243 research outputs found

    Cytochromes and the Succinic Acid Oxidase System of Poky Strains of Neurospora

    Get PDF
    Recent investigations in this laboratory (1) have demonstrated that in Neurospora crassa growth characteristics representing at least two stable states are possible with the same constitution of nuclear genes. If a slow growing strain, designated poky, functions in a cross to wild type as the maternal or protoperithecial parent, then all progeny from the cross exhibit the poky character. If the cross is made in the reverse, or reciprocal manner, that is, with the wild type strain functioning as a protoperithecial parent, then all progeny are normal in growth rate. During the course of the work on inheritance it was observed that mycelial pads from poky were characterized by a red color reminiscent of that of the heme pigments. Examinations of suspensions and extracts of the mold with a spectroscope yielded the information that poky mycelium contains large quantities of a substance having the absorption spectrum characteristic of cytochrome c, whereas the bands corresponding to cytochromes o and b were not visible. All three of these components were detected easily in the wild type strain. The experimental results presented here provide more precise information on the similarities and differences between these two strains with respect to the cytochrome and the succinic acid oxidase systems. Preliminary observations suggested that poky in Neurospora is analogous to petite in yeast (2) in which abnormalities in the succinic acid oxidase system have been reported, but this analogy is shown here to be only a partial one

    Refining the Pediatric Multiple Organ Dysfunction Syndrome

    Full text link
    Since its introduction into the medical literature in the 1970s, the term multiple organ dysfunction syndrome (or some variant) has been applied broadly to any patient with >1 concurrent organ dysfunction. However, the epidemiology, mechanisms, time course, and outcomes among children with multiple organ dysfunction vary substantially. We posit that the term pediatric multiple organ dysfunction syndrome (or MODS) should be reserved for patients with a systemic pathologic state resulting from a common mechanism (or mechanisms) that affects numerous organ systems simultaneously. In contrast, children in whom organ injuries are attributable to distinct mechanisms should be considered to have additive organ system dysfunctions but not the syndrome of MODS. Although such differentiation may not always be possible with current scientific knowledge, we make the case for how attempts to differentiate multiple organ dysfunction from other states of additive organ dysfunctions can help to evolve clinical and research priorities in diagnosis, monitoring, and therapy from largely organ-specific to more holistic strategies

    Scoring Systems for Organ Dysfunction and Multiple Organ Dysfunction: The PODIUM Consensus Conference

    Full text link
    CONTEXT Multiple scores exist to characterize organ dysfunction in children. OBJECTIVE To review the literature on multiple organ dysfunction (MOD) scoring systems to estimate severity of illness and to characterize the performance characteristics of currently used scoring tools and clinical assessments for organ dysfunction in critically ill children. DATA SOURCES Electronic searches of PubMed and Embase were conducted from January 1992 to January 2020. STUDY SELECTION Studies were included if they evaluated critically ill children with MOD, evaluated the performance characteristics of scoring tools for MOD, and assessed outcomes related to mortality, functional status, organ-specific outcomes, or other patient-centered outcomes. DATA EXTRACTION Data were abstracted into a standard data extraction form by a task force member. RESULTS Of 1152 unique abstracts screened, 156 full text studies were assessed including a total of 54 eligible studies. The most commonly reported scores were the Pediatric Logistic Organ Dysfunction Score (PELOD), pediatric Sequential Organ Failure Assessment score (pSOFA), Pediatric Index of Mortality (PIM), PRISM, and counts of organ dysfunction using the International Pediatric Sepsis Definition Consensus Conference. Cut-offs for specific organ dysfunction criteria, diagnostic elements included, and use of counts versus weighting varied substantially. LIMITATIONS While scores demonstrated an increase in mortality associated with the severity and number of organ dysfunctions, the performance ranged widely. CONCLUSIONS The multitude of scores on organ dysfunction to assess severity of illness indicates a need for unified and data-driven organ dysfunction criteria, derived and validated in large, heterogenous international databases of critically ill children

    Criteria for Pediatric Sepsis-A Systematic Review and Meta-Analysis by the Pediatric Sepsis Definition Taskforce

    Get PDF
    OBJECTIVE: To determine the associations of demographic, clinical, laboratory, organ dysfunction, and illness severity variable values with: 1) sepsis, severe sepsis, or septic shock in children with infection and 2) multiple organ dysfunction or death in children with sepsis, severe sepsis, or septic shock. DATA SOURCES: MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched from January 1, 2004, and November 16, 2020. STUDY SELECTION: Case-control studies, cohort studies, and randomized controlled trials in children greater than or equal to 37-week-old postconception to 18 years with suspected or confirmed infection, which included the terms "sepsis," "septicemia," or "septic shock" in the title or abstract. DATA EXTRACTION: Study characteristics, patient demographics, clinical signs or interventions, laboratory values, organ dysfunction measures, and illness severity scores were extracted from eligible articles. Random-effects meta-analysis was performed. DATA SYNTHESIS: One hundred and six studies met eligibility criteria of which 81 were included in the meta-analysis. Sixteen studies (9,629 patients) provided data for the sepsis, severe sepsis, or septic shock outcome and 71 studies (154,674 patients) for the mortality outcome. In children with infection, decreased level of consciousness and higher Pediatric Risk of Mortality scores were associated with sepsis/severe sepsis. In children with sepsis/severe sepsis/septic shock, chronic conditions, oncologic diagnosis, use of vasoactive/inotropic agents, mechanical ventilation, serum lactate, platelet count, fibrinogen, procalcitonin, multi-organ dysfunction syndrome, Pediatric Logistic Organ Dysfunction score, Pediatric Index of Mortality-3, and Pediatric Risk of Mortality score each demonstrated significant and consistent associations with mortality. Pooled mortality rates varied among high-, upper middle-, and lower middle-income countries for patients with sepsis, severe sepsis, and septic shock (p < 0.0001). CONCLUSIONS: Strong associations of several markers of organ dysfunction with the outcomes of interest among infected and septic children support their inclusion in the data validation phase of the Pediatric Sepsis Definition Taskforce

    Toll-like receptor 4 signaling in liver injury and hepatic fibrogenesis

    Get PDF
    Toll-like receptors (TLRs) are a family of transmembrane pattern recognition receptors (PRR) that play a key role in innate and adaptive immunity by recognizing structural components unique to bacteria, fungi and viruses. TLR4 is the most studied of the TLRs, and its primary exogenous ligand is lipopolysaccharide, a component of Gram-negative bacterial walls. In the absence of exogenous microbes, endogenous ligands including damage-associated molecular pattern molecules from damaged matrix and injured cells can also activate TLR4 signaling. In humans, single nucleotide polymorphisms of the TLR4 gene have an effect on its signal transduction and on associated risks of specific diseases, including cirrhosis. In liver, TLR4 is expressed by all parenchymal and non-parenchymal cell types, and contributes to tissue damage caused by a variety of etiologies. Intact TLR4 signaling was identified in hepatic stellate cells (HSCs), the major fibrogenic cell type in injured liver, and mediates key responses including an inflammatory phenotype, fibrogenesis and anti-apoptotic properties. Further clarification of the function and endogenous ligands of TLR4 signaling in HSCs and other liver cells could uncover novel mechanisms of fibrogenesis and facilitate the development of therapeutic strategies

    Heat-shock proteins in infection-mediated inflammation-induced tumorigenesis

    Get PDF
    Inflammation is a necessary albeit insufficient component of tumorigenesis in some cancers. Infectious agents directly implicated in tumorigenesis have been shown to induce inflammation. This process involves both the innate and adaptive components of the immune system which contribute to tumor angiogenesis, tumor tolerance and metastatic properties of neoplasms. Recently, heat-shock proteins have been identified as mediators of this inflammatory process and thus may provide a link between infection-mediated inflammation and subsequent cancer development. In this review, the role of heat-shock proteins in infection-induced inflammation and carcinogenesis will be discussed
    • ā€¦
    corecore