Search results for "VISCOSITY"
showing 10 items of 542 documents
Clinical conditions responsible for hyperviscosity and skin ulcers complications
2017
In this brief review, we have examined some clinical conditions that result to be associated to an altered hemorheological profile and at times accompanied by skin ulcers. This skin condition may be observed in patients with the following condtions, such as primary polycythemic hyperviscosity (polycythemia, thrombocytemia) treated with hydroxyurea, primary plasma hyperviscosity (multiple myeloma, cryoglobulinemia, cryofibrinogenemia, dysfibrinogenemia, and connective tissue diseases), primary sclerocythemic hyperviscosity (hereditary spherocytosis, thalassemia, and sickle cell disease). In addition, it may be present in patients with secondary hyperviscosity conditions such as diabetes mell…
Haemorheological components in the pre-geriatric and geriatric age range in a randomly selected Western Sicily population sample (Casteldaccia study)
1993
{Received 24.8.1992; accepted 7.12.1992} On a randomly selected western Sicily population sample (Casteldac cia Study: 600 subjects; 300 males and 300 females) of an age range from 40 to 79 years, were determined: Haematocrit (Htc) , blood vi scosity, plasma viscosity, filterability of whole blood and fibrinogen. Par ticipation was 97%, being 582 subjects (M = 287, F = 295). All the parameters measured showed a progressive increase with age and si gnificant differences were found between male and female subjects: Htc and blood viscosity were higher in male subjects (p < 0.01), while plasma viscosity, whole blood filterability and fibrinogen were higher in female subjects (p < 0.05). In …
Haemodynamic effects of long-term administration of sildenafil in normotensive pregnant and non-pregnant rats
2011
Please cite this paper as: Pellicer B, Herraiz S, Cauli O, Rodrigo R, Asensi M, Cortijo J, Serra V, Morcillo E, Felipo V, Simon C, Pellicer A. Haemodynamic effects of long-term administration of sildenafil in normotensive pregnant and non-pregnant rats. BJOG 2011;118:615–623. Objective To determine the effects of chronic administration of sildenafil citrateon healthy pregnant rats. Design In vivo animal experimental study. Setting Fundacion IVI–Instituto Universitario IVI, Valencia, Spain. Sample Pregnant and non-pregnant Wistarrats exposed to chronic administration of sildenafil. Methods Placental cross-barrier and feto-maternal relationship levels, maternal blood pressure, and haemody…
Vascular atherosclerotic disease: evaluation of the whole-blood filterability and red cell membrane microrheological pattern after intravenous admini…
1990
SummaryA study was carried out in 10 patients with vascular atherosclerotic disease to investigate the effects of a single dose of 300 mg pentoxifylline, given by intravenous infusion over 30 minutes, on various macrorheological and nzicrorheological parameters. Measurements were made at baseline, at the end of the intravenous infusion and again 30 minutes later of whole-blood filterability, erythrocyte membrane fluidity (using pyrene as probe) and transverse fluidity gradient (using fluorescent fatty acids as probes). The results showed that there was a significant variation in whole-blood filterability and the red cell membrane fluidity gradient after pentoxifylline. No difference, howeve…
High Output Heart Failure in Multiple Myeloma: Pathogenetic Considerations.
2022
The high output heart failure is a clinical condition in which the systemic congestion is associated to a high output state, and it can be observed in a non-negligible percentage of hematological diseases, particularly in multiple myeloma, a condition in which the risk of adverse cardiovascular events may increase, with a worse prognosis for patients. For this reason, though an accurate literature search, we provided in this review a complete overview of different pathogenetic mechanisms responsible for high output heart failure in multiple myeloma. Indeed, this clinical finding is present in the 8% of multiple myeloma patients, and it may be caused by artero-venous shunts, enhanced angioge…
Calculated Whole Blood Viscosity and Albumin/Fibrinogen Ratio in Patients with a New Diagnosis of Multiple Myeloma: Relationships with Some Prognosti…
2023
Background: In this single center study, we retrospectively evaluated the calculated hemorheological profile in patients with a new diagnosis of multiple myeloma, with the aim to evaluate possible relationships with some prognostic predictors, such as ISS, albumin levels, beta2-microglobulin, red cell distribution width, and bone marrow plasma cell infiltration. Methods: In a cohort of 190 patients, we examined the calculated blood viscosity using the de Simone formula, and the albumin/fibrinogen ratio as a surrogate of erythrocyte aggregation, and then we related these parameters to prognostic factors, using the Kruskal–Wallis and the Mann–Whitney tests, respectively. Results: From our ana…
Viewpoint: On the hysteresis in the human Achilles tendon.
2012
This viewpoint was stimulated by two observations: 1) the statistical skewness whereby numerous articles have reported tendon stiffness and Young9s modulus, but far fewer have reported tendon hysteresis; 2) in vivo human studies seem very often to report hysteresis values greater than 10%, suggesting either that there are methodological differences between human and animal studies, or that human tendons have a much poorer capacity to store and reutilize elastic energy. In this article we focus on the healthy human Achilles/gastrocnemius tendon (AT) since it has an important locomotor function and clearly a low AT hysteresis would allow elastic recoil for efficient locomotion. We discuss tha…
Equivalence of viscosity and weak solutions for the normalized $p(x)$-Laplacian
2018
We show that viscosity solutions to the normalized $p(x)$-Laplace equation coincide with distributional weak solutions to the strong $p(x)$-Laplace equation when $p$ is Lipschitz and $\inf p>1$. This yields $C^{1,\alpha}$ regularity for the viscosity solutions of the normalized $p(x)$-Laplace equation. As an additional application, we prove a Rad\'o-type removability theorem.
Asymptotic mean value formulas for parabolic nonlinear equations
2021
In this paper we characterize viscosity solutions to nonlinear parabolic equations (including parabolic Monge–Ampère equations) by asymptotic mean value formulas. Our asymptotic mean value formulas can be interpreted from a probabilistic point of view in terms of dynamic programming principles for certain two-player, zero-sum games. peerReviewed
Asymptotic Mean-Value Formulas for Solutions of General Second-Order Elliptic Equations
2022
Abstract We obtain asymptotic mean-value formulas for solutions of second-order elliptic equations. Our approach is very flexible and allows us to consider several families of operators obtained as an infimum, a supremum, or a combination of both infimum and supremum, of linear operators. The families of equations that we consider include well-known operators such as Pucci, Issacs, and k-Hessian operators.