319 research outputs found
1.アクラシノマイシンAのマウスL細胞に対する細胞致死効果および細胞周期へ及ぼす影響(第576回千葉医学会例会・第1回千葉大学小児外科教室例会)
PRISMA 2009 checklist. (DOC 66 kb
Synthesis of Chlorophyll-Binding Proteins in a Fully Segregated Δycf54 Strain of the Cyanobacterium Synechocystis PCC 6803
In the chlorophyll (Chl) biosynthesis pathway the formation of protochlorophyllide is catalyzed by Mg-protoporphyrin IX methyl ester (MgPME) cyclase. The Ycf54 protein was recently shown to form a complex with another component of the oxidative cyclase, Sll1214 (CycI), and partial inactivation of the ycf54 gene leads to Chl deficiency in cyanobacteria and plants. The exact function of the Ycf54 is not known, however, and further progress depends on construction and characterization of a mutant cyanobacterial strain with a fully inactivated ycf54 gene. Here, we report the complete deletion of the ycf54 gene in the cyanobacterium Synechocystis 6803; the resulting Δycf54 strain accumulates huge concentrations of the cyclase substrate MgPME together with another pigment, which we identified using nuclear magnetic resonance as 3-formyl MgPME. The detection of a small amount (~13%) of Chl in the Δycf54 mutant provides clear evidence that the Ycf54 protein is important, but not essential, for activity of the oxidative cyclase. The greatly reduced formation of protochlorophyllide in the Δycf54 strain provided an opportunity to use 35S protein labeling combined with 2D electrophoresis to examine the synthesis of all known Chl-binding protein complexes under drastically restricted de novo Chl biosynthesis. We show that although the Δycf54 strain synthesizes very limited amounts of photosystem I and the CP47 and CP43 subunits of photosystem II (PSII), the synthesis of PSII D1 and D2 subunits and their assembly into the reaction centre (RCII) assembly intermediate were not affected. Furthermore, the levels of other Chl complexes such as cytochrome b6f and the HliD– Chl synthase remained comparable to wild-type. These data demonstrate that the requirement for de novo Chl molecules differs completely for each Chl-binding protein. Chl traffic and recycling in the cyanobacterial cell as well as the function of Ycf54 are discussed
Increased body mass index and adjusted mortality in ICU patients with sepsis or septic shock: a systematic review and meta-analysis
BACKGROUND: At least 25 % of adults admitted to intensive care units (ICU) in the United States have an overweight, obese or morbidly obese body mass index (BMI). The effect of BMI on adjusted mortality in adults requiring ICU treatment for sepsis is unclear. We performed a systematic review of adjusted all-cause mortality for underweight, overweight, obese and morbidly obese BMIs relative to normal BMI for adults admitted to the ICU with sepsis, severe sepsis, and septic shock. METHOD: PubMed, the Cochrane Library, and EMBASE electronic databases were searched through November 18, 2015, without language restrictions. We included studies that reported multivariate regression analyses for all-cause mortality using standard BMI categories for adults admitted to the ICU for sepsis, severe sepsis, and septic shock. Articles were selected by consensus among multiple reviewers. Electronic database searches yielded 10,312 articles, of which six were eligible. Data were extracted by one reviewer and then reviewed by three independent reviewers. For the meta-analyses performed, the adjusted odds ratios (aOR) of mortality were combined using a random-effects model. Risk of bias was assessed using the Newcastle-Ottawa quality assessment scale for cohort studies. RESULTS: Four retrospective (n = 6609 patients) and two prospective (n = 556) studies met inclusion criteria. Compared to normal BMI, across five studies each, overweight or obese BMIs reduced the adjusted odds ratio (95 % CI) of mortality [aOR] [0.83 (0.75, 0.91) p < 0.001 and 0.82 (0.67, 0.99) p = 0.04, respectively] with low or moderate heterogeneity (I(2) = 15.7 %, p = 0.31 and I(2) = 53.0 %, p = 0.07, respectively). Across three studies each, morbidly obese BMI and underweight BMI did not alter aOR [0.90 (0.59, 1.39), p = 0.64; I(2) = 43.3 %, p = 0.17; and 1.24 (0.79, 1.95), p = 0.35; I(2) = 15.6 %, p = 0.31 respectively]. Only one study clearly defined how and when height and weight measurements were calculated. Site of underlying infection and illness severity may have favored overweight and obese BMIs. CONCLUSIONS: This is the first meta-analysis to show that overweight or obese BMIs reduce adjusted mortality in adults admitted to the ICU with sepsis, severe sepsis, or septic shock. More rigorous studies that address these limitations are needed to clarify the impact of BMI on sepsis ICU outcomes. TRIAL REGISTRATION: PROSPERO International prospective register of systematic reviews 10.15124/CRD42014010556. Registered on July 11, 2014. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13054-016-1360-z) contains supplementary material, which is available to authorized users
Previous immune checkpoint inhibitor therapy is associated with decreased COVID-19-related hospitalizations and complications in patients with cancer: Results of a propensity-matched analysis of the OnCovid registry.
Objectives: To date, studies have not provided definitive answers regarding whether previous immune checkpoint inhibitor (ICI) treatment alters outcomes for cancer patients with COVID-19. Methods: The OnCovid registry (NCT04393974) was searched from February 27, 2020, to January 31, 2022, for patients who received systemic anti-cancer therapy in the 4 weeks before laboratory-confirmed COVID-19 diagnosis. Propensity-score matching using country, vaccination status, primary tumor type, sex, age, comorbidity burden, tumor stage, and remission status investigated differences in predefined clinical outcomes comparing those who had or had not received ICIs. Results: Of 3523 patients screened, 137 ICI-only and 1378 non-ICI met inclusion criteria. Before matching, ICI patients were older, male, enrolled at centers in Italy, and had histories of smoking, thoracic cancers, advanced cancer stages, and active malignancies (P ≤0.02). After matching, there were 120 ICI and 322 non-ICI patients. ICI patients had no differences (odds ratio: 95% CI) in presenting COVID-19 symptoms (0.69: 0.37-1.28), receipt of COVID-specific therapy (0.88: 0.54-1.41), 14-day (0.95: 0.56-1.61), or 28-day (0.79: 0.48-1.29) mortalities. However, ICI patients required less COVID-19-related hospitalization (0.37: 0.21-0.67) and oxygen therapy (0.51: 0.31-0.83) and developed fewer complications (0.57: 0.36-0.92). Conclusion: In this propensity-score matched analysis, previous ICI therapy did not worsen and potentially improved COVID-19 outcomes in patients with cancer
The Heart Is an Early Target of Anthrax Lethal Toxin in Mice: A Protective Role for Neuronal Nitric Oxide Synthase (nNOS)
Anthrax lethal toxin (LT) induces vascular insufficiency in experimental animals through unknown mechanisms. In this study, we show that neuronal nitric oxide synthase (nNOS) deficiency in mice causes strikingly increased sensitivity to LT, while deficiencies in the two other NOS enzymes (iNOS and eNOS) have no effect on LT-mediated mortality. The increased sensitivity of nNOS−/− mice was independent of macrophage sensitivity to toxin, or cytokine responses, and could be replicated in nNOS-sufficient wild-type (WT) mice through pharmacological inhibition of the enzyme with 7-nitroindazole. Histopathological analyses showed that LT induced architectural changes in heart morphology of nNOS−/− mice, with rapid appearance of novel inter-fiber spaces but no associated apoptosis of cardiomyocytes. LT-treated WT mice had no histopathology observed at the light microscopy level. Electron microscopic analyses of LT-treated mice, however, revealed striking pathological changes in the hearts of both nNOS−/− and WT mice, varying only in severity and timing. Endothelial/capillary necrosis and degeneration, inter-myocyte edema, myofilament and mitochondrial degeneration, and altered sarcoplasmic reticulum cisternae were observed in both LT-treated WT and nNOS−/− mice. Furthermore, multiple biomarkers of cardiac injury (myoglobin, cardiac troponin-I, and heart fatty acid binding protein) were elevated in LT-treated mice very rapidly (by 6 h after LT injection) and reached concentrations rarely reported in mice. Cardiac protective nitrite therapy and allopurinol therapy did not have beneficial effects in LT-treated mice. Surprisingly, the potent nitric oxide scavenger, carboxy-PTIO, showed some protective effect against LT. Echocardiography on LT-treated mice indicated an average reduction in ejection fraction following LT treatment in both nNOS−/− and WT mice, indicative of decreased contractile function in the heart. We report the heart as an early target of LT in mice and discuss a protective role for nNOS against LT-mediated cardiac damage
Concerted Complex Assembly and GTPase Activation in the Chloroplast Signal Recognition Particle
Surviving Sepsis Campaign: international guidelines for management of severe sepsis and septic shock, 2012
OBJECTIVE: To provide an update to the "Surviving Sepsis Campaign Guidelines for Management of Severe Sepsis and Septic Shock," last published in 2008.
DESIGN: A consensus committee of 68 international experts representing 30 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict of interest policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independent of any industry funding. A stand-alone meeting was held for all subgroup heads, co- and vice-chairs, and selected individuals. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development.
METHODS: The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence from high (A) to very low (D) and to determine the strength of recommendations as strong (1) or weak (2). The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasized. Recommendations were classified into three groups: (1) those directly targeting severe sepsis; (2) those targeting general care of the critically ill patient and considered high priority in severe sepsis; and (3) pediatric considerations.
RESULTS: Key recommendations and suggestions, listed by category, include: early quantitative resuscitation of the septic patient during the first 6 h after recognition (1C); blood cultures before antibiotic therapy (1C); imaging studies performed promptly to confirm a potential source of infection (UG); administration of broad-spectrum antimicrobials therapy within 1 h of the recognition of septic shock (1B) and severe sepsis without septic shock (1C) as the goal of therapy; reassessment of antimicrobial therapy daily for de-escalation, when appropriate (1B); infection source control with attention to the balance of risks and benefits of the chosen method within 12 h of diagnosis (1C); initial fluid resuscitation with crystalloid (1B) and consideration of the addition of albumin in patients who continue to require substantial amounts of crystalloid to maintain adequate mean arterial pressure (2C) and the avoidance of hetastarch formulations (1B); initial fluid challenge in patients with sepsis-induced tissue hypoperfusion and suspicion of hypovolemia to achieve a minimum of 30 mL/kg of crystalloids (more rapid administration and greater amounts of fluid may be needed in some patients (1C); fluid challenge technique continued as long as hemodynamic improvement is based on either dynamic or static variables (UG); norepinephrine as the first-choice vasopressor to maintain mean arterial pressure ≥65 mmHg (1B); epinephrine when an additional agent is needed to maintain adequate blood pressure (2B); vasopressin (0.03 U/min) can be added to norepinephrine to either raise mean arterial pressure to target or to decrease norepinephrine dose but should not be used as the initial vasopressor (UG); dopamine is not recommended except in highly selected circumstances (2C); dobutamine infusion administered or added to vasopressor in the presence of (a) myocardial dysfunction as suggested by elevated cardiac filling pressures and low cardiac output, or (b) ongoing signs of hypoperfusion despite achieving adequate intravascular volume and adequate mean arterial pressure (1C); avoiding use of intravenous hydrocortisone in adult septic shock patients if adequate fluid resuscitation and vasopressor therapy are able to restore hemodynamic stability (2C); hemoglobin target of 7-9 g/dL in the absence of tissue hypoperfusion, ischemic coronary artery disease, or acute hemorrhage (1B); low tidal volume (1A) and limitation of inspiratory plateau pressure (1B) for acute respiratory distress syndrome (ARDS); application of at least a minimal amount of positive end-expiratory pressure (PEEP) in ARDS (1B); higher rather than lower level of PEEP for patients with sepsis-induced moderate or severe ARDS (2C); recruitment maneuvers in sepsis patients with severe refractory hypoxemia due to ARDS (2C); prone positioning in sepsis-induced ARDS patients with a PaO (2)/FiO (2) ratio of ≤100 mm Hg in facilities that have experience with such practices (2C); head-of-bed elevation in mechanically ventilated patients unless contraindicated (1B); a conservative fluid strategy for patients with established ARDS who do not have evidence of tissue hypoperfusion (1C); protocols for weaning and sedation (1A); minimizing use of either intermittent bolus sedation or continuous infusion sedation targeting specific titration endpoints (1B); avoidance of neuromuscular blockers if possible in the septic patient without ARDS (1C); a short course of neuromuscular blocker (no longer than 48 h) for patients with early ARDS and a PaO (2)/FI O (2) 180 mg/dL, targeting an upper blood glucose ≤180 mg/dL (1A); equivalency of continuous veno-venous hemofiltration or intermittent hemodialysis (2B); prophylaxis for deep vein thrombosis (1B); use of stress ulcer prophylaxis to prevent upper gastrointestinal bleeding in patients with bleeding risk factors (1B); oral or enteral (if necessary) feedings, as tolerated, rather than either complete fasting or provision of only intravenous glucose within the first 48 h after a diagnosis of severe sepsis/septic shock (2C); and addressing goals of care, including treatment plans and end-of-life planning (as appropriate) (1B), as early as feasible, but within 72 h of intensive care unit admission (2C). Recommendations specific to pediatric severe sepsis include: therapy with face mask oxygen, high flow nasal cannula oxygen, or nasopharyngeal continuous PEEP in the presence of respiratory distress and hypoxemia (2C), use of physical examination therapeutic endpoints such as capillary refill (2C); for septic shock associated with hypovolemia, the use of crystalloids or albumin to deliver a bolus of 20 mL/kg of crystalloids (or albumin equivalent) over 5-10 min (2C); more common use of inotropes and vasodilators for low cardiac output septic shock associated with elevated systemic vascular resistance (2C); and use of hydrocortisone only in children with suspected or proven "absolute"' adrenal insufficiency (2C).
CONCLUSIONS: Strong agreement existed among a large cohort of international experts regarding many level 1 recommendations for the best care of patients with severe sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for this important group of critically ill patients
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