Phenotypic modulation by Legionella pneumophila upon infection of macrophages.

Since many pathogenic bacteria manifest a coordinate regulation of gene expression in response to different environmental stimuli, we examined the phenotypic response of Legionella pneumophila to infection of macrophage-like U937 cells. Intracellular L. pneumophila was radiolabeled, and cell extracts were subjected to two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. At least 35 Legionella proteins were selectively induced during infection of macrophages, and one of these proteins was not detected in organisms grown in vitro. Expression of at least 32 proteins was selectively repressed during infection of macrophages, and 9 of these proteins were undetectable in intracellularly grown organisms. Thirteen of the macrophage-induced proteins were also induced by one or more of several stress conditions in vitro, and two of these proteins were the heat shock GroEL- and GroES-like proteins. Nineteen of the macrophage-repressed proteins were also repressed by one or more of the stress conditions in vitro. Our data showed that intracellular L. pneumophila manifested a phenotypic modulation and a global stress response to the intracellular environment of the macrophage. The data suggested that multiple regulons are involved in this modulation, which may contribute to the survival of L. pneumophila within alveolar macrophages.     

Clinical frailty and its effect on the septuagenarian population after emergency laparotomy

IntroductionThe UK has an ageing population with an increased prevalence of frailty in the over 70s. Emergency laparotomy for acute intra-abdominal pathology is increasingly offered to this population. This can challenge decision making and information given to patients should not only be based on mortality outcomes but on relative expected quality of life and change to frailty syndromes.Materials and methodsThis was a single site National Emergency Laparotomy Audit (NELA)-based retrospective cohort audit for consecutive cases in the septuagenarian population assessing mortality, length of stay outcome and subjective postoperative functioning. Follow-up was conducted between one and two years postoperatively to determine this.ResultsSome 153 patients were identified throughout the single site NELA database. Median age was 79 years with a ratio of 1.7 men to women. Median rate of all-cause mortality was 35.3% at the median follow-up of 19 months. Median time from admission to death was 120 days. Of those who had died by the time of follow-up, significant preoperative indicators included clinical frailty scale (p < 0.0001), preoperative P-POSSUM (mortality). At follow-up, 35% responded to a quality of life follow-up. This revealed a decline in mid-term physical functioning, lower energy, higher fatigue and reduction in social functioning. There was also an increase in pre- and postoperative clinical frailty scale score.ConclusionIn the septuagenarian-plus population it is important to consider not only risk stratification with mortality scoring (P-POSSUM or NELA-adjusted risk), but to take into account frailty. Postoperative rehabilitation and careful recovery is paramount. Where possible, during the counselling and consent for emergency laparotomy, significant postoperative long-term deterioration in physical, emotional and social function should be considered.     

Myocardial uptake and clearance of T1-201 in healthy subjects: comparison of adenosine-induced hyperemia and exercise stress

Pharmacologic stress testing with dipyridamole is useful in patients undergoing thallium-201 myocardial perfusion scintigraphy who cannot adequately exercise. Because dipyridamole increases coronary blood flow by reducing the metabolism of adenosine, the authors compared the uptake and clearance of T1-201 following exercise stress testing (EST) and resting intravenous infusion of adenosine (AI) in crossover fashion in 20 healthy men. No perfusion defects or areas of redistribution were noted in any of the scans. Mean absolute myocardial T1-201 uptake was 1.3 times greater with AI than with EST. Mean absolute extracardiac uptake was 2.0 times greater with AI. Mean T1-201 myocardial clearance was virtually the same in all AI and EST views. During AI, 70% of the subjects experienced subjective side effects, mean arterial blood pressure decreased by 15%, and heart rate increased by 48%. The effects of adenosine on T1-201 kinetics in the myocardium are similar to those of EST. Adenosine may be useful as a pharmacologic stress agent in patients undergoing T1-201 myocardial perfusion scintigraphy.     

Growth and phenotypic characterization of Legionella species on semisolid media made with washed agar.

Legionella pneumophila (and 28 Legionella species) grew efficiently on charcoal-free, buffered yeast extract medium made with washed agar and without apparent loss of infectivity for U937 cells. Because charcoal-free, buffered yeast extract is transparent, it is a suitable base for indicator media and pigment detection. In standard media, charcoal apparently prevents agar contaminants from inhibiting Legionella growth.     

Quantitative Description of the Patient Population in a Labor and Delivery Unit

Realistic efforts should be made to quantitatively determine patient care given by labor and delivery nursing personnel. In an effort to accurately evaluate staffing requirements, the total patient population utilizing the labor and delivery room was analyzed. Of the 1,281 patients receiving treatment or evaluation, 453 were nondelivered patients (36%) who were not recorded in the average census. These nondelivered patients were analyzed according to their diagnoses. Suggestions are given on which more realistic nursing staffing can be based.     

Lymphokine abnormalities in aplastic anemia: implications for the mechanism of action of antithymocyte globulin

Anti-thymocyte globulin (ATG) provides effective therapy for many patients with aplastic anemia, and its mechanism of action has been presumed to be secondary to lymphocytotoxicity. However, our studies of lymphocyte function in aplastic anemia show marked abnormalities of lymphokine production, which ATG may modulate. In 12 of 17 patients with aplastic anemia, interleukin 2 (IL2) production was markedly elevated in vitro (P less than .01 by paired statistical analysis). Expression of the IL2 receptor, or Tac antigen, on peripheral lymphocytes assessed by flow microfluorometry was also increased above the normal range in 11 of 15 cases. Studies of ATG suggested that it might act to stimulate lymphocyte function. In vitro, ATG is a mitogen, as measured by incorporation of 3H-thymidine into blood mononuclear cells; the response of cells to ATG from patients with aplastic anemia was exaggerated in comparison with normals. Cell proliferation was accompanied by production of IL2 to levels that were, in some cases, similar to those obtained with lectin stimulation. Finally, supernatants from lymphocytes cultured in the presence of ATG were able to replace adherent cells in providing growth factors for the support of nonadherent cells in methylcellulose hematopoietic colony assays. These results provide a mechanism for an "immunostimulatory" action of ATG in effecting hematopoietic response in some patients with aplastic anemia.