Blood Viscosity of Two Mammalian Hibernators: Spermophilus tridecemlineatus and Tamias striatus

During a 2-year study on the relationships between immature Dermacentor variabilis and their small-mammal hosts near Birds Hill, Manitoba, 739 captures of 427 mammals were examined for ticks. Captures represented 11 mammal species: Clethrionomys gapperi, Lepus americanus, Microtus pennsylvanicus, Mus musculus, Peromyscus maniculatus, Sorex cinereus, Spermophilus franklinii, Spermophilus tridecemlineatus, Tamias striatus, Tamiasciurus hudsonicus, and Zapus hudsonius. Clethrionomys gapperi, M. pennsylvanicus, P. maniculatus, S. franklinii, and Z. hudsonius were most frequently encountered and, with the exception of S. franklinii, infested with larvae and nymphs. Clethrionomys gapperi were most frequently infested by D. variabilis and produced 42.6% and 60.5% of larvae collected in 1979 and 1980, respectively, and over 85% of all nymphs. Peak larval infestation occurred between the last week of May and the middle of June; that for nymphs occurred in July in both 1979 and 1980. Dermacentor variabilis appeared to have a 2-year life cycle in Manitoba. Larvae were spatially aggregated during both years and aggregates were located in different areas of the plots each year. Nymphs were less aggregated than larvae. The distribution of nymphs overlapped that of larvae each year and occupied a greater area on the plots.

Download Full-text

The Effects of KBT-3022, a New Anti-platelet Agent, on Hemorheological Properties in Guinea Pigs

Thrombosis and Haemostasis ◽

10.1055/s-0038-1653735 ◽

1995 ◽

Vol 73 (01) ◽

pp. 118-121 ◽

Cited By ~ 6

Author(s):

Noriko Yamamoto ◽

Koichi Yokota ◽

Akira Yamashita ◽

Minoru Oda

Keyword(s):

Shear Stress ◽

Blood Viscosity ◽

Guinea Pigs ◽

Direct Action ◽

Plasma Viscosity ◽

Fibrinogen Concentration ◽

Anti Platelet Agent ◽

Blood Filterability ◽

2,3 Dpg ◽

Rbc Deformability

SummaryUsing guinea pigs, a study was conducted on the effects of KBT-3022, a new anti-platelet agent, on hemorheological properties in various tests including blood filterability, blood viscosity, shear stress-induced red blood cell (RBC) deformability and contents of ATP and 2,3-diphosphoglycerate (2,3-DPG). Oral administration of KBT-3022 at 1 and 10 mg/kg significantly increased blood filterability, and significantly reduced blood viscosity at 10 mg/kg without changing the hematocrit, plasma fibrinogen concentration or plasma viscosity. KBT-3022 (10 mg/kg, p.o.) improved RBC deformability in response to shear stress, which was evoked by passing the blood through a thin tube. This dose of KBT-3022 also increased the contents of ATP and 2,3-DPG in RBC. These findings indicate that KBT-3022 may reduce blood viscosity as a sequel to improvement of RBC deformability through direct action on RBC. The increase in the intracellular levels of ATP and 2,3-DPG was considered to be involved in this improvement of hemorheological properties. These hemorheological effects of KBT-3022 appear to be promising for the treatment of patients with ischemic vascular disease.

Download Full-text

Blood Viscosity and Platelet Aggregation in Male and Female Patients with Transient Ischaemic Attacks (TIA)

10.1055/s-0038-1665805 ◽

1979 ◽

Author(s):

G. Palareti ◽

M. Poggi ◽

G. Fortunato ◽

S. Coccheri

Keyword(s):

Platelet Aggregation ◽

Blood Viscosity ◽

Indirect Evidence ◽

Vascular Lesions ◽

Transient Ischaemic Attacks ◽

Group A ◽

Circulating Platelet Aggregates ◽

Male Patients ◽

Group B ◽

Almost All

A series of 40 patients with TIA (25 males and 15 females) was thoroughly investigated by means of angiography and computerized tomography, and divided into a group (A) of 15 “sine materia”, and a group (B) of 25 with direct or indirect evidence of vascular occlusive or stenotic changes. Blood viscosity at 230 sec-1 37° was cp 4.2 ± 0.3 in the controls, cp 4.7 ± 0.7 in all patients (p < 0.05) cp 4.98 ± 0.7 in all male patients (p < 0.01 versus male controls), and cp 4.75 ± 0.8 in group B (p < 0.02). Haematocrit and Fibrinogen were also significantly increased in all male patients and in group B. Circulating platelet aggregates (CPA) were increased in 40% of the patients. Almost all patients with elevated CPA were males, with a slight prevalence in group B. Changes in blood viscosity parameters and in platelet aggregation in TIA patients were therefore related both to evidence of vascular lesions, and to sex, since they were found to prevail in male patients of both groups.

Download Full-text

Viscosity and Red Cell Deformity in Arterial Disease

10.1055/s-0038-1665789 ◽

1979 ◽

Author(s):

G Cella ◽

H de Haas ◽

M Rampling ◽

V Kakkar

Keyword(s):

Vascular Disease ◽

Blood Viscosity ◽

Whole Blood ◽

Arterial Disease ◽

Plasma Viscosity ◽

Control Group ◽

Fibrinogen Concentration ◽

Red Cell ◽

Whole Blood Viscosity ◽

Significant Difference

Haemorrheological factors have been shown to be affected in many kings of vascular disease. The present study was undertaken to correlate these factors in normal subjects and patients suffering from peripheral arterial disease. Twenty-two patients were investigated; they had moderate or severe intermittent claudication, extent of disease being confirmed by aorto-arteriography and ankle-systolic pressure studies. Twenty-five controls with no symptoms or signs of arterial disease were selected with comparable age and sex distribution. Whole blood viscosity was measured at shear rates of 230 secs-1 and 23 secs-lat 37°c using a Wells Brookfield cone plate microvisco meter. Plasma viscosity was also measured in an identical manner. Erythrocyte flexibility was measured by centrifuge technique and fibrinogen concentration as well as haematocrit by standard techniques. The fibrinogen concentration appeared to be the only significant parameter; the mean concentration in patients with peripheral vascular disease of 463 ± 73mg/l00ml in the control group ( < 0.05). Although whole blood viscosity was high in patients, when corrected to a common haematocrit, there was no significant difference between patients and controls. The same megative correlation was found for plasma viscosity. The red cell flexibility was found to be increased in patients as compared to the control group, but this effect appeared to be simply proportional to the fibrinogen concentration.

Download Full-text

Abnormal Haemostasis and Blood Viscosity in Malignant Hypertension

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661190 ◽

1984 ◽

Vol 52 (03) ◽

pp. 253-255 ◽

Cited By ~ 11

Author(s):

C Isles ◽

G D O Lowe ◽

B M Rankin ◽

C D Forbes ◽

N Lucie ◽

...

Keyword(s):

Blood Pressure ◽

Blood Viscosity ◽

Renal Damage ◽

Antithrombin Iii ◽

Plasma Viscosity ◽

Malignant Hypertension ◽

Fibrin Deposition ◽

Group 3 ◽

Group 2 ◽

Group 1

SummaryWe have previously shown abnormalities of haemostasis suggestive of intravascular coagulation in patients with malignant hypertension, a condition associated with retinopathy and renal fibrin deposition. To determine whether such abnormalities are specific to malignant hypertension, we have measured several haemostatic and haemorheological variables in 18 patients with malignant hypertension (Group 1), 18 matched healthy controls (Group 2), and 18 patients with non-malignant hypertension (Group 3) matched for renal pathology, blood pressure and serum creatinine with Group 1. Both Groups 1 and 3 had increased mean levels of fibrinogen, factor VIIIc, beta-thrombo- globulin, plasma viscosity and blood viscosity (corrected for haematocrit); and decreased mean levels of haematocrit, antithrombin III and platelet count. Mean levels of fast antiplasmin and alpha2-macroglobulin were elevated in Group 1 but not in Group 3. We conclude that most blood abnormalities are not specific to malignant hypertension; are also present in patients with non-malignant hypertension who have similar levels of blood pressure and renal damage; and might result from renal damage as well as promoting further renal damage by enhancing fibrin deposition. However increased levels of fibrinolytic inhibitors in malignant hypertension merit further investigation in relation to removal of renal fibrin.

Download Full-text