Clinical interpretation of leukocyte responses

Advanced maternal age impacts physiologic adaptations to pregnancy in vervet monkeys

The trend to delay pregnancy in the USA has resulted in the number of advanced maternal age (AMA) pregnancies to also increase. In humans, AMA is associated with a variety of pregnancy-related pathologies such as preeclampsia (PE). While AMA is known to be a factor which contributes to the development of pregnancy-induced diseases, the molecular and cellular mechanisms giving rise to this phenomenon are still very limited. This is due in part to lack of a preclinical model which has physiologic relevance to human pregnancy while also allowing control of environmental and genetic variability inherent in human studies. To determine potential physiologic relevance of the vervet/African green monkey (Chlorocebus aethiops sabaeus) as a preclinical model to study the effects of AMA on adaptations to pregnancy, thirteen age-diverse pregnant vervet monkeys (3-16 years old) were utilized to measure third trimester blood pressure (BP), complete blood count, iron measurements, and hormone levels. Significant associations were observed between third trimester diastolic BP and maternal age. Furthermore, the presence of leukocytosis with enhanced circulating neutrophils was observed in AMA mothers compared to younger mothers. Moreover, we observed a negative relationship between maternal age and estradiol, progesterone, and cortisol levels. Finally, offspring born to AMA mothers displayed a postnatal growth retardation phenotype. These studies demonstrate physiologic impairment in the adaptation to pregnancy in AMA vervet/African green monkeys. Our data indicate that the vervet/African green monkey may serve as a useful preclinical model and tool for deciphering pathological mediators of maternal disease in AMA pregnancy.

Evaluation of short-term outcomes and potential risk factors for death and intestinal dehiscence following full-thickness large intestinal incisions in dogs

OBJECTIVE

To determine complication rates for dogs in which full-thickness large intestinal incisions were performed, assess potential risk factors for death during hospitalization and for intestinal dehiscence following these surgeries, and report short-term mortality rates for these patients.

ANIMALS

90 dogs.

PROCEDURES

Medical records of 4 veterinary referral hospitals were reviewed to identify dogs that underwent large intestinal surgery requiring full-thickness incisions. Signalment, history, clinicopathologic data, medical treatments, surgical procedures, complications, and outcomes were recorded. Descriptive statistics were calculated; data were analyzed for association with survival to discharge (with logistic regression analysis) and postoperative intestinal dehiscence (with Fisher exact or Wilcoxon rank sum tests).

RESULTS

Overall 7-day postoperative intestinal dehiscence and mortality rates were 9 of 90 (10%) and 15 of 90 (17%). Dogs with preoperative anorexia, hypoglycemia, or neutrophils with toxic changes and those that received preoperative antimicrobial treatment had greater odds of death than did dogs without these findings. Preexisting colon trauma or dehiscence, preexisting peritonitis, administration of blood products, administration of > 2 classes of antimicrobials, positive microbial culture results for a surgical sample, and open abdominal management of peritonitis after surgery were associated with development of intestinal dehiscence. Five of 9 dogs with intestinal dehiscence died or were euthanized.

CONCLUSIONS AND CLINICAL RELEVANCE

Factors associated with failure to survive to discharge were considered suggestive of sepsis. Results suggested the dehiscence rate for full-thickness large intestinal incisions may not be as high as previously reported, but several factors may influence this outcome and larger, longer-term studies are needed to confirm these findings.

Behavioural and physiological indicators of shelter dogs' welfare: reflections on the no-kill policy on free-ranging dogs in Italy revisited on the basis of 15 years of implementation

The Italian National Law 281 of 1991 forbids the euthanatization of free-ranging dogs, unless they have an incurable illness or are proved to be dangerous. Without neglecting the undeniable benefits of the "no-kill" policy, nevertheless it has brought about a chronic overpopulation in shelters and, as a result, higher costs of management and welfare problems since some dogs remain in the shelter for life. In 2004-2008, the Istituto Zooprofilattico Sperimentale of the Lazio and Tuscany regions carried out a survey in the Lazio Region to verify the effects of the Italian National Law 281/91 on free-ranging dog management following 15 years from its implementation. One of the aims of the study was an assessment of the welfare of dogs in a shelter sample (8 shelters out of 47 censused in the Lazio Region). 97 mixed-breed dogs were selected, their behaviour was studied and a blood sample was taken for each dog in order to determine the individual blood concentration of cortisol and the amount of oxidative damage (level of dRoms), as well as the amount of antioxidants to cope with it. Moreover, the total leukocyte count (leukogram) was accomplished. We ran general backward stepwise regression models using "level of antioxidant", "level of dRoms" and "level of serum cortisol" as dependent variables respectively. The results showed that the most important variable that improved the level of welfare of dogs consisted in having the opportunity to regularly go out of the cage for a walk, whereas other variables like gender, size of the cage (small, medium, large), being alone in the cage, and being neutered/entire, had no significant effect on the physiological indicators of welfare. Dogs that enjoyed the regular walk had a higher total antioxidant capacity, and performed a lower frequency of displacing activities and stereotyped behaviour. Moreover, oxidative stress parameters seem to be indicators well matched with behavioural indicators of stress. Thus, for the first time, markers of oxidative status are utilised for the welfare evaluation in the domestic dog. Furthermore, the results of this paper give some suggestion about how small steps can help to improve shelters and, furthermore, this paper intends to solicit the debate on the no-kill policy.

Prognostic usefulness of blood leukocyte changes in canine parvoviral enteritis

Background: Despite treatment, many dogs still die of complications related to canine parvoviral (CPV) enteritis. Effective prognostication would be beneficial in managing this disease.

Hypothesis: We hypothesize that the occurrence of leukocytopenias at admission and at 24 and 48 hours after admission, and changes in absolute leukocyte counts over time, could be used to predict outcome.

Animals: Sixty‐two puppies with confirmed CPV.

Methods: A prospective study was performed. CBC was performed daily until discharge or death (in which case a postmortem examination was performed).

Results: Of the nonsurvivors (10/62; 16%), 9 died because of complications of the disease and 1 was euthanized because of a poor prognosis. There was a statistical significant difference in the occurrence of leukocytopenias between groups at 24 and 48 hours postadmission. The survivors showed a significant increase over time in certain leukocyte types (specifically lymphocytes) compared with values at admission. The positive predictive value for survivors was high. Nonsurvivors had marked thymic and lymphoid atrophy and marked bone marrow hypocellularity.

Conclusion: An accurate prognosis could be obtained at 24 hours after admission by evaluating the change in total leukocyte, band neutrophil, lymphocyte, monocyte, and eosinophil counts.

Effects of an S6 Strain of Mycoplasma gallisepticum Inoculation Before Beginning of Lay on the Leukocytic Characteristics of Commercial Layers

A clinical study was conducted on commercial layers housed in biological isolation units, within which exogenous stress factors potentially affecting bird performance were minimized. This set-up was devised in order to assess how a pre-lay inoculation of S6 strain Mycoplasma gallisepticum affects the leukocytic properties of laying chickens. Previous studies have demonstrated relative decreases in lymphocyte and relative increases in heterophil percentages in birds infected with other strains of Mycoplasma gallisepticum. However, current results showed that the differential percentages of lymphocytes were decreased, whereas those of heterophils were increased, in both sham-inoculated control birds and birds inoculated with S6 Mycoplasma gallisepticum between 19 and 26 wk of age. This study clearly shows that a pre-lay inoculation of S6 Mycoplasma gallisepticum alone had no apparent effect on the leukocyte profile of commercial layers housed in biological isolation units.

The neutrophil. Function, disorders, and testing

Normal neutrophil function requires the cooperation and coordination of many cellular activities within the neutrophil and cells of the vascular system. The free flowing neutrophil begins the process by "rolling" along the vessel wall. This first step in migration is mediated by selectins on the surface of neutrophils, platelets, and endothelial cells. Subsequent firm adhesion requires the collaboration of neutrophil integrins and membrane-expressed cellular adhesion molecules. The activated neutrophil also changes shape from a sphere to an elongated motile cell by the assembly of actin filaments. At the inflammatory focus the neutrophil may encounter material to be ingested and killed. The ingestion process is mediated by the same receptors that stimulate firm adherence to the vessel wall. The ingestion process stimulates the formation of active NADPH oxidase, which is critical for the formation of superoxide and subsequent components of the killing mechanism. The process of normal neutrophil function is complex and multifaceted, but luckily, defects in this system are extremely rare. Patients with persistent and recurrent infections should be carefully evaluated for underlying disease before primary neutrophil dysfunction is pursued.

Neutropenia with a probable hereditary basis in Border Collies

This paper documents a disease of Border Collies characterised by chronic neutropenia which probably resulted in recurrent bacterial infections manifesting as osteomyelitis and sometimes gastroenteritis. The neutropenia occurred despite hyperplasia of the myeloid cells in the bone marrow and a shift to the right in myeloid cell maturation. The underlying defect is currently unknown but may result from the inability of neutrophils to escape from the bone marrow into the peripheral circulation. Necrosis and new bone formation commonly involved the metaphyseal regions of long bones. Other findings included a fasting hypercholesterolaemia and the occasional presence of nucleated red blood cells in circulation, despite a non-regenerative anaemia. An autosomal recessive mode of inheritance is suspected. This condition has some features of a rare human disease called myelokathexis which is also believed to have in autosomal recessive mode of inheritance.

Feline immunodeficiency virus infection. Clinicopathologic findings in 90 naturally occurring cases

In 90 cats with naturally occurring feline immunodeficiency virus (FIV) infection, the clinicopathologic changes seen at the time of first diagnosis of FIV infection included lymphopenia (29%), neutrophilia (27%), monocytosis (23%), anemia (18%), leukocytosis (13%), leukopenia (13%), neutropenia (11%), hyperproteinemia (38%), and hyperglobulinemia (25%). Forty-nine (54%) of the cats showed multiple hematologic abnormalities, and a further 24 (17%) had a single abnormality. The most consistent changes in serum protein electrophoretic patterns were increases in the concentrations of alpha 2 globulin and gammaglobulin subfractions. Although there is no established system for staging the degree of immunosuppression in cats infected with FIV, cytopenias appeared to be more common in cats with advanced clinical signs of disease.

Laboratory abnormalities in patients with cancer

In this problem-oriented review of abnormalities associated with cancer, we have emphasized distinctive diagnostic points related to pathogenesis for each condition and outlined how the approach to management is determined by pathogenesis. For abnormalities of the complete blood count, it is important to distinguish between abnormalities directly related to marrow malignancy and abnormalities associated with extramarrow malignancy. Hemopoietic tumors consist of developmentally deficient blood cells produced by a clonal population of malignant stem cells. Tumors infiltrating marrow cause overcrowding in the limited marrow microenviroment. Extramarrow malignancies cause blood abnormalities, but the potential for normal marrow function is present. Abnormalities of blood cells secondary to therapy are usually clearly identified by consideration of clinical history. The initial differential diagnosis for hypercalcemia is malignancy. An aggressive diagnostic approach may be needed to identify the neoplasm, and therapy should incorporate measures to prevent renal failure. Hypoproteinemia and hyperproteinemia may be caused by neoplasia. Monoclonal gammopathies should be identified and may be associated with hyperviscosity syndrome. Hypoglycemia in the adult animal is most frequently caused by insulin-secreting tumors, but it has also been associated with hepatic and other tumors. Increased blood urea nitrogen, creatinine, lipase, amylase, and liver enzyme activities may also be caused by malignancy. Inadequate urine concentrating ability may be caused by hypercalcemia or malignancy-associated renal insufficiency. Hematuria in older animals is suggestive of urinary tract neoplasia. Exfoliated tumor cells may be identified in the urine sediment of these patients.