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Biomedical subjects

R Fanelli

Publications and source records attributed to R Fanelli.

At least 145 records · Page 8Linked to original sources

Quantitative profiling of prostaglandins and thromboxane by high-resolution gas chromatography-selected--ion monitoring.

The development and biological application of a rapid method for quantitative profiling of prostaglandins and thromboxane using high-resolution gas chromatography (HRGC) coupled with mass spectrometry in the selected-ion monitoring technique (SIM) are described. The method is based on the single-step extraction of prostaglandins from biological samples on C18 reversed-phase cartridges after addition of deuterated analogues as internal standards, followed by derivatization of functional groups and final analysis by HRGC-SIM with wall-coated open tubular persilanized capillary columns. Biological applications include the determination of endogenous arachidonic acid cascade profiles in rat tissue homogenates and thromboxane synthetase inhibition studies in human serum.

6-Ketoprostaglandin F1 alpha↗

Identification of an acidic metabolite of N-nitrosodiethanolamine isolated from rat urine.

N-Nitrosodiethanolamine metabolism was studied in order to clarify the mechanism(s) by which this compound elicits its carcinogenic effect. Samples of 24 h urine from rats given a single dose of N-nitrosodiethanolamine were collected. Gas chromatographic thermal energy analyses showed the presence of only one compound containing the nitroso moiety besides N-nitrosodiethanolamine. This compound was identified as the acidic derivative N-(2-hydroxyethyl)-N-carboxymethylnitrosamine by comparison with an authentic standard by means of gas chromatographic mass spectrometric analysis of the trimethylsilyl or pentafluorobenzyl esters. The amount of N-(2-hydroxyethyl)-N-carboxymethylnitrosamine excreted in the 24 h urine was about 6% of the N-nitrosodiethanolamine administered.

Animals↗

Significance of high voltage QRS anterior forces in young asymptomatic adults. Evaluation by wide-angle two-dimensional echocardiography.

Thirteen asymptomatic adults less than 40 years old who showed tall right precordial R waves on the ECG were examined by VCG, M-mode and two-dimensional echocardiography (2D Echo). Common causes of QRS anterior displacement, such as right ventricular enlargement or right bundle branch block, were excluded in each subject. Although each subject was normal at physical examination, 2D Echo revealed areas of left ventricular hypertrophy in eight of these 13 subjects. Four had a prevailing hypertrophy of the basal portion of the interventricular septum, three had an isolated apical hypertrophy, and one had a diffuse concentric left ventricular hypertrophy. Results were normal in five cases. 2D Echo classification was confirmed by heart catheterization findings, when available. The subjects with asymmetric septal hypertrophy showed low-voltage QRS leftward forces on the ECG and VCG. ECGs and VCGs were not useful in differentiating the subjects with atypically distributed left ventricular hypertrophy from the normals: high-voltage QRS leftward forces and T wave abnormalities were evident in some subjects of both groups. Tall right precordial R waves may constitute a marker of hypertrophic cardiomyopathy in asymptomatic young adults. 2D Echo is useful to exactly classify these subjects.

Adolescent↗

Determination of plasma and brain concentrations of trazodone and its metabolite, 1-m-chlorophenylpiperazine, by gas-liquid chromatography.

A sensitive and specific gas chromatographic procedure is described for the quantitation of trazodone and its active metabolite, 1-m-chlorophenylpiperazine (mCPP), in plasma and brain. After addition of internal standards, the samples were extracted with benzene and the extracts divided into two portions. One portion was evaporated to dryness, and residue dissolved in methanol and the solution injected into a gas chromatograph equipped with a nitrogen-selective detector, for trazodone quantitation. To the remaining half of the extracts, 100 microliter of heptafluorobutyric anhydride solution were added and the metabolite was measured as the heptafluorobutyryl derivative by electron-capture detection. Gas chromatography-mass spectrometry was used to confirm the specificity of the analyses. The kinetic profile of trazodone and its metabolite was investigated after oral administration of trazodone (25 mg/kg). The parent drug and its metabolite both accumulated in brain, reaching concentrations several times those in plasma. More mCPP than the parent compound entered the brain; the ratio of the area under the curve for trazodone to mCPP in plasma was about 4, whereas in brain it was only about 0.8.

Animals↗

GLC-mass fragmentographic determination of saccharin in biological fluids.

A specific and sensitive method is described for the determination of saccharin in biological fluids. The compound is extracted as its methyl derivative following a salt-solvent pair procedure and assayed by GLC with either flame-ionization or mass fragmentographic detection using ethylated or trideuteromethylated saccharin, respectively, as the internal standard for quantitation. Detector response was linear over concentrations of 50 mg/ml--10 micrograms/ml with multiple-ion detection mass fragmentography and from 2 micrograms/ml up to milligram levels with flame-ionization detection. Interference from endogenous substrates was never observed. Plasma kinetics and urinary elimination of saccharin in healthy human volunteers given the sweetener orally, acutely (50 mg/60 kg of body weight) or for 5 days (130 mg/60 kg of body weight/day divided over the three main meals), also are reported.

Body Fluids↗

Induction of mixed-function oxidase by chronic treatment with 2,3,7,8-tetrachloro-dibenzo-p-dioxin in female rats.

The effect of a 45-week treatment with different doses of 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) (0.01, 0.10 and 1.00 microgram/kg/week) was evaluated in female rat liver by determining cytochrome P-450 and b5 content and the activities of the enzymes cytochrome c reductase, aryl hydrocarbon hydroxylase (AHH) and 7-ethoxycoumarin O-deethylase (7-ECD); TCDD content in the liver was also measured. Cytochrome b5 and cytochrome c reductase were unaffected at any of the dose levels and cytochrome P-450 was significantly induced only at the highest TCDD dose, but marked induction of AHH and 7-ECD was apparent when the animals were treated with 0.01 microgram/kg/week; a clear dose-response relationship was present in the induction at the 2 lower doses (0.01 and 0.10 microgram/kg/week). The amount of TCDD found in liver tissue (1050, 4740 and 30 700 ppt, respectively, for 0.01, 0.10 an 1.00 microgram/kg/week) indicated a relatively higher accumulation of this compound at lower doses.

Animals↗

[Orthogonal ECG and a statistical system for computer diagnosis with ECG in chronic obstructive pneumopathy].

In 92 patients affected from chronic obstructive pulmonary disease (C.O.P.) undergoing spirometric evaluation, the ability of the Pipberger computer program for electrocardiographic interpretation to predict the presence of pulmonary disease with or without right ventricular hipertrophy was compared with that of the manually measured conventional and orthogonal (Frank system) electrocardiogram. The patients were classified as having mild, moderate and severe C.O.P. on the basis of spirometric data. Each system predicted the presence of C.O.P. with low sensitivity. P voltage in D2 greater than or equal to 2 mm (27,1%) and R/S voltage ratio in V5-V6 greater than or equal to 1 (22,8%) were the single conventional criteria more frequently satisfied. Results for 3 lead manual readings were only slightly lower: recognition rate of the R/S voltage ration in x lead less than or equal to 1,3 was 15,7%. The Pipberger program probabilistic answers were divided in "completely" and "partially" correct. Combined completely or partially correct diagnoses were made by the program 14,3% of patients with mild C.O.P., 17,2% of moderate and 48,8% of severe C.O.P. These results suggests that the Pipberger program has at least similar ability to predict C.O.P. compared with the 12 lead and orthogonal manually measured electrocardiogram.

Aged↗

[Systolic time intervals at rest in subjects under prolonged stress: a computerized analysis].

Systolic time intervals were measured in 21 endurance-athletes (middle and lung distance runners) with a computerized method. Data from athletes were compared with that obtained in 27 age-matched normal untrained subjects. Endurance athletes showed significantly inferior values than normal untrained subjects of heart rate, total ejection time (TET), rapid ejection time (TER), electromechanical systole duration (QS2). Authors suggest that these results, particularly the reduction of TER at rest, could be due to a more rapid ejection rate primary or secondary to a left ventricular after-load reduction, following the cardiovascular adaptations induced by training in these athletes.

Adolescent↗

2,3,7,8-Tetrachlorodibenzo-p-dioxin toxic effects and tissue levels in animals from the contaminated area of Seveso, Italy.

After the environmental contamination by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the area of Seveso, Italy, thousands of small domestic animals (mainly rabbits and poultry) died within a few weeks. Autopsies on dead animals showed various pathological signs, such as hepatic lesions and haemorrhage. TCDD was monitored in animal tissues by gas chromatography-mass fragmentography; rabbit liver levels corresponded fairly well to soil contamination, which indicated that this species can be used as a tool for tracking the presence of TCDD in the environment.

Accidents, Occupational↗

Quantitative determination of 6-keto-PGF1 alpha released by rat aorta: comparison of mass fragmentography and high resolution gas chromatography with electron capture detection.

Mass fragmentography (MF) and high resolution gas chromatography with electron capture detection (HRGC-ECD) were used for measuring 6-keto-PGF1 alpha, the stable hydrolysis product of prostacyclin (PGI2) released by fresh rings of rat aorta, incubated in the absence of the precursors arachidonic acid or prostaglandin endoperoxide (PGH2). The incubation medium was acidified, extracted, chromatographed on silicic acid column and derivatized. Comparable results were obtained analyzing each sample by MF and HRGC-ECD. Both methods proved to be suitable in terms of sensitivity and specificity for the measurement of 6-keto-PGF1 alpha produce by individual rat aortae.

6-Ketoprostaglandin F1 alpha↗

Transient right bundle branch block unmasking anteroseptal infarction concealed by left posterior fascicular block.

A case of acute anteroseptal myocardial infarction (MI) associated with transient right bundle branch block (RBBB) and a probably persistent left posterior fascicular block is reported. When the RBBB disappeared, small initial r waves were present in the right precordial leads concealing the evidence of MI. Finally, the electrocardiographic pattern evolved to an atypical form of incomplete left bundle branch block. An hypothetic role of the middle septal fascicle in this electrocardiographic evolution is discussed.

Bundle-Branch Block↗