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Biomedical subjects

E De Luca

Publications and source records attributed to E De Luca.

13 recordsLinked to original sources
PubMed2005

Using remifentanil and sufentanil in functional endoscopic sinus surgery to improve surgical conditions.

The purpose of the study was to compare three types of general anesthesia for functional endoscopic sinus surgery (ESS) with controlled hypotension measuring the quality of visibility of the surgical field and the blood loss during the operation. Seventy-one patients underwent endoscopic ethmoidectomy bilaterally for nasal polyposis and/or chronic sinusitis. The patients were divided into three groups according to the type of anesthesia they had: group A (sufentanil/sevoflurane), group B (remifentanil/propofol), and group C (fentanyl/isoflurane). The mean estimated blood loss for group A was 117.83 ml, for group B it was 100.5 ml and for group C it was 198.89 ml. The average quality of visibility of the surgical field was 1.57 for group A, 1.3 for group B and 2.79 for group C. The quantity of blood loss (p < 0.01) and the visibility of the surgical field (p < 0.001) demonstrated a difference among the three groups. Remifentanil and sufentanil during functional ESS enable controlled hypotension and a general improvement in surgical conditions.

Adjuvants, Anesthesia↗
PubMed2005

Antimicrobial activity of a nisin-activated plastic film for food packaging.

AIMS: To determine the effectiveness of a packaging film coated with nisin to inhibit Micrococcus luteus ATCC 10240 in tryptone soya broth (TSB) and the microbiota of raw milk during storage. A further aim was to examine the release of nisin from the activated film. METHODS AND RESULTS: An active package, obtained from nisin-treated film, was filled with 1 l of M. luteus ATCC 10240 (ML) suspension in TSB and stored at 4 and 25 degrees C for 2 days. After 24 h at 25 degrees C there was a remarkable reduction of M. luteus ATCC 10240 compared with the control, while at 4 degrees C a slight reduction was observed. Moreover, microbial growth was controlled when 1 l of three different kinds of milk was poured into the active package and stored at 4 degrees C for 7 days. The most significant results were observed in raw milk and pasteurized milk with a reduction of 0.9 log and 1.3 log, respectively. The release experiments showed that nisin release from the film was unpredictable, but it was favoured by low pH and high temperature. CONCLUSIONS: It appears that nisin-coated films were effective in inhibiting M. luteus ATCC 10240 in TSB and the bacterial flora in milk, and the release of nisin was pH and temperature dependent. SIGNIFICANCE AND IMPACT OF THE STUDY: Nisin-activated film may control bacterial growth, maintaining food quality, safety and extending the shelf-life of food products.

Animals↗
PubMed2001

Assignment of the complete disulphide bridge pattern in the human recombinant follitropin beta-chain.

The chemical assessment of the complete disulphide bridge pattern in the beta-chain of human recombinant follicotropin (betaFSH) was accomplished by integrating classical biochemical methodologies with mass spectrometric procedures. A proteolytic strategy consisting of a double digestion of native betaFSH using the broad-specificity protease subtilisin first, followed by trypsin, was employed. The resulting peptide mixture was directly analysed by FAB-MS, leading to the assignment of the first three disulphide bridges. The remaining S-S bridges were determined by HPLC fractionation of the proteolytic digest followed by ESMS analysis of the individual fractions. The pattern of cysteine couplings in betaFSH was determined as: Cys3-Cys5l, Cys17-Cys66, Cys20-Cys104, Cys28-Cys82, Cys32-Cys84 and Cys87-Cys94, confirming the arrangement inferred from the crystal structure of the homologous betaCG. A subset of the S-S bridge pattern comprising Cys3-Cys51, Cys28-Cys82 and Cys32-Cys84 constitutes a cysteine knot motif similar to that found in the growth factor superfamily.

Amino Acid Sequence↗
PubMed2000

Structural analysis of modified forms of recombinant IFN-beta produced under stress-simulating conditions.

The present study focused on the investigation of the chemical stability of recombinant human interferon-beta (rhIFN-beta) tested in vitro by chemical treatments that simulate stress-induced conditions that may occur during handling, storage or ageing of protein samples. Mild oxidation and/or alkylation of the recombinant protein showed that the four methionines occurring in the interferon displayed different chemical susceptibility in that Met36 and Met117 were fully modified, whereas Met1 showed only little modification and Met62 was completely resistant. Moreover, incubation of rhIFN-beta under alkaline conditions resulted in the formation of a covalent dimeric species stabilised by an intermolecular disulphide bridge involving the free SH group of Cys17 from each polypeptide chain. Analysis of biological activity of the different IFN-beta derivatives showed that rhIFN-beta fully retains its specific activity following mild oxidation treatments whereas reaction with a high concentration of alkylating agents or incubation under alkaline conditions strongly reduce its specific antiviral activity.

Antiviral Agents↗
PubMed1999

Learning of interpolation in 2 and 3 dimensions.

We investigated learning of spatio-temporal interpolation in depth and its relation to spatio-temporal interpolation in two dimensions by means of a vernier discrimination task. Performance improved with training but improvement did not or only partially transfer between opposite directions of motion in depth. Improvement was also at least partly specific for the eye and for the direction of two-dimensional motion used during monocular training. This specificity might explain the apparent specificity of interpolation in three dimensions. Training with stimuli moving in two dimensions increased performance for a stimulus moving in depth. The results indicate that improvement in spatio-temporal interpolation occurs at least partly on a stage preceding stereoscopic vision, and are a rare example for transfer of improvement between different perceptual tasks.

Depth Perception↗
PubMed1996

Structural characterisation of human recombinant glycohormones follitropin, lutropin and choriogonadotropin expressed in Chinese hamster ovary cells.

The alpha and beta chains from human recombinant gonadotropins follitropin, lutropin and choriogonadotropin expressed in CHO cells have been structurally characterised both at the protein and at the carbohydrate level by using advanced mass spectrometric procedures. The three alpha chains share the same amino acid sequence while they display different glycosylation patterns. The oligosaccharide structures detected belong to the complex-type glycans with different degree of sialylation. Partial proteolytic processing occurred at the N-terminus of the follitropin beta chain and at the C-terminus of the lutropin beta chain. The N-linked glycans from the three beta chains were found to contain fucosylated and sialylated diantennary and triantennary complex-type structures. The follitropin beta chain showed the presence of N-acetyllactosamine repeats on the antennae. The overall structure of the recombinant glycohormones corresponds to their natural counterparts with the exception that sulphated terminal glycosylation is missing.

Amino Acid Sequence↗
PubMed1996

NG methyl-L-arginine increases the hyperthermic effects of prostaglandin E1.

The sympathetic firing rate of the nerves innervating interscapular brown adipose tissue (IBAT), IBAT and colonic temperatures (TIBAT and TC) were monitored in urethane-anaesthetized male Sprague-Dawley rats. These variables were measured for a period of 40 min before (baseline values) and 40 min after a 2 mg NG-methyl-L-arginine (NMA) injection plus an intracerebroventricular administration of 500 ng prostaglandin E1 (PGE1) into a lateral cerebral ventricle. No drug was injected in control rats. The results show that NMA enhances the increases in firing rate, TIBAT and TC induced by PGE1. These findings indicate that an inhibitor of nitric oxide synthesis, such as NMA, increases the sympathetic and thermogenic responses to injection of PGE1.

Adipose Tissue, Brown↗
PubMed1996

Lysine acetylsalicylate modifies aphagia and thermogenic changes induced by lateral hypothalamic lesion.

These experiments test the effect of intraperitoneal injection of lysine acetylsalicylate on 1) food intake and 2) the sympathetic and thermogenic changes induced by lesion of the lateral hypothalamus (LH). Food intake, firing rate of the nerves innervating interscapular brown adipose tissue (IBAT), and IBAT and colonic temperatures (TIBAT and TC) were monitored in male Sprague-Dawley rats lesioned in the LH. These variables were measured before and after intraperitoneal injection of lysine acetylsalicylate. The same variables were also monitored in 1) lesioned rats with intraperitoneal administration of saline, 2) sham-lesioned animals with intraperitoneal injection of lysine acetylsalicylate, and 3) sham-lesioned rats with intraperitoneal injection of saline. The results show that lysine acetylsalicylate modifies the aphagia by increasing food intake and also reduces the enhancements in firing rate, TIBAT, and TC induced by LH lesion. These findings suggest that prostaglandin synthesis plays a key role in the control of eating behavior in LH-lesioned rats by acting on the sympathetic and thermogenic changes induced by LH lesion.

Adipose Tissue, Brown↗
PubMed1996

[The use of osteointegrated implants in plastic surgery. Ear reconstruction].

The authors present the case of a 14-year-old patient suffering from first branchial arch syndrome with agenesia of the auricle in which the auricle was reconstructed using osteointegrated implants. The patient had previously undergone numerous attempts at reconstruction using traditional methods, all of which had failed. In order to ensure an accurate preoperative evaluation, the patient was studied using CT with a standard technique and three-dimensional image reconstruction for a qualitative and quantitative evaluation of bone thickness so as to allow the optimal positioning of fixtures. This test also revealed the existence and good degree of development of the middle and internal ear. The Authors then proceeded to implant 4 titanium fixtures into the mastoid process of the temporal bone, three of which were used for fixing the auricle prosthesis and one for the insertion of a bone anchored hearing aid. The epithesis, in soft silicon, was modelled to match the contralateral ear with excellent aesthetic results.

Adolescent↗
PubMed1994

Spatio-temporal interpolation in depth.

Spatio-temporal interpolation creates the impression of motion from a rapid sequence of stationary images by reconstructing the motion path in between the stations actually presented. Thresholds below the diameter of foveal photoreceptors have been obtained with two-dimensional spatio-temporal interpolation. We found that also three-dimensional interpolation, i.e. interpolation in depth, where information from motion detectors tuned to opposite directions in both eyes has to be combined, yields thresholds in the hyperacuity range. The results of parametric experiments favour the interpretation that interpolation occurs at a monocular stage of visual processing, rather than on a stereoscopic stage.

Depth Perception↗
PubMed1990

The amino acid sequence of a ribosome-inactivating protein from Saponaria officinalis seeds.

The complete primary structure of saporin SO-6, a ribosome-inactivating protein extracted from Saponaria officinalis seeds, has been determined. The sequence was reconstructed following purification and analysis of peptides obtained after digestion of the protein with different proteolytic agents. The protein is composed of 253 amino acids, corresponding to a molecular weight of 28,621 Da. Comparison of the primary structure of SO-6 with the sequence deduced from cDNA, shows amino acid substitutions in 11 positions, suggesting a tissue-related genetic variability. When the sequence of saporin is compared to those of two related proteins, ricin A chain and trichosanthin, a low degree of similarity (12%) is found; nevertheless some considerations about structure-function relationships and evolution of RIPs are possible.

Amino Acid Sequence↗