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Biomedical subjects

D Leone

Publications and source records attributed to D Leone.

At least 37 records · Page 2Linked to original sources

[Usefulness of the prevention of oxygen radical damage in the critical patient using the parenteral administration of reduced glutathione in high doses].

A hyperproduction of Oxygen Free Radicals (FRO) is frequently observed during stress, anoxia, hyperbarism and may worsen the clinical conditions of intensive care patients. The hyperproduction of FRO may be reduced by antioxidants. The glutathione (GSH) is frequently associated with organic antioxidant protective systems. Forty patients receiving a continuous infusion of 70 mg/Kg/die of GSH were compared with forty patients not receiving GSH; the patients in both groups were randomized for age, sex, and pathology. Some parameters which are indirect indexes of FRO hyperproduction were chosen: ethane in the expired air, plasma malondialdehyde, fibrinopeptide A and C5 activated complement fraction, also the erythrocyte membrane deformability was investigated. The results obtained in the group receiving GSH were compared with the control group and a significative difference was found indicating a reduced FRO production. These interesting results need more trials in order to confirm a real GSH involvement in the antioxidant organic protection. In any case the supplementation with antioxidants in the therapy of intensive care patients can be regarded as an interesting means to improve their clinical conditions.

Adolescent↗

Expression and functional characterization of a soluble form of vascular cell adhesion molecule 1.

Vascular cell adhesion molecule 1 (VCAM1) is a leukocyte adhesion molecule induced on human endothelium in vitro and in vivo by inflammatory stimuli. A truncated cDNA for VCAM1 was constructed, stably expressed in Chinese Hamster Ovary (CHO) cells, and the secreted recombinant soluble form of VCAM1 (rsVCAM1) purified to homogeneity by immunoaffinity chromatography. Immobilized rsVCAM1 is a functional adhesion protein, and selectively binds only VLA4-expressing cells, including human B and T lymphocytes, NK cells, and certain lymphoblastoid cell lines. T cell subset analyses indicate preferential binding of CD8+ memory cells. rsVCAM1 should prove valuable for the further study of the role of VCAM1 during inflammatory and immune responses in vivo.

Amino Acid Sequence↗

Posttranslational modifications of rat proenkephalin overexpressed in Chinese hamster ovary cells.

Rat proenkephalin was overexpressed in Chinese hamster ovary cells using the dihydrofolate reductase-coupled genetic amplification method. About 2 mg purified protein could be obtained from 250 ml conditioned medium; multiple successive harvests could be obtained from the same roller bottle. Degradation of proenkephalin released into the conditioned medium was reduced significantly in the presence of 2% fetal bovine serum. Forty-eight percent of recombinant proenkephalin was glycosylated; glycosylation could be entirely prevented by the addition of tunicamycin. Two-dimensional isoelectric focusing experiments showed that recombinant proenkephalin exhibited considerable charge heterogeneity, with two major unglycosylated isoelectric forms and six or seven glycosylated isoelectric forms. The estimated isoelectric points of the major unglycosylated proenkephalins were 6.0 and 6.1, while glycosylated proenkephalins ranged in pI from 5.7-6.1. Some of this isoelectric heterogeneity is due to phosphorylation; [32P] orthophosphate was readily incorporated into serine residues within newly synthesized proenkephalin.

Animals↗

Molecular analysis of atypical beta-thalassemia heterozygotes.

This paper reviews the molecular pathology of a heterogeneous group of beta-thalassemia heterozygotes which may be referred to as atypical beta-thalassemia. This group includes four different categories of heterozygous beta-thalassemia, which are characterized, respectively, by (1) normal MCV and MCH; (2) normal Hb A2; (3) normal MCV, MCH, and Hb A2 and imbalanced globin chain synthesis only or, (4) the presence of clinical manifestations. The first group is represented by a limited proportion of double heterozygotes for alpha- and beta-thalassemia. The second group includes two categories. One category is double heterozygotes for delta- and beta-thalassemia with the delta-thalassemia mutation in cis or in trans to beta-thalassemia. A number of delta-thalassemia mutations which produce this phenotype by interacting with beta-thalassemia have been described. The other category within the second group is heterozygotes for some mild beta(+)-thalassemia mutations. Within the third group, conclusive evidence for a mutation within the beta-globin gene cluster producing the silent beta-thalassemia phenotype has been obtained solely for a C----T substitution at -101 within the CACCC box of the beta-globin gene. Possible candidates are the complex rearrangements (-T, +ATA; -T, +ATATA) found at position -530 from the cap site. In the group of thalassemic hemoglobinopathies, a series of mutations mostly located in the third exon and producing elongated or truncated molecules have been recently reported. Most of the mutations are silent at the protein level, produce inclusion bodies in peripheral erythrocytes, and show a dominant transmission pattern or occur sporadically.

Codon↗

[Use of potassium canrenoate in cardiosurgery].

The influence of canrenoate of potassium, a new injectable antialdosteronic, on serum, urinary and intraerythrocyte ionograms has been evaluated as part of a random controlled study on patients submitted to ECC heart surgery. The results show that the drug maintains correct ionic homoestasis and gradualises and potentiates diuresis, in association with furosemide. The possible clinical implications of these results are discussed.

Adult↗

Minimal flow and half-closed system ventilation in lung surgery.

BACKGROUND: This study aimed at determining the applicability of minimal flow anaesthesia in lung surgery. METHODS: The standards anaesthesiological technique was modified to perform minimal flow half-closed system ventilation. For procedures on left lung orobronchial intubation was performed by a White no. 41 and no. 39 orotracheal tube, respectively in male and in female patients, in order to achieve a perfect tight of bronchial cuff and prevent gas loss from the circuit, because of the greater calibre of the right stem bronchus. The metal double lumen connector was replaced by a plastic tube that is clamped to exclude the lung from ventilation, whenever necessary. Fibrin glue was systematically applied on the bronchial stump or resected lung tissue before restoring ventilation. RESULTS: No significant changes were recorded in heart rate, arterial systolic and diastolic pressure, end-expiratoy CO2 concentration, oxygen saturation, airways maximum and minimum pressure. CONCLUSIONS: Minimal flow half-closed system ventilation can be easily performed also in pulmonary surgery provided that gas loss from the circuit is 50 ml/min by means of specific technical adjustments.

Aged↗

[Nutritional problems in the surgical patients with head and neck tumours. Literature review and personal experience].

During the last years the importance of the correct nutritional assessment as a part of the therapeutic process of the human pathologies has a greatly increased relevance. Still more in oncology, such relationship among nutritional assessment and good result of the therapeutic treatment have a fundamental importance. Among the neoplastic diseases those of the head and the neck result to be particularly aggressive, both for their nature and for the particular anatomical organization of such body areas, and the affected patients also need a precise evaluation of the nutritional assessment to obtain an optimal therapeutic result. On the basis of such premises and to their own clinical experience, the authors describe the main nutritional problems of the patients with tumours of the head and the neck and the possible therapeutic solutions.

Enteral Nutrition↗