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PubMedDate not supplied

Accessibility to the fibronectin synergy site in a 3D matrix regulates engagement of alpha5beta1 versus alphavbeta3 integrin receptors.

Cell adhesion and migration on fibronectin (FN) extracellular matrix are mediated by integrin receptors. Integrins alpha5beta1 and alphavbeta3 require the RGD cell-binding sequence in FN, but alpha5beta1 also requires the nearby synergy site for maximal binding. In this study, we investigated how differences in the numbers of RGD or synergy sites within a three-dimensional (3D) FN-rich matrix influence cell adhesion and migration. CHO cell adhesion, spreading, and migration were reduced on 3D chimeric matrix containing FN lacking RGD (FN(RGD-)). Incorporation of FN with mutation of the synergy site (FN(syn-)), however, resulted in selective usage of integrins. CHO cells expressing alpha5beta1 showed decreased interactions with FN(syn-) chimeric matrix. In contrast, the presence of FN(syn-) had no effect on CHOalphavbeta3 cell migration. Interestingly, CHOalpha5/alphavbeta3 cells expressing both integrins selectively used alpha5beta1 for migration on wild type FN matrix but preferred alphavbeta3 for migration on FN(syn-) chimeric matrix. Thus sequestration or exposure of the FN synergy site within a 3D matrix may represent a novel mechanism for regulating cell functions through differential usage of integrin receptors. [Supplementary materials are available for this article. Go to the publisher's online edition of Cell Communication and Adhesion for the following free supplemental resource: a video recording shows migration of HT1080 cells on 3D matrix. HT1080 cells were allowed to attach to the matrix in serum-free DMEM for 2 h. FBS was then added to the medium to a final concentration of 10% and video recording was started. Images were taken every 5 min for 2 h. The video plays at 6 frames/s.].

Animals↗

PubMed2003

'Understanding and being understood' as a creative caring phenomenon--in care of patients with stroke and aphasia.

Five care providers particularly successful at communicating with patients with communication difficulties were video-recorded together with three patients with aphasia after stroke, during morning care activities. The care providers were then interviewed immediately after the video-recordings, about their experiences of communicating with such patients. The interviews with the care providers were interpreted by means of a phenomenological hermeneutic method. Co-creating was the main theme found. Care providers invite the patient to participate in the creative act of communication. They have a communicative attitude and show interest in the patients' personal desires. The care providers encounter the patient as a presence in a caring communion. In part, care providers communicate by continuously conveying their presence to the patient and even creating availability in a close and open intersubjective relationship. A relaxed and supportive atmosphere facilitates reciprocity between care provider and patient. The communication is not technical or strategic; instead care providers share the patients' experiences in a silent dialogue. This silent dialogue involves sharing the patients' feelings and thus receiving messages from the patient.

Adult↗

PubMed1995

Infrared/video ENG recording of positional nystagmus in subjects with peripheral vestibular disease.

We performed simultaneous infrared/video and electronystagmorgraphy (ENG) recordings of eye movements in 417 patients with disequilibrium. Of that number, 54 patients with the following two criteria participated in this study: verified diagnosis of peripheral vestibular disease and the presence of positional nystagmus recorded by ENG and an infrared/ video recording system. Although horizontal nystagmus was the most common, torsional, vertical and oblique nystagmus were also demonstrated in these patients. The most striking finding was the high incidence of oblique nystagmus closely related to a significant right-left difference of the caloric response in benign positional vertigo.

Adolescent↗

PubMed2000

Topical lidocaine exaggerates laryngomalacia during flexible bronchoscopy.

In 156 infants and children referred for flexible fiberoptic bronchoscopy (FFB) we examined the larynx before and after application of 2% lidocaine solution to see what effect topical anesthesia might have on laryngeal function. All patients received midazolam and nalbuphine intravenously. Using blinded, randomly re-recorded key segments of the original video recordings of bronchoscopy, we used an empirical scoring system (Table 2) to grade signs of laryngomalacia on a scale of 0 to 8 points before and after application of the lidocaine solution. This score was based on the magnitude of collapse of the arytenoids and folding of the epiglottis during inspiration. Topical lidocaine was more likely to result in an increase in signs of laryngomalacia than in a decrease in such signs (p < 0.0001). Younger patients were more likely to have signs of laryngomalacia before topical anesthesia (odds ratio, 1.83). In a group of 10 additional patients, selected for history and physical findings consistent with laryngomalacia, application of a normal saline solution had no effect on the laryngomalacia score, but application of 2% lidocaine solution to the larynx resulted in a significant increase in this score (p < 0.001). Thus, this study has clearly demonstrated that topical anesthesia in infants and children undergoing FFB exaggerates the findings commonly associated with laryngomalacia. Because overestimation of these findings might lead to unnecessary treatment, it is important to examine the larynx and contiguous structures before applying topical anesthesia.

Administration, Topical↗

PubMed1997

A field methodology for ergonomic analysis in occupational manual materials handling.

A methodology is presented for the 'on-site' evaluation of work-related physical activities. In a first session, video recordings were made of six industrial plant workers during their routine occupational tasks. Heart rate (HR) and subjective perception of effort were monitored. The video recordings were then analysed with appropriate software to determine the musculo-skeletal load ('Vision 3000', Promatek, Montreal) and to evaluate energy expenditure ('Energy', University of Michigan). The indirect estimates of energy expenditure were validated in a second session by monitoring the six subjects' oxygen consumption (VO2) during the same activities with a portable telemetric oxygen uptake analyser (Cosmed 'K2', Rome). No statistically significant differences were found between direct measurements of VO2 and the computerised estimates of energy expenditure. Biomechanical parameters obtained in the two sessions did not differ. Therefore, we conclude that the 'Energy' programme and the 'Vision 3000' program provide a fast and reliable profile of job requirements.

Adult↗

PubMed2003

Toric contact lens designs in hyper-oxygen materials.

A high proportion of eyes show significant astigmatism, and therefore toric silicone hydrogel lenses are required to satisfy the demand for continuous wear. Two concerns arise from the inevitable, increased thickness associated with toric designs: reduced oxygen transmissibility and increased rigidity leading to possible mechanical trauma. An improved understanding of the mechanisms governing toric soft-lens orientation and fit will enable the development of thinner designs. Gravity has little effect on prism-ballasted soft lenses within approximately 30 degrees of the base-down position. Some correlations have been noted between lid position and orientation. Measurements from video recordings of toric soft lenses during reorientation indicate that lid-induced rotation takes place during rather than between blinks. However, high-speed video recordings indicate that the influence of the lower lid can override that of the upper lid depending on its position, tightness, and amount of lateral movement. This knowledge gives some pointers toward optimizing toric soft lens designs in hyper-oxygen materials.

Biocompatible Materials↗

PubMed2006

The occurrence of spontaneous functional and nonfunctional orofacial activities in subjects without pain under laboratory conditions: a descriptive study.

AIMS: To assess the occurrence and the modality of spontaneous orofacial behaviors of awake healthy subjects without pain who were unaware of bruxism during wakefulness. METHODS: Sixteen asymptomatic subjects read silently for 30 minutes while polygraphic recordings, including electromyographic (EMG) activity from masticatory and leg muscles, chest respiratory movements, and the movements and sounds of larynx, were made with simultaneous audio-video monitoring. Orofacial behaviors were scored based on the polygraphic and audio-video records. The activity and duration of masseter EMG bursts were calculated for the types of orofacial behaviors. RESULTS: The number of orofacial behaviors varied between subjects; swallowing was most frequently observed. Approximately half of the orofacial behaviors occurred closely with body movements. Of all masseter EMG bursts detected, 55% were associated with functional orofacial behaviors, while 45% were regarded as nonfunctional. More than 80% of these masseter bursts lasted for less than 2 seconds, with an activity less than 20% of maximal voluntary clenching. These values did not differ between the types of associated orofacial behaviors. CONCLUSION: Although the occurrence of spontaneous orofacial motor activity is variable, asymptomatic subjects can exhibit substantial masseter bursts during wakefulness that are not associated with functional orofacial behaviors. The use of physiological and audio-video records permits spontaneous orofacial behaviors to be specifically identified, thereby allowing nonfunctional masseter EMG activity to be differentiated from functional masseter EMG activity.

Adult↗

PubMedDate not supplied

Flow visualization tools for image analysis of capillary networks.

OBJECTIVE: Video recordings of red blood cell (RBC) flow through capillary networks contain a considerable amount of information pertaining to oxygen transport through the microcirculation. Image analysis of these video recordings has been widely used to determine RBC dynamics (velocity, lineal density and supply rate) and oxygenation (Brunner et al., 2000; Ellis et al., 1990, 1992; Ellsworth et al., 1987; Klyscz et al., 1997; Pries 1988). However, not all capillaries in a given field of view are suitable for image analysis. Typically, capillary segments that are relatively straight and in sharp focus, and exhibit flow of individual RBCs that are well separated by plasma gaps, are good candidates for analysis. We have developed several image processing tools to aid in the selection of such capillaries for analysis and to obtain quick overviews of RBC flow through the microcirculation. METHODS: Burgess et al. (Microcirc. 2:75, 1995) and Burkell et al. (Annals Biomed. Eng. 24:1, 1996; J. Vasc. Res. 35:2, 1998) have previously introduced mean and variance images to aid in the selection of capillaries for analysis. We have extended their concept and developed similar two dimensional visualization techniques for studies of RBC flow through capillary networks. RESULTS: Five new methods of processing video data were developed. The minimum image highlights all capillaries containing RBCs in a given field of view. The maximum image identifies capillaries that exhibit high lineal density or stopped flow. The range image represents the difference between the maximum and minimum light intensity values that occur at a given pixel over a given time period, and helps to identify capillary segments that are in good focus and are perfused by RBCs and plasma. The difference image represents the cumulative sum of the square of differences in intensity values between consecutive frames and gives an indication of the frequency of passage of RBCs separated by plasma gaps. The transition image represents the number of times the intensity at a given pixel crosses a predefined threshold and indicates the number of RBCs (or trains of RBCs) that passes a given location during the observation period. CONCLUSIONS: The above flow visualization techniques are valuable tools to aid in the study of image focus, network geometry, RBC flow paths and dynamics, that can then be used in identifying capillaries for subsequent (separate) detailed analysis to provide quantitative information about RBC flow.

Algorithms↗

PubMed2005

Setting standards for the assessment of operative competence.

BACKGROUND: We have previously shown that the operative competence of trainees can be reliably assessed using structured checklists and video recording. These assessments are useful for training (formative assessment). However, a standard setting exercise is required before they can be used for examinations (summative assessment). METHODS: Blinded videos of a saphenofemoral disconnection by an experienced (competent) trainee and an inexperienced trainee (not competent) were scored, using a structured checklist, by 14 consultant vascular surgeons and 14 vascular trainees. The observers were also asked to decide whether the surgeon was competent, borderline or not competent. Thirteen vascular operating room (OR) nurses performed the same exercise. The 'contrasting groups' method was used to compare the cut point between the scores. RESULTS: There was complete separation between the surgeons' scores for the experienced trainee (median 16, range 13-18) and the inexperienced trainee (median 6.5, range 2-12), Chi-square p = 0.0001. This separation was confirmed by the judgements for competent (14-18), borderline (15-7), and not competent (8-2), p = 0.0001. Trainees awarded lower scores than the consultants to both videos, although this difference was not significant. The nurses performed almost as well as the surgeons. CONCLUSIONS: Surgeons can discriminate between the video recordings of a competent and non-competent trainee. Such recordings could form part of a trainee's portfolio and contribute to subsequent examinations (summative assessment). It seems that nurses can also be used to assess the operative competence of surgical trainees.

Arteriovenous Shunt, Surgical↗

PubMed1989

Methods for describing and quantifying +Gz-induced loss of consciousness.

A thorough understanding of +Gz-induced loss of consciousness (G-LOC) is enhanced by defining all psychophysiologic phenomena associated with G-LOC. Defining the mechanism of G-LOC and investigating methods to reduce the resulting incapacitation are facilitated by determining the kinetics of G-LOC induction, incapacitation, and recovery. Permanent video recording of G-LOC episodes is required to accurately define G-LOC events. A method of measuring the time course of G-LOC events using video recording is developed. The resulting calculated and experimental data allow an accurate description of acceleration exposure, resulting incapacitation, and myoclonic convulsions. Although acute physiologic recovery is included in this quantitative framework, longer psychophysiologic recovery remains to be fully evaluated. As such, the techniques developed are established as an initial step in fulfilling the requirement to completely define G-LOC phenomena.

Aerospace Medicine↗

PubMed2000

Blind signal separation from optical imaging recordings with extended spatial decorrelation.

Optical imaging is the video recording of two-dimensional patterns of changes in light reflectance from cortical tissue evoked by stimulation. We derived a method, extended spatial decorrelation (ESD), that uses second-order statistics in space for separating the intrinsic signals into the stimulus related components and the nonspecific variations. The performance of ESD on model data is compared to independent component analysis algorithms using statistics of fourth and higher order. Robustness against sensor noise is scored. When applied to optical images, ESD separates the stimulus specific signal well from biological noise and artifacts.

Algorithms↗

PubMed2002

A new method for describing smokers' consulting behaviours which indicate their motivation to stop smoking: an exploration of validity and reliability.

BACKGROUND: Smokers vary in their readiness to try stopping smoking, but there currently are no objective tools for identifying smokers' consulting behaviours which indicate their level of motivation to try stopping smoking. OBJECTIVE: The aim of this study was to investigate the construct validity and inter-observer reliability of the Smokers' Motivation Code (SMC). METHODS: General practice consultations between 29 different Leicestershire GPs and their patients were video-recorded. In 47 consultations, regular or occasional smokers discussed smoking with their GPs and their consulting behaviour was coded using the SMC. The reliability of three different observers' codings was investigated. Construct validity was also investigated by comparing smokers' consulting behaviours coded using the SMC with measures of motivation to stop smoking recorded on pre-consultation questionnaires. RESULTS: Two pairs of observers achieved good reliability when using the SMC to code smokers' consulting behaviours during a subset of 11 video-recorded consultations. For readiness behaviours (indicating motivation to stop smoking), kappas were 0.82 and 0.65, and for resistance behaviours (indicating little motivation to stop smoking), kappas were 0.74 and 1.0. For the 37 consultations attended by regular smokers, complete pre-consultation questionnaires were obtained. Smokers displaying readiness behaviours were significantly more likely than others to report having tried to stop in the past year, thinking about or trying to stop and to agree that their health would improve if they stopped smoking. Smokers displaying resistant behaviours were significantly less likely to report thinking about stopping/trying to stop smoking. CONCLUSION: We have provided some evidence to support the construct validity and inter-observer reliability of the SMC and have identified some consulting behaviours which might indicate smokers' motivation to stop smoking. Further work is needed to determine whether smokers' consulting behaviour can be used to predict future quit attempts.

Adult↗

PubMedDate not supplied

Fimbria-fornix lesions disrupt the dead reckoning (homing) component of exploratory behavior in mice.

Exploration is the primary way in which rodents gather information about their spatial surroundings. Thus, spatial theories propose that damage to the hippocampus, a structure thought to play a fundamental role in spatial behavior, should disrupt exploration. Exploration in rats is organized. The animals create home bases that are central to exploratory excursions and returns, and hippocampal formation damage alters the organization of exploration by disrupting returns. Mice do not appear to readily establish home bases in novel environments, thus, for this species, it is more difficult to establish the contribution of the hippocampus to exploration. The purpose of the present study was threefold: develop a task in which mice center their exploration from a home base, determine whether the exploratory behavior is organized, and evaluate the role of fimbria-fornix lesions on exploration. Mice were given a novel exploratory task in which their nesting material was placed on a large circular table. Video records of control and fimbria-fornix mice were made in both light and dark (infrared light) conditions. Exploration patterns (outward trips, stops, and homeward trips) were reconstructed from the video records. Control mice centered their activity on their bedding, from which they made circuitous outward trips marked by many stops, and periodic direct returns. The bedding-centered behavior and outward trips of the fimbria-fornix mice were similar to those of the control mice, but significantly fewer direct return trips occurred. The direct homeward trips observed under light and dark conditions were consistent with a dead-reckoning strategy, in which an animal computes its present position and homeward trajectory from self-movement cues generated on the outward trip. Because the fimbria-fornix lesions disrupted the homeward component of exploratory trips, we conclude that the fimbria-fornix may contribute to dead reckoning in mice. The results also show that the home-bedding methodology facilitates the establishment of a home base by mice, thus providing a useful methodology for studies with mice.

Animals↗

PubMed2006

Automated detection of videotaped neonatal seizures of epileptic origin.

PURPOSE: This study aimed at the development of a seizure-detection system by training neural networks with quantitative motion information extracted from short video segments of neonatal seizures of the myoclonic and focal clonic types and random infant movements. METHODS: The motion of the infants' body parts was quantified by temporal motion-strength signals extracted from video segments by motion-segmentation methods based on optical flow computation. The area of each frame occupied by the infants' moving body parts was segmented by clustering the motion parameters obtained by fitting an affine model to the pixel velocities. The motion of the infants' body parts also was quantified by temporal motion-trajectory signals extracted from video recordings by robust motion trackers based on block-motion models. These motion trackers were developed to adjust autonomously to illumination and contrast changes that may occur during the video-frame sequence. Video segments were represented by quantitative features obtained by analyzing motion-strength and motion-trajectory signals in both the time and frequency domains. Seizure recognition was performed by conventional feed-forward neural networks, quantum neural networks, and cosine radial basis function neural networks, which were trained to detect neonatal seizures of the myoclonic and focal clonic types and to distinguish them from random infant movements. RESULTS: The computational tools and procedures developed for automated seizure detection were evaluated on a set of 240 video segments of 54 patients exhibiting myoclonic seizures (80 segments), focal clonic seizures (80 segments), and random infant movements (80 segments). Regardless of the decision scheme used for interpreting the responses of the trained neural networks, all the neural network models exhibited sensitivity and specificity>90%. For one of the decision schemes proposed for interpreting the responses of the trained neural networks, the majority of the trained neural-network models exhibited sensitivity>90% and specificity>95%. In particular, cosine radial basis function neural networks achieved the performance targets of this phase of the project (i.e., sensitivity>95% and specificity>95%). CONCLUSIONS: The best among the motion segmentation and tracking methods developed in this study produced quantitative features that constitute a reliable basis for detecting neonatal seizures. The performance targets of this phase of the project were achieved by combining the quantitative features obtained by analyzing motion-strength signals with those produced by analyzing motion-trajectory signals. The computational procedures and tools developed in this study to perform off-line analysis of short video segments will be used in the next phase of this project, which involves the integration of these procedures and tools into a system that can process and analyze long video recordings of infants monitored for seizures in real time.

Automation↗

PubMed2006

Communication between South Asian patients and GPs: comparative study using the Roter Interactional Analysis System.

BACKGROUND: The UK South Asian population has poorer health outcomes. Little is known about their process of care in general practice, or in particular the process of communication with GPs. AIM: To compare the ways in which white and South Asian patients communicate with white GPs. DESIGN OF STUDY: Observational study of video-recorded consultations using the Roter Interactional Analysis System (RIAS). SETTING: West Yorkshire, UK. METHOD: One hundred and eighty-three consultations with 11 GPs in West Yorkshire, UK were video-recorded and analysed. RESULTS: Main outcome measures were consultation length, verbal domination, 16 individual abridged RIAS categories, and three composite RIAS categories; with comparisons between white patients, South Asian patients fluent in English and South Asian patients nonfluent in English. South Asians fluent in English had the shortest consultations and South Asians non-fluent in English the longest consultations (one-way ANOVA F = 7.173, P = 0.001). There were no significant differences in verbal domination scores between the three groups. White patients had more affective (emotional) consultations than South Asian patients, and played a more active role in their consultations, as did their GPs. GPs spent less time giving information to South Asian patients who were not fluent in English and more time asking questions. GPs spent less time giving information to South Asian patients fluent in English compared with white patients. CONCLUSIONS: These findings were expected between patients fluent and non-fluent in English but do demonstrate their nature. The differences between white patients and South Asian patients fluent in English warrant further explanation. How much of this was due to systematic differences in behaviour by the GPs, or was in response to patients' differing needs and expectations is unknown. These differences may contribute to differences in health outcomes.

Adult↗

PubMed1998

Apnoeic attacks as an isolated manifestation of epileptic seizures in infants.

Apnoea as an isolated manifestation of seizures is well described in neonates but is only occasionally observed in infants. We present data from four infants, with apnoea as the sole manifestation of seizures, documented by polygraphic ictal electroencephalogram (EEGC) and video recording. The four infants, after normal pregnancy and delivery at term, showed the first apnoea at the age of 2-11 months. The interictal EEG was normal. The ictal EEG and video recording showed in all infants a focal rhythmic alpha or theta activity with or without generalization, which lasted 40-120 seconds. The apnoea appeared a few seconds after the beginning of rhythmic activity and the heart rate remained unchanged during the apnoea. At 2 years' follow-up, three children are seizure-free under anti-epileptic therapy with normal psychomotor development in two, and a slight delay in the third infant. The fourth child has partial seizures and is severely retarded.

Apnea↗

PubMed1991

Morphology and mobility of oyster hemocytes: evidence for seasonal variations.

Hemocytes of Crassostrea virginica were video recorded and tracked to determine their locomotive rates and to assign these rates to Wright-stained morphological variants. From 24 oysters examined in January, February, March, and May, 1571 hemocytes were video recorded, identified, and their rate of locomotion (ROL) measured. Granulocytes (three types) and agranulocytes (one lymphoid and three nonlymphoid types) were recognized. Focusing on 15 oysters in March and May, 20,318 hemocytes were counted from duplicate slides to verify the classification and to show that predominant hemocytes vary greatly between samples and among individual oysters, yet population differences can be detected. Measured rates of locomotion indicate that the granulocyte subpopulation moved significantly faster (3.3 microns/min) than the agranulocyte subpopulation (0.7 microns/min) because most (81%) agranulocytes were not mobile. Of the mobile hemocytes, granulocytes were also significantly faster (4.8 microns/min vs. 3.5 microns/min, P less than 0.0001), and basophilic granulocytes (BASOs) were the most active and abundant cell type. Examination of monthly percentages of cells and ROL indicates, however, that granulocyte dominance and ROL are not invariable. Granulocyte percentages of more than 60% in January, February, and March decreased to 32% in May, and BASO dominance was reduced to 15%. Further, percentages of mobile granulocytes decreased from greater than 65% in January, February, and March to 50% in May. ROL for all cells decreased from greater than 2.3 microns/min in these months to 1.0 microns/min in May. The fewer mobile hemocytes tracked in May had significantly (P less than .05) lower average ROL (4.0 microns/min) than those in January and March (4.7 microns/min each). Agranulocytes increased in May due to an increase in nonlymphoid cells.

Animals↗

PubMed1996

Cognitive evaluation of the user interface and vocabulary of an outpatient information system.

This paper describes an innovative approach to the evaluation of the user interface and vocabulary of a medical information system. The use of video recording for collecting usability data is detailed. The technique employed involves the collection of data consisting of transcripts of physicians as they "think aloud" while interacting with the system, along with a video record of the complete user-computer interaction. Using methods of analysis from cognitive science, the study was able to distinguish the source of physician problems in using the system's interface and in interacting with its controlled medical vocabulary. Analysis of the protocols indicated that all subjects encountered several generic problems, the most common ones indicative of a need for greater consistency in the interface design. Based on this evaluation, parts of the user interface have been re-implemented in an ongoing process of iterative system development.

Ambulatory Care Facilities↗