Involvement of occupational therapy departments in research: a provincial survey.

It is increasingly recognized that research is necessary to advance the practice of occupational therapy. The objective of this study was to determine whether occupational therapy departments in Quebec were commonly involved in research, and whether participation varied with the size of department and type of work setting. Secondly, enablers and barriers to participation in research were identified. A random sample of occupational therapy departments, stratified by size, were surveyed by mail. Participation rate was 74.8% (107/143). Participation in research was noted in half of the departments surveyed (51/107), most frequently as collaborator. Involvement in research was associated (p < .001) with a greater number of therapists in the department. Furthermore, occupational therapy departments in rehabilitation centres and in university hospitals were more likely to participate in research (79% and 90% respectively), whereas participation was lower for long-term care facilities (29%) and community health clinics (38%). When asked to rank factors that may facilitate participation in research, the highest rankings were given to: time allotted to research, research as a priority for administration, adequate financial support, and presence of an occupational therapy researcher and a research centre on site. This survey demonstrates that a number of factors can promote or prevent the realization of research activities within the clinical setting. Strategies are proposed to enhance the integration of research into clinical practice.

Structure of the human anti-apoptotic protein survivin reveals a dimeric arrangement.

Survivin is a 16.5 kDa protein that is expressed during the G2/M phase of the cell cycle and is hypothesized to inhibit a default apoptotic cascade initiated in mitosis. This inhibitory function is coupled to survivin's localization to the mitotic spindle. To begin to address the structural basis of survivin's function, we report the X-ray crystal structure of a recombinant form of full length survivin to 2.58 A resolution. Survivin consists of two defined domains including an N-terminal Zn2+-binding BIR domain linked to a 65 A amphipathic C-terminal alpha-helix. The crystal structure reveals an extensive dimerization interface along a hydrophobic surface on the BIR domain of each survivin monomer. A basic patch acting as a sulfate/phosphate-binding module, an acidic cluster projecting off the BIR domain, and a solvent-accessible hydrophobic surface residing on the C-terminal amphipathic helix, are suggestive of functional protein-protein interaction surfaces.

Dual role of pseudosubstrate in the coordinated regulation of protein kinase C by phosphorylation and diacylglycerol.

The activity of protein kinase C is reversibly regulated by an autoinhibitory pseudosubstrate, which blocks the active site of the enzyme in the absence of activators. However, before it can be allosterically regulated, protein kinase C must first be processed by three ordered phosphorylations, the first of which is modification of the activation loop catalyzed by the phosphoinositide-dependent kinase-1 (PDK-1). Here we use limited proteolysis to show that 1) newly synthesized protein kinase C adopts a conformation in which its pseudosubstrate sequence is removed from the active site, and 2) this exposure is essential to allow PDK-1 to phosphorylate the enzyme. Precursor (unphosphorylated) protein kinase C betaII obtained by 1) in vitro transcription and translation, 2) expression of a phosphorylation-deficient mutant (T500V), or 3) in vivo labeling with a pulse of [(35)S]cysteine/methionine is cleaved at the amino-terminal pseudosubstrate by the endoproteinase Arg-C. In marked contrast to mature (phosphorylated) enzyme, proteolysis occurs in the absence of lipid activators, revealing that precursor protein kinase C has its pseudosubstrate sequence removed constitutively. Additionally, we show that PDK-1 is unable to phosphorylate protein kinase C when the active site is sterically blocked by a peptide substrate. Neither can mature enzyme be dephosphorylated when the active site is blocked by binding either the pseudosubstrate sequence or a heterologous substrate. Thus, the accessibility of the activation loop to both phosphorylation and dephosphorylation requires an exposed pseudosubstrate. In summary, newly synthesized protein kinase C adopts a conformation in which its pseudosubstrate sequence is removed from the active site, rendering the activation loop accessible to phosphorylation by PDK-1. Phosphorylation serves as a conformational switch to position the pseudosubstrate so that it blocks the active site, a conformation that is maintained until stimulus-dependent membrane binding releases it, thus activating the enzyme.

Sphingosine is a novel activator of 3-phosphoinositide-dependent kinase 1.

3-Phosphoinositide-dependent kinase 1 (PDK1) has previously been shown to phosphorylate the activation loop of several AGC kinase family members. In this study, we show that p21-activated kinase 1, the activity of which is regulated by the GTP-bound form of Cdc42 and Rac and by sphingosine, is phosphorylated by PDK1. Phosphorylation of p21-activated kinase 1 by PDK1 occurred only in the presence of sphingosine, which increased PDK1 autophosphorylation 25-fold. Sphingosine increased PDK1 autophosphorylation in a concentration-dependent manner and significantly increased phosphate incorporation into known PDK1 substrates. Studies on the lipid requirement for PDK1 activation found that both sphingosine isoforms and stearylamine also increased PDK1 autophosphorylation. However, C(10)-sphingosine, octylamine, and stearic acid were unable to increase PDK1 autophosphorylation, indicating that both a positive charge and a lipid tail containing at least a C(10)-carbon backbone were required for PDK1 activation. Three PDK1 autophosphorylation sites were identified after stimulation with sphingosine in a serine-rich region located between the kinase domain and the pleckstrin homology domain using two-dimensional phosphopeptide maps and matrix assisted laser desorption/ionization mass spectroscopy. Increased phosphorylation of endogenous Akt at threonine 308 was observed in COS-7 cells expressing wild type PDK1, but not catalytically inactive PDK1, when cellular sphingosine levels were elevated by treatment with sphingomyelinase. Sphingosine thus appears to be a true PDK1 activator.

Regulation of conventional protein kinase C isozymes by phosphoinositide-dependent kinase 1 (PDK-1).

BACKGROUND: Phosphorylation critically regulates the catalytic function of most members of the protein kinase superfamily. One such member, protein kinase C (PKC), contains two phosphorylation switches: a site on the activation loop that is phosphorylated by another kinase, and two autophosphorylation sites in the carboxyl terminus. For conventional PKC isozymes, the mature enzyme, which is present in the detergent-soluble fraction of cells, is quantitatively phosphorylated at the carboxy-terminal sites but only partially phosphorylated on the activation loop. RESULTS: This study identifies the recently discovered phosphoinositide-dependent kinase 1, PDK-1, as a regulator of the activation loop of conventional PKC isozymes. First, studies in vivo revealed that PDK-1 controls the amount of mature (carboxy-terminally phosphorylated) conventional PKC. More specifically, co-expression of the conventional PKC isoform PKC betaII with a catalytically inactive form of PDK-1 in COS-7 cells resulted in both the accumulation of non-phosphorylated PKC and a corresponding decrease in PKC activity. Second, studies in vitro using purified proteins established that PDK-1 specifically phosphorylates the activation loop of PKC alpha and betaII. The phosphorylation of the mature PKC enzyme did not modulate its basal activity or its maximal cofactor-dependent activity. Rather, the phosphorylation of non-phosphorylated enzyme by PDK-1 triggered carboxy-terminal phosphorylation of PKC, thus providing the first step in the generation of catalytically competent (mature) enzyme. CONCLUSIONS: We have shown that PDK-1 controls the phosphorylation of conventional PKC isozymes in vivo. Studies performed in vitro establish that PDK-1 directly phosphorylates PKC on the activation loop, thereby allowing carboxy-terminal phosphorylation of PKC. These data suggest that phosphorylation of the activation loop by PDK-1 provides the first step in the processing of conventional PKC isozymes by phosphorylation.

Inhibition of Raf-1 signaling by a monoclonal antibody, which interferes with Raf-1 activation and with Mek substrate binding.

Raf-1 is a serine/threonine specific kinase that integrates signaling by a large number of mitogens to elicit a transcriptional response in the nucleus. Activated Raf-1 phosphorylates and activates MAPK/ERK kinase Mek), thus initiating the Mek--> MAP kinase cascade, which ultimately results in the phosphorylation and activation of transcription factors by MAP kinase. Here we have characterized the mechanism by which monoclonal antibody URP26K, which binds to an epitope in the Raf-1 kinase domain, inhibits intracellular signal transduction. This antibody preferentially immunoprecipitated the underphosphorylated, non-activated form of Raf-1 from quiescent cells. Baculovirus-expressed Raf-1 immunoprecipitated with URP26K was largely refractory to phosphorylation and activation mediated by protein kinase C (PKC)alpha or the tyrosine kinase Lck. In addition, URP26K reduced the binding of Raf-1 to its substrate Mek in vitro, but did not disturb the association of Raf-1 with Ras. Microinjection of URP26K into Rat-1 cells blocked DNA synthesis initiated by serum, insulin and various purified growth factors, but it did not block DNA synthesis initiated by v-ras. Microinjected URP26K also impaired the expression of stably transfected beta-galactosidase reporter genes regulated by minimal promoter elements. These results demonstrate, (i) that the URP26K monoclonal antibody inhibits Raf-1 by preventing activating Raf-1 phosphorylation and/or association with its substrate Mek, (ii) that inhibition of Raf-1 by URP26K does not interfere with Ras-induced DNA synthesis. In contrast to dominant negative Raf-1 mutants, which also block Ras signaling by binding to the Ras effector domain, antibody mediated Raf-1 inhibition thus reveals a branchpoint of mitogenic signaling at the level of Ras.

Hand sensibility of healthy older people.

OBJECTIVE: To develop normative data for four hand sensibility modalities in older subjects. DESIGN: Cross-sectional. SETTING AND PARTICIPANTS: Three hundred and sixty community-dwelling subjects of both sexes, aged 60 to 94, randomly selected from the electoral list of the city of Sherbrooke, Quebec, Canada. MEASUREMENTS: Touch/pressure threshold (Semmes-Weinstein monofilaments), static and moving two-point discrimination (Mackinnon-Dellon Disk-Criminator), tactile recognition (Modified Pick-up test), and thumb kinesthesia. RESULTS: A reduction with age was found in the performance of the study subjects, with the exception of the kinesthesia test. The values obtained in this study are clearly lower than the norms proposed for adults, underlining the importance of using reference values developed for the target clientele. CONCLUSION: The norms will help clinicians to differentiate better between normal and pathological changes in sensibility with age.

Protein kinase C is regulated in vivo by three functionally distinct phosphorylations.

BACKGROUND: Protein kinase Cs are a family of enzymes that transduce the plethora of signals promoting lipid hydrolysis. Here, we show that protein kinase C must first be processed by three distinct phosphorylations before it is competent to respond to second messengers. RESULTS: We have identified the positions and functions of the in vivo phosphorylation sites of protein kinase C by mass spectrometry and peptide sequencing of native and phosphatase-treated kinase from the detergent-soluble fraction of cells. Specifically, the threonine at position 500 (T500) on the activation loop, and T641 and S660 on the carboxyl terminus of protein kinase C beta II are phosphorylated in vivo. T500 and S660 are selectively dephosphorylated in vitro by protein phosphatase 2A to yield an enzyme that is still capable of lipid-dependent activation, whereas all three residues are dephosphorylated by protein phosphatase 1 to yield an inactive enzyme. Biochemical analysis reveals that protein kinase C autophosphorylates on S660, that autophosphorylation on S660 follows T641 autophosphorylation, that autophosphorylation on S660 is accompanied by the release of protein kinase C into the cytosol, and that T500 is not an autophosphorylation site. CONCLUSIONS: Structural and biochemical analyses of native and phosphatase-treated protein kinase C indicate that protein kinase C is processed by three phosphorylations. Firstly, trans-phosphorylation on the activation loop (T500) renders it catalytically competent to autophosphorylate. Secondly, a subsequent autophosphorylation on the carboxyl terminus (T641) maintains catalytic competence. Thirdly, a second autophosphorylation on the carboxyl terminus (S660) regulates the enzyme's subcellular localization. The conservation of each of these residues (or an acidic residue) in conventional, novel and atypical protein kinase Cs underscores the essential role for each in regulating the protein kinase C family.

Upper extremity performance test for the elderly (TEMPA): normative data and correlates with sensorimotor parameters. Test d'Evaluation des Membres Supérieurs de Personnes Agées.

OBJECTIVES: Objectives of this study were to develop normative data for the Test d'Evaluation des Membres Supérieurs de Personnes Agées (TEMPA) and determine its relation to upper extremity sensorimotor parameters such as fine and gross dexterity, coordination, strength, endurance, range of motion, and several types of sensibility. DESIGN: Cross-sectional study. SETTING: Community-dwelling subjects. PARTICIPANTS: Three hundred sixty healthy subjects randomly recruited by age and sex strata (60 to 69, 70 to 79, and 80 or older). MAIN OUTCOME MEASURES: Length of execution of the tasks in the TEMPA. RESULTS: Normative data are reported by gender and age group. The time taken to execute the tasks increased significantly with age. The women were faster on the tasks requiring a higher degree of fine dexterity, whereas the task requiring a lesser degree of fine dexterity and sensibility and more grip strength was accomplished faster by the men. Subjects who were more active and described themselves as being in excellent or good health performed better. CONCLUSION: The norms will help clinicians differentiate better between normal and pathological aging in upper extremity performance.

Comparison of the Jamar dynamometer and the Martin vigorimeter for grip strength measurements in a healthy elderly population.

Grip strength is considered to be a good indicator of upper limb strength. The Jamar dynamometer and the Martin vigorimeter are two instruments frequently used to assess grip strength in clinical and research settings. The purpose of this study was to compare these instruments for assessing grip strength in 360 people aged 60 to 94 years, randomly selected from the electoral list. Anthropometric data were also collected. Data analyses were done using the maximum value on 3 trials with each instrument. Although the Martin vigorimeter is a pressure measure implying a dynamic movement as opposed to the static strength measure of the Jamar dynamometer, results indicate a very high correlation between the two measures. Grip strength measured by the Jamar dynamometer is even more dependent on hand anthropometry than measurements with the Martin vigorimeter.

The Purdue Pegboard Test: normative data for people aged 60 and over.

Manual dexterity is frequently evaluated in rehabilitation services to estimate hand function. Several tests have been developed for this purpose, including the Purdue Pegboard, which measures fine manual dexterity. The goals of the study were to verify the test-retest reliability with subjects aged 60 and over without upper limb impairment, and to develop normative data based on a random sample of healthy older community-living individuals. The results show that the test-retest reliability is good (intra-class correlation coefficients from 0.66 to 0.90, depending on the subtest). Norms are presented to help clinicians involved in rehabilitation services to better differentiate real dexterity deficits from those that may be attributed to normal ageing.

Normative data for grip strength of elderly men and women.

OBJECTIVES: Grip strength is an important prerequisite for good performance of the upper limb, hence it is important to evaluate it correctly. However, one of the main difficulties in evaluating the grip strength of elderly patients is the absence of valid norms. Therefore, the objective of this study was to develop normative data for maximum grip strength of persons aged 60 years and older. METHOD: The grip strength of 360 subjects aged 60 years and older, randomly recruited by age and gender strata, was evaluated with the Jamar dynamometer and the Martin vigorimeter according to the protocol of the American Society of Hand Therapists. RESULTS: Grip strength diminishes curvilinearly with age, and men are consistently stronger than women. The data are presented by the means, standard deviations, and range, and as predictive equations obtained by regression analysis. In addition to age and gender, hand circumference and body height proved to be the best indicators of grip strength for this population of elderly subjects. CONCLUSION: The random recruitment of subjects, the high participation rate in the study, and the comparability of the subjects who agreed to participate and those who refused give this study the high external validity that is essential to any norm study. The predictive equations will help occupational therapists to better estimate the expected grip strength of elderly patients than they could if using only age and gender.

Upper-extremity motor co-ordination of healthy elderly people.

Motor co-ordination is an important prerequisite to adequate upper-extremity performance. With the ageing of the population, more and more elderly people are at risk of acquiring upper-extremity motor inco-ordination following sensorimotor deficit. The main objective of the study was to develop normative data on upper-extremity motor co-ordination for elderly people. Three hundred and sixty subjects aged 60 and over were randomly selected and evaluated with the Finger-Nose Test. The results revealed a linear decline in the performance of this test with age. Younger, more active and subjectively healthier subjects presented better motor co-ordination. Some differences were found between sexes and sides. The normative data will help clinicians to identify pathological reduction in motor co-ordination in an elderly population.

In vivo regulation of protein kinase C by trans-phosphorylation followed by autophosphorylation.

Dephosphorylation by the catalytic subunits of protein phosphatases 1 (CS1) and 2A (CS2) reveals that mature protein kinase C is phosphorylated at two distinct sites. Treatment of protein kinase C beta II with CS1 causes a significant increase in the protein's electrophoretic mobility (approximately 4 kDa) and a coincident loss in catalytic activity. The CS1-dephosphorylated enzyme cannot autophosphorylate or be phosphorylated by mature protein kinase C, indicating that a different kinase catalyzes the phosphorylation at this site. The loss of activity is consistent with dephosphorylation on protein kinase C's activation loop (Orr, J. W., and Newton, A. C., (1994) J. Biol. Chem. 269, 27715-27718). Treatment with CS2 results in a smaller shift in electrophoretic mobility (approximately 2 kDa) and no loss in catalytic activity. Furthermore, the CS2-dephosphorylated form can autophosphorylate and thus regain the electrophoretic mobility of mature enzyme, consistent with dephosphorylation at protein kinase C's carboxyl-terminal autophosphorylation site, which is modified in vivo (Flint, A. J., Paladini, R. D., and Koshland, D. E., Jr. (1990) Science 249, 408-411). In summary, two phosphorylations process protein kinase C to generate the mature form: a transphosphorylation that renders the kinase catalytically competent and an autophosphorylation that may be important for the subcellular localization of the enzyme.

Validation of the Box and Block Test as a measure of dexterity of elderly people: reliability, validity, and norms studies.

Manual dexterity is a skill frequently evaluated in rehabilitation to estimate hand function. Several tests have been developed for this purpose, including the Box and Block Test (BBT) that measures gross manual dexterity. The goal of the present study was to verify the test-retest reliability and construct validity of the BBT with subjects aged 60 and over with upper limb impairment. The second objective of this research was to develop normative data based on a random sample of healthy elderly community-living individuals. The results show that the test-retest reliability is high (intraclass correlations coefficients of 0.89 to 0.97) and the validity of the test is shown by significant correlations between the BBT, an upper limb performance measurement and a functional independence measurement. The norms will help rehabilitation clinicians to differentiate better between real difficulties and those that may be attributed to normal aging.

Principal components analysis of an evaluation of the hemiplegic subject based on the Bobath approach.

An evaluation based on the Bobath approach to treatment has previously been developed and partially validated. The purpose of the present study was to verify the content validity of this evaluation with the use of a statistical approach known as principal components analysis. Thirty-eight hemiplegic subjects participated in the study. Analysis of the scores on each of six parameters (sensorium, active movements, muscle tone, reflex activity, postural reactions, and pain) was evaluated on three occasions across a 2-month period. Each time this produced three factors that contained 70% of the variation in the data set. The first component mainly reflected variations in mobility, the second mainly variations in muscle tone, and the third mainly variations in sensorium and pain. The results of such exploratory analysis highlight the fact that some of the parameters are not only important but also interrelated. These results seem to partially support the conceptual framework substantiating the Bobath approach to treatment.

An evaluation of the hemiplegic patient based on the Bobath approach: a reliability study.

The intra- and inter-rater reliability of a motor function evaluation of stroke patients, based on the Bobath approach, was studied. The intraclass correlation coefficient (ICC) was used to determine the degree of agreement between repeated measurements on the same patient taken by the same rater and between measurements taken by three raters on the same patient. In the intra-rater study, each of 19 patients was evaluated in three different sessions by one of 19 raters. In the inter-rater study 18 patients were each evaluated by three different raters. The intra-rater data were highly reliable, with ICCs of 0.95 and 0.97 for the upper and lower limbs respectively. For the inter-rater study, the ICCs were 0.79 and 0.77 for the upper and lower limbs respectively. It can therefore be concluded that this instrument, previously demonstrated to quantify patient progress, is also reliable both in intra- and inter-rater dimensions.

Motor function and activities of daily living assessments: a study of three tests for persons with hemiplegia.

The relationship between upper extremity motor function and independence in basic activities of daily living in subjects with hemiplegia was explored. The Barthel Index (Mahoney & Barthel, 1965) and the Fugl-Meyer Test (Fugl-Meyer, Jääskö, Leyman, Olsson, & Steglind, 1975) were selected as the standard instruments for the evaluation of activities of daily living and upper extremity motor function, respectively, because their validity and reliability have been demonstrated many times. The Functional Test for the Hemiplegic/Paretic Upper Extremity (Wilson, Baker, & Craddock, 1984a, 1984b) was also used for the evaluation of upper extremity motor function. The results obtained in 18 subjects with hemiplegia indicate that the scores on the Barthel Index are poorly correlated with both the Fugl-Meyer Test and the Functional Test for the Hemiplegic/Paretic Upper Extremity scores. It is suggested that variables other than motor function, such as the learning of compensatory techniques and perceptual-cognitive status, are responsible for this discrepancy because they can influence activities of daily living performance in persons with hemiplegia. The high correlation between the scores on the Fugl-Meyer Test and the Functional Test for the Hemiplegic/Paretic Upper Extremity indicates that either test may be used for the assessment of upper extremity motor function.

Clinical significance of the V-shaped space in the subluxed shoulder of hemiplegics.

Recently, it has been proposed that shoulder subluxation in hemiplegia is accompanied by 1) the appearance of a V-shaped articular configuration occurring between the humeral head and glenoid fossa and 2) the presence of chronic pain. The main purpose of this study was to investigate the validity of these statements. We evaluated 40 hemiplegic subjects over 3 months. Radiographs of the affected and nonaffected shoulders were taken at both a frontal plane (0 degree) and a 45 degree incidence. From these patients, subluxed (n = 19) and nonsubluxed (n = 21) groups were formed. Pain was evaluated using the Present Pain Intensity index of the McGill Pain Questionnaire. On these x-ray films, measurements were taken of the V-shaped space, abduction of the arm, and rotation of the scapula. The statistical analysis (analysis of variance for repeated measures) contrasted the results obtained from the nonaffected side with those from the affected side over the 3 months studied. At the 45 degree angle, which better exposes the articular configuration of the shoulder, the difference in the V angle between the affected and nonaffected shoulders was significant for the subluxed group (p less than 0.01), indicating that such a V-shaped space can be identified. The measures taken also indicate that a downward subluxation of the humeral head occurs relative to the scapula without any systematic abduction of the humerus or downward rotation of the scapula. None of the results obtained from the frontal plane x-ray films was significant. Finally, no significant relation was found between subluxation and shoulder pain.