includes the partially sex-specific carboxy-terminal domains of both the male and female polypeptides. We have further identified a missense mutation that eliminates dsx function in female flies, and shown that the same mutation prevents dimerization of DSXF in the yeast two-hybrid system, indicating a critical role for dimerization in dsx function in vivo.

Malignant lymphoma in ferrets: clinical and pathological findings in 19 cases.

The clinical and pathological findings in 19 ferrets (Mustela putorius furo) with malignant lymphoma are reviewed. Peripubescent ferrets had rapidly progressive stage IV high grade immunoblastic or small non-cleaved cell lymphoma. Adult ferrets had stage II or IV low grade diffuse small lymphocytic (DSL) lymphoma, stage IV high grade small non-cleaved cell lymphoma, or stage IV high grade immunoblastic polymorphous (IBP) lymphoma. Three ferrets had concurrent IBP and DSL lymphoma involving different organs. The IBP admixture of immunoblasts, large atypical lymphocytes, Reed-Sternberg-like cells, lymphoblasts and small lymphocytes has been associated with certain retrovirally associated lymphomas and nodal hyperplasias in man, non-human primates and cats. Aleutian disease, a parvovirus-induced lymphoproliferative disease, also involves clinical and histological features similar to certain lymphomas in ferrets. Seven ferrets tested were seronegative for feline leukaemia virus antigen. Only one of eight ferrets was positive for Aleutian parvovirus antibody. The clinical and pathological findings are suggestive of a viral aetiology for certain lymphomas in ferrets.

Immunophenotypic characterization of lymphomas from the mediastinum of young ferrets.

OBJECTIVE: To determine the phenotype of naturally developing lymphomas in young ferrets. ANIMALS: 10 ferrets with lymphoma. PROCEDURE: Neoplastic tissues were graded histologically according to the National Cancer Institute's Working Formulation for non-Hodgkin's lymphoma and phenotype was determined by means of immunohistochemical staining. A polyclonal anti-human CD3 and a monoclonal anti-human CD79 antibody were used to classify the lymphomas in situ as T-cell or B-cell origin. Specificity of antibodies was determined by evaluating lymphoid tissue from normal ferrets in situ, which was confirmed by western blot analyses. RESULTS: All 10 ferrets had clinically aggressive tumors, irrespective of the phenotype. Nine ferrets had T-cell lymphoma that extensively involved the mediastinum. Remnants of thymic tissue, indicative of thymic origin, were identified in lymphoma of these 9 ferrets. One ferret had a B-cell multicentric lymphoma without involvement of the mediastinum. CONCLUSIONS: The majority of lymphomas in these young ferrets involved the mediastinum and were of T-cell phenotype. Impact for Human Medicine-There are many similarities between the lymphoma syndrome of ferrets and the condition documented for cats and children with lymphoma of the mediastinal area. CLINICAL RELEVANCE: Differential diagnoses for young ferrets with clinical signs of lethargy or respiratory distress should include T-cell lymphoma of the mediastinum.

Clinical and pathologic findings in ferrets with lymphoma: 60 cases (1982-1994).

OBJECTIVE: To examine clinical and pathologic findings in 60 ferrets with lymphoma. DESIGN: Retrospective case series. ANIMALS: 60 ferrets in which the diagnosis of lymphoma had been confirmed by means of histologic examination of biopsy or necropsy specimens. PROCEDURE: Information including age, sex, coat color, history, clinical signs, clinicopathologic abnormalities, treatment, outcome, and results of histologic examination of biopsy and necropsy specimens were retrieved from medical records of ferrets with spontaneous lymphoma examined between 1982 and 1994 at the Massachusetts institute of Technology or private veterinary practices in 10 states. Classification of lymphoma was assigned according to the National Cancer Institute's working formulation for non-Hodgkin's lymphomas. Chi 2 Trend analysis was used to determine whether age was associated with history, clinical signs, hematologic abnormalities, stage, histologic grade, or outcome. RESULTS: Acute onset, mediastinal mass, lymphocytosis, and multicentric distribution were linked with younger ferrets, and lymphopenia and survival longer than 2 months after diagnosis was associated with older ferrets. Twenty percent of ferrets in this study had cohabitated with another ferret with lymphoma. Chemotherapeutic efficacy was not evaluated. CLINICAL IMPLICATIONS: Clinical and pathologic features linked with age should be considered when evaluating diagnostic and therapeutic options for ferrets with lymphoma.

Probiotic 'glow of health': it's more than skin deep.

Radiant skin and hair are universal indicators of good health. It was recently shown that feeding of probiotic bacteria to aged mice rapidly induced youthful vitality characterised by thick lustrous skin and hair, and enhanced reproductive fitness, not seen in untreated controls. Probiotic-treated animals displayed integrated immune and hypothalamic-pituitary outputs that were isolated mechanistically to microbe-induced anti-inflammatory interleukin-10 and neuropeptide hormone oxytocin. In this way, probiotic microbes interface with mammalian physiological underpinnings to impart superb physical and reproductive fitness displayed as radiant and resilient skin and mucosae, unveiling novel strategies for integumentary health.

Helicobacter hepaticus infection in mice: models for understanding lower bowel inflammation and cancer.

Pioneering work in the 1990s first linked a novel microaerobic bacterium, Helicobacter hepaticus, with chronic active hepatitis and inflammatory bowel disease in several murine models. Targeted H. hepaticus infection experiments subsequently demonstrated its ability to induce colitis, colorectal cancer, and extraintestinal diseases in a number of mouse strains with defects in immune function and/or regulation. H. hepaticus is now widely utilized as a model system to dissect how intestinal microbiota interact with the host to produce both inflammatory and tolerogenic responses. This model has been used to make important advances in understanding factors that regulate both acquired and innate immune response within the intestine. Further, it has been an effective tool to help define the function of regulatory T cells, including their ability to directly inhibit the innate inflammatory response to gut microbiota. The complete genomic sequence of H. hepaticus has advanced the identification of several virulence factors and aided in the elucidation of H. hepaticus pathogenesis. Delineating targets of H. hepaticus virulence factors could facilitate novel approaches to treating microbially induced lower bowel inflammatory diseases.

The Drosophila doublesex proteins share a novel zinc finger related DNA binding domain.

The doublesex gene of Drosophila melanogaster is the final member of a well characterized hierarchy of genes that controls somatic sex determination and differentiation. The male-specific and female-specific doublesex polypeptides occupy a terminal position in the hierarchy, and thus regulate those genes responsible for the development of sexually dimorphic characteristics of the fly. To investigate the molecular mechanism by which these two related proteins interact with specific target genes, we have identified and characterized their DNA binding domains. Using gel mobility shift experiments with sequentially deleted polypeptides, site-directed mutagenesis and spectrophotometric assays, we have shown that the two doublesex proteins share a common and novel zinc finger-related DNA binding domain distinct from any reported class of zinc binding proteins. We have further shown that of 10 null dsx alleles, six encode proteins deficient in DNA binding activity, and that three of these alleles are the result of mutations that alter cysteine and histidine residues in the metal binding domain. Our results provide evidence that both the male-specific and female-specific doublesex proteins share and depend upon the same DNA binding domain for function in vivo, suggesting that both proteins bind to, but differentially regulate, a common set of genes in both sexes.

A comparison of ketamine/xylazine and ketamine/xylazine/acepromazine anesthesia in the rabbit.

Parenteral anesthetic combinations such as ketamine and xylazine have become the agents of choice for anesthesia in the rabbit, because they are effective, easily administered and inexpensive. A number of recent reports have recommended including acepromazine in this combination, but a critical evaluation of this combination in the rabbit has not been reported. Five adult New Zealand white rabbits were anesthetized intramuscularly with ketamine (35 mg/kg) and xylazine (5 mg/kg) with or without acepromazine (0.75 mg/kg). The study was conducted in a double blind fashion, where each rabbit was administered both combinations at a minimum of 7 day intervals. Physiologic parameters were evaluated including heart rate, respiratory rate, central arterial blood pressure, pedal, palpebral and postural reflex activity. The duration of general anesthesia, estimated by the time elapsed between the loss and return of the palpebral reflex, was greater (means = 99 +/- 20 minutes) when acepromazine was employed in the combination compared to (means = 77 +/- 5 minutes) when ketamine/xylazine were used alone. Mean central arterial blood pressure reached a lower level when acepromazine was utilized (means = 46 +/- 8 mm/Hg) than when it was not (means = 57 +/- 12 mm/Hg.). The addition of acepromazine in a ketamine/xylazine combination resulted in a 28% longer period of anesthesia, a 19% lower mean central arterial blood pressure and a 32% longer recovery of postural reflexes. The ketamine/xylazine/acepromazine combination is a useful regimen for normovolemic animals when anesthetic duration greater than that produced by ketamine/xylazine alone is required.

Intestinal plasmacytosis in rabbits: a histologic and ultrastructural study.

A retrospective study revealed intestinal plasmacytosis in 53 of 102 rabbits used in various experimental studies and as controls. The breeds affected included New Zealand white (n = 46), Dutch-belted (n = 6), and Watanabe (n = 1) rabbits. Sex predisposition was not found in any breed. The mean (+/-SD) ages were 3.1 +/- 1.4 years for New Zealand white rabbits, 1.3 +/- 1.1 for Dutch-belted rabbits, and 2 years for the Watanabe rabbit. The severity increased with animal age. The incidence was higher (P < 0.05) in rabbits used in antibody production and cholesterol studies. The lesions were characterized by multifocal to diffuse infiltration of well-differentiated plasma cells in the intestinal mucosa. Electron microscopic examination revealed typical plasma cell morphology of the infiltrating cells. Small intestine and cecum were the major sites affected. In severe cases, colon, rectum, trachea, esophagus, mesenteric lymph node, and spleen were also involved.

Cystic urogenital anomalies in ferrets (Mustela putorius furo).

Single or multiple semispherical to bilobulated fluid-filled cystic structures of variable size were observed on the dorsal aspects of the urinary bladder of four male and two female ferrets (Mustela putorius furo). All ferrets had been neutered. On physical examination, the cysts were palpated as caudal abdominal masses. Three of the six ferrets presented with dysuria, and two ferrets had signs compatible with endocrine dysfunction. Adrenal cortical hyperplasia or neoplasia were observed in all of the five ferrets examined. Sex hormones assayed in one of the six ferrets revealed elevated levels of serum estrodiol. The posterior aspect of the cysts was located on and/or attached to the trigone or neck of the bladder, with variable intraluminal communication with the bladder and/or the urethra. The anterior aspect of the cysts projected dorsally or dorsocranially into the caudal abdomen. The cysts were thin walled and contained urinelike fluid (n = 5) or viscous yellow fluid (n = 1). Histologically, the cyst walls were composed of three layers, epithelium, muscle, and serosa, with fibrovascular stroma between layers. The epithelium consisted of simple to stratified transitional, columnar, or squamous epithelial cells. The muscular layer consisted of intermittent bundles and/or single to double layers of continuous to discontinuous smooth muscle. The serosal layer consisted of loose fibrous stroma covered by flattened mesothelial cells. The cystic anomalies in these ferrets were most likely derived from the urogenital glands/ducts or other remnants.

A cluster of cases of juvenile mediastinal lymphoma in a ferret colony.

Three cases of juvenile mediastinal lymphoma developed in a laboratory colony of ferrets. Two ferrets became acutely moribund, and one was found dead with no preceding signs of illness. Splenomegaly, hepatomegaly, and a large thoracic mass were the primary features in each case. All three ferrets had multiorgan metastasis of the tumor. Two ferrets were tested for feline leukemia virus and Aleutian disease virus with negative results.

Helicobacter mustelae-associated gastric MALT lymphoma in ferrets.

Gastric lymphoma resembling gastric mucosa-associated lymphoid tissue (MALT) lymphoma linked with Helicobacter pylori infection in humans was observed in ferrets infected with H. mustelae. Four ferrets with ante- or postmortem evidence of primary gastric lymphoma were described. Lymphoma was diagnosed in the wall of the lesser curvature of the pyloric antrum, corresponding to the predominant focus of H. mustelae induced gastritis in ferrets. Two ferrets had low-grade small-cell lymphoma and two ferrets had high-grade large-cell lymphoma. Gastric lymphomas demonstrated characteristic lymphoepithelial lesions, and the lymphoid cells were IgG+ in all ferrets. Lymphoma was confirmed by light chain restriction, which contrasted with the 1.2:1 kappa lambda ratio observed in H. mustelae-associated chronic gastritis. H. mustelae infection in ferrets has been used as a model for gastritis, ulcerogenesis, and carcinogenesis. The ferret may provide an attractive model to study pathogenesis and treatment of gastric MALT lymphoma in humans.

Transmission of a chronic lymphoproliferative syndrome in ferrets.

BACKGROUND: Lymphomas and leukemias are caused by transmissible viruses in a wide variety of species, including humans, cattle, and cats. Features of lymphoma in ferrets suggest that it, too, may have an infectious etiology. No agent has been identified. EXPERIMENTAL DESIGN: Cells or cell-free inocula from a ferret with spontaneous malignant lymphoma were administered i.p. to six recipient ferrets. Two ferrets received fresh cells, two received frozen cells, and two received cell-free culture supernatant. The recipients were monitored routinely clinically and hematologically, and lymphoma was confirmed histologically. The lymphomas were characterized using cytology, cytochemistry, immunophenotyping, and histology. Cultivated cells from the donor and recipients were examined using reverse transcriptase assay, microscopy, and electron microscopy. RESULTS: All of the six recipient ferrets developed mild sustained lymphocytosis within 6 weeks of the inoculation. Two of six were euthanized 14 to 18 months after inoculation. Lymphoma was later diagnosed in three of the four remaining ferrets at 24 to 36 months after inoculation. All developed a chronic indolent syndrome featuring profound splenomegaly, lymphocytosis with atypia, and histologically polymorphous lymphoma. Two of the three who developed lymphoma had received fresh donor lymphoma cells, and the third had received supernatant from donor cell cultures with elevated reverse transcriptase activity. Cultivated cells from the affected ferrets demonstrated reverse transcriptase activity and retrovirus-like particles. CONCLUSIONS: This study demonstrates horizontal transmission of malignant lymphoma in ferrets using cell or cell-free inocula. Clinical and pathologic features of this syndrome in ferrets resembled virally induced lymphomas in other species.

Pregnancy toxemia in the European ferret (Mustela putorius furo).

BACKGROUND AND OBJECTIVE: Pregnancy toxemia may lead to appreciable mortality among jills and their offspring. The objective of this report was to increase awareness of the disease, its likely cause, and practical prevention and treatment measures. METHODS: Ten cases of pregnancy toxemia were evaluated. Jills were in late gestation (mean, 38 days; range, 34 to 42 days) and had large litters (mean, 11.5 kits; range, 7 to 15 kits). RESULTS: The most common clinical signs of disease were lethargy, inappetence, dehydration, and excess shedding. Hematologic and clinical biochemical abnormalities included anemia (4 of 8 jills tested), hypoproteinemia (5 of 7), azotemia (7 of 7), hypocalcemia (5 of 6), hyperbilirubinemia (3 of 3), and high liver enzyme activities (6 of 6). Two jills were found dead; two jills were euthanized, six received supportive treatment, and cesarean section was performed on five. The three jills that survived tended to have less pronounced azotemia, hypoproteinemia, and liver enzyme activity increases and were not anemic. Hepatic lipidosis was observed grossly in all jills that died and was confirmed by histologic examination in four jills. CONCLUSIONS: Pregnancy toxemia in ferrets resembles metabolic diseases in several other animal species and requires aggressive treatment, including supportive care, nutritional supplementation, and cesarean section. Maintaining adequate nutrition and avoiding stress late in gestation may prevent the disease.

Hepatobiliary inflammation, neoplasia, and argyrophilic bacteria in a ferret colony.

Hepatobiliary disease was diagnosed in eight of 34 genetically unrelated cohabitating pet ferrets (Mustela putorios furo) during a 7-year period. The eight ferrets ranged in age from 5 to 8 years and exhibited chronic cholangiohepatitis coupled with cellular proliferation ranging from hyperplasia to frank neoplasia. Spiral-shaped argyrophilic bacteria were demonstrated in livers of three ferrets, including two with carcinoma. Sequence analysis of a 400-base pair polymerase chain reaction product amplified from DNA derived from fecal bacteria from one ferret demonstrated 98% and 97% similarity to Helicobacter cholecystus and Helicobacter sp. strain 266-1 , respectively. The clustering of severe hepatic disease in these cohabitating ferroes suggests a possible infectious etiology. The role of Helicobacter species and other bacteria in hepatitis and/or neoplasia in ferrets requires further study.

Clusters of lymphoma in ferrets.

Cluster outbreaks of lymphoma and leukemia have been associated with viral infections in many species including humans, cattle, and cats. This study describes epidemiological, clinical, and pathological features of cluster outbreaks of lymphoma in multiferret households and examines and compares the Aleutian disease virus (ADV) and feline leukemia virus (FeLV) status of cases, ferrets at risk, and controls. Three ferret groups with 21 cases of histologically diagnosed lymphoma (12.6% cumulative incidence) and their cohabitants (n = 35) were examined and compared with three control groups (n = 52) of cohabitating ferrets without lymphoma. A familial distribution was observed in one group but most cases were not consanguinous. Ferrets greater than 3 years of age developed chronic disease in two of the groups and 2-year-old adults had acute disease in the remaining group. Lymphocytosis, splenomegaly, and lymphadenopathy were prominent features. Histologically, predominantly small noncleaved cell and polymorphous lymphoid lesions were observed. All of the ferrets with lymphoma that were tested for ADV and FeLV using serology or PCR were negative. The rate of ADV antibody among cases or ferrets at risk was not significantly different from controls. None of the cluster ferrets were seropositive for FeLV p27 antigen using a monoclonal ELISA. Infection with a novel ferret virus is suspected, but an etiological agent has not yet been identified.