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Biomedical subjects

F Lo Schiavo

Publications and source records attributed to F Lo Schiavo.

At least 19 recordsLinked to original sources
PubMed2004

[Surgical treatment in day surgery of uncertain breast lesions].

AIM: New models of care are proposed to reduce the costs of traditional hospitalization and to improve the utilization of resources in surgery. Day surgery is widely employed in breast surgery. In this study we report the conversion rate and causes in ordinary hospitalization and we identify some contraindications related to breast surgery in day surgery. METHODS: A cohort study was performed on 306 patients operated on between July 1999 and December 2001 for breast lesions with uncertain interpretation at the clinical and/or instrumental examination. Those patients who lived at a distance of less than 50 km from the hospital, had a telephone, a suitable house, direct family support and, if necessary, could benefit from home health care in addition to hospitalization, were considered as eligible to day surgery. The kind of anesthesia and hospital admission were established after clinical, psycho-emotional, and socio-familiar evaluation of the patients by the surgeon and the anesthetist. RESULTS: A total of 250 excisional biopsies and 56 biopsies with a Mammotome were performed. Surgery was performed under local anesthesia in 278 patients and general anesthesia in 28 subjects. Observation exceeding 24 hours was only necessary in 10 patients reporting hypotension syndrome and anxiety. The conversion rate in ordinary hospitalization was 0.3%. Postoperative morbidity was 1%. CONCLUSION: Day surgery is an effective model of care in breast surgery for diagnostic and therapeutic purposes without axillary dissection. A good selection of patients, perfect interdisciplinary collaboration, and an efficient structural organization are necessary to control the complication and conversion rates of traditional hospitalization.

Ambulatory Surgical Procedures↗
PubMed2001

[Central venous catheterization: complications of different placements].

STUDY AIM: The aim of this prospective multicentric non-randomised trial was to report the complications of the central venous catheter insertion with different techniques and to assess the advantages of the low lateral approach to the internal jugular vein, according to the technique originally described by Jernigan et al, with our own modifications. PATIENTS AND METHOD: From January 1993 to August 1997, 2,290 CVC (2,286 by percutaneous puncture and 4 by surgical approach) were placed. The following complications were analysed prospectively: pneumothorax, accidental arterial puncture, more than two punctures of the same vein, necessity to shift to another venous approach, complete failure, malposition of catheter. RESULTS: The veins the most frequently used were internal jugular vein (48.7%), femoral vein (27%) and subclavian vein (24.2%). Internal jugular vein was punctured especially by low lateral approach (75%) and subclavian vein by infraclavicular approach (92%). With these two placements, the rate of pneumothorax was 0% and 3.1% respectively (p < 0.001), the rate of accidental arterial puncture was 1% and 2.7% respectively (p < 0.03) and the rate of more than two consecutive punctures was 3.1% and 6.3% respectively (p < 0.008). CONCLUSION: On our experience, we advocate the low lateral approach to the internal jugular vein as first choice technique for venipuncture in both adults and children for both short and long-term central venous approach, because it is associated to high rate of outcome and to low rate of complications in comparison with other techniques.

Adult↗
PubMed2001

A novel K+ channel expressed in carrot roots with a low susceptibility toward metal ions.

Kdc1 is a novel K+-channel gene cloned from carrot roots, and which is also present in cultured carrot cells. We investigated the characteristics of the ionic current elicited in Xenopus oocytes coinjected with KDC1 (K+-Daucus carota 1) and KAT1 (from Arabidopsis thaliana) RNA. Expressed heteromeric channels displayed inward-rectifying potassium currents whose kinetics, voltage characteristics, and inhibition by metal ions depended on KDC1:KAT1 ratios. At low KDC1:KAT1 ratios, Zn2+ inhibition of heteromeric K+ current was less pronounced compared to homomeric KAT1 channels, while at higher KDC1:KAT1 ratios, the addition of Zn2+ even produced an increase in current. Under the same conditions, the Ni2+ inhibition of the current was also reduced, but no current increase was observed. These effects might be explained by the unusual amino acid composition of the KDC1 protein in terms of histidine residues that are absent in the pore region, but abundant (four per subunit) in the proximity of the pore entrance. Channels like KDC1 could be at least partially responsible for the higher resistance of carrot cells in the presence of metals.

Animals↗
PubMed2000

Temperature-dependent functional expression of a plant K(+) channel in mammalian cells.

The Arabidopsis thaliana potassium channel KAT1 was expressed and characterized in Chinese hamster ovary cells. KAT1-GFP fusion protein was successfully targeted to the plasma membrane and electrophysiological analysis revealed functional expression of KAT1 only in cells cultured at 30 degrees C. The main biophysical characteristics of KAT1 are similar to those described for the channel expressed in other systems. CHO cells represent an advantageous expression system and may be the system of choice to study the expression, assembly, function, and regulation of plant potassium channels in general.

Animals↗
PubMed2000

Identification and characterization of an 18-kilodalton, VAMP-like protein in suspension-cultured carrot cells.

Polyclonal antibodies raised against rat vesicle associated membrane protein-2 (VAMP-2) recognized, in carrot (Daucus carota) microsomes, two major polypeptides of 18 and 30 kD, respectively. A biochemical separation of intracellular membranes by a sucrose density gradient co-localized the two polypeptides as resident in light, dense microsomes, corresponding to the endoplasmic reticulum-enriched fractions. Purification of coated vesicles allowed us to distinguish the subcellular location of the 18-kD polypeptide from that of 30 kD. The 18-kD polypeptide is present in the non-clathrin-coated vesicle peak. Like other VAMPs, the carrot 18-kD polypeptide is proteolyzed by tetanus toxin after separation of coatomers. Amino acid sequence analysis of peptides obtained by digestion of the 18-kD carrot polypeptide with the endoproteinase Asp-N confirms it to be a member of the VAMP family, as is suggested by its molecular weight, vesicular localization, and toxin-induced cleavage.

Amino Acid Sequence↗
PubMed1999

Evidence suggesting protein tyrosine phosphorylation in plants depends on the developmental conditions.

Protein tyrosine phosphorylation plays a central role in a variety of signal transduction pathways regulating animal cell growth and differentiation, but its relevance and role in plants are controversial and still largely unknown. We report here that a large number of proteins from all plant subcellular fractions are recognized by recombinant, highly specific, anti-phosphotyrosine antibodies. Protein tyrosine phosphorylation patterns vary among different adult plant tissues or somatic embryo stages and somatic embryogenesis is blocked in vivo by a cell-permeable tyrosyl-phosphorylation inhibitor, demonstrating the involvement of protein tyrosine phosphorylation in control of specific steps in plant development.

Animals↗
PubMed1996

Characterization of chitinases able to rescue somatic embryos of the temperature-sensitive carrot variant ts 11.

To characterize the acidic endochitinase EP3, able to rescue somatic embryos of the carrot cell line ts11, the enzyme was purified from the medium of wild-type suspension cultures. Peptide sequences, deduced amino acid sequences of corresponding PCR-generated cDNA clones, serological relation and biochemical properties showed that there were at least five closely related chitinases, four of which could be identified as class IV EP3 chitinases with an apparent size of 30 kDa. Two other proteins were identified as a serologically related class I acidic chitinase (DcChitI) of 34 kDa, and a serologically unrelated 29 kDa class II acidic chitinase (DcChitII), respectively. Additional cDNA sequences, Western and Southern analysis showed the presence of a least two, but possibly more, highly homologous class IV EP3 genes in the carrot genome. Two class IV EP3 chitinases were tested and found to be able to increase the number of ts11 globular embryos formed under non-permissive conditions. One of the class IV EP3 chitinases as well as the class I chitinase DcChitI promoted the transition from globular to heart-stage ts11 embryos. The class II endochitinase and a heterologous class IV chitinase from sugar-beet were not active on ts11. This suggests that there are differences in the specificity of chitinases in terms of their effect on plant somatic embryos.

Amino Acid Sequence↗
PubMed1995

On the occurrence of somatic meiosis in embryogenic carrot cell cultures.

During the establishment of an embryogenic cell line from a carrot hypocotyl explant, processes closely resembling meiotic divisions are seen. A microdensitometric analysis revealed that the amount of cellular DNA diminished in the majority of cells to the haploid level. However, the diploid level was re-established in a matter of a few days. The genetic consequences of this segregation were studied by analyzing restriction fragment length polymorphisms (RFLP) and randomly amplified polymorphic DNAs (RAPD). The results showed that the great majority of embryos regenerated from segregants and that different segregants had different genetic constitutions.

Base Sequence↗
PubMed1992

A carrot somatic embryo mutant is rescued by chitinase.

At the nonpermissive temperature, somatic embryogenesis of the temperature-sensitive (ts) carrot cell mutant ts11 does not proceed beyond the globular stage. This developmental arrest can be lifted by the addition of proteins secreted by wild-type cells to the culture medium. From this mixture of secreted proteins, a 32-kD glycoprotein, designated extracellular protein 3 (EP3), that allows completion of somatic embryo development in ts11 at the nonpermissive temperature was purified. On the basis of peptide sequences and biochemical characterization, EP3 was identified as a glycosylated acidic endochitinase. The addition of the 32-kD endochitinase to ts11 embryo cultures at the nonpermissive temperature appeared to promote the formation of a correctly formed embryo protoderm. These results imply that a glycosylated acidic endochitinase has an important function in early plant somatic embryo development.

Amino Acid Sequence↗
PubMed1992

[Preoperative radiotherapy in locally advanced rectal cancer: risks and complications?].

Adjuvant radiotherapy in advanced rectal cancer is currently considered of interest: preoperative radiotherapy in particular seems to provide better results. However, doubts in its use arise from fear of technical difficulties at surgery and increase of complications. In Authors' opinion, though, preoperative radiotherapy associated with perineal omentoplasty represents a real progress in the management of rectal cancer. Preliminary experience supports this feeling.

Adult↗
PubMed1990

A carrot cell variant temperature sensitive for somatic embryogenesis reveals a defect in the glycosylation of extracellular proteins.

The temperature-sensitive carrot cell variant ts11c, arrested in somatic embryogenesis after the globular stage, was characterized. The sensitivity to a shift from 24 degrees C (permissive temperature) to 32 degrees C (non-permissive temperature) is greatest at the globular stage of embryogenesis, while cells proliferating in unorganized fashion and plantlets are not affected. Embryogenesis in ts11c is also arrested at the permissive temperature by replacement of conditioned culture medium with fresh medium. The timing of sensitivity of ts11c to medium replacement coincides with the sensitivity to temperature shift. Both sensitivities are recessive in somatic hybrids between ts11c and wild-type cells. Extracellular glycoproteins synthesized by ts11c at the non-permissive temperature contain much less fucose than those synthesized by the wild type. The glycoproteins synthesized by the variant under non-permissive conditions do not accumulate at the periphery of the embryo, as their wild-type counterparts do, but instead show a diffuse distribution throughout the embryo. The defect in ts11c can be fully complemented by the addition of extracellular wild-type proteins. A revertant of ts11c was isolated that simultaneously reacquired temperature insensitivity and normal glycosylation ability. Collectively, these observations indicate that ts11c is not able to perform proper glycosylation at the non-permissive temperature and suggest that the activity of certain extracellular proteins, essential for the transition of globular to heart stage somatic embryos, depends on the correct modification of their oligosaccharide side-chains.

Biological Transport↗
PubMed1990

Isolation and in vitro translation of mRNA from inflorescences of Parietaria judaica.

The aqueous extract of inflorescences of Parietaria judaica contains an allergen homologous to the major pollen allergen Par o I (14 kD), as shown by radio-allergosorbent test (RAST) inhibition and immunoblot analysis. Poly(A)+ RNA was obtained from inflorescences and was shown to be able to code in vitro for a protein homologous to Par o I with respect to sodium dodecylsulphate polyacrylamide gel electrophoretic mobility and to antigenic specificity as defined by the binding, in affinity chromatography, to solid-phase IgG of rabbit anti-Par o I antisera, and in RAST inhibition, to IgE antibodies of human reaginic serum pool.

Animals↗
PubMed1978

[Regulation of the renin-angiotensin-aldosterone system. Role of the prostaglandins].

PRA (in the supine and erect subject) and urinary sodium before and after acute treatment (100 mg i.m.) and chronic treatment (100 mg per os for 8 days) were examined in two groups of subjects with no signs of cardiovascular or renal disease. It was found that indomethacin, which is a well-known inhibitor of prostaglandin synthesis, reduced PRA levels in basal conditions and as a result of postural stimulation, without causing any appreciable change in urinary sodium. Regulation of the PRA on the part of the renal prostaglandins is postulated and its probable mechanisms discussed.

Adrenal Cortex↗