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Biomedical subjects

A Fortini

Publications and source records attributed to A Fortini.

44 records · Page 3Linked to original sources
PubMed1984

Binding of low-molecular-weight heparin to aortic endothelium in rabbits.

The ability of a low-molecular-weight heparin to bind in vivo to the aortic endothelium in rabbits, compared with that of unfractionated extractive sodium heparin (UHEP), was investigated. For this purpose a low-molecular-weight heparin (LMWHEP) fraction (CY 216 A, 4,000-5,000 daltons) and an extractive UHEP (average 17,000 daltons) were labeled with 99m Tc and injected (0.2, 0.6, and 1.2 mg/kg) intravenously in groups of 6 rabbits. The binding to endothelium was then measured by counting the radioactivity of samples of abdominal aorta. Both heparins bound to endothelium with a fast, saturable, and reversible binding. No significant difference in the total bound radioactivity was found between the two heparins, suggesting that the investigated LMWHEP retains the ability to bind to the endothelium, contributing to its athrombogenic properties.

Animals↗
PubMed1984

In vitro investigation on the antiaggregating activity of ditazole.

The antiaggregating activity of ditazole, a non-steroidal antiinflammatory drug, was assayed in vitro on platelets from 16 subjects at high risk of thrombosis and from 14 healthy control subjects. This study was performed by the photometric method (Born) on platelet rich plasma (PRP), preincubated with ditazole at final concentrations of 1, 2.5, 4 and 40 micrograms/ml. Aggregation was induced by 1 and 2 microM ADP, 1 and 10 microM adrenaline and by 1 and 2 mM arachidonic acid (AA). Ditazole (1 microgram/ml) inhibited platelet aggregation induced by ADP (1 and 2 microM) in both groups and significantly reduced at all concentrations tested adrenaline (10 microM) induced aggregation in subjects at risk, but only at 2.5 micrograms/ml concentration in control subjects. Arachidonic acid (1 mM)-induced aggregation was significantly reduced by ditazole at all concentrations tested in control subjects but only at 2.5 micrograms/ml or more in subjects at risk. In both groups, however, aggregation induced by 2 mM AA was significantly reduced by ditazole at all concentrations tested.

Adenosine Diphosphate↗
PubMed1981

Platelet aggregation testing.

The authors review the methods currently used for platelet aggregation testing, which are mainly grouped in two classes: 1. methods measuring the sensitivity of platelets to aggregating agents and to mechanical stimulation in vitro and 2. methods measuring the spontaneous tendency of platelets to aggregate in vivo. Their advantages, their pitfalls and their potential usefulness are reported. The platelet behavior as assessed by the available methods is not strictly related to the true platelet behavior in circulating blood. Therefore much criticism is requested in the interpretation of the results obtained for a given group of subjects with a given method and any unallowed extrapolation must be avoided.

Adenosine Diphosphate↗
PubMedDate not supplied

Automatic eye tracker for excimer laser photorefractive keratectomy.

Acute overlapping of successive laser pulses onto the cornea during photorefractive keratectomy (PRK) is important to avoid refractive distortions. Most excimer laser systems performing corneal ablation lack control of the patient's eye movements and they cannot track the target corneal zone. We developed an eye-tracker based on television monitoring of the pupil and on automatic electro-mechanical deflection of the laser turning mirror, and we applied it to the ExciMed UV200 ArF work station (Summit Technology, Inc., Waltham, Mass.). Basic components are a black and white CCD camera and two fast stepping motors. The circuitry for target discrimination and tracking, and the optical imaging system are designed specifically. The tracker assembly does not interfere with the laser beam path nor with the operator's observation. Tracking of the pupil has been successfully achieved on different color irides, with an accuracy better than 0.1 mm in a 6 x 6 mm2 tracking field. Response time is less than 100 ms. Recordings of eye movements during PRK are presented. Tracking ablations have been performed on moving test eye-balls with plastic corneas. The proposed automatic system appears to be a reliable and effective method for the compensation of patient eye movements appears to be a reliable and effective method during PRK procedures.

Cornea↗
PubMedDate not supplied

[Chlamydia pneumoniae and atherosclerosis].

There is widespread consensus that atherosclerosis is an inflammatory disease. Between possible pathogenetic mechanisms, infective hypothesis has received increasing attention. Researches have recently focused their attention on the role of Chlamydia pneumoniae, a gram-negative intracellular organism, as infection by this bacterium has been demonstrated frequently associated with atherosclerosis. This review attempts to analyze and critically evaluate available data of the literature about the association between Chlamydia pneumoniae and atherosclerosis in order to provide updated elements of judgement concerning a possible future revolutionary scenario: the consideration of atherosclerosis as an infective disease, susceptible to prevention and treatment by means of antimicrobial therapy. More than twenty sero-epidemiological studies have found a two-fold or greater risk of cardiovascular events in subjects with serological evidence of Chlamydia pneumoniae infection. The organism has been identified in over 50% of atherosclerotic plaques examined by various histopathological techniques, while it has been only rarely found in normal artery tissues; moreover, viable Chlamydia pneumoniae has recently been isolated from coronary and carotid atherosclerotic plaques. Several experimental studies have shown that the biological properties of Chlamydia pneumoniae can explain its potential role in initiating and/or modulating plaque formation. The most relevant issue, i.e. the possibility of preventing or slowing progression of the disease with antimicrobial treatment, is still unsolved: only data from experimental studies on animals and four small intervention trials on humans are available, and their encouraging results require confirmation in larger prospective studies. In conclusion, while the association between Chlamydia pneumoniae and atherosclerosis seems to be established, it is still uncertain whether or not the organism plays a causal role in atherosclerosis and its complications. It is hoped that the results of wide scale clinical intervention trials with antibiotics for the secondary prevention of atherosclerotic diseases now in progress will clarify this problem.

Arteriosclerosis↗