24 research outputs found

    Yersinia Has a Tropism for B and T Cell Zones of Lymph Nodes That Is Independent of the Type III Secretion System

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    Pathogenic Yersinia have a pronounced tropism for lymphatic tissues and harbor a virulence plasmid that encodes a type III secretion system, pTTSS, that transports Yops into host cells. Yops are critical virulence factors that prevent phagocytosis by macrophages and neutrophils and Yersinia mutants lacking one or more Yops are defective for survival in lymphatic tissues, liver, and gastrointestinal tract. However, here we demonstrate that Y. pseudotuberculosis (Yptb) mutants lacking the pTTSS survived as well as or better than wild-type (WT) Yptb in the mesenteric lymph nodes (MLN). Infection with pTTSS mutants caused lymphadenitis with little necrosis, whereas infection with WT Yptb provoked lymphadenitis with multiple necrotic suppurative foci. Gentamicin protection assays and microscopic examination of the MLN revealed that pTTSS mutants resided extracellularly adjacent to B and T lymphocytes in the cortex and paracortex. WT Yptb was found extracellularly adjacent to neutrophils and macrophages in necrotic areas and adjacent to B and T lymphocytes in less-inflamed areas. To determine whether lymphocytes protected pTTSS mutants from phagocytic cells, Rag1(−/−) mice were infected with pTTSS mutants or WT Yptb. pTTSS mutants but not WT, were impaired for survival in MLN of Rag1(−/−) mice, suggesting that lymphocyte-rich regions constitute a protective niche for pTTSS mutants. Finally, we show that invasin and the chromosomally encoded TTSS were not required for Yptb survival in MLN. In summary, chromosomally encoded factors are sufficient for Yptb replication in the cortex and paracortex of MLN; the pTTSS enables Yersinia to survive within phagocyte-rich areas of lymph nodes, and spread to other tissues

    Constraint-based naturalistic decision making in mission planning teams

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    Motivation – To understand the factors acting upon decision making of military planners prior to theintroduction of digital planning systems. Research approach – Participant-observation by the researchteam and direct observation of the planning process on exercises. Findings – Many different disciplinescontribute to the planning process in a co-operative and collaborative manner. Each stage in the planningprocess results in a further set of constraints being applied, each of which offer successive refinement ofthe plan. Research limitations/Implications –The research is limited to land-based military planning.Originality/Value – This research is based on field observation of military planners with tight deadlinesand a non-compliant opposing force. Take away message – ‘Military planning seems to be more aboutidentification of relevant constraints than optimization of decisions

    Two episodes of Taravana syndrome in a breath-hold diver with hyperhomocysteinemia

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    Key Clinical MessageTaravana syndrome is a rare dysbaric disease characterized by neurologic signs and symptoms. Differently from others decompression illness, it has unspecified pathophysiology and unclear predisposing factors. Our cases suggest that thrombophilic state due to hyperhomocysteinemia could increase the risk to develop Taravana syndrome

    Potential Trends in Attention Deficit Hyperactivity Disorder (ADHD) Drug Use on a College Campus: Wastewater Analysis of Amphetamine and Ritalinic Acid

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    Attention Deficit Hyperactivity Disorder (ADHD) medication use is on the rise in the United States. The most widely used ADHD medications are the amphetamine-type compounds Adderall (mixed amphetamine salts) and Ritalin (methylphenidate). According to survey data ADHD medications are used as a study drug or “Smart Drug” by students without a prescription on college campuses. Survey data of non-prescribed drug use has limitations with accurate reporting and no empirical data of usage exists in the literature. This study looks for trends in the use of these drugs on a college campus among low-stress and high stress periods. The metabolites of these two drugs, amphetamine and ritalinic acid, are quantified in campus wastewater using solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Trends show a possible increase in amphetamine levels during periods of high stress such as midterms, the last week of classes and finals week over levels from the baseline low stress weeks such as the first week of classes. Both semesters from the 2011-12 academic year were studied and the highest increase over baseline (760%) occurred during finals week of the second semester. Ritalinic acid levels gradually climbed first semester but had no obvious periodic trend second semester

    Relationship between the level of anxiety of resident doctors and patient satisfaction in De La Salle University Medical Center Out-Patient Department in January, 2015

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    This study employed the cross-sectional design. Thirty-four (34) resident doctors who were in different years of training and specialization except psychiatric and pediatrics and their 124 patients who were 20 years old and above, ambulatory, conscious and coherent, and on their first visit who needed healthcare consultation. A self-administered questionnaire was used for data collection. Data was analysed using percentage and frequency. The findings of this study revealed that most of the resident doctors (70.59% or 24 of 35) in DLSUMC OPD had normal anxiety. Majority of the patients (88.80% or 111 or 125) were satisfied to the care rendered to them. Using the statistical tools, results showed that there was a significant relationship between gender of resident doctors and level of anxiety (p=0.0306) as well as between civil status of the patients and patient satisfaction (p=0.0034)
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