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At least 1,657 records · Page 92Linked to original sources
PubMed2006

Building the edentulous impression--a layering technique using multiple viscosities of impression material.

The purpose of this article is to introduce a novel impression technique. The procedure demonstrates a building, or layering, method of impression making that maintains the integrity between layers of the impression materials of varying viscosities and controls the path of insertion, minimizing the incidence of overextension. To build a detailed impression of the tissue-bearing surfaces, the clinician selects the proper viscosity of impression material based on the diagnosed tissue condition.

Dental Impression Materials↗
PubMed1991

[Comparison of the M1-blocker with the H2-blocker regarding their effects on gastric pH and viscosity under general anesthesia].

In a prospective, controlled, randomized trial measuring the gastric juice pH and viscosity, 30 patients under general anesthesia received M1-blocker; pirenzepine or H2-blocker; ranitidine. The gastric juice pH value was significantly higher (P less than 0.05) both in the pirenzepine and the ranitidine group than in the control group. While in the pirenzepine group the viscosity of gastric juice was unchanged, in the ranitidine group it was reduced. The results suggest that pirenzepine offers more effective prophylaxis against stress ulcer than ranitidine.

Adult↗
PubMed1990

Preliminary investigation of alterations in blood viscosity, cellular composition, and electrophoresis plasma protein fraction profile after competitive racing activity in Thoroughbred horses.

In this preliminary investigation, various hematologic variables potentially influential in determining the degree of blood viscosity were evaluated in 10 Thoroughbred horses subjected to competitive acute running exercise. Following completion of sprints over a distance of 1.25 miles, mean percent (+/- SD) increases in PCV (38.3 +/- 12.9%), RBC (47.8 +/- 15.3%), and rouleaux index (232.7 +/- 176.8%) were recognized. Simultaneous increases in total plasma protein (28.3 +/- 5.31%), serum albumin (26.7 +/- 6.80%), alpha 1-globulin (60.0 +/- 49.0%), alpha 2-globulin (25.5 +/- 27.9%), beta 1-globulin (46.7 +/- 21.1%), beta 2-globulin (35.0 +/- 50.6%), gamma 1- and 2-globulins (38.7 +/- 29.6%), and plasma fibrinogen (12.5 +/- 10.4%) concentrations increased simultaneously. Horses also had consistent decreases in albumin:globulin ratio (-10.0 +/- 7.43%). Alterations in these hematologic values after acute running exercise in Thoroughbred horses accompanied increases in serum (69.3 +/- 39.7%), plasma (39.7 +/- 11.9%), and blood (134.7 +/- 55.3%) viscosity.

Animals↗
PubMed1990

[Relationship among blood pressure, viscosity of blood and cerebro-vascular disease].

In this article, 163 cases of hypertension patients and 117 cases of stroke patients with acute period including 43 cases of hemorrhagic strokes and 74 cases of ischemic strokes were analyzed between average arterial blood pressure and blood viscosity. The curves of relation of blood pressure versus blood viscosity in the hypertension patients' group showed "M" shape. The hemorrhagic stroke patients were located by up-side of the "M" shape curve and the ischemic stroke patients were situated by the down-side of the "M" shape curve.

Aged↗
PubMed1990

[Changes in blood viscosity and erythrocyte deformability in patients with dyslipidemia treated with binifibrate].

31 patients afflicted with primary hyperlipidemia who did not improve after 30 days on a diet were treated with 1800 mg/day of binifibrate. We measured the total cholesterol level and triglyceridemia, as well as blood viscosity and red cell deformability at day 0, 30, 60, 90 of treatment. We found a statistically significant decrease in cholesterol and triglyceride levels as well as blood viscosity, and an increment of red cell deformability which improved the circulatory dynamisms augmentin the tissular perfusion in these patients.

Aged↗
PubMedDate not supplied

[Influence of the viscosity of the swallowed food bolus on the motility of the pharynx].

In 9 young men, healthy volunteers, we studied the effect of dry swallows, liquid and paste swallows on the pharyngeal motility. The viscosities of liquids and past were 200 centipoise (cP), 300 cP and 60000 cP, respectively. The bolus volume was 10 ml. For pharyngeal manometry we used two strain-gauge manometric probes taped together, so that a total of six transducers were staggered at 1.5 cm intervals. After its passage through the nose, the assembly was positioned so that all its transducers faced posteriorly, and manometric activity was recorded from oropharynx, hypopharynx and upper esophageal sphincter (UES). We also recorded infra-hyoid electromiographic activity. The amplitude and duration of the oropharyngeal and hypopharyngeal peristaltic pressure complex were not changed by the different boluses. The velocity of peristaltism propagation between oropharynx and UES was slower for paste than for liquids or dry swallows. The increased of viscosity was associated with longer duration of UES relaxation, and greater intrabolus pressure in hypopharynx and UES. The infra-hyoid electromiographic activity was longer for paste than for liquids or dry swallows. These findings suggest that pharyngeal motility is affected by the characteristics of the swallowed bolus.

Adolescent↗
PubMedDate not supplied

[The effect of plasma viscosity on the resistance of erythrocyte movement along capillaries].

By means of three-dimensional mathematical model describing movement of an asymmetric erythrocyte along the capillary of a small section the effect of the viscosity of the blood plasma on the resistance value to the erythrocyte movement in microvessels was studied. The model takes into account the elastic properties of the erythrocyte, the volume and area of its surface and the mobility of the membrane performing the rotation. It is shown that for characteristic conditions of hemodynamics experimentally observed in the microcirculation system the pressure gradient on the erythrocyte ends is 3-5-fold above the difference of pressures at the ends of plasma column of similar length. The dependence of the pressure gradient at the erythrocyte ends, which accounts for its movement along the capillary, on plasma viscosity is determined at different values of erythrocyte velocity.

Blood Viscosity↗
PubMed1989

The erythrocyte sedimentation rate, C-reactive protein, plasma fibrinogen and viscosity in chronic renal disease patients with infection.

The sensitivity of the C-reactive protein (CRP) measurement as an indicator for infection in patients with chronic renal disease was compared to that of ESR, fibrinogen and plasma viscosity measurements. The ESR, fibrinogen and plasma viscosity did not correlate with the presence of infection, whereas the CRP level was elevated in the majority of patients with infection/fever and decreased when fever subsided.

Adolescent↗
PubMed1987

The effect of fish oil on lipid profile and viscosity of erythrocyte suspensions in CAPD patients.

In this study we investigated the effects of a daily supplementation of 6 g Super-EPA containing 3 g of the marine fatty acids eicosapentaenoic acid (EPA, C 20:5 omega-3) and docosahexaenoic acid (DHA, C 22:6 omega-3) for a period of 8 weeks in nine patients on continuous ambulatory peritoneal dialysis. The concentrations of both HDL2 cholesterol and total HDL cholesterol increased (P less than 0.05) and there was a marked reduction in triglycerides (P less than 0.05). The viscosity of erythrocyte suspensions at a haematocrit of 0.80 decreased at most shear rates, suggesting an increased erythrocyte deformability. Mean corpuscular volume decreased (P less than 0.05) and total cholesterol and phospholipids in the erythrocyte membrane increased. We conclude that the daily use of 3 g of omega-3 polyunsaturated fatty acids by CAPD patients produces favourable effects on lipid profile and viscosity of erythrocyte suspensions, which may be of importance in protecting these patients against a further progression of atherosclerosis.

Blood Viscosity↗
PubMedDate not supplied

[Blood viscosity in ischemic heart disease].

Through a capillary viscometer we measured venous and arterial blood viscosity (BV) in 25 patients with the diagnosis of ischemic heart disease (IHD); 10 of them with unstable angor pectoris (UA) and 15 with acute myocardial infarction (MI). The control group consisted of 100 normal individuals in whom the normal values were 2.70 +/- 0.10 centipoises, where as in patients with AU the values were 4.03 +/- 1.40 centipoises and in the group with MI was 3.65 +/- 1.20 centipoises. Statistically, we correlated the BV obtained in both groups with the following parameters: coronary risk factors, cell blood count; serum glucose, cholesterol and triglycerides as well as the number of coronary arteries involved. The levels of venous and arterial BV were elevated in both groups of patients in comparison with the control group. We concluded that arterial and venous BV is elevated in patients with IHD independently of the hematocrit. This suggest the probability of some other factors such as plasmatic viscosity and platelets aggregation could play a role in the BV elevation of this group of patients.

Adult↗
PubMed1979

Amelioration of blood viscosity in sickle cell anemia by pentoxifylline. A case report.

An 18 year old female patient with homozygous sickle cell anemia (HbSS: HbS 65% and HbF 4.9%) has been suffering from painful hemolytic crises about once a week since her childhood. Under treatment with pentoxifylline (2.4 gm daily in three divided doses), the blood viscosity decreased from 6.7 to 4.9 cP (normal: 4.3 to 5.3 cP at shear rate 46/sec) and the erythrocyte filtration accelerated from 127 to 77 sec (normal: 30 to 49 sec). Though hemolysis could not be prevented by pentoxifylline, there was no further demand for analgesic medication even in the hemolytic state. By decreasing blood viscosity and improving microcirculation, pentoxifylline may prevent the vasoocclusive complications of sickle cell anemia.

Adolescent↗
PubMed1988

[Nocigenic changes in the blood viscosity indices of rats].

One-minute subcutaneous nociceptive stimulation increased arterial pressure by 15-20 mm Hg in Wistar rats. The 20-min. stimulation altered rheological properties of the blood: the hematocrit, the plasma viscosity and protein concentration, the erythrocyte aggregation velocity, the utmost tension of shift, and the viscosity of the blood standardized by hematocrit--all these parameters increased. These changes are rather unfavourable for flowing properties of the blood. The changes of the blood rheological properties were reflex-based, the problem of compensatory shifts is discussed.

Animals↗
PubMed1988

Diabetic hypertension--the importance of fibrinogen and blood viscosity.

Fibrinogen and blood viscosity were measured in 72 stable non-insulin dependent diabetic subjects, 31 without hypertension, and 41 who had treated hypertension. The hypertensive group had higher plasma fibrinogen levels and blood viscosity. As both these rheological variables have been associated with micro- and macro-vascular disease, these findings may provide a possible explanation for the mechanism of the increased vascular disease seen in hypertensive compared with normotensive diabetic subjects.

Blood Viscosity↗
PubMed1988

[Whole blood and plasma viscosity and erythrocyte aggregation in power plant repairmen].

Forty-nine workers employed at power plants repairs underwent examinations and tests of: circulatory system, whole blood and plasma viscosity, red cell aggregation, concentration and electrophoretic picture of serum proteins, levels of glucose in blood and cholesterol and beta lipoproteins in serum. Ten per cent of the test workers exhibited slight deviations of the circulatory system. More pronounced changes, as compared to controls, were found in rheological factors: corrected blood and plasma viscosity and red cell aggregation were increased but hematocrit was decreased. Biochemical investigations showed a fall in serum total proteins and albumins and a rise in serum cholesterol and beta lipoproteins.

Adult↗
PubMed1988

Study of the factors affecting blood viscosity in patients with thromboangiitis obliterans. A preliminary report.

Hematocrit values, plasma fibrinogen levels, and erythrocyte deformability are well-recognized factors affecting blood viscosity. We studied the incidence of abnormalities in these factors among 17 patients suffering from thromboangiitis obliterans (Buerger's disease) compared with 14 normal age- and sex-matched control subjects. Hematocrit values and fibrinogen levels were higher, whereas the erythrocyte filterability index was lower among the patients with Buerger's disease (p less than 0.001). Incubation of washed erythrocytes from these patients with control plasma of blood type AB produced an improvement of the filterability index (p less than 0.005). Our findings suggest that patients suffering from Buerger's disease show, in addition to the well-recognized arterial lesions, an abnormality in the factors affecting blood viscosity. This may contribute to a worsening of the clinical manifestations. Evidence is presented suggesting that a plasmatic factor may be responsible for the impaired erythrocyte filterability.

Blood Viscosity↗
PubMed1987

[Effect of the functional groups of tocopherol molecules on lipid viscosity of mitochondria].

The influence of tocopherol and its analogue (oxychroman) on the microviscosity of mitochondrial lipids was studied, using spin labels. The viscosity of the lipid bilayer was shown to enhance with the increase in the antioxidant content in the membrane. Small concentrations of alpha-tocopherol (10(-5)-10(-6) mol/l) were shown to increase, while large concentrations (10(-3)-10(-4) mol/l) decreased the fluidity of the lipid bilayer. The influence of alpha-tocopherol on fluidity of the lipid bilayer depending on its concentration could be realized in two ways: by direct influence on the lipid bilayer and via reception. It was shown that alterations in the viscosity of the lipid bilayer depend on chroman cycle of tocopherols, while the temperature of structural transfer and effective energy of activation depend on the lateral phytyl chain.

Animals↗
PubMed1985

[The influence of viscosity-increasing pharmaceutic aids on the liberation of the peptide gonadotropin releasing hormone (GnRH) in solution].

The in vitro liberation of the peptide hormone GnRH from polymer solutions was studied as a function of the viscosity of the polymer solutions. The liberation experiments were performed with a flow through dialysis apparatus. From solutions of dextran, carboxymethylcellulose, hydroxyethylcellulose, and polyvinylpyrrolidone the release of GnRH is prolonged whereas the release of GnRH from highly viscous solutions of methylcellulose and polyacrylic acid is not. The delivery process was found to be diffusion-controlled in solutions of dextran, carboxymethylcellulose, and hydroxyethylcellulose. In solutions of polyvinylpyrrolidone the diffusion-controlled prolongation of the GnRH release is additionally influenced by binding of the peptide to the polymer. The results imply that in these polymer solutions the diffusion coefficient of GnRH does not obey the classical relation D approximately 1/eta which is often used to predict liberation from viscous solutions. Thus, the measured macroscopic viscosity of the polymer solutions is not relevant for the diffusion-controlled prolongation of the in vitro release of GnRH. This phenomenon can be explained by the obstruction effect and the microviscosity of the polymer solutions. The described rapid and simple method can be applied for the quantitative determination of the prolonged release in polymer solutions based on diffusion-controlled processes and is useful in the comparison of the efficacy of various polymeric additives. Furthermore the method allows the quantitative proof of the decrease of diffusion in viscous low-molecular solutions and the proof of prolongations of delivery due to the binding of the investigated drug to the polymer.

Diffusion↗