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Biomedical subjects

P Santini

Publications and source records attributed to P Santini.

At least 37 records · Page 2Linked to original sources
PubMed2000

Field-dependent energy scales in URu(2)Si(2).

At low temperature, macroscopic properties of URu(2)Si(2) display a characteristic energy scale delta(0)(B) which decreases when a magnetic field is applied, and eventually vanishes at an extrapolated value of the field of about 40 T. We have performed inelastic neutron scattering measurements of the magnetic dynamics of URu(2)Si(2) in applied fields along the c axis of intensities up to 12 T. We show that delta(0)(B) is not related to gaps in the magnetic fluctuations spectra. This provides direct evidence of the fact that two distinct energy scales govern the physics of this compound.

Journal Article↗
PubMed2000

Levy scaling in random walks with fluctuating variance

Truncated Levy flights with correlated fluctuations of the variance (heteroskedasticity) are considered. A stylized model is introduced, in which the variance fluctuates between two possible values following a Markov chain process. Analogously to conventional truncated Levy flights with fixed variance, the central part of the probability distribution function of the increments at short time scales is found to be close to a Levy distribution. What makes these processes interesting is the fact that the crossover to the Gaussian regime may occur for times considerably larger than for uncorrelated (or no) variance fluctuations. Processes of this type may find direct application in the modeling of some economic time series, in which Levy scaling and heteroskedasticity are known to coexist.

Journal Article↗
PubMed2000

Body composition changes induced by chronic ethanol abuse: evaluation by dual energy X-ray absorptiometry.

OBJECTIVE: Nutritional disorders in alcoholics remain one of the most relevant medical problems in Western societies. As ethanol can supply >50% of the dietary energy in alcoholics, body composition alterations may easily occur. The aim of the present study was to evaluate the influence of chronic alcohol consumption on body composition in alcoholics compared to healthy social drinkers. METHODS: A total of 34 alcoholics defined according to DSM III R criteria, aged 41.6 +/- 9.3 yr and with a body mass index (BMI) 23.8 +/- 3.2 kg/m2, were consecutively enrolled in the study. In addition, 43 healthy male social drinkers were used as controls. Body composition was assessed using dual energy x-ray absorptiometry (DXA), and dietary habits were determined by a 3-day food diary. RESULTS: Mean daily alcohol intake was 194 +/- 62.4 g/day in alcoholics and 35.7 +/- 5.2 in healthy subjects (p < 0.0001). Body weight did not differ between alcoholics and controls (70.1 +/- 9.9 vs 71.8 +/- 6.4 kg). Alcoholics had a lower percent body fat (PBF) than control subjects (18.7 +/- 3.7 vs 23.9 +/- 3.9%; p < 0.01), as well as a lower fat mass content (13.4 +/- 3.8 vs 17.0 +/- 3.7 kg; p < 0.01). BMI was highly correlated with PBF in the patient population studied (R = 0.79; p < 0.0001). Significantly higher waist-to-hip ratios were found in alcoholics than in healthy subjects (p < 0.01). No correlation was found between dose of ethanol or duration of alcohol abuse and any of the variables examined. CONCLUSIONS: Alcoholics showed a reduced fat mass and a good preservation of lean body mass with respect to control subjects, and duration of alcohol use and alcohol dose did not seem to influence body composition. These data suggest that, unlike control subjects, alcoholics cannot store the calories provided by ethanol as fat deposits.

Absorptiometry, Photon↗
PubMed1996

["N2" carcinoma of the lung. Therapeutic considerations].

The follow-up of 240 N2 lung cancer cases operated in Thoracic and Cardiovascular Surgery Department of Florence is examined. The analysis is performed in compliance with global survival, "T", histology, therapeutic choices. Global survival is 81% after 6 months, 60% after 1 year, 37% after 2 years, 26% after 3 years, 23% after 4 years, 23% after 5 years. Significative difference on survival does not exist between principal histologic types (squamous, adenocarcinoma, adenosquamous). Raising the "T" survival decreases, but only for adenocarcinoma. Different therapeutic options (only surgery, surgery+radiotherapy, surgery+chemotherapy, surgery+radio and chemotherapy) do not influence the survival in a way statistically significative. From the literature, any certainty about radiotherapy and chemotherapy associated to surgery for N2 lung cancer treatment does not exist at the moment. Thus radical surgery is essential.

Adenocarcinoma↗
PubMed1993

Antimicrobial effect of chlorine on Yersinia enterocolitica.

The effects of chlorine at varying pH, culture media and incubation temperatures on one type and two wild type strains of Yersinia enterocolitica were studied. Exposure to 1 and 5 mg 1(-1) did not diminish viability, even after prolonged exposure. A level of 10 mg 1(-1) was required to achieve a 5-log reduction in 120 s for the type strain and 80 s for the wild strains. There was an increase of more than 30% in the rate of disinfection with a 10 degrees C rise, a remarkable increase in antimicrobial activity at pH 5-log reduction in 20 s, as well as marked neutralization of the effect in the presence of 0.1% peptone. Younger cells were more susceptible than older ones, and those from liquid medium more resistant than those from solid medium. Incubation temperature of a 24-h inoculum failed to show any influence. Lastly, there was a noteworthy demand for free chlorine by bacterial biomass, with agreement of the curve depicting the drop in free chlorine in the presence of inoculum with biphasic kinetics of survival curves.

Cell Survival↗
PubMed1992

Inappropriate emergency test ordering in a general hospital: preliminary reports.

An assessment was made on emergency laboratory test ordering at Udine General Hospital (Italy) to investigate the reasons for the excessive number of requested tests. All the orders for emergency laboratory tests during one week in June 1990 were studied. For each test the time of the order was recorded for every day of the week. The most important aspect of our investigation is the distribution of the orders during the day: in fact, test orders reached two peaks, the upper between 7 and 11 a.m., and the lower between 3 and 6 p.m. The analysis of the record cards showed that 42% of the orders were inappropriate. These preliminary findings were very useful in making the consensus on a Quality Assurance program easier, to improve the use of the Emergency Laboratory by doctors and nurses. Some preliminary results in the Emergency Medicine Department confirmed the validity of this program.

Clinical Laboratory Techniques↗
PubMed1989

[Idiopathic monoclonal gammopathy. Long-term study of 313 cases].

The records of 519 patients with a paraproteinaemia who where examined at our institutions before January, 1, 1983, were reviewed. After patients with multiple myeloma, macroglobulinemia, amyloidosis, lymphoma or related diseases had been excluded, 363 cases remained which fulfilled the criteria for a diagnosis of idiopathic monoclonal gammopathy (IMG). Also excluded were the cases in which follow-up efforts failed and those in which the paraprotein had disappeared. A long-term study was thus possible in 313 patients with IMG. They were arbitrarily subdivided into two groups: 213 patients with a follow-up of 5-8 years and 100 patients whose follow-up was longer than 8 years. Fourteen per cent of the patients from the former group and 18 per cent from the latter developed a malignant B cell dyscrasia, on the average this event becoming clinically detectable after 63 months (27-138 months) from initial recognition of the paraprotein. A retrospective analysis of the clinical data at the diagnosis of IMG, revealed that none of the patients could have been identified in advance in whom a malignant transformation later occurred.

Adult↗
PubMed1986

Ketanserin (S2-receptor blocking agent), platelet activity and chronic alcoholism.

Ketanserin is a pure and selective antagonist of serotonin S2-receptors in blood vessels, platelets and bronchial tissue. It antagonizes serotonin-induced vasoconstriction, bronchoconstriction and platelet aggregation, and indirectly it blocks platelet release reaction. Ketanserin has little or no effect on healthy subjects. Serotonin-induced or serotonin-potentiated platelet aggregation is inhibited in blood drawn from ketanserin-treated healthy volunteers. Oral or parenteral ketanserin treatment did not cause major changes in beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) plasma concentrations, when basic values were normal. Increased microaggregate formation was found in alcoholics and heavy drinkers. It was also found that beta-TG and PF4 levels were higher in these patients than in the controls. Ketanserin treatment tended to normalize these protein levels in such patients.

Adult↗