Recanalization of the Native Artery in Patients with Bypass Failure

Our objective was to evaluate the possible role of endovascular recanalization of occluded native artery after a failed bypass graft in the case of either acute or chronic limb-threatening ischemia otherwise leading to amputation. In a single-center retrospective clinical analysis, from January 2004 to March 2007 we collected 31 consecutive high-surgical-risk patients (32 limbs) with critical limb ischemia following late ([30 days after surgery) failure of open surgery bypass graft reconstruction. All patients deemed unfit for surgery underwent tentative endovascular recanalization of the native occluded arterial tract. The mean follow-up period was 24 (range, 6–42) months. Technical success was achieved in 30 (93.7%) of 32 limbs. The cumulative primary assisted patency calculated by Kaplan–Meyer analysis was 92% and 88%, respectively, at 12 and 24 months. The limb salvage rate approached 90% at 30 months. In conclusion, our experience shows the feasibility of occluded native artery endovascular recanalization after a failed bypass graft, with optimal results in terms of midterm arterial patency and limb salvage. Our opinion is that successful recanalization of the arterial tract previously considered unsuitable for endovascular approach is allowed by improved competency and experience of vascular specialists, as well as the advances made in catheter and guidewire technology. This group of patients would previously have been relegated to repeat bypass grafts, with their inherently inferior patency and recognized added technical demands. We recognize previous surgical native artery disconnection and lack of pedal runoff to be the main cause of technical failure. Keywords Native artery Bypass failure Endovascular recanalizatio

Role of IGF1 and IGF1/VEGF on Human Mesenchymal Stromal Cells in Bone Healing: Two Sources and Two Fates.

In the repair of skeletal defects one of the major obstacles still remains an efficient vascularization of engineered scaffolds. We have examined the ability of insulin growth factor-1, alone or in association with vascular endothelial growth factor, to modulate the osteoblastic or endothelial commitment of periosteum-derived progenitor cells (PDPCs) and skin-derived multipotent stromal cells (S-MSCs). A selected gene panel for endothelial and osteoblastic differentiation as well as genes that can affect MAPK and PI3K/AKT signaling pathways were investigated. Moreover, gene expression profile of Sox2, Oct4, and Nanog transcription factors was assessed. Our results showed that under growth factor stimulation PDPCs are induced toward an osteoblastic differentiation, while S-MSCs seem to move along an endothelial phenotype. This different commitment seems to be linked to a diverse MAPK or PI3K/AKT signaling pathway activation. The analysis of genes for stemness evidenced that at least in PDPCs multipotency and differentiation could coexist. These results open interesting perspective for the development of innovative bone tissue engineering approaches based on a good network of angiogenesis and osteogenesis processes

Passive Margin evolution and control on natural gas leakage in the Orange Basin South Africa

Throughout exploration Block 2 of the Orange Basin offshore the South African continental margin, different natural gas leakage features and the relationship between natural gas leakage with structural and stratigraphic elements were studied. This study also quantifies liquid/gas hydrocarbon generation, migration and seepage dynamics through the post-rift history of the basin. The interpretation of seismic data reveals two mega-sequences: Cretaceous and Cenozoic that are subdivided by major stratigraphic unconformities into 5 and 2 sub-units, respectively. The basin is also divided into 2 structural domains: 1. an extensional domain characterized by basinward dipping listric normal faults rooted at the Cenomanian/Turonian level identified between 500 to 1500 m of present-day depth, 2. a compressional domain that accommodates the up-dip extension on the lower slope, and which is characterized by landward dipping thrust faults. One hundred and thirteen observed gas chimneys are identified and classified into .stratigraphically-controlled (sa-c) and structurally-controlled (s-c) chimneys. The ratio of s-c versus s-ac chimneys is estimated as 2:5, which suggest a strong stratigraphic control on natural gas leakage. The chimneys either terminate at the seafloor where active leaking gas is manifested by pockmarks, or are sealed within the Miocene (14 Ma) sequence as paleo-pockmarks. The s-c chimneys are located along the normal faults in the extensional domain, and terminate as seafloor mounds up to 1500 m in diameter and with heights between 10 to 50 m. The sa-c pockmarks range between 100 to 400 m in diameter, and are linked to stratigraphic onlaps and pinch-outs within the Aptian sequence. Several giant chimneys, with diameters of more than 7 km, are also identified. At least one of these displays apparent internal gravitational collap.se structures. Bright spots indicative of gas presence within these large chimneys were identified, but there is no evidence of acoustic turbidity or seismic pull-downs within these large structures. This suggests the giant chimneys are inactive paleo-gas-escape structures. Modelling suggests that gas from the lower Aptian and the Barremian source rocks migrates laterally-updip to the proximal parts of the basin where it accumulates beneath the Cenomanian/Turonian sequence that acts as a regional seal. Across the shelf-break and the upper slope, chimneys and pockmarks are fed from younger Cenomanian/Turonian source rocks. The migration model also indicates that fluids are about 24 times more likely to flow out of the study area than to be preserved within it. Since methane gas escaping across the sea floor into the exosphere (combined hydrosphere and atmosphere) may contribute to Earth s climate fluctuations, and because escaping gas must have been cut off when at least half of identified s-c chimneys were sealed within the Mioeene .sequenee, deerease of gas escape along the southern African continental margin may have to be factored into global Neogene cooling models

Distribution and origin of natural gas leakage in the Colorado Basin, offshore Argentina Margin, South America : seismic interpretation and 3D basin modelling

The detailed analysis of a dense 2D seismic reflection dataset and data from 8 exploration wells, allowed us to identify, map out and characterize possible indications of past and present-day hydrocarbon leakage (i.e. gas chimneys, gas pockets, and seafloor mounds and pockmarks) on the continental shelf and slope of the Colorado Basin, offshore Argentina, where Permian, Jurassic and Early Cretaceous source rocks are potentially present and may be currently mature. Identified gas leakage features, developed both in the syn-rift and post-rift successions, were also analysed in relation to the structural the stratigraphic elements of the basin. A family of seabed pockmarks, located close to an array of submarine channels, was identified on the distal slope of the basin. These pockmarks are overlying a series of sub-vertical to vertical seismic chimneys in the subsurface. A calibrated basin-wide 3D petroleum system model comprising generation and migration of hydrocarbons was carried out and compared with the observations from the seismic analysis. Preliminary results from this model indicate that although synrift and early Cretaceous source rock (SR) intervals may be depleted in the central areas of the basin, an active kitchen from the Aptian SR may be present below the slope areas. Hydrocarbon migration pathways predicted by the 3D model (Hybrid method) coincide with the interpreted seismic chimneys underlying the observed seabed slope pockmarks. Hence, our results indicate that thermogenic gas may be currently generated in the distal slope of the basin from mature early post-rift source rocks within the Early Cretaceous (Aptian) sequences and migrates vertically, due to seal failure, through the stratigraphic column. This migrating thermogenic gas is feeding the seafloor pockmarks identified in the distal slope of the basin, although up-dip lateral migration along stratigraphic layers to the more proximal slope areas cannot be ruled out. The present work represents the first published study integrating detailed seismic analysis and 3D basin modelling linking observed gas-leakage indicators and associated seepage pathways, to their relative abundance, distribution and feeding systems offshore Argentina's continental margin

Hospital Organization and Importance of an Interventional Radiology Inpatient Admitting Service:Italian Single-Center 3-year Experience

In June 2005 a Complex Operating Unit of Interventional Radiology (COUIR), consisting of an outpatient visit service, an inpatient admitting service with four beds, and a day-hospital service with four beds was installed at our department. Between June 2005 and May 2008, 1772 and 861 well-screened elective patients were admitted to the inpatient ward of the COUIR and to the Internal Medicine Unit (IMU) or Surgery Unit (SU) of our hospital, respectively, and treated with IR procedures. For elective patients admitted to the COUIR’s inpatient ward, hospital stays were significantly shorter and differences between reimbursements and costs were significantly higher for almost all IR procedures compared to those for patients admitted to the IMU and SU (Student’s t-test for unpaired data, p\0.05). The results of the 3-year activity show that the activation of a COUIR with an inpatient admitting service, and the better organization of the patient pathway that came with it, evidenced more efficient use of resources, with the possibility for the hospital to save money and obtain positive margins (differences between reimbursements and costs). During 3 years of activity, the inpatient admitting service of our COUIR yielded a positive difference between reimbursements and effective costs of €1,009,095.35. The creation of an inpatient IR service and the admission of well-screened elective patients allowed short hospitalization times, reduction of waiting lists, and a positive economic outcome. Keywords Inpatients Hospitalization Costs Reimbursement

Carotid artery stenting: a single-centre experience with up to 8 years' follow-up

Carotid artery stenting (CAS) may be an alternative to surgical endoarterectomy not only in high-risk patients. We report results in the endovascular treatment of carotid artery disease with up to 8 years' follow-up. In this retrospective study, we analysed data from 853 consecutive patients (946 arteries) treated for carotid artery stenosis between April 1999 and March 2007; 491 (52%) arteries were symptomatic and 455(48%) were asymptomatic. Preprocedural evaluation of the patients was performed with echo Doppler, magnetic resonance angiography (MRA) or computed tomographic angiography (CTA) and a neurological examination. A cerebral protection device was used in 879 (92.9%) procedures. Anti-platelet therapy was administered before and after the procedure. All patients were included in a follow-up of up to 8 years. Technical success was achieved in 943 (99.6%) lesions. At 30 days, there was a 0.21% (n = 2) death rate, a 0.42% major stroke rate, a 1.69% minor stroke/transient ischaemic attack (TIA) rate and a combined 2.32% TIA/stroke and death rate. During follow-up, echo Doppler evidenced restenosis in 39 (4.85%) cases; of these, only five, presenting restenosis > 80%, were treated with an endovascular reintervention. At the long-term follow-up, two strokes (0.23%) were reported, which both occurred within the first 2 years. In our experience, carotid artery stenting seems to be a safe and effective treatment, providing satisfactory long-term clinical results

A proteomics approach to the study of bleomycin- induced lung fibrosis

Idiopathic pulmonary fibrosis (IPF) is the most severe lung fibrotic form and very few pharmacological therapies are available at present. Key events in the onset of the disease are the activation of fibroblasts to myofibroblasts and the production and release of extracellular matrix (ECM) and molecular factors. Primary murine lung fibroblasts were isolated and their activation induced by Bleomycin (BLM) treatment. Extracellular Vesicles (EV) were isolated and protein extracted. Released soluble proteins (Secretome) and EV-derived proteins were reduced, alkylated and trypsin digested. A nano-LC-MS/MS SWATHTM approach was used for the proteomics analyses. Specific proteins with a putative role in the transition from physiological to fibrotic conditions, such as several matrix metalloproteinases (MMPs), osteopontin (OPN), chitinase-3-like protein1 (CHI3L1) and CD44 resulted differentially released from BLM-treated fibroblasts as compared with untreated lung fibroblasts. Our results provide further understanding of the pathophysiological features of lung fibrosis, and suggest specific target for pharmacological treatments

Adult mesenchymal stem cells for bone and cartilage engineering: effect of scaffold materials

Bone marrow is a useful cell source for skeletal tissue engineering approaches. In vitro differentiation of marrow mesenchymal stem cells (MSCs) to chondrocytes or osteoblasts can be induced by the addition of specific growth factors to the medium. The present study evaluated the behaviour of human MSCs cultured on various scaffolds to determine whether their differentiation can be induced by cell-matrix interactions. MSCs from bone marrow collected from the acetabulum during hip arthroplasty procedures were isolated by cell sorting, expanded and characterised by a flow cytometry system. Cells were grown on three different scaffolds (type I collagen, type I + II collagen and type I collagen + hydroxyapatite membranes) and analysed by histochemistry, immunohistochemistry and spectrophotometry (cell proliferation, alkaline phosphatase activity) at 15 and 30 days. Widely variable cell adhesion and proliferation was observed on the three scaffolds. MSCs grown on type I+II collagen differentiated to cells expressing chondrocyte markers, while those grown on type I collagen + hydroxyapatite differentiated into osteoblast-like cells. The study highlighted that human MSCs grown on different scaffold matrices may display different behaviours in terms of cell proliferation and phenotype expression without growth factor supplementation

Tau-dependent HDAC1 nuclear reduction is associated with altered VGluT1 expression

During AD pathology, Tau protein levels progressively increase from early pathological stages. Tau altered expression causes an unbalance of Tau subcellular localization in the cytosol and in the nuclear compartment leading to synaptic dysfunction, neuronal cell death and neurodegeneration as a consequence. Due to the relevant role of epigenetic remodellers in synaptic activity in physiology and in neurodegeneration, in particular of TRIM28 and HDAC1, we investigated the relationship between Tau and these epigenetic factors. By molecular, imaging and biochemical approaches, here we demonstrate that Tau altered expression in the neuronal cell line SH-SY5y does not alter TRIM28 and HDAC1 expression but it induces a subcellular reduction of HDAC1 in the nuclear compartment. Remarkably, HDAC1 reduced activity modulates the expression of synaptic genes in a way comparable to that observed by Tau increased levels. These results support a competitive relationship between Tau levels and HDAC1 subcellular localization and nuclear activity, indicating a possible mechanism mediating the alternative role of Tau in the pathological alteration of synaptic genes expression