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PubMed2002

The effect of chin lift, jaw thrust, and continuous positive airway pressure on the size of the glottic opening and on stridor score in anesthetized, spontaneously breathing children.

UNLABELLED: Chin lift and jaw thrust are two common maneuvers used to improve the patency of the upper airway during general anesthesia. We investigated the effect of these maneuvers combined with continuous positive airway pressure (CPAP) on the size of glottic opening and on stridor score. Forty children, aged 2--9 yr, premedicated with midazolam and spontaneously breathing end-tidal 1% halothane and equal parts of nitrous oxide and oxygen, were studied. A flexible fiberoptic bronchoscope was placed via mask and one nostril to the level of the junction of the soft palate and oropharynx. Video recordings and simultaneous stridor scores were obtained during six conditions: 1) chin unsupported, 2) manual chin lift, 3) chin lift and CPAP 10 cm H(2)O, 4) repeat chin unsupported, 5) manual jaw thrust, and 6) jaw thrust and CPAP 10 cm H(2)O. Videos were analyzed to determine the percentage of glottic opening (POGO) score. POGO score increased (P < 0.05) in Conditions 2, 3, 5, and 6. With increasing POGO score there was a decrease in stridor score (P < 0.05). IMPLICATIONS: Chin lift and jaw thrust maneuvers combined with continuous positive airway pressure improve the view of the glottic opening as viewed by flexible nasal laryngoscopy and decrease stridor in anesthetized, spontaneously breathing children.

Anesthesia, General↗

PubMed2004

Facial reanimation by transplantation of a microneurovascular muscle: long-term follow-up.

The two-stage operation for reanimation of long-standing facial paralysis by cross-facial nerve grafting and later free microneurovascular muscle transfer has been the treatment of choice for nearly 25 years. However, the functional outcome may be unpredictable. We therefore need to know more about the factors that influence the final result. We have recorded the long-term results of microneurovascular surgery in facial paralysis, and evaluated which factors influenced the functional outcome. Twenty-seven of 40 patients aged 7 to 65 years (mean 40) operated on at Helsinki University Hospital between 1986 and 2000 were available for interview and video recording. The gracilis, latissimus dorsi, and serratus anterior muscles were used for microneurovascular transfer in 11, 10, and 6 cases, respectively. The outcome of microneurovascular muscle transfer was graded on House's scale 1 to 6. The mean follow-up period was 8.5 years (range 2 to 15). Sixteen patients (59%) displayed only mild or moderate dysfunction (grades 2 to 3) after reconstruction. In 8 patients (30%) dysfunction was graded as moderately severe, and in 3 (11%) as severe. There was a correlation between final functional outcome and the follow-up time after microneurovascular facial reanimation. The longer the follow-up time after muscle transplantation the poorer the functional result (p = 0.003). Twenty-one patients (78%) considered that their quality of life was better or much better after facial reanimation. Patients' satisfaction correlated with a good functional result.

Adolescent↗

PubMed1990

Temporal distributions of red cell supply rate to individual capillaries of resting skeletal muscle, in frog and rat.

Microvascular red cell (RBC) supply in resting skeletal muscle fluctuates with time and varies from capillary to capillary. Our aim was to quantitate this heterogeneity in two species (frog, rat) with very different oxygen requirements. Video recordings were made of RBC flow in capillaries associated with superficial fibers of frog sartorius and rat gracilis muscles, for periods of 2-10 min. RBC supply rate (cell/s) to individual capillaries was computed as the product of RBC 'content' (measured as lineal density, cells/mm, by a video-densitometric method) and RBC velocity (mm/s, measured by a spatial correlation technique). The videotapes were analyzed at rates of 6 to 15 samples per second. Regression analysis of the mean data showed little or no correlation between RBC content and RBC velocity (r2: frog 0.095, rat 0.002), both parameters contributing equally to variations in RBC supply rate. Temporal distributions of the three supply parameters demonstrate (1) the wide range of values present within each capillary, and (2) the symmetry of the distributions at high mean values versus a pronounced skewness as mean values approached zero. The wide range of mean values of each parameter, found in both species, suggests considerable 'spatial' heterogeneity of RBC supply among capillaries in resting muscle. Temporal heterogeneity of RBC supply rate to individual capillaries increased markedly as either velocity or content (or both) approached zero (overall mean coefficient of variation: frog, 62%; rat, 100%). Both species show remarkably similar rates of convective transport of RBCs per capillary in resting muscle (e.g. mean supply rates 3.2 and 6.2 RBCs/s in frog and rat, respectively).

Animals↗

PubMedDate not supplied

Determination of red blood cell velocity by video shuttering and image analysis.

A novel modification of conventional video imaging techniques has been developed to determine the velocity of red blood cells (RBCs), which offers compatibility with existing video-based methods for determining blood oxygenation and hemoglobin concentration. Traditional frame-by-frame analysis of video recordings limits the maximum velocity that can be measured for individual cells in vivo to about 2 mm/s. We have extended this range to about 20 mm/s, by electronic shuttering of an intensified charge-coupled device camera to produce multiple images of a single RBC in the same video frame. RBCs were labeled with fluorescein isothiocyanate and the labeled cells (FRBCs) were used as probes to determine RBC velocities in microvessels of the hamster retractor muscle. Velocity was computed as the product of the distance between centroids of two consecutive image positions of a FRBC and the shuttering frequency of the camera intensifier. In vitro calibrations of the system using FRBC and Sephadex beads coated onto a rotating disk yielded an average coefficient of variation of about 6%. Flow conservation studies at bifurcations indicated that the maximum diameter of microvessels below which all the FRBCs in the lumen could be detected was 50 microm. The technique was used to estimate mean-FRBC velocity distributions in vessels with diameters ranging from 8 to 50 microm. The mean-FRBC velocity profiles were found to be blunter than would be expected for Poiseuille flow. Single FRBCs tracked along an unbranched arteriole exhibited significant temporal variations in velocity.

Animals↗

PubMed1991

Labeling of developing vascular endothelium after injections of rhodamine-dextran into blastomeres of Xenopus laevis.

The goal of this work has been to label endothelial cells with fluorescent marker and to record their behavior during angiogenesis in vivo. Single blastomeres in 16-128-cell-stage embryos of pigment-deficient Xenopus laevis were injected intracellularly with 5% tetramethyl-rhodamine dextran. Subsequently, the embryos and tadpoles were examined with an epifluorescence microscope, a silicon-intensified target (SIT) camera, and video recordings. Clones that would include endothelium could be selected as early as stages 33-36 on the basis of heavy labeling in the ventral mesodermal core of the tail. Strands of fluorescent cells and early vessels appeared in the tail at stages 39-41. Subsequently, groups of endothelial cells were followed in case histories in the tail and in the aortic arches and gills of tadpoles. Two main results were that the patterns of fluorescent endothelial cells were stable in established arteries, veins, and capillaries for at least 2-12 days, and that labeled endothelial cells migrated distally in elongating sprouts. In addition, it was inferred that endothelium was derived from multiple blastomeres, probably in the ventral vegetal regions. Only small fractions of total endothelium were labeled from any single blastomere. None of the early blastomeres produced exclusive clones of vascular endothelium; other labeled cell types in various clones included muscle fibers, lymphatics, mesodermal stellate cells, blood cells, gut, proctodeum, and some epidermis, in addition to endothelial cells. The method of intracellular marking of blastomeres is recognized as a direct approach for charting lineage and fate tables in embryos of Xenopus and other species. The present study extends the period of observation in vivo for up to 2 weeks in the growing tadpole and focuses on endothelial cells during angiogenesis. Even though fluorescent dextran was apparently packaged in vesicles and metabolized, individual cells and small groups could be identified and followed with time. This method provides excellent opportunities for addressing problems in vascular development in the living animal.

Animals↗

PubMed1996

Transient effects of microgravity on early embryos of Xenopus laevis.

In order to study the role of gravity on the early development of the clawed toad Xenopus laevis, we performed an experiment on the Maser-6 sounding rocket launched from Kiruna (Sweden) on 4 Nov 1993. The aim was to find out whether a short period of microgravity during fertilization and the first few minutes of development does indeed result in abnormal axis formation as was suggested by a pilot experiment on the Maser 3 in 1989. On the Maser 6 we used two new technical additions in the Fokker CIS unit, viz. a 1-g control centrifuge and a video recording unit which both worked successfully. The 1-g control centrifuge was used to discriminate between the influences of flight perturbations and microgravity. After fertilization shortly before launch, one of the first indications of successful egg activation, the cortical contraction, was registered in microgravity and on earth. Analysis of the video tapes revealed that the cortical contraction in microgravity starts earlier than at 1 g on earth. After recovery of the eggs fertilized in microgravity and culture of the embryos on earth, the morphology of the blastocoel has some consistent differences from blastulae from eggs fertilized in the 1-g centrifuge of the rocket. However from the gastrula stage onward, the microgravity embryos apparently recover and resume normal development: the XBra gene is normally expressed, and histological examination shows normal axis formation.

Animals↗

PubMed1999

Control of abdominal extension in the freely moving intact crayfish cherax destructor. I. Activity Of the tonic stretch receptor

Electrical recordings were made from the sensory neurone of the tonic muscle receptor organ in the abdomen of the intact, freely behaving crayfish Cherax destructor. Slow extensions of the abdomen were evoked by lowering a platform from beneath the suspended crayfish, and the movements and tonic sensory neurone activity were video-recorded simultaneously. The recordings showed that the tonic sensory neurone was active when the abdomen was fully flexed prior to the extension. When the extension began, however, the sensory neurone ceased firing shortly after movement was detected, irrespective of the load applied to the abdomen. When the abdomen was physically blocked from extending fully, the sensory neurone did not fire. The tonic muscle receptor organ is considered to be the length-detecting sensor for a load-compensating servo-loop, but the results demonstrate that its activity pattern during extensions evoked by a platform-drop in C. destructor are not consistent with that role.

Journal Article↗

PubMed2000

High-speed digital microscopy.

High-speed imaging is an ideal technique to accurately resolve the temporal and spatial characteristics of rapid events at either the molecular or cellular level. In this article, the digital imaging techniques used to simultaneously acquire transillumination phase-contrast images, at 240 images s(-1) (high-speed), to characterize ciliary beat frequency, and fluorescence images, at 30 images s(-1) (fast), to measure intracellular calcium concentration ([Ca2+]i), are described. With this technique, a precise correlation between the changes in ciliary beat frequency with changes in [Ca2+]i can be made. Simultaneous imaging is achieved by using different wavelengths of light to form the phase-contrast and fluorescent images and selectively directing these light wavelengths to different cameras with dichroic mirrors and bandpass filters. High-speed images compatible with standard video recording equipment are obtained by prematurely resetting the raster scan of a CCD camera with additional vertical synchronization pulses. The fast [Ca2+]i images are determined using the ratiometric dye fura-2 and a recording technique that monitors rapid changes in fluorescence at a single wavelength and uses intermittent reference images for calibration.

Image Processing, Computer-Assisted↗

PubMed1991

How we teach the doctor-patient relationship.

Since the reform of the Italian medical degree in 1988, fourth-year students now study the dynamics of the doctor-patient relationship as part of the compulsory 'methodology of the clinical, therapeutic, prevention and rehabilitation approach' course. This work illustrates a pilot scheme carried out at the Milan University Medical School and begun shortly before the reform of the Italian medical degree. In dealing with the teaching of the doctor-patient relationship, the authors look into a relational-psychological perspective which is supported by notions and instruments intrinsic to medical pedagogy. The work is handled along three main lines: (a) presentation of a relational teaching model and definition of teaching objectives; (b) presentation of the methods and techniques used (role-playing, videotape recordings, video simulation and group work); and (c) discussion on the evaluation criteria.

Curriculum↗

PubMedDate not supplied

Ambulatory monitoring of physical activity in working situations, a validation study.

How to assess a patient's functional physical mobility in non-laboratory situations has been a problem for the medical services for a long time. A measurement system using accelerometry (DynaPort ADL Monitor) has been developed to cope with this problem. It is a lightweight recorder that is worn around the waist. It uses accelerometry to ambulatory monitor the Activities of Daily Living (ADL). In this study the reliability of the monitor in two working situations of one patient has been assessed: maintenance mechanic and messenger in a city hall. All actions were simultaneously videotaped. The video recording was interpreted by an observer. Independent of this, the acceleration signals were translated by the monitor software into one of the basic postures or movements: locomotion, standing, sitting, lying and playing. Every second the monitor and observer interpretation were compared and maximal and minimal validity percentages were calculated for all classes and for the total measurement. The overall (minimal) validity was found to be higher than 86%. The maximal validity was 93% of the total measurement in the patient's job as a maintenance mechanic. Considering the simple instrumentation of the ADL monitor this validity is considered good.

Activities of Daily Living↗

PubMed2004

[Design of a prototype operating seat with SESAM (Ergonomic System of Mobile Forearm Rests) mobile armrests designed to optimize the surgeon's ergonomy during pelvic laparoscopy].

INTRODUCTION: Pelvic laparoscopic surgery offers multiple advantages for patients, but requires uncomfortable, non-ergonomic positions for the surgeon. Only a remote operator (Robot "slave" reproducing the surgeon's movements performed on a "master" console situated away from the patient), like Da-Vinci or Zeus (Intuitive Surgical) can improve the laparoscopic surgeon's working conditions. The objective of this study, based on an ergonomic analysis and recording of a laparoscopic surgeon's movements, was to define the specifications for the manufacture of an operating seat with armrests, based on the surgeon's position using a remote operator. MATERIAL AND METHODS: Movements of the centre of pressure and upper limbs of 12 urologists and gynaecologists with various levels of experience, were recorded using a force platform and a SAGA 3 RT movement analysis system (Biogesta), during 4 exercises performed on a pelvi-trainer, with the surgeon positioned to the left (introduction of a needle, unravelling of a cord, dissection, suture). Ergonomic analysis of the laparoscopic surgeon's movements was based on video recordings of a surgeon under real operating conditions. The specifications were defined from all of these data. RESULTS AND DISCUSSION: The small amplitude of movements of the surgeon 's centre of pressure (< 45 cm2) confirmed that surgeons can be seated during laparoscopy. Recordings of the upper defined the elbow working zones and the need for 3D mobile armrests. Ergonomic analysis of posture defined the characteristics of the prototype. On the basis of these specifications, a prototype operating seat was developed. This prototype now needs to be validated or invalidated clinically.

Arm↗

PubMedDate not supplied

Evaluation of video tape and a simulator for instruction of basic surgical skills.

Twenty first-year veterinary students with no prior participatory experience in surgery were randomly paired and assigned into two study groups. Ten students (group V) viewed a hemostatic technique video tape until they thought they could competently perform and assist in performing a hand-tied ligature on a blood vessel in a live animal. Ten students (group VS) wer also given a simulator for technique practice. Paired students were video recorded and blindly evaluated on their ability to perform and assist proper ligation of a bleeding vessel. Inexpensive hemostasis models were very helpful for teaching students essential surgeon and assistant skills involved in hand-tied ligature placement. Students who practiced with simulators performed significantly better as surgeon and assistant, and in total psychomotor skill evaluation, then students watching the video only. Students using simulators performed ligation with significantly more accuracy and tended to be more expeditious at this task. Further training is needed for students to acquire skills necessary for efficient bleeding vessel exposure and isolation.

Animals↗

PubMed1993

The St. Hans Rating Scale for extrapyramidal syndromes: reliability and validity.

The St. Hans Rating Scale (SHRS) is a multidimensional rating scale for the evaluation of neuroleptic-induced hyperkinesia, parkinsonism, akathisia and dystonia. This scale and the Abnormal Involuntary Movement Scale (AIMS) were tested by 7 raters (2 experienced, 2 less experienced and 3 totally inexperienced) in 30 psychiatric patients with tardive dyskinesia (TD). The test was performed 3 times in the same patients: 1) live evaluation during a video recording, 2) evaluation 2 weeks later from the videotape, and 3) evaluation after another 2 weeks from the same videotape. The intrarater reliability was high in the experienced group (0.91-0.96 for SHRS hyperkinesia scale, 0.80-0.84 for AIMS, and 0.82-0.97 for SHRS total parkinsonism). No significant changes occurred from live to video evaluation. The interrater reliability coefficient for the experienced group was also high: 0.89-0.95 for the SHRS hyperkinesia scale, 0.76-0.85 for the AIMS scale and 0.95-0.98 for the SHRS parkinsonism scale. The less experienced and the inexperienced raters had coefficients for intra- and interrater reliability that were 0.10 and 0.20 lower, respectively. The SHRS parkinsonism scale had a high construct validity, as determined by the homogeneity coefficients of Cronbach (0.82) and Loevinger (0.43). The corresponding coefficients for the hyperkinesia scales were low, in agreement with the individual distribution of TD (only about 50% present extremity dyskinesia and less than 25% facial, head and trunk dyskinesia, independent of the severity of the syndrome). Finally, convergent validity was found between the SHRS hyperkinesia scale and AIMS and divergent validity between all of the other scales.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed2003

Molluscs in biological monitoring of water quality.

Molluscs living in Lake Balaton accumulate persistent toxic substances, namely heavy metals, to a greater extent, than other organisms, and can serve as excellent passive biomonitors. Especially gills are good accumulators. Regular sampling showed that the level of Cd and Hg concentrations increased, while Pb contamination decreased during the past 20 years in mussels, corresponding probably to changes in pollution of the Lake. In functional, active monitoring various behavioral patterns of molluscs were employed. In mussels the periodicity of activity and rest (pumping activity vs. valve closure) is a sensitive indicator of unfavorable conditions and so of toxic substances. Low concentrations of inorganic and organic toxicants (heavy metals, PCBs, PAH compounds) cause reduction of the active and increase of the rest periods in a concentration dependent manner in a few hours. A second, suitable test for evaluating toxicity of chemicals is the measurement of the water flow through the exhalant siphon. Under the effect of toxicants the siphon activity, both the strength and duration of water flow changes characteristically within a few minutes. For both behavioral tests special techniques have been developed suitable for long duration recording, supported by mechano-electrical transduction and computerized data evaluation. In case of the pond snail (Lymnaea stagnalis L.) the behavior (positive/negative geotaxis and orientation) is disturbed in the presence of the above mentioned toxic chemicals. The execution and evaluation of the changes in the movement of the snail is based on video-recording and measurement of the direction and distance the animal performs in uncontaminated water and in the presence of the pollutants during the same period of time (0.5-4 h).

Animals↗

PubMed1995

Evaluation of changes in skeletal muscle blood flow in the dog with contrast ultrasonography.

Intraoperative methods to assess skeletal muscle blood flow or muscle-flap perfusion during vascular reconstructive surgery are limited. At present, techniques enable only anatomic identification of the degree of patency of large vessels. We report here the first use of ultrasonography to assess dynamic changes in skeletal muscle perfusion. Baseline blood flow in the adductor muscle group of the hindlimbs of seven dogs was measured with an electromagnetic flow probe and with contrast ultrasound using the contrast agent Albunex. Blood flow was manipulated in each dog pharmacologically with random administration of intraarterial injections of Neo-Synephrine and papaverine. After each change in blood flow detected by electromagnetic flow probe, flow also was assessed qualitatively by four independent observers who graded video-recorded contrast enhancement in the muscle group on a 0 to 4 scale. Videodensitometry also was used to generate time versus intensity curves in the adductor muscle region of interest. Peak pixel intensity was determined during each flow condition. A total of 21 flow measurements were made with each assessment scheme (electromagnetic flow probe, video enhancement, videodensitometry) for each condition (7 control, 7 papaverine, 7 Neo-Synephrine). Changes in blood flow assessed by video enhancement scores and changes in peak pixel intensity correlated with changes measured by electromagnetic flow probe (r = 0.84 and 0.66, respectively). We conclude that contrast ultrasound may be used to detect changes in skeletal muscle perfusion intraoperatively. Measures of muscle perfused by visual inspection of contrast enhancement and videodensitometric data were in agreement with direct measurements of changes in skeletal muscle blood flow.

Animals↗

PubMed2001

Analysis of the dysfunctional eustachian tube by video endoscopy.

OBJECTIVE: Human eustachian tubes with known pathologic conditions of the ear were inspected endoscopically, and video recordings were made for slow-motion analysis of the pathophysiologic changes. SETTING: Ambulatory office in a tertiary referral center. SUBJECTS: Forty-four adults with 64 ears having pathologic conditions. INTERVENTIONS: Transnasal endoscopic examination of the nasopharyngeal opening of the eustachian tube during rest, swallowing, and yawning to study the dilatory movements of the eustachian tube. MAIN OUTCOME MEASURES: Slow-motion video analysis of the dilatory movements of the eustachian tube. RESULTS: Sixty-four ears and eustachian tubes with pathologic changes were studied. Tubal function was graded on (1) the extent of lateral excursion and progression of dilatory wave as estimates of tensor veli palatini and dilator tube muscle function, reduced function being observed in 43 tubes; (2) the degree of mucosal disease, which was significant in 48 tubes; (3) obstructive mucosal changes, which were present in 15 tubes; (4) ease and frequency of tubal dilation with maneuvers-26 tubes opened moderately, 21 opened minimally, and 11 were unable to open; and (5) patulous tubes-all 6 clinically patulous tubes showed concavities in the superior third of the tube, which is convex in normal subjects. All tubes with active pathologic conditions of the ear (otitis media with effusion, tympanic membrane retraction, draining ear, cholesteatoma) had significant abnormalities. A correlation could not be made between the severity of middle ear disease and the severity of observed eustachian tube dysfunction. CONCLUSIONS: Slow-motion endoscopic video analysis is a potentially useful technique in classifying types of pathologic changes in the eustachian tube. Additional studies of dysfunctional tubes are needed to predict outcomes in operative ear cases and to design intratubal therapy for chronically dysfunctional tubes.

Adult↗

PubMed2000

Dizziness in discus throwers is related to motion sickness generated while spinning.

While both discus and hammer throwing involve rotating movements resulting in the throw of an object, discus throwers sometimes report dizziness, a condition never experienced by hammer throwers. We investigated whether this susceptibility was related to the sensitivity of the thrower or to the type of throwing achieved. For the latter, we compared the determining features of gesture, gaze stabilization and projectile trajectory in both sports. A total of 22 high-level sportsmen in these 2 disciplines, half of them practising both sports, were interviewed. Slow motion video recordings of discus and hammer throwing were examined to determine the visual referential, head movements and plantar surface support area involved at each stage of the motions. Discomfort was reported by 59% of the sportsmen while throwing discus, but by none while throwing hammer. Because several individuals practised both sports, these results exclude the hypothesis of individual susceptibility to dizziness. Video analysis evidenced that during hammer throwing, visual bearings can be used more easily than during discus throwing. Moreover, there is a loss of plantar afferents and generation of head movements liable to induce motion sickness, such as Coriolis acceleration. In conclusion, although hammer and discus-throwing present numerous similarities, we demonstrate here that crucial differences in the specific execution of each sport are responsible for the dizziness experienced by discus throwers.

Adult↗

PubMed1996

Sensory aspects of host location in mosquitoes.

Visual, thermal and olfactory stimuli all contribute to blood meal host location in mosquitoes but olfaction is probably the dominant sensory modality used for this purpose. Much attention has been devoted to the L-lactic acid receptor because it is well characterized and because its sensitivity is a major determinant of host responsiveness in the anautogenous species Aedes aegypti. Studies employing statistical analysis of close to 500 single unit recordings and the scanning electron microscope have demonstrate that L-lactic acid-excited neurons are associated with the shortest sensilla basiconica (grooved pegs) in Ae. aegypti, Culex pipiens, Aedes atropalpus and Aedes epactius. L-Lactic acid-inhibited neurons are found in either short or long grooved pegs, depending on mosquito species. Video recording analysis, a vertical dual-chamber olfactometer and a horizontal dual-port wind tunnel olfactometer have been used to study host location behaviour and nutritional preferences in the obligately autogenous Ae. atropalpus, the facultatively autogenous Aedes bahamensis and the adult diapausing species Cx. pipiens. These behavioural studies, in conjunction with electrophysiological analysis, illustrate the ways in which the interactions between reproductive condition, developmental stage and L-lactic acid receptor sensitivity determine the nutritional choice made between blood and sugar by mosquitoes and demonstrate the role that olfactory sensitivity plays in this process.

Animals↗