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Biomedical subjects

M Fini

Publications and source records attributed to M Fini.

At least 181 records · Page 10Linked to original sources
PubMed1993

In vitro and ex vivo evaluation of methotrexate removal by different sorbents haemoperfusion.

The administration of high doses of Methotrexate (HDMTX) seems to be very effective in neoplastic treatment. Furthermore high doses of the drug could overcome the Methotrexate (MTX) resistance that it is possible to observe in some kind of cancers. To avoid several serious problems in the therapeutical application of HDMTX such as nephrotoxicity, hepatotoxicity and the difficulty to assess the right therapeutic range of the specific antagonist Leucovorin, a Haemoperfusion (HP) treatment could be very usefulL. In this study 3 anion exchange resins with different active group (trimethylammonium, dimethylethanolammonium and dimethylammina) and a spherical petroleum based charcoal were tested both in vitro and ex vivo to evaluate their capability to remove MTX. These results show a good strength and biocompatibility of the 4 sorbents and demonstrate the active group trimethylammonium resin as the most effective one.

Adsorption↗
PubMed1993

Hemoperfusion--state of art.

The authors make a general review of the state of art in HP with particular reference to the history, the main field of application, and the development of specific and selective sorbents. In this text, attention is paid to the application in the immunological field comparing the therapeutical removal of toxins with different sorbents. Next, the authors describe their experimental study with hemoperfusion using coated anion exchange resins for the treatment of acute respiratory insufficiency, the correction of metabolic alkalosis in pyloric stenosis, the removal of a high dosage of antiblastic agent in conjunction with the study of heparin subtraction by coated resins and finally the development of a particular type of resin for phosphates removal in uremia. These different fields of research recognize the necessity to look for a selective exchange by hemoperfusion because the concept of the "magic filter" that removes everything is not scientifically acceptable. Some explanations are given for the behaviour of the strong anion exchange resins regarding simple or complex ions and the influence of the chemical composition of the matrix. In conclusion, the authors underline that selective removal by HP is actually underutilized considering its potency.

Alkalosis↗
PubMed1993

Monitoring during haemoperfusion (HP).

The relationship between HP and haemodynamic changes is an area which until now has been largely uninvestigated as can be seen from the small amount of material published on this theme. The reasons for this indifference are mainly due to the low extracorporeal flow using during HP. The experiment with a new sorbent on animals must also be analyzed in cardiovascular aspects. This system is the most economical and simple for detecting the elution of vasoactive toxins. In this report the effect on the cardiovascular system of HDMTX and HP with a new trimethylammonium exchange resin versus control groups are evaluated. The results obtained clearly demonstrate the absence of haemodynamic side effects in both groups.

Animals↗
PubMed1993

Chemical sorbents: official guidelines and experimental approach.

To evaluate the biocompatibility of an anionic exchange resin with active group trimethylammonium and charged with chloride ions an experimental study was performed with different tests to determine cytocompatibility, acute systemic toxicity, intracutaneous reactivity, allergic sensibilization, haemocompatibility and release of acetone, dichloromethane, quaternary amines and heavy metals (Pb, Cu, Cd) in eluate. Thus an anionic exchange resin can link all anionic substances; an ex vivo study on the participation of the dissociated sodic heparin in the anionic exchange was also conducted. In fact every time an extracorporeal circuit is made an anticoagulant must be administered to the patient and the removal of the drug could cause serious haemocoagulative problems. The results of the study showed a high biocompatibility of the resin that did not cause different significant reactions in comparison with negative control substances. The coating of the resin with poly-hydroxy-ethyl methacrilate with a separation phase technique avoided heparin removal from blood. Therefore adjustment of the dosage may not be necessary during further in vivo experiments. Future researches aiming to evaluate the the effectiveness and the biocompatibility of the sorbent in a living being will be performed in the next steps of the study.

Animals↗
PubMed1993

[Prevention of post-ovariectomy osteoporosis in the rat. Comparative study of synthetic salmon calcitonin and eel calcitonin aminosuberic analogue].

The authors evaluate the efficacy of salmon calcitonin and aminosuberic analogue of eel calcitonin in the prevention of post-oophorectomy osteoporosis in rats. Both drugs, administered at the same dosage, are equally effective in preventing oophorectomy bone loss in rats. Besides, plasma biochemical evaluations demonstrate that calcitonins reduce bone turnover in treated rats, compared with control oophorectomized ones.

Absorptiometry, Photon↗
PubMed1993

In vivo experimental models on the evaluation of haemoperfusion.

We described some experimental models that were performed in rabbits and in swine in order to evaluate the efficacy of haemoperfusion treatment in hypochloremic alkalosis, uraemia and cytotoxic drug poisoning. In all the models, an extracorporeal circuit was used constituted mainly by a hematic sampling line and a cartridge, containing an anion exchange resin. Access to the blood stream was achieved by isolation and catheterization of the vessels either of the neck or of the leg, or both. The experimental model for the evaluation of haemoperfusion in hypochloremic alkalosis was carried out in rabbits by a pyloric stenosis because its size and weight are similar to new-born humans and its stomach is a simple monogastric one. The hypochloremia and alkalosis were achieved in only 4 hours. The other two experimental models were carried out in pigs because, in these cases, it was better to choose a large size animal with a nutritional similarity to humans, and with the capability to produce a stable chronic renal failure. The pigs were submitted to a bilateral ureter ligature to create a chronic renal failure or to a bilateral renal vessel ligature to avoid the physiologic precipitation of some drugs in renal tubules.

Alkalosis↗
PubMed1993

[The need for invasive diagnostic investigations (coronaro-ventriculography), interventions using extracorporeal circulation and coronary angioplasty in a defined population of Emilia-Romagna].

Working on a limited and controlled population of 100,000 living in the territory of Imola, in northern Italy, we tried to determine the need for coronary arteriography examinations, CABG interventions and PTCA procedures (similarly to the 1980 Minnesota survey). Indications for diagnosis or treatment were made according to agreement criteria of published data in 1990. In the 3 year time (1989-91) of this survey, indication to coronary arteriography was done in 433 pts. (367 atherosclerotic, 58 valvular and 8 with other etiologies). 57.7% (250/433) of the pts. were treated with CABG or PTCA, and 42.3% (202/433) were treated medically. Of the 367 pts. documented as having coronary ischemia, 54.5% had further invasive therapy: 35.4% CABG and 19% PTCA. For a population of 100,000 annual need has been estimated as follows: 145 catheterization procedures (99% coronary arteriography), 60 extracorporeal circulation procedures, and 24 PTCA interventions. Comparing programming estimates done by the national Health System for the needs of a population group in Northern Italy, it is clear that they are underestimating the real needs by 50%, and such an important underestimation implies important and pressing considerations for the future planning of the health care of this important pathology.

Adolescent↗
PubMed1992

[Experimental evaluation, in vitro and in vivo, of the risk of infection related to the use of the most common surgical sutures].

Many parameters contribute to surgical infections. Of these, surgical sutures with their chemical and physical characteristics like tissue and cell reaction degree and bacterial adhesion, play an important role. Cell vitality, bacterial adhesion, cell reaction degree were tested "in vitro" and tissue reaction with an "in vivo" model on: plain catgut, silk, polyglycolic acid, polyglactin 910, polyglyconate, polypropylene and nylon. Vitality cell test did not reveal any cytotoxicity; bacterial adhesion showed a lower adhesion degree to synthetic materials; cell reaction showed an increase in soluble receptor (sIL 2R) values in all materials except catgut. Tissue reaction was higher for resorbable sutures, and lower for nylon. These results suggest that special attention should be paid to the choice of suture materials.

Animals↗
PubMed1992

Hemoperfusion with a new anion exchange resin corrects the metabolic alkalosis in pyloric stenosis: an experimental demonstration.

An experimental model of hypertrophic pyloric stenosis was made by suture of the pyloric wall and gastrostomy in 10 rabbits under general anesthesia. Blood sampling indicated severe alkalosis and hypochloremia 3h 30 min after surgery. To correct the derangement, we tested an ion exchange resin (Dowex SAR), coated with a methacrylic hydrogel. A cartridge containing 18 g of this resin was inserted in an extracorporeal circuit. This chloride charged resin achieved uptake of HCO3- ions, and elution of Cl- ions. The electrolytic balance was fully restored after 10 min of treatment.

Alkalosis↗
PubMed1990

[The oxidative burst in the determination of immune response to synthetic materials].

Macrophages play an important role at the implant-tissue interface. Their activity is extremely complex but above all they are phagocytic cells. Phagocytosis is accompanied by a sequence of biochemical reactions known as "the oxidative burst" (BO). The fundamental physiological significance of this phenomenon is to provide the phagocytes with an efficient microbicidal mechanism. Our aim was to prepare an objective method for screening biomaterials that could influence macrophagic defence mechanisms against a possible implant contamination.

Animals↗
PubMed1990

[In vitro study of Staphylococcus epidermidis adhesiveness to suture materials].

In surgical divisions, where you can find the highest percentage of hospital infections, the surgical wounds are definitively the most frequent localization. The aim of our study was to evaluate whether bacterial-biomaterial interactions could influence the growth of infections in sutured tissues. We prepared a method for in vitro bacterial adhesiveness testing based on turbidimetric analysis. The results obtained show a different grade of bacterial adhesion in relation to physical and chemical characteristics of the material examined.

Bacterial Adhesion↗
PubMed1990

[Influence of suture materials on cell viability: a comparative experimental study].

Among the conditions that a material must satisfy to be considered biocompatible, most important is the non negative influence on the cellular viability of the surrounding tissue (cytocompatibility). The aim of our work was to evaluate in vitro, whether different types of materials (usually used in surgery), alter the viability parameters or the morphological characteristics of the cultured cells in contact with them.

Animals↗
PubMed1990

[Slowly reabsorbable suture threads in arterial microsurgery].

Authors present the results of an experimental research to evaluate the effectiveness of a slow resorbable suture (Polyglactyn 910) in arterial microsurgery. Healing of vascular wall, histologically evaluated, showed good reliability, compared to other suture materials.

Animals↗
PubMed1989

[Clinical characteristics and prognostic factors in chronic heart failure secondary to primary dilated cardiomyopathy and ischemic heart disease].

Natural history and prognostic factors in chronic congestive heart failure were investigated in 141 patients (100 males and 41 females), aged 58 +/- 14.5 years, who were hospitalized between 1981-1985. Heart failure was due to idiopathic dilated cardiomyopathy in 79 patients and ischemic heart disease in 62 patients. The following parameters were examined: sex, age, etiology, NYHA functional class, mean arterial blood pressure, heart rate, presence of 3rd heart sound, atrial fibrillation and left ventricular conduction delay, plasma sodium, echocardiographic shortening fraction, and treatment with vasodilators. Mean follow-up was 31 +/- 19 months. Overall survival was 83% at 1 year, 58% at 3 years and 49% at 5 years. No difference in mortality was evident between the two etiological groups, while the data on the cause of death showed a significant difference: sudden death was prevalent in the patients with ischemic disease (50% vs 24%), intractable heart failure predominated in patients with idiopathic dilated cardiomyopathy (69.7% vs 42.8%) (p less than 0.05). The multivariate analysis with the Cox model resulted in a negative prognostic significance of the male sex (p less than 0.02), III and IV NYHA functional class (p less than 0.04), heart rate at rest greater than 85 b/min (p less than 0.002) and the presence of left ventricular conduction delay on standard ECG (p less than 0.001).

Adolescent↗