Silk-ELR co-recombinamer covered stents obtained by electrospinning.

In the field of tissue engineering the choice of materials is of great importance given the possibility to use biocompatible polymers produced by means of biotechnology. A large number of synthetic and natural materials have been used to this purpose and processed into scaffolds using Electrospinning technique. Among materials that could be used for the fabrication of scaffold and degradable membranes, natural polymers such as collagen, elastin or fibroin offer the possibility to design structures strictly similar to the extracellular matrix (ECM). Biotechnology and genetic engineering made possible the advent of a new class of biopolymers called protein-based polymers. One example is represented by the silk-elastin-proteins that combine the elasticity and resilience of elastin with the high tensile strength of silk-fibroin and display engineered bioactive sequences. In this work, we use electrospinning technique to produce a fibrous scaffold made of the co-recombinamer Silk-ELR. Obtained fibres have been characterized from the morphological point of view. Homogeneity and morphology have been explored using Scanning Electron Microscopy. A thorough study regarding the influence of Voltage, flow rate and distance have been carried out to determine the appropriate parameters to obtain the fibrous mats without defects and with a good distribution of diameters. Cytocompatibility has also been in vitro tested. For the first time we use the co-recombinamer Silk-ELR for the fabrication of a 2.5 angioplasty balloon coating. This structure could be useful as a coated scaffold for the regeneration of intima layer of vessels.

Elastin-like-recombinamers multilayered nanofibrous scaffolds for cardiovascular applications.

Coronary angioplasty is the most widely used technique for removing atherosclerotic plaques in blood vessels. The regeneration of the damaged intima layer after this treatment is still one of the major challenges in the field of cardiovascular tissue engineering. Different polymers have been used in scaffold manufacturing in order to improve tissue regeneration. Elastin-mimetic polymers are a new class of molecules that have been synthesized and used to obtain small diameter fibers with specific morphological characteristics. Elastin-like polymers produced by recombinant techniques and called elastin-like recombinamers (ELRs) are particularly promising due to their high degree of functionalization. Generally speaking, ELRs can show more complex molecular designs and a tighter control of their sequence than other chemically synthetized polymers Rodriguez Cabello et al (2009 Polymer 50 5159-69, 2011 Nanomedicine 6 111-22). For the fabrication of small diameter fibers, different ELRs were dissolved in 2,2,2-fluoroethanol (TFE). Dynamic light scattering was used to identify the transition temperature and get a deep characterization of the transition behavior of the recombinamers. In this work, we describe the use of electrospinning technique for the manufacturing of an elastic fibrous scaffold; the obtained fibers were characterized and their cytocompatibility was tested in vitro. A thorough study of the influence of voltage, flow rate and distance was carried out in order to determine the appropriate parameters to obtain fibrous mats without beads and defects. Moreover, using a rotating mandrel, we fabricated a tubular scaffold in which ELRs containing different cell adhesion sequences (mainly REDV and RGD) were collected. The stability of the scaffold was improved by using genipin as a crosslinking agent. Genipin-ELRs crosslinked scaffolds  show a good stability and fiber morphology. Human umbilical vein endothelial cells  were used to assess the in vitro bioactivity of the cell adhesion domains within the backbone of the ELRs.

[Asbestosis and microfiber role]. / Patologia da asbesto e ruolo delle microfibre.

Based on the predominant content of thin and short asbestos fibres in lung and mesothelioma tissues, it was recently stated (2005) that such fibres "appear to contribute to the causation of human malignant mesothelioma". In another study of the same year it was stated that fibres in the order of few microm length and 0.2 microm diameter are the sole able to induce mesothelioma. This scientific conclusions entail some implications from practical point of view. The enormous amount of information gained on asbestos in the last decades is based on the definition of a fibre as an alongated particle with an aspect-ratio of at least 3:1, a diameter < or = 3 microm and a length > or = 5 microm. These parameters were used up today to define occupational and in some case non-occupational limits. In which way can "reference" values be established if all lengths or only fibres shorter than 5 microm are considered? Nowadays we have no answer. Secondly, assuming a prevalent role of such fibres especially in mesothelioma cases, how can reliable estimates of past exposure obtained in a medico-legal context, since they have never been counted? Morever, how might he the employer responsibility assessed since short fibres were not measured by definition pathogenic, and this not measured, nor were there appropriate filtering systems up to the middle of the '80?

New technology for noninvasive brain monitoring: continuous cerebral oximetry.

Although the central nervous system is the primary endpoint of most general anesthetics, it is still the least monitored organ in clinical anesthesiology. In the last decade, technological research has expanded the application of near-infrared spectroscopy to allow continuous, non-invasive, and bedside monitoring of cerebral oxygen saturation (rSO(2)) through the scalp and skull, providing accurate information on the balance between brain oxygen supply and demand. The aim of this review is to provide an overview on relevant technological issues of cerebral oximetry, describe a systematic approach to its use, and summarize current information on its possible impact on our daily practice. We reviewed studies published on peer-reviewed journals about technological development and clinical application of rSO(2) monitoring in different fields of application to clinical practice. Due to the wide patient-to-patient variability of baseline rSO(2) values in each patient the baseline value should be determined before inducing general anesthesia, and cerebral ischemia is related more to the changes from baseline than to the absolute value: a reduction of 20% from baseline is usually accepted as clinical threshold of cerebral ischemia. If baseline rSO(2) is lower than 50% the critical threshold should be reduced to 15%. Routine use of rSO(2) monitoring in patients undergoing cardiac surgery to guide the anesthesia plan has been demonstrated to improve patient outcome and shorten hospital stay. However, rSO(2) monitoring does not seem to provide information accurate enough to indicate the placement of a Javid's shunt during carotid endarterectomy. In patients with neurological pathology or head trauma rSO(2) monitoring has been reported accurate enough in detecting early changes in cerebral blood flow that might result in cerebral ischemia. In aged patients undergoing major abdominal surgery rSO(2) monitoring to guide the anesthesia plan has been reported to reduce the exposition to cerebral ischemia with less effects on cognitive decline and shorter hospital stay. In conclusion several clinical conditions routinely encountered in our daily practice have the potential to disrupt the balance between the brain oxygen supply and demand, exposing to the risk of intraoperative cerebral ischemia. These alterations in brain oxygen balance remain totally undiagnosed if we do not specifically monitor it; while the possibility of monitoring regional cerebral oxygen saturation through a simple and totally non-invasive device has the potential for optimizing our anesthesia plan to the real needs of our main targeted organ: the brain.

Sciatic nerve block with 0.5% levobupivacaine, 0.75% levobupivacaine or 0.75% ropivacaine: a double-blind, randomized comparison.

BACKGROUND AND OBJECTIVE: This prospective, randomized, double-blind study was conducted to evaluate the onset time and duration of sciatic nerve block produced with 0.5% levobupivacaine, 0.75% levobupivacaine and 0.75% ropivacaine. METHODS: Forty-five healthy patients undergoing hallux valgus repair were randomly allocated to receive sciatic nerve block with levobupivacaine 0.5% (n=15), levobupivacaine 0.75% (n=15) or ropivacaine 0.75% 20 mL (n=15). A femoral nerve block was also performed with mepivacaine 2% 15 mL to cover pain related to the thigh tourniquet. A blinded observer recorded the onset time and duration of sciatic nerve block. RESULTS: The median (range) onset time was 5 (5-40) min with 0.75% levobupivacaine, 30 (5-60) min with 0.5% levobupivacaine and 20 (5-50) min with 0.75% ropivacaine (P = 0.02 and P = 0.12, respectively). Mean (25-75 percentiles) first request for pain medication occurred after 13 (11-14) h with 0.75% ropivacaine, 18 (15-19) h with 0.75% levobupivacaine and 16 (13-20) h with 0.5% levobupivacaine (P = 0.002 and P = 0.002, respectively). Rescue tramadol after surgery was required by three patients in the 0.75% levobupivacaine group, eight patients in the 0.5% levobupivacaine group and nine patients in the 0.75% ropivacaine group (P = 0.05). CONCLUSIONS: We conclude that 0.75% levobupivacaine provides a shorter onset time than 0.5% levobupivacaine and a longer duration of postoperative analgesia than both 0.5% levobupivacaine and 0.75% ropivacaine with reduced need for rescue analgesia after surgery.

[Asbestos fibres and reference values]. / Fibre di amianto e V.R.

Biological RV for asbestos implies several problems, due to the difficult interpretation of values obtained from various biological samples (sputum, BALF, lung tissue). Therefore, it seems it advisable to refer to environmental concentrations (ERC), which are not avoidable, since asbestos is an ubiquitous contaminant. On the basis of the available studies the 1 f/L value is usually reported as the most representative, although more recent and reliable studies would indicate lower values, at least for outdoor concentrations, as determined by SEM. However, further studies are needed: standardized methods based on SEM (author's opinion) should be adopted; the accuracy of such technique is sufficient for air concentrations from 0.05-0.1 f L-1 upwards, with the advantage of lower costs and time as compared to TEM.

[Leg ulcer in thalassemia. The pathogenetic aspects and proposed treatment]. / L'ulcera della gamba nella talassemia. Aspetti patogenetici e proposta di trattamento.

A brief examination of the pathogenetic aspects of ulceration of the leg in thalassaemia is presented with a view to establishing the physiopathological bases for appropriate therapy. Reference is made to a personal case and to the excellent results obtained with the treatment employed.

[Our experience with rare primary localizations of hydatidosis. Analysis of etiopathogenetic aspects]. / La nostra esperienza sulle localizzazioni rare primitive della idatidosi. Analisi degli aspetti etiopatogenetici.

The authors relate their experience on seventeen cases of unusual localizations of Echinococcus cyst operated in the last fifteen years. They present a critical analysis of the different pathogenetic theories trying to explain the peripheral localization of the larva. It is made examination of the factors which would consent the passing through of the hepatic and pulmonary filter, the mechanisms that could avoid such filters and the hypothesis referring to the possibility of direct setting up. They dwell quickly on the peculiar pathogenetic aspects of the various observed localizations.

[Echinococcal cyst of the popliteal region. Clinical case]. / Cisti da echinococco della regione poplitea. Caso Clinico.

A rare case of popliteal cyst due to echinococcus is reported. The implications of the hydatid localisation in this site in regard to differential diagnosis are discussed.