Flow cytometric evaluation of disseminated intravascular coagulation in a canine endotoxemia model

Sepsis is associated with substantial morbidity and mortality in dogs. Alterations in hemostasis by systemic inflammation play an important role in the pathophysiology of sepsis. To evaluate the functional hemostatic changes in sepsis, we evaluated coagulation profiles and flow cytometric measurement of P-selectin (CD62P) expression on platelets, as well as platelet-leukocyte aggregation from a lipopolysaccharide (LPS)-induced endotoxemia model in dogs (n = 7). A sublethal dose of LPS [1 mg/kg body weight (BW)] induced thrombocytopenia and increased activated partial thromboplastin time (aPTT), prothrombin time (PT), and D-dimer concentrations. Flow cytometry analysis showed a significant increase in P-selectin expression on platelets between 1 and 24 h of a total 48 h of the experiment. In addition, platelet-leukocyte aggregation was significantly increased in the early stage of endotoxemia (at 1 and < 6 h for platelet-monocyte aggregation and at 3 h for platelet-neutrophil aggregation). Our results suggest that CD62P expression on platelets and platelet-leukocyte aggregation, as measured by flow cytometry, can be useful biomarkers of disseminated intravascular coagulation (DIC) in canine sepsis. These functional changes contribute to our understanding of the pathophysiology of hemostasis in endotoxemia.     

Flow cytometric analysis of canine umbilical cord blood lymphocytes

Lymphocyte subsets in canine umbilical cord blood were flow cytometrically analyzed and compared with those of the dams' peripheral blood. The proportion of CD3+ T lymphocytes, CD21+CD3- B lymphocytes, and CD3-CD21- non-T non-B lymphocytes in umbilical cord blood was 52.9%, 30.4%, and 16.7%, respectively. T lymphocyte/B lymphocyte ratio was significantly lower in the umbilical cord blood than in the dams' peripheral blood (2.1 +/- 1.4 versus 11.0 +/- 8.1, P < 0.001). In contrast, CD4+ lymphocyte/CD8+ lymphocyte ratio was significantly higher in the umbilical cord blood than in the dams' peripheral blood (7.6 +/- 2.2 versus 1.8 +/- 0.6, P<0.001). These findings clarified the phenotypic characters of canine umbilical cord blood lymphocytes.     

Development of multidrug resistance in a canine lymphoma cell line

New multidrug resistant cell lines developed from the canine B cell lymphoma cell line (GL-1) were characterized in terms of chemosensitivity to some antineoplastics and P-glycoprotein (Pgp) expression. GL-1 was continuously exposed to a culture medium containing gradually increasing levels of doxorubicin and the cells that could grow in the presence of doxorubicin were obtained. Chemosensitivity of these cells to various antineoplastics were investigated with or without verapamil, which reversed Pgp-mediated drug resistance. The expression of Pgp on the cells was also examined by Western blot analysis. As a result, three kinds of resistant cell lines, designated as GL-DOX60, 300, and 4000 were obtained. These cell lines showed stable proliferation in the medium containing 60, 300, and 4000 ng/ml, respectively. These cells were much more resistant to vincristine than doxorubicin. This resistance was strongly reversed by the presence of verapamil. On the other hand, cisplatin was effective enough in killing these derived cells. In the Western Blot analysis, some bands that reacted to the anti-human Pgp monoclonal antibodies were observed in GL-DOX4000. The cells derived from GL-1 have multidrug resistance potential mediated by canine Pgp. The cells produced in this experimental trial are considered to be useful models for various investigations on canine multidrug resistance.     

Flow cytometric evaluation of bound IgG on erythrocytes of anaemic dogs

The detection of red blood cell (RBC)-bound immunoglobulins in case of anaemia with the direct agglutination test (DAT or Coombs test) has been reported to be of low sensitivity. We therefore tested the applicability of flow cytometry for the detection of canine IgG on RBC using two different IgG-specific secondary reagents: goat-anti-dog IgG (GalphaD-IgG) and rabbit-anti-dog IgG (RalphaD-IgG). Membrane staining RBC samples were performed at 4 degrees C. Comparisons of agglutination test at 37 degrees C and 4 degrees C showed, that binding of the secondary antibodies at 4 degrees C was more sensitive compared to agglutination at 37 degrees C and the two antisera differed considerable in their agglutination activity. Binding of GalphaD-IgG and RalphaD-IgG to RBC of healthy dogs (n=15) was low and mean fluorescence intensities were taken to calculate thresholds above which RBC of patients were judged positive. As in agglutination tests, both secondary antisera displayed considerable differences (concentration-dependent binding and histogram profiles) after flow cytometric analysis. Using flow cytometry, with GalphaD-IgG 8 of 17 agglutination-negative patients were positive and RalphaD-IgG was positive with 3 of 3 agglutination-negative RBC samples. Thus, flow cytometric analysis of proved to be a sensitive technique, detecting RBC-bound canine IgG of DAT-negative patients. The results of both techniques, however, are significantly influenced by the used IgG-specific polyclonal reagents.     

Flow cytometric analysis of canine colonic mucosal lymphocytes from endoscopically obtained biopsy specimens

OBJECTIVE: To validate use of canine colonic biopsy specimens obtained via endoscopy as a source of mucosal lymphocytes (ML) for flow cytometric analysis. SAMPLE POPULATION: Mucosal biopsy specimens from 10 adult dogs. PROCEDURE: Mucosal lymphocyte subsets obtained from excised colon were compared with ML subsets obtained from biopsy specimens obtained by use of an endoscopic forceps (6 dogs). Endoscopic colonic biopsy specimens from 4 other dogs were used to define whether obtained ML were predominantly of intraepithelial or lamina propria origin. Mucosal lymphocytes were isolated and labeled, using commercially available monoclonal antibodies directed against canine cell surface antigens. Lymphocyte subsets (cytotoxic or helper T cells; B cells) were determined by use of flow cytometric analysis. RESULTS: A large number of viable ML was obtained after dissociation of the colonic epithelium from excised colon (45.5 + 21.5 X 10(6)) and endoscopic (7.2+/-3.4 X 10(6)) biopsy specimens. Lymphocyte subsets obtained with both methods were identical for each dog and consisted predominantly of intraepithelial lymphocytes, with some lymphocytes from the lamina propria. Collagenase digestion of excised colon also yielded a large number of viable lymphocytes from the lamina propria (56.7+/-20.4 X 10(6)), but collagenase digestion of endoscopic biopsy specimens was less rewarding. CONCLUSION AND CLINICAL RELEVANCE: A representative sample of viable intraepithelial ML is obtainable from endoscopic biopsy specimens. Flow cytometric analysis, a minimally invasive technique, can be used to study ML of client-owned animals.     

Flow cytometric enumeration of reticulocyte in the peripheral blood from canine infected with Babesia gibsoni

Peripheral blood samples from dogs infected with Babesia gibsoni were analyzed by a flow cytometer for the percentage of reticulocytes after staining with a membrane-permeable fluorochrome, thiazole orange. Though thiazole orange has been reported to stain human reticulocytes and Plasmodium-infected erythrocytes, number of positive cells determined by the flow cytometry did not include that of erythrocytes infected with Babesia gibsoni. Analysis of 51 samples revealed a correlation coefficient of 0.96 as compared to the conventional determination by light microscopy. Separation of reticulocytes from Babesia gibsoni-infected erythrocytes by flow cytometry with or without the stain remained unresolved.     

Effects of dietary fish oil and vitamin E supplementation on canine lymphocyte proliferation evaluated using a flow cytometric technique

Lymphocyte proliferation and peripheral blood mononuclear cell (PBMC) production of PGE(2) were assayed in 15 healthy dogs fed a basal diet supplemented with either sunflower oil (Group Sunflower oil), sunflower oil and menhaden fish oil (Group Fish oil), or sunflower oil and menhaden fish oil plus alpha-tocopherol acetate for 12 weeks (Group Fish oil + E). Lymphocyte proliferation was determined by a flow cytometric technique utilizing the fluorochrome carboxyfluorescein diacetate succinimidyl ester (CFSE). The PBMC supernatant PGE(2) concentration was assayed using a competitive enzyme-linked immunoassay. Group Fish oil had a significant decrease in lymphocyte proliferation at week 12. PBMC production of PGE(2) was decreased in all three groups but only significantly reduced in groups receiving fish oil supplementation. Based on these results, this level of fish oil supplementation appears to suppress the lymphoproliferative response in healthy, young dogs but this response can be attenuated by high levels of dietary vitamin E supplementation. Furthermore, fish oil-induced reduction in lymphocyte proliferation appears to manifest through a PGE(2)-independent mechanism and is not associated with increased lipid peroxidation.     

Induction of chemoresistance in a cultured canine cell line by retroviral transduction of the canine multidrug resistance 1 gene

OBJECTIVE: To induce chemoresistance in a normal canine cell line through the transduction of the canine multidrug resistance 1 gene (mdr1). SAMPLE POPULATION: Madin-Darby canine kidney (MDCK) epithelial cell line. PROCEDURES: The full-length canine mdr1 cDNA clone isolated in our laboratory was inserted into a Moloney murine leukemia virus-based vector to construct the retroviral vector, pLNC-cMDR1. After retroviral transduction of pLNC-cMDR1 into MDCK cells, the expression and function of the P-glycoprotein, a product of mdr1, were assessed by immunoblotting, measurement of rhodamine123 (Rh123) retention, and drug sensitivity assays. RESULTS: P-glycoprotein was strongly expressed in cells transduced with pLNC-cMDR1. This P-glycoprotein was fully functional, as demonstrated by the decreased Rh123 retention and the increased resistance to chemotherapeutic drugs. Measured as 50% inhibitory concentrations, resistance increased 59 times to vincristine and 25 times to doxorubicin in MDCK cells after transduction of pLNC-cMDR1. CONCLUSIONS AND CLINICAL RELEVANCE: Transduction of canine mdr1 is an effective method for inducing chemoresistance in normal canine cells. This system may be applicable to the induction of drug resistance in hematopoietic cells.     

Flow cytometric analysis of lymphocyte subset kinetics in Bali cattle experimentally infected with Jembrana disease virus

Jembrana disease virus (JDV) is an unusual bovine lentivirus that causes an acute and sometimes fatal disease after a short incubation period in Bali cattle (Bos javanicus). The pathological changes occur primarily in lymphoid tissues, which feature proliferating lymphoblastoid-like cells predominantly throughout parafollicular (T-cell) areas, and atrophy of follicles (B-cell) areas. Five Bali cattle were experimentally infected with JDV and all developed typical clinical signs of Jembrana disease characterised by a transient febrile response, enlargement of superficial lymph nodes and a significant leukopenia. Flow cytometric analysis of PBMC during the acute (febrile) disease phase showed that the reduced number of lymphocytes was due to a significant decrease in both the proportion and absolute numbers of CD4(+) T cells, but not CD8(+) T-cells or CD21(+) B-cells. At the end of the febrile phase, total numbers of both CD8(+) T-cells and CD21(+) B-cells increased significantly, while CD4(+) T-cell numbers remained below normal values, resulting in a significantly reduced CD4(+):CD8(+) ratio. We speculate that the persistent depletion of CD4(+) T cells following JDV infection, through lack of CD4(+) T cell help to B cells, may explain the lack of production of JDV-specific antibodies for several weeks after recovery despite an increase in CD21(+) B cell numbers. Further, our previous data showing that IgG(+) plasma cells are targets for JDV infection, correlated with our current data demonstrating an increase in CD8(+) T cell numbers, supports the suggestion that anti-viral cytotoxic T cell or other cell-mediated immune responses may be critical in the recovery process, although this remains to be formally demonstrated for JDV.     

The canine lymphocyte: effect of streptolysin O on the proliferative response of canine lymphocytes

The effects of Streptolysin O (SLO) on canine peripheral blood lymphocytes were studied using the lymphocyte blastogenesis test (LBT). Canine lymphocytes stimulated with SLO produced a response that was similar to the response obtained with the commonly used phytomitogens: phytohemagglutinin (PHA), concanavalin A (CON A) and pokeweed mitogen (PWM). When SLO was added to any of the phytomitogens and incubated with canine lymphocytes, an additive or stimulatory response was obtained. However, mixing the phytomitogens in any combination did not produce a similar additive or stimulatory response. The results were interpreted to mean that in the canine system, the binding of SLO to lymphocytes does not sterically interfere with receptors for PHA, CON A, or PWM. Additionally, SLO may stimulate a population of lymphocytes that is distinct from that stimulated by the phytomitogens. Moreover, it would appear that the phytomitogens probably stimulate the same or an overlapping population of lymphocytes. Experiments using enriched lymphoid cell populations were used to characterize the lymphocytes stimulated by phytomitogens and SLO. Lipopolysaccharides from two different bacteria were unable to cause a significant lymphoproliferative response.     

Flow cytometric assessment of ethylene glycol monoethyl ether on spermatogenesis in rats

The effects of ethylene glycol monoethyl ether (EGEE) on testicular cell populations in rats were investigated by a flow cytometric method. Rats were administered by gavage with EGEE at the various doses of 0 (saline alone), 100, 200, 400, and 800 mg/kg body weight/day for 4 weeks. The treatment of EGEE caused decreases in the weight of testis and epididymis and in the number of testicular cells. Histopathologically, exfoliation of germ cells into the tubular lumen was observed at the doses of above 200 mg/kg. The treatment of EGEE at the dose of 400 mg/kg caused moderate testicular degeneration. A significant depletion of haploid cells and a disproportionate ratio of diploid and tetraploid cells were observed as determined by flow cytometric analysis. These results indicate that the toxic effect of EGEE on the male reproductive system may be strongly associated with the disproportion of testicular germ cells.     

Computed tomographic evaluation of the canine intercondylar notch in normal and cruciate deficient stifles.

In the human and veterinary orthopaedic literature it has been implied that intercondylar notch stenosis is a mechanical factor in cranial cruciate ligament rupture and intraarticular graft failure. The patients in this study were classified as normal (32), unilateral cruciate rupture (23), or bilateral cruciate rupture (17). The dogs were placed under general anaesthesia and both stifles were scanned via computed tomography (CT) as previously described. Three CT slices at predetermined levels were evaluated within the notch. Measurements included opening notch angle, notch width and height, condyle width, and notch width index (notch width/condyle width) at two different heights within the notch. Intercondylar notch measurements at the most cranial extent were significantly more narrow in unilateral and bilaterally affected stifles when compared to the normal population. Significant differences were noted in the opening notch angle (ONA), notch width index (NWI), NWI at two thirds notch height (NWI2/3), and tibial slope index (TSI). No significant differences were noted between unilateral and bilateral affected stifles. Increased mechanical contact of the cranial cruciate ligament with a stenotic intercondylar notch may predispose the ligament to mechanical wear and structural weakening. Intercondylar notch measurements have been used as a tool to predict the risk of anterior cruciate ligament injury in young human athletes, and to assess the risk factors for intra-articular graft replacements. Our findings may be useful in developing similar predictive models using stifle CT scans.     

Cellular characterization of multidrug resistance P-glycoprotein, alpha fetoprotein, and neovascular endothelium-associated antigens in canine hepatocellular carcinoma and cirrhotic liver

P-glycoprotein (P-gp), which is encoded by the multidrug resistance gene (MDR-1); alpha fetoprotein (AFP); and vascular endothelium-associated antigens are well-known markers for human and canine hepatic diseases. We obtained liver tissues from 5 dogs with hepatocellular carcinoma (HCC) and 12 dogs with cirrhosis, and we performed histopathologic and immunohistochemical evaluations using anti-P-gp, anti-AFP, anti-CD31, and anti-CD34 antibodies. P-gp was expressed at higher levels in HCC than in cirrhotic livers ( P < .01), and was most commonly localized in biliary canaliculi and small ductuli. AFP was localized mainly in the cytoplasm in HCC ( P < .01) and in a few cases of cirrhosis. In both HCC and cirrhosis, the AFP-positive cells were morphologically similar to normal hepatocytes and showed an even cytoplasmic distribution of AFP. The endothelial markers CD31 and CD34 were used to investigate vascular distribution. CD31 was expressed strongly in the portal area and parenchyma in HCC, but it was rarely observed in the parenchyma in cirrhosis. CD34 expression could not be detected in both HCC and cirrhosis. This study constitutes the first comprehensive study of P-gp, AFP, and endothelial markers in canine HCC and cirrhosis. The importance of these markers in HCC and cirrhosis in dogs was demonstrated and provides a more accurate basis for a definitive diagnosis of HCC and cirrhosis in dogs.     

Effects of amiodarone on myocardial performance in normal canine hearts and canine hearts with infarcts

The effects of IV administered amiodarone, a class-III antiarrhythmic agent, on myocardial contractility, early myocardial relaxation, and hemodynamic variables were evaluated in normal canine hearts and those with infarcts. In the normal canine heart, amiodarone had important, but relatively mild, depressant effects on left ventricular contractility (assessed by maximal positive first derivative of left ventricular pressure (+dP/dtmax) and maximal elastance (Emax)) and heart rate when given IV at a dose of 10 mg/kg of body weight. An effect on contractility or active relaxation (assessed by maximal negative first derivative of left ventricular pressure (-dP/dtmax) and the time constant of isovolumic pressure decrease) was not identified with smaller doses. Myocardial infarction itself caused a predictable and marked depressant effect on myocardial contractility, as indicated by decreases in +dP/dtmax, ejection fraction, Emax, and -dP/dtmax, and elevation in end diastolic pressure. Additional depressive effects on contractility and active relaxation resulted when 10 mg of amiodarone/kg was administered to dogs with myocardial infarction and these effects were sufficient to worsen acute myocardial infarction-induced heart failure. Significant changes attributable to heart rate alone could not be identified. On the basis of our findings, we suggest that amiodarone administered IV should be used with caution in dogs with compromised ventricular function.     

Immunohistochemical evaluation of surfactant proteins and lymphocyte phenotypes in the lungs of cattle with natural tuberculosis

The aim of the present study was to evaluate the immunohistochemical expression of pulmonary surfactant proteins (SP-A, SP-B, SP-C) and lymphocytic phenotypes in the lungs of 12 cattle with natural tuberculosis. Grossly, the disease-affected cattle revealed numerous granulomas in the lung lobes. Histopathological examination found multiple lung granulomas with typical cellular elements. Type II pneumocytes with adenomatous proliferation around the granulomas were strongly immunopositive for SP-A and SP-B compared to normal type II cells. Clara cells showed also cytoplasmic immunopositivity for these surfactant proteins. Positive immunolabelling for proSP-C was detected exclusively in the normal and proliferative type II pneumocytes, and the reaction was marked in the perinuclear area of the cells. CD3⁺ T and CD79αcy⁺ B lymphocytes were predominantly localized in the fibrotic capsule margin of advanced granulomas, in greater numbers than in the early granulomas. In conclusion, the study found that type II pneumocytes proliferated highly and surrounded the tuberculous granulomas in the lungs, that hyperplastic type II pneumocytes synthesized and secreted larger amounts of surfactant proteins than the normal type II cells, and that SP-A might have played an important role in host defence against the mycobacterial agents. Additionally, the presence of high numbers of CD3⁺ T cells throughout the granulomas confirmed the dominance of a cellular immune response in cattle tuberculosis.     

The growth profiles of three types of canine distemper virus on Vero cells expressing canine signaling lymphocyte activation molecule

To know growth profiles of canine distemper virus (CDV) on Vero cells stably expressing canine signaling lymphocyte activation molecule (Vero-DogSLAMtag; Vero-DST cells), the propagation of three strains of CDV was tested in Vero-DST cells in comparison with parental Vero cells. Strain MD77 could grow well in both cell lines, but demonstrated no syncytium formation or indistinguishable rounding cytopathic effects (CPE) in Vero cells. Strains Onderstepoort and KDK-1 also grew well in Vero-DST cells with apparent syncytium CPE, while they grew less or no efficiently, respectively, in Vero cells. All three CDV strains demonstrated the peak titers, in Vero-DST cells before reaching to an extensive CPE and drastic decrease of titers at/after full CPE. Immunohistochemistry revealed that viral antigens of all CDV strains were found exclusively in the syncytia in Vero-DST cells, while in Vero cells, viral antigen was identified in their single cells for strain MD77 but none for other strains. Thus, every strain of CDV could grow well in Vero-DST cells and behaved differently against Vero cells. These results would be of practical value for workers of CDV because 1) In Vero-DST cells, by observation of distinct syncytium CPE, the highest titer or the best growth of virus could be identified; 2) In Vero cells, various CDV strains could be readily classified after propagation in Vero-DST cells.     

The effect of different isolation procedures on canine leucocyte populations and on lectin-induced lymphocyte proliferation

Proliferation assays performed on peripheral blood mononuclear cells (PBMC) are commonly used in experimental and clinical immunology. A prerequisite for an in vitro assay is the ability to obtain relatively pure populations of mononuclear cells from whole blood, as contaminating polymorphonuclear cells may affect the proliferation of lymphocytes. Purification of canine leucocytes from whole blood is associated with difficulties in obtaining pure lymphocytes in high yields. The aim of this study was to optimize the lymphocyte purification from canine whole blood in terms of total cell recovery and purity, while not influencing the proliferation capacity of the isolated cells. To acquire optimal isolation of canine lymphocytes several density gradient media of different densities and osmolalities were examined. For optimal phagocyte removal, pre-treatment of whole blood with carbonyl iron/arabic gum and/or adherence to fibrinogen pre-coated polystyrene tissue flasks were examined. Lectin-induced proliferation was used as measurement of cell activity of the obtained cell fractions after the different separation procedures. Canine blood pre-treated with carbonyl iron/arabic gum followed by density gradient centrifugation with medium 'G' (density: 1.079 g/cm(3), osmolality: 256 mOsm) and adherence to pre-coated polystyrene tissue flask obtained the best PBMC cultures with a median lymphocyte purity of 88% and a median yield of recovered lymphocytes of 54%. This culture also resulted in the highest proliferation and subsequently the highest stimulation index upon lectin stimulation.     

Flow cytometric analysis of chicken NK activity and its use on the effect of restraint stress

Immune system is organized by the influence of both neural and endocrine systems. NK activity plays an important role in the innate immunity. In this study, we observed the effects of restraint stress on chicken peripheral blood NK activity. Viability of FITC-labeled RP9 was measured with PI after treatment with the effector cells. Chicken peripheral blood CD8alpha+ cells expressed strong cytotoxic activity, in contrast to thrombocytes, while peripheral blood CD3+ CD8alpha+ cells and CD4+ cells had little cytotoxic activity. Con A supernatant enhanced the cytotoxic activity of CD8alpha+ cells. Therefore, it is considered that these cytotoxic activities measured by flow cytometry (FCM) analysis are NK activity. When chickens were exposed to restraint stress, the levels of serum corticosterone increased transiently over a short period of time while the NK activity decreased. The decreased NK activity, however, did not recover to the intact levels for a long time, even once the serum corticosterone levels had recovered. These data indicate that chicken NK activity is able to be measured by flow cytometric analysis and that restraint stress causes severe damage to the chicken NK activity.     

An Investigation of the Trypsin Digest Test on apparently normal canine faeces

Abstract— —Faecal samples from 72 animals with no disease or history of disease pertaining to the pancreas, were examined for presence of trypsin by means of the Trypsin Digest Test. Each faecal sample was examined microscopically to determine the state of digestion of muscle fibres and the presence or absence of free fat globules. The amount of trypsin found in each sample was expressed as a dilution or titre. The highest titre demonstrated was 1:1280. The lowest was nil. 9.7 per cent of faecal samples produced a titre of nil and 62.5 per cent of faecal samples produced a titre below 1:100. All the faecal samples had a normal appearance and consistency and all showed that adequate digestion had taken place judging from microscopical examination. It was concluded that the trypsin digest titre in itself was of limited value. It should always be considered along with microscopical examination of the faeces when relevant information regarding the pancreatic exocrine secretion might be gained. However, other factors can effect the test and. so repeated tests ought to be done and the results of these tests considered cautiously in conjunction with the clinical findings and the possible influence of these other factors. Résumé— —Des échantillons de fécés provenant dc soixante douze animaux en bonne santé et sans antécédents pathologiques de rapportant au pancréas ont été examinés pour rechercher la présence de trypsine à Faide de l'Epreuve de détermination de la trypsine du tractus digestif. Chaque échantillon de fécés a été examiné au microscope pour apprécier l'état de digestion des fibres musculaires ainsi que la présence ou l'absence de globules de graisse. Le taux de trypsine trouve pour chaque échantillon a été exprimé par sa dilution ou son titre. Le titre le plus haut était 1/1.280 et le plus bas de zéro 9.7 pour cent des échantillons de féces ne contenaient pas de trypsine et 62.5 pour cent avaient un titre au dessous de 1/100. Tous les échantillons de fécés avaient une apparence et une consistance normales et pour tous il a été montré que la digestion appréciée à l'aide de l'examen microscopique paraissait normale. Il a été conclu que le titre de trypsine digestive présentait en lui-même une valeur limitée. Il devra toujours être apprécié par rapport à l'examen microscopique des fécés lorsque l'on doit obtenir des renseignements sur la secrétion exocrine du pancréas. Cependant, d'autres facteurs peuvent modifier l'épreuve et ainsi on devrait répéter les tests et leurs résultats devraient être interprétés avec précaution compte tenu des données de la clinique et de l'influence possible de ces autres facteurs. Zusammenfassung— —Fäkalproben von 72 Tieren, die frei von Krankheiten oder Krankheits-geschichten in bezug auf das Pankreas waren, wurden mittels des Trypsin Digest Tract auf die Anwesenheit von Trypsin untersucht. Jede Fäkalprobe wurde einer mikroskopischen Untersuchung unterzogen, um den Verdauungsgrad von Muskelfasern und die Anwesenheit oder das Fehlen von freien Fetttröpfchen festzustellen. Die in jeder Probe gefundene Trypsinmenge wurde als Verdünnung oder Titer angegeben. Der hochste festgestellte Titer war 1: 1280. Der niedrigste betrug null. 9,7% der Fäkalproben ergaben den Titer null und 62,5% der Fäkalproben ergaben einen Titer unter 1: 100. Alle Fäkalproben zeigten normales Aussehen und normale Konsistenz sowie, dass—nach der mikroskopischen Untersuchung zu urteilen—eine ausreichende Verdauung stattgefunden hatte. Es wurde der Schluss gezogen, dass der Trypsinverdauungstiter allein von begrenztem Wert ist. Er muss stets zugleich mit dem mikroskopischen Fäkaluntersuchungsergebnis betrachtet werden, wenn brauchbare Informationen hinsichtlich der exokrinen Pankreassekretion erhalten werden sollen. Andere Faktoren können jedoch den Test beeinflussen, und so sollten wiederholte Unter-suchungen durchgeführt und deren Ergebnisse sorgfältig in Verbindung mit den klinischen Befunden und dem möglichen Einfluss dieser anderen Faktoren betrachtet werden.