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Biomedical subjects

G Ottaviani

Publications and source records attributed to G Ottaviani.

At least 37 records · Page 2Linked to original sources
PubMed1992

Simultaneous determination of cotinine and trans-3'-hydroxycotinine in human serum by high-performance liquid chromatography.

A high-performance liquid chromatographic method with ultraviolet photometric detection has been developed for the quantitation of cotinine and trans-3'-hydroxycotinine in human serum. A solid-phase extraction procedure was performed for the analytes and the internal standard, N-ethylnorcotinine, before chromatography. The use of a 30-cm reversed-phase column and a mobile phase of water-methanol-0.1 M sodium acetate-acetonitrile (67:24.5:6.5:2, v/v), pH 4.3, prevented the co-elution of caffeine with cotinine. The limit of quantitation observed with this method was 5 ng/ml for both cotinine and trans-3'-hydroxycotinine. The present method proved useful for the determination of serum levels of these metabolites, correlating with nicotine daily intake.

Chromatography, High Pressure Liquid↗
PubMed1992

How the steady-state cotinine concentration in cigarette smokers is directly related to nicotine intake.

The relationship between nicotine intake and steady-state cotinine concentration was studied in a sample of 125 subjects who smoked their usual brands of cigarettes. Nicotine and tar yield of cigarettes was determined with a smoking machine, under standardized conditions. Blood was drawn about 8 hours after the last cigarette was smoked and serum cotinine was measured by high performance liquid chromatography. Cotinine levels ranged from 11 to 400 ng/ml, and nicotine daily intake ranged from 1 to 33 mg/day. Regression analysis and the correlation coefficient, r = 0.919, significant at p less than 0.0001, showed that steady-state cotinine level was linearly and directly related to daily available nicotine, with an increase in correlation coefficient directly related to the increase in tar and nicotine yield. From the findings we also conclude that smokers of low-tar cigarettes do not tend to compensate for lower yields of nicotine.

Adolescent↗
PubMed1990

Characterization of bioacceptable carbon materials.

Bioacceptable carbon films deposited with a new low temperature technique have been investigated using Raman and X-ray photoelectron spectroscopy. Our results reveal a substantial similarity between the low temperature deposited film and the well-known bioacceptable low temperature isotropic (LTI) pyrocarbon. The Raman spectra, as well as the larger density and oxygen content in the bulk, lead to the speculation of the presence of the common tetrahedral bonds in these materials.

Carbon↗
PubMed1986

Properties of a new carbon film for biomedical applications.

The physical and chemical properties of carbon films, about 0.5 mu thick, deposited at low temperature (40-200 degrees C) by a new physical vapour deposition technique are presented, in comparison with those of pyrolytic carbon normally used in biomedical devices. Several analytical techniques have revealed that the thin carbon films present structural properties similar to those of pyrolytic carbon. For example, similar chemical bondings of C atoms are observed in both samples. Moreover the data suggest the presence in thin C films of both tetrahedral and graphitic bondings, as in the turbostratic structure typical of pyrolytic carbon. These results confirm the similar biocompatibility properties of both types of materials already established by in vivo experiments.

Carbon↗
PubMed1975

[Functional study of peripheral obstructive arteriopathies using an ultrasound flow detector].

An ultrasound flow detector was employed to measure pressure values at the ankle at rest and after physical exercise in 91 limbs belonging to 61 patients with various degree of arteriosclerotic occlusion, and in 10 healthy subjects. Basal values and percent falls after effort, and recovery times were compared with the symptomatologies and the different degrees of occlusion. Statistically significant correlations were observed.

Arteriosclerosis Obliterans↗
PubMedDate not supplied

Sudden Infant Death Syndrome (SIDS): a study of cardiac conduction system.

The theory that Sudden Infant Death Syndrome (SIDS) may be related to lethal cardiac arrhythmias or heart block due to structural abnormalities of the conduction system is attractive and still of particular interest. We analyze 69 autopsied cases of SIDS (46 males and 23 females, infants ranging in age from 3 to 365 days) and 24 age-matched cases of explained death (ED) as controls (16 males and 8 females), infants who died from extracardiac cause (cerebral and respiratory). SIDS and ED groups were divided into three subgroups according to the age: (A) from 3 to 60 days; (B) from 61 to 120 days; (C) from 121 to 365 days. Histological observations were focused on the cardiac conduction system (CCS) which was examined on serial sections with the technique devised by one of the present authors (L. Rossi). The following findings were observed: resorptive degeneration (97.10% of SIDS, 75% of ED), His bundle dispersion (33. 33% of SIDS, 16.66% of ED), Mahaim fibers (21.73% of SIDS, 8.3% of ED), cartilaginous meta-hyperplasia (5.79% of SIDS, 4.16% of ED), persistent fetal dispersion (24.63% of SIDS, 16.66% of ED), intramural right bundle (20.29% of SIDS, 25% of ED), left sided His bundle (20.29% of SIDS and 8.3% of ED), hemorrhage of the atrio-ventricular junction (15.94% of SIDS), septation of the bifurcation (13.04% of SIDS), atrio-ventricular node (AVN) dispersion (7.24% of SIDS), sino-atrial node hypoplasia (5.79% of SIDS), Zahn node (1.45% of SIDS), His bundle hypoplasia (1.45% of SIDS), intramural left bundle (1.45% of SIDS), AVN dualism (2.89% of SIDS), and His bundle dualism (2.89% of SIDS, 4.16% of ED). Only the presence of resorptive degeneration was significantly higher in SIDS than in ED cases (p = 0.004). Regarding the subgroups, the only significant difference was the higher presence of intramural right bundle in SIDS-A than in SIDS-B (p = 0.01). Despite the non-specificity of most of these findings, we believe that these changes, associated with particular conditions and/or neurovegetative stimuli, could cause potentially malignant arrhythmias. These data suggest the need for an accurate approach and examination of the cardiac conduction system in all cases of sudden death in infancy

Arrhythmias, Cardiac↗
PubMedDate not supplied

Pathology of the heart and conduction system in a case of sudden death due to a cardiac fibroma in a 6-month-old child.

A 6-month-old female infant considered to be in good health died suddenly and unexpectedly. Post-mortem examination was requested, with clinical diagnosis of sudden infant death syndrome. Gross examination revealed, however, the presence of a cardiac mass 4.5 X 4 x 3.5 cm in diameter. Histological examination of the heart confirmed the presence of a cardiac fibroma. In the present case, the sudden death could have been due to the left ventricular outflow obstruction, as much as to conductive disturbances caused by overstretching and compression of the atrioventricular node and of the bundle branches. Hemodynamic and conductive abnormalities are presumed to have provoked bradycardia degenerating into ventricular fibrillation and sudden death. Necroscopy studies of sudden death should always include histological examination of the cardiac conduction system but seldom do.

Female↗
PubMedDate not supplied

Sudden and unexpected infant death due to an hemangioendothelioma located in the medulla oblongata.

Herein, we report the case of a 4-month-old male infant dying suddenly and unexpectedly. Post mortem examination was requested with clinical diagnosis of Sudden Infant Death Syndrome (SIDS). Histological examination showed instead the presence of an hemangioendothelioma located in the medulla oblongata. Sudden unexpected death is the commonest form of death among babies between 1 month and 1 year of age. Although the vast majority of these fatalities are related to SIDS, a very small percentage is due to primary neoplasm. Necroscopy studies of sudden infant death should always include an accurate histological examination of the medulla oblongata on serial sections but seldom do.

Brain Stem Neoplasms↗