169 research outputs found
Low-energy electronic properties of clean CaRuO: elusive Landau quasiparticles
We have prepared high-quality epitaxial thin films of CaRuO with residual
resistivity ratios up to 55. Shubnikov-de Haas oscillations in the
magnetoresistance and a temperature dependence in the electrical
resistivity only below 1.5 K, whose coefficient is substantially suppressed in
large magnetic fields, establish CaRuO as a Fermi liquid (FL) with
anomalously low coherence scale. Non-Fermi liquid (NFL) dependence is
found between 2 and 25 K. The high sample quality allows access to the
intrinsic electronic properties via THz spectroscopy. For frequencies below 0.6
THz, the conductivity is Drude-like and can be modeled by FL concepts, while
for higher frequencies non-Drude behavior, inconsistent with FL predictions, is
found. This establishes CaRuO as a prime example of optical NFL behavior in
the THz range.Comment: 12 pages, 21 figures including supplemental materia
Cruise Report Poseidon 229a/b Kolbeinsey Ridge, Akureyri - Reykjavik, 22.05.1997 - 11.06.1997
General Subject of research: Detailed study of the shallow water hydrothermal system around Kolbeinsey and Grimsey island
Ramucirumab in elderly patients with hepatocellular carcinoma and elevated alpha-fetoprotein after sorafenib in REACH and REACH-2
Background & Aims: Limited data on treatment of elderly patients with hepatocellular carcinoma (HCC) increase the unmet need. REACH and REACH-2 were global phase III studies of ramucirumab in patients with HCC after prior sorafenib, where patients with alpha-fetoprotein (AFP) ≥400 ng/mL showed an overall ssurvival (OS) benefit for ramucirumab. These post-hoc analyses examined efficacy and safety of ramucirumab in patients with HCC and baseline AFP ≥ 400 ng/mL by three prespecified age subgroups (<65, ≥65 to <75 and ≥75 years). Methods: Individual patient data were pooled from REACH (baseline AFP ≥400 ng/mL) and REACH-2. Kaplan-Meier and Cox proportional hazards regression methods (stratified by study) assessed OS, progression-free survival (PFS), time to progression (TTP) and patient-reported outcomes (Functional Hepatobiliary System Index-8 [FHSI-8] score). Results: A total of 542 patients (<65 years: n = 302; ≥65 to <75 years: n = 160; ≥75 years: n = 80) showed similar baseline characteristics between ramucirumab and placebo. Older subgroups had higher hepatitis C and steatohepatitis incidences, and lower AFP levels, than the <65 years subgroup. Ramucirumab prolonged OS in patients <65 years (hazard ratio [HR], 0.753; 95% CI 0.581-0.975), ≥65 to <75 years (0.602; 0.419-0.866) and ≥75 years (0.709; 0.420-1.199), PFS and TTP irrespective of age. Ramucirumab showed similar overall safety profiles across subgroups, with a consistent median relative dose intensity ≥97.8%. A trend towards a delay in symptom deterioration in FHSI-8 with ramucirumab was observed in all subgroups. Conclusions: In this post-hoc analysis, ramucirumab showed a survival benefit across age subgroups with a tolerable safety profile, supporting its use in advanced HCC with elevated AFP, irrespective of age, including ≥75 years
Overall survival and objective response in advanced unresectable hepatocellular carcinoma: A subanalysis of the REFLECT study
Background & Aims: Validated surrogate endpoints for overall survival (OS) are important for expediting the clinical study and drug-development processes. Herein, we aimed to validate objective response as an independent predictor of OS in individuals with unresectable hepatocellular carcinoma (HCC) receiving systemic anti-angiogenic therapy. Methods: We investigated the association between objective response (investigator-assessed mRECIST, independent radiologic review [IRR] mRECIST and RECIST v1.1) and OS in REFLECT, a phase III study of lenvatinib vs. sorafenib. We conducted landmark analyses (Simon-Makuch) of OS by objective response at 2, 4, and 6 months after randomization. Results: Median OS was 21.6 months (95% CI 18.6–24.5) for responders (investigator-assessed mRECIST) vs. 11.9 months (95% CI 10.7–12.8) for non-responders (hazard ratio [HR] 0.61; 95% CI 0.49–0.76; p <0.001). Objective response by IRR per mRECIST and RECIST v1.1 supported the association with OS (HR 0.61; 95% CI 0.51–0.72; p <0.001 and HR 0.50; 95% CI 0.39–0.65; p <0.001, respectively). OS was significantly prolonged for responders vs. non-responders (investigator-assessed mRECIST) at the 2-month (HR 0.61; 95% CI 0.49–0.76; p <0.001), 4-month (HR 0.63; 95% CI 0.51–0.80; p <0.001), and 6-month (HR 0.68; 95% CI 0.54–0.86; p <0.001) landmarks. Results were similar when assessed by IRR, with both mRECIST and RECIST v1.1. An exploratory multivariate Cox regression analysis identified objective response by investigator-assessed mRECIST (HR 0.55; 95% CI 0.44–0.68; p <0.0001) and IRR-assessed RECIST v1.1 (HR 0.49; 95% CI, 0.38–0.64; p <0.0001) as independent predictors of OS in individuals with unresectable HCC. Conclusions: Objective response was an independent predictor of OS in individuals with unresectable HCC in REFLECT; additional studies are needed to confirm surrogacy. Participants achieving a complete or partial response by mRECIST or RECIST v1.1 had significantly longer survival vs. those with stable/progressive/non-evaluable disease. ClinicalTrials.gov number: NCT01761266. Impact and implications: This analysis of data taken from a completed clinical trial (REFLECT) looked for any link between objective response and overall survival time in individuals with unresectable HCC receiving anti-angiogenic treatments. Significantly longer median overall survival was found for responders (21.6 months) vs. non-responders (11.9 months). Overall survival was also significantly longer for responders vs. non-responders (based on objective response status at 2, 4, and 6 months) in the landmark analysis. Our results indicate that objective response is an independent predictor of overall survival in this setting, confirming its validity as a rapid marker of efficacy that can be applied in phase II trials; however, further validation is required to determine is validity for other systemic treatments (e.g. immunotherapies), or as a surrogate of overall survival
Regionalisation of trauma care in England
Aims We aimed to determine whether there is evidence of improved patient outcomes in Major Trauma Centres following the regionalisation of trauma care in England.
Patients and Methods An observational study was undertaken using the Trauma Audit and Research Network (TARN), Hospital Episode Statistics (HES) and national death registrations. The outcome measures were indicators of the quality of trauma care, such as treatment by a senior doctor and clinical outcomes, such as mortality in hospital.
Results and Conclusion A total of 20 181 major trauma cases were reported to TARN during the study period, which was 270 days before and after each hospital became a Major Trauma Centre. Following regionalisation of trauma services, all indicators of the quality of care improved, fewer patients required secondary transfer between hospitals and a greater proportion were discharged with a Glasgow Outcome Score of “good recovery”.
In this early post-implementation analysis, there were a number of apparent process improvements (e.g. time to CT) but no differences in either crude or adjusted mortality. The overall number of deaths following trauma in England did not change following the national reconfiguration of trauma services. Evidence from other countries that have regionalised trauma services suggests that further benefits may become apparent after a period of maturing of the trauma system
A Metalloproteinase Secreted by Streptococcus pneumoniae Removes Membrane Mucin MUC16 from the Epithelial Glycocalyx Barrier
The majority of bacterial infections occur across wet-surfaced mucosal epithelia, including those that cover the eye, respiratory tract, gastrointestinal tract and genitourinary tract. The apical surface of all these mucosal epithelia is covered by a heavily glycosylated glycocalyx, a major component of which are membrane-associated mucins (MAMs). MAMs form a barrier that serves as one of the first lines of defense against invading bacteria. While opportunistic bacteria rely on pre-existing defects or wounds to gain entry to epithelia, non opportunistic bacteria, especially the epidemic disease-causing ones, gain access to epithelial cells without evidence of predisposing injury. The molecular mechanisms employed by these non opportunistic pathogens to breach the MAM barrier remain unknown. To test the hypothesis that disease-causing non opportunistic bacteria gain access to the epithelium by removal of MAMs, corneal, conjunctival, and tracheobronchial epithelial cells, cultured to differentiate to express the MAMs, MUCs 1, 4, and 16, were exposed to a non encapsulated, non typeable strain of Streptococcus pneumoniae (SP168), which causes epidemic conjunctivitis. The ability of strain SP168 to induce MAM ectodomain release from epithelia was compared to that of other strains of S. pneumoniae, as well as the opportunistic pathogen Staphylococcus aureus. The experiments reported herein demonstrate that the epidemic disease-causing S. pneumoniae species secretes a metalloproteinase, ZmpC, which selectively induces ectodomain shedding of the MAM MUC16. Furthermore, ZmpC-induced removal of MUC16 from the epithelium leads to loss of the glycocalyx barrier function and enhanced internalization of the bacterium. These data suggest that removal of MAMs by bacterial enzymes may be an important virulence mechanism employed by disease-causing non opportunistic bacteria to gain access to epithelial cells to cause infection
New Mutations in Chronic Lymphocytic Leukemia Identified by Target Enrichment and Deep Sequencing
Chronic lymphocytic leukemia (CLL) is a heterogeneous disease without a well-defined genetic alteration responsible for the onset of the disease. Several lines of evidence coincide in identifying stimulatory and growth signals delivered by B-cell receptor (BCR), and co-receptors together with NFkB pathway, as being the driving force in B-cell survival in CLL. However, the molecular mechanism responsible for this activation has not been identified. Based on the hypothesis that BCR activation may depend on somatic mutations of the BCR and related pathways we have performed a complete mutational screening of 301 selected genes associated with BCR signaling and related pathways using massive parallel sequencing technology in 10 CLL cases. Four mutated genes in coding regions (KRAS, SMARCA2, NFKBIE and PRKD3) have been confirmed by capillary sequencing. In conclusion, this study identifies new genes mutated in CLL, all of them in cases with progressive disease, and demonstrates that next-generation sequencing technologies applied to selected genes or pathways of interest are powerful tools for identifying novel mutational changes
Guidelines for the use of flow cytometry and cell sorting in immunological studies (third edition)
The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical samples with examples of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer-reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state-of-the-art handbook for basic and clinical researchers
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