Phenotypic switching in Pseudomonas brassicacearum involves GacS- and GacA-dependent Rsm small RNAs.

The plant-beneficial bacterium Pseudomonas brassicacearum forms phenotypic variants in vitro as well as in planta during root colonization under natural conditions. Transcriptome analysis of typical phenotypic variants using microarrays containing coding as well as noncoding DNA fragments showed differential expression of several genes relevant to secondary metabolism and of the small RNA (sRNA) genes rsmX, rsmY, and rsmZ. Naturally occurring mutations in the gacS-gacA system accounted for phenotypic switching, which was characterized by downregulation of antifungal secondary metabolites (2,4-diacetylphloroglucinol and cyanide), indoleacetate, exoenzymes (lipase and protease), and three different N-acyl-homoserine lactone molecules. Moreover, in addition to abrogating these biocontrol traits, gacS and gacA mutations resulted in reduced expression of the type VI secretion machinery, alginate biosynthesis, and biofilm formation. In a gacA mutant, the expression of rsmX was completely abolished, unlike that of rsmY and rsmZ. Overexpression of any of the three sRNAs in the gacA mutant overruled the pleiotropic changes and restored the wild-type phenotypes, suggesting functional redundancy of these sRNAs. In conclusion, our data show that phenotypic switching in P. brassicacearum results from mutations in the gacS-gacA system.

Two GacA-dependent small RNAs modulate the quorum-sensing response in Pseudomonas aeruginosa.

In Pseudomonas aeruginosa, the GacS/GacA two-component system positively controls the quorum-sensing machinery and the expression of extracellular products via two small regulatory RNAs, RsmY and RsmZ. An rsmY rsmZ double mutant and a gacA mutant were similarly impaired in the synthesis of the quorum-sensing signal N-butanoyl-homoserine lactone, the disulfide bond-forming enzyme DsbA, and the exoproducts hydrogen cyanide, pyocyanin, elastase, chitinase (ChiC), and chitin-binding protein (CbpD). Both mutants showed increased swarming ability, azurin release, and early biofilm development.

Adiposity in children born small for gestational age.

Epidemiological studies indicate that children born small for gestational age (SGA) have an increased risk of metabolic and cardiovascular disorders as adults. This suggests that foetal undernutrition leads to permanent metabolic alterations, which predispose to metabolic abnormalities upon exposure to environmental factors such as low physical activity and/or high-energy intake in later life (thrifty phenotype hypothesis). However, this relationship is not restricted to foetal undernutrition or intrauterine growth retardation, but is also found for children born premature, or for high birth weight children. Furthermore, early post-natal nutrition, and more specifically catch-up growth, appear to modulate cardiovascular risk as well. Intrauterine growth retardation can be induced in animal models by energy/protein restriction, or ligation of uterine arteries. In such models, altered glucose homeostasis, including low beta-cell mass, low insulin secretion and insulin resistance is observed after a few weeks of age. In humans, several studies have confirmed that children born SGA have insulin resistance as adolescents and young adults. Alterations of glucose homeostasis and increased lipid oxidation can indeed be observed already in non-diabetic children born SGA at early pubertal stages. These children also have alterations of stature and changes in body composition (increased fat mass), which may contribute to the pathogenesis of insulin resistance. Permanent metabolic changes induced by foetal/early neonatal nutrition (metabolic inprinting) may involve modulation of gene expression through DNA methylation, or alterations of organ structure. It is also possible that events occurring during foetal/neonatal development lead to long-lasting alterations of the hypothalamo-pituitary-adrenal axis or the hypothalamo-pituitary-insulin-like growth factor-1 axis.

Small dense lipoproteins, apolipoprotein B, and risk of coronary events in HIV-infected patients on antiretroviral therapy: the Swiss HIV Cohort Study.

OBJECTIVES: HIV infection and exposure to certain antiretroviral drugs is associated with dyslipidemia and increased risk for coronary events. Whether this risk is mediated by highly atherogenic lipoproteins is unclear. We investigated the association of highly atherogenic small dense low-density lipoproteins (LDLs) and apolipoprotein B and coronary events in HIV-infected individuals receiving antiretroviral therapy. METHODS: We conducted a case-control study nested into the Swiss HIV Cohort Study to investigate the association of small dense LDL and apolipoprotein B and coronary events in 98 antiretroviral drug-treated patients with a first coronary event (19 fatal and 79 nonfatal coronary events with 53 definite and 15 possible myocardial infarctions, 11 angioplasties or bypasses) and 393 treated controls matched for age, gender, and smoking status. Lipids were measured by ultracentrifugation. RESULTS: In models including cholesterol, triglycerides, high-density lipoprotein cholesterol, blood pressure, central obesity, diabetes, and family history, there was an independent association between small dense LDL and coronary events [odds ratio (OR) for 1 mg/dL increase: 1.06, 95% confidence interval (CI): 1.00 to 1.11] and apolipoprotein B (OR for 10 mg/dL increase: 1.16, 95% CI: 1.02 to 1.32). When adding HIV and antiretroviral therapy-related variables, ORs were 1.04 (95% CI: 0.99 to 1.10) for small dense LDL and 1.13 (95% CI: 0.99 to 1.30) for apolipoprotein B. In both models, blood pressure and HIV viral load was independently associated with the odds for coronary events. CONCLUSIONS: HIV-infected patients receiving antiretroviral therapy with elevate small dense LDL and apolipoprotein B are at increased risk for coronary events as are patients without sustained HIV suppression.

Production of Pseudomonas aeruginosa Intercellular Small Signaling Molecules in Human Burn Wounds

Pseudomonas aeruginosa has developed a complex cell-to-cell communication system that relies on low-molecular weight excreted molecules to control the production of its virulence factors. We previously characterized the transcriptional regulator MvfR, that controls a major network of acute virulence functions in P. aeruginosa through the control of its ligands, the 4-hydroxy-2-alkylquinolines (HAQs)-4-hydroxy-2-heptylquinoline (HHQ) and 3,4-dihydroxy-2-heptylquinoline (PQS). Though HHQ and PQS are produced in infected animals, their ratios differ from those in bacterial cultures. Because these molecules are critical for the potency of activation of acute virulence functions, here we investigated whether they are also produced during human P. aeruginosa acute wound infection and whether their ratio is similar to that observed in P. aeruginosa-infected mice. We found that a clinically relevant P. aeruginosa isolate produced detectable levels of HAQs with ratios of HHQ and PQS that were similar to those produced in burned and infected animals, and not resembling ratios in bacterial cultures. These molecules could be isolated from wound tissue as well as from drainage liquid. These results demonstrate for the first time that HAQs can be isolated and quantified from acute human wound infection sites and validate the relevance of previous studies conducted in mammalian models of infection.

Strategic behaviours in healthcare : evidence from primary care and pharmaceutical markets

We analyse the strategic behaviours of agents in a market through the appropriate¬ness of their skills to the market. If agents' skills are well adapted to market and they can reach their target, they will not need to adopt strategic behaviours. The agents will behave as selfish individuals. However, if their skills are not well adapted and they cannot attain their target alone, they will adopt strategic behaviours to reach their objectives. These behaviours will have a different impact on the utilities of other agents, depending on the skills and the objectives of the agent. If these agents need other agents to reach their objectives, they will behave as altruistic individuals who internalise the utilities of other agents in reaching their objectives and will adopt cooperative behaviours. However, if these agents fear that other agents could prevent them from reaching their target because they can foresee that the skills of other agents are better adapted than their own skills, the agents will then behave as predator individuals and will adopt destructive behaviours to attain their objective. It is in the interests of these agents to manipulate information to increase disorder and dissimulate their lack of skills. They will reproduce the strategies of animals that modify their appearance to escape predators or simulate being bait to attract their prey. These agents will seek to induce chaos into the behaviours of other agents to amplify the impact of their strategies. The appropriateness of skills to the market allows an understanding of the emer-gence of networks and associated strategies. The members of a networks are inputs who are excluded when their costs are higher than their benefits. A network simul-taneously allows cooperation and selfish, predatory behaviours among its members. A network may adopt informational strategies when seeking to become the leader in a market or when it cannot survive. The creation of networks and the manipulation of information are two overlapping evolutionary strategies, with the first strategy favouring the second. In our model, an agent does not behave like a firm that aims only to maximise the profits of the firm but rather as a member of a network who adopts strategic behaviours as a function of the interests of this network. If his skills are well adapted to the market and he can innovate, he will not invest in erroneous input; in contrast, if his skills are not adapted, the agent will invest in the erroneous input of information into the market in order to survive. Therefore, when any informational asymmetries between the agents and their principals characterise the market, the price cannot be the main element that allows equilibrium to be reached in the market; instead, the appropriateness of skills to the market enables equilibrium. We will now apply these hypotheses to explain the strategic behaviours of physicians and pharmaceutical companies.

Brain-derived neurotrophic factor-like immunoreactivity is localized mainly in small sensory neurons of rat dorsal root ganglia.

Brain-derived neurotrophic factor (BDNF) is a protein capable of supporting the survival and fiber outgrowth of peripheral sensory neurons. It has been argued that histological detection of BDNF has proven difficult because of its low molecular weight and relatively low expression. In the present study we report that rapid removal of dorsal root ganglia (DRG) from the rat, followed by rapid freezing and appropriate fixation with cold acetone, preserves BDNF in situ without altering protein antigenicity. Under these conditions, specific BDNF-like immunoreactivity was detected in DRG both in vivo and in vitro. During DRG development in vivo, BDNF-like immunoreactivity (BDNF-LI) was observed only in a subset of sensory neurons. BDNF-LI was confined to small neurons, after neurons became morphologically distinct on the basis of size. BDNF-L immunoprecipitate was detected only in neuronal cells, and not in satellite or Schwann cells. While in vivo BDNF localization was restricted to small neurons, practically all neurons in DRG cell culture displayed BDNF-LI. Small or large primary afferent neurons exhibited a faint but clear BDNF-LI during the whole life span of cultures. Again, non-neuronal cells were devoid of BDNF-LI. In conclusion, in DRG in vivo, specific BDNF-LI was confined to small B sensory neurons. In contrast, all DRG sensory neurons displayed BDNF-LI in vitro. The finding that BDNF expressed in all DRG neurons in vitro but not in vivo suggests that BDNF expression may be modulated by environmental factors.

Consistency and population sensitivity properties in marriage and Rrommate markets

We consider one-to-one matching markets in which agents can either be matched as pairs or remain single. In these so-called roommate markets agents are consumers and resources at the same time. Klaus (Games Econ Behav 72:172-186, 2011) introduced two new "population sensitivity" properties that capture the effect newcomers have on incumbent agents: competition sensitivity and resource sensitivity. On various roommate market domains (marriage markets, no-odd-rings roommate markets, solvable roommate markets),we characterize the core using either of the population sensitivity properties in addition to weak unanimity and consistency. On the domain of all roommate markets, we obtain two associated impossibility results.

Small Cities, Neoliberal Governance and Sustainable Development in the Global South : A Conceptual Framework and Research Agenda

Development and environmental issues of small cities in developing countries have largely been overlooked although these settlements are of global demographic importance and often face a "triple challenge"; that is, they have limited financial and human resources to address growing environmental problems that are related to both development (e.g., pollution) and under-development (e.g., inadequate water supply). Neoliberal policy has arguably aggravated this challenge as public investments in infrastructure generally declined while the focus shifted to the metropolitan "economic growth machines". This paper develops a conceptual framework and agenda for the study of small cities in the global south, their environmental dynamics, governance and politics in the current neoliberal context. While small cities are governed in a neoliberal policy context, they are not central to neoliberalism, and their (environmental) governance therefore seems to differ from that of global cities. Furthermore, "actually existing" neoliberal governance of small cities is shaped by the interplay of regional and local politics and environmental situations. The approach of urban political ecology and the concept of rural-urban linkages are used to consider these socio-ecological processes. The conceptual framework and research agenda are illustrated in the case of India, where the agency of small cities in regard to environmental governance seems to remain limited despite formal political decentralization.

Sequential or concomitant chemotherapy in limited stage small-cell lung cancer.

PURPOSE: Chemotherapy (CT) combined with radiation therapy (RT) is the standard treatment for limited disease small-cell lung cancer (LDSCLC). Many questions including RT dose, fractionation, and sequence of RT/CT administration remain controversial. In this paper, we retrospectively assessed the outcome of patients with LDSCLC treated with radiation of at least 50 Gy.METHODS AND MATERIALS: From December 1997 to January 2006, 69 consecutive patients with LDSCLC were treated at our institutions. Treatment consisted of at least 4 cycles of CT, and 3D conformal thoracic RT. The median age was 61 years (range, 37-78 years). Sequential or concomitant CT/RT was given in 47 (68%) and 22 (32%) of the patients, respectively. The median RT dose was 60 Gy. Prophylactic cranial irradiation (PCI) was administered in 47 (68%) patients.RESULTS: With a median follow-up of 36 months (range, 6-107), 16 patients were alive without disease. The median overall survival time was 24 months, with a 3-year survival rate of 29%. The 3-year disease-free survival (DFS) and loco-regional control (LRC) rates were 23% and 60%, respectively. A better DFS was significantly associated with performance status (PS) 0 (p = 0.004), complete response to treatment (p = 0.03), and PCI group (p = 0.03). A trend towards improved overall survival (OS) was observed for patients who underwent PCI (p = 0.07). Patients treated with sequential CT/RT had a better outcome than those treated with concomitant treatment (3-year DFS rate 27% vs. 13%; p = 0.04). However, PCI was delivered more frequently for the sequential group. No significant dose-response relationship was found in terms of LRC. The multivariate analysis showed that complete response to treatment was the only significant factor for OS.CONCLUSION: Complete response to treatment was the most important factor for OS. A better DFS was significantly associated with the PCI group. We did not find a significant difference in outcome between patients receiving doses of 60 Gy or more and patients receiving 60 Gy or less.

Coculture of bladder urothelial and smooth muscle cells on small intestinal submucosa: potential applications for tissue engineering technology.

PURPOSE: Small intestinal submucosa is a xenogenic, acellular, collagen rich membrane with inherent growth factors that has previously been shown to promote in vivo bladder regeneration. We evaluate in vitro use of small intestinal submucosa to support the individual and combined growth of bladder urothelial cells and smooth muscle cells for potential use in tissue engineering techniques, and in vitro study of the cellular mechanisms involved in bladder regeneration. MATERIALS AND METHODS: Primary cultures of human bladder urothelial cells and smooth muscle cells were established using standard enzymatic digestion or explant techniques. Cultured cells were then seeded on small intestinal submucosa at a density of 1 x 105 cells per cm.2, incubated and harvested at 3, 7, 14 and 28 days. The 5 separate culture methods evaluated were urothelial cells seeded alone on the mucosal surface of small intestinal submucosa, smooth muscle cells seeded alone on the mucosal surface, layered coculture of smooth muscle cells seeded on the mucosal surface followed by urothelial cells 1 hour later, sandwich coculture of smooth muscle cells seeded on the serosal surface followed by seeding of urothelial cells on the mucosal surface 24 hours later, and mixed coculture of urothelial cells and smooth muscle cells mixed and seeded together on the mucosal surface. Following harvesting at the designated time points small intestinal submucosa cell constructs were formalin fixed and processed for routine histology including Masson trichrome staining. Specific cell growth characteristics were studied with particular attention to cell morphology, cell proliferation and layering, cell sorting, presence of a pseudostratified urothelium and matrix penetrance. To aid in the identification of smooth muscle cells and urothelial cells in the coculture groups, immunohistochemical analysis was performed with antibodies to alpha-smooth muscle actin and cytokeratins AE1/AE3. RESULTS: Progressive 3-dimensional growth of urothelial cells and smooth muscle cells occurred in vitro on small intestinal submucosa. When seeded alone urothelial cells and smooth muscle cells grew in several layers with minimal to no matrix penetration. In contrast, layered, mixed and sandwich coculture methods demonstrated significant enhancement of smooth muscle cell penetration of the membrane. The layered and sandwich coculture techniques resulted in organized cell sorting, formation of a well-defined pseudostratified urothelium and multilayered smooth muscle cells with enhanced matrix penetration. With the mixed coculture technique there was no evidence of cell sorting although matrix penetrance by the smooth muscle cells was evident. Immunohistochemical studies demonstrated that urothelial cells and smooth muscle cells maintain the expression of the phenotypic markers of differentiation alpha-smooth muscle actin and cytokeratins AE1/AE3. CONCLUSIONS: Small intestinal submucosa supports the 3-dimensional growth of human bladder cells in vitro. Successful combined growth of bladder cells on small intestinal submucosa with different seeding techniques has important future clinical implications with respect to tissue engineering technology. The results of our study demonstrate that there are important smooth muscle cell-epithelial cell interactions involved in determining the type of in vitro cell growth that occurs on small intestinal submucosa. Small intestinal submucosa is a valuable tool for in vitro study of the cell-cell and cell-matrix interactions that are involved in regeneration and various disease processes of the bladder.