1,800 research outputs found
NGC 604, the Scaled OB Association (SOBA) Prototype. I: Spatial Distribution of the Different Gas Phases and Attenuation by Dust
We have analyzed HST and ground-based data to characterize the different gas
phases and their interaction with the MYC in NGC 604, a GHR in M33. The warm
ionized gas is made out of two components: a high-excitation, high-surface
brightness H II surface located at the faces of the molecular clouds directly
exposed to the ionizing radiation of the central SOBA; and a low-excitation,
low-surface brightness halo that extends to much larger distances from the
ionizing stars. The cavities created by the winds and SN explosions are filled
with X-ray-emitting coronal gas. The nebular lines emitted by the warm gas
experience a variable attenuation as a consequence of the dust distribution,
which is patchy in the plane of the sky and with clouds interspersed among
emission-line sources in the same line of sight. The optical depth at H alpha
as measured from the ratio of the thermal radio continuum to H alpha shows a
very good correlation with the total CO (1-0) column, indicating that most of
the dust resides in the cold molecular phase. The optical depth at H alpha as
measured from the ratio of H alpha to H beta also correlates with the CO
emission but not as strongly as in the previous case. We analyze the difference
between those two measurements and we find that <=11% of the H II gas is hidden
behind large-optical-depth molecular clouds. We detect two candidate compact H
II regions embedded inside the molecular cloud; both are within short distance
of WR/Of stars and one of them is located within 16 pc of a RSG. We estimate
the age of the main stellar generation in NGC 604 to be approx. 3 Myr from the
ionization structure of the H II region. The size of the main cavity is smaller
than the one predicted by extrapolating from single-star wind-blown bubbles.Comment: 50 pages, 15 figures. To appear in the September issue of the
Astronomical Journal. Some of the figures in this version have a very low
resolution due to the absurd limitations (for 2004) imposed on file size by
astro-ph. A full-resolution version of the figures is available at
http://www.stsci.edu/~jmai
Two consecutive phase II studies of oxaliplatin (L-OHP) for treatment of patients with advanced colorectal carcinoma who were resistant to previous treatment with fluoropyrimidines
Background Oxaliplatin (L-OHP) is a platinum complex that possesses activity against human and murine cells in vitro and in vivo, including colorectal carcinoma-derived cell lines, and cells that have been selected for resistance to cisplatin. We report two consecutive phase H trials of L-OHP for treatment of patients with advanced colorectal carcinoma. Patients and methods: Fifty-eight patients were entered in study I, and 51 patients in study II. All of the patients had tumor progression when they were treated, prior to their enrolment, with a fluoropyrimidine-containing regimen. In both trials treatment consisted of L-OHP, 130 mg/m2 by i.v. infusion for two hours; the treatment was repeated every 21 days. Results Response to therapy: Study I: Fifty-five patients were assessed for response. The response rate was 11% (95% CI, 0.03-0.19). Study II: All 51 patients were assessed for response. The response rate was 10% (95% CI, 0.017-0.18). The overall response rate for the 106 evaluated patients was 10% (95% CI, 0.046-0.16). Times to disease progression in responders were 4, 4, 4.5+, 5, 5, 6, 6, 6, 6+, 9, and 13 months. The dose-limiting toxic effect was sensory peripheral neuropathy. The incidence of severe peripheral neuropathy grades was: Study I: grade 3, 23% of patients, and grade 4, 8% of patients. Study II: grade 3, 14% of patients, and grade 4, 4% of patients. Severe neuropathy had a favorable course in all of the patients who had long-term neurologic follow-up. Diarrhea and myeloid impairment were minor. Conclusion L-OHP produced modest, but definite antitumor activity in patients with advanced colorectal carcinoma who were previously resistant to chemotherapy including fluoropyrirnidines. Toxicity is within acceptable limits of tolerance at the dose and schedule of oxaliplatin used in this tria
Glycation does not modify bovine serum albumin (BSA)-induced reduction of rat aortic relaxation: The response to glycated and nonglycated BSA is lost in metabolic syndrome
The effects of nonglycated bovine serum albumin (BSA) and advanced glycosylation end products of BSA (AGE-BSA) on vascular responses of control and metabolic syndrome (MS) rats characterized by hypertriglyceridemia, hypertension, hyperinsulinemia, and insulin resistance were studied. Albumin and in vitro prepared AGE-BSA have vascular effects; however, recent studies indicate that some effects of in vitro prepared AGEs are due to the conditions in which they were generated. We produced AGEs by incubating glucose with BSA for 60 days under sterile conditions in darkness and at 37°C. To develop MS rats, male Wistar animals were given 30% sucrose in drinking water since weanling. Six month old animals were used. Blood pressure, insulin, triglycerides, and serum albumin were increased in MS rats. Contraction of aortic rings elicited with norepinephrine was stronger. There were no effects of nonglycated BSA or AGE-BSA on contractions in control or MS rats; however, both groups responded to L-NAME, an inhibitor of nitric oxide synthesis. Arterial relaxation induced using acetylcholine was smaller in MS rats. Nonglycated BSA and AGE-BSA significantly diminished relaxation in a 35% in the control group but the decrease was similar when using nonglycated BSA and AGE-BSA. This decrease was not present in the MS rats and was not due to increased RAGEs or altered biochemical characteristics of BSA. In conclusion, both BSA and AGE-BSA inhibit vascular relaxation in control artic rings. In MS rats the effect is lost possibly due to alterations in endothelial cells that are a consequence of the illness
Oncologistâs knowledge and implementation of guidelines for breakthrough cancer pain in Spain: CONOCE study
[Purpose]: Breakthrough cancer pain (BTcP) has been shown to be a prevalent and poor prognostic factor for oncologic patients, which remain under diagnosed and undertreated. In 2012, the Spanish Society of Medical Oncology (SEOM) published a clinical practice guideline (CPG) for the treatment of cancer pain which specifically addressed the management of BTcP.[Methods]: FundaciĂłn ECO designed a qualitative study using an Internet-based survey to investigate the attitudes toward, compliance with, and use of SEOM Guideline.[Results]: A total of 83 oncologists with a mean experience of 13 years responded. Overall, 82% were aware of different guidelines to manage BTcP. Notably, attitudes toward guidelines were highly positive and there was nearly unanimous agreement that CPG provided the best scientific evidence available (99%), on the minimum information to be gathered for the medical history (100%), on the need for a specific treatment for BTcP (100%), and fentanyl as the first-choice drug (99%). Interestingly, there were discrepancies between what oncologists agreed with and what they do in clinical practice. In fact, 87.6% declare full compliance with SEOM guideline, although adherence to registration of BTcP data in medical records ranged from 30.1 to 91.6% (mean 64.5%); therapeutic management compliance was higher ranging from 75.9 to 91.6%. Main barriers identified were time pressure together with vague statements and limited dissemination of the guidelines.[Conclusion]: Despite oncologistâs clinical practice is increasingly guided by GPC, it suffers from limited compliance, at least in part due to suboptimal statements. Improved dissemination and education are needed to enhance guideline implementation.This study was funded by Kyowa Kirin FarmacĂ©utica S. L.U. through FundaciĂłn ECO
Oxaliplatin as single agent in previously untreated colorectal carcinoma patients: a phase II multicentric study
Background. Oxaliplatin is a new cytotoxic agent from the diaminocyclohexane family with proven antitumor activity against colon cancer cell lines. Activity in patients with colorectal carcinoma previously treated with 5-fluorouracil has been studied in three single-agent phase II trials, showing a reproducible response rate of 10%. Here we report a phase II trial with oxaliplatin as a first-line chemotherapy for metastatic colorectal cancer.
Patients and methods: Twenty-five patients were entered in the study. All of them had metastatic disease without previous chemotherapy, and at least one lesion had to be measurable by computed tomography (CT). Therapy consisted of a two-hour infusion of oxaliplatin at a dose of 130 mg/m(2) every 21 days.
Results. The overall response rate determined by investigators was 20% (95% CI, 6.8%-40.7%). Eight patients (32%) had stable disease. The median time to disease progression in responders was six months (range four to nine). The median progression-free survival nias four months and median overall survival 14.5 months (95% CI, 10-20 months). The main toxic effects were peripheral neuropathy (92%) and laryngopharyngeal dysesthesia (75%). No severe grade 3-4 neurotoxicities (NCI-CTC) were found. Gastrointestinal and hematological toxicities were mild.
Conclusions. Oxaliplatin is an active agent in first-line chemotherapy for advanced colorectal cancer. It was well tolerated, caused no toxic deaths, had low hematotoxicity, well controlled gastrointestinal toxicity, and frequent but mild peripheral neurological symptoms. Therefore, it is of interest to associate oxaliplatin with other active compounds
Reciprocal responses in the interaction between Arabidopsis and the cell-content feeding chelicerate herbivore spider mite
Most molecular-genetic studies of plant defense responses to arthropod herbivores have focused on insects. However, plant-feeding mites are also pests of diverse plants, and mites induce different patterns of damage to plant tissues than do well-studied insects (e.g. lepidopteran larvae or aphids). The two-spotted spidermite (Tetranychus urticae) is among the most significant mite pests in agriculture, feeding on a staggering number of plant hosts. To understand the interactions between spider mite and a plant at the molecular level, we examined reciprocal genome-wide responses of mites and its host Arabidopsis (Arabidopsis thaliana). Despite differences in feeding guilds, we found that transcriptional responses of Arabidopsis to mite herbivory resembled those observed for lepidopteran herbivores. Mutant analysis of induced plant defense pathways showed functionally that only a subset of induced programs, including jasmonic acid signaling and biosynthesis of indole glucosinolates, are central to Arabidopsis's defense to mite herbivory. On the herbivore side, indole glucosinolates dramatically increased mite mortality and development times. We identified an indole glucosinolate dose-dependent increase in the number of differentially expressedmite genes belonging to pathways associated with detoxification of xenobiotics. This demonstrates that spider mite is sensitive to Arabidopsis defenses that have also been associated with the deterrence of insect herbivores that are very distantly related to chelicerates. Our findings provide molecular insights into the nature of, and response to, herbivory for a representative of a major class of arthropod herbivores
About 1% of the breast and ovarian Spanish families testing negative for BRCA1 and BRCA2 are carriers of RAD51D pathogenic variants
RAD51D mutations have been recently identified in breast (BC) and ovarian cancer (OC) families. Although an etiological role in OC appears to be present, the association of RAD51D mutations and BC risk is more unclear. We aimed to determine the prevalence of germline RAD51D mutations in Spanish BC/OC families negative for BRCA1/BRCA2 mutations. We analyzed 842 index patients: 491 from BC/OC families, 171 BC families, 51 OC families and 129 patients without family history but with early-onset BC or OC or metachronous BC and OC. Mutation detection was performed with high-resolution melting, denaturing high-performance liquid chromatography or Sanger sequencing. Three mutations were found in four families with BC and OC cases (0.82%). Two were novel: c.1A>T (p.Met1?) and c.667+2_667+23del, leading to the exon 7 skipping and one previously described: c.674C>T (p.Arg232*). All were present in BC/OC families with only one OC. The c.667+2_667+23del cosegregated in the family with one early-onset BC and two bilateral BC cases. We also identified the c.629C>T (p.Ala210Val) variant, which was predicted in silico to be potentially pathogenic. About 1% of the BC and OC Spanish families negative for BRCA1/BRCA2 are carriers of RAD51D mutations. The presence of several BC mutation carriers, albeit in the context of familial OC, suggests an increased risk for BC, which should be taken into account in the follow-up and early detection measures. RAD51D testing should be considered in clinical setting for families with BC and OC, irrespective of the number of OC cases in the family
The management of pancreatic cancer. Current expert opinion and recommendations derived from the 8th World Congress on Gastrointestinal Cancer, Barcelona, 2006
This article summarizes the expert discussion on the management of pancreatic cancer, which took place during the 8th World Congress on Gastrointestinal Cancer in June 2006 in Barcelona. A multidisciplinary approach to a patient with pancreatic cancer is essential, in order to guarantee an optimal staging, surgery, selection of the appropriate (neo-)adjuvant strategy and chemotherapeutic choice management. Moreover, optimal symptomatic management requires a dedicated team of health care professionals. Quality control of surgery and pathology is especially important in this disease with a high locoregional failure rate. There is now solid evidence in favour of chemotherapy in both the adjuvant and palliative setting, and gemcitabine combined with erlotinib, capecitabine or platinum compounds seems to be slightly more active than gemcitabine alone in advanced pancreatic cancer. There is a place for chemoradiotherapy in selected patients with locally advanced disease, while the role in the adjuvant setting remains controversial. Those involved in the care for patients with pancreatic cancer should be encouraged to participate in well-designed clinical trials, in order to increase the evidence-based knowledge and to make further progres
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