219 research outputs found
Recommended from our members
"Out of the loop": autonomous weapon systems and the law of armed conflict
The introduction of autonomous weapon systems into the âbattlespaceâ will profoundly influence the nature of future warfare. This reality has begun to draw the attention of the international legal community, with increasing calls for an outright ban on the use of autonomous weapons systems in armed conflict. This Article is intended to help infuse granularity and precision into the legal debates surrounding such weapon systems and their future uses. It suggests that whereas some conceivable autonomous weapon systems might be prohibited as a matter of law, the use of others will be unlawful only when employed in a manner that runs contrary to the law of armed conflictâs prescriptive norms governing the âconduct of hostilities.â This Article concludes that an outright ban of autonomous weapon systems is insupportable as a matter of law, policy, and operational good sense. Indeed, proponents of a ban underestimate the extent to which the law of armed conflict, including its customary law aspect, will control autonomous weapon system operations. Some autonomous weapon systems that might be developed would already be unlawful per se under existing customary law, irrespective of any treaty ban. The use of certain others would be severely limited by that law.
Furthermore, an outright ban is premature since no such weapons have even left the drawing board. Critics typically either fail to take account of likely developments in autonomous weapon systems technology or base their analysis on unfounded assumptions about the nature of the systems. From a national security perspective, passing on the opportunity to develop these systems before they are fully understood would be irresponsible. Perhaps even more troubling is the prospect that banning autonomous weapon systems altogether based on speculation as to their future form could forfeit their potential use in a manner that would minimize harm to civilians and civilian objects when compared to non-autonomous weapon systems
Decrease in treatment intensity predicts worse outcome in patients with locally advanced head and neck squamous cell carcinoma undergoing radiochemotherapy
PURPOSE: Radiochemotherapy (RCT) is an effective standard therapy for locally advanced head and neck squamous cell carcinoma (LA-HNSCC). Nonetheless, toxicity is common, with patients often requiring dose modifications. METHODS: To investigate associations of RCT toxicities according to CTCAE version 5.0 and subsequent therapy modifications with short- and long-term treatment outcomes, we studied all 193 patients with HNSCC who received RCT (70Â Gyâ+âplatinum agent) at an academic center between 03/2010 and 04/2018. RESULTS: During RCT, 77 (41%, 95% CI 34-49) patients developed at least oneââ„âgrade 3 toxicity, including seven grade 4 and 3 fatal grade 5 toxicities. The most frequent any-grade toxicities were xerostomia (nâ=â187), stomatitis (nâ=â181), dermatitis (nâ=â174), and leucopenia (nâ=â98). Eleven patients (6%) had their radiotherapy schedule modified (mean radiotherapy dose reductionâ=â12Â Gy), and 120 patients (64%) had chemotherapy modifications (permanent discontinuation: nâ=â67, pause: nâ=â34, dose reduction: nâ=â7, change to other chemotherapy: nâ=â10). Objective response rates to RCT were 55% and 88% in patients with and without radiotherapy modifications (pâ=â0.003), and 84% and 88% in patients with and without chemotherapy modifications (pâ=â0.468), respectively. Five-year progression-free survival estimates were 20% and 50% in patients with and without radiotherapy modifications (pâ=â<â0.001), and 53% and 40% in patients with and without chemotherapy modifications (pâ=â0.88), respectively. CONCLUSIONS: Reductions of radiotherapy dose were associated with impaired long-term outcomes, whereas reductions in chemotherapy intensity were not. This suggests that toxicities during RCT should be primarily managed by modifying chemotherapy rather than radiotherapy
ADAM8 in squamous cell carcinoma of the head and neck: a retrospective study
<p>Abstract</p> <p>Background</p> <p>A disintegrin and metalloproteinase (ADAMs) have been associated with multiple malignancies. ADAMs are involved in cell fusion, cell migration, membrane protein shedding and proteolysis. ADAM8 has been found to be overexpressed in squamous cell carcinomas of the lung. A new study showed that ADAM8 is significantly overexpressed in metastasis of squamous cell carcinomas of the head and neck (HNSCC).</p> <p>Methods</p> <p>We determined ADAM8 levels in the serum of 79 HNSCC patients at the time of diagnosis, in 35 patients 3 months after treatment and in 10 patients 1 year after therapy and compared the results to the sera of 31 healthy volunteers. We also constructed tissue microarrays to detect ADAM8 immunohistochemically in 100 patients. The results were correlated with the survival data of the patients to determine the diagnostic and prognostic value.</p> <p>Results</p> <p>The data demonstrated that patients with high ADAM8 expression in the tumor have worse survival rates. We found that high ADAM8 serum levels correlated with high ADAM8 expression in tumor samples. Soluble ADAM8 levels did not show any prognostic or diagnostic properties.</p> <p>Conclusion</p> <p>In summary ADAM8 expression is a prognostic factor for survival of patients with head and neck squamous cell carcinoma.</p
Multicenter, double-blind, randomized, intraindividual crossover comparison of gadobenate dimeglumine and gadopentetate dimeglumine for MR angiography of peripheral arteries
Purpose: To prospectively compare the image quality and diagnostic performance achieved with doses of gadobenate dimeglumine and gadopentetate dimeglumine of 0.1 mmol per kilogram of body weight in patients undergoing contrast material-enhanced magnetic resonance (MR) angiography of the pelvis, thigh, and lower-leg (excluding foot) for suspected or known peripheral arterial occlusive disease. Materials and Methods: Institutional review board approval was granted from each center and informed written consent was obtained from all patients. Between November 2006 and January 2008, 96 patients (62 men, 34 women;mean age, 63.7 years \ub1 10.4 [standard deviation];range, 39-86 years) underwent two identical examinations at 1.5 T by using three-dimensional spoiled gradient-echo sequences and randomized 0.1-mmol/kg doses of each agent. Images were evaluated on-site for technical adequacy and quality of vessel visualization and offsite by three independent blinded readers for anatomic delineation and detection/exclusion of pathologic features. Comparative diagnostic performance was determined in 31 patients who underwent digital subtraction angiography. Data were analyzed by using the Wilcoxon signed-rank, McNemar, and Wald tests. Interreader agreement was determined by using generalized \u3ba statistics. Differences in quantitative contrast enhancement were assessed and a safety evaluation was performed. Results: Ninety-two patients received both agents. Significantly better performance ( P > .0001; all evaluations) with gadobenate dimeglumine was noted on-site for technical adequacy and vessel visualization quality and offsite for anatomic delineation and detection/exclusion of pathologic features. Contrast enhancement(P 64 .0001) and detection of clinically relevant disease(P 64 .0028) were significantly improved with gadobenate dimeglumine. Interreader agreement for stenosis detection and grading was good to excellent (\u3ba = 0.749 and 0.805, respectively). Mild adverse events were reported for four (six events) and five (eight events) patients after gadobenate dimeglumine and gadopentetate dimeglumine, respectively. Conclusion: Higher-quality vessel visualization, greater contrast enhancement, fewer technical failures, and improved diagnostic performance are obtained with gadobenate dimeglumine, relative to gadopentetate dimeglumine, when compared intraindividually at 0.1-mmol/kg doses in patients undergoing contrast-enhanced MR angiography for suspected peripheral arterial occlusive disease
Increased betulinic acid induced cytotoxicity and radiosensitivity in glioma cells under hypoxic conditions
<p>Abstract</p> <p>Background</p> <p>Betulinic acid (BA) is a novel antineoplastic agent under evaluation for tumor therapy. Because of the selective cytotoxic effects of BA in tumor cells (including gliomas), the combination of this agent with conservative therapies (such as radiotherapy and chemotherapy) may be useful. Previously, the combination of BA with irradiation under hypoxic conditions had never been studied.</p> <p>Methods</p> <p>In this study, the effects of 3 to 30 ΌM BA on cytotoxicity, migration, the protein expression of PARP, survivin and HIF-1α, as well as radiosensitivity under normoxic and hypoxic conditions were analyzed in the human malignant glioma cell lines U251MG and U343MG. Cytotoxicity and radiosensitivity were analyzed with clonogenic survival assays, migration was analyzed with Boyden chamber assays (or scratch assays) and protein expression was examined with Western blot analyses.</p> <p>Results</p> <p>Under normoxic conditions, a half maximal inhibitory concentration (IC<sub>50</sub>) of 23 ΌM was observed in U251MG cells and 24 ΌM was observed in U343MG cells. Under hypoxic conditions, 10 ΌM or 15 ΌM of BA showed a significantly increased cytotoxicity in U251MG cells (p = 0.004 and p = 0.01, respectively) and U343MG cells (p < 0.05 and p = 0.01, respectively). The combination of BA with radiotherapy resulted in an additive effect in the U343MG cell line under normoxic and hypoxic conditions. Weak radiation enhancement was observed in U251MG cell line after treatment with BA under normoxic conditions. Furthermore, under hypoxic conditions, the incubation with BA resulted in increased radiation enhancement. The enhancement factor, at an irradiation dose of 15 Gy after treatment with 10 or 15 ΌM BA, was 2.20 (p = 0.02) and 4.50 (p = 0.03), respectively. Incubation with BA led to decreased cell migration, cleavage of PARP and decreased expression levels of survivin in both cell lines. Additionally, BA treatment resulted in a reduction of HIF-1α protein under hypoxic conditions.</p> <p>Conclusion</p> <p>Our results suggest that BA is capable of improving the effects of tumor therapy in human malignant glioma cells, particularly under hypoxic conditions. Further investigations are necessary to characterize its potential as a radiosensitizer.</p
A potent betulinic acid analogue ascertains an antagonistic mechanism between autophagy and proteasomal degradation pathway in HT-29 cells
Betulinic acid (BA), a member of pentacyclic triterpenes has shown important biological activities like
anti-bacterial, anti-malarial, anti-inflammatory and most interestingly anticancer property. To overcome its poor
aqueous solubility and low bioavailability, structural modifications of its functional groups are made to generate
novel lead(s) having better efficacy and less toxicity than the parent compound. BA analogue, 2c was found most
potent inhibitor of colon cancer cell line, HT-29 cells with IC50 value 14.9 ÎŒM which is significantly lower than
standard drug 5-fluorouracil as well as parent compound, Betulinic acid. We have studied another mode of PCD,
autophagy which is one of the important constituent of cellular catabolic system as well as we also studied
proteasomal degradation pathway to investigate whole catabolic pathway after exploration of 2c on HT-29 cells.
Mechanism of autophagic cell death was studied using fluorescent dye like acridine orange (AO) and
monodansylcadaverin (MDC) staining by using fluorescence microscopy. Various autophagic protein expression
levels were determined by Western Blotting, qRT-PCR and Immunostaining. Confocal Laser Scanning Microscopy
(CLSM) was used to study the colocalization of various autophagic proteins. These were accompanied by formation
of autophagic vacuoles as revealed by FACS and transmission electron microscopy (TEM). Proteasomal degradation
pathway was studied by proteasome-Gloâą assay systems using luminometer.The formation of autophagic vacuoles in HT-29 cells after 2c treatment was determined by fluorescence
staining â confirming the occurrence of autophagy. In addition, 2c was found to alter expression levels of different autophagic proteins like Beclin-1, Atg 5, Atg 7, Atg 5-Atg 12, LC3B and autophagic adapter protein, p62. Furthermore we found the formation of autophagolysosome by colocalization of LAMP-1 with LC3B, LC3B with Lysosome, p62 with lysosome. Finally, as proteasomal degradation pathway downregulated after 2c treatment colocalization of ubiquitin
with lysosome and LC3B with p62 was studied to confirm that protein degradation in autophagy induced HT-29 cells
follows autolysosomal pathway. In summary, betulinic acid analogue, 2c was able to induce autophagy in HT-29 cells and as proteasomal degradation pathway downregulated after 2c treatment so protein degradation in autophagy induced HT-29 cell
Ibuprofen is deleterious for the development of first trimester human fetal ovary ex vivo
International audienceSTUDY QUESTION Does ibuprofen use during the first trimester of pregnancy interfere with the development of the human fetal ovary? SUMMARY ANSWER In human fetuses, ibuprofen exposure is deleterious for ovarian germ cells. WHAT IS KNOWN ALREADY In utero stages of ovarian development define the future reproductive capacity of a woman. In rodents, analgesics can impair the development of the fetal ovary leading to early onset of fertility failure. Ibuprofen, which is available over-the-counter, has been reported as a frequently consumed medication during pregnancy, especially during the first trimester when the ovarian germ cells undergo crucial steps of proliferation and differentiation. STUDY DESIGN, SIZE, DURATION Organotypic cultures of human ovaries obtained from 7 to 12 developmental week (DW) fetuses were exposed to ibuprofen at 1-100 ΌM for 2, 4 or 7 days. For each individual, a control culture (vehicle) was included and compared to its treated counterpart. A total of 185 individual samples were included. PARTICIPANTS/MATERIALS, SETTING, METHODS Ovarian explants were analyzed by flow cytometry, immunohistochemistry and quantitative PCR. Endpoints focused on ovarian cell number, cell death, proliferation and germ cell complement. To analyze the possible range of exposure, ibuprofen was measured in the umbilical cord blood from the women exposed or not to ibuprofen prior to termination of pregnancy. MAIN RESULTS AND THE ROLE OF CHANCE Human ovarian explants exposed to 10 and 100 ΌM ibuprofen showed reduced cell number, less proliferating cells, increased apoptosis and a dramatic loss of germ cell number, regardless of the gestational age of the fetus. Significant effects were observed after 7 days of exposure to 10 ΌM ibuprofen. At this concentration, apoptosis was observed as early as 2 days of treatment, along with a decrease in M2A-positive germ cell number. These deleterious effects of ibuprofen were not fully rescued after 5 days of drug withdrawal. LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION This study was performed in an experimental setting of human ovaries explants exposed to the drug in culture, which may not fully recapitulate the complexity of in vivo exposure and organ development. Inter-individual variability is also to be taken into account. WIDER IMPLICATIONS OF THE FINDINGS Whereas ibuprofen is currently only contra-indicated after 24 weeks of pregnancy, our results points to a deleterious effect of this drug on first trimester fetal ovaries ex vivo. These findings deserve to be considered in light of the present recommendations about ibuprofen consumption pregnancy, and reveal the urgent need for further investigations on the cellular and molecular mechanisms that underlie the effect of ibuprofen on fetal ovary development. © The Author(s) 2018. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology
- âŠ