Increase In Total Leukocyte Count Research Articles

Hematological alterations after acute exposure to hyperbaric oxygen in rats.

1. Acute exposure to hyperbaric oxygen (HBO) is associated with a significant increase in haematocrit which returns to the control level after 24h of recovery in room air. In this study we report changes in blood viscosity in Sprague-Dawley rats after acute exposure to HBO. 2. The rats were divided into three groups: a control group included rats not exposed to HBO (CON), a group studied immediately after acute exposure to HBO at 283.7 kPa for 6h (HBO), and a group allowed to recover for 24h in room air after HBO exposure (REC). 3. The viscosity of the whole blood, plasma and red blood cells (RBC) suspension was measured in the three groups. A significant increase in whole blood viscosity was detected in HBO and REC groups compared with CON (P < 0.05), but no changes in the viscosity of the plasma or RBC suspension were noted. 4. A significant decrease in oxygen delivery index was found in the REC group compared with the CON and HBO groups (P < 0.05). 5. In a subgroup of rats, several blood parameters known to influence blood viscosity were evaluated. A significant increase in plasma colloid oncotic pressure was noted in HBO rats compared with CON (P < 0.01). A marked increase in platelet count and fibrinogen concentration was detected in HBO and REC rats compared with CON (P < 0.05). Furthermore, a significant increase in total leukocytic count was noticed in REC group compared with CON and HBO (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of milbemycin oxime in chemoprophylaxis of dirofilariasis in cats

Summary Although cats are less susceptible to infection with Dirofilaria immitis than are dogs, the possibility of severe consequences from infection or adulticidal treatment renders preventive treatment a desirable alternative in endemic areas. To evaluate the efficacy of milbemycin oxime as a chemoprophylactic agent in cats, 48 cats were inoculated with infective D immitis larvae. Single oral treatment with 2.3 mg of milbemycin oxime (0.5 to 0.9 mg/kg of body weight) at 30 or 60 days after inoculation with infective larvae gave strong but incomplete protection. Treatment at 60, as well as 90, days after inoculation with infective larvae was completely effective in preventing development of infection. A control group of inoculated, but untreated, cats was monitored biweekly for hematologic changes and for changes in parasite-specific serum antigen and antibody concentrations. Pronounced increases in total leukocyte counts and eosinophil numbers were associated with the estimated time of in vivo molting from fourth- to fifth-stage larvae. Antibody reactivity correlated with infection status, but serum antigen concentrations through 161 days after inoculation were undetectable.

Maintenance Treatment of Patients With Myelodysplastic Syndromes Using Recombinant Human Granulocyte Colony-Stimulating Factor

Myelodysplastic syndromes (MDS) are characterized by chronic refractory cytopenias resulting in increased risk of infection, bleeding, and conversion to acute leukemia. In an effort to improve these cytopenias we have treated 18 patients over a 6- to 8-week period with increasing daily subcutaneous doses of recombinant human granulocyte colony-stimulating factor (G-CSF). Sixteen patients responded with improvement in neutrophil counts. On cessation of treatment these counts returned to baseline values over a 2- to 4-week period. To maintain these improved blood counts 11 patients were treated with G-CSF for more prolonged periods. Ten patients again responded with an increase in total leukocyte counts (1.6- to 6.4-fold) and absolute neutrophil counts (ANC) (3.6- to 16.3-fold), with responses persisting for 3 to 16 months. A significantly decreased risk of developing bacterial infections was noted during periods with ANC greater than 1,500/mm3 as compared with periods of time with ANC less than 1,500/mm3. Two anemic patients had a greater than 20% rise in hematocrit over the study period, and 2 additional patients had a decrease in red blood cell transfusion requirements during G-CSF treatment. Bone marrow myeloid maturation improved in 7 of 9 maintenance phase patients. Three patients progressed to acute myeloid leukemia during treatment. The drug was generally well-tolerated and no severe toxicities were noted. These data demonstrated that G-CSF administered to MDS patients by daily subcutaneous administration was well-tolerated and effective in causing persistent improvement of the neutrophil levels and marrow myeloid maturation. These effects were associated with a decreased risk of infection and, in some patients, with decreased red blood cell transfusion requirements.

Maintenance treatment of patients with myelodysplastic syndromes using recombinant human granulocyte colony-stimulating factor

Myelodysplastic syndromes (MDS) are characterized by chronic refractory cytopenias resulting in increased risk of infection, bleeding, and conversion to acute leukemia. In an effort to improve these cytopenias we have treated 18 patients over a 6- to 8-week period with increasing daily subcutaneous doses of recombinant human granulocyte colony- stimulating factor (G-CSF). Sixteen patients responded with improvement in neutrophil counts. On cessation of treatment these counts returned to baseline values over a 2- to 4-week period. To maintain these improved blood counts 11 patients were treated with G-CSF for more prolonged periods. Ten patients again responded with an increase in total leukocyte counts (1.6- to 6.4-fold) and absolute neutrophil counts (ANC) (3.6- to 16.3-fold), with responses persisting for 3 to 16 months. A significantly decreased risk of developing bacterial infections was noted during periods with ANC greater than 1,500/mm3 as compared with periods of time with ANC less than 1,500/mm3. Two anemic patients had a greater than 20% rise in hematocrit over the study period, and 2 additional patients had a decrease in red blood cell transfusion requirements during G-CSF treatment. Bone marrow myeloid maturation improved in 7 of 9 maintenance phase patients. Three patients progressed to acute myeloid leukemia during treatment. The drug was generally well-tolerated and no severe toxicities were noted. These data demonstrated that G-CSF administered to MDS patients by daily subcutaneous administration was well-tolerated and effective in causing persistent improvement of the neutrophil levels and marrow myeloid maturation. These effects were associated with a decreased risk of infection and, in some patients, with decreased red blood cell transfusion requirements.

Electrochemical Treatment of Cancer. IV

The effects on hematological parameters in peripheral blood was measured by electronic cell counting after electrochemical treatment (n = 11), after electrochemical treatment with concomitant intraneoplastic injection of the chemotherapeutic agent doxorubicin (Adriamycin) (n = 13), and after electrochemical treatment with concomitant intravenous infusion of Adriamycin (n = 2). After treatment, a reduction in lymphocyte count (p less than 0.01) and an increase in total leukocyte count (p less than 0.01) was observed. There was a trend that during treatment the platelet count was reduced.

Effect of glucocorticoids on cows suspected of subclinical infection withM. paratuberculosis

Glucocorticoids were administered to 10 heifers suspected of subclinical infection with Mycobacterium paratuberculosis. Three animals remained untreated. M. paratuberculosis was isolated from the internal organs of 2 animals after this treatment but not from any of the control group. Delayed type hypersensitivity and lymphocyte reactivity towards Johnin and purified protein derivates of M. avium and M. bovis were depressed. A sharp increase in total leucocyte count, due to an increase in neutrophil numbers, occurred. In the three untreated animals these parameters did not change during the experiment. A decrease of specific immunological reactivity towards M. paratuberculosis occurred, but not to such an extent that clinical disease developed.

Leukocytosis of exercise: role of cardiac output and catecholamines

The effect of propranolol (5 mg iv) on the leukocytosis of exercise was studied in seven normal young males. Leukocyte counts, plasma norepinephrine (NE), epinephrine (E), and cardiac output were measured at rest and in the steady state of several submaximal work loads when subjects exercised on a cycle ergometer. The results in control experiments were compared with those obtained on a different day with propranolol. Propranolol decreased heart rate at all work loads (P less than 0.001) but had no effect on the increase in cardiac output at increasing work loads. Plasma NE and E levels were similar at rest and in exercise in control and propranolol studies. There was no effect of propranolol on the increase in leukocyte counts with increasing work loads. Although propranolol did not affect the increase in total leukocyte count, the increase in lymphocyte count at higher work loads was less with propranolol. We conclude that the demargination of leukocytes from the pulmonary circulation in exercise is probably a mechanical effect of the increase in cardiac output. However, we have not excluded a contribution from a humoral event that would decrease the adherence of leukocytes to endothelium during exercise. The smaller increase in lymphocytes at higher work loads in the presence of propranolol suggests that catecholamines affect the lymphocyte count over and above their effect on cardiac output.

A longitudinal study of leucocyte numbers and mitogenesis during the last ten weeks of human pregnancy

Leucocyte numbers rose consistently in normal primigravid women sampled repeatedly during the last ten weeks of pregnancy. The increase in total leucocyte count was significant from 35 weeks gestation to delivery and was directly related to an increase in neutrophils, while mononuclear cell numbers remained unaltered. In addition to the pregnancy associated neutrophilia there was a further increase in neutrophil counts at delivery. Using whole blood and purified leucocytes in culture, it was confirmed that pregnancy plasma contains suppressor factors which inhibit mitogenesis with PHA or Con A. There was no significant change in individual women's whole blood mitogenic response at any time during the sampling period except at delivery when there was a significant decrease. Culture of washed cells from pregnant women in non-pregnancy plasma restored their mitogenic response to levels found in non-pregnant control women, except at delivery when there was evidence of a cell-associated impairment of function. Purified leucocyte cultures from individual women sampled repeatedly from 30 weeks gestation to delivery gave variable responses although it was still possible to identify pregnancy-related plasma suppressor factors and delivery-associated impairment of leucocyte function in vitro.

Epidemic typhus infection in cynomolgus monkeys (Macaca fascicularis).

A nonhuman primate model of clinical Rickettsia prowazekii infections was developed in cynomolgus monkeys (Macaca fascicularis). Monkeys infected intravenously with 10(7) plaque-forming units developed clinical signs of illness and pathological changes characteristic of epidemic typhus infection in humans. Increases in total leukocyte counts, serum alkaline phosphatase, blood urea nitrogen, and serum glutamic pyruvate transaminase values were observed. Microscopic examination revealed typical typhus nodules in the brains of two monkeys that died. These data indicated that the cynomolgus monkey is a suitable model for study of the pathogenesis of epidemic typhus infection and may prove valuable in the evaluation of candidate R. prowazekii vaccines.