54 research outputs found
Will Jets Identify the Progenitors of Type Ia Supernovae?
We use the fact that a Type Ia supernova has been serendipitously discovered
near the jet of the active galaxy 3C 78 to examine the question of whether jets
can enhance accretion onto white dwarfs. One interesting outcome of such a
jet-induced accretion process is an enhanced rate of novae in the vicinity of
jets. We present results of observations of the jet in M87 which appear to have
indeed discovered 11 novae in close proximity to the jet. We show that a
confirmation of the relation between jets and novae and Type Ia supernovae can
finally identify the elusive progenitors of Type Ia supernovae.Comment: 10 pages, 3 figure
Black hole formation via hypercritical accretion during common envelope evolution
Neutron stars inspiralling into a stellar envelope can accrete at rates
vastly exceeding the Eddington limit if the flow develops pressures high enough
to allow neutrinos to radiate the released gravitational energy. It has been
suggested that this hypercritical mode of accretion leads inevitably to the
formation of stellar mass black holes during common envelope evolution. We
study the hydrodynamics of this flow at large radii (R >> R_ns), and show that
for low Mach number flows, in two dimensions, modest density gradients in the
stellar envelope suffice to produce a hot, advection dominated accretion disk
around the accreting object. The formation of outflows from such a disk is
highly probable, and we discuss the impact of the resultant mass loss and
feedback of energy into the envelope for the survival of the neutron star.
Unless outflows are weaker than those inferred for well observed accreting
systems, we argue that in most cases insufficient accretion occurs to force
collapse to a black hole before the envelope has been ejected. This conclusions
is of interest for black hole formation in general, for some models of gamma
ray bursts, and for predictions of the event rate in future LIGO observations.Comment: ApJ, submitte
Weight Loss Expectations in Obese Patients and Treatment Attrition: An Observational Multicenter Study
Objective: To investigate the influence of weight loss expectations
(expected 1-year BMI loss, dream and maximum
acceptable BMI) on attrition in obese patients seeking treatment.
Research Methods and Procedures: Obese subjects (1785;
1393 women; median age, 46 years; median BMI, 36.7
kg/m2) seeking treatment in 23 medical Italian centers were
evaluated. Baseline diet and weight history, weight loss
expectations, and primary motivation for seeking treatment
(health or improving appearance) were systematically recorded.
Psychiatric distress, binge eating, and body image
dissatisfaction were tested at baseline by self-administered
questionnaires (Symptom Check List-90, Binge Eating
Scale, and Body Uneasiness Test). Attrition and BMI
change at 12 months were prospectively recorded.
Results: At 12 months, 923 of 1785 patients (51.7%) had
discontinued treatment. Compared with continuers, dropouts
had a significantly lower age, a lower age at first
dieting, lower dream BMI, a higher expected 1-year BMI
loss, and a higher weight phobia. At logistic regression
analysis, the strongest predictors of attrition at 12 months
were lower age and higher expected 1-year BMI loss. The
risk of drop-out increased systematically for unit increase in
expected BMI loss at 12 months (hazard ratio, 1.12; 95%
confidence interval, 1.04 to 1.20; p 0.0018). The risk was
particularly elevated in the first 6 months.
Discussion: Baseline weight loss expectations are independent
cognitive predictors of attrition in obese patients entering
a weight-losing program; the higher the expectations,
the higher attrition at 12 months. Unrealistic weight goals
should be tackled at the very beginning of treatment
Effects of bariatric and metabolic surgical procedures on dyslipidemia: a retrospective, observational analysis.
Aim: Obesity and co-existing metabolic comorbidities are associated with increased cardiovascular (CV) morbidity and mortality risks, generally clustered to risk factors such as dyslipidemia. The aim of this study was to evaluate the lipid profile changes in subjects with severe obesity undergoing different procedures of bariatric and metabolic surgery (BMS), sleeve gastrectomy (SG), and Roux-en-Y gastric bypass (RYGB) in a real-world, clinical setting.
Methods: A single-center, retrospective, observational clinical study was performed enrolling patients undergoing BMS. The primary outcome was the change in total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL) cholesterol, and triglycerides.
Results: In total, 123 patients were enrolled (males 25.2% and females 74.8%) with a mean age of 48.2 ± 7.9 years and a mean BMI of 47.0 ± 9.1 kg/m2. All patients were evaluated until 16.9 ± 8.1 months after surgery. Total and HDL cholesterol did not change after surgery, while a significant reduction in triglyceride levels was recorded. Moreover, a rapid decline of both LDL and non-HDL cholesterol among follow-up visits was observed. In particular, significant inverse correlations were found between total cholesterol, LDL cholesterol, non-HDL cholesterol, and triglycerides and the number of months elapsed after bariatric surgery. Similarly, a direct correlation was found considering HDL cholesterol. Moreover, total cholesterol, LDL cholesterol, non-HDL cholesterol, and triglycerides significantly changed among visits after RYGB, while no changes were observed in the SG group. Finally, considering lipid-lowering therapies, the improvement in lipid asset was detected only in non-treated patients.
Conclusion: This study corroborates the knowledge of the improvement in lipid profile with BMS in clinical practice. Together with sustained weight loss, the BMS approach efficiently corrects dyslipidemia, contributing to decreasing the CV risk
Cement augmentation of intertrochanteric fractures stabilisedwith intramedullary nail: operative technique.
The incidence of proximal femoral fractures has substantially risen in the elderly. This rise has been
attributed to an increase in their life span and the underlying poor bone stock and osteoporosis.One of themain
reason for revision surgery, reported to be as high as 19%, is the cut-out of the fixation device at the apex of the
femoral head. Augmentation, facilitated by injecting cement (PMMA) around the apex of the proximal screw
of the fixation device, is considered as a useful method with regard to the increase purchase between the bone
and implant interface.The aim of this study is the description of the cement Augmentation operative technique
for unstable osteoporotic intertrochanteric fractures with 1-2 femoral head screws devices.
La complicanza del cut-out nel trattamento delle fratture pertrocanteriche nell'anziano con osteoporosi, descritta in letteratura con una incidenza variabile dal 9 al 14%, risulta essere un problema attuale in chirurgia ortopedica. La tecnica operatoria dell’Augmentation, intesa come supporto meccanico
della sintesi interna nelle fratture pertrocanteriche, tramite cementazione con pochi millilitri di PMMA all’apice
delle viti cervico-cefaliche, è stato dimostrato, in vitro ed in vivo, essere una sicura e valida metodica
per scongiurare il fenomeno del cut-out
Tibial plateau fractures: compared outcomes between ARIF and ORIF.
The purpose of this study is to compare
arthroscopic assisted reduction internal fixation (ARIF)
treatment with open reduction internal fixation (ORIF)
treatment in patients with tibial plateau fractures. We
studied 100 patients with tibial plateau fractures (54 men
and 46 women) examined by X-rays and CT scans, divided
into 2 groups. Group A with associated meniscus tear was
treated by ARIF technique, while in group B ORIF technique
was used. The follow-up period ranged from 12 to
116 months. The patients were evaluated both clinically
and radiologically according to the Rasmussen and HSS
(The Hospital for Special Surgery knee-rating) scores. In
group A, the average Rasmussen clinical score is
27.62 ± 2.60 (range, 19–30), while in group B is
26.81 ± 2.65 (range, 21–30). HSS score in group A was
76.36 ± 14.19 (range, 38–91) as the average clinical result,
while in group B was 73.12 ± 14.55 (range, 45–91).
According to Rasmussen radiological results, the average
score for group A was 16.56 ± 2.66 (range, 8–18), while in
group B was 15.88 ± 2.71 (range, 10–18). Sixty-nine of
100 patients in our study had associated intra-articular
lesions. We had 5 early complications and 36 late complications.
The study suggests that there are no differences
between ARIF and ORIF treatment in Schatzker type I
fractures. ARIF technique may increase the clinical outcome
in Schatzker type II–III–IV fractures. In Schatzker
type V and VI fractures, ARIF and ORIF techniques have
both poor medium- and long-term results but ARIF
treatment, when indicated, is the best choice for the lower
rate of infections
Clinical evaluation of switching from immediate-release to prolonged-release lithium in bipolar patients, poorly tolerant to lithium immediate-release treatment: A randomized clinical trial
open13Aim: The effect of switching from lithium immediate release (Li-IR) to lithium prolonged release (Li-PR) on lithium-induced tremor after 1 and 12 weeks of treatment was evaluated in a randomized, multicenter, open trial, in bipolar patients from the participating sites with a tremor severity ≥2 (Udvalg for Kliniske Undersøgelser [UKU] rating scale) despite optimal lithium titration. Methods: The primary endpoint was the evaluation of tremor by means of the UKU scale after 1 week of treatment. Secondary endpoints included manic Young Mania Rating Scale (YMRS) and depressive symptoms (Montgomery-Asberg Depression Rating Scale), a global assessment of the patient's status (Clinical Global Impression), polyuria/polydipsia (UKU item 3.8) and patient-reported outcomes. Results: Owing to difficulties in including suitable patients the enrollment phase was closed when 73 patients were randomized. Notwithstanding the lower number of patients, in the modified intention-to-treat population (n = 70) the primary endpoint was statistically significant: tremor improved after 1 week in 62.9% in Li-PR group against 20.0% of patients in Li-IR group (p = .0006; two-tailed Fisher's exact test). The difference remained statistically significant after 4 (p = .0031) and 12 weeks (p = .0128). The same analysis performed in the PP population confirmed these results. Among the secondary endpoints, only the factor convenience of the treatment satisfaction questionnaire showed a statistically significant difference between groups. There were no apparent differences in the safety profile of the two formulations. Conclusions: This study is the first comparative documentation of a potential benefit of the prolonged-release formulation in reducing the symptom tremor, a well-known adverse effect of lithium therapy. Indeed, the study results should be interpreted taking into account the sample size lower than planned.openPelacchi, Federica; Dell'Osso, Liliana; Bondi, Emi; Amore, Mario; Fagiolini, Andrea; Iazzetta, Paolo; Pierucci, Daniela; Gorini, Manuela; Quarchioni, Elisa; Comandini, Alessandro; Salvatori, Enrica; Cattaneo, Agnese; Pompili, MaurizioPelacchi, Federica; Dell'Osso, Liliana; Bondi, Emi; Amore, Mario; Fagiolini, Andrea; Iazzetta, Paolo; Pierucci, Daniela; Gorini, Manuela; Quarchioni, Elisa; Comandini, Alessandro; Salvatori, Enrica; Cattaneo, Agnese; Pompili, Maurizi
Hydrophilicity Matching – A Potential Prerequisite for the Formation of Protein-Protein Complexes in the Cell
A binding event between two proteins typically consists of a diffusional search of binding partners for one another, followed by a specific recognition of the compatible binding sites resulting in the formation of the complex. However, it is unclear how binding partners find each other in the context of the crowded, constantly fluctuating, and interaction-rich cellular environment. Here we examine the non-specific component of protein-protein interactions, which refers to those physicochemical properties of the binding partners that are independent of the exact details of their binding sites, but which can affect their localization or diffusional search for one another. We show that, for a large set of high-resolution experimental 3D structures of binary, transient protein complexes taken from the DOCKGROUND database, the binding partners display a surprising, statistically significant similarity in terms of their total hydration free energies normalized by a size-dependent variable. We hypothesize that colocalization of binding partners, even within individual cellular compartments such as the cytoplasm, may be influenced by their relative hydrophilicity, potentially in response to local hydrophilic gradients
Potential value of a rapid syndromic multiplex PCR for the diagnosis of native and prosthetic joint infections: a real-world evidence study.
Introduction: The BIOFIRE Joint Infection (JI) Panel is a diagnostic tool that uses multiplex-PCR testing to detect microorganisms in synovial fluid specimens from patients suspected of having septic arthritis (SA) on native joints or prosthetic joint infections (PJIs). Methods: A study was conducted across 34 clinical sites in 19 European and Middle Eastern countries from March 2021 to June 2022 to assess the effectiveness of the BIOFIRE JI Panel. Results: A total of 1527 samples were collected from patients suspected of SA or PJI, with an overall agreement of 88.4 % and 85 % respectively between the JI Panel and synovial fluid cultures (SFCs). The JI Panel detected more positive samples and microorganisms than SFC, with a notable difference on Staphylococcus aureus, Streptococcus species, Enterococcus faecalis, Kingella kingae, Neisseria gonorrhoeae, and anaerobic bacteria. The study found that the BIOFIRE JI Panel has a high utility in the real-world clinical setting for suspected SA and PJI, providing diagnostic results in approximately 1 h. The user experience was positive, implying a potential benefit of rapidity of results\u27 turnover in optimising patient management strategies. Conclusion: The study suggests that the BIOFIRE JI Panel could potentially optimise patient management and antimicrobial therapy, thus highlighting its importance in the clinical setting
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