366 research outputs found
Considerations on the Adoption of Named Data Networking (NDN) in Tactical Environments
Mobile military networks are uniquely challenging to build and maintain, because of their wireless nature and the unfriendliness of the environment, resulting in unreliable and capacity limited performance. Currently, most tactical networks implement TCP/IP, which was designed for fairly stable, infrastructure-based environments, and requires sophisticated and often application-specific extensions to address the challenges of the communication scenario. Information Centric Networking (ICN) is a clean slate networking approach that does not depend on stable connections to retrieve information and naturally provides support for node mobility and delay/disruption tolerant communications - as a result it is particularly interesting for tactical applications. However, despite ICN seems to offer some structural benefits for tactical environments over TCP/IP, a number of challenges including naming, security, performance tuning, etc., still need to be addressed for practical adoption. This document, prepared within NATO IST-161 RTG, evaluates the effectiveness of Named Data Networking (NDN), the de facto standard implementation of ICN, in the context of tactical edge networks and its potential for adoption
A rare case report of an ilio-psoas abscess due to entero-retroperitoneal fistula from gallstones post cholecystectomy
Introduction and importance: This is a novel case of a 50-year-old female presenting with several months of left iliac fossa pain, on a background of a cholecystectomy 5 years prior. The aetiology of her pain was an ilio-psoas abscess secondary to an entero-retroperitoneal gallstone fistula, a condition not previously reported in the literature. Case presentation: CT imaging revealed an abscess superior to the left psoas muscle, with a clear fistula to the small bowel and two calcified stones at the site of the fistula. The patient was managed operatively, with the fistula disconnected and a 5 cm section of small bowel disconnected. Clinical discussion: This is a novel case whereby a left sided iliopsoas abscess occurred due to entero-retroperitoneal fistulation of gallstones several years after the patient underwent laparoscopic cholecystectomy. Gallstone fistulation from within the small bowel does not appear to have previously been documented and the exact pathogenesis is unknown. Conclusion: Gallstones should remain an important, albeit rare, differential diagnosis of small bowel fistulation and abscess formation following cholecystectomy
CXCR4 pos circulating progenitor cells coexpressing monocytic and endothelial markers correlating with fibrotic clinical features are present in the peripheral blood of patients affected by systemic sclerosis
There is still controversy regarding the role of circulating endothelial and
progenitor cells (CECs/CEPs) in the pathogenesis of systemic sclerosis (SSc).
Using a sequential Boolean gating strategy based on a 4-color flow cytometric
protocol, an increased number of CD31(pos)/CD184(pos)(CXCR4)/CD34(pos)/CD45(pos)
and CD31(pos)/CD117(pos) (c-kit-R) /CD34(pos)/ CD45(pos) hematopoietic
circulating progenitor cells (HCPCs) was detected in SSc patients compared with
healthy subjects. In SSc, no circulating mature and progenitor endothelial cells
were observed, while an enhanced generation of erythroid progenitor cells was
found to be correlated with the presence of CD117+ HCPCs. The presence of freshly
detected CXCR4posHCPC was correlated either to the in vitro cultured
spindle-shaped endothelial like cells (SELC) with an endo/myelomonocytic profile
or to SDF-1 and VEGF serum level. These data are related to more fibrotic
clinical features of the disease, thus supporting a possible role of these cells
in fibrosis
Predictive value of hematological and phenotypical parameters on postchemotherapy leukocyte recovery
Background: Grade IV chemotherapy toxicity is defined as absolute neutrophil count <500/μL. The nadir is considered as the lowest neutrophil number following chemotherapy, and generally is not expected before the 7th day from the start of chemotherapy. The usual prophylactic dose of rHu-G-CSF (Filgrastim) is 300 μg/day, starting 24-48 h after chemotherapy until hematological recovery. However, individual patient response is largely variable, so that rHu-G-CSF doses can be different. The aim of this study was to verify if peripheral blood automated flow cytochemistry and flow cytometry analysis may be helpful in predicting the individual response and saving rHu-G-CSF. Methods: During Grade IV neutropenia, blood counts from 30 cancer patients were analyzed daily by ADVIA 120 automated flow cytochemistry analyzer and by Facscalibur flow cytometer till the nadir. "Large unstained cells" (LUCs), myeloperoxidase index (MPXI), blasts, and various cell subpopulations in the peripheral blood were studied. At nadir rHu-G-CSF was started and 81 chemotherapy cycles were analyzed. Cycles were stratified according to their number and to two dose-levels of rHuG-CSF needed to recovery (300-600 vs. 900-1200 μg) and analyzed in relation to mean values of MPXI and mean absolute number of LUCs in the nadir phase. The linear regressions of LUCs % over time in relation to two dose-levels of rHu-G-CSF and uni-multivariate analysis of lymphocyte subpopulations, CD34+ cells, MPXI, and blasts were also performed. Results: In the nadir phase, the increase of MPXI above the upper limit of normality (>10; median 27.7), characterized a slow hematological recovery. MPXI levels were directly related to the cycle number and inversely related to the absolute number of LUCs and CD34 +/CD45+ cells. A faster hematological recovery was associated with a higher LUC increase per day (0.56% vs. 0.25%), higher blast (median 36.7/μL vs. 19.5/μL) and CD34+/CD45+ cell (median 2.2/μL vs. 0.82/μL) counts. Conclusions: Our study showed that some biological indicators such as MPXI, LUCs, blasts, and CD34 +/CD45+ cells may be of clinical relevance in predicting individual hematological response to rHu-G-CSF. Special attention should be paid when nadir MPXI exceeds the upper limit of normality because the hematological recovery may be delayed. © 2009 Clinical Cytometry Society
Year-round variation in the isotopic niche of Scopoli's shearwater (Calonectris diomedea) breeding in contrasting sea regions of the Mediterranean Sea
Top marine predators are key components of marine food webs. Among them, long-distance migratory seabirds, which travel across different marine ecosystems over the year, may experience important year-round changes in terms of oceanographic conditions and availability of trophic resources. We tested whether this was the case in the Scopoli's shearwater (Calonectris diomedea), a trans-equatorial migrant and top predator, by sampling birds breeding in three environmentally different regions of the Mediterranean Sea. The analysis of positional data and stable isotopes (δ1³C and δ15N) of target feathers revealed that birds from the three regions were spatially segregated during the breeding period while they shared non-breeding areas in the Atlantic Ocean. Isotopic baseline levels of N and C (meso-zooplankton) were significantly different among marine regions during breeding. Such variation was reflected at the higher trophic levels of pelagic and demersal fish muscles as well as in shearwater feathers grown in the Mediterranean. δ15N- and δ13C-adjusted values of shearwaters were significantly different among populations suggesting that birds from different breeding areas relied on prey species from different trophic levels. Conversely, the non-breeding spatial and isotopic niches overlapped greatly among the three populations. Shearwater trophic niches during breeding were narrower and segregated compared to the non-breeding period, revealing a high plasticity in trophic resource use. Overall, this study highlights seasonal and region-specific use of trophic resources by Scopoli's shearwater, suggesting a broad trophic plasticity and possibly a high adaptability to environmental changes
Carfilzomib and dexamethasone versus eight cycles of bortezomib and dexamethasone in patients with relapsed or refractory multiple myeloma : an indirect comparison using data from the phase 3 ENDEAVOR and CASTOR trials
Altres ajuts: This analysis and the development of this manuscript were funded by Amgen (Europe) GmbH. Medical writing support, funded by Amgen (Europe) GmbH, was provided by Oxford PharmaGenesis, Oxford, UK. Editorial support was provided by Carine Thual of Amgen (Europe) GmbH.In ENDEAVOR, carfilzomib and dexamethasone (Kd56) demonstrated significant improvement in progression-free survival (PFS) compared with bortezomib and dexamethasone (Vd). Both agents were administered until disease progression; the EU label for Vd, however, stipulates a maximum of eight treatment cycles. Here, matching-adjusted treatment comparison was used to compare efficacy of Kd56 with Vd, if Vd was administered for 8 cycles (Vd-8). Data from ENDEAVOR and CASTOR trials (which compared daratumumab, bortezomib, and dexamethasone with Vd-8) were used. Hazard ratios of PFS were estimated for Vd vs. Vd-8 and Kd vs. Vd-8. For cycles 1-8, risk reduction in PFS for Kd56 vs. Vd-8 was equal to that estimated in ENDEAVOR (HR: 0.53; 95% CI 0.44-0.65). Beyond eight cycles, risk reduction in PFS for Kd56 and Vd-8 was estimated to be 60% (HR: 0.40; 95% CI 0.26-0.63). The analysis suggested that PFS benefit of Kd56 over Vd increases when Vd is given for eight cycles only
Assessment of distribution of CD34 epitope classes in fresh and cryopreserved peripheral blood progenitor cells and acute myeloid leukemic blasts.
So far several reports have described changes in the expression of surface antigens in progenitor cells and blasts following cryopreservation. However, there are no data on the effects of cryopreservation on the expression of the three CD34 epitope classes, and on their relationship with the clonogenic capacity of PBPC collected by leukapheresis.
DESIGN AND METHODS:
In order to analyze the effects of freezing/thawing procedures (Eth 80C storage for 3 months) and use of dimethylsulfoxide (DMSO) on the immunophenotype profile and colony production of peripheral blood progenitor cells (PBPC) in apheresis products derived from 20 patients with stage 0-III non-Hodgkin's lymphoma (nHL), a flow cytometry study was undertaken using different CD34 monoclonal antibodies (MoAbs) capable of recognizing the 3 epitope classes of CD34 molecule (class III: HPCA-2/FITC, HPCA-2/PE, 581/FITC, 581/PE; class II: Q-Bend 10/PE; class I: ICH3/PE, BI3C5-PE, Immu-133-PE). CD34 epitope expression was also analyzed in thawed CD34+ blasts obtained from 14 patients with acute myeloid leukemia (AML), who were analyzed using a larger number (#17) of CD34 epitope class I, II, and III reactive MoAbs.
RESULTS:
Under our experimental conditions it was found that class III and class II CD34 epitopes (differentially resistant to enzymatic cleavage with neuraminidase, chymopapain and glycoprotease) are better preserved than class I epitope Eth sensitive to degradation Eth after cell exposure to cryoprotectant DMSO and the freezing- thawing procedures. Results further showed a concomitant decrease in class I CD34+ counts and in BFU-E colony production. A significant increase in CD34 antigen expression levels (i.e. antibody binding capacity, ABC) by cryopreserved cells stained with CD34 epitope class III, and class II reactive MoAbs was also documented, while no changes after cryopreservation were noted using class I-reactive MoAbs. The slight increase in the percentage of CD34+ cells detected after frozen storage was correlated to a concomitant decrease in the number of more mature myeloid cells (CD15+, CD13+, CD33+). Compared to pre-cryopreservation values, a slight reduction in class I CD34 epitope expression was also found in thawed CD34+ AML blasts.
INTERPRETATION AND CONCLUSIONS:
As far as the reduction of class I CD34 epitope is concerned, it may be hypothesized that the freezing procedure, use of DMSO, and/or lysis methodology may either damage a CD34 subset, or induce distinct alterations of the CD34 glycoprotein, possibly determining a reduction in their immunoreactivity with some CD34 MoAbs. In conclusion, this study has shown that exposure to the cryoprotectant DMSO and the freezing/thawing procedures modifies the distribution of CD34 epitopes as well as the clonogenic capacity of PBPCs from nHL patients, and CD34+ blasts from AML. These findings need to considered when selecting CD34 MoAbs for enumeration and positive selection of stem/progenitor cells for research and clinical purposes
Cascades of shocks in Active Galactic Nuclei and their radiation
We discuss accretion flows on massive black holes in which different elements
of the flow (clumps) have velocities that may differ substantially. We estimate
the consequence of collisions between these clumps as they come close to the
central object and calculate the resulting radiation. We show that this
radiation is similar to that observed in the optical to X-ray spectral domain
in Seyfert galaxies and quasars. We also show that the large scale accretion is
likely to be clumpy when arriving in the active region and that the clumps keep
their identity between collisions.Comment: Accepted in A+A, 8 pages, 2 figure
Prophylactic heparin and risk of orotracheal intubation or death in patients with mild or moderate COVID-19 pneumonia
Prophylactic low molecular weight heparin (pLMWH) is currently recommended in COVID-19 to reduce the risk of coagulopathy. The aim of this study was to evaluate whether the antinflammatory effects of pLMWH could translate in lower rate of clinical progression in patients with COVID-19 pneumonia. Patients admitted to a COVID-hospital in Rome with SARS-CoV-2 infection and mild/moderate pneumonia were retrospectively evaluated. The primary endpoint was the time from hospital admission to orotracheal intubation/death (OTI/death). A total of 449 patients were included: 39% female, median age 63 (IQR, 50–77) years. The estimated probability of OTI/death for patients receiving pLMWH was: 9.5% (95% CI 3.2–26.4) by day 20 in those not receiving pLMWH vs. 10.4% (6.7–15.9) in those exposed to pLMWH; p-value = 0.144. This risk associated with the use of pLMWH appeared to vary by PaO_{2}/FiO_{2} ratio aHR 1.40 (95% CI 0.51–3.79) for patients with an admission PaO_{2}/FiO_{2} ≤ 300 mmHg and 0.27 (0.03–2.18) for those with PaO_{2}/FiO_{2} > 300 mmHg; p-value at interaction test 0.16. pLMWH does not seem to reduce the risk of OTI/death mild/moderate COVID-19 pneumonia, especially when respiratory function had already significantly deteriorated. Data from clinical trials comparing the effect of prophylactic vs. therapeutic dosage of LMWH at various stages of COVID-19 disease are needed
A Major Role for Side-Chain Polyglutamine Hydrogen Bonding in Irreversible Ataxin-3 Aggregation
The protein ataxin-3 consists of an N-terminal globular Josephin domain (JD) and an unstructured C-terminal region containing a stretch of consecutive glutamines that triggers the neurodegenerative disorder spinocerebellar ataxia type 3, when it is expanded beyond a critical threshold. The disease results from misfolding and aggregation, although the pathway and structure of the aggregation intermediates are not fully understood. In order to provide insight into the mechanism of the process, we monitored the aggregation of a normal (AT3Q24) ataxin-3, an expanded (AT3Q55) ataxin-3, and the JD in isolation. We observed that all of them aggregated, although the latter did so at a much slower rate. Furthermore, the expanded AT3Q55 displayed a substantially different behavior with respect to the two other variants in that at the latest stages of the process it was the only one that did the following: i) lost its reactivity towards an anti-oligomer antibody, ii) generated SDS-insoluble aggregates, iii) gave rise to bundles of elongated fibrils, and iv) displayed two additional bands at 1604 and 1656 cm−1 in FTIR spectroscopy. Although these were previously observed in other aggregated polyglutamine proteins, no one has assigned them unambiguously, yet. By H/D exchange experiments we show for the first time that they can be ascribed to glutamine side-chain hydrogen bonding, which is therefore the hallmark of irreversibly SDS-insoluble aggregated protein. FTIR spectra also showed that main-chain intermolecular hydrogen bonding preceded that of glutamine side-chains, which suggests that the former favors the latter by reorganizing backbone geometry
- …