[Influence of age on optical aberrations of the human eye]. / Einfluss des Alters auf die optischen Aberrationen des menschlichen Auges.

BACKGROUND: Currently the influence of age on corneal and ocular aberrations is still insufficiently known. The aim of this clinical study was to compare age-related aberrations of human eyes. METHODS: In a prospective study 98 eyes of 49 healthy patients ranging from 17 to 65 years of age (38.6+/-10.0 years) were consecutively examined. The best corrected visual acuity ranged from 0.8 to 1.6; 48 eyes were emmetropic (SE+/-0.5 D), 42 eyes myopic (SE <-0.5 to -6.75 D), and 8 eyes hyperopic (SE >+0.5 to +3.88 D). The corneal aberrations were derived from corneal topography (Keratron Scout, Optikon). The measurement of ocular aberrations was performed with a Tscherning wavefront aberrometer (ORK, Schwind). The aberrations of the Zernike coefficients and RMS values (1st to 4th order) were determined. RESULTS: The mean corneal and ocular Zernike coefficients of higher order were smaller than 0.2 microm. There was an evident decrease of wavefront aberrations with increasing order. Higher order corneal aberrations were larger than the corresponding ocular aberrations. With increasing age higher optical errors increased in complexity, and the correlation of corneal and ocular aberrations decreased with significant differences. Although the corneal ocular RMS value of the 3rd and 4th order correlated in the younger group (r=0.51, p=0.0001), there was no correlation in the older group (r=-0.48, p=0.832). The influence of age caused a significant increase of ocular aberrations of the 3rd and 4th order, in particular a tenfold extension of coma (C07) (p=0.002), a twofold extension of spherical aberration (C12) (p=0.0001), and an increase of the 3rd and 4th order RMS values (p=0.001). CONCLUSIONS: Increased age induced an increase in optical aberrations of the eye, which demonstrates the influence of the lens on ocular aberrations. The combination of corneal and ocular diagnostic methods is recommendable for a better understanding of visual performance.

["Shrinkage of cruciate ligaments"--a biomechanical study. Shrinkage of elongated cruciate ligaments using an application of radiofrequency energy]. / 'Kreuzbandschrumpfung"--eine biomechanische Studie. Schrumpfung von elongierten Kreuzbändern unter Anwendung von Radiofrequenzenergie.

The aim of this study was to evaluate structural properties of native and elongated bovine anterior cruciate ligaments after the application of bipolar radiofrequency. Using a material testing machine typical load-elongation curves were used to determine the initial strength of untreated (group 1, n = 20) and elongated cruciate ligaments (group 2, n = 20) after treatment with bipolar radiofrequency (ArthroCare). After the application of a cyclic loading protocol (1000 x 400 N) elongation, yield load, maximal load, and stiffness were determined. Native ligaments served as a control group (group 3, n = 20). In both groups 4 mm reduction in length was caused by the application of radiofrequency. Elongation was significantly higher; yield load, maximal load, and stiffness of cruciate ligaments treated with radiofrequency (groups 1 and 2) were significantly reduced after the application of a cyclic loading protocol in comparison to the control group (p < 0.05). Group 2 ligaments showed the lowest values. The application of radiofrequency weakens the biomechanical properties of native and elongated cruciate ligaments significantly. When radiofrequency energy is used to shrink elongated cruciate ligaments, a nonaggressive rehabilitation protocol should be applied.

One-way distribution system for water for injection: process management, microbiological quality control, and meeting regulatory requirements.

The specifications for pharmaceutical water, the qualification and validation of water preparation facilities, strategies to prevent contamination by water-borne bacteria and lastly, the monitoring of microbiological purity are the topics of frequent seminars on Pharma Water Total Quality Management. The same subdivisions are used in the following paper on the process management and microbiological control of a one-way distribution system for Water for Injection. Since 1990, such a system has been in use in the production department of Pharma Hameln GmbH, a contract manufacturer of parenterals. Using this system as an example, the twin needs for flawless microbiological process control and for suitable measures to monitor water quality are discussed, which, together with extensive documentation of the qualification of the production and distribution system, ultimately led to acceptance of the system by regulatory authorities.

Botulinum toxin type A and short-term electrical stimulation in the treatment of upper limb flexor spasticity after stroke: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: To investigate whether the combined approach of botulinum toxin type A (BtxA) and electrical stimulation was more effective than the toxin alone in the treatment of chronic upper limb spasticity after stroke. DESIGN: Randomized, placebo-controlled study with four treatment groups: 1000 units BtxA (Dysport) + electrical stimulation (A), 1000 units BtxA (B), placebo + electrical stimulation (C) and placebo (D). SETTING: A neurological rehabilitation clinic. SUBJECTS: Twenty-four stroke patients with chronic upper limb spasticity after stroke, six patients in each treatment group. INTERVENTIONS: Intramuscular injection of either toxin or placebo into six upper imb flexor muscles. In group A and C additional electrical stimulation of the injected muscles with surface electrodes, three times half an hour each day for three days. MAIN OUTCOME MEASURES: Muscle tone rated with the modified Ashworth score, limb position at rest and difficulties encountered during three upper limb motor tasks assessed before and 2, 6 and 12 weeks after injection. RESULTS: Most improvements were observed in patients of group A. Cleaning the palm (p = 0.004) differed across groups. Pairwise comparison for this target variable showed that group A differed from group B and D (p <0.01), but not from C. Indicative across-group differences were obtained for elbow spasticity reduction (p = 0.011), and improvement of putting the arm through a sleeve (p = 0.020). CONCLUSIONS: The placebo-controlled trial favours the concept that electrical stimulation enhances the effectiveness of BtxA in the treatment of chronic upper limb flexor spasticity after stroke.

Sit-to-stand manoeuvre in hemiparetic patients before and after a 4-week rehabilitation programme.

The objective of the study was to document the sit-to-stand of 35 moderately affected hemiparetic patients before and after a 4-week inpatient rehabilitation programme and to investigate the influence of the side of hemiparesis and impaired proprioception on its outcome. The therapists trained the patients to distribute equal weight on both legs and to avoid lateral compensatory tilt of the trunk. The body weight distribution and the displacement of the centre of mass in the frontal plane were studied by assessment of triaxial ground reaction forces. Symmetrical weight acceptance and minimal lateral sway were not reached during the 4-week rehabilitation, with the exception of the patients with a left hemiparesis (n = 19) and no proprioceptive deficit (n = 18).

Immediate effects of therapeutic facilitation on the gait of hemiparetic patients as compared with walking with and without a cane.

OBJECTIVES: Although the neurodevelopmental technique (Bobath) is the most widely used approach in the gait rehabilitation of hemiparetic subjects in Europe, there is little neurophysiological evidence for its presumed effects on gait symmetry and facilitation of paretic muscles during the therapeutic intervention. The study, therefore, investigated the immediate effects of gait entrainment by a physical therapist on the gait of hemiparetic subjects. METHODS: Cycle parameters, gait symmetry, hip joint movement and the electromyographic activity of several lower limb muscles were assessed in 22 patients during a classic intervention by five Bobath therapists and while walking with and without a cane. RESULTS: Multivariate statistics revealed that, while being assisted by the therapist, patients walked faster (P = 0.022), with a longer relative stance period of the affected leg (P = 0.005), a higher symmetry (P = 0.002), larger hip extension (P = 0.001) and more activation (P = 0.026) of the Mm. triceps surae, vastus lateralis, biceps femoris and gluteus medius as compared to walking with and without a cane. Extensor spasticity of the plantar-flexor tended to increase (n.s.). In five subjects, no after-effect could be documented 1 h after a gait training of 30 min. CONCLUSIONS: The study confirmed a more balanced walking pattern in conjunction with facilitation of various weight bearing muscles during the therapeutic intervention. A prolonged single stance period of the affected leg, an unobstructed hip movement, enhanced weight acceptance and a faster gait seemed to be responsible for the observed immediate effects of the therapeutic intervention.

Asymmetry of gait initiation in hemiparetic stroke subjects.

OBJECTIVE: To investigate symmetry of gait initiation in healthy and hemiparetic subjects. DESIGN: Survey. SETTING: Kinematic laboratory affiliated with a hospital-based department of rehabilitation. PATIENTS OR OTHER PARTICIPANTS: Ten healthy and 14 hemiparetic stroke subjects starting five times with their right and left leg, respectively. MAIN OUTCOME MEASURES: Duration of defined periods, step length, center of pressure, and center of mass were recorded and calculated using two triaxial force plates, contact switches, and a video camera system. RESULTS: Healthy subjects displayed a high degree of independence of kinetic and kinematic parameters of the starting limb. Hemiparetic patients showed differences with respect to the starting limb: when starting with the nonaffected leg, the swing period and step length was shorter and the center of pressure displayed a more marked medio-lateral sway with no corresponding initial movement of the center of mass; when starting with the affected leg the movement pattern of the center of pressure and center of mass was comparable to that of normal subjects. CONCLUSIONS: The trajectories of the center of pressure and center of mass and the symmetry parameters are in accordance with a higher degree of uncertainty when starting with the non-affected limb in hemiparetic subjects.

Pyelonephritis provokes growth retardation and apoptosis in infant rat renal cortex.

Childhood pyelonephritis is a common cause of renal cortical scarring and hypoplastic kidneys. To understand the mechanisms underlying the cortical lesions, urinary tract infection was induced in three-week-old rats by an intravesical infusion of E. coli, type 06 K13 HL a rat nephropathogenic strain. Four days after infection, histopathological examination showed marked infiltration of leukocytes in the medullary tissue adjoining the calyces and pelvis. In the cortex, signs of inflammation were found only in the cortical zone adjacent to the pelvis. No cells indicative of inflammation were observed in other parts of the cortex. Immunohistochemistry for endogenous proliferating cell nuclear antigen (PCNA) demonstrated a marked decrease in immunoreactivity in proximal tubular (PT) cells. The mitotic response of PT cells, assessed by 3H-thymidine autoradiography, showed a highly significant decrease during the first four days after induction of the infection. Four days after infection, a transient increase in apoptotic cells was observed in cortical cells outside the inflammatory areas. No increase in apoptotic cells was detected in the cortex 10 days after infection. Only a few apoptotic cells were detected in the control kidneys. In conclusion, the data indicate that inhibition of cell proliferation and enhancement of apoptosis may contribute to the renal parenchymal loss after childhood pyelonephritis.

Racial group differences in plasma concentrations of antioxidant vitamins and carotenoids in hemodialysis patients.

Approximately 50% of the mortality in hemodialysis patients is due to cardiovascular disease. Antioxidant vitamins and carotenoids may be protective because oxidation of low-density lipoproteins appears to be a necessary prerequisite for the development of atherogenesis, and hemodialysis itself may stimulate the generation of oxygen reactive species. African Americans comprise a substantial proportion of dialysis patients because they have higher rates of hypertension, glomerulonephritis, and diabetic end-stage renal disease than do whites. The purpose of this cross-sectional study was to determine the plasma concentrations of antioxidant vitamins and carotenoids in hemodialysis patients and to investigate whether differences in these concentrations in the major racial or ethnic groups exist. Plasma concentrations of alpha- and gamma-tocopherol, carotenoids, and retinol were measured with HPLC and plasma vitamin C was measured with a spectrophotometric method in 109 white and African American hemodialysis patients. Dietary intakes of selected micronutrients were also compared by using data from a food-frequency questionnaire. Overall, plasma vitamin C and alpha-tocopherol concentrations were comparable but plasma carotenoid concentrations were lower than those reported for other populations. African American patients had significantly higher mean plasma concentrations of retinol (P < 0.04), lutein (P < 0.02), and total carotenoids minus lycopene (P < 0.04); whites had significantly higher mean plasma concentrations of alpha-tocopherol (P < 0.02), independent of age and plasma lipid concentrations. Diabetes comorbidity had an independent negative association with plasma beta-carotene concentration but was not associated with other measures.

Gait function in spastic hemiparetic patients walking barefoot, with firm shoes, and with ankle-foot orthosis.

The purpose of the study was to investigate the effect of firm shoes and a particular type of a frequently prescribed ankle-foot orthosis in Germany, the Valens calliper, on functional gait parameters in hemiparetic patients with marked extensor spasticity and corresponding heel-strike problems. Cycle times, vertical ground reaction forces, trajectories of the centre of pressure (gait line) under the soles and the mode of initial contact were assessed in 19 hemiparetic patients walking barefoot, with firm shoes and the orthosis. With the shoes, significant improvements (p < 0.006) were observed for: walking velocity, stride length, initial double stance duration and gait line of the non-affected foot. The pattern of the vertical force diagram improved qualitatively in six patients. With the orthosis the following variables showed an even more marked improvement (p < 0.006): walking velocity, cadence, stride length, and gait line of both the affected and non-affected foot. Fourteen patients became rear-foot strikers and the vertical force pattern further improved in six patients. It is concluded that the ankle-foot orthosis (more than the shoes) provide a useful support in the early rehabilitation of hemiparetic patients with marked spasticity.

Ankle muscle activity before and after botulinum toxin therapy for lower limb extensor spasticity in chronic hemiparetic patients.

BACKGROUND AND PURPOSE: Recent studies have been made of the novel treatment of lower limb spasticity after stroke with botulinum toxin A, and the results were based mostly on the clinical assessment made before and after treatment. This study investigated the effects of toxin on ankle muscle activity during gait in patients with severe extensor spasticity. The questions posed were whether the toxin particularly diminishes the so-called premature muscle activity as a major cause of equinovarus deformity and whether different types of altered motor control allow a prediction of the outcome of the treatment. METHODS: In 12 chronic hemiparetic outpatients with pronounced lower limb spasticity, we injected 400 U botulinum toxin A into the soleus and tibialis posterior muscles and both heads of the gastrocnemius muscles. Ankle spasticity and complex gait analysis including kinematic electromyography (EMG) of the soleus and tibialis muscles were assessed before treatment and 4 weeks after the injection. RESULTS: Nine patients profited with a reduction of spasticity, improved gait ability, and a more normal temporal pattern of muscle activity with a prominent reduction of the premature activity of the plantar flexors. Eight patients exhibited a qualitative pattern (type I) corresponding to an increased stretch-reflex excitability. Three patients did not profit; their muscle tone, gait ability, and muscle activation remained stable or even deteriorated. CONCLUSIONS: This study further supports the beneficial effects of botulinum toxin in the treatment of lower limb extensor spasticity. A correlation was observed between the clinical reduction of muscle tone, functional gait parameters, and a more normal EMG pattern with a predominant reduction of the premature activity of the plantar flexors. The qualitative type of EMG pattern corresponding to an increased stretch-reflex excitability (type I) was a positive predictor for the outcome.

Short-term electrical stimulation enhances the effectiveness of Botulinum toxin in the treatment of lower limb spasticity in hemiparetic patients.

The study tested the spasmolytic effect of Botulinum toxin A in two groups of hemiparetic patients with lower limb spasticity: in the first group (n = 5) 2000 U Dysport were injected into the soleus, tibialis posterior and both heads of gastrocnemius muscles alone; the second (n = 5) received additional repetitive alternating electrical stimulation of M. tibialis anterior and plantar flexors for 30 min six times per day during the 3 days following the injection. Muscle tone, rated by the Ashworth spasticity score, and gait analysis including recording of vertical ground reaction forces, were assessed before and 4 weeks after injection. The combined treatment proved to be more effective with respect to the clinically assessed reduction of muscle tone, gait velocity, stride length, stance- and swing-symmetry (P < 0.05). The result is discussed with reference to animal experiments demonstrating enhanced toxin uptake and accelerated onset of its paralytic effect by electrical stimulation.

Composition of human airway mucins and effects after inhalation of acid aerosol.

Characterization of normal airway mucus is required to elucidate mechanisms protecting the airways and to understand changes associated with disease and environmental insult. Toward this goal, we collected bronchial washes (10 ml saline) from healthy human subjects to 1) evaluate the yield of high-density material (delta > or = 1.35 g/ml), and 2) characterize glycoconjugates associated with collected secretions. Samples were lipid extracted followed by CsCl density gradient centrifugation. The yield of high-density material from individual subjects was variable but sufficient to demonstrate that mucin glycoproteins are a major constituent of mucus from healthy airways and that proteoglycans are absent. Next, we investigated whether inhalation of H2SO4 aerosol (1,000 microgram/m3), an environmental insult associated with alterations in mucociliary clearance, changes the composition of high-density glycoproteins in airway secretions. In a paired, double-blinded study, high-density fractions of bronchial secretions from 12 subjects were collected 18 h after exposures of 2 h to aerosolized NaCl and H2SO4. In all cases the high-density material displayed characteristics of mucin glycoproteins. In addition, a unique 150-kDa glycoprotein was detected in most but not all samples and may represent a small mucin glycoprotein differentially expressed in humans. No differences were noted between the two exposure conditions in the profiles of the glycoproteins or proteins after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Statistically, large changes with acid exposure in the composition of carbohydrates and amino acids were absent. Thus no substantial systematic changes in airway mucin glycoproteins or closely associated proteins and glycoproteins were correlated with H2SO4 exposure. Alternatively, statistical analysis of the differences between exposures in glycoprotein constituents among subjects denoted greater variability in carbohydrates compared with amino acids with repeated sampling, suggesting normal daily variations in the mucin composition of individual airway mucus.

Treadmill training with partial body weight support compared with physiotherapy in nonambulatory hemiparetic patients.

BACKGROUND AND PURPOSE: Treadmill training with partial body weight support is a new and promising therapy in gait rehabilitation of stroke patients. The study intended to investigate its efficiency compared with gait training within regular physiotherapy in nonambulatory patients with chronic hemiparesis. METHODS: An A-B-A single-case study design compared treadmill training plus partial body weight support (A) with physiotherapy based on the Bobath concept (B) in seven nonambulatory hemiparetic patients. The minimum poststroke interval was 3 months, and each treatment phase lasted 3 weeks. Variables were gait ability assessed by the Functional Ambulation Category, other motor functions tested by the Rivermead Motor Assessment, muscle strength assessed by the Motricity Index, muscle tone rated by the Modified Ashworth Spasticity Scale, and gait cycle parameters. RESULTS: Treadmill training was more effective with regard to restoration of gait ability (P < .05) and walking velocity (P < .05). Other motor functions improved steadily during the study. Muscle strength did not change, and muscle tone varied in an unsystematic way. The ratio of cadence to stride length did not alter significantly. CONCLUSIONS: Treadmill training offers the advantages of task-oriented training with numerous repetitions of a supervised gait pattern. It proved powerful in gait restoration of nonambulatory patients with chronic hemiparesis. Treadmill training could therefore become an adjunctive tool to regain walking ability in a shorter period of time.

Eye movements and fixation characteristics in perception of stationary scenes: normal subjects as compared to patients with visual neglect or hemianopia.

Saccade amplitudes, fixation times, and the spatial distribution of fixation points were comparatively studied in patients with visual hemineglect and/or homonymous hemianopia, as well as in normals (each group, n = 8). Two types of picture slides were presented (with and without search task) while eye movements were recorded with the infrared reflection technique. Self-developed software served to detect fixations, and to document their spatio-temporal parameters. Spectra of saccade amplitudes and fixation times were characteristic of each slide, while exhibiting notable similarities across subject groups. It is concluded that foveal information processing may not be much different in patients and in normals. Average saccade amplitudes and total scanpath lengths across all pictures were significantly smaller in the patients than in normals with both types of slides. In the neglect patients, saccades starting and terminating in the unaffected visual hemifield were larger, on an average, than those entirely located in the affected hemifield. The same was true for many of the hemianopic patients. Nevertheless, during free exploration, mean amplitudes of saccades restricted to the unaffected hemifield of the patients were apparently still smaller than those of normal controls within the corresponding hemifield. Average dwell time of fixations, total fixation time, as well as the total number of fixations did not vary significantly between groups. However, in the patient groups, average fixation times were shorter after large as compared to small saccades. This finding is discussed in the context of saccadic programming on the background of the sequential attention model of eye movement control. In subsamples of five hemianopic and six neglect patients, asymmetry in the distribution of fixation points was compared before and after a 4-week period of comprehensive rehabilitation that Included computerized scanning and attentional training. Only patients with pure hemianopia (who were less severely impaired from the beginning) improved according to this criterion, while neglect patients remained unchanged or deteriorated slightly. Total scanpath lengths, however, were not significantly different before and after therapy in any of the two groups of patients, indicating a persisting disturbance in scanning performance also in the hemianopic group.

Gait outcome in ambulatory hemiparetic patients after a 4-week comprehensive rehabilitation program and prognostic factors.

BACKGROUND AND PURPOSE: Although gait training is prominent in the rehabilitation of hemiparetic stroke patients, little is known about its outcome and prognostic factors in mildly affected patients. We therefore intended to assess gait in ambulatory stroke patients before and after a 4-week inpatient rehabilitation program based on the neurodevelopmental technique. METHODS: We measured vertical ground reaction forces by force plates in 148 stroke patients. Variables were stance durations, peak vertical ground reaction forces at heel strike (Fz1) and toe-off (Fz2), loading and deloading rates, time to Fz1, and time to Fz2. The absolute changes for both legs and symmetry outcome were calculated. In addition, we assessed maximal walking speed, walking endurance, stair climbing ability, and the Motricity Index. RESULTS: Stance duration, weight acceptance, push-off of both legs, and the stance duration symmetry improved independent of changes of gait velocity. The symmetry of the ground reaction forces did not improve. Results were even worse for Fz1 and the loading rate at the end of treatment. Sex, age, side of hemiparesis, motor strength, stroke interval, and sensory impairment had no influence on the outcome of symmetry. Functional performance did not improve considerably. CONCLUSIONS: The absolute changes of the ground reaction forces indicated better weight acceptance and push-off of both legs and thus confirmed the efficacy of the neurodevelopmental technique. The symmetry outcome and the functional performance at the end of treatment, however, challenge the efficacy of intensive rehabilitation therapy for 4 weeks in its attempts to restore physiological gait in these mildly affected patients.

Quantitative analysis of rising from a chair in healthy and hemiparetic subjects.

In 15 healthy and 20 hemiparetic persons we studied standing-up by two force-plates. Phases before and after the seat-off, force distribution and centre of gravity displacement were assessed. The patients rose significantly slower. The force ratios after seat-off differed significantly between the groups (0.88 vs 0.68). Left/right hemiparetic patients put more weight on the affected limb in 18%/11% of the trials before seat-off, with its insufficient use after it mainly in the left patients. At seat-off, projection of the centre of gravity fell within the support area in hemiparetic patients, and 3 cm behind it in healthy subjects. With larger lateral displacement of the centre of gravity in the hemiparetic group, left hemiparetic patients mostly shifted their weight to the non-affected side and right hemiparetic patients to both sides. Weight distribution and mediolateral displacement of the centre of gravity in the left and right hemiparetic patients were considered.

Mortality in diabetic patients with cardiovascular autonomic neuropathy.

Cardiovascular autonomic diabetic neuropathy (CADN) may carry an increased risk of mortality. However, in previous studies the prognosis of patients with CADN seemed to be influenced by life-threatening macro- and microvascular complications which had already been present at the start of the study period. Between 1981 and 1983, 1015 diabetic patients have been examined for CADN (abnormal heart rate variation at rest and during deep respiration) at the Diabetes Research Institute, Düsseldorf. Thirty-five patients (28 with Type 1 diabetes, 7 with Type 2 diabetes) with CADN have been retrospectively recruited and reviewed 8 years later and compared with 35 patients without CADN who were matched for sex, age, and duration of diabetes. Exclusion criteria for entry into the study included severe micro- or macrovascular complications, such as proliferative retinopathy, proteinuria or symptomatic coronary artery disease. During the 8-year observation period, 8 patients with CADN and 1 patient without CADN died. The survival rate estimates steadily declined in patients with CADN over the whole period studied. The 8-year survival rate estimate in patients with CADN was 77% compared with 97% in those with normal autonomic function (p < 0.05). Deaths were mainly due to macrovascular diseases (n = 3) and sudden unexpected deaths (n = 3). One patient with CADN died after an episode of severe hypoglycaemia. Among the decreased patients, coefficient of variation of R-R intervals during deep breathing was significantly reduced when compared with those who survived (1.04 +/- 0.5% vs 1.87 +/- 1.0%; p < 0.05), and symptoms of autonomic neuropathy (orthostatic hypotension, gastroparesis, gustatory sweating) were more frequent (7/8 vs 10/27 patients).(ABSTRACT TRUNCATED AT 250 WORDS)