[Photodynamic therapy in pneumology].
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Humans↗
Biomedical subjects
D Geiger
Publications and source records attributed to D Geiger.
Effects of environmental tobacco smoke on objective measures of voice production.
OBJECTIVE: The effects of passive smoking on the voice and laryngeal structures of 20 female passive smokers and 20 age-matched nonsmokers were examined. METHODS: The voice evaluation consisted of acoustic, aerodynamic, and videostroboscopic analyses. RESULTS: Three passive smokers displayed mild edema or erythema. Passive smokers had higher mean flow rates and shorter mean maximum phonation times during sustained vowels at comfortable, low-, and high-pitch levels. However, means were only outside normal limits and significantly different from nonsmokers at high pitch. Variables such as the number of years and hours per day subjects were exposed to environmental tobacco smoke were considered. CONCLUSION: The majority of the variables indicated that vocal fold structure and function were not adversely altered by exposure to passive smoke. Differences between these results and clinical observations are highlighted.
Adult↗
Kinematics of the equine back: flexion-extension movements in sound trotting horses.
This study was undertaken to evaluate the flexion-extension movements of the back in a group of sound trotting horses. Using a 3-D kinematic analysis system, 13 clinically sound horses fitted with 5 skin markers placed on the dorsal midline of their trunk were recorded while trotting on a track in the conditions of the routine lameness examination. These markers were used to calculate 3 back angles (thoracic, thoracolumbar and lumbosacral angle). These back angles were then filtered using Fourier series. To evaluate the repeatability of flexion-extension movements, the intra- and inter-individual variabilities were studied. The angle-time diagrams showed that the equine back extended during the first part of each diagonal stance phase and flexed during the second part of each diagonal stance phase. The ranges of motion were less than 4 degrees for the 3 back angles. The intra- and inter-individual variability values of maximal extension and maximal flexion time points were similar and extremely low. This demonstrates the high repeatability of the temporal pattern of flexion-extension movements of the back. Intra- and inter-individual variabilities of the range of motion showed that the back mobility varies more in-between horses than between trials of the same horse. Compared with electromyographic activities of back muscles reported in the literature, flexion-extension movements described in this study tend to show that, at a slow trot, trunk muscles act mainly to limit flexion-extension movements of the back rather than to induce movements.
Animals↗
Long-term results after 75 anastomoses in the upper extraperitoneal rectum with the biofragmentable anastomosis ring.
BACKGROUND: Anastomoses in the rectum have a higher risk for complications compared with other gastrointestinal regions. Stapling devices and sophisticated developments in surgical suture materials did not lead to a substantial decrease of local complications. The bioabsorbable anastomosis ring (BAR) is a new alternative technique for creating gastrointestinal anastomoses. Accordingly, the aim of this prospective study was to evaluate the postoperative course and long-term results of patients after anterior rectum resection using BAR. METHODS: From 1991 to 1996 75 BAR anastomoses were performed in the upper rectum at the Department of Surgery, University Hospital Würzburg. Thirty-eight patients suffered from malignant, 37 from benign disease. Mean age was 61.4 years with no relevant differences in the gender. Mean follow-up was 31 months (4-63 months). The clinical course was evaluated, a questionnaire completed and/or a 3-monthly reevaluation with endoscopy conducted. Mortality, anastomostic bleeding, leakage and development of anastomotic stenosis were evaluated. RESULTS: Sixty-seven patients could be reexamined. There was no postoperative mortality and no anastomotic bleeding. Six patients (8%) developed an anastomotic leakage, of whom 3 (4%) required reoperation. None of the patients revealed a detectable stenosis in the anastomotic region during follow-up. CONCLUSION: The BAR procedure is a safe and suitable anastomotic technique after anterior rectum resection.
Absorbable Implants↗
[From Murphy's button to the Valtrac Ring. 100 years in search of a paradigm].
In the context of continuous development in the area of anastomotic sutures leading to exceptional results in surgical practice, the biofragmentable anastomosis ring (BAR) described in 1985 by Hardy et al. represents a breakthrough in a 100 years' search of a paradigm. The first anastomotic button created in 1892 by J.B. Murphy was at once accepted as a quick and safe method of intestinal anastomosis. In 1896 Czerny demanded the following: "The task of technology is ... to create buttons with material that is entirely or partly dissolved in the intestinal lumen." Polyglycolic acid--developed in the sixties and now in widespread use for resorbable surgical sutures--was the material to fulfill the requirements already stated in the relevant literature 100 years ago, namely in the form of Hardy's BAR, which represents a redesigned Murphy button exploiting the recent biotechnological developments of this century.
Anastomosis, Surgical↗
[Billroth I anastomosis with biodegradable anastomosis ring in the animal model].
In the present study, the Billroth-I anastomosis with the biofragmentable anastomosis ring was examined in dogs. 24 dogs were randomized into a group of manual suturing (n = 12) and a BAR-group (n = 12). In the group of manual suturing, a distal gastric resection and gastroduodenostomy with sero-submucous suture was performed. In the BAR-group, the distal gastric resection was done with the linear stapler PLC-75, whereby the BAR gastroduodenostomy crossed the stapling line. The dogs were evaluated on p.o. days 4, 14, and 30 and tested for bursting strength and bursting location, appearance of mucosa, hydroxyprolin concentration, and histologic features. There was no functional disorder in the gastrointestinal transit in any animal; in summary with regard to the various parameters, the crossing of BAR and stapling line does not represent any additional risk factor in the Billroth-I anastomosis in dogs.
Anastomosis, Surgical↗
Femoral neuropathy: unusual presentation for recurrent large-bowel cancer.
PURPOSE: The recurrence of colon or rectal cancer may be signaled by serial carcinoembryonic antigen assays, patient symptoms, or radiologic tests such as abdominal and pelvic computed tomographic scans. There are unusual clinical presentations of recurrent disease. METHODS: Retrospectively, six patients with recurrent appendix, colon, or rectal cancer had a femoral neuropathy. Their clinical features and results of reoperative surgery were reviewed. RESULTS: All six patients had thigh weakness and atrophy, and four complained of leg pain. Each of the six patients underwent a reoperation, with a complete cancer resection in four. Pain control was excellent, but only one of the six patients, a patient with appendix cancer, demonstrated prolonged survival. CONCLUSIONS: Leg pain, thigh weakness, and atrophy are compatible with femoral neuropathy and are symptoms and signs compatible with recurrent large-bowel cancer. These findings may alert the clinician to the need for further investigation and treatments.
Adenocarcinoma↗
Overview on compression anastomoses: biofragmentable anastomosis ring multicenter prospective trial of 1666 anastomoses.
This study represents a European prospective clinical multicenter trial and was undertaken to evaluate the applicability of the biofragmentable anastomosis ring (BAR) as a routine anastomotic tool in teaching hospitals. The trial results analyzed consisted of 1666 BAR anastomoses performed in 1360 patients from March 1989 to May 1996 in the upper (1042 anastomoses) and lower (624 anastomoses) gastrointestinal (GI) tract. Only patients selected for elective procedures and having previously undergone orthograde bowel cleansing were entered into the trial. In the upper GI tract six anastomoses (0.58%) developed clinically relevant and radiologically detectable leaks with indications for reoperation. In the lower GI tract 42 (6.73%) anastomoses showed a radiologically detectable leak with clinical manifestations in 28 cases (4.48%). Reoperation was performed in 18 cases (2.80%). The overall leakage rate with clinical relevance was 2.04%. Three gastrojejunostomy episodes of bleeding were observed (0.18%) at the BAR anastomotic site. During the early postoperative course there was no ileus due to obstruction of a BAR anastomosis. Reintroduction of diet after the operation was not delayed. In two centers a follow-up evaluation reported no BAR-related late anastomotic stenoses. There were no intraoperative deaths, but 54 patients died postoperatively. Peritonitis following anastomotic leakage was responsible for postoperative deaths in four cases; three of them were related to BAR anastomoses. In conclusion, the BAR anastomotic procedure is an established, rapid, simple to learn, highly standardized, safe technique with the advantage of no persistent foreign material in the anastomotic region and therefore no induction of stenosis. At present, the application of anastomoses in various segments of the GI tract, from the stomach to the middle third of the rectum, can be recommended.
Adolescent↗
Determining the similarity of deformable shapes.
Determining the similarity of two shapes is a significant task in both machine and human vision systems that must recognize or classify objects. The exact properties of human shape similarity judgements are not well understood yet, and this task is particularly difficult in domains where the shapes are not related by rigid transformation. In this paper we identify a number of possibly desirable properties of a shape similarity method, and determine the extent to which these properties can be captured by approaches that compare local properties of the contours of the shapes, through elastic matching. Special attention is devoted to objects that possess articulations, i.e. articulated parts. Elastic matching evaluates the similarity of two shapes as the sum of local deformations needed to change one shape into another. We show that similarities of part structure can be captured by such an approach, without the explicit computation of part structure. This may be of importance, since although parts appear to play a significant role in visual recognition, it is difficult to stably determine part structure. We also show novel results about how one can evaluate smooth and polyhedral shapes with the same method. Finally, we describe shape similarity effects that cannot be handled by current approaches.
Algorithms↗
Asymmetry in placement of bilateral skin markers on horses and effects of asymmetric skin marker placement on kinematic variables.
OBJECTIVE: To evaluate asymmetry in placement of bilateral skin markers on horses and to determine effect of asymmetric skin marker placement on kinematic variables for trotting horses. ANIMALS: 10 horses for evaluation of asymmetry in marker placement; 1 horse for evaluation of effects on kinematic variables. PROCEDURE: Asymmetry in marker placement was assessed by attaching markers to horses and comparing radiographs of left and right limbs. An experimental model was developed to determine effects on kinematic variables; accuracy of the model was validated experimentally. Using kinematic data from a clinically normal trotting horse as reference data, effects of asymmetric marker placement on vertical displacement-time and joint angle-time diagrams were determined by use of the model. RESULTS: Asymmetry of placement was < 1 cm for markers on the distal portions of the limbs and < 2 cm for markers on the proximal portions. Asymmetric marker placement did not alter general shapes of the vertical displacement-time and joint angle-time curves. In most instances, largest differences in vertical displacement attributable to asymmetric marker placement were equal to or less than magnitude of the asymmetry of placement. Alterations in joint angle-time curves were mainly a result of shifting of the curves on the Y axis. Joint range of motion was only slightly changed by asymmetric marker placement, but maximum flexion and extension angles were greatly altered. CONCLUSIONS AND CLINICAL RELEVANCE: Some kinematic variables can be greatly altered by small differences in skin marker placement. Such effects should be taken into account when evaluating kinematic data for sound and lame horses.
Animals↗
Mechanical correlations derived from segmental histologic study of the equine superficial digital flexor tendon, from foal to adult.
OBJECTIVE: To assess histologic variations of the equine superficial digital flexor tendon (SDFT) according to site and to horse age and activity, and to correlate these data with reported segmental mechanical results. SAMPLE POPULATION: Superficial digital flexor tendons isolated from 42 horses 0.5 hour to 23 years old. PROCEDURE: 7 segments of each SDFT were delimited and submitted for conventional histologic examination. Each segment was examined and graded for fiber undulation, cellularity, number and size of interfascicular connective spaces (ICS), presence or absence of focal and diffuse chondroid metaplasia, and differentiation of the dorsal (DB) and palmar (PB) borders of the tendon. RESULTS: Fiber undulation and cellularity significantly decreased with age. The proximal and middle metacarpal segment fibers were significantly less undulated and their ICS were smaller than those of the other segments, especially in old horses. Focal chondroid metaplasia developed from 5 years onward, mainly in the sesamoidean segments. Diffuse chondroid metaplasia was characteristic of the digital region in horses > 6 years old. The DB of the metacarpodigital region tended to differentiate into fibrocartilage in association with age. The PB was generally differentiated as nonfascicular dense connective tissue. Activity induced a decrease in the number and size of the ICS. CONCLUSIONS: The lesser undulation of the proximal and middle metacarpal segments fibers can be correlated to their mechanical behavior (stress-strain curve) and relative weakness within the SDFT. Focal chondroid metaplasia and fibrocartilage on the DB are normal features, related to the compression stresses undergone by the sesamoidean region of the tendon.
Aging↗
Mechanical properties of pathological equine superficial digital flexor tendons.
The objective of this study was to mechanically characterise superficial digital flexor tendon (SDFT) lesions. Eight pathological SDFTs, isolated from 6 adult horses, were tested in traction until rupture (at 1 mm/s). The stresses and strains simultaneously undergone by each of the 7 segments of a tendon were determined throughout the test, and the modulus of elasticity of each segment was evaluated from the segmental stress-strain curve thus obtained. These mechanical data were compared to those obtained on 10 normal SDFTs. After the test, the tendinous segments were submitted to a histological examination in order to characterise the tissues. Three lesional categories (I to III, of increasing maturity), as well as the normal tendinous tissue, were defined and assessed quantitatively according to their extent in the histological sections. The most recent and severe lesions (categories I and II) were correlated with a large degree of hypertrophy (often above 200%) of the corresponding segments, with a resulting decrease in the stress at tendon rupture, and a slight decrease in the strain at tendon rupture in spite of a low modulus of elasticity (low stiffness). In contrast, the adjacent areas, less or not injured, underwent compensatory strains. This relative overstraining was especially critical with category III tissue, often present in the transitional areas between sound and severely injured segments. Here the modulus of elasticity was low whereas the hypertrophy was only slight. Therefore, the corresponding segments seemed to be the most fragile sites, and those most predisposed to recurring injury, in an injured SDFT.
Analysis of Variance↗
Variability of the limb joint patterns of sound horses at trot.
The reproducibility of gait variables for sound horses is essential for the interpretation of their modifications by locomotor disorders. Therefore, the purpose of this study was to evaluate the variability of the limb joint angle patterns in a population of sound horses while they trotted in the conditions of the routine lameness examination (slow trot, just held by hand, on a track, outdoors). The kinematics of 14 French Saddle horses was recorded using a 3-dimensional (3D) kinematic analysis system. Angle-time diagrams were established in the sagittal plane and their intra- and inter-individual variabilities were evaluated for the whole stride. Horses spontaneously repeated tests at constant speed. The intra- and inter-individual variabilities were low. These values were different from one joint to another and they increased distally. The maximum values were reached by the fetlock and coffin joints. Inter-individual compared to intra-individual variability was 0.9 to 1.9 times greater. There was a high correlation between mean angle-time and mean individual diagrams established for the whole population. It was concluded that it is possible to repeat similar tests with horses trotting in the conditions of the lameness examination. In an homogeneous population, each horse adopts a constant angular pattern that is very close to that of other horses. Since mean angle-time diagrams established on a sound population are highly representative of each mean individual angle pattern, they can be considered as reference data for the further analysis of the pathological gait.
Animals↗
Kinematic analysis of the locomotion symmetry of sound horses at a slow trot.
This study of the locomotion symmetry was undertaken to provide standard symmetry indices of a group of sound horses at the trot. Using a 3D data collection system, the kinematics of the limb joints of 13 clinically nonlame horses were recorded while trotting in the standard conditions of the clinical lameness examination. A kinematic symmetry indice based on an inter-correlation method was defined and applied to the vertical displacement-time and joint angle-time diagrams of the left and right joints of the horses. For each horse, the mean symmetry indice of each joint was calculated using values from 5 trials. For each joint, these means were then averaged. To evaluate the repeatability of the locomotion symmetry, the intra- and inter-individual variabilities of the symmetry indices were studied. The levels of symmetry of the markers of the trunk were generally lower than those of the limbs. Moreover, during the 5 trials these levels of symmetry were strongly variable but their mean values were very similar from one horse to another. In our experimental conditions the trunk presented a higher degree of freedom than the limbs. This high intra-individual variability indicated also that several trials are necessary to quantify the locomotion symmetry of a trotting horse. In the same way, a lower level of symmetry of the hindlimbs, compared to the forelimbs, was proved by their lower values of symmetry indices. As opposed to the supporting role of the forelimbs, the propulsive role of the hindlimbs may explain this feature.
Animals↗
Physical, biological and handling characteristics of surgical suture material: a comparison of four different multifilament absorbable sutures.
OBJECTIVE: Four different braided absorbable surgical materials (Dexon, Dexon II Bicolor, Vicryl and Polysorb) 2/0 USP, which basically share the same indications, were studied in vitro and in vivo with regard to their physical properties as well as tissue compatibility and surgical handling. Analyzing the results the authors tried to determine the most useful suture in surgical practice. METHOD: Physical tests to determine tensile strength, knot-breaking strength and knot security were carried out. Additionally an in vivo model (Wistar rat) was used to compare histocompatibility and loss of function due to hydrolytic resorption. Furthermore, a handling test was carried out by trained surgeons. RESULTS: Polysorb had the highest linear tensile strength but also the fastest loss of function following tissue implantation, whereas Vicryl showed the slowest loss of function. Similar results were obtained with regard to the knot-breaking strength. After pulsatile stressing Dexon II Bicolor and Dexon showed the highest irreversible elongation followed by Vicryl and Polysorb. Polysorb had the best knotting characteristics, scoring highest also in the handling study. CONCLUSIONS: The authors conclude that with Polysorb all features and properties of braided suture material have reached a high level of quality. This suture combines the positive characteristics of monofilament with those of multifilament materials, thus coming closest to being the 'optimal suture'.
Animals↗
[Practical and theoretical aspects of cost-benefit relations in viscerosynthesis].
The necessity of limiting health care costs requires adequate service recording and quality control even in visceral surgery. In this field, the safety of the anastomoses is of greatest importance. Anastomoses at risk are esophageal connections to jejunum or colon and deep rectal anastomoses. At these locations expensive suture devices, such as stapling instruments, can be used in a cost saving aspect, if they help to increase anastomotic safety, time saving and expansion of surgical indication. Manual sutures thus represent the cheapest anastomotic technique as continuous sutures would cost between DM 10.- to 20.- and single stitch sutures between DM 60.- and 100.-. A surgical school should prevalently aim at training manual anastomoses, while special anastomotic techniques should only complete the skill for selected indications. The overall staff expenditure for extended operations amounts around DM 600.- per hour respectively DM 10.- per minute. Time for surgery might be shortened by auxiliary tools as much as to perform an additional operation. However, a circular stapler anastomosis that costs between DM 650.- to 850.- is twice as expensive as manual sutures notwithstanding the double time needed. In the past years, the necessity for a rational use of different anastomotic techniques has shown to be mandatory since, increasingly, financial aspects of health economy require cost benefit calculations in visceral surgery.
Abdomen↗
Three-dimensional kinematic technique for evaluation of horse locomotion in outdoor conditions.
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Animals↗