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PubMed1994

Behavioral evidence of trigeminal neuropathic pain following chronic constriction injury to the rat's infraorbital nerve.

Video recordings of free behavior and responses to mechanical facial stimulation were analyzed to assess whether chronic constriction injury (CCI) to the rat's infraorbital nerve (IoN) results in behavioral alterations indicative of neuropathic pain. A unilateral CCI was produced by placing loose chromic gut ligatures around the IoN. After CCI to the IoN, rats exhibited changes in both non-evoked and evoked behavior. Behavioral changes developed in two phases. Early after CCI (postoperative days 1-15), rats showed increased face-grooming activity with face-wash strokes directed to the injured nerve territory, while the responsiveness to stimulation of this area was decreased. Later after CCI (postoperative days 15-130), the prevalence of asymmetric face grooming was reduced but remained significantly increased compared to control rats. The early hyporesponsiveness was abruptly replaced by an extreme hyperresponsiveness: all stimulus intensities applied to the injured nerve territory evoked the "maximal" response (brisk head withdrawal, avoidance behavior plus directed face grooming). This response was never observed in control rats. Concurrently, IoN ligation rats showed a limited increase in the responsiveness to stimulation of the contralateral IoN territory, and around postoperative days 30-40 the responsiveness to stimulation of facial areas outside the IoN territories also increased. The hyperresponsiveness to stimulation of the ligated IoN territory slightly decreased from 60 d postoperative. Throughout the study, IoN ligation rats showed decreased exploratory behavior, displayed more freezing-like behavior, had a slower body weight gain, and a higher defecation rate, compared to control rats. The behavioral alterations observed after CCI to the IoN are indicative of severe sensory disturbances within the territory of the injured nerve: mechanical allodynia develops after a period of relative hypo-/anesthesia during which behavioral signs of recurrent spontaneous, aversive (possibly painful) sensations (paresthesias/dysesthesias) are maximal.

Animals↗

PubMed2005

Musculoskeletal responses of 2-year-old Thoroughbred horses to early training. 5. Kinematic effects.

AIM: To examine the effect of race training on kinematic parameters of the trot in a sample of 2-year-old Thoroughbred fillies. METHODS: Two-year-old Thoroughbred fillies that had been either trained for racing (n=7) or left untrained in small paddocks (n=7) were examined for lameness, and linear and temporal kinematic data were collected from video recordings of each horse trotted in-hand, 5, 9 and 13 weeks after the beginning of training. Horses were graded as: sound (Grade 0), suspected but not obviously lame (Grade 1), or definitely lame at the trot (Grade 2). RESULTS: Mean velocity at the trot did not vary with lameness grade. Compared with horses classified as sound (Grade 0), horses classified as suspected or definitely lame (Grades 1 and 2) had shorter (2.55 (SE 0.02) vs 2.41 (SE 0.02) and 2.44 (SE 0.03) m; p<0.001) and faster (671 (SE 3) vs 645 (SE 1) and 647 (SE 4) msec; p<0.001) strides. None of the linear or temporal parameters measured varied significantly between the successive observation periods. When data from sound horses were pooled, the training group trotted at a higher mean velocity (4.22 (SE 0.08) vs 3.22 (SE 0.06) m/sec; p<0.001) and with a longer stride length (2.79 (SE 0.05) vs 2.18 (SE 0.06) m; p<0.001) than the untrained group. The stride duration was longer (669 (SE 7) vs 662 (SE 9) msec; p=0.01), stance period was shorter (34.1 (SE 0.6) vs 39.3 (SE 0.7) %; p<0.001) and mid-stance was achieved earlier in the stride (12.1 (SE 0.6) vs 13.1 (SE 0.2) %; p=0.001) in the trained than the untrained group. A longer swing phase in the trained group was associated with an increase in retraction time (9.2 (SE 0.2) vs 7.6 (SE 0.3) %; p=0.001). CONCLUSIONS: These data indicate that early race training in young Thoroughbreds was associated with quantifiable changes in linear and temporal kinematic parameters of the trot, which were related to the race-training objective of improving the horse's ability to work at higher velocities. CLINICAL RELEVANCE: Race training resulted in changes in the gait of non-lame horses at the trot, which should be considered during veterinary lameness examinations.

Animals↗

PubMed2007

Medical communication and technology: a video-based process study of the use of decision aids in primary care consultations.

BACKGROUND: Much of the research on decision-making in health care has focused on consultation outcomes. Less is known about the process by which clinicians and patients come to a treatment decision. This study aimed to quantitatively describe the behaviour shown by doctors and patients during primary care consultations when three types of decision aids were used to promote treatment decision-making in a randomised controlled trial. METHODS: A video-based study set in an efficacy trial which compared the use of paper-based guidelines (control) with two forms of computer-based decision aids (implicit and explicit versions of DARTS II). Treatment decision concerned warfarin anti-coagulation to reduce the risk of stroke in older patients with atrial fibrillation. Twenty nine consultations were video-recorded. A ten-minute 'slice' of the consultation was sampled for detailed content analysis using existing interaction analysis protocols for verbal behaviour and ethological techniques for non-verbal behaviour. RESULTS: Median consultation times (quartiles) differed significantly depending on the technology used. Paper-based guidelines took 21 (19-26) minutes to work through compared to 31 (16-41) minutes for the implicit tool; and 44 (39-55) minutes for the explicit tool. In the ten minutes immediately preceding the decision point, GPs dominated the conversation, accounting for 64% (58-66%) of all utterances and this trend was similar across all three arms of the trial. Information-giving was the most frequent activity for both GPs and patients, although GPs did this at twice the rate compared to patients and at higher rates in consultations involving computerised decision aids. GPs' language was highly technically focused and just 7% of their conversation was socio-emotional in content; this was half the socio-emotional content shown by patients (15%). However, frequent head nodding and a close mirroring in the direction of eye-gaze suggested that both parties were active participants in the conversation CONCLUSION: Irrespective of the arm of the trial, both patients' and GPs' behaviour showed that they were reciprocally engaged in these consultations. However, even in consultations aimed at promoting shared decision-making, GPs' were verbally dominant, and they worked primarily as information providers for patients. In addition, computer-based decision aids significantly prolonged the consultations, particularly the later phases. These data suggest that decision aids may not lead to more 'sharing' in treatment decision-making and that, in their current form, they may take too long to negotiate for use in routine primary care.

Aged↗

PubMed2006

Active leukocyte crawling in microvessels assessed by digital time-lapse intravital microscopy.

OBJECTIVE: The ability of active movement is an important feature of leukocytes. Here, we used a hybrid technique that combines intravital microscopy and digital time-lapse video microscopy to investigate the physiology and molecular mechanisms of intravascular leukocyte movement. METHODS: Intravital microscopy of mesenteric venules was performed in male, Wistar rats using digital video recording and time-lapse image compression. The leukocyte movement and extravasation were analyzed after local application of TNF-alpha, after blockade of endothelial (anti-ICAM-1 antibody) and leukocyte (anti-CD18 antibody) adhesion molecules. Additionally, the migratory activity of isolated leukocytes in collagen gel was analyzed and compared with their intravascular locomotion. RESULTS: Adherent leukocytes showed an active intraluminal crawling along the endothelial lining. Most permanent stickers (84 +/- 13%) crawled actively on the intraluminal site of venules. Baseline measurement of leukocyte crawling velocity yielded an average 9.0 +/- 1.8 mum/min that was not significantly different from crawling velocity of extravascular leukocytes (8.9 +/- 4.5 mum/min). The maximum distance of leukocyte crawling observed was 150 microm. The maximum time of crawling was 15 min. Intraluminal crawlers traveled over a mean distance of 35 +/- 17 mum with the average duration of 5.4 +/- 1.4 min. Under unstimulated conditions, almost all crawling leukocytes detached from the endothelium and did not migrate through the vascular wall. TNF-alpha induced a significant increase of leukocyte extravasation. Anti-ICAM-1 and anti-CD18 antibodies significantly reduced leukocyte crawling. The proportion of isolated migrating leukocytes in collagen gel (87% +/- 6%) was not significantly different from the percentage of intravascular crawling leukocytes in vivo. CONCLUSIONS: The method of digital time-lapse intravital microscopy represents an advantageous technology for the investigation of intravascular, transendothelial, and extravascular migration of leukocytes. Using this technology, we showed that leukocyte-endothelial-interactions are an active and dynamic process. This process involves long-time (several minutes) crawling of leukocytes along the endothelium and, finally, detachment from the endothelium. Intravascular leukocyte crawling reflects the migratory potential of circulating leukocytes and strongly depends on the expression of adhesion molecules. For extravasation, an additional pro-inflammatory stimulus is required.

Animals↗

PubMed2005

Joint work and power associated with acceleration and deceleration in tammar wallabies (Macropus eugenii).

Measurements of joint work and power were determined using inverse dynamics analysis based on ground reaction force and high-speed video recordings of tammar wallabies as they decelerated and accelerated while hopping over a force platform on level ground. Measurements were obtained over a range of accelerations ranging from -6 m s(-2) to 8 m s(-2). The goal of our study was to determine which joints are used to modulate mechanical power when tammar wallabies change speed. From these measurements, we also sought to determine which hind limb muscle groups are the most important for producing changes in mechanical work. Because our previous in vivo analyses of wallaby distal muscle function indicated that these muscle-tendon units favor elastic energy savings and perform little work during steady level and incline hopping, we hypothesized that proximal muscle groups operating at the hip and knee joint are most important for the modulation of mechanical work and power. Of the four hind limb joints examined, the ankle joint had the greatest influence on the total limb work, accounting for 89% of the variation observed with changing speed. The hip and metatarsophalageal (MP) joints also contributed to modulating whole limb work, but to a lesser degree than the ankle, accounting for 28% (energy production) and -24% (energy absorption) of the change in whole limb work versus acceleration, respectively. In contrast, the work produced at the knee joint was independent of acceleration. Based on the results of our previous in vivo studies and given that the magnitude of power produced at the ankle exceeds that which these muscles alone could produce, we conclude that the majority of power produced at the ankle joint is likely transferred from the hip and knee joints via proximal bi-articular muscles, operating in tandem with bi-articular ankle extensors, to power changes in hopping speed of tammar wallabies. Additionally, over the observed range of performance, peak joint moments at the ankle (and resulting tendon strains) did not increase significantly with acceleration, indicating that having thin tendons favoring elastic energy storage does not necessarily limit a tammar wallaby's ability to accelerate or decelerate.

Acceleration↗

PubMed1997

Manual dexterity and corticospinal connectivity following unilateral section of the cervical spinal cord in the macaque monkey.

The macaque recovers quite rapidly from the immediate severe flaccid hemiparesis that results from unilateral section of the cervical spinal cord (between C3 and C6) and starts to use the impaired hand to pick up objects within about 30 days following the surgery. Within another 60 days, the monkey is quite dexterous; nonetheless, there is a persisting deficit. We used video recording to study the long-term recovery of manual dexterity following unilateral section of the cervical cord in newborn and juvenile monkeys. A reach-and-retrieve manual task was examined. By using a preset oppositional force, opposition of the pads of the index finger and thumb in the vertical plane was needed to retrieve the desired target object. The corticospinal connectivity of each monkey was also examined by using retrograde or anterograde tracers at the end of the experimental period (Galea and Darian-Smith [1997] J. Comp. Neurol., this issue) and was correlated with the manual performance. Manually retrieving an object depends on the coordination of several control processes acting in parallel, including 1) visually guided components, such as directing the arm toward the object, aligning the digits with the target object by pronating the forearm, and preshaping the index/thumb separation to match with the size and shape of the target, and 2) manipulative components that depend on tactual input and that also include independent movements of the digits and the application of the appropriate oppositional forces. The impairment of manual dexterity that persisted after a cervical section, although it was small, involved these processes and was evident in 1) the less direct trajectory used in reaching, 2) the loss of preshaping of the separated index finger and thumb prior to grasping the target object, and 3) a weakening of the oppositional forces that could be developed between the pads of the index finger and thumb. Although, in the accompanying paper, we did not preclude some regeneration of severed corticospinal connections, we did show that, if any such reconstruction occurred, then it was limited. The remarkable but incomplete recovery of dexterity over a period of 6-12 months, therefore, must be achieved by 1) optimizing the transmission of information from the cortex to the spinal cord by the substantially reduced populations of corticospinal neurons and corticobulbospinal projections and/or 2) the effective use of spinal circuitry in regulating the more stereotyped elements of the manual task.

Age Factors↗

PubMed1992

Kinetics and mechanics of stem gravitropism in Coprinus cinereus.

Using video recordings we have completed the first kinetic analysis of mushroom stem gravitropism. The stem became gravireceptive after completion of meiosis, beginning to bend within 30 minutes of being placed horizontal. Stem bending first occurred in the apical 15% of its length, then the position of the bend moved rapidly towards the base, traversing 40% of stem length in 2.5 h. Meanwhile, the stem elongated by 25%, mostly in its upper half but also in basal regions. If the apex was pinned horizontally the stem base was elevated but overshot the vertical, often curling through more than 300 degrees. When the base was pinned to the horizontal (considered analogous to the normal situation), 90% of the initial bend was compensated as the stem brought its apex accurately upright, rarely overshooting the vertical. The apex had to be free to move for this curvature compensation to occur. Stems transferred to a clinostat after some minutes gravistimulation showed curvature which increased with the length of initial gravistimulation, indicating that continued exposure to the unilateral gravity vector was necessary for continued bending. Such gravistimulated stems which bent on the clinostat subsequently relaxed back towards their original orientation. Reaction kinetics were unaffected by submergence in water, suggesting that mechanical events do not contribute, but submerged stems bent first at the base rather than apex. In air, the gravitropic bend appeared first near the apex and then moved towards the base, suggesting basipetal movement of a signal. In water, the pattern of initial bending was changed (from apex to base) without effect on kinetics. Taken together these results suggest that bending is induced by a diffusing chemical growth factor (whose extracellular propagation is enhanced under water) which emanates from the apical zone of the stem. The apex is also responsible for regulating compensation of the bend so as to bring the tip to the vertical. The nature of this latter stimulus is unknown but it is polarized (the apex must be free to move for the compensation to occur) and it may not require reference to the unilateral gravity vector.

Coprinus↗

PubMed2002

The effect of progressive hypoxia on school structure and dynamics in Atlantic herring Clupea harengus.

The effect of progressive hypoxia on the structure and dynamics of herring (Clupea harengus) schools in laboratory conditions was investigated. The length, width and depth of schools of about 20 individuals were measured from video recordings to test the hypothesis that during hypoxia fish schools change their shape and volume. School shape (calculated as the ratios of length/depth, width/depth and length/width) did not change significantly during hypoxia. School length, width, depth, area and volume were all significantly increased at 20% oxygen saturation. Volume, area and width were more sensitive to hypoxia; volume and width were also increased at 25% and area at 30% oxygen saturation. The degree of position changing (shuffling) of individuals within the school was also analysed. Shuffling in normoxia was observed to occur largely through 'O-turn' manoeuvres, a 360( degrees )turn executed laterally to the school that allowed fishes in the front to move to the back. O-turn frequency during normoxia was 0.69 O-turns fish(-1) min(-1) but significantly decreased with hypoxia to 0.37 O-turns fish(-1) min(-1) at 30% oxygen saturation. Shuffling was also investigated by measuring the persistence time of individual herring in leading positions (i.e. the first half of the school). No significant changes occurred during hypoxia, indicating that the decrease in O-turn frequency does not affect shuffling rate during hypoxia, and that position shuffling in hypoxic conditions is mainly due to overtaking or falling back by individual fishes. School integrity and positional dynamics are the outcome of trade-offs among a number of biotic factors, such as food, predator defence, mating behaviour and various physical factors that may impose certain limits. Among these, our results indicate that oxygen level modulates schooling behaviour. Oxygen alters whole-school parameters at oxygen saturation values that can be encountered by herring in the field, indicating that oxygen availability is an important factor in the trade-offs that determine school volume. An increase in school volume in the wild may increase the oxygen available to each individual. However, shuffling rate is not affected by hypoxia, indicating that the internal dynamics of positioning is the result of the balance of other factors, for example related to the nutritional state of each individual fish as suggested by previous studies.

Acclimatization↗

PubMed1990

Characterization of monocyte adherence to human macrovascular and microvascular endothelial cells.

The interaction of monocytes with cultured large vessel venous and arterial endothelial cells (EC) and with cultured microvascular EC was studied. Analysis of time-lapse microcinematographic video recordings showed that monocytes adhere rapidly to the surface of EC and subsequently remain spherical and fixed to the initial site of adherence. Some monocytes adherent to EC stretch out within 30 to 90 min and migrate over the EC surface or become stretched for about 10 to 30 min and then detach from the EC surface and move rapidly over the EC monolayer. It was shown that the interaction of monocytes with EC is dynamic, that the morphology of monocytes adherent to EC changes constantly, and that stretching of the monocytes over the surface of the EC is not an inevitable and irreversible consequence of binding. A quantitative adherence assay was developed in which both the morphology and the number of monocytes bound to EC were determined. For each type of EC the number of monocytes bound to a single EC was found to be linearly related to the number of monocytes added and was lower for smaller EC. The adherence of monocytes to venous and arterial EC followed a different time course than the adherence to capillary EC and adherence to both types of macrovascular EC was higher than adherence to microvascular EC was higher than adherence to microvascular EC. The percentage of adherent monocytes with a stretched morphology was lower when these cells were adherent to capillary EC than to both types of macrovascular EC and increased upon addition of serum. Adherence of monocytes to venous, arterial, and capillary EC was partially inhibited by mAb directed against the alpha-chain of lymphocyte function-associated Ag-1 or C3bi receptor (with mAb LM2/1, but not with mAb OKM1) and by mAb against the common beta-chain of the three leukocyte adhesion molecules. The degree of inhibition of monocyte adherence to EC by mAb against lymphocyte function-associated Ag-1 alpha and the common beta-chain was dependent on the type of EC and was higher for venous EC (57 to 70% inhibition) than for arterial (40 to 44% inhibition) and capillary (44 to 49% inhibition) EC. Inhibition of monocyte adherence obtained with anti-C3bi receptor-alpha mAb was similar for each EC type. mAb against p150, 95 did not affect adherence. None of the mAb could block binding completely; combinations of the mAb also did not result in increased inhibition of monocyte adherence to EC.

Antibodies, Monoclonal↗

PubMed1990

A microcomputer-based video vector system for clinical gait analysis.

A microcomputer-based video vector system has been developed to display the resultant ground reaction force vector on a television image of the subject in real-time. For each television field the force platform signals are acquired and processed and the resultant force vector superimposed on the video image of the walking subject. The force platform results are stored on disc and the composite video signals recorded on video tape for further analysis. The system is easy to set up and use and the results can be readily interpreted. The external moments produced at the joint centers by the ground reaction forces can be observed visually and, if required, quantification of the external moments can be achieved following data collection. The spatial resolution of the system is 0.342% vertically and 0.156% horizontally. The force vector visualization technique has routine applications in orthotics and prosthetics. It is also a useful technique for the teaching of biomechanics.

Calibration↗

PubMed1988

Data recording and playback on video tape--a multi-channel analog interface for a digital audio processor system.

The design of an analog interface to a digital audio signal processor (DASP)-video cassette recorder (VCR) system is described. The complete system represents a low-cost alternative to both FM instrumentation tape recorders and multi-channel chart recorders. The interface or DASP input-output unit described in this paper enables the recording and playback of up to 12 analog channels with a maximum of 12 bit resolution and a bandwidth of 2 kHz per channel. Internal control and timing in the recording component of the interface is performed using ROMs which can be reprogrammed to suit different analog-to-digital converter hardware. Improvement in the bandwidth specifications is possible by connecting channels in parallel. A parallel 16 bit data output port is provided for direct transfer of the digitized data to a computer.

Electrocardiography↗

PubMed2000

Comparison of erbium:yttrium-aluminum-garnet-laser vitrectomy and mechanical vitrectomy: a clinical study.

OBJECTIVE: To evaluate the clinical usefulness of the erbium:YAG (yttrium-aluminum-garnet) laser for vitrectomy and to compare it with a conventional mechanical vitrectomy system regarding the intraoperative parameters. DESIGN: Prospective, randomized, clinical trial. PARTICIPANTS: Thirty eyes of 30 patients underwent vitrectomy, 15 eyes in each group. METHODS: For mechanical vitrectomy, a commercially available vitrectomy unit was used. The operating parameters, cutting rate (7 Hz = 420 cpm), maximal suction force (300 mmHg), and aspiration flow (20 ml/min), were held constant. A newly developed erbium (Er):YAG laser unit and handpiece was used for laser vitrectomy with predetermined parameters for cutting rate (70 Hz = 4200 cpm), maximal suction force (50 mmHg), and aspiration flow (20 ml/min). Surgery parameters were recorded in real time and the operation was video recorded. The clinical follow-up time was a minimum of 3 months (average, 6.2 months; range, 3-9 months). MAIN OUTCOME MEASUREMENTS: The surgery time was comparable in both groups. During Er:YAG laser vitrectomy, the average suction force was significantly reduced (P< 0.001) compared with that during mechanical vitrectomy. The mean-square variation in suction as a measure to quantify the forces acting on intraocular structures during surgery was significantly smaller in the Er:YAG laser vitrectomy group (P << 0.001). CONCLUSIONS: Erbium:YAG laser vitrectomy may provide a semicontinuous procedure. This technique minimizes periodical intraoperative forces and movements of intraocular structures and may provide, therefore, a safer vitrectomy.

Aged↗

PubMed2006

Relationships of video assessments of touching and mouthing behaviors during outdoor play in urban residential yards to parental perceptions of child behaviors and blood lead levels.

Childrens' touching and mouthing behaviors during outdoor play in urban residential yards were measured using video observations. Descriptions were made of childrens' outdoor residential play environments. Behaviors assessed were used to examine (1) validity of parental responses to questions on childrens' oral behaviors and outdoor play and (2) relationships of mouthing behaviors to blood lead levels (BLLs). Thirty-seven children aged 1-5 years were recruited for 2 h of video recording in their yard and blood lead measurement. Video assessments included hourly rates of hand touches to ground/walking-level surfaces (cement/stone/steel, porch floor/steps, grass, and bare soil) and oral behaviors. Parental questionnaires assessed their child's outdoor activities, behaviors, and home environment. The children were: mean 39 months; 51% male; 89% Hispanic; and 78% Medicaid or uninsured. Twenty-two children had a blood lead measured (mean 6 microg/dl). During taping, all children had access to cement, 92% to grass, 73% to bare soil, and 59% to an open porch. Children had frequent touching and mouthing behaviors observed (median touches/h: touches to surfaces 81; hand-to-mouth area (with and without food) 26; hand-in-mouth 7; and object-in-mouth 17). Blood lead was directly correlated with log-transformed rates of hand-in-mouth (Pearson's correlation, r=0.564, n=22, P=0.006) and object-in-mouth (Pearson's correlation, r=0.482, n=22, P=0.023) behaviors. Parental questionnaire responses did not accurately reflect childrens' observed oral behaviors, play habits, or play environment. These data confirm the direct relationship between hand-to-mouth activities and BLLs and fail to validate parental perceptions of their child's mouthing behaviors or outdoor play environment.

Child Behavior↗

PubMed1983

Anatomic correlation for muscle tension dysphonia.

Dysphonia resulting from increased muscular tension in the larynx and neck is associated with 1) palpably increased phonatory muscle tension in the paralaryngeal and suprahyoid muscles, 2) elevation of the larynx in the neck on increasing vocal pitch, 3) an open posterior glottic chink between the arytenoid cartilages on phonation, and 4) variable degrees of mucosal changes such as vocal nodules or chronic laryngitis. Using six cadaver larynges, the glottic features observed during examination of patients with muscular tension dysphonia (MTD) are reproduced. In each larynx the posterior, lateral, and interarytenoid muscles were dissected free and tension applied in the direction of action in various combinations. Glottic changes were observed, recorded on videotape, and compared to similar clinical video recordings.

Cadaver↗

PubMed1999

A combined electrophysiological and video data acquisition system using a single computer.

Numerous experimental paradigms in behavioral electrophysiology and neuroethology require simultaneous recording of neural signals and behavior. A computer fitted with an analog to digital converter and a frame grabber was configured to perform both tasks. The analog to digital converter collected electrophysiological data while the frame grabber recorded video images. Since spike and image information were present in one computer, arbitrary combinations of electrophysiological and behavioral parameters could be used as the basis of an operant conditioning paradigm. The system was used to record subicular cell firing in rats performing a place search task. The computer monitored the output of the analog to digital converter for supra-threshold events. When one was detected, a block of samples (pre- and post-trigger) was stored in memory. The same computer also scanned every video frame to find the rat, and recorded a image of its behavior. The location of the rat was then quickly calculated. If it satisfied the task conditions, a brain reward pathway (medial forebrain bundle) was stimulated. The recording of neural and image data was monitored in real-time by writing spike waveforms and location data directly to video card RAM.

Algorithms↗

PubMed1998

The exposed ocular surface and its relationship to spontaneous eyeblink rate in elderly caucasians.

The purpose of this study was to assess spontaneous eyeblink activity in the primary eye position, and its relationship to the exposed ocular surface area in elderly individuals without significant ocular surface disease. Spontaneous eyeblink frequency (SEBF) was assessed for a group of Caucasians aged 61 to 81 years, by videography in silence over a 5 min period; inter-blink interval (IBI), the maximum inter-blink interval (mIBI) and the modal eyeblink frequency (mEBF) were derived from video recordings. The ocular surface area was calculated from video-planimetry using different formulae. The average palpebral aperture was 8.3 +/- 2.3 mm (n = 45, +/- S.D.), resulting in an average exposed area of 1.13-2.13 cm2 depending on the formula used; the preferred estimate was 1.25 cm2. A highly significant relationship (P < 0.001, r2 = 0.835) was found between time-averaged palpebral aperture (p) and exposed ocular surface (A = 0.244p-0.763). An average SEBF of 11.9 blinks min-1 was measured (range 0.8-43.6). No correlation (P > 0.35, r2 < or = 0.01) was found between SEBF, IBI, mIBI, or mEBF and the palpebral aperture or the exposed surface area, regardless of the formulae used. The exposed ocular surface area per se does not appear to be an important determinant of spontaneous eyeblink activity in elderly Caucasians.

Aged↗

PubMed1988

Locomotor activity registration by passive infrared detection in saddle back tamarins and tree shrews.

Locomotor activities of tamarins and tree shrews were monitored using a passive infrared detector (PID) and a small hand-held computer as a recording unit. It is a low-cost system, easy to install and to handle without any disturbing effects on the animals investigated. Recording activity is not limited to specific sites in the cage. A temporal resolution of about two seconds for activity detection will meet most experimental requirements. The method was validated by a comparison of PID-recorded signals with simultaneous behavioral observations using a video-recorder. PID is highly specific, detecting only those movements which involve a change in location. The recording system can be adapted to various experimental conditions or other mammalian species.

Animals↗

PubMed2000

Atrioventricular septal defects diagnosed in fetal life: associated cardiac and extra-cardiac abnormalities and outcome.

OBJECTIVES: We sought to establish the outlook for fetuses diagnosed with atrioventricular septal defect (AVSD) prenatally and its relation to additional cardiac, extracardiac and chromosomal abnormalities. BACKGROUND: Prediction of likely outcome of AVSD presenting prenatally is complicated by the wide variation in associated features. METHODS: Computerized records from 14,726 pregnancies referred to a fetal cardiology center were reviewed retrospectively. Pathological reports, postnatal records, follow-up inquiries and review of echocardiographic video recordings supplemented analysis of the records for all those with AVSD. RESULTS: Atrioventricular septal defect was confirmed in 301 fetuses. Eighty-six (39%) of the 218 with known karyotype had trisomy 21, and 21/218 (10%) had other chromosome abnormalities. Right isomerism occurred in 37/301 (12%) fetuses, left isomerism in 62 (20%), mirror image atrial arrangement in 2 (1%), and 200 (67%) had usual arrangement. Atrioventricular septal defect occurred without any other intracardiac abnormality in 155 fetuses (51%). Extracardiac abnormalities and nonkaryotypic syndromes were evident in 40 fetuses (13%, confidence interval [CI] 9.5-17.1%). Uncomplicated cardiac anatomy was significantly associated with the presence of karyotype abnormality (p < 0.0001). Parents opted for termination of pregnancy in 175/298 (58.5%). For the continuing pregnancies, Kaplan-Meier estimates for live birth, survival past the neonatal period and survival to three years were 82% (CI 75.3-88.9%), 55% (CI 46.0%-0/64.3%) and 38% (CI 27.1-48.6%), respectively. Fetal hydrops and earlier year of diagnosis were independent variables with adverse influence on survival. CONCLUSIONS: Despite some improvements in the outlook for AVSD diagnosed prenatally, the overall prognosis remains considerably poorer than that implied from surgical series. The detection of associated cardiac and extracardiac abnormalities is important in order to give the best indication of the likely outcome when counseling parents.

Abnormalities, Multiple↗