Biomedical subjects
Publications and source records attributed to A De Martino.
Nonlinear transport through interacting single-wall nanotubes containing a few impurities is studied theoretically. Extending the Luttinger liquid theory to incorporate trigonal warping and chirality effects, we derive the current contribution Ie even in the applied voltage V and odd in an orbital magnetic field B, which is nonzero only for chiral tubes and in the presence of interactions.
Some saprobe fungi (Phlebia radiata, Trametes versicolor, Coriolopsis rigida, Pycnoporus cinnabarinus, Fomes sclerodermus or Pleurotus pulmonarius) were able to bioconvert the ethyl acetate fraction (DEAF) and the corresponding aqueous exhausted fraction (EAF) of dry olive mill residue (DOR), reducing their phytotoxicity on Lepidium sativum seeds. Large amount of hydroxytyrosol together with other eight monomeric phenols were found in the native DEAF fraction, which represents a good source of antioxidants. P. radiata, T. versicolor and F. sclerodermus caused an effective phytotoxicity reduction of EAF in the concentration range of 25-3 gl(-1). In particular, in the range between 12.5 and 3 gl(-1), the EAF samples inoculated with P. radiata and F. sclerodermus surprisingly stimulated the germinability of L. sativum, suggesting their use as a potential biofertilizer. This is the first report which showed the bioconversion of the above fractions in shorter time with respect to the previous findings concerning DOR. The possible implications of laccase in the decrease of DEAF and EAF phytotoxicity was also discussed.
We study one-dimensional disordered bosons with strong repulsive interactions. A Bose-Fermi mapping expresses this problem in terms of noninteracting Anderson-localized fermions, whereby known results for the distribution function of the local density of states, the spectral statistics, and density-density correlations can be transferred to this new domain of applicability. We show that disorder destroys bosonic quasi-long-range order by calculating the momentum distribution, and comment on the experimental observability of these predictions in ultracold atomic gases.
We introduce a simple extension of the minority game in which the market rewards contrarian (respectively, trend-following) strategies when it is far from (respectively, close to) efficiency. The model displays a smooth crossover from a regime where contrarians dominate to one where trend-followers dominate. In the intermediate phase, the stationary state is characterized by non-Gaussian features as well as by the formation of sustained trends and bubbles.
A total of 41 metastatic colorectal cancer (CRC) patients received tegafur/uracil (UFT)+leucovorin (LV)+oxaliplatin alternated with UFT/LV+irinotecan. The overall response rate was 58.5% (95% confidence interval, 42.2-73.3%), and the median progression-free survival was 8.8 months. There were no grade 4 toxicities; 12 patients (29%) experienced grade 3 diarrhoea. There were no cases of hand-foot syndrome. This alternating regimen seems to be effective and well tolerated in the first-line treatment of patients with metastatic CRC.
The aim of the study was to evaluate hearing thresholds in 38 patients with rheumatoid arthritis, divided according to disease activity into active (group A, n = 20) and non-active (group B, n = 18) patients. Pure tone audiometry, tympanometry and complete rheumatological assessment were performed. All patients presented poorer auditory thresholds compared with controls. Patients of group A had both air and bone conduction thresholds poorer than group B (although not statistically significant), and most patients of both groups presented an air-bone (a-b) gap. No significant difference in middle ear pressure was noticed between patients and controls. No correlation between hearing impairment and duration of the disease or patients' age was found. The high prevalence of hearing loss in autoimmune diseases supports the importance of audiometric evaluation in such patients. The auditory recovery through middle ear surgery before cranial nerve involvement could be considered in selected patients. Further investigations are needed for a better knowledge of the middle and inner ear involvement in patients with rheumatoid arthritis.
We derive the global phase diagram of a self-gravitating N-body system enclosed in a finite three-dimensional spherical volume V as a function of total energy and angular momentum, employing a microcanonical mean-field approach. At low angular momenta (i.e., for slowly rotating systems) the known collapse from a gas cloud to a single dense cluster is recovered. At high angular momenta, instead, rotational symmetry can be spontaneously broken and rotationally asymmetric structures (double clusters) appear.
A theoretical description of electron spin resonance (ESR) in 1D interacting metals is given, with primary emphasis on carbon nanotubes. The spin-orbit coupling is derived, and the resulting ESR spectrum is analyzed using a low-energy field theory. Drastic differences in the ESR spectra of single-wall and multiwall nanotubes are found. For single-wall tubes, the predicted double peak spectrum is linked to spin-charge separation. For multiwall tubes, a single narrow asymmetric peak is expected.
BACKGROUND: Personal experience about treatment of anastomotic leakage in low anterior resection of the rectum by using human fibrin adhesive "Tissucol" is reported. METHODS: Eight cases of anastomotic leakage treated with using human fibrin adhesive "Tissucol", are analyzed in a retrospective study. Patients had three/six months-one year follow up. Treatment with human fibrin adhesive "Tissucol" was performed in our Endoscopic ambulatory. Six cases had either an immediate resolution or an ambulatorial follow-up; in 2 cases only, general complications forced to a prolonged hospital stay. The study concerns 58 patients subjected to low anterior resection of the rectum and endoscopic treatment of 8/58 patients with anastomotic leakage. Fistulas were sealed with human fibrin adhesive "Tissucol" by using flexible endoscope. Anastomotic leakage identification leakage was made and low anterior resection of the rectum and sealing with human fibrin adhesive "Tissucol" were performed. RESULTS: Complete sealing of fistula and rectum patent. CONCLUSIONS: The excellent results obtained with this non invasive and fast treatment, easily practicable even in ambulatorial regimen, lead the authors to consider it effective and as first-choice treatment of this dangerous complication. The cost/benefit ratio is favorable if compared with the long hospital stay required for other treatments, which also present loaded high morbidity and mortality.
Copper plays a key role in brain development, function and survival. Alteration of its homeostasis is suggested to be an aetiological factor in several neurodegenerative diseases. However, the molecular mechanisms relating copper to neurodegeneration are still unknown. In the present report, using morphological analyses of brain sections of mottled/brindled mutant (Mo(br/y)) mice, the animal model of the human genetic copper deficiency associated with neurodegeneration (Menkes' disease), we demonstrated that a high degree of apoptotic cells is present in the neocortex and in the hippocampus. Biochemical characterisation revealed decreased levels of copper content and of the activity of the mitochondrial copper-dependent enzyme cytochrome c oxidase. Copper, zinc-superoxide dismutase activity also shows a slight decrease, while no change was observed for glutathione content. Lower levels of ATP were also found, indicative of a copper-dependent impairment of energy metabolism. Changes appear to be specific for the brain, since no alterations in the activity of liver enzymes were found, although the level of copper was strongly decreased. We also tested biochemical factors involved in cell commitment to apoptosis. The expression of the anti-apoptotic protein Bcl-2, which plays a fundamental role in brain development and morphogenesis, was dramatically decreased and the levels of cytochrome c released from mitochondria into the cytosol were significantly increased. On the basis of these findings, we propose that down-regulation of Bcl-2 can cause neurodegeneration triggered by mitochondrial damage due to copper depletion during brain development in Mo(br/y) mice.
The c-erbB2 gene has been found to be amplified in a number of human adenocarcinomas, leading to elevated levels of expression of its encoded product, p185. Mutations in the p53 gene are also common in colorectal carcinomas, brain tumours, leukaemia and lymphomas. In this study, p185 and p53 overexpression was analyzed in colorectal adenomas (22 tubular adenomas and 2 tubulo-villous adenomas) and moderately differentiated adenocarcinomas (n = 22) in order to determine whether there was a relationship between these two proteins. The proteins are encoded by two genes located in the same chromosome. p185 and p53 expression was determined on tissue sections by immunohistochemical staining procedure. Expression of p185 was significantly higher (p < 0.01) in preneoplastic lesions (95.8% of cases) than colorectal cancer (63.6% of cases). p53 showed an inverse pattern to p185, being expressed in 58.3% of benign lesions and 72.7% of adenocarcinomas. These results confirm that p185 overexpression is associated with the early stages of colorectal cancer, whereas p53 is associated with more advanced stages. Although there was no correlation between p185 and p53 expression in premalignant lesions and adenocarcinomas, these two proteins have an important role in the adenoma-carcinoma sequence.
SH-SY5Y cells transfected with the enzymatically inactive Cu,Zn superoxide dismutase mutant H46R were more resistant to S-nitrosoglutathione (GSNO)-induced apoptosis. Cytochrome c release from mitochondria, caspase 3 activation, p53 up-regulation, p21 cleavage and Bcl-2 modulation, all involved in the apoptotic process, were significantly less altered with respect to untransfected cells. The H46R resistance to NO was associated with a higher content of reduced glutathione (GSH) and was abolished by blockage of glutathione synthesis. On the other hand, H46R cells were as sensitive as SH-SY5Y cells to puromycin-induced apoptosis; furthermore, they were more susceptible to apoptosis elicited by the superoxide-generating drug paraquat and to cell necrosis provoked by t-butyl hydroperoxide. These results confirm that the level of superoxide dismutase activity is fundamental for protecting cells against oxygen free radical challenge. Its impairment is not detrimental to cells exposed to NO, as long as the overall reducing power represented by GSH is assured. These results are relevant to explain a milder progression of the familial amyotrophic lateral sclerosis disease when associated with the H46R mutation.
BACKGROUND: Limbs phlebostatic ulcers are in many cases associated with perforator reflux veins often caused by post-thromboflebitis syndrome. The origin operation consisting in perforating vein interruption, described by Linton in 1938, allowed high quality exposition of these vessels and gave successful therapeutic results only affected by complications which prolonged hospitalisation. The most unfavorable prognostic factor was the need of performing an incision in skin sites affected by dermo-hypodermic degeneration induced by phlebopathy which inhibits post-surgery cicatrization. The therapeutic importance of reflux perforator vein interruption induced vascular surgeons to improve various procedures not affected by post-surgery complications and able to excise as much incontinent vessels as possible. METHODS: By video-surgery and new surgery tools nowadays available, the Subfascial Endoscopic Perforating Veins Surgery (SEPS) was established as a feasible and valuable method. At present, there are many surgical techniques differing from each other for the tools and the subneurotic compartement from which the perforating veins start. The results obtained from 45 SEPS procedures performed on 45 patients presenting lymphodermatosclerosis or venous ulcers caused by chronic venous insufficiency have been retrospectively evaluated. RESULTS: Thirty-six patients reached ulcer healing within 4 weeks after the operation; 7 ulcers healed over a 2 month time, while for 2 patients no clinical improvement has been recorded yet. CONCLUSIONS: SEPS is a valid alternative to the Linton procedure and provides remarkable advantages both in economic and clinical terms since it yields a more rapid lesions healing of small incisions which makes it one of the most minimally invasive surgical technique.
BACKGROUND: This study is aimed at contributing to defining a correct therapeutic management of pancreatic pseudocysts (PPCs): indications for treatment, operative timing and technical approach. METHODS: A retrospective analysis of 28 patients affected by PPC, 22 males (78.5%) and 6 females (21.5%), with a mean age of 52 years (range 17-76) has been performed. The diagnosis was realised by clinical assessment and US (ultrasonography) or CT (computerized tomography) scanning. The treatment consisted in surgical drainage (internal or external) or percutaneous drainage with US guidance: the cystojejunostomy with a Roux-en-Y loop was the first choice technique. RESULTS: Twenty-two patients (78.5%) under-went a surgical procedure: 19 cystojejunostomies with a Roux-en-Y loop and 3 external drainages. The mean interval between acute pancreatic event and elective surgery was 9 weeks (range 5-21). Perioperative morbidity and mortality was respectively 22.7% (5/22) and 13.6% (3/22). In 4 cases a percutaneous drainage with US-guidance, without morbidity and mortality was performed, but 2 patients required a successive surgical operation for lack of resolution of the PPC. The last 2 patients of this series recovered spontaneously. CONCLUSIONS: Currently the cystojejunostomy with a Roux-en-Y loop remains the first choice technique for an elective and definitive treatment of PPCs: other techniques (endoscopic internal drainage, surgical or percutaneous external drainage) should be limited to complicated PPCs or to high surgical risk patients. A waiting period of 4-6 weeks following the acute pancreatic event is considered the minimal time necessary before the elective treatment.
Nitric oxide (NO) challenge to human neuroblastoma cells (SH-SY5Y) ultimately results in apoptosis. Tumor suppressor protein p53 and cell cycle inhibitor p21 accumulate as an early sign of S-nitrosoglutathione-mediated toxicity. Cytochrome c release from mitochondria and caspase 3 activation also occurred. Cells transfected with either wild type (WT) or mutant (G93A) Cu, Zn-superoxide dismutase (Cu,Zn-SOD) produced comparable amounts of nitrite/nitrate but showed different degree of apoptosis. G93A cells were the most affected and WT cells the most protected; however, Cu, Zn-SOD content of these two cell lines was 2-fold the SH-SY5Y cells under both resting and treated conditions. We linked decreased susceptibility of the WT cells to higher and more stable Bcl-2 and decreased reactive oxygen species. Conversely, we linked G93A susceptibility to increased reactive oxygen species production since simultaneous administration of S-nitrosoglutathione and copper chelators protects from apoptosis. Furthermore, G93A cells showed a significant decrease of Bcl-2 expression and, as target of NO-derived radicals, showed lower cytochrome c oxidase activity. These results demonstrate that resistance to NO-mediated apoptosis is strictly related to the level and integrity of Cu,Zn-SOD and that the balance between reactive nitrogen and reactive oxygen species regulates neuroblastoma apoptosis.
The apical uptake of 64CuCl2 was investigated in human differentiated intestinal Caco-2 cells grown on permeable supports. At pH 6.0 in the apical compartment, the uptake of copper was linear over the first 6 min and between 10 and 80 microM CuCl2 exhibited non-saturable transport kinetics. In addition, copper uptake was energy-independent, affected by the valency state of copper, preferring Cu(II) over Cu(I), and not influenced by high (10 mM) extracellular calcium. The intracellular distribution of copper was investigated by FPLC at different times of uptake ('pulse') and of 'chase'. Intracellular copper initially bound predominantly to low molecular weight components (i.e., glutathione). and subsequently shifted to higher molecular weight components such as metallothionein and Cu,Zn superoxide dismutase.
Accessory light-harvesting complexes (LHCFs) were isolated from the brown alga Laminaria saccharina. Complexes specifically associated with photosystem I or II are identical with each other with respect to molecular mass, isoelectric point and behavior on anion-exchange chromatography or non-denaturing isoelectric focusing. The purified complexes also have similar pigment composition and spectroscopic properties. It is concluded that LHC antennae associated with photosystem I or II cannot be distinguished biochemically. After screening of genomic and cDNA libraries produced from L. saccharina sporophytes, six lhcf genes were isolated. Sequence analysis of these lhcf genes showed a high level of homology between the encoded polypeptides. Comparisons with coding sequences of lhcf genes from Macrocystis pyrifera and expressed sequence tags from Laminaria digitata (two other Laminariales) indicated that these proteins are probably very similar in all brown algae. Another feature common to the lhcf genes characterized was the presence of an intron in the coding region corresponding to the plastid-targeting presequence. The sequence similarity extended to the 5' and 3' UTRs of several genes. In spite of the common origin of the chloroplasts, no light-regulating elements involved in the expression of the genes encoding the higher-plant light-harvesting proteins has been found in the UTRs.
BACKGROUND: Platelet-activating factor (PAF), a phospholipid mediator of inflammation, may induce an enhanced size- and charge-dependent glomerular permeability in experimental animals. Studies on the role of PAF in enhanced glomerular permeability in the early phase of diabetic nephropathy are still lacking. METHODS: We evaluated the intravascular levels of PAF and its main catabolic enzyme, the PAF-specific plasma acetyl-hydrolase (PAF-AH), in basal conditions and after exercise, in normo- or micro-albuminuric insulin-dependent diabetic (IDD) patients and in normal subjects. RESULTS: The results obtained indicate that the concentration of PAF in whole blood was significantly enhanced in basal conditions, during and after exercise in all microalbuminuric IDD patients, but not in normoalbuminuric IDD or in control subjects. The increased concentration of PAF did not correlate with changes in the activity of PAF-AH, suggesting an enhanced production rather than a decreased catabolism of PAF. CONCLUSIONS: These results indicate an association between increased production of PAF and enhanced glomerular permeability in microalbuminuric IDD patients.