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Biomedical subjects

D Franchi

Publications and source records attributed to D Franchi.

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

Chromatographic methods for blood alcohol determination.

This review is focused on the different chromatographic strategies for blood alcohol determination which can be adopted for clinical and/or forensic purposes. Particular attention is paid to gas chromatography and to high-performance liquid chromatography. However, other analytical techniques in common use, such as chemical and enzymic methods, are also briefly presented, together with some, at present unusual or experimental, approaches, such as enzymic reactors and catalytic electrodes, which are suitable for application in column liquid chromatography. Finally, mention is made of the methods for the determination of acetaldehyde, the major ethanol metabolite, and of some proposed markers of chronic alcohol abuse, such as acetaldehyde-protein adducts and carbohydrate-deficient transferrin. In order to give the background of knowledge for the rational choice of an analytical strategy, an updated outline of ethanol metabolism and toxicology is presented, together with basic information for the interpretation of the results. Problems concerning blood sampling and storage are also discussed.

Chromatography↗
PubMed1992

Electrocardiographic changes in subarachnoid hemorrhage secondary to cerebral aneurysm. Report of 70 cases.

Electrocardiographic (ECG) alterations in the course of sub-arachnoid hemorrhage (SAH) have frequently been reported. The most frequent anomalies reported were lengthening of the QT interval, very negative or positive deep T waves, elevation or depression of the ST segment and the presence of U waves. We report 70 cases of SAH secondary to rupture of intracranial aneurysm (part of a larger group of 150) with ECG changes. We review the literature with particular regard to discussion of the possible pathogenesis of ECG changes and to the way they may affect the general clinical course.

Adult↗
PubMed1992

Endometriosis and nonobstructive müllerian anomalies.

We reviewed the case records of all women (N = 748) who underwent laparoscopy for infertility in our department from 1985-1990. The patients were divided into two groups, cases and controls, according to the presence of nonobstructive müllerian anomalies (N = 198) or absence of such anomalies (N = 545); women with obstructive müllerian anomalies (N = 5) were excluded. The patients were analyzed for the presence of endometriosis, malformation class, and productive history. The frequency of endometriosis was 30.8% in the women with nonobstructive müllerian anomalies, versus 38.5% in the controls (P = .209). Among the subjects with unicornuate uterus, the prevalence of endometriosis (55%) was significantly greater compared with the patients with other nonobstructive müllerian anomalies (28%) (P less than .05), but not compared with the controls (38.5%). Overall, no differences were observed in the frequency of endometriosis between infertile women with and without nonobstructive müllerian anomalies. Our results seem to exclude a common pathogenetic factor underlying endometriosis and nonobstructive müllerian anomalies.

Adult↗
PubMed1989

High-performance liquid chromatographic determination of morphine in biological samples: an overview of separation methods and detection techniques.

High-performance liquid chromatogrpahy with electrochemical detection at present suits most of the needs of toxicologists for the determination of morphine and some related compounds in biological samples, although fluorescence detection is still a useful alternative. Chemiluminescence detection may be promising, but needs further optimization of its coupling with HPLC to give the best performances. Morphine detection by absorbance spectrophotometry does not seem to allow the degree of sensitivity and selectivity from matrix interferences that is required in most instances. However, this approach is useful when morphine congeners undetectable by alternative means (i.e., heroin and morphine-3-glucuronide) are to be determined or when a general toxicological screening is required.

Chromatography, High Pressure Liquid↗
PubMed1986

Duration of oral procaterol protection from methacholine-induced bronchial obstruction.

The duration of action of procaterol, a beta-2-adrenoceptor agonist with an entirely new chemical structure, was assessed, in comparison to that of salbutamol, by inhalation of 43 inhalation units of methacholine at time intervals of 1, 3, 5, 7, and 9 hours after intake of the drugs. Procaterol and salbutamol were given in a double-blind random fashion, on different days, to 12 asthmatic children; pulmonary function tests (FVC, FEV1, MEF50, MEF25), skeletal muscle tremor, and vital signs (heart rate and blood pressure) were measured. Although there was no statistical significant difference between procaterol and salbutamol, protection of large and medium airways lasted for about five hours, while normal small airway patency was still present at seven hours. It is concluded that procaterol can be a good alternative beta-2-adrenoceptor agonist when the oral route is needed.

Adrenergic beta-Agonists↗
PubMed1984

Fluorescence studies of internal rotation in apohemoglobin alpha-chains.

The molecular dynamics of the apo alpha-chain of human hemoglobin have been examined using three different fluorescent probes, as well as by circular dichroism. All of these criteria are consistent with a significant loss of organized structure and molecular rigidity for the apo derivative. The apo alpha-chain thus contrasts with the apo beta-chain, which retains considerable rigidity and organized structure.

Apoproteins↗
PubMed1984

Serum group I pepsinogens level in cystic fibrosis.

Fasting serum pepsinogen 1 level was determined by radioimmunoassay in 30 patients with cystic fibrosis and in on equal number of age-matched healthy children. Serum pepsinogen 1 basal levels were significantly higher (49 +/- 18 ng/ml; p less than 0.01) in cystic fibrosis patients than in controls (38 +/- 12 ng/ml). The increased pepsinogen 1 level did not correlate with the levels of Po2 and Pco2 tensions, fat balance or basal and maximum acid outputs. It is concluded that the mechanisms which lead to a rise of serum pepsinogen 1 in cystic fibrosis are unknown. However these findings could provide useful information with regard to the biology of a disease whose physiopathology is still unknown.

Adolescent↗
PubMed1982

Folding domains as functional tools in allosteric systems: a heme-dependent domain in hemoglobin beta subunits.

We have investigated the denaturation by guanidine hydrochloride (Gdn X HCl), temperature, and pH of hemoglobin beta subunits and of the peptides beta (1-146), beta (56-146), and beta (1-55). The last peptide was insensitive to all of the three agents. In the other polypeptides denaturation by Gdn X HCl and temperature showed the presence of several structural domains characterized by different stabilities. Analyses of the data obtained in Gdn X HCl indicated the presence in beta subunits of an alpha-helical domain involving some 40 amino acids whose free energy of denaturation is only 2000 cal. This domain is heme dependent, and removal of heme in apo-beta (1-146) abolishes the presence of the domain as a structural entity. Acid denaturation reveals in beta subunits, apo-beta (1-146), and beta (56-146) the presence of buried histidines with very similar characteristics, indicating a similar tertiary structure in the three polypeptides. This suggests that removal of the heme produces an unfolding of beta subunits, involving preferentially the 1-55 portion of the chain. This portion of the polypeptide contributes substantially to the formation of the alpha 1 beta 2 interface in hemoglobin. The low stability of this domain implies a very small contribution to the stability of the system as a whole. Instead it makes it very sensitive to conformational attitudes of the heme, suggesting a role in the mechanism of ligand binding cooperativity and subunits interactions in hemoglobin.

Allosteric Site↗
PubMed1981

Molecular dynamics of hemoglobin subunits as seen by fluorescence spectroscopy.

Fluorescent conjugates of beta A subunits and their respective heme-free derivatives have been prepared in which a 1,5-N-iodoacetylaminoethyl-5-naphthylamine-1-sulfonate probe has been specifically placed at the beta-93 or beta-112 cysteine. The fluorescence anisotropy decay and static fluorescence polarization of these conjugates have been examined. Fluorescence measurements have also been made using 1-anilino-8-naphthalenesulfonate complexes, as well as the intrinsic fluorescence of the tryptophan groups. For the cases of the beta-93 and beta-112 conjugates there is substantial evidence for internal rotational freedom of the subunits. The internal mobility of the polypeptide is especially pronounced for the beta-112 conjugate. In contrast, the 1-anilino-8-naphthalenesulfonate probe placed within the heme pocket shows no indication of any rotation, other than that associated with the entire beta-subunit. Tryptophan fluorescence has been measured for the apo-beta subunits and for the peptides beta (1-55) from hemoglobins A and S. Perrin-Weber plots show the presence of multiple rotational modes suggesting mobility of the tryptophan groups.

Anilino Naphthalenesulfonates↗