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1.
Woon-Man Kung Shuo-Tsung Chen Chung-Hsiang Lin Yu-Mei Lu Tzu-Hsuan Chen Muh-Shi Lin 《PloS one》2013,8(10)
Background
Difficulty exists in scalp adaptation for cranioplasty with customized computer-assisted design/manufacturing (CAD/CAM) implant in situations of excessive wound tension and sub-cranioplasty dead space. To solve this clinical problem, the CAD/CAM technique should include algorithms to reconstruct a depressed contour to cover the skull defect. Satisfactory CAM-derived alloplastic implants are based on highly accurate three-dimensional (3-D) CAD modeling. Thus, it is quite important to establish a symmetrically regular CAD/CAM reconstruction prior to depressing the contour. The purpose of this study is to verify the aesthetic outcomes of CAD models with regular contours using cranial index of symmetry (CIS).Materials and methods
From January 2011 to June 2012, decompressive craniectomy (DC) was performed for 15 consecutive patients in our institute. 3-D CAD models of skull defects were reconstructed using commercial software. These models were checked in terms of symmetry by CIS scores.Results
CIS scores of CAD reconstructions were 99.24±0.004% (range 98.47–99.84). CIS scores of these CAD models were statistically significantly greater than 95%, identical to 99.5%, but lower than 99.6% (p<0.001, p = 0.064, p = 0.021 respectively, Wilcoxon matched pairs signed rank test). These data evidenced the highly accurate symmetry of these CAD models with regular contours.Conclusions
CIS calculation is beneficial to assess aesthetic outcomes of CAD-reconstructed skulls in terms of cranial symmetry. This enables further accurate CAD models and CAM cranial implants with depressed contours, which are essential in patients with difficult scalp adaptation. 相似文献2.
Background
Fetal alcohol spectrum disorders (FASD) are the leading cause of mental retardation in the western world and children with FASD present altered somatosensory, auditory and visual processing. There is growing evidence that some of these sensory processing problems may be related to altered cortical maps caused by impaired developmental neuronal plasticity.Methodology/Principal Findings
Here we show that the primary visual cortex of ferrets exposed to alcohol during the third trimester equivalent of human gestation have decreased CREB phosphorylation and poor orientation selectivity revealed by western blotting, optical imaging of intrinsic signals and single-unit extracellular recording techniques. Treating animals several days after the period of alcohol exposure with a phosphodiesterase type 1 inhibitor (Vinpocetine) increased CREB phosphorylation and restored orientation selectivity columns and neuronal orientation tuning.Conclusions/Significance
These findings suggest that CREB function is important for the maturation of orientation selectivity and that plasticity enhancement by vinpocetine may play a role in the treatment of sensory problems in FASD. 相似文献3.
Background
Early deafness leads to enhanced attention in the visual periphery. Yet, whether this enhancement confers advantages in everyday life remains unknown, as deaf individuals have been shown to be more distracted by irrelevant information in the periphery than their hearing peers. Here, we show that, in a complex attentional task, a performance advantage results for deaf individuals.Methodology/Principal Findings
We employed the Useful Field of View (UFOV) which requires central target identification concurrent with peripheral target localization in the presence of distractors – a divided, selective attention task. First, the comparison of deaf and hearing adults with or without sign language skills establishes that deafness and not sign language use drives UFOV enhancement. Second, UFOV performance was enhanced in deaf children, but only after 11 years of age.Conclusions/Significance
This work demonstrates that, following early auditory deprivation, visual attention resources toward the periphery slowly get augmented to eventually result in a clear behavioral advantage by pre-adolescence on a selective visual attention task. 相似文献4.
Ryo Asaoka 《PloS one》2013,8(8)
Purpose
To measure progression of the visual field (VF) mean deviation (MD) index in longitudinal 10-2 VFs more accurately, by adding information from 24-2 VFs using Lasso regression.Methods
A training dataset consisted of 138 eyes from 97 patients with glaucoma or ocular hypertension and a testing dataset consisted of 40 eyes from 34 patients with glaucoma or ocular hypertension. The Lasso method was used to predict total deviation (TD) values in training patients’ 10-2 VFs based on information from their 24-2 VFs (52 TD values, foveal sensitivity and mean deviation MD). Then, the MD of each patient’s 10-2 VF was estimated as the average of these Lasso-predicted TD values (10-2 VF ‘Lasso MD’; LMD). Finally, linear regression was applied to each testing patient’s series of longitudinal 10-2 VF MDs with and without additional Lasso-derived LMDs in order to predict future MDs not included in the regression analysis. Absolute prediction errors were compared when only actual 10-2 MDs were regressed against when a combination of actual 10-2 MDs and LMDs were regressed.Results
The average absolute prediction error was significantly smaller for the novel method incorporating LMDs (range: 1.6 to 1.8 dB) compared with the standard approach (range: 1.7 to 3.4 dB) (p<0.05, ANOVA test).Conclusions
Deriving 10-2 VF MD values from 24-2 VFs improves the prediction accuracy of progression. This approach will help clinicians to predict patients’ visual function in the parafoveal area. 相似文献5.
SL Merbs JC Harding SD Cassard BE Munoz SK West EW Gower 《PLoS neglected tropical diseases》2012,6(7):e1718
Background
Surgical technique, including suture placement and tension, is believed to contribute to the outcome of bilamellar tarsal rotation surgery for trachomatous trichiasis. However, the immediate post-operative appearance that minimizes the chance of recurrence and other adverse outcomes has not been investigated.Methodology/Principal Findings
To explore whether the degree of correction immediately after surgery is predictive of surgical outcome at the 6-week post-operative visit, photographs taken immediately after surgery were used to predict surgical outcomes, including the severity of eyelid contour abnormality and trichiasis recurrence. Both eyelid contour abnormalities and recurrence were accurately predicted from the immediate post-operative photographs by an experienced oculoplastic surgeon 85% and 70% of the time, respectively. Participants with a “slight over-correction” that resulted in no eyelid contour abnormality and no recurrence were used to identify immediate post-operative contours that lead to a successful surgical outcome.Conclusions/Significance
The immediate post-operative eyelid contour is an important indicator of post-operative success of BLTR surgery. Based upon our findings, we developed a Surgery Photocard. This card illustrates some examples of immediate post-surgical appearances, which led to a successful outcome, as well as sub-optimal appearances, which led to poor surgical outcomes. The card also provides suggestions for improving the appearance by adjusting the suture placement or tension based upon standard oculoplastic principles. 相似文献6.
Background
The aims of this study were to investigate whether the preoperative hematologic markers, the neutrophil-lymphocyte ratio (NLR) or the platelet-lymphocyte ratio (PLR) were prognostic indicators and to develop a novel risk stratification model in pN0 non-small-cell lung cancer (NSCLC).Methods
We performed a retrospective analysis of 400 consecutive pN0 NSCLC patients. Prognostic values were evaluated by Cox proportional hazard model analyses and patients were stratified according to relative risks for patients’ survival.Results
During the follow-up, 117 patients had cancer recurrence, and 86 patients died. In univariate analysis, age, gender, smoke status and tumor size as well as WBC, NEU, LYM, PLR and NLR were significantly associated with patients’ prognosis. In multivariate analysis, age, tumor size and NLR were independent predictors for patients’ overall survival (P = 0.024, 0.001, and 0.002 respectively). PLR didn’t associated with patients’ survival in multivariate analysis. Patients were stratified into 3 risk groups and the differences among the groups were significant according to disease free survival and overall survival (P = 0.000 and 0.000 respectively).Conclusions
We confirmed that NLR other than PLR was an independent prognostic factor. Combination of NLR, age and tumor size could stratify pN0 NSCLC patients into 3 risk groups and enabled us to develop a novel risk stratification model. 相似文献7.
8.
Upendra Bhojani Narayanan Devedasan Arima Mishra Stefaan De Henauw Patrick Kolsteren Bart Criel 《PloS one》2014,9(9)
Background
Weak health systems in low- and middle-income countries are recognized as the major constraint in responding to the rising burden of chronic conditions. Despite recognition by global actors for the need for research on health systems, little attention has been given to the role played by local health systems. We aim to analyze a mixed local health system to identify the main challenges in delivering quality care for diabetes mellitus type 2.Methods
We used the health system dynamics framework to analyze a health system in KG Halli, a poor urban neighborhood in South India. We conducted semi-structured interviews with healthcare providers located in and around the neighborhood who provide care to diabetes patients: three specialist and 13 non-specialist doctors, two pharmacists, and one laboratory technician. Observations at the health facilities were recorded in a field diary. Data were analyzed through thematic analysis.Result
There is a lack of functional referral systems and a considerable overlap in provision of outpatient care for diabetes across the different levels of healthcare services in KG Halli. Inadequate use of patients’ medical records and lack of standard treatment protocols affect clinical decision-making. The poor regulation of the private sector, poor systemic coordination across healthcare providers and healthcare delivery platforms, widespread practice of bribery and absence of formal grievance redress platforms affect effective leadership and governance. There appears to be a trust deficit among patients and healthcare providers. The private sector, with a majority of healthcare providers lacking adequate training, operates to maximize profit, and healthcare for the poor is at best seen as charity.Conclusions
Systemic impediments in local health systems hinder the delivery of quality diabetes care to the urban poor. There is an urgent need to address these weaknesses in order to improve care for diabetes and other chronic conditions. 相似文献9.
10.
Background
The visual system adjusts to changes in the environment, as well as to changes within the observer, adapting continuously to maintain a match between visual coding and visual environment. We evaluated whether the perception of oriented blur is biased by the native astigmatism, and studied the time course of the after-effects following spectacle correction of astigmatism in habitually non-corrected astigmats.Methods and Findings
We tested potential shifts of the perceptual judgments of blur orientation in 21 subjects. The psychophysical test consisted on a single interval orientation identification task in order to measure the perceived isotropic point (astigmatism level for which the image did not appear oriented to the subject) from images artificially blurred with constant blur strength (B = 1.5 D), while modifying the orientation of the blur according to the axis of natural astigmatism of the subjects. Measurements were performed after neutral (gray field) adaptation on naked eyes under full correction of low and high order aberrations. Longitudinal measurements (up to 6 months) were performed in three groups of subjects: non-astigmats and corrected and uncorrected astigmats. Uncorrected astigmats were provided with proper astigmatic correction immediately after the first session. Non-astigmats did not show significant bias in their perceived neutral point, while in astigmatic subjects the perceived neutral point was significantly biased, typically towards their axis of natural astigmatism. Previously uncorrected astigmats shifted significantly their perceived neutral point towards more isotropic images shortly (2 hours) after astigmatic correction wear, and, once stabilized, remained constant after 6 months. The shift of the perceived neutral point after correction of astigmatism was highly correlated with the amount of natural astigmatism.Conclusions
Non-corrected astigmats appear to be naturally adapted to their astigmatism, and astigmatic correction significantly changes their perception of their neutral point, even after a brief period of adaptation. 相似文献11.
Background
Repetitive transcranial magnetic stimulation (rTMS) at certain frequencies increases thresholds for motor-evoked potentials and phosphenes following stimulation of cortex. Consequently rTMS is often assumed to introduce a “virtual lesion” in stimulated brain regions, with correspondingly diminished behavioral performance.Methodology/Principal Findings
Here we investigated the effects of rTMS to visual cortex on subjects'' ability to perform visual psychophysical tasks. Contrary to expectations of a visual deficit, we find that rTMS often improves the discrimination of visual features. For coarse orientation tasks, discrimination of a static stimulus improved consistently following theta-burst stimulation of the occipital lobe. Using a reaction-time task, we found that these improvements occurred throughout the visual field and lasted beyond one hour post-rTMS. Low-frequency (1 Hz) stimulation yielded similar improvements. In contrast, we did not find consistent effects of rTMS on performance in a fine orientation discrimination task.Conclusions/Significance
Overall our results suggest that rTMS generally improves or has no effect on visual acuity, with the nature of the effect depending on the type of stimulation and the task. We interpret our results in the context of an ideal-observer model of visual perception. 相似文献12.
Background
Trust in health care has been intensely researched in resource rich settings. Some studies in resource poor settings suggest that the dimensions and determinants of trust are likely to be different.Objectives
This study was done as a qualitative exploration of the dimensions and determinants of trust in health care in Tamil Nadu, a state in south India to assess the differences from dimensions and determinants in resource rich settings.Methodology
The participants included people belonging to marginalized communities with poor access to health care services and living in conditions of resource deprivation. A total of thirty five in depth interviews were conducted. The interviews were summarized and transcribed and data were analyzed following thematic analysis and grounded theory approach.Results
The key dimensions of trust in health care identified during the interviews were perceived competence, assurance of treatment irrespective of ability to pay or at any time of the day, patients’ willingness to accept drawbacks in health care, loyalty to the physician and respect for the physician. Comfort with the physician and health facility, personal involvement of the doctor with the patient, behavior and approach of doctor, economic factors, and health awareness were identified as factors determining the levels of trust in health care.Conclusions
The dimensions and determinants of trust in health care in resource poor settings are different from that in resource rich settings. There is a need to develop scales to measure trust in health care in resource poor settings using these specific dimensions and determinants. 相似文献13.
Introduction
The National Institute for Health and Clinical Excellence guidelines recommend acupuncture as a clinically effective treatment for chronic back pain. However, there is insufficient knowledge of what factors contribute to patients’ positive and negative experiences of acupuncture, and how those factors interact in terms of the acceptability of treatment. This study used patient interviews following acupuncture treatment for back pain to identify, understand and describe the elements that contribute or detract from acceptability of treatment.Methods
The study used semi-structured interviews. Twelve patients were interviewed using an interview schedule as a sub-study nested within a randomised controlled trial of acupuncture for chronic back pain. The interviews were analysed using thematic analysis.Results and Discussion
Three over-arching themes emerged from the analysis. The first entitled facilitators of acceptability contained five subthemes; experience of pain relief, improvements in physical activity, relaxation, psychological benefit, reduced reliance on medication. The second over-arching theme identified barriers to acceptability, which included needle-related discomfort and temporary worsening of symptoms, pressure to continue treatment and financial cost. The third over-arching theme comprised mediators of acceptability, which included pre-treatment mediators such as expectation and previous experience, and treatment-related mediators of time, therapeutic alliance, lifestyle advice and the patient’s active involvement in recovery. These themes inform our understanding of the acceptability of acupuncture to patients with low back pain.Conclusion
The acceptability of acupuncture treatment for low back pain is complex and multifaceted. The therapeutic relationship between the practitioner and patient emerged as a strong driver for acceptability, and as a useful vehicle to develop the patients’ self-efficacy in pain management in the longer term. Unpleasant treatment related effects do not necessarily detract from patients’ overall perception of acceptability. 相似文献14.
Background
The mechanisms of drug-induced visions are poorly understood. Very few serotonergic hallucinogens have been studied in humans in decades, despite widespread use of these drugs and potential relevance of their mechanisms to hallucinations occurring in psychiatric and neurological disorders.Methodology/Principal Findings
We investigated the mechanisms of hallucinogen-induced visions by measuring the visual and perceptual effects of the hallucinogenic serotonin 5-HT2AR receptor agonist and monoamine releaser, 3,4-methylenedioxyamphetamine (MDA), in a double-blind placebo-controlled study. We found that MDA increased self-report measures of mystical-type experience and other hallucinogen-like effects, including reported visual alterations. MDA produced a significant increase in closed-eye visions (CEVs), with considerable individual variation. Magnitude of CEVs after MDA was associated with lower performance on measures of contour integration and object recognition.Conclusions/Significance
Drug-induced visions may have greater intensity in people with poor sensory or perceptual processing, suggesting common mechanisms with other hallucinatory syndromes. MDA is a potential tool to investigate mystical experiences and visual perception.Trial Registration
Clinicaltrials.gov NCT00823407 相似文献15.
Brian P. Keane Hongjing Lu Thomas V. Papathomas Steven M. Silverstein Philip J. Kellman 《PloS one》2013,8(6)
Background
A classification image (CI) technique has shown that static luminance noise near visually completed contours affects the discrimination of fat and thin Kanizsa shapes. These influential noise regions were proposed to reveal “behavioral receptive fields” of completed contours–the same regions to which early cortical cells respond in neurophysiological studies of contour completion. Here, we hypothesized that 1) influential noise regions correspond to the surfaces that distinguish fat and thin shapes (hereafter, key regions); and 2) key region noise biases a “fat” response to the extent that its contrast polarity (lighter or darker than background) matches the shape''s filled-in surface color.Results
To test our hypothesis, we had observers discriminate fat and thin noise-embedded rectangles that were defined by either illusory or luminance-defined contours (Experiment 1). Surrounding elements (“inducers”) caused the shapes to appear either lighter or darker than the background–a process sometimes referred to as lightness induction. For both illusory and luminance-defined rectangles, key region noise biased a fat response to the extent that its contrast polarity (light or dark) matched the induced surface color. When lightness induction was minimized, luminance noise had no consistent influence on shape discrimination. This pattern arose when pixels immediately adjacent to the discriminated boundaries were excluded from the analysis (Experiment 2) and also when the noise was restricted to the key regions so that the noise never overlapped with the physically visible edges (Experiment 3). The lightness effects did not occur in the absence of enclosing boundaries (Experiment 4).Conclusions
Under noisy conditions, lightness induction alters visually completed shape. Moreover, behavioral receptive fields derived in CI studies do not correspond to contours per se but to filled-in surface regions contained by those contours. The relevance of lightness to two-dimensional shape completion supplies a new constraint for models of object perception. 相似文献16.
Purpose
We sought brain activity that predicts visual consciousness.Methods
We used electroencephalography (EEG) to measure brain activity to a 1000-ms display of sine-wave gratings, oriented vertically in one eye and horizontally in the other. This display yields binocular rivalry: irregular alternations in visual consciousness between the images viewed by the eyes. We replaced both gratings with 200 ms of darkness, the gap, before showing a second display of the same rival gratings for another 1000 ms. We followed this by a 1000-ms mask then a 2000-ms inter-trial interval (ITI). Eleven participants pressed keys after the second display in numerous trials to say whether the orientation of the visible grating changed from before to after the gap or not. Each participant also responded to numerous non-rivalry trials in which the gratings had identical orientations for the two eyes and for which the orientation of both either changed physically after the gap or did not.Results
We found that greater activity from lateral occipital-parietal-temporal areas about 180 ms after initial onset of rival stimuli predicted a change in visual consciousness more than 1000 ms later, on re-presentation of the rival stimuli. We also found that less activity from parietal, central, and frontal electrodes about 400 ms after initial onset of rival stimuli predicted a change in visual consciousness about 800 ms later, on re-presentation of the rival stimuli. There was no such predictive activity when the change in visual consciousness occurred because the stimuli changed physically.Conclusion
We found early EEG activity that predicted later visual consciousness. Predictive activity 180 ms after onset of the first display may reflect adaption of the neurons mediating visual consciousness in our displays. Predictive activity 400 ms after onset of the first display may reflect a less-reliable brain state mediating visual consciousness. 相似文献17.
Iwona Gisterek Ewelina Lata Agnieszka Halon Rafal Matkowski Jolanta Szelachowska Przemyslaw Biecek Jan Kornafel 《Reports of Practical Oncology and Radiotherapy》2011,16(5):173-177
Background
Hepatocyte growth factor plays an important role in tumor growth, metastasis and angiogenesis. C-met is HGF''s high affinity receptor.Aim
The aim of the study was to assess the correlations between c-met expression and clinic-pathological factors in breast cancer tissues. Furthermore, the purpose of the study was to evaluate the prognostic value of the hepatocyte growth factor receptor (HGFR, c-met) expressions in homogenous group of breast cancer patients.Materials and methods
Tumor samples were collected from 302 patients with breast carcinoma treated with primary surgery. We have assessed the percentage of tumor cells with c-met expression, the intensity of reaction and the ratio of these two factors—immunoreactivity according to the Remmele score.Results
We have observed no correlations between HGFR immunoreactivities and clinical parameters (tumor size, grade, axillary lymph node status, age). In 5-year observation we have found prognostic value of assessing c-met immunoreactivity in primary tumor.Conclusion
Our study has revealed prognostic value of c-met. Unlike in other authors’ studies, our patients’ group is very homogenous which might contribute to obtained results. 相似文献18.
Tetyana L. Vasylyeva Ruchi Singh Christopher Sheehan Sudha P. Chennasamudram Anne P. Hernandez 《PloS one》2013,8(7)
Background
Chronically ill children and adolescents comprise a vulnerable population that requires specific considerations in order to positively impact their treatment outcome. Pediatric renal patients can be non-compliant and also forgetful in taking their medications.Objective
The objectives of the study were to (a) assess medication adherence and (b) to identify emotionality and variables that influence non-adherence by use of “The Child & Adolescent Adherence to Medication Questionnaire” (CAAMQ), which was constructed at Texas Tech University Health Sciences Center.Methods
Pediatric renal patients from 10 to 21 years-of-age, taking three or more medications, for longer than a three-month period, were eligible to complete the CAAMQ.Results
Thirty-four patients participated in the study. Many of the respondents had problems remembering to take their medications on weekends (P = 0.021). The majority of the patients stated that they were not bothered about having to take their medications (70.6%); and that taking pills did not interfere with their daily activities (85.3%). Open-ended questions in the CAAMQ identified patients’ feelings of sadness, distress, and the importance of strong family support systems. The study participants reported that they preferred to take their medications at school, in the nurses’ office or in a place where privacy was assured. The results indicated that Prednisone was the most disliked of all of the medications. Female patients were more reactive and secretive than males regarding peers knowing about their disease and medication schedules (P<0.017).Conclusions
Non-adherence in pediatric patients is a complex and serious problem, which ultimately affects the patients’ health. Privacy and daily routine were found to impact the patients’ adherence to medications. Creative and individualized reminders for teenagers need to be developed and validated. Further studies that take into consideration developmental and motivational factors may help researchers identify modifiable psychosocial predictors that will lead to improved medication adherence. 相似文献19.
Background
The simultaneous tracking and identification of multiple moving objects encountered in everyday life requires one to correctly bind identities to objects. In the present study, we investigated the role of spatial configuration made by multiple targets when observers are asked to track multiple moving objects with distinct identities.Methodology/Principal Findings
The overall spatial configuration made by the targets was manipulated: In the constant condition, the configuration remained as a virtual convex polygon throughout the tracking, and in the collapsed condition, one of the moving targets (critical target) crossed over an edge of the virtual polygon during tracking, destroying it. Identification performance was higher when the configuration remained intact than when it collapsed (Experiments 1a, 1b, and 2). Moreover, destroying the configuration affected the allocation of dynamic attention: the critical target captured more attention than did the other targets. However, observers were worse at identifying the critical target and were more likely to confuse it with the targets that formed the virtual crossed edge (Experiments 3–5). Experiment 6 further showed that the visual system constructs an overall configuration only by using the targets (and not the distractors); identification performance was not affected by whether the distractor violated the spatial configuration.Conclusions/Significance
In sum, these results suggest that the visual system may integrate targets (but not distractors) into a spatial configuration during multiple identity tracking, which affects the distribution of dynamic attention and the updating of identity-location binding. 相似文献20.