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Biomedical subjects

K Allenspach

Publications and source records attributed to K Allenspach.

14 recordsLinked to original sources

Effects of probiotic bacteria in dogs with food responsive diarrhoea treated with an elimination diet.

We evaluated whether a probiotic supplementation in dogs with food responsive diarrhoea (FRD) has beneficial effects on intestinal cytokine patterns and on microbiota. Twenty-one client-owned dogs with FRD were presented for clinically needed duodeno- and colonoscopy and were enrolled in a prospective placebo (PL)-controlled probiotic trial. Intestinal tissue samples and faeces were collected during endoscopy. Intestinal mRNA abundance of interleukin (IL)-5, -10, -12p40 and -13, tumour necrosis factor-alpha, transforming growth factor-beta1 and interferon (IFN)-gamma were analysed and numbers of Lactobacillus spp., Bifidobacterium spp., Enterococcus spp. and Enterobacteriaceae and supplemented probiotic bacteria were determined in faeces. The Canine Inflammatory Bowel Disease Activity Index, a scoring system comprising general attitude, appetite, faecal consistency, defecation frequency, and vomitus, decreased in all dogs (p < 0.0001). Duodenal IL-10 mRNA levels decreased (p = 0.1) and colonic IFN-gamma mRNA levels increased (p = 0.08) after probiotic treatment. Numbers of Enterobacteriaceae decreased in FRD dogs receiving probiotic cocktail (FRD(PC)) and FRD dogs fed PL (FRD(PL)) during treatment (p < 0.05), numbers of Lactobacillus spp. increased in FRD(PC after) when compared with FRD(PC before) (p < 0.1). One strain of PC was detected in five of eight FRD(PC) dogs after probiotic supplementation. In conclusion, all dogs clinically improved after treatment, but cytokine patterns were not associated with the clinical features irrespective of the dietary supplementation.

Animal Feed↗

Evaluation of colonoscopic allergen provocation as a diagnostic tool in dogs with proven food hypersensitivity reactions.

OBJECTIVE: To evaluate the colonoscopic allergen provocation (COLAP) test as a new tool for the diagnosis of IgE-mediated food allergy. METHODS: Oral food challenges as well as COLAP testing were performed in a colony of nine research dogs with proven immediate-type food allergic reactions. In addition, COLAP was performed in five healthy dogs. RESULTS: When compared with the oral challenge test, COLAP accurately determined 18 of 23 (73 per cent) positive oral challenge reactions (73 per cent) in dogs with food allergies and was negative in the healthy dogs. CLINICAL SIGNIFICANCE: The accuracy of this new test may be higher than that for gastric sensitivity testing. Therefore, COLAP holds promise as a new test to confirm the diagnosis of suspect IgE-mediated food allergy in dogs.

Allergens↗

P-glycoprotein expression in lamina propria lymphocytes of duodenal biopsy samples in dogs with chronic idiopathic enteropathies.

P-glycoprotein (p-gp) is a transmembrane protein functioning as a drug-efflux pump in the intestinal epithelium. Human patients with inflammatory bowel disease (IBD) who fail to respond to treatment with steroids express high levels of p-gp in lamina propria lymphocytes. The purpose of this study was to investigate p-gp expression in duodenal biopsy samples of dogs with chronic enteropathies and to evaluate the expression of p-gp after treatment with a known inducer of p-gp (prednisolone). Duodenal biopsy samples from 48 dogs were evaluated immunohistochemically with the mouse monoclonal antibody C219 for expression of p-gp in lamina propria lymphocytes. Biopsy samples were available from 15 dogs after treatment with prednisolone and 16 dogs after dietary therapy alone ("elimination diet"). Treatment with prednisolone resulted in an increase in p-gp expression (P=0.005). In contrast, dietary treatment alone produced no significant change in p-gp expression (P=0.59). A low p-gp score before initiation of steroid treatment was significantly associated with a positive response to treatment (P=0.01). These results indicate that lamina propria lymphocyte expression of p-gp is upregulated after prednisolone treatment in dogs with IBD, and that mucosal expression of p-gp may be of value in predicting the response to therapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Cytokine expression in an ex vivo culture system of duodenal samples from dogs with chronic enteropathies: modulation by probiotic bacteria.

There is evidence that probiotics have immune-modulating effects on intestinal inflammation during chronic enteropathies (CE). In an ex vivo culture system we investigated the influence of probiotics on mRNA and protein expression levels of cytokines in intestinal samples from dogs suffering from CE. Duodenal samples of client-owned dogs with CE (group CE; n = 12) were collected during diagnostic endoscopy. Additional duodenal samples of gastrointestinally healthy dogs (group C; n = 4) from an unrelated study were available. Based on histopathological analyses, no pathological changes or only mild to moderate eosinophilic and/or lymphoplasmacytic duodenitis were diagnosed. Tissue samples were cultured: (1) with cell culture medium alone (negative control), (2) with a probiotic cocktail (PC), constituted of three Lactobacilli spp. from healthy canine fecal isolates, (3) with the individual strains of PC, and (4) with a placebo powder. Viability of intestinal tissue and probiotic bacteria before and after culture was evaluated. The mRNA abundance of interleukin (IL)-10, IL-12p40, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, and transforming growth factor (TGF)-beta1 was analyzed by real-time polymerase chain reaction (RT-PCR). Protein concentrations of IFN-gamma and IL-10 were measured in culture supernatant by ELISA. Results of RT-PCR were expressed as 2(-2DeltaCrossing Point) x 100 after normalization with beta-actin. There was a loss of about 1 log CFU/mL of probiotic bacteria during the incubation period. Viability of tissue was maintained as confirmed by non-significant release of lactate dehydrogenase. In C, addition of PC increased IL-10 mRNA levels (P < 0.1). In CE, PC increased mRNA and protein levels of IL-10 (P < 0.05). On the mRNA level, the ratio of TNFalpha-/IL-10, IFN-gamma/IL-10, and IL-12p40/IL-10 decreased after addition of PC (P < 0.05). The results demonstrate favorable effects of PC on regulatory cytokines relative to inflammatory cytokines that might contribute to reduction of intestinal inflammation.

Animals↗

Abundance of mRNA of growth hormone receptor and insulin-like growth factors-1 and -2 in duodenal and colonic biopsies of dogs with chronic enteropathies*.

Repair processes of the inflamed intestine are very important for dissolution of chronic enteropathies (CE). Therefore, we examined the mRNA abundance of growth hormone receptor (GHR), insulin-like growth factors (IGF)-1 and -2 in duodenal and colonic biopsies of dogs with CE such as food-responsive diarrhoea (FRD) and inflammatory bowel disease (IBD) before and after treatment as compared with each other and healthy dogs. A clinical score (Canine IBD Activity Index = CIBDAI) was applied to judge the severity of CE. Biopsies of duodenum and colon from client-owned dogs with CE were sampled before (FRD(bef), n = 5; IBD(bef), n = 5) and after treatment (FRD(aft), n = 5; IBD(aft), n = 5). Intestinal control samples were available from a homogenous control population (n = 15; C). Intestinal samples were homogenized, total RNA was extracted, reverse transcribed and analysed by real-time polymerase chain reaction to measure mRNA levels of GHR, IGF-1 and IGF-2. Results were normalized with glyceraldehyde phosphate dehydrogenase as housekeeping gene. The CIBDAI decreased during the treatment period in FRD and IBD (P < 0.01). In duodenum, GHR mRNA levels were higher in all groups than in C (P < 0.001). Duodenal IGF-1 mRNA levels in FRD(aft) and IBD(aft) tended to be higher than in C (P < 0.1). The IGF-2 mRNA abundance in FRD(aft) was higher than in C (P < 0.05) in duodenum. In colon, mRNA levels of IGF-1 in IBD(aft) were higher than in FRD(aft) (P < 0.05) and levels differed between IBD(aft) and C (P < 0.05). In conclusion, mRNA levels of GHR, IGF-1 and IGF-2 in the gastrointestinal tract were increased during CE when compared with gastrointestinally healthy dogs. The data suggest that GHR, IGF-1 and IGF-2 are involved in gastrointestinal repair processes.

Animals↗

[Chronic intestinal diseases in the dog: a review].

The most commonly encountered chronic enteropathies in dogs are inflammatory bowel disease (IBD), food allergies, and small intestinal bacterial overgrowth. Recent research in the field of immunopathogenesis of IBD and food allergy in human beings have made available new therapeutic options with immunomodulatory drugs. However, the mechanisms involved in the pathogenesis of canine IBD and food allergy have not been elucidated so far. Further studies focusing on the immunological dysregulation in the mucosa as well as clinical trials with new therapeutic modalities are needed to improve our knowledge and approach to these chronic diseases in dogs.

Animals↗

Glucagon-producing neuroendocrine tumour associated with hypoaminoacidaemia and skin lesions.

A nine-year-old neutered female crossbred Bernese mountain dog was diagnosed with superficial necrolytic dermatitis and a glucagon-producing islet cell tumour. Laboratory findings included hyperglucagonaemia and hypoaminoacidaemia. The dog was euthanased because of progression of the disease, and necropsy revealed liver metastases of a neuroendocrine carcinoma with immunohistochemical expression of glucagon and somatostatin. This report represents a case of canine glucagonoma syndrome; the previously reported cases in dogs are also briefly described.

Adenoma, Islet Cell↗

Partial protection by vaccination with recombinant feline immunodeficiency virus surface glycoproteins.

In an effort to induce a strong immune response that might protect against feline immunodeficiency virus (FIV) challenge infection, three groups of five specified pathogen-free (spf) cats each were immunized subcutaneously with different FIV antigen preparations. Immunizations were done at weeks 0, 2, and 4 with 100 microg of recombinant SU from an FIV Zurich 2 (FIV Z2) strain expressed by E. coli (group 1) or the baculovirus expression system (groups 2 and 3) adsorbed on aluminum hydroxyde and administered with QS-21 (groups 1 and 2) or Freund's adjuvant together with the recombinant nucleocapsid protein (protein NC) of rabies virus (group 3). Protein NC was described to act as an exogenous superantigen. Group 3 cats demonstrated the highest detectable antibody response to the vaccine antigen as determined by ELISA and Western blot analysis. All immunized cats together with seven control animals were challenged with 20 CID50 of cat lymphocyte-grown FIV Z2 3 weeks following the last immunization. Whereas virus was readily recovered from peripheral blood lymphocytes of seven of seven nonvaccinated control cats following this challenge dose, virus was not recovered from two cats of groups 1 and 2. All cats in groups 2 and 3 showed a provirus load significantly decreased to 3% of that of controls up to week 8 after challenge infection. Eleven of 15 vaccinated cats and 5 of 7 control cats developed virus-neutralizing antibodies by week 8 after challenge infection. The two cats negative on virus isolation remained seronegative, developed no detectable virus-neutralizing activities, but were repeatedly positive in provirus PCR. Moreover, starting at week 1 after challenge, both cats showed the lowest provirus load in their respective groups. These results indicate that immunization with recombinant FIV SU in conjunction with appropriate adjuvants may lead to partial protection against FIV challenge infection.

Adjuvants, Immunologic↗

The role of in vitro-induced lymphocyte apoptosis in feline immunodeficiency virus infection: correlation with different markers of disease progression.

Human immunodeficiency virus infection is characterized by a progressive decline in the number of peripheral blood CD4(+) T lymphocytes, which finally leads to AIDS. This T-cell decline correlates with the degree of in vitro-induced lymphocyte apoptosis. However, such a correlation has not yet been described in feline AIDS, caused by feline immunodeficiency virus (FIV) infection. We therefore investigated the intensity of in vitro-induced apoptosis in peripheral blood lymphocytes from cats experimentally infected with a Swiss isolate of FIV for 1 year and for 6 years and from a number of long-term FIV-infected cats which were coinfected with feline leukemia virus. Purified peripheral blood lymphocytes were either cultured overnight under nonstimulating conditions or stimulated with phytohemagglutinin and interleukin-2 for 60 h. Under stimulating conditions, the isolates from the infected cats showed significantly higher relative counts of apoptotic cells than did those from noninfected controls (1-year-infected cats, P = 0.01; 6-year-infected cats, P = 0.006). The frequency of in vitro-induced apoptosis was inversely correlated with the CD4(+) cell count (P = 0. 002), bright CD8(+) cell count (P = 0.009), and CD4/CD8 ratio (P = 0. 01) and directly correlated with the percentage of bright major histocompatibility complex class II-positive peripheral blood lymphocytes (P = 0.004). However, we found no correlation between in vitro-induced apoptosis and the viral load in serum samples. Coinfection with feline leukemia virus enhanced the degree of in vitro-induced apoptosis compared with that in FIV monoinfected cats. We concluded that the degree of in vitro-induced apoptosis was closely related to FIV-mediated T-cell depletion and lymphocyte activation and could be used as an additional marker for disease progression in FIV infection.

Animals↗

Flow cytometric detection of activation-induced cell death (apoptosis) in peripheral blood lymphocyte subpopulations from healthy cats.

Human peripheral blood lymphocytes (PBLs) from healthy individuals are resistant to in vitro-induced apoptosis, but activated human lymphocytes can readily undergo apoptosis. The activation of human lymphocytes is accompanied by the upregulation of a cell surface antigen, the major histocompatibility complex (MHC) class II-antigen. Only a minority of PBLs are usually MHC class II-antigen-positive in healthy humans. In contrast, in healthy cats the majority of feline PBLs are MHC class II-antigen-positive. We have, therefore, investigated the sensitivity of feline peripheral blood lymphocytes obtained from specified pathogen free (SPF) cats to the induction of apoptosis. Feline PBLs from SPF cats (n = 16) and human PBLs from healthy donors (n = 2) were isolated. After short-term culture, cells were examined for the presence of fragmented DNA as a result of apoptosis by a DNA agarose gel electrophoresis method and for the presence of DNA double strand breaks by in situ 3' end labeling. In addition, relative DNA content per cell was flow cytometrically determined using propidium iodide (PI) or 7-actinomycin-D (7-AAD) and apoptotic cells were identified on the basis of a reduced DNA content. Cell surface antigens and cellular DNA were analyzed simultaneously by dual-color flow cytometric analyses in order to study lymphocyte subsets. Single- and dual-color analysis revealed that, in contrast to human lymphocytes, feline lymphocytes rapidly underwent apoptosis when cultured overnight in medium. Furthermore, the majority of apoptotic cells was found within the MHC II-positive cell subject.

Animals↗

[Quantification of proviral FIV DNA using competitive PCR].

Quantification of provirus copies is important in the context of different biological questions. The most reliable approach for DNA quantification is a PCR based on coamplification of two templates of similar length, the target sequence and the reference template, sharing the same primer recognition sequences. During the amplification, the two templates compete for the same primer set (competitive PCR, or cPCR) AND consequently amplify at the same rate independently of the number of cycles. The amplified products can be distingushed by their different lengths. After densitometrical analysis, the proviral copy number of experimentally feline immunodeficiency virus infected cats could be calculated, since a known amount of reference template was used. The method described here proved to be very sensitive (10 copies for the competitor-DNA) and was used to quantitate the proviral load during several experiments in which the influence of periodical immunestimulations and the effect of vaccines on the virus load was studied.

Animals↗

Pharmacokinetics and clinical efficacy of cyclosporine treatment of dogs with steroid-refractory inflammatory bowel disease.

The usual treatment of dogs with inflammatory bowel disease (IBD) consists of administration of immunosuppressive doses of steroids. However, some dogs are refractory to steroid treatment and pose a significant challenge to the veterinarian. Because cyclosporine A (cyA) has been shown to be effective in steroid-resistant IBD in humans, the purpose of this study was to investigate the pharmacokinetics and clinical efficacy of PO cyA treatment in dogs with steroid-refractory IBD (n = 14). All dogs were treated with cyA 5 mg/kg PO q24h for a period of 10 weeks. A clinical activity score was assigned to assess severity of clinical signs before and after treatment. The total number of infiltrating lymphocytes and T cells in duodenal biopsies were assessed before and after treatment in 9 dogs. In addition, serum concentration of cyA was measured in 8 dogs over a 24-hour period. Pharmacokinetic profiles in dogs with IBD were similar to those of healthy dogs. Improvement of clinical signs was observed in 12 of 14 dogs with IBD. Median clinical activity score after treatment with cyA was significantly reduced from a median score of 9 to a median score of 5 (P = 0.001). T cell numbers in duodenal biopsies were significantly decreased after treatment from a median +/- 95% range in the villous region of 28 (19-30) cells/10,000 microm2 before versus 7 (0-10)/10,000 microm2 after treatment, P = 0.01; and from a median +/- 95% range number in the crypt region of 15 (6-23) cells/10,000 microm2 before versus 4 (0-9)/10,000 microm2 after treatment, P = 0.02, implying T cell lysis as a possible mechanism of action. In conclusion, based on this small study, cyA appears to be an effective alternative drug in dogs with IBD that are refractory to immunosuppressive doses of steroids.

Adrenal Cortex Hormones↗