215 research outputs found
Hematemesis, a Distended Abdomen, and Pulseless Electrical Activity – An Unusual Presentation of Boerhaave’s Syndrome
Case Presentation
An 82-year-old male with a past medical history significant for coronary artery disease with three stents placed over the last 15 months, diastolic heart failure with preserved EF, atrial fibrillation on warfarin, colon cancer status-post sigmoid resection and prostate cancer status-post prostatectomy who presented with three episodes of melena, hematemesis, and weakness. The patient was in his usual state of health prior to these symptoms. He had no history of gastrointestinal (GI) bleeding or other GI pathology and was a non-drinker and non-smoker. He denied frequent use of non-steroidal anti-inflammatory medications
We came, we saw, we cannulated?
Introduction: Despite advances in management of patients with severe acute respiratory distress syndrome (ARDS), mortality due to ARDS still remains high. In patients with refractory gas-exchange abnormalities, extracorporeal membrane oxygenation (ECMO) is considered as salvage therapy that aims to decrease ventilator induced lung injury and provide lung rest. injury and provide lung rest.
Methods: We conducted a retrospective study of patients diagnosed with ARDS from October 2010 to September 2012. The aim of the study was to describe the population of patients placed on ECMO for ARDS in our institution. All patients placed on ARDSnet protocol were identified in the electronic patient record. Demographic, laboratory and ventilator data was extracted. Specifically mode of ventilation, use of rescue modalities (which included inhaled epoprostenol, skeletal muscle paralytics and/or use of airway pressure release ventilation (APRV)), Murray score, Oxygenation Index (OI), Alveolar-arterial gradient (A-a) and PaO2/FiO2 ratio (P/F) were tabulated. Survival to hospital discharge was recorded.
Results: We identified a total of 149 patients. Of these 87 were managed per ARDSnet protocol, 48 received rescue modalities, and 14 patients were placed on ECMO in addition to rescue therapy after a mean interval of 72 hours. Six of 14 patients were placed on veno-arterial ECMO and the rest on veno-venous ECMO.
Table 1 shows the baseline characteristics of these patients.
Table 2 depicts the etiology of ARDS among our patient population.
Mortality was higher in the ARDS group treated with rescue modalities (other than ECMO) compared to the group placed on ECMO as additional rescue therapy (77% vs. 50%; p = 0.3243). The ECMO group had a survival advantage despite higher A-a gradient, PaO2/Fio2 ratio, Oxygenation Index and Murray Score in the ECMO group (Table 1).
Conclusion: Patients with ARDS placed on ECMO had an absolute reduction in mortality of 27% when compared to other rescue modalities. However this did not reach statistical significance due to the small sample size. We believe that ECMO is an important rescue modality in the right clinical setting. Treating physicians should consider ECMO as a treatment modality for severe ARDS patients
How does cognitive load influence speech perception? : An encoding hypothesis
Two experiments investigated the conditions under which cognitive load exerts an effect on speech perception. These experiments extend earlier research by using a different speech perception task (four-interval oddity task) and by implementing cognitive load through a task often thought to be modular, namely, face processing. In the cognitive-load conditions, participants were required to remember two faces presented before the speech stimuli. In Experiment 1, performance in the speech-perception task under cognitive load was not impaired in comparison to a no-load baseline condition. In Experiment 2, we modified the load condition minimally such that it required encoding of the two faces simultaneously with the speech stimuli. As a reference condition, we also used a visual search task that in earlier experiments had led to poorer speech perception. Both concurrent tasks led to decrements in the speech task. The results suggest that speech perception is affected even by loads thought to be processed modularly, and that, critically, encoding in working memory might be the locus of interference
Effective Rheology of Bubbles Moving in a Capillary Tube
We calculate the average volumetric flux versus pressure drop of bubbles
moving in a single capillary tube with varying diameter, finding a square-root
relation from mapping the flow equations onto that of a driven overdamped
pendulum. The calculation is based on a derivation of the equation of motion of
a bubble train from considering the capillary forces and the entropy production
associated with the viscous flow. We also calculate the configurational
probability of the positions of the bubbles.Comment: 4 pages, 1 figur
Ferritin immobilization on patterned poly(2-hydroxyethyl methacrylate) brushes on silicon surfaces from colloid system
In this paper, we describe a graft polymerization/solvent immersion method for generating poly(2-hydroxyethyl methacrylate) (PHEMA) brushes in various patterns. We used a novel fabrication process, involving very-large-scale integration and oxygen plasma treatment, to generate well-defined patterns of polymerized PHEMA on patterned Si(100) surfaces. We observed brush- and mushroom-like regions for the PHEMA brushes, with various pattern resolutions, after immersing wafers presenting lines of these polymers in MeOH and n-hexane, respectively. The interaction between PHEMA and ferritin protein sheaths in MeOH and n-hexane (good and poor solvent for PHEMA, respectively) was used to capture and release ferritins from fluidic system. The “tentacles” behaver for PHEMA brushes was found through various solvents in fluidic system. Using high-resolution scanning electron microscopy, we observed patterned ferritin Fe cores on the Si surface after pyrolysis of the patterned PHEMA brushes and ferritin protein sheaths, which verify the “tentacles” behaver for PHEMA brushes
Targeting of T/Tn Antigens with a Plant Lectin to Kill Human Leukemia Cells by Photochemotherapy
Photochemotherapy is used both for solid tumors and in extracorporeal treatment of various hematologic disorders. Nevertheless, its development in oncology remains limited, because of the low selectivity of photosensitizers (PS) towards human tumor cells. To enhance PS efficiency, we recently covalently linked a porphyrin (TrMPyP) to a plant lectin (Morniga G), known to recognize with high affinity tumor-associated T and Tn antigens. The conjugation allowed a quick uptake of PS by Tn-positive Jurkat leukemia cells and efficient PS-induced phototoxicity. The present study was performed: (i) to evaluate the targeting potential of the conjugate towards tumor and normal cells and its phototoxicity on various leukemia cells, (ii) to investigate the mechanism of conjugate-mediated cell death. The conjugate: (i) strongly increased (×1000) the PS phototoxicity towards leukemic Jurkat T cells through an O-glycan-dependent process; (ii) specifically purged tumor cells from a 1∶1 mixture of Jurkat leukemia (Tn-positive) and healthy (Tn-negative) lymphocytes, preserving the activation potential of healthy lymphocytes; (iii) was effective against various leukemic cell lines with distinct phenotypes, as well as fresh human primary acute and chronic lymphoid leukemia cells; (iv) induced mostly a caspase-independent cell death, which might be an advantage as tumor cells often resist caspase-dependent cell death. Altogether, the present observations suggest that conjugation with plant lectins can allow targeting of photosensitizers towards aberrant glycosylation of tumor cells, e.g. to purge leukemia cells from blood and to preserve the normal leukocytes in extracorporeal photochemotherapy
Oncogenic KRAS sensitises colorectal tumour cells to chemotherapy by p53-dependent induction of Noxa
BACKGROUND: Oxaliplatin and 5-fluorouracil (5-FU) currently form the backbone of conservative treatment in patients with metastatic colorectal cancer. Tumour responses to these agents are highly variable, but the underlying mechanisms are poorly understood. Our previous results have indicated that oncogenic KRAS in colorectal tumour cells sensitises these cells to chemotherapy. METHODS: FACS analysis was used to determine cell-cycle distribution and the percentage of apoptotic and mitotic cells. A multiplexed RT-PCR assay was used to identify KRAS-controlled apoptosis regulators after exposure to 5-FU or oxaliplatin. Lentiviral expression of short-hairpin RNAs was used to suppress p53 or Noxa. RESULTS: Oncogenic KRAS sensitised colorectal tumour cells to oxaliplatin and 5-FU in a p53-dependent manner and promoted p53 phosphorylation at Ser37 and Ser392, without affecting p53 stabilisation, p21 induction, or cell-cycle arrest. Chemotherapy-induced expression of the p53 target gene Noxa was selectively enhanced by oncogenic KRAS. Suppression of Noxa did not affect p21 induction or cell-cycle arrest, but reduced KRAS/p53-dependent apoptosis after exposure to chemotherapy in vitro and in tumour xenografts. Noxa suppression did not affect tumour growth per se, but strongly reduced the response of these tumours to chemotherapy. CONCLUSION: Oncogenic KRAS determines the cellular response to p53 activation by oxaliplatin or 5-FU, by facilitating apoptosis induction through Noxa. British Journal of Cancer (2010) 102, 1254-1264. doi: 10.1038/sj.bjc.6605633 www.bjcancer.com Published online 30 March 2010 (C) 2010 Cancer Research U
Impact of maritime traffic on polycyclic aromatic hydrocarbons, metals and particulate matter in Venice air
Harbours are important hubs for economic growth in both tourism and commercial activities. They are also an environmental burden being a source of atmospheric pollution often localized near cities and industrial complexes. The aim of this study is to quantify the relative contribution of maritime traffic and harbour activities to atmospheric pollutant concentration in the Venice lagoon. The impact of ship traffic was quantified on various pollutants that are not directly included in the current European legislation for shipping emission reduction: (i) gaseous and particulate PAHs; (ii) metals in PM10; and (iii) PM10 and PM2.5. All contributions were correlated with the tonnage of ships during the sampling periods and results were used to evaluate the impact of the European Directive 2005/33/EC on air quality in Venice comparing measurements taken before and after the application of the Directive (year 2010). The outcomes suggest that legislation on ship traffic, which focused on the issue of the emissions of sulphur oxides, could be an efficient method also to reduce the impact of shipping on primary particulate matter concentration; on the other hand, we did not observe a significant reduction in the contribution of ship traffic and harbour activities to particulate PAHs and metals
Critical Loss of the Balance between Th17 and T Regulatory Cell Populations in Pathogenic SIV Infection
Chronic immune activation and progression to AIDS are observed after SIV infection in macaques but not in natural host primate species. To better understand this dichotomy, we compared acute pathogenic SIV infection in pigtailed macaques (PTs) to non-pathogenic infection in African green monkeys (AGMs). SIVagm-infected PTs, but not SIVagm-infected AGMs, rapidly developed systemic immune activation, marked and selective depletion of IL-17-secreting (Th17) cells, and loss of the balance between Th17 and T regulatory (Treg) cells in blood, lymphoid organs, and mucosal tissue. The loss of Th17 cells was found to be predictive of systemic and sustained T cell activation. Collectively, these data indicate that loss of the Th17 to Treg balance is related to SIV disease progression
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