ABSTRACT
The human Fc receptor, FcgammaRIIA, is known to mediate phagocytosis and endocytosis, yet the greatest numbers of these receptors are expressed on the surface of non-phagocytic platelets, where they are involved in serotonin secretion. FcgammaRIIA harbours three tyrosine (Y) residues within its cytoplasmic domain. Y1 is upstream of both Y2 and Y3, which are contained within an immunoreceptor tyrosine-based activation motif (ITAM), required for many signaling events. We have demonstrated that the two ITAM tyrosines are required for phagocytic signaling and that mutation of a single ITAM tyrosine decreases but does not abolish phagocytic signaling. Furthermore, we have identified that the YMTL motif is required for endocytosis. These observations suggest that FcgammaRIIA utilizes different sequences for various signaling events. Therefore, we investigated the sequence requirements for another important FcgammaRIIA-mediated signaling event, serotonin secretion, using Rat Basophilic Leukemia (RBL-2H3) cells transfected with wildtype (WT) FcgammaRIIA or mutant FcgammaRIIA. Stimulation of cells expressing WT FcgammaRIIA induced release of serotonin at a level 7-fold greater than that in nonstimulated WT FcgammaRIIA-transfected cells or nontransfected RBL cells. Mutation of either ITAM tyrosine (Y2 or Y3) to phenylalanine was sufficient to abolish serotonin secretion. Further, while inhibition of Syk with piceatannol blocked phagocytosis as expected, it did not inhibit serotonin secretion. Additionally, inhibition of phosphoinositol-3-kinase (PI3K) with wortmannin only had a partial effect on serotonin signaling, despite the fact that the concentrations used completely abolished phagocytic signaling. These data suggest that the requirements for serotonin secretion differ from those for phagocytosis mediated by FcgammaRIIA.
Subject(s)
Blood Platelets/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Receptors, IgG/metabolism , Serotonin/metabolism , Signal Transduction/physiology , Animals , Cell Line, Tumor , Cytoplasm/metabolism , Phagocytosis/physiology , Protein-Tyrosine Kinases/metabolism , Rats , TransfectionABSTRACT
Alfalfa plants form bacteria-free nodules in response to a number of agents, including Rhizobium meliloti exo mutants, Agrobacterium tumefaciens transconjugants carrying cloned R. meliloti nodulation genes, and compounds that function as auxin transport inhibitors, N-( 1-naphthyl)phthalamic acid or 2,3,5-triiodobenzoic acid. These bacteria-free nodules contain transcripts for the nodulins Nms30 and MsENOD2; transcripts for late nodulins like leghemoglobin are not detected. In situ hybridization studies demonstrated that ENOD2 transcripts were localized in parenchyma cells at the base and along the periphery of nitrogen-fixing alfalfa root nodules. The ENOD2 gene was also expressed in a tissue-specific manner in nodules elicited by N-( 1-naphthyl)phthalamic acid and 2,3,5-triiodobenzoic acid. In bacteria-free nodules induced by R. meliloti exo mutants and A. tumefaciens transconjugants carrying either one or both R. meliloti symbiotic plasmids, ENOD2 transcripts were also detected but were usually localized to parenchyma cells at the base instead of along the periphery of the nodule. On the basis of the pattern of ENOD2 gene expression, we conclude that the developmental pathway of bacteria-free nodules, whether bacterially or chemically induced, is the same as that of nitrogen-fixing nodules, and, furthermore, that the auxin transport inhibitors in their action mimic some factor(s) that trigger nodule development.
ABSTRACT
The collection of symbiotic (sym) mutants of white sweetclover (Melilotus alba Desr.) provides a developmental sequence of mutants blocked early in infection or nodule organogenesis. Mutant phenotypes include non-nodulating mutants that exhibit root-hair deformations in response to Rhizobium meliloti, mutants that form ineffective nodules lacking infection threads, and mutants that form infection threads and ineffective nodules. Mutant alleles from both the sym-1 and the sym-3 loci exhibited a non-nodulating phenotype in response to R. meliloti, although one allele in the sym-1 locus formed ineffective nodules at a low frequency. Spot-inoculation experiments on a non-nodulating allele in the sym-3 locus indicated that this mutant lacked cortical cell divisions following inoculation with R. meliloti. The auxin transport inhibitor N-(1-naphthyl)phthalamic acid elicited development of pseudonodules at a high frequency on all of the sweetclover sym mutants, including the non-nodulating mutants, in which the early nodulin ENOD2 was expressed. This suggests that N-(1-naphthyl)phthalamic acid activates cortical cell divisions by circumventing a secondary signal transduction event that is lacking in the non-nodulating sweetclover mutants. The sym-3 locus and possibly the sym-1 locus appear to be essential to early host plant responses essential to nodule organogenesis.
ABSTRACT
Exposure of lymphocytes from guinea pigs sensitized to keyhole limpet hemocyanin and of macrophages from nonsensitized animals to noncytotoxic doses of lidocaine (10(-4) to 10(-6) M) resulted in the inhibition of the production of macrophage migration inhibitory factor and of macrophage motility. The inhibition of both processes was related to the concentration of lidocaine in the medium. The effects of lidocaine, a membrane-stabilizing drug, were apparently related to its ability to interact with the cell surface and cause changes in the surface ionic configuration of the cells, as determined by cell electrophoresis. The drug conferred permanent changes in the surface of lymphocytes at all concentrations tested, but the changes in the surface of macrophages induced in the presence of 10(-5) and 10(-6) M of the drug were reversible. The presence of noncytotoxic doses of lidocaine in the cellular environment resulted in significant changes in cellular functions that appeared to be related to the ability of the drug to interact with cell membranes in a manner determined by the specific surface properties of the cell.
Subject(s)
Lidocaine/pharmacology , Lymphocytes/metabolism , Macrophage Migration-Inhibitory Factors/biosynthesis , Macrophages/cytology , Animals , Cell Movement , Cell Separation , Electrophoresis , Female , Guinea PigsABSTRACT
The purpose of this work was to get insight into the role of frontal trunk and proximal extremity muscles in rolling from supine to side lying. Participants were seventeen hemiparetic patients and 14 healthy subjects. Electromyographic (EMG) activity of the Sternocleidomasoid (ScM), Pectoralis Major (PM), External Oblique (ExO) and Rectus Femoris (RF) muscle pairs was recorded during rolling performance. Analysis included the establishment of EMG response times and magnitudes. For all muscles, initiation of EMG activity was delayed in the patients as compared with the controls. Among the healthy subjects, EMG activity level of the SCM was more enhanced on the mobile than on the stable body side, while activation level of the PM muscle was larger on the stable body side. In the hemiparetic group, the SCM demonstrated similar results as the controls yet, PM activity on the paretic side was lower than on the non-paretic side regardless of rolling direction. The difference in activation level between the corresponding ExO and RF muscles showed inconsistency among the healthy subjects, whereas in the hemipareic group the muscles on the paretic side never displayed higher activation levels than on the non-paretic side. In conclusion, rolling sideways in hemiparetic subjects is characterized by a normal relationship between activation levels of the SCM muscles while the relationship between the corresponding PM, ExO and RF muscles is hampered due to reduced activation level of the muscles on the paretic body side.
Subject(s)
Motor Skills , Muscle, Skeletal/physiopathology , Paresis/rehabilitation , Stroke Rehabilitation , Aged , Electromyography , Extremities/physiology , Extremities/physiopathology , Female , Humans , Male , Paresis/physiopathology , Physical Therapy Modalities , Rotation , Stroke/physiopathologyABSTRACT
While standing, light fingertip touch on an external stable object attenuates sway and improves balance in healthy adults as well as in individuals with poor postural control. The effect of light touch on balance during gait is, however, not well known. Therefore, the purpose of this work was to study the effects of light fingertip touch on balance during gait. We hypothesized that similar to its effect during stance light touch would increase postural stability. Forty healthy young adults were tested under four gait conditions: (1) eyes open (EO), (2) eyes closed (EC), (3) eyes closed while lightly touching a static object on the right side of the walking lane (ECLTS), (4) eyes closed while lightly touching a dynamic object, namely, a stick that was moved forwards by the subject with the right hand (ECLTD). The main outcome measure was medio-lateral step width variability, a well established indicator of gait balance in the medio-lateral plane. During the EC condition, light touch of an external static object (ECLTS) decreased medio-lateral variability (i.e., balance improved); however, this stabilizing effect was not observed with light touch on the stick. The availability of self positional and spatial cues when touching a static external reference, and their absence when touching a stick that is moved forwards by the subject as he walks, can explain the different effects of light touch in the ECLTS vs the ECLTD gait conditions.
Subject(s)
Gait , Postural Balance , Touch , Adolescent , Adult , Female , Humans , Male , Young AdultABSTRACT
The alfalfa ENOD8 nodule-specific gene is expressed in empty nodules elicited by exopolysaccharide-deficient Rhizobium meliloti, and it is expressed early in nodule development. An ENOD8 cDNA was sequenced and found to encode a novel product. Its deduced polypeptide sequence was found to be similar to the nonproline-rich domains of the putative polypeptides encoded by a class of anther-specific genes from Arabidopsis thaliana and Brassica napus. The role of the ENOD8 gene product is predicted to be in nodule organogenesis. ENOD8 is expressed in a developmental pathway triggered as a result of Rhizobium nodulation signal transduction.
Subject(s)
Genes, Bacterial , Medicago sativa/genetics , Membrane Proteins , Nitrogen Fixation/genetics , Plant Proteins/genetics , Amino Acid Sequence , Arabidopsis/genetics , Base Sequence , Brassica/genetics , DNA, Complementary , Molecular Sequence Data , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Sinorhizobium meliloti/geneticsABSTRACT
We have cloned alfalfa nodule-specific cDNAs that code for leghemoglobin (Lb), glutamine synthetase (GS), and three unidentified nodulins. Hybrid-select translation of nodule RNA followed by 2-D gel electrophoresis showed that the Lb-specific cDNA corresponded to at least four Lb species of 12 kDa. One of the unidentified cDNA clones (N-32/34) corresponded to at least five polypeptides of 32-34 kDa; a second unidentified cDNA clone (N-14) corresponded to an individual polypeptide of 14 kDa. The in vitro translation product(s) of the RNA hybrid selected by the third unidentified cDNA clone (N-22) formed a single band at 22 kDa on a one-dimensional gel. Northern and dot blot analyses of RNA isolated from wild-type nodules and from defective nodules elicited by a variety of Rhizobium meliloti mutants showed that 1) RNAs corresponding to the Lb, nodule-specific GS, and three unidentified nodulins were coordinately expressed during the course of nodule development, and 2) all five nodulins were expressed in Fix- nodules that contained infection threads and bacteroids but were not expressed in nodules that lacked infection threads and intracellular rhizobia.
Subject(s)
Gene Expression Regulation , Glutamate-Ammonia Ligase/genetics , Medicago sativa/genetics , Membrane Proteins , Plant Proteins/genetics , Base Sequence , Blotting, Northern , Cloning, Molecular , DNA , Electrophoresis, Gel, Two-Dimensional , Electrophoresis, Polyacrylamide Gel , Kinetics , Medicago sativa/growth & development , Molecular Sequence Data , Protein BiosynthesisABSTRACT
The association of intraventricular conduction defects and aortic valvular disease is widely recognized. This study was undertaken to evaluate the effects on survival of left bundle conduction defects (LBCDs) as a consequence of aortic valve replacement. A total of 133 patients were followed between 1 and 70 months after operation, with a mean follow-up of 32.1 months. The incidence of intraoperative LBCDs was 31.6% or 42 patients. There were 13 deaths in the group of 42 patients with LBCDs compared to eight deaths in the group of 91 patients without such abnormalities (p less than 0.01). Sudden death occurred in five of 42 patients with postoperative LBCDs and two of 91 patients with normal intraventricular conduction (p less than 0.025). The survival rate in these patients with significant aortic stenosis and normal intraventricular conduction was 89.9%, whereas if LBCD had occurred after operation, the survival rate was 65.7% (p less than 0.005). If the LBCD was accompanied by a left axis deviation, the survival rate was 21.7%. Sudden death may be due either to a tachyarrhythmia or perhaps to progression from LBCD to complete heart block or trifascicular block. It is important that this group of patients be monitored closely after operation. There may be an indication to insert prophylactic permanent pacemakers in this group.
Subject(s)
Aortic Valve/surgery , Heart Block/etiology , Heart Valve Prosthesis/adverse effects , Aortic Valve Insufficiency/surgery , Aortic Valve Stenosis/mortality , Aortic Valve Stenosis/surgery , Follow-Up Studies , Heart Block/mortality , Humans , Intraoperative Complications , Prognosis , Tachycardia/etiology , Tachycardia/mortalityABSTRACT
OBJECTIVE: The objective of the present study was to examine time-related changes in motor performance of daily tasks of the upper extremity ipsilateral to the side of lesion in poststroke hemiparetic patients. METHODS: Nine patients after an acute uniliteral cerebrovascular accident and 10 age-matched healthy controls were studied. Functional motor abilities of the upper extremity ipsilateral to side of lesion were examined over a 4-month time course, using validated measurement tools (Jebsen test of hand function, nine-hole peg test, and three functional activities of daily living). RESULTS: The results indicated a significant impairment in the motor function of the hand ipsilateral to the side of brain lesion in comparison with the matched extremity in control subjects. They also pointed to time-related improvement in performance speed, implying that the deterioration in the functional performance of the upper extremity on the uninvolved body side of poststroke hemiparetic patients is not static and may improve with time. The findings further suggested that the left hand of patients with an intact right cerebral hemisphere improves more than does the right hand of their peers whose left cerebral hemisphere is intact. CONCLUSIONS: Due to the small sample size and methodologic considerations, further and more extensive work is required to determine difference in improvement in motor abilities of the ipsilateral left versus the ipsilateral right upper extremities in stroke survivors.
Subject(s)
Psychomotor Performance , Stroke Rehabilitation , Stroke/physiopathology , Activities of Daily Living , Aged , Functional Laterality , Humans , Middle Aged , Paresis/physiopathology , Paresis/rehabilitation , Reaction Time , Recovery of FunctionABSTRACT
Cells cultured from xeroderma pigmentosum (XP) patients are defective in excision repair of damaged DNA specifically at the incision step. In Escherichia coli this step is mediated by the UvrA, UvrB and UvrC gene products. Our goal is to express each of these genes in XP cells, singly or in combination, and to determine the most suitable conditions for generating faithful E. coli Uvr protein copies in functional concentrations and properly localized for the eventual repair of damaged chromosomal DNA or DNA which is introduced exogenously. The E. coli gpt gene in pSV2gpt is used as a selection marker for uvr gene transfection into XP cells. The uvr genes were cloned into composite pBR322, SV40 and gpt vectors in which each E. coli gene is flanked by individual SV40 regulatory elements. SV40-transformed XP-A cells were transfected with pSV2uvrASV2gpt, gpt+ colonies were selected, and cell lines established. Several lines were examined in detail. Cell lines 714 and 1511 contain uvrA together with flanking SV40 regulatory elements integrated intact in genomic DNA and express UvrA protein as well as a 95,000-dalton UvrA-related protein. The expression of uvrA was found to be 50-100-fold lower than the expression of gpt. Attempts were made to assay the mammalian UvrA protein for functionality, but endogenous activities interfered with assays for each of the UvrA protein's three activities. The peptide maps derived from partial proteolysis of the "mammalian" UvrA protein are identical to the E. coli UvrA protein. The sub-cellular location of UvrA protein in uvrA+ XP cells was investigated by fractionation of cell extracts in which an indirect immunofluorescence method revealed its location as being largely extra-nuclear. Two uvrA+ cell lines were examined for their UV-resistant phenotype and not unexpectedly were found not to be reverted to a state of repair proficiency.
Subject(s)
Bacterial Proteins/genetics , DNA Repair , Genes, Bacterial , Xeroderma Pigmentosum/enzymology , Bacterial Proteins/metabolism , Cell Compartmentation , Genetic Complementation Test , Humans , Peptide Fragments/analysis , Transfection , Ultraviolet Rays , Xeroderma Pigmentosum/geneticsABSTRACT
The purpose of this work was to determine whether fingertip touch on a stable surface could improve postural stability during stance in subjects with somatosensory loss in the feet from diabetic peripheral neuropathy. The contribution of fingertip touch to postural stability was determined by comparing postural sway in three touch conditions (light, heavy and none) in eight patients and eight healthy control subjects who stood on two surfaces (firm or foam) with eyes open or closed. In the light touch condition, fingertip touch provided only somatosensory information because subjects exerted less than 1 N of force with their fingertip to a force plate, mounted on a vertical support. In the heavy touch condition, mechanical support was available because subjects transmitted as much force to the force plate as they wished. In the no touch condition, subjects held the right forefinger above the force plate. Antero-posterior (AP) and medio-lateral (ML) root mean square (RMS) of center of pressure (CoP) sway and trunk velocity were larger in subjects with somatosensory loss than in control subjects, especially when standing on the foam surface. The effects of light and heavy touch were similar in the somatosensory loss and control groups. Fingertip somatosensory input through light touch attenuated both AP and ML trunk velocity as much as heavy touch. Light touch also reduced CoP sway compared to no touch, although the decrease in CoP sway was less effective than with heavy touch, particularly on the foam surface. The forces that were applied to the touch plate during light touch preceded movements of the CoP, lending support to the suggestion of a feedforward mechanism in which fingertip inputs trigger the activation of postural muscles for controlling body sway. These results have clinical implications for understanding how patients with peripheral neuropathy may benefit from a cane for postural stability in stance.
Subject(s)
Diabetic Neuropathies/physiopathology , Fingers/physiology , Peripheral Nervous System Diseases/physiopathology , Postural Balance/physiology , Touch , Aged , Female , Humans , Male , Middle Aged , Posture/physiology , ProprioceptionABSTRACT
BACKGROUND AND PURPOSE: This work was designed to study the effects of bilateral elbow flexion on the reaction and movement times of the impaired upper extremity of patients with hemiparesis. SUBJECTS: The subjects consisted of an experimental group of patients with hemiparesis (n = 25) and a control group of age-matched healthy volunteers (n = 26). METHODS: Each subject performed three sets of 16 elbow flexion trials. Two of these sets required unilateral movements, one for each upper extremity. The third set of movements required simultaneous elbow flexions of both upper extremities. In each trial, subjects were instructed to flex their elbows in response to an auditory signal from a supported initial position of 150 degrees through a goal orientation of 120 degrees. "Reaction time" was defined as the time between the auditory signal and movement initiation. "Movement time" was defined as the time between movement initiation and the completion of 30 degrees of elbow flexion. RESULTS: When subjects were asked to bilaterally flex their elbows, the reaction and movement times increased in both extremities. CONCLUSION AND DISCUSSION: It was speculated that in patients with hemiparesis, movement time of the nonparetic extremity in the bilateral task is limited by the rate of performance of the paretic extremity. The decrease in speed of these performance-determining variables in the bilateral task warrants consideration during physical therapy intervention for patients with hemiparesis.
Subject(s)
Elbow Joint/physiology , Hemiplegia/physiopathology , Movement/physiology , Reaction Time/physiology , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Physical Therapy Modalities , Reference ValuesABSTRACT
The study was designed to examine major weight-bearing characteristics of hemiplegic patients receiving physical therapy and to assess the usefulness of the Foot Print apparatus as an objective, clinical measurement tool of these characteristics. Measurements of the foot-ground pressure pattern of 23 patients were taken two times, three weeks apart. The results confirmed the clinical impression of lesser weight bearing by the patient on the affected leg, especially on the heel of that leg, compared with weight bearing on the contralateral leg. Consequently, stance stability was impaired. The difference between the foot-ground pressure of the two measurements indicated improvement in the stance characteristics of these patients after treatment. The Foot Print apparatus seems to be an objective measurement tool of assistance both to the patient and the physical therapist in execution of a treatment.
Subject(s)
Dermatoglyphics , Hemiplegia/rehabilitation , Physical Therapy Modalities/methods , Aged , Body Weight , Female , Humans , Leg , Male , PressureABSTRACT
This study was undertaken to evaluate the influence of weight shift over the affected leg of standing hemiplegic patients on the electromyographic responses of the medial gastrocnemius and tibialis anterior muscles during continuous anterior-posterior movements of the base of support. Recordings were taken from 10 hemiplegic subjects and from 9 healthy subjects of comparable age. Each subject was first tested standing with both feet on a level surface and then with either leg (in healthy subjects) or the unaffected leg (in hemiplegic subjects) raised on a step. The second testing position caused unloading of the elevated leg and weight shift, that is, loading of the other leg. The measured variables were modulation of muscular activity, determined by a modulation index formulated for that purpose, and the relative amount of integrated electromyographic activity in each muscle. Changes in both variables in the uneven stance position as compared with even stance, occurred primarily in the unaffected (unloaded) leg in the hemiplegic subjects. These changes were comparable to changes in the unloaded leg of the healthy subjects. Thus, imposed loading on the affected leg of the hemiplegic subjects did not significantly improve either the reduced modulation or the relatively low IEMG activity of the investigated muscles. Further studies are required to evaluate the contribution of weight shift to recovery of postural responses in the affected leg of hemiplegic patients.
Subject(s)
Hemiplegia/physiopathology , Leg/physiopathology , Muscles/physiopathology , Ankle Joint/physiopathology , Electromyography , Female , Hemiplegia/rehabilitation , Humans , Male , Middle Aged , PostureABSTRACT
The purpose of this study was to compare the therapeutic efficacy of three exercise therapy approaches. Three groups of adult stroke patients (N = 131) participated in the study. The first group received conventional treatment that consisted of traditional exercises and functional activities. The treatment of the second group was based on proprioceptive neuromuscular facilitation techniques. The third group was treated using the Bobath approach. The improvement of each patient was evaluated after six weeks of treatment in terms of functional gains in activities of daily living as measured using the Barthel index, changes in the muscle tone of the involved limbs as measured using a five-point ordinal scale, changes in the isolated motor control of the ankle and wrist as measured by tests of muscle strength and range of motion, and changes in the patients' ambulatory status as measured using a nominal scale of four categories. The therapeutic effects of exercise according to each of the three approaches were compared using descriptive and nonparametric statistical methods. No substantial advantage could be attributed to any one of the three therapeutic approaches.
Subject(s)
Cerebrovascular Disorders/rehabilitation , Exercise Therapy/methods , Activities of Daily Living , Aged , Ankle Joint/physiopathology , Female , Functional Laterality , Gait , Hemiplegia/rehabilitation , Humans , Male , Muscle Tonus , Physical Therapy Modalities , Pilot Projects , Wrist Joint/physiopathologyABSTRACT
The responses of the medical gastrocnemius and tibialis anterior muscles to continuous sinusoidal perturbation of the base of support were studied in two groups of subjects, forty-two volunteers aged 20 to 84 years and 17 hemiplegic patients aged 52 to 81 years. EMGs were recorded while subjects stood on a platform oscillating in the anterior-posterior direction. Movement amplitude was adjusted to the maximum the subject could sustain without assisted support within the limits of the instrument. In healthy subjects, two basic activation modes were indicated: (a) a reciprocal contraction pattern in which activity of the medial gastrocnemius and tibialis anterior muscles was concentrated in the anterior and posterior half of the oscillation, respectively. This pattern prevailed in the younger subjects whose maximal movement amplitude reached the highest limit of the instrument; (b) a less discrete pattern, characterized by tonic contraction and periods of coactivation of the two muscles, was seen in older subjects who had difficulties in maintaining stance on the moving platform. The disruption of the discrete reciprocal response mode in this group of patients was related to decline in function of postural mechanisms with aging and demanded additional stiffening of the ankle join, presumably a manifestation of reduced automatism in favor of closer CNS modulation. The typical response mode in the sound leg of the hemiplegic patients was variable coactivation of the two muscles. In the afflicted leg, the establishment of a motor set was impaired: Low tone was associated with negligible muscular activity, although with more elevated tone, low level uniform cocontraction was evident.
ABSTRACT
This study was undertaken to investigate the contribution of a weight-relieving system on the gait of patients with severe locomotor disabilities. Temporal parameters of gait and subjective evaluations of the effect of the system were studied in 24 patients and 6 healthy subjects. Partial weight relief was accomplished through a pneumatic system mounted in the ceiling over a conductive walkway which was placed between parallel bars. Subjects were tested in three walking trials: free walking, walking while harnessed to the system but without weight relief, and walking with relief of 20 percent of their body weight. Temporal measurements indicated a positive effect of the system on duration of the stance and swing phases. The percentage of the stance period of the involved lower limb relative to the uninvolved one increased by 148 percent; at the same time, the swing period of the involved limb relative to the sound one decreased to 68 percent of that value in free ambulation. A substantial increase in gait symmetry and velocity were also noted. Subjective information from the patients and observers also pointed to a facilitative effect of the system on the patients' ambulation. Conversely, natural gait velocity of the healthy subjects was impeded by weight relief through the system.
Subject(s)
Amputation, Surgical/rehabilitation , Body Weight , Gait/physiology , Hemiplegia/rehabilitation , Paraplegia/rehabilitation , Adult , Aged , Aged, 80 and over , Humans , Middle Aged , Reference ValuesABSTRACT
The objective of this study was to compare the effects of conventional over-ground gait training with treadmill training on the restoration of gait in people with hemiparesis following a stroke. Twenty-five individuals in the early stages of rehabilitation were alternately assigned to one of two treatment groups. In addition to conventional physical therapy, the experimental group participated in 15 treadmill-training sessions in which a handrail was used for external support. The control group received the same number of equal length sessions of over-ground ambulation. Treatment effects were established by pre- and posttreatment assessment of: 1) functional walking ability, 2) walking speed, 3) stride length, 4) temporal characteristics of gait, and 5) electromyographic activity of calf muscles. Normal values were obtained from eight healthy individuals of approximately the same age as the stroke survivors. The study demonstrates that individuals following a stroke are well able to tolerate treadmill training in the early stage of their rehabilitation process without the use of a weight support apparatus. Furthermore, the findings suggest that treadmill training may be more effective than conventional gait training for improving some gait parameters such as functional ambulation, stride length, percentage of paretic single stance period, and gastrocnemius muscular activity.
Subject(s)
Exercise , Hemiplegia/rehabilitation , Physical Therapy Modalities/methods , Stroke Rehabilitation , Walking/physiology , Aged , Analysis of Variance , Disability Evaluation , Electromyography , Female , Gait , Hemiplegia/physiopathology , Humans , Male , Muscle, Skeletal/physiopathology , Statistics, Nonparametric , Stroke/physiopathologyABSTRACT
BACKGROUND AND PURPOSE: Evaluating proprioception is relevant to physical rehabilitation because of its significance in motor control. One method of proprioceptive testing involves having subjects either imitate or point at a joint position or movement which was presented via a passive movement. However, as the muscle spindles are subject to central fusimotor control, the proprioceptive system may be better-tuned to movements created by active muscular contraction than to passive movements. The objective of the present study was to determine whether accuracy of reproducing hand position is dependent on whether proprioceptive input is obtained via an active or a passive movement. METHOD: Thirty-nine healthy volunteers (mean age (+/- SD) 24.6 (+/- 3.6) years) participated in the study. Subjects' right hands, which were obscured from view, were acoustically guided to five targets on a digitizer tablet with either an active or passive upper extremity movement. Subjects were then asked to reproduce the targets' location by either reaching to them with the unseen hand or by use of a laser beam. Distance from target and angular deviations were calculated in both absolute and relative terms. Repeated measures analysis of variance (ANOVA) was performed for each variable followed by predetermined contrasts. RESULTS: Comparison between the active and passive conditions when reconstruction of target location was guided kinaesthetically indicates significant differences in absolute distance, range and angular deviation. The comparison when reconstruction of target location was guided visually indicates significant differences in absolute distance, absolute angle and angular deviation. CONCLUSIONS: The ability to reproduce hand position accurately is enhanced when position is encoded by active upper extremity movement compared with passive movement. The results have implications for the design of strategies for evaluating as well as treating patients with impaired proprioception and limited movement.