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61.
AM Hempel S Cantlay V Molle SB Wang MJ Naldrett JL Parker DM Richards YG Jung MJ Buttner K Flärdh 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(35):E2371-E2379
In cells that exhibit apical growth, mechanisms that regulate cell polarity are crucial for determination of cellular shape and for the adaptation of growth to intrinsic and extrinsic cues. Broadly conserved pathways control cell polarity in eukaryotes, but less is known about polarly growing prokaryotes. An evolutionarily ancient form of apical growth is found in the filamentous bacteria Streptomyces, and is directed by a polarisome-like complex involving the essential protein DivIVA. We report here that this bacterial polarization machinery is regulated by a eukaryotic-type Ser/Thr protein kinase, AfsK, which localizes to hyphal tips and phosphorylates DivIVA. During normal growth, AfsK regulates hyphal branching by modulating branch-site selection and some aspect of the underlying polarisome-splitting mechanism that controls branching of Streptomyces hyphae. Further, AfsK is activated by signals generated by the arrest of cell wall synthesis and directly communicates this to the polarisome by hyperphosphorylating DivIVA. Induction of high levels of DivIVA phosphorylation by using a constitutively active mutant AfsK causes disassembly of apical polarisomes, followed by establishment of multiple hyphal branches elsewhere in the cell, revealing a profound impact of this kinase on growth polarity. The function of AfsK is reminiscent of the phoshorylation of polarity proteins and polarisome components by Ser/Thr protein kinases in eukaryotes. 相似文献
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Tobias Geis Klaus Marquard Tanja Rödl Christof Reihle Sophie Schirmer Thekla von Kalle Antje Bornemann Ute Hehr Markus Blankenburg 《Neurogenetics》2013,14(3-4):205-213
Defects in dystroglycan post-translational modification result in congenital muscular dystrophy with or without additional eye and brain involvement, are referred to as secondary dystroglycanopathies and have been associated with mutations in 11 different genes encoding glycosyltransferases or associated proteins. However, only one patient with a mutation in the dystroglycan encoding gene DAG1 itself has been described before. We here report a homozygous novel DAG1 missense mutation c.2006G>T predicted to result in the amino acid substitution p.Cys669Phe in the β-subunit of dystroglycan in two Libyan siblings. The affected girls presented with a severe muscle–eye–brain disease-like phenotype with distinct additional findings of macrocephaly and extended bilateral multicystic white matter disease, overlapping with the cerebral findings in patients with megalencephalic leucoencephalopathy with subcortical cysts. This novel clinical phenotype observed in our patients further expands the clinical spectrum of dystroglycanopathies and suggests a role of DAG1 not only for dystroglycanopathies but also for some forms of more extensive and multicystic leucodystrophy. 相似文献
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André Gottschalk Stefan Seelen Sharon Tivey Antje Gottschalk George Rich 《Journal of clinical anesthesia》2013,25(2):85-91
Study ObjectivesTo determine patients' knowledge of the role of the anesthesiologist in the hospital.DesignProspective survey instrument.SettingThree university hospitals (University of Virginia, Charlottesville, VA, USA; St. George Hospital University of New South Wales, Sydney, Australia; and University Hospital, Ruhr-University Bochum, Bochum, Germany).Patients900 patients (300 pts per center) undergoing elective surgery.MeasurementsPatients completed a standardized questionnaire before surgery and before speaking to an anesthesiologist.Main ResultsMost patients knew that anesthesiologists were medical doctors (Charlottesville, 58%; Bochum, 83%; Sydney, 71%). The majority (> 75%) underestimated the amount of training required to become anesthesiologist. While patients recognized the role of anesthesiologists in keeping patients asleep and awakening them, many patients did not understand the anesthesiologists' role in treating intraoperative medical problems. Patients had diverse concerns including infection, awakening during surgery, and failure to awaken, although patients were unclear about who was responsible for treating these issues. Outside the operating room (OR), 71% of patients rated Intensive Care Unit treatment as a duty of the anesthesiologist in Bochum, but fewer (P < 0.05) did so from Charlottesville (42%) and Sydney (49%). Understanding of duties outside the OR (resuscitation, teaching medical students, or chronic pain treatment) was very low (< 50%) in all centers.ConclusionPatients underestimated the training and role of the anesthesiologist in the OR and hospital. 相似文献
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Background: Both orthographic and phonological information from the target word can be appropriate cues in anomia treatment. Furthermore, both types of cues are used very frequently in clinical practice, although their underlying mechanisms of effectiveness and stability are still a matter of debate (e.g., Basso, Marangolo, Piras, & Galluzzi, 2001; Best, Herbert, Hickin, Osborne, & Howard, 2002; Howard & Harding, 1998). Aims: The aim of the study was to examine the mechanisms by which orthographic cues are effective in detail. The study addresses two questions. First, what is the relationship between sublexical transcoding ability and the effectiveness of orthographic cues? And second, what is the relationship between effectiveness of orthographic cues and effectiveness of phonological cues? Methods & Procedures: Three people with chronic aphasia and moderate to severe anomia participated in facilitation of spoken naming, using either the initial phoneme or initial letter of the target word. Both immediate and delayed effects were assessed over six facilitation sessions. Orthographic and phonological cue effects were investigated with regard to regularity of orthographic‐phonological conversion (OPC) of the target's initial letter, and with regard to sub‐lexical and lexical reading and repetition in the participants using a multiple single‐case design (cf. Howard, 2003). Outcomes & Results: In one participant both phonological and orthographic cues produced similar effects. In the other two participants, orthographic cueing effects were present in the absence of phonological cueing effects. With regard to regularity of the initial letter‐phoneme conversion in the orthographic condition, a similar pattern overall was present for regular, ambiguous, and irregular target words, e.g., initial letter cues seemed to be similarly effective in words such as KNIFE (irregular OPC of initial letter) as in words such as KING or DOLL. Conclusions: Initial letter cues are appropriate cues for the effective treatment of anomia as they may produce strong and long‐lasting effects. In contrast to earlier predictions (e.g., Bruce & Howard, 1988), initial letter cues may be effective even in participants where the initial phoneme cue remains totally ineffective. There are likely to be various mechanisms of effectiveness underpinning orthographic cue effects: a sub‐lexical mechanism and a lexical mechanism of effectiveness. 相似文献
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Nasal Staphylococcus aureus carriage is not a risk factor for lower-airway infection in young cystic fibrosis patients 下载免费PDF全文
Ridder-Schaphorn S Ratjen F Dübbers A Häberle J Falk S Küster P Schuster A Mellies U Löwe B Reintjes R Peters G Kahl BC 《Journal of clinical microbiology》2007,45(9):2979-2984
Staphylococcus aureus is one of the first pathogens which often persistently infect the airways of cystic fibrosis (CF) patients. Nasal S. aureus carriage is a risk factor for S. aureus infections in non-CF patients. Topical treatment strategies successfully eradicate nasal S. aureus carriage, thereby decreasing S. aureus infection. A prospective longitudinal multicenter study was conducted to assess whether nasal carriage represents a risk factor for S. aureus colonization of the oropharynx in young CF patients. Cross-sectional analysis revealed a significantly higher prevalence of S. aureus-positive nasal (28/80 [35%] versus 20/109 [18%]; P < 0.01) and oropharyngeal (35/80 [44%] versus 20/109 [18%]; P < 0.001) cultures in children with CF compared to a control group. The first site of S. aureus detection was the nose in 6 patients and the oropharynx in 14 patients, respectively. Longitudinal analysis demonstrated a significantly higher S. aureus prevalence (61/62 [98%] versus 47/62 [76%]; P < 0.001) and persistence (46/62 [74%] versus 31/62 [50%]; P < 0.01) in the oropharynx than in the nose. In CF patients, the oropharynx, and not the nose, was the predominant site of S. aureus infection and persistence. Hence, it is unlikely that CF patients will benefit from topical treatment strategies to eradicate nasal carriage. 相似文献
70.
Ralf Schiel Thomas Perenthaler Sabine Müller Antje Steveling 《Pr?vention und Gesundheitsf?rderung》2018,13(2):170-178