295 research outputs found
One-hundred aortic valve replacements in octogenarians: Outcomes and risk factors for early mortality
Background and aim of the study: Today, ageing of the western population is causing aortic valve surgery to be performed in elderly patients with increasing frequency. The study aim was to evaluate surgical outcome in octogenarian patients undergoing aortic valve replacement (AVR). Methods: A total of 100 patients (mean age 82.1 +/- 2.7 years; range: 80-95 years) who underwent AVR over a three-year period was reviewed. Concomitant coronary artery bypass grafting was performed in 34% of cases, and a bioprosthesis was implanted in 80%. The mean logistic EuroSCORE was 13.3%. Results: Operative mortality was 8.0%. In multivariate analysis, a logistic EuroSCORE >= 13.5% (p = 0.02), cross-clamp time >= 75 min (p = 0.02) and postoperative acute renal failure were predictors for in-hospital mortality. Follow up was 100% complete; the mean follow up period was 10.6 months. At one year after surgery, the actuarial survival rate of those patients who survived surgery was 86.1%. Postoperative dyspnea at one month (p = 0.004) was the only predictor of short-term mortality. Conclusion: Age in itself should not contraindicate surgery, and healthcare systems should be prepared to accommodate elderly patients who may require special resources
Video-assisted mitral surgery through a micro-access: A safe and reliable reality in the current era
Background and aim of the study: Minimally invasive mitral valve surgery was introduced into clinical practice during the mid 1990s. The clinical benefits of the technique, namely a reduction of surgical trauma, increased patient comfort and shorter hospital stay, are achieved by using a video-assisted, mini-thoracotomy approach rather than a standard median sternotomy. Herein is described the authors' experience with video-assisted mitral surgery through a micro-access. Methods: Between September 2003 and September 2006, 100 patients (mean age 65.7 years; range: 16-84 years; 29 aged >75 years) underwent video-assisted port-access mitral valve surgery through a 4- to 6-cm anterior mini-thoracotomy. Mitral valve repair was carried out in 36 patients (36%) and mitral valve replacement (MVR) in 64 (64%) for degenerative (n = 54), rheumatic (n = 44), functional (n = 1) or infective disease (n = 1). Redo procedures were performed in 14 patients. Results: Peripheral extra-thoracic cardiopulmonary bypass (CPB) was used in all cases, and Endoclamp occlusion of the ascending aorta in 94%. The median intensive care unit and hospital stays were 20.0 +/- 30.8 h and 7.0 +/- 5.9 days, respectively. Hospital mortality was 4% (n = 4). No patient required conversion to sternotomy. Five patients (5%) underwent minimally invasive surgical revision for bleeding, and one patient (1%) had an early reoperation for MVR during the immediate postoperative course due to failure of a mitral valve repair. There were no perioperative myocardial infarctions, permanent strokes, major vascular complications, or peripheral ischemic events. Among the patients, 63% had no complications at all during the postoperative course, and no wound infections were observed. Conclusion: Video-assisted mitral surgery through a micro-access may be performed safely, at low risk of morbidity and mortality, and with results and quality standards similar to those reported for a sternotomy approach. Of note, older patients may be successfully treated using this technique
Radioligand therapy (RLT) as neoadjuvant treatment for inoperable pancreatic neuroendocrine tumors: a literature review
In the last 10 years, several literature reports supported radioligand therapy (RLT) in neoadjuvant settings for pancreatic neuroendocrine tumors (PanNETs). Indeed, primary tumor shrinkage has been frequently reported following RLT in unresectable or borderline resectable PanNETs. Moreover, RLT-induced intratumoral modifications facilitate surgery, both on primary tumor and metastasis, having a great impact on progression free survival (PFS), overall survival (OS) and quality of life (QoL). However, prospective controlled investigations are necessary to confirm preliminary data and to define the best RLT scheme and the ideal patient that, in a multidisciplinary approach, should be referred to neoadjuvant RLT
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Dreaming Characteristics in Non-Rapid Eye Movement Parasomnia and Idiopathic Rapid Eye Movement Sleep Behaviour Disorder: Similarities and Differences
Background: Speech graph analysis (SGA) of dreams has recently shown promise as an objective and language-invariant diagnostic tool that can aid neuropsychiatric diagnosis. Whilst the notion that dreaming mentations reflect distinct physiologic processes is not new, such studies in patients with sleep disorders remain exceptionally scarce. Here, using SGA and other dream content analyses, we set to investigate structural and thematic differences in morning dream recalls of patients diagnosed with Non-Rapid Eye Movement Parasomnia (NREMP) and Idiopathic REM Sleep Behavior Disorder (iRBD). Methods: A retrospective cross-sectional study of morning dream recalls of iRBD and NREMP patients was undertaken. Traditional dream content analyses, such as Orlinsky and Hall and Van de Castle analyses, were initially conducted. Subsequently, SGA was performed in order to objectively quantify structural speech differences between the dream recalls of the two patient groups. Results: Comparable rate of morning recall of dreams in the sleep laboratory was recorded; 25% of iRBD and 18.35% of NREMP patients. Aggression in dreams was recorded by 28.57% iRBD versus 20.00% in NREMP group. iRBD patients were more likely to recall dreams (iRBD vs NREMP; P = 0.007), but they also had more white dreams, ie having a feeling of having dreamt, but with no memory of it. Visual and quantitative graph speech analyses of iRBD dreams suggested stable sequential structure, reflecting the linearity of the chronological narrative. Conversely, NREMP dream reports displayed more recursive, less stable systems, with significantly higher scores of graph connectivity measures. Conclusion: The findings of our exploratory study suggest that iRBD and NREMP patients may not only differ on what is recalled in their dreams but also, perhaps more strikingly, on how dreams are recalled. It is hoped that future SGA-led dream investigations of larger groups of patients will help discern distinct mechanistic underpinnings and any associated clinical implications
The edge-on protoplanetary disk HH 48 NE I. Modeling the geometry and stellar parameters
Context. Observations of edge-on disks are an important tool for constraining
general protoplanetary disk properties that cannot be determined in any other
way. However, most radiative transfer models cannot simultaneously reproduce
the spectral energy distributions (SEDs) and resolved scattered light and
submillimeter observations of these systems, due to the differences in geometry
and dust properties at different wavelengths. Aims. We simultaneously constrain
the geometry of the edge-on protoplanetary disk HH 48 NE and the
characteristics of the host star. HH 48 NE is part of the JWST early release
science program Ice Age. This work serves as a stepping stone towards a better
understanding of the disk physical structure and icy chemistry in this
particular source. This kind of modeling lays the groundwork for studying other
edge-on sources to be observed with the JWST. Methods. We fit a parameterized
dust model to HH 48 NE by coupling the radiative transfer code RADMC-3D and an
MCMC framework. The dust structure was fitted independently to a compiled SED,
a scattered light image at 0.8 m and an ALMA dust continuum observation
at 890 m. Results. We find that 90% of the dust mass in HH 48 NE is
settled to the disk midplane, less than in average disks, and that the
atmospheric layers of the disk contain exclusively large grains (0.3-10
m). The exclusion of small grains in the upper atmosphere likely has
important consequences for the chemistry due to the deep penetration of
high-energy photons. The addition of a relatively large cavity (ca. 50 au in
radius) is necessary to explain the strong mid-infrared emission, and to fit
the scattered light and continuum observations simultaneously.Comment: 16 pages, 8 figures, accepted for publication in Astronomy &
Astrophysic
NEMO: A Project for a km Underwater Detector for Astrophysical Neutrinos in the Mediterranean Sea
The status of the project is described: the activity on long term
characterization of water optical and oceanographic parameters at the Capo
Passero site candidate for the Mediterranean km neutrino telescope; the
feasibility study; the physics performances and underwater technology for the
km; the activity on NEMO Phase 1, a technological demonstrator that has
been deployed at 2000 m depth 25 km offshore Catania; the realization of an
underwater infrastructure at 3500 m depth at the candidate site (NEMO Phase 2).Comment: Proceeding of ISCRA 2006, Erice 20-27 June 200
Measurement of the atmospheric muon flux with the NEMO Phase-1 detector
The NEMO Collaboration installed and operated an underwater detector
including prototypes of the critical elements of a possible underwater km3
neutrino telescope: a four-floor tower (called Mini-Tower) and a Junction Box.
The detector was developed to test some of the main systems of the km3
detector, including the data transmission, the power distribution, the timing
calibration and the acoustic positioning systems as well as to verify the
capabilities of a single tridimensional detection structure to reconstruct muon
tracks. We present results of the analysis of the data collected with the NEMO
Mini-Tower. The position of photomultiplier tubes (PMTs) is determined through
the acoustic position system. Signals detected with PMTs are used to
reconstruct the tracks of atmospheric muons. The angular distribution of
atmospheric muons was measured and results compared with Monte Carlo
simulations.Comment: Astrop. Phys., accepte
Synchronization in G0/G1 enhances the mitogenic response of cells overexpressing the human insulin receptor A isoform to insulin
Evaluating mitogenic signaling specifically through the human insulin receptor (IR) is relevant for the preclinical safety assessment of developmental insulin analogs. It is known that overexpression of IR sensitizes cells to the mitogenic effects of insulin, but it is essentially unknown how mitogenic responses can be optimized to allow practical use of such recombinant cell lines for preclinical safety testing. We constitutively overexpressed the short isoform of the human insulin receptor (hIR-A, exon 11-negative) in L6 rat skeletal myoblasts. Because the mitogenic effect of growth factors such as insulin is expected to act in G0/G1, promoting S-phase entry, we developed a combined topoinhibition + serum deprivation strategy to explore the effect of G0/G1 synchronization as an independent parameter in the context of serum deprivation, the latter being routinely used to reduce background in mitogenicity assays. G0/G1 synchronization significantly improved the mitogenic responses of L6-hIR cells to insulin, measured by 3H-thymidine incorporation. Comparison with the parental L6 cells using phospho-mitogen-activated protein kinase, phospho-AKT, as well as 3H-thymidine incorporation end points supported that the majority of the mitogenic effect of insulin in L6-hIR cells was mediated by the overexpressed hIR-A. Using the optimized L6-hIR assay, we found that the X-10 insulin analog was more mitogenic than native human insulin, supporting that X-10 exhibits increased mitogenic signaling through the hIR-A. In summary, this study provides the first demonstration that serum deprivation may not be sufficient, and G0/G1 synchronization may be required to obtain optimal responsiveness of hIR-overexpressing cell lines for preclinical safety testing
Bio-psychosocial determinants of time lost from work following non life threatening acute orthopaedic trauma
<p>Abstract</p> <p>Background</p> <p>To determine factors predicting the duration of time away from work following acute orthopaedic non life threatening trauma</p> <p>Methods</p> <p>Prospective cohort study conducted at four hospitals in Victoria, Australia. The cohort comprised 168 patients aged 18-64 years who were working prior to the injury and sustained a range of acute unintentional orthopaedic injuries resulting in hospitalization. Baseline data was obtained by survey and medical record review. Multivariate Cox proportional hazards regression analysis was used to examine the association between potential predictors and the duration of time away from work during the six month study. The study achieved 89% follow-up.</p> <p>Results</p> <p>Of the 168 participants recruited to the study, 68% returned to work during the six month study. Multivariate Cox proportional hazards regression analysis identified that blue collar work, negative pain attitudes with respect to work, high initial pain intensity, injury severity, older age, initial need for surgery, the presence of co-morbid health conditions at study entry and an orthopaedic injury to more than one region were associated with extended duration away from work following the injury. Participants in receipt of compensation who reported high social functioning at two weeks were 2.58 times more likely to have returned to work than similar participants reporting low social functioning. When only those who had returned to work were considered, the participant reported reason for return to work " to fill the day" was a significant predictor of earlier RTW [RR 2.41 (95% C.I 1.35-4.30)] whereas "financial security" and "because they felt able to" did not achieve significance.</p> <p>Conclusions</p> <p>Many injury-related and psycho social factors affect the duration of time away from work following orthopaedic injury. Some of these are potentially modifiable and may be amenable to intervention. Further consideration of the reasons provided by participants for returning to work may provide important opportunities for social marketing approaches designed to alleviate the financial and social burden associated with work disability.</p
Inactivation of class II PI3K-C2 alpha induces leptin resistance, age-dependent insulin resistance and obesity in male mice
AIMS/HYPOTHESIS: While the class I phosphoinositide 3-kinases (PI3Ks) are well-documented positive regulators of metabolism, the involvement of class II PI3K isoforms (PI3K-C2α, -C2β and -C2γ) in metabolic regulation is just emerging. Organismal inactivation of PI3K-C2β increases insulin signalling and sensitivity, whereas PI3K-C2γ inactivation has a negative metabolic impact. In contrast, the role of PI3K-C2α in organismal metabolism remains unexplored. In this study, we investigated whether kinase inactivation of PI3K-C2α affects glucose metabolism in mice. METHODS: We have generated and characterised a mouse line with a constitutive inactivating knock-in (KI) mutation in the kinase domain of the gene encoding PI3K-C2α (Pik3c2a). RESULTS: While homozygosity for kinase-dead PI3K-C2α was embryonic lethal, heterozygous PI3K-C2α KI mice were viable and fertile, with no significant histopathological findings. However, male heterozygous mice showed early onset leptin resistance, with a defect in leptin signalling in the hypothalamus, correlating with a mild, age-dependent obesity, insulin resistance and glucose intolerance. Insulin signalling was unaffected in insulin target tissues of PI3K-C2α KI mice, in contrast to previous reports in which downregulation of PI3K-C2α in cell lines was shown to dampen insulin signalling. Interestingly, no metabolic phenotypes were detected in female PI3K-C2α KI mice at any age. CONCLUSIONS/INTERPRETATION: Our data uncover a sex-dependent role for PI3K-C2α in the modulation of hypothalamic leptin action and systemic glucose homeostasis. ACCESS TO RESEARCH MATERIALS: All reagents are available upon request
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