There is now considerable direct evidence that tumor growth is angiogenesis-dependent. The most compelling evidence is based on the discovery of angiostatin, an angiogenesis inhibitor that selectively instructs endothelium to become refractory to angiogenic stimuli. Angiostatin, which specifically inhibits endothelial proliferation, induced dormancy of metastases defined by a balance of apoptosis and proliferation. We now show that systemic administration of human angiostatin potently inhibits the growth of three human and three murine primary carcinomas in mice. An almost complete inhibition of tumor growth was observed without detectable toxicity or resistance. The human carcinomas regressed to microscopic dormant foci in which tumor cell proliferation was balanced by apoptosis in the presence of blocked angiogenesis. This regression of primary tumors without toxicity has not been previously described. This is also the first demonstration of dormancy therapy, a novel anticancer strategy in which malignant tumors are regressed by prolonged blockade of angiogenesis.
The Science Teachers Learning from Lesson Analysis (STeLLA) project is a videobased analysis-ofpractice PD program aimed at improving teacher and student learning at the upper elementary level. The PD program developed and utilized two '
Organ sizes and shapes are strikingly reproducible, despite the variable growth and division of individual cells within them. To reveal which mechanisms enable this precision, we designed a screen for disrupted sepal size and shape uniformity in Arabidopsis and identified mutations in the mitochondrial i-AAA protease FtsH4. Counterintuitively, through live imaging we observed that variability of neighboring cell growth was reduced in ftsh4 sepals. We found that regular organ shape results from spatiotemporal averaging of the cellular variability in wild-type sepals, which is disrupted in the less-variable cells of ftsh4 mutants. We also found that abnormal, increased accumulation of reactive oxygen species (ROS) in ftsh4 mutants disrupts organ size consistency. In wild-type sepals, ROS accumulate in maturing cells and limit organ growth, suggesting that ROS are endogenous signals promoting termination of growth. Our results demonstrate that spatiotemporal averaging of cellular variability is required for precision in organ size.
IntroductionPseudomonas aeruginosa nosocomial pneumonia (Pa-NP) is associated with considerable morbidity, prolonged hospitalization, increased costs, and mortality.MethodsWe conducted a retrospective cohort study of adult patients with Pa-NP to determine 1) risk factors for multidrug-resistant (MDR) strains and 2) whether MDR increases the risk for hospital death. Twelve hospitals in 5 countries (United States, n = 3; France, n = 2; Germany, n = 2; Italy, n = 2; and Spain, n = 3) participated. We compared characteristics of patients who had MDR strains to those who did not and derived regression models to identify predictors of MDR and hospital mortality.ResultsOf 740 patients with Pa-NP, 226 patients (30.5%) were infected with MDR strains. In multivariable analyses, independent predictors of multidrug-resistance included decreasing age (adjusted odds ratio [AOR] 0.91, 95% confidence interval [CI] 0.96-0.98), diabetes mellitus (AOR 1.90, 95% CI 1.21-3.00) and ICU admission (AOR 1.73, 95% CI 1.06-2.81). Multidrug-resistance, heart failure, increasing age, mechanical ventilation, and bacteremia were independently associated with in-hospital mortality in the Cox Proportional Hazards Model analysis.ConclusionsAmong patients with Pa-NP the presence of infection with a MDR strain is associated with increased in-hospital mortality. Identification of patients at risk of MDR Pa-NP could facilitate appropriate empiric antibiotic decisions that in turn could lead to improved hospital survival.
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