955 resultados para Sentinel organisms
Resumo:
Many neuropeptides are similar in size, amino acid composition and charge to antimicrobial peptides. This study aimed to determine whether the neuropeptides substance P (SP), neurokinin A (NKA), calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP), displayed antimicrobial activity against Streptococcus mutans, Lactobacillus acidophilus, Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. SP, NPY, VIP and CGRP displayed variable degrees of antimicrobial activity against all the pathogens tested with the exception of S. aureus. These antimicrobial activities add a further dimension to the immunomodulatory roles for neuropeptides in the inflammatory and immune responses. (c) 2008 Elsevier B.V. All rights reserved.
Resumo:
Abstract Adaptability to changing circumstances is a key feature of living creatures. Understanding such adaptive processes is central to developing successful autonomous artifacts. In this paper two perspectives are brought to bear on the issue of adaptability. The first is a short term perspective which looks at adaptability in terms of the interactions between the agent and the environment. The second perspective involves a hierarchical evolutionary model which seeks to identify higher-order forms of adaptability based on the concept of adaptive meta-constructs. Task orientated and agent-centered models of adaptive processes in artifacts are considered from these two perspectives. The former isrepresented by the fitness function approach found in evolutionary learning, and the latter in terms of the concepts of empowerment and homeokinesis found in models derived from the self-organizing systems approach. A meta-construct approach to adaptability based on the identification of higher level meta-metrics is also outlined. 2009 Published by Elsevier B.V.
Resumo:
Red algae (Rhodophyta) are an ancient group with unusual morphological, biochemical, and life-history features including a complete absence of flagella. Although the red algae present many opportunities for studying speciation, this has rarely been explicitly addressed. Here, we examine an aspect of paternal gene flow by determining fertilization success of female Neosiphonia harveyi (Ceramiales), which retains a morphological record of all successful and unsuccessful female gametes. High fertilization rates were observed except when there were no males at all within the tidepool, or in a submerged marina environment. Small numbers of reproductive males were able to saturate fertilization rates, suggesting that limited availability of sperm may be less significant in red algae than previously thought. In another member of the Ceramiales, Antithamnion, relatively large chromosomes permit karyological identification of polyploids. The Western Pacific species Antithamnion sparsum is closely related to the diploid species Antithamnion defectum, known only from the Eastern Pacific, and appears to have evolved from it. Molecular evidence suggests that A. sparsum is an autopolyploid, and that the European species known as Antithamnion densum is divergent from the A. sparsum/defectum complex.
Resumo:
A Trust strategy to reduce ciprofloxacin use was implemented at a University hospital. This study aimed to investigate whether the susceptibility of Gram-negative organisms (GNO) to alternative antimicrobials (co-amoxiclav, doxycycline, aztreonam, piperacillin/tazobactam, meropenem and gentamicin) changed, and whether there was any relationship between GNO susceptibility to these antimicrobials and ciprofloxacin usage.
Resumo:
Since the UN report by the Brundtland Committee, sustainability in the built environment has mainly been seen from a technical focus on single buildings or products. With the energy efficiency approaching 100%, fossil resources depleting and a considerable part of the world still in need of better prosperity, the playing field of a technical focus has become very limited. It will most probably not lead to the sustainable development needed to avoid irreversible effects on climate, energy provision and, not least, society.
Cities are complex structures of independently functioning elements, all of which are nevertheless connected to different forms of infrastructure, which provide the necessary sources or solve the release of waste material. With the current ambitions regarding carbon- or energy-neutrality, retreating again to the scale of a building is likely to fail. Within an urban context a single building cannot become fully resource-independent, and need not, from our viewpoint. Cities should be considered as an organism that has the ability to intelligently exchange sources and waste flows. Especially in terms of energy, it can be made clear that the present situation in most cities are undesired: there is simultaneous demand for heat and cold, and in summer a lot of excess energy is lost, which needs to be produced again in winter. The solution for this is a system that intelligently exchanges and stores essential sources, e.g. energy, and that optimally utilises waste flows.
This new approach will be discussed and exemplified. The Rotterdam Energy Approach and Planning (REAP) will be illustrated as a means for urban planning, whereas Swarm Planning will be introduced as another nature-based principle for swift changes towards sustainability
Resumo:
Millipede gut microbiology and decomposition of faecal pellets over a period of eight weeks were studied in the laboratory. Bacterial numbers, carbon and nitrogen content, pH and weight loss were monitored. Heterotrophic bacteria were the most abundant and reached a peak in the first two weeks of decomposition. The amount of carbon was constant while ammonium nitrogen decreased from 1.51 % to 0.03 % after eight weeksThe pH of the pellets was slightly acidic and did not change much during the course of decomposition. A succession of micro-organisms was observed on decomposing pellets. Zygomycetes were replaced by Ascomycetes after 20 days of decomposition. Decomposition was significantly affected by temperature. The rate of decomposition was highest at 35[degree]C .
Resumo:
The role of lymphoscintigraphy in sentinel node biopsy in breast cancer remains debatable. This study assesses the value of lymphoscintigraphy in axillary sentinel node biopsy in women undergoing surgery for breast cancer. Sixty-two patients underwent sentinel node biopsy using a combination of technetium-label led nanocolloid, lymphoscintigraphy and patent blue dye. Lymphoscintigraphy was successful in 84% of patients. Axillary sentinel nodes were identified intraoperatively in all these patients. Internal mammary nodes were identified on lymphoscintigraphy in 19%. Despite lymphoscintigraphy being unsuccessful in 10 patients, axillary sentinel nodes were found intraoperatively in eight of these patients. Lymphoscintigraphy did not increase the detection rate of axillary sentinel nodes and a negative scan did not preclude identification of an axillary sentinel node intraoperatively. This study questions the contribution of lymphoscintigraphy in axillary sentinel node biopsy, however its value may lie in the detection of extra-axillary nodes. (C) 2002 Published by Elsevier Science Ltd.
Resumo:
Sentinel lymph node biopsy has been investigated using combined radioactive colloid and supra vital blue dye in 27 patients with impalpable breast cancers. Sentinel nodes were identified in 25 cases (93%). Seven patients had involved nodes of whom all had a positive sentinel node. Sentinel node biopsy is ideally suited for use in impalpable breast cancers. (C) 2000 Harcourt Publishers Ltd.
Resumo:
Immunohistochemistry of histologically negative axillary lymph nodes in breast-cancer patients resulted in upstaging of the sentinel lymph node in eight (14%) of 52 patients, The resulting information altered clinical management in six of these patients. Thus, this technique may affect clinical decision-making in breast-cancer patients.
Resumo:
Background Sentinel lymph node biopsy is a recently developed, minimally invasive technique for staging the axilla in patients with breast cancer. It has been suggested that this technique will avoid the morbidity associated with more extensive axillary dissection. A wide range of different methods and materials has been employed for lymphatic mapping, but there has been little consensus on the most reliable and reproducible technique.
Methods This is a comprehensive review of all published literature on sentinel node biopsy in breast cancer, using the Medline and Embase databases and cross-referencing of major articles on the subject.
Results and conclusion Sentinel node biopsy is a valid technique in breast cancer management, providing valuable axillary staging information. The optimal technique of lymphatic mapping utilizes a combination of vital blue dye and radiolabelled colloid. However, there remain controversial issues which require to be resolved before sentinel node biopsy becomes a widely accepted part of breast cancer care.
Resumo:
Burkholderia cepacia complex organisms are important transmissible pathogens found in cystic fibrosis (CF) patients. In recent years, the rates of cross-infection of epidemic strains have declined due to effective infection control efforts. However, cases of sporadic B. cepacia complex infection continue to occur in some centers. The acquisition pathways and clinical outcomes of sporadic B. cepacia complex infection are unclear. We sought to determine the patient clinical characteristics, outcomes, incidence, and genotypic relatedness for all cases of B. cepacia complex infection at two CF centers. We also sought to study the external conditions that influence the acquisition of infection. From 2001 to 2011, 67 individual organisms were cultured from the respiratory samples of 64 patients. Sixty-five percent of the patients were adults, in whom chronic infections were more common (68%) (P = 0.006). The incidence of B. cepacia complex infection increased by a mean of 12% (95% confidence interval [CI], 3 to 23%) per year. The rates of transplantation and death were similar in the incident cases who developed chronic infection compared to those in patients with chronic Pseudomonas aeruginosa infection. Multilocus sequence typing revealed 50 individual strains from 65 isolates. Overall, 85% of the patients were infected with unique strains, suggesting sporadic acquisition of infection. The yearly incidence of nonepidemic B. cepacia complex infection was positively correlated with the amount of rainfall in the two sites examined: subtropical Brisbane (r = 0.65, P = 0.031) and tropical Townsville (r = 0.82, P = 0.002). This study demonstrates that despite strict cohort segregation, new cases of unrelated B. cepacia complex infection continue to occur. These data also support an environmental origin of infection and suggest that climate conditions may be associated with the acquisition of B. cepacia complex infections.