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Biomedical subjects

R Lombardini

Publications and source records attributed to R Lombardini.

At least 37 records · Page 2Linked to original sources
PubMed1990

Blood rheology during induced ischaemia of the lower limbs.

The filterability rate of whole blood, the red and white blood cell sub-populations, and the erythrocyte and leucocyte count variations were studied during exercise in 20 male non-diabetic smokers, all with Stage II peripheral vascular disease (PVD), and 20 matched controls. A controlled ischaemia was induced using treadmill exercise. Blood samples were taken at rest, at the onset of calf pain and at haemodynamic recovery from peak exercise. Leucocytes were counted, separated using Ficoll-Hypaque into their sub-populations by centrifugation, and adherence to Petri dishes, re-suspended in buffer and filtered through 5 micron pore diameter filters. Whole blood filterability and the leucocyte count were significantly increased at the onset of calf pain. A significant increase was observed in the filterability of the monocyte sub-fraction and this persisted throughout the recovery period.

Blood Viscosity↗
PubMed1990

Stable angina pectoris and controlled ischemia: what causes the abnormalities in whole blood filterability?

The determinants of the altered whole blood filterability observed during coronary ischemia are still under discussion. Since no studies have been carried out to date on what exactly causes these alterations during the early stages of controlled ischemia in coronary heart disease, a model was set up using a bicycle ergometer test (with a 25 W increase every 2 minutes). Blood samples were taken from 48 stable angina pectoris patients and from a group of 28 matched controls before and immediately after exercise and 8 minutes later. Plasma viscosity, the filterability (through 5 microns diameter pore filters) of whole blood, erythrocytes, and polymorphonuclear and mononuclear leukocytes (separated by density gradient) were monitored. Alterations in whole blood filterability could be linked only to an impairment in polymorphonuclear cell filterability in those stable angina pectoris patients who reported chest pain and/or whose ST segment depression was greater than or equal to 2 mm.

Angina Pectoris↗
PubMed1990

Physical exercise and blood flow properties.

In 46 executive level managers at risk for cardiovascular disease, whole blood filterability through five micron pore Nuclepore filters was monitored using a constant flow positive pressure system before and after treadmill exercise and compared to our laboratory standard. Our results show regular exercise compensates not only for the potential damage risk factors represent but also for the physical stress provoked by vigorous exercise.

Blood Circulation↗
PubMed1990

Effects of ticlopidine on the neurologic outcome and the hemorheologic pattern in the postacute phase of ischemic stroke: a pilot study.

This double-blind pilot study observed the effects of a twenty-one day oral ticlopidine treatment (250 mg/twice daily) on the neurologic outcome and the hemorheologic pattern of 15 patients and 15 placebo-treated controls. Patients and controls (age range sixty-six to eighty-six years) were included in the study within twelve hours of the onset of ischemic stroke, confirmed clinically and by computerized tomography. Scores on Hachinski's Scale and the following hemorheologic parameters were monitored weekly for twenty-one days: fibrinogen levels, the whole blood, unfractionated white and red blood cell filterability rates (through 5-micron-pore-diameter filters using a constant-flow positive-pressure system), and the leukocyte count and activation (by microscopic observation). The results showed treatment with ticlopidine improved the neurologic outcome (Hachinski's Score +36%, p less than 0.03) slightly but significantly (p less than 0.001) increased the average values of the whole blood (+19%) and red cell (+17%) filterability rates and decreased fibrinogen levels (-17%).

Aged↗
PubMed1990

Reactive oxygen metabolites in peripheral arterial occlusive disease.

Plasma oxidant activity (marker of reactive oxygen metabolites) and the unfractionated leucocyte filterability rate (determined through 5 micron pore diameter Nuclepore filters, using a positive pressure system) were monitored in 15 stage II peripheral vascular disease (PVD) patients before and after ischaemia was induced by treadmill exercise (12 degrees slope/2 km/hour). Plasma oxidant activity increased (+ 115%) significantly (p less than 0.001) at the maximum walking time, correlating (r = 0.79) with a significant (p less than 0.001) impairment (+23%) in the unfractionated leucocyte filterability rate. At the transcutaneous oxygen pressure (tcPO2) half recovery time the plasma oxidant activity approached basal values but the unfractionated leucocyte filterability rate remained significantly (p less than 0.001) impaired (+16%). It returned to basal values at the full tcPO2 recovery time. These results show reactive oxygen metabolites are released during ischaemia of the lower limbs and are correlated with a significant impairment in the flow properties of leucocytes.

Arterial Occlusive Diseases↗
PubMed1989

[The behavior of leukocyte rheology in induced ischemia in peripheral arterial occlusive disease].

We studied the quantitative and qualitative behaviour of white blood cells (WBCs) at rest and after standard treadmill exercise in 20 male stage II peripheral vascular disease (PVD) patients, compared to 20 healthy matched controls. The aim of this study was to define the role of WBCs in PVD. The results confirm the WBC count was significantly increased in PVD patients. Surprisingly, however, the only rheological WBC variable which showed a significant variation during the ischaemic pain caused by treadmill exercise was the filterability of mononuclear leukocytes. This would seem to identify disturbances in mononuclear filter-ability, associated with ischaemic pain resulting from claudication, as a functional sign of PVD.

Aged↗
PubMed1989

[Infection and tissue ischemia: what role does the rheologic behavior of blood cells play?].

It is not clear how acute infection is associated with a subsequent ischaemic brain infarction. Infection may, in fact, cause changes in blood fluidity. Abnormalities in blood flow, particularly in white blood cell rheology, are known to be precipitating factors for ischaemic events. Therefore the rheological behaviour of the erythrocytes and the leukocytes were studied 30 days after the onset of acute bacterial infections in 30 patients and in a group of 50 controls (matched for sex, body mass index and cardiovascular risk factors). Our results show a significant impairment in the flow properties of the leukocytes in the patients compared to the controls, and indicate disturbances in leukocyte rheology might be considered an additional risk factor for ischaemic brain infarction when it occurs shortly after febrile infection.

Aged↗
PubMed1989

Leucocyte rheology in the early stages of ischaemic stroke.

Within 5 hours of the onset of ischaemic stroke the filterability patterns and the counts of the granulocyte, monocyte and lymphocyte subfractions were monitored. The results were compared to those of a healthy matched control group and to those of a matched group with cardiovascular risk factors. The granulocyte filterability rate was significantly impaired in the group at risk and even more so in the stroke group suggesting alterations in it may be a sign of latent ischaemia.

Aged↗
PubMed1989

Leucocyte rheology in controlled coronary ischaemia.

Since no studies have been carried out on the exact origin of the alterations in white blood cell rheology during the early stages of controlled ischaemia in coronary arterial disease, a model was set up using a cycle ergometer test (with a 25 watts increase every 2 minutes). Blood samples were taken (before and after exercise and again 8 minutes later at recovery) from 18 patients with stable angina pectoris and a group of 22 matched controls. The filterability (through 5 micrometer diameter pore filters) of the polymorphonuclear leucocyte sub-population (separated by density gradient), the monocyte and lymphocyte sub-fractions (separated by adhesion to Petri dishes) as well as leucocyte activation (observed under a light microscope) were monitored. Our results showed that the total leucocyte count in patients and controls rose after exercise and was accompanied by a differential shift from the polymorphonuclear to the lymphocyte cells. The polymorphonuclear filterability rate increased significantly in patients when compared to their basal values at rest, and to the controls after exercise (+ 19.58%; P less than 0.002 vs basal values at rest; + 18.72%; P less than 0.002 vs controls). This increase persisted throughout the recovery period (+ 19.86%; P less than 0.002 vs basal values; and + 23.52% P less than 0.001 vs controls), indicating that a reduced polymorphonuclear leucocyte filterability can be associated with the first signs of ischaemia.

Aged↗
PubMed1989

Correlation between clinical and laboratory findings when the whole blood filterability rate is modified by ticlopidine in the treatment of rheumatoid arthritis.

This double-blind study assessed the effects of oral ticlopidine versus placebo on whole blood filterability in two homogenous groups of 20 rheumatoid arthritis patients taking one NSAID. The patients' clinical progress was monitored to see if modifications in the whole blood filterability rate could be correlated with any improvement in the clinical picture. Our results showed treatment with ticlopidine significantly (p less than 0.01) improved both the ESR (-28%) and the whole blood filterability rate (-15%), pain (-24%), and morning stiffness (-28%). These clinical benefits correlated with improvement in the whole blood filterability rate. Clinical benefits may have resulted from improved perfusion and transport of NSAID to target tissues.

Adult↗
PubMed1989

Human leucocyte rheology and tissue ischaemia.

Reports suggest that white blood cells are involved in the development of tissue ischaemia. No studies on leucocyte rheology in the earliest stages of ischaemia exist. In 10 peripheral vascular disease (PVD) patients, 10 stable angina pectoris (SAP) patients and two groups of 10 matched controls leucocytes were separated by density and adherence into their granulocyte, lymphocyte and monocyte subpopulations. Blood samples were taken from the PVD group and respective controls before and after treadmill exercise (5 min 2 km-1 h-1, 12% slope) and from the SAP patients and controls before and after cycle ergometer test (25 W every 3 min). All the subpopulations were filtered through five micron diameter pore filters. Compared to controls, calf pain in the PVD patients was associated with an increase in monocyte filterability (P less than 0.01). ST depression in the SAP patients was linked to impaired granulocyte filterability (P less than 0.04). Therefore leucocyte rheology appears impaired in the earliest stages of ischaemia.

Angina Pectoris↗
PubMed1989

Leucocyte behaviour in controlled ischaemia of the calves.

Whole blood filterability and leucocyte behaviour (number, activation, and subfraction filterability rates) were monitored at the earliest stage of peripheral ischaemia in 18 patients with stage II peripheral occlusive arterial disease (PAOD) and 20 matched controls. A model of controlled ischaemia, using exercise to stress leg circulation, was set up and blood samples were taken before exercise, at the onset of calf pain, and at recovery from peak exercise. Leucocytes were counted, separated into their subfractions on a Ficoll-Hypaque density gradient and by adhesion to Petri dishes, and filtered in buffer (like the whole blood suspensions) through 5 microns pore diameter Nucleopore filters. Unfractionated white cells, separated under gravity, with pseudopodia or cytoplasmic irregularities were regarded as activated. The whole blood filterability rate was significantly increased at the onset of calf pain and was associated with significant increases in the number of leucocytes and in the filterability rate of the monocyte subfraction, the latter persisting throughout the recovery period. No significant changes were observed in the other variables monitored, showing that impairments in white cell rheology may be associated with ischaemia.

Aged↗