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101.
Contactins are a group of cell adhesion molecules that are mainly expressed in the brain and play pivotal roles in the organization of axonal domains, axonal guidance, neuritogenesis, neuronal development, synapse formation and plasticity, axo-glia interactions and neural regeneration. Contactins comprise a family of six members. Their absence leads to malformed axons and impaired nerve conduction. Contactin mediated protein complex formation is critical for the organization of the axon in early central nervous system development. Mutations and differential expression of contactins have been identified in neuro-developmental or neurological disorders. Taken together, contactins are extensively studied in the context of nervous system development. This review summarizes the physiological roles of all six members of the Contactin family in neurodevelopment as well as their involvement in neurological/neurodevelopmental disorders. 相似文献
102.
Lewden C Raffi F Cuzin L Cailleton V Vildé JL Chêne G Allavena C Salamon R Leport C 《The Journal of infectious diseases》2002,186(5):710-714
This study attempted to identify factors associated with mortality among human immunodeficiency virus (HIV)-infected adults starting a protease inhibitor (PI)-containing therapy. Among 1155 patients consecutively enrolled in the APROCO study between May 1997 and June 1998, clinical characteristics were as follows: median age, 36 years; median baseline CD4 cell count, 288 cells/mm(3); and median baseline plasma HIV RNA load, 4.4 log(10) copies/mL. After a median follow-up of 27 months, 48 deaths had occurred, of which 44% were related to acquired immune deficiency syndrome. The mortality rate was 2.9% at 12 months. When both data at baseline and data at 4 months after the start of PI therapy were considered, factors independently associated with mortality were (Cox model) low baseline plasma creatinine level, low school education level, low CD4 cell count at 4 months, low hemoglobin level, and elevated hepatic transaminase levels. Thus, social context plus clinical and biologic data, including the 4-month response to treatment, must be considered in treatment of HIV-infected patients. 相似文献
103.
Katz JN Phillips CB Baron JA Fossel AH Mahomed NN Barrett J Lingard EA Harris WH Poss R Lew RA Guadagnoli E Wright EA Losina E 《Arthritis and rheumatism》2003,48(2):560-568
OBJECTIVE: To evaluate whether hospital volume and surgeon volume of total hip replacements (THRs) are associated with patient-reported functional status and satisfaction with surgery 3 years postoperatively. METHODS: We performed a population-based cohort study of a stratified random sample of Medicare beneficiaries who underwent elective primary or revision THR in Ohio, Pennsylvania, or Colorado in 1995. The primary outcomes were the self-reported Harris hip score and a validated scale measuring satisfaction with the results of surgery. Both outcomes were assessed 3 years postoperatively. Hospital volume was defined as the aggregate number of elective primary and revision THRs performed on Medicare beneficiaries in the hospital in 1995. High-volume hospitals were defined as those in which >100 such procedures are performed annually, and low-volume centers were defined as those in which =12 procedures (primary THR cohort) or =30 procedures (revision cohort) are performed annually. RESULTS: In unadjusted analyses, patients who underwent surgery in low-volume centers had worse functional status 3 years following primary and revision THR compared with patients whose surgery was performed in higher-volume centers. Patients whose revision THR was performed by a low-volume surgeon also had worse function. After adjustment for sociodemographic and clinical variables, however, the association between higher hospital volume and better functional status following primary THR was weak and statistically nonsignificant, and no statistically significant or clinically important associations between hospital or surgeon volume and functional status following revision THR was observed. Patients who underwent elective primary THR in low-volume centers were more likely to be dissatisfied with the results of surgery compared with patients whose surgeries were performed in high-volume centers. Similarly, patients whose surgeons performed =12 procedures per year were more likely to be dissatisfied with the results of revision THR than were patients whose surgeons performed >12 procedures per year. CONCLUSION: Hospital volume and surgeon volume have little effect on 3-year functional outcome following THR, after adjusting for patient sociodemographic and select clinical characteristics. However, satisfaction with primary THR is greater among patients who underwent surgery in high-volume centers, and satisfaction with revisions is greater among patients whose operations were performed by higher-volume surgeons. Referring clinicians should incorporate these findings into their discussion of referral choices with patients considering THR. Conclusions regarding the effect of volume on longevity of the implants must await longer-term followup studies. Finally, further research is warranted to better understand the association between hospital and surgeon procedure volume and patient satisfaction with surgery. 相似文献
104.
Esther M. Wesselink MD Masieh Abawi MD PhD Nynke H. M. Kooistra MD PhD Teus H. Kappen MD PhD Pierfrancesco Agostoni MD PhD Marielle Emmelot-Vonk MD PhD Wietze Pasma PhD Wilton A. van Klei MD PhD Romy C. van Jaarsveld MSc Charlotte S. van Dongen MSc Pieter A. F. M. Doevendans MD PhD Arjen J. C. Slooter MD PhD Pieter R. Stella MD PhD 《Journal of the American Geriatrics Society》2021,69(11):3177-3185
105.
Sridhar Ravi Tim Siesenop Olivier Bertrand Liang Li Charlotte Doussot William H. Warren Stacey A. Combes Martin Egelhaaf 《Proceedings of the National Academy of Sciences of the United States of America》2020,117(49):31494
Animals that move through complex habitats must frequently contend with obstacles in their path. Humans and other highly cognitive vertebrates avoid collisions by perceiving the relationship between the layout of their surroundings and the properties of their own body profile and action capacity. It is unknown whether insects, which have much smaller brains, possess such abilities. We used bumblebees, which vary widely in body size and regularly forage in dense vegetation, to investigate whether flying insects consider their own size when interacting with their surroundings. Bumblebees trained to fly in a tunnel were sporadically presented with an obstructing wall containing a gap that varied in width. Bees successfully flew through narrow gaps, even those that were much smaller than their wingspans, by first performing lateral scanning (side-to-side flights) to visually assess the aperture. Bees then reoriented their in-flight posture (i.e., yaw or heading angle) while passing through, minimizing their projected frontal width and mitigating collisions; in extreme cases, bees flew entirely sideways through the gap. Both the time that bees spent scanning during their approach and the extent to which they reoriented themselves to pass through the gap were determined not by the absolute size of the gap, but by the size of the gap relative to each bee’s own wingspan. Our findings suggest that, similar to humans and other vertebrates, flying bumblebees perceive the affordance of their surroundings relative their body size and form to navigate safely through complex environments.Avoiding collisions with obstacles is a requirement for successful locomotion through most natural habitats, where the physical environment is often cluttered and complex. At the most elemental level, animals moving through their environments need to identify gaps between obstacles and assess their passability. In this context, whether a gap between obstacles “affords” passing is determined by the fit between the spatial layout of the environment and the properties of the organism’s form and action system, as described in classical theses on affordances (1–3). In humans and other highly cognitive vertebrates, the perception of affordances for performing visually guided actions such as grasping, passing through apertures, and climbing is actively shaped throughout ontogeny, as body size, configuration, and experience change (2, 4–7). However, the strategies used by animals with much smaller brains, such as insects, to contend with the challenges of navigating environmental clutter and spatial heterogeneity are unclear.We used bumblebees to investigate whether flying insects take into account their own size during interactions with their surroundings. Bumblebees and other volant insects that travel long distances (8) and frequently encounter regions of dense clutter can be expected to exhibit strategies to avoid collisions, because damage to sensitive structures such as the wings is irreparable and adversely impacts flight performance and lifespan (9, 10). For an animal attempting to navigate through tight spaces, perceiving the relationship between the layout of the environment and its own size can help inform the animal of its potential for collision-free passage. Bumblebee workers naturally display large variation in body size within a given colony (11, 12), and thus are particularly suitable models for testing the effects of insect body size on aerial navigation and for determining whether insects perceive the external environment in relation to their own spatial dimensions.To elicit repeatable flight behavior, we trained foraging bumblebees to fly within a 1.6 × 0.3 × 0.3 m (l × w × h) flight tunnel that separated the hive from a foraging arena (Materials and Methods, SI Appendix, Fig. S1, and Movie S1). After bees were habituated to the setup and began foraging normally, we placed an unexpected obstacle within the tunnel, consisting of a thin vertical wall (5-mm thickness) spanning the tunnel’s width and height. The obstructing wall contained a rectangular gap starting midway up and extending to the top of the wall (Materials and Methods, SI Appendix, Fig. S1, and Movie S1). The width of the gap was varied between 20 and 60 mm over different trials, with the presenting order of gap sizes chosen randomly. A high-speed camera placed above the tunnel was used to record bees’ instantaneous positions, heading/yaw orientations (Fig. 1A), and trajectories as they approached the obstructing wall and passed through the gap. To prevent bees from becoming familiar with the experimental paradigm, the obstructing wall was removed after each flight recording. In total, we recorded and analyzed over 400 flights of bees of varying body sizes flying through seven different gap sizes (SI Appendix, Table S1). For the population of bees recorded, wingspan was the longest dimension of the body and it varied linearly by a factor of 1.9 compared to their longitudinal body length while in flight (SI Appendix, Fig. S2A).Open in a separate windowFig. 1.Bumblebees can safely fly through gaps that are smaller than their wingspan. (A and B) Illustrations indicating the wingspan of bees (Ws), the size of the gap (Gs), and the positive and negative yaw (heading) angles for bees flying in the tunnel, respectively. (C) Schematic illustration of the flight of a bee flying through a gap that is much wider than its wingspan. (D) The instantaneous yaw angle of bee shown in C. (E) Schematic illustrationof the flightofabeeflying through a gap that is smaller than its wingspan. (F) The instantaneous yaw angle of bee shown in E. Flights, in both cases (C and E), consisted of approach, lateral peering, and—for the smaller gap size (E)—body reorientation (an increase in yaw angle) while passing through the gap. The differences in reorientation behavior can be noted at x = 0 (location of the gap), whereas in F the bee displays a large increase in yaw angle that reorients its body to pass through the small gap, and body reorientation in D is minimal. For the flight shown in C and D, Ws = 27.5 mm and Gs = 50 mm, while for the flight shown in E and F, Ws = 27 mm and Gs = 25 mm. 相似文献
106.
A phase I trial and viral clearance study of reovirus (Reolysin) in children with relapsed or refractory extra‐cranial solid tumors: A Children's Oncology Group Phase I Consortium report 下载免费PDF全文
107.
Charlotte Pauwels Alexandra Roren Adrien Gautier Jonathan Linières François Rannou Serge Poiraudeau Christelle Nguyen 《Annals of physical and rehabilitation medicine》2018,61(3):144-150
Background
Lumbar-flexion-based endurance training, namely cycling, could be effective in reducing pain and improving function and health-related quality of life in older people with chronic low back pain.Objectives
To assess barriers and facilitators to home-based cycling in older patients with lumbar spinal stenosis (LSS).Methods
We conducted a retrospective mixed-method study. Patients ≥ 50 years old followed up for LSS from November 2015 to June 2016 in a French tertiary care center were screened. The intervention consisted of a single supervised session followed by home-based sessions of cycling, with dose (number of sessions and duration, distance and power per session) self-determined by patient preference. The primary outcome was assessed by a qualitative approach using semi-structured interviews at baseline and 3 months and was the identification of barriers and facilitators to the intervention. Secondary outcomes were assessed by a quantitative approach and were adherence monitored by a USB stick connected to the bicycle, burden of treatment assessed by the Exercise Therapy Burden Questionnaire (ETBQ) and clinical efficacy assessed by change in lumbar pain, radicular pain, disability, spine-specific activity limitation and maximum walking distance at 3 months.Results
Overall, 15 patients were included and data for 12 were analyzed at 3 months. At baseline, the mean age was 70.9 years (95% CI: 64.9–76.8) and 9/15 patients (60.0%) were women. Barriers to cycling were fear of pain and fatigue, a too large bicycle, burden of hospital follow-up and lack of time and motivation. Facilitators were clinical improvement, surveillance and ease-of-use of the bicycle. Adherence remained stable overtime. The burden of treatment was low [mean ETBQ score: 21.0 (95% confidence interval: 11.5–30.5)]. At 3 months, 7/12 patients (58.3%) self-reported clinical improvement, with reduced radicular pain and disability [mean absolute differences: ?27.5 (?43.3 to ?11.7), P < 0.01 and ?17.5 (?32.1 to ?2.9), P = 0.01, respectively].Conclusions
For people with LSS, home-based cycling is a feasible intervention. 相似文献108.
109.
110.