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Biomedical subjects

L Coli

Publications and source records attributed to L Coli.

At least 19 recordsLinked to original sources
PubMed1998

Mechanical effects of heart pulse propagation on a vessel-graft suture line stress.

The effects of vessel joint where the both sides have different wall properties on the heart pulse propagation are investigated. Such a local disturbance can influence post-transplantation pathology and evolution of the organ inconsistency. Using a mathematical model, developed in a previous article, we perform analytical analysis and present some qualitative and quantitative estimations. The effects of jointed vessels with different thicknesses and radii on the local concentration of the pressure, radial wall displacement, bending moment and shear force are analyzed in detail. In particular, it is obtained that the bending and shear stresses at a joint sharply and strongly increase in comparison with the uniform vessel ones.

Blood Pressure↗
PubMed1998

Evidence of profiled hemodialysis efficacy in the treatment of intradialytic hypotension.

In the last 10 years the percentage of dialysis patients suffering from clinical intradialytic intolerance has greatly increased. Profiled hemodialysis (PHD) is a new technical approach, alternative to standard hemodialysis (SHD) for the treatment of intradialytic symptomatic hypotension. It is based on intradialytic modulation of the dialysate sodium concentration, using a dialysate sodium concentration profile elaborated by a new mathematical kinetic model. The aim of PHD is to reduce the intradialytic blood volume decrease, thanks to a dialysate sodium profile, which allows a reduction in the plasma osmolarity decrease, thereby boosting intravascular fluid refilling. This work aims at clinically validating the PHD technique, by testing its ability against SHD, to maintain a more stable intradialytic blood volume; this evaluation was supported by monitoring some hemodynamic parameters. Twelve dialysis patients on SHD treatment were selected because of their intradialytic symptomatic hypotension. Twelve SHD (one per patient) and 12 PHD sessions (one per patient) were performed to achieve the same sodium mass removal and body weight decrease on both PHD and SHD. During these sessions we monitored the blood volume variation % by the crit-line (a non invasive blood volume monitoring device), the mean blood pressure and heart rate directly and, finally, the stroke volume and cardiac output indirectly by bidimensional doppler-echocardiography. Comparison of the results obtained with the two techniques shows PHD to achieve a significantly more stable blood volume, blood pressure and cardiovascular function than SHD, in particular during the second and the third hour of the dialysis session.

Aged↗
PubMed1995

Structure of dialysis membranes and long-term clinical outcome.

The present comparative evaluation aims at establishing whether the basic structure of dialysis membrane is able to predict long-term clinical outcome. From a population of 1,256 patients on renal dialysis treatment, treated by the Institute of Nephrology and Dialysis of the St. Orsola University Hospital of Bologna from 1963 to 1993, 122 patients were retrospectively selected for the present study. Patients were divided into two different groups according to the kind of dialysis membrane used--cellulose-based (64 patients) and synthetic-based (58 patients) membranes. The parameters considered were: intradialytic biology, long-term biocompatibility, survival and morbidity, and cost/benefit. The results obtained demonstrate that cellulosic membranes can be said to cause a greater acute intradialytic biological response than synthetics, though not to a significant degree. There are, however, no significant differences in the biological changes from group to group. Nonsignificant differences were noted in long-term survival general morbidity. In terms of sheer cost, synthetic membrane treatment is anything up to 200% dearer than cellulosic.

Adult↗
PubMed1991

Cellular immunology in regular dialysis: a biological model for biocompatibility evaluation.

Cellular immunity represents an interesting biological model for biocompatibility evaluation of artificial materials owing to its sensitivity to contact with the external environment and its capability of modulating response reactions to foreign agents. Advanced methodologies such as flow cytometry and the immunoenzyme techniques in particular have given new insights into lymphocyte structure and functions, enabling analysis of the in vivo modification of these cells. By means of these sophisticated techniques we investigated lymphocyte activation and proliferation during one single haemodialysis session. Findings clearly show that increases in HLA antigen density (class I and II), DNA synthesis, and interleukin-2 receptor serum concentration (Il-2R) take place during the dialysis procedure, and reach their maximum during the first hour of extracorporeal circulation. The relationship between dialysis procedure and cellular immunity appears noticeable and is of potential value in the evaluation and quantification of the biocompatibility of different dialysis membranes.

Adult↗
PubMed1985

Ranitidine-associated hallucinations.

Adverse reactions involving the central nervous system have been rarely reported with ranitidine, a H2-receptor antagonist. A 72 year old female is described that developed visual hallucinations shortly after initiation of ranitidine therapy. Rechallenge with the drug resulted in both visual and auditory hallucinations following a single dose.

Aged↗
PubMed1981

Combined hemodialysis-hemoperfusion treatment reduces the time of substitutive therapy in chronic uremia.

Charcoal hemoperfusion has long been used in chronic uremia as an adjunct or substitute for conventional hemodialysis. In this study a regular combination of hemoperfusion and hemodialysis was used to cut down the weekly substitutive sessions from 3 to 2. Ten RDT patients were treated with the reduced-time schedule for 5-56 weeks. Clinical and metabolic conditions remained stable in all patients and no sign of inadequate treatment appeared. Long-term charcoal hemoperfusion was confirmed to be a safe and risk-free procedure. No change in platelets, white cells, red cells, fibrinogen and other hematochemical parameters were detected.

Adult↗
PubMed1979

Evaluation of a new coated charcoal for hemoperfusion in uremia.

A new coated charcoal for hemoperfusion in uremia was investigated in 14 patients with end stage renal disease who underwent hemoperfusion or combined hemodialysis-hemoperfusion (39 seances). Investigations concerned removal of small molecules, coagulation and hematological status and amino acids and some hormones equilibrium. Clinical observations were also made in all patients. The methacrylate-coated charcoal enabled the removal of "toxins" up to 5000 daltons and the total solute removal did not significantly differ from previous hemoperfusion systems. However, the new coating membrane showed improved biocompatibility, in terms of clinical side effects and/or platelet and fibrinogen alterations.

Biocompatible Materials↗