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Biomedical subjects

B Tarquini

Publications and source records attributed to B Tarquini.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

Evaluation of the operative parameters for a human prolactin radioimmunoassay in serum.

A sensitive homologous radioimmunoassay (RIA) for human prolactin (hPRL) was evaluated. The experimental parameters of this double antibody solid phase (DASP)-hPRL-RIA are discribed. The RIA measures concentrations of hPRL as low as 1 ng/ml of human serum and allows repetitive measurements and accurate delineation of serum hPRL. The assay is specific for hRPL; only HGH shows a weak cross-reaction. The antigen recovery tests are quantitative. The serum concentrations of hPRL in a group of randomly selected male and female individuals averaged 6.7 +/- 3.3 ng/ml, respectively. In a chronobiological study performed on 21 subjects (5 male and 16 female), a statistically significant rhythm with a 24-h period was detected.

Adult↗
PubMedDate not supplied

Evidence for bone mass and body fat distribution relationship in postmenopausal obese women.

The measurement of bone mass, a reliable predictor of osteoporotic fractures, in obese subjects has yielded conflicting results and bone mass has been reported to be elevated, normal or decreased. These observations indicate that factors other than body weight may be involved in the less risk for osteoporosis in obese subjects. In order to clarify the role of body fat distribution on bone density we studied sixty postmenopausal overweight/obese women with Body Mass Index (BMI) over 25 kg/m(2). Thirty five age-matched, nonobese postmenopausal women, served as controls. Bone mineral density (BMD) was measured at the proximal and ultradistal non dominant forearm using a double energy X-ray absorption (DEXA) apparatus. The waist/hip circumferences ratio (WHR) was used, in obese group, as an anthropometric estimation of the abdominal (WHR>0.85) to lower-extremity (WHR>0.85) fat proportion. The results were analyzed by Student t-test, ANOVA, and multiple linear regression analysis. No difference was found in BMD between obese group and controls, but a highly significant (P<0.001) positive correlation has been documented between proximal and ultradistal radius bone mineral density and waist/hip ratio in the obese group. Instead not significant correlation was found with BMI. Regional fat topography may influence the bone mass independently of total adiposity and visceral fat was the primary parameter accounting for higher bone mineral density values. These finding suggest that women with android-like obesity are protected from osteoporosis.

Journal Article↗
PubMedDate not supplied

Influence of non-insulin-dependent diabetes mellitus on plasma endothelin-1 levels in patients with advanced atherosclerosis.

Endothelin-1 (ET-1) is an endothelium-derived vasoactive peptide with mitogen properties. Increased circulating ET-1 levels were found in patients with atherosclerosis as well as in patients with non-insulin-dependent diabetes mellitus (NIDDM) suggesting a role in the pathogenesis of these disorders. The aim of the present study was to ascertain the influence of the NIDDM on plasma ET-1 levels in patients with advanced atherosclerotic lesions. The circulating ET-1 levels were measured in 16 NIDDM patients (68.4 +/- 8.4 years) with macroangiopathy and in ten patients (65.3 +/- 11 years) with atherosclerosis without NIDDM. Twenty-two healthy subjects (43.1 +/- 18.3 years) served as controls. Circulating ET-1 levels were higher in NIDDM patients (6.8 +/- 2.8 pg/mL) than both controls (3.1 +/- 1 pg/mL; p < 0.001) and patients with vascular disease but without NIDDM (4.7 +/- 1.6 pg/mL; p < 0.04). No significant relationship was found between age and ET-1 concentrations, and no differences were noted between men and women in the control group. This study demonstrated that circulating ET-1 levels are increased in patients with atherosclerosis and that those with NIDDM showed the highest ET-1 levels. These observations strongly support a role for ET-1 in the pathogenesis of atherosclerosis and also suggest that this peptide may be involved in the development of atherosclerotic lesions in the NIDDM. We speculated that chronic exposure to hyperinsulinemia and hypertriglyceridemia in the diabetic patients could account for the increased ET-1 levels found in these patients.

Adult↗
PubMedDate not supplied

Chronomes, time structures, for chronobioengineering for "a full life".

Week-long or longer monitoring of blood pressure and heart rate, coupled to time-structure analyses, can help detect disease-risk elevations, as a warning of the need for a preventive prehabilitation. Within the normal range of physiologic variation, computer methods quantify time structures, or chronomes, that can serve as reference values. The major applied purpose for mapping chronomes is the detection of disease-risk syndromes such as blood pressure "overswinging" and heart rate "underswinging." Too much blood pressure variability (circadian hyperamplitude tension; CHAT), is a risk factor for vascular disease. Other risk syndromes are chronome alterations of heart rate variability (CAHRVs), consisting of a loss of "jitter", i.e., a reduced standard deviation of heart rate or of alterations in the spectral element of the heart-rate-variability chronome, such as in the correlation dimension, an endpoint of deterministic chaos. These alterations can again serve for prehabilitation. On the basic side, the spectral element of the heart-rate-variability chronomes extends from focus on the heartbeat's period of about 1 second to periods in heart rate and its standard deviation that are numerical equivalents of about 10.5- and about 21-year cycles of solar activity. A seemingly unnatural physiologic rhythm or pattern (such as one of 81.6 hours) may correspond numerically to a purely physical environmental rhythm. For example, interplanetary magnetic storms, with their cycles as external chronome components, trigger myocardial infarctions, strokes, and traffic accidents. The systematic monitoring of external rhythms along with physiologic ones for the concurrent analysis of rhythms with longer and longer periods could detect alterations anywhere in and between the 1 cycle/sec and the 1 cycle/10.5- or 21-years regions of the spectrum. Chronobiomimetic engineering for discovering both instantaneous and long-term chronorisk alterations can provide warnings of increased risk. If risk-lowering therapy is then instituted automatically, instrumented health care will be extended beyond the pacemaker-cardioverter-defibrillator, which focuses on the frequency of 1 cycle/sec. Instrumentation that automatically detects blood pressure that varies too much and heart rate that varies too little is needed for prompting prophylactic CHAT and CAHRV treatment. A database of reference values that can be used for chronodiagnosis is now accumulating.

Accidents, Traffic↗
PubMedDate not supplied

[Circadian aspects of iron metabolism. Changes of total iron binding capacity in patients with liver cirrhosis and in apparently healthy persons].

A group of 8 patients (M) with liver cirrhosis were studied. Each subject was standardized with rest time extending from 22,00 to 05,00 and meals scheduled at 08,00-08,30, 12,00-12,30, 17,30-18,00. Then was sampled at 04,00, 08,00 12,00, 16,00, 20,00, 24,00. In each sample of serum were determined iron, T.I.B.C. and L.I.B.C. All data were analyzed by macroscopic approach (chronograms) and by mean cosinor. A significant circadian rhythm was detected in all parameters, with a statistically valid difference between normal subjects and patients with liver cirrhosis in the mesor of T.I.B.C. and L.I.B.C.

Adolescent↗
PubMedDate not supplied

Circadian rhythms in blood, urine and gastric acid secretion of presumably healthy volunteers.

The mean conisor technique reveals statistically significant circadian rhythms for serum concentrations of iron, chloride, cortisol, PBI, the fibrinolytic activity of blood, urinary iron excretion and gastric acid secretion in studies covering a 24-h span for presumably healthy subjects. Quantification of these rhythms provides internationally comparable reference values both for the conventional clinical laboratory and for any special chronobiologic applications.

Adolescent↗
PubMedDate not supplied

Further steps toward a neonatal chronocardiology.

The study of 53 series of blood pressures at half-hour intervals from clinically healthy full-term newborns during the first days of life reveals various classifiers correlating with a history of high blood pressure: the circadian amplitude of diastolic blood pressure, the 50% range of systolic blood pressure and the standard deviation of heart rate.

Cardiovascular Diseases↗