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Granulocyte functions in sheep treated with 1-24 ACTH
No full textGRANULOCYTE FUNCTIONS IN SHEEP TREATED WITH 1-24ACTH
Paltrinieri S., Comazzi S., Sartorelli P., Agnes F., Istituto di Patologia Generale Veterinaria, via Celoria 10, Milano, Italy
In order to verify if the increase in infectious diseases during stress could be due to an impairment in granulocyte functions, the different steps of the phagocytic process of neutrophil granulocytes (PMN) taken from sheep treated with 6,5 μg/Kg/b.w. of 1-24 ACTH (Synachten, Ciba) were investigated in vitro and the result compared with those obtained from untreated control sheep. PMN functions were tested before (T0) and 1 (T1), 2 (T2), 24 (T3) and 48 hours (T4) after 1,24 ACTH admnistration.
The effectiveness of 1-24 ACTH administration was indicated by a neutrophilic leukocytosis and an increase in cortisol levels in treated animals Chemotaxis, measured using a modified Boyden chamber against omologous zymosan activated serum (ZAS) and recombinant human interleukin-8 (IL-8) showed a more homogeneous response to chemoattractants compared to controls. The ability of ingestion was not influenced by 1-24 ACTH administration: either in treated or in untreated sheep, in fact, 24 hours after the basal sampling was detectable an increase in phagocytosis of both inhert latex polystyrene beads and opsonized fluorescent yeasts. Adherence and respiratory burst were measured simultaneously in microtiter plates using a spectrophotometer to detect the superoxide production and the amount of acid phosphatase released from lysed adherent PMNs. Adhesive properties of neutrophils from treated sheep were increased when the highest cortisol levels were detectable, while the superoxide production, that increased at T2 in control sheep, did not show any increase in 1-24 ACTH treated sheep.
The results presented here indicate that some steps of the phagocytic process are influenced in stressed animals. The “in vitro” increase of adherence might suggest an increased efficiency of the non-specific immune system, but the same finding has been interpreted by Arber et al. (1991) as a decreased “in vivo” ability of diapedesis throughout endothelial cells. In contrast, the depressed respiratory burst, compared to controls, might indicate a depressed bactericidal activity.
Although stress “in vivo” has a more complex pattern than a simple administration of ACTH, the impairment of sheep PMN functions detected after 1-24 ACTH administration may contribute to the increased susceptibility to infectious diseases in stressed animals.
Reference;
Arber et al. (1991), Actaa haematologica, 86:20-2
Performances of cytology and flow cytometry to predict diagnosis of canine lymphoma and subtypes
Full text linkCytology plays a central role in the diagnostic algorythm for canine lymphoma. Canine lymphoma is a great
candidate to be sampled via fine needle aspiratebiopsy since it is mainly a multicentric disease, involvement of
superficial nodes is frequent and the architectural histological pattern is diffuse in most cases. Accuracy may be
implemented by ancillary techniques such as flow cytometry (FC) and immunocytochemistry (ICC). However, the
diagnostic performances of cytology alone with or without some ancillary techniques is not completely elucidated
in veterinary medicine. In a recent metanalysis in humans, cytology alone showed a sensitivity of 87% and a
specificity of 97% in the identification of lymphoma vs non-lymphoma. This values increased by adding FC or ICC.
However, no data on the performances in identifying specific lymphoma subtypes via cytology were described.
In dogs the current classifications used for canine lymphoma are the updated Kiel and the WHO classifications. The
updated Kiel classification is mainly a cytological scheme based on morphological aspects and it demonstrated a
fair agreement among readers in a previous study. In contrast, WHO is mainly based on histological criteria but
previous papers suggest a possible correlation between these two diagnostic schemes. We recently evaluated
the diagnostic performances and repeatibility of cytology alone for 1) predicting lymphoma vs non-lymphoma; 2)
predicting grade and subtype and 3) predicting WHO subtype.
Cytology showed good performances (sensitivity 92.6%, specificity 89.4%) and repeatibilities in predicting
lymphoma vs non-lymphoma. As expected this values decrease for the evaluation of grade and phenotype, and
for WHO subtype. The major diagnostic challenges were the identification of the grade of B cell lymphomas
and the identification of the immunophenotype for high grade lymphomas with many B cell lymphoma cases
minsinterpreted as T cell.
Flow cytometry may easily help to definitely diagnose the immunophenotype thus solving this issue. On the
other side it may also be useful to discriminate between high and low grade lymphomas by possibly evaluating
the percentage of KI67 positive cells. Further studies on the diagnostic performance of cytology + FC for canine
lymphoma are needed and currently in process
Evaluation of RBC metabolism to improve the clinico-pathological diagnosis : some cases in dogs
No full textUtilizzo della soritolo deidrogenasi (SDH) nella diagnosi di laboratorio delle epatopatie del cavallo: studio su 350 casi
No full text
“In vitro” evaluation of granulocyte functions in healthy dogs and in dogs with neutrophilic leukocytosis
No full text“IN VITRO” EVALUATION OF GRANULOCYTE FUNCTIONS IN HEALTHY DOGS AND IN DOGS WITH NEUTROPHILIC LEUKOCYTOSIS
Paltrinieri S., Comazzi S., Sartorelli P., Mussinelli F.
Istituto di Patologia Generale Veterinaria – Milano - Italy
Extensive evaluation of the different steps of the phagocytosis in neutrophils (PMNs) are not available in healthy dogs nor in dogs with inflammatory diseases. In this work we designed a panel of tests to investigate all the steps of phagocytosis in the same animal. Among the techniques reported in literature those performable with small amount of blood were choosen, to test dogs with spontaneous diseases, on which the isolation of large numbers of cells is often difficult.
6 control dogs (group 1) and 6 with neutrophilic leukocytosis (group 2), due to different diseases (post surgical infections, pyotorax, uroperitoneum, enteritis) were tested. PMNs were isolated from 3 ml of EDTA-preserved blood using discontinous gradient sedimentation technique with Percoll ( = 1.092/1.071). Chemotaxis was evaluated in a modified Boyden chamber against recombinant human interleukin 8 (rhIL-8), and with both the leading front and the cell count methods. Opsonized fluoresceinated yeasts were used to evaluate the uptake ability, expressing the results as percentage of phagocytic PMNs and as phagocytic index (PI = nr of ingested yeasts/100 PMNs). Adherence was measured in microtiter plates, by spectrophotometric evaluation of the release of acid phosphatase after washing of non adherent cells; before washing, superoxide production was evaluated measuring the cytocrhome C reduction: plastic contact and phorbol myristate acetate (PMA) were used as non-specific and specific activators of adherence and respiratory burst.
Percoll isolation yeld a pure PMNs population, but the recovery rate of group 2 dogs was significantly lower (P<0.05) than in controls. The rhIL-8 is a good chemoattractant of canine PMNs and the leading front method should be used. Group 2 dogs had an higher response to rhIL-8 (P<0.01) than the controls (P<0.05). Higher values of the percentage of phagocytic PMNs (P<0.01) and of the PI (P<0.01) was detected in group 2 dogs. Basal adherence was very variable among healthy dogs; plastic contact increased the adherence (P<0.05), while PMA did not. These findings were detected also in group 2 dogs, without differences with the controls. Basal superoxide production was always very low. PMA increased the respiratory burst of the controls (P<0.05) and not those of group 2 dogs, maybe due to the individual variations.
The selected tests allowed a simultaneous evaluation of the steps of phagocytosis in healthy dogs, although the individual variations in adherence and respiratory burst may suggest some modification of the method. In dogs with neutrophilia uptake ability and chemotaxis are increased,possibly due to pre-activation; the individual variations among these dogs may be due to the aetiology of the disease
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