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PubMed1980

[The function W = (a--b e-ct)n, a generalization of the classical growth functions (author's transl)].

The generalization of Bertalanffy's function of length and mass growth and the extension of the Gompertz function to 4 parameters as exercised by the author (Sager 1979 b, a) leads to the equation W = (a--b e-ct)n with positive values of n, and b in the first case and negative ones for n and b in the second case. It is shown that with the range of values for n the above expression comprises all classical functions of organic growth, namely the logistic or Verhulst function (1838), the Mitscherlich function (1919), and the Pütter-Bertalanffy functions (1920, 1934) of length and mass development. Moreover, the limiting case n leads to +/- infinity leads to the Gompertz-function (1825), as can be verified by the increase ansatz of the universal expression. Beside graphs examples are given showing the evaluation of the parameters a, b, c and n in the case of free choice as well as c, d and n for the transformed notation W = W0 [(1--de-ct)/(1--d)]n with a given initial value W0 leaving three parameters for choice.

Animals↗

PubMed1994

Mechanism involved in the systemic suppression of antigen-presenting cell function by UV irradiation. Keratinocyte-derived IL-10 modulates antigen-presenting cell function of splenic adherent cells.

Exposure to UV radiation suppresses tumor rejection and delayed-in-time hypersensitivity reactions and depresses splenic APC function. Because almost all of the UV radiation is absorbed in the upper layers of the skin, it appears unlikely the direct irradiation of APC can account for the impaired ability of splenic adherent cells to present Ag after total-body UV exposure. Because UV-irradiated keratinocytes release IL-10, and in light of the well-documented effects of IL-10 on Ag presentation, we tested the hypothesis that keratinocyte-derived IL-10 is responsible for the systemic impairment of APC function following UV exposure. Injecting supernatants from UV-irradiated keratinocytes suppressed the ability of splenic adherent cells to present Ag. Treating the supernatants with anti-IL-10 mAb neutralized the suppressive effect. Similarly, when splenic adherent cells were isolated from mice exposed to UV radiation, APC function was suppressed. Injecting the UV-irradiated animals with anti-IL-10 restored APC function. In addition, spleen cells from UV-irradiated mice did not efficiently present Ag to Th1 clones, and injecting anti-IL-10 after UV exposure restored APC function. The reverse was observed when spleen cells from UV-irradiated mice were used to present Ag to Th2 clones; in which case, UV exposure enhances APC function, and anti-IL-10 reverses this effect. These findings suggest that UV-induced, keratinocyte-derived IL-10 can modulate splenic APC function.

Animals↗

PubMed1996

Development and validation of a rheumatoid hand functional disability scale that assesses functional handicap.

OBJECTIVE: To construct a functional disability scale for the rheumatoid hand and to determine if this scale also assesses functional handicap. METHODS: Outpatients and inpatients with rheumatoid arthritis (RA) according to the ACR criteria answered a set of questions on their daily hand activities. Intrarater and interrater reliability were examined. Criterion referenced validity, and convergent and divergent validities were investigated. Factor analysis followed by varimax rotation was performed. Spearman's (rs) correlation coefficients between 2 quantitative variables were examined. The level of significance was p < 0.05. RESULTS: 96 patients with RA were recruited. The provisional scale had 41 questions. The elimination process left 18 hand activity questions with 6 levels of answers. The intrarater and interrater reliabilities of the scale were 0.97 and 0.96, respectively. Correlation of the scale's total score with visual analog scale (VAS) measure of functional handicap (rs = 0.78) showed good criterion referenced validity. The scale had good convergence with Revel's Functional Index (rs = 0.91) and a moderate relation to the Hand Functional Index (HFI) (rs = 0.58). The scale had a moderate, fair, or no relation to age, morning stiffness, pain measures, and hand swelling. The scale had 3 main factors by factor analysis. An English translation of the scale was validated. CONCLUSION: We have developed a practical functional disability scale for rheumatoid hands that also assesses functional handicap. It has 18 hand activity questions and has been validated in a French population.

Adolescent↗

PubMed1976

Renal function in experimental chronic hydronephrosis. III. Glomerular and tubular functions in relation to renal pelvic volume.

Studies of renal function comprising determination of exogenous creatinine clearance, urinary osmolality and TmG were performed on 23 dogs, for each kidney separately, after hydronephrosis with partial ureteric obstruction had been produced by ligation of one ureter over an indwelling catheter. A method for determining the volume of the hydronephrotic renal pelvis was developed and the degree of functional reduction was correlated to the degree of pelvic dilatation. In 11 cases the renal blood flow was determined by direct measurement. Statistically significant reductions of the glomerular and tubular functions were noted on the hydronephrotic side. TmG and the urinary osmolality showed the greatest percentual decreases and the TmG/GFR ratio the smallest. The decrease in this ratio was due to greater deterioration of tubular than of glomerular function. The renal blood flow was reduced on the hydronephrotic side in comparison with the intact side, but seemed relatively less affected than the glomerular and tubular functions. Compensation by the intact kidney resulted in masking of the deterioration on the hydronephrotic side; thus for the whole material the mean GFR and urinary osmolality for the two kidneys together remained essentially unchanged. No statistically significant correlation between the degree of functional reduction and the degree of pelvic dilatation was found. Such a correlation could therefore not be used in the individual case as an indication of the functional capacity of a kidney.

Animals↗

PubMed1988

[Loss of renal functional reserve following kidney transplantation and in patients with advanced disorders of liver function].

Renal functional reserve capacity was evaluated in healthy controls, kidney transplant recipients and patients with impaired liver function by simultaneous measurements of periodic clearances of inulin, PAH and creatinine every 30 minutes before, during and after infusion of an amino acid (AA) solution. During AA infusion glomerular filtration rate rose in 10 healthy controls to about 35% above basal values (inulin clearance from 107 +/- 6 to 144 +/- 7 ml/min, p less than or equal to 0.0005), renal plasma flow increased by 27% (PAH clearance from 530 +/- 25 to 675 +/- 40 ml/min, p less than or equal to 0.002). 8 renal transplant recipients with good and stable renal function (creatinine clearance above 65 ml/min) showed no rise in GFR and RPF, as did 10 patients with severe impairment of liver function and normal basal kidney function (creatinine clearance above 100 ml/min). The lack of renal functional reserve in kidney transplant recipients might indicate a hyperfiltration of the transplanted kidney. This could affect the longtime prognosis of these patients. The liver seems to play a role in the mediation of the amino acid-induced rise of GFR, supporting the hypothesis of a putative liver hormone regulating GFR after protein ingestion or AA infusion.

Adult↗

PubMed2000

The reorganization of sensorimotor function in children after hemispherectomy. A functional MRI and somatosensory evoked potential study.

Children who have suffered extensive unilateral brain injury early in life may show a remarkable degree of residual sensorimotor function. It is generally believed that this reflects the high capacity of the immature brain for cerebral reorganization. In this study, we investigated 17 patients who had undergone hemispherectomy for relief from seizures; eight of the patients had congenital brain damage and nine had sustained their initial insult at the age of 1 year or older. Sensorimotor functions of the hand were investigated using functional MRI (fMRI) during a passive movement task, somatosensory evoked potentials (SEPs) arising from electrical and vibration stimulation, and behavioural tests including grip strength, double simultaneous stimulation and joint position sense. On fMRI, two of the eight patients studied with this technique (one with congenital damage and one with damage acquired at the age of 3 years) showed activation in the sensorimotor cortex of the remaining hemisphere with passive movement of the hemiplegic hand. The location of the ipsilateral brain activation was similar to that found on movement of the normal contralateral hand, although the latter was greater in spatial extent. In one of these patients, a greater role was demonstrated for the ipsilateral secondary sensorimotor area (compared with the ipsilateral primary sensorimotor area) for movement of the hemiplegic hand than for movement of the normal hand. Median nerve stimulation of the hemiplegic hand showed reproducible early-latency ipsilateral SEP components in the remaining sensorimotor cortex in 10 of the 17 patients (five with congenital and five with acquired disease). Five of the patients who demonstrated ipsilateral electrical SEPs also showed ipsilateral vibration SEPs (two with congenital and three with acquired disease). The behavioural tests revealed residual sensorimotor function in 14 of the patients; however, not all of the patients who exhibited ipsilateral SEP or fMRI responses had residual sensorimotor function in the hemiplegic hand. Ipsilateral sensorimotor responses were demonstrated both in patients with congenital disease and those with acquired disease, suggesting that factors additional to aetiology and age at injury may influence the degree of residual sensorimotor function and cerebral reorganization.

Adolescent↗

PubMed1994

The DEFIANT study of left ventricular function and exercise performance after acute myocardial infarction. Doppler Flow and Echocardiology in Functional Cardiac Insufficiency: Assessment of Nisoldipine Therapy Study Group.

The DEFIANT-I study (Doppler Flow and Echocardiography in Functional cardiac Insufficiency: Assessment of Nisoldipine Therapy) was a multicenter, multinational double-blind randomized study of the effects of the new calcium channel blocking drug nisoldipine on left ventricular (LV) size and function after acute myocardial infarction. Randomization to placebo or to long-acting nisoldipine core coat (20 mg once daily) was performed in 135 eligible patients with mild to moderate systolic LV dysfunction (LV ejection fraction < or = 50%) 20 days (range 7-35) after infarction, with serial clinical, echocardiographic, and Doppler cardiographic measurements during a 4 week follow-up period. At the end of the follow-up period, exercise capacity was determined by bicycle ergometry. Nisoldipine improved indices of diastolic LV function. Early diastolic transmitral blood flow velocity increased, with an increase in peak E wave of 0.06 m/sec (95% confidence intervals [CI], 0.01, 0.11) and an increase in time velocity integral of 1.2 cm (95% CI, 0.16, 2.27). Isovolumic relaxation time was reduced by 14.7 msec (95% CI, -22.5, -6.9), a change not explained by the very small (and not significant) changes in systemic arterial pressure, heart rate, or cardiac output. There was no change in systolic and diastolic LV volume, nor in LV ejection fraction. Exercise capacity was greater by 12 watts (95% CI, 0.8, 23.3) in patients receiving nisoldipine, while the incidence of > or = 1 mm ST-segment depression (relative occurrence 0.54, 95% CI, 0.30-0.97) and the incidence of angina pectoris (relative occurrence 0.67, 95% CI, 0.42-1.08) during exercise testing tended to be lower in this group. Although the relations were not exact, peak exercise workload 7 weeks after infarction correlated with resting measurements of diastolic LV function. Exercise workload was inversely related to peak late diastolic transmitral blood flow velocity (A wave, slope, -86.6; 95% CI, -120.9, -52.2) and directly to the E/A ratio (slope, 20.5, 95% CI, 6.0, 35.1). The relations between exercise workload and peak late diastolic flow velocity remained significant after correction for age, sex, resting heart rate, and usage of beta-blocking drugs or nisoldipine. Exercise capacity was not related to measurements of systolic LV function (LV end-diastolic and end-systolic volume, LV ejection fraction, stroke volume, cardiac index). In summary, the calcium channel blocker nisoldipine improved measurements of diastolic LV function in patients recovering from acute myocardial infarction. Exercise capacity was higher in patients receiving the drug, and there was less exercise induced ischemia.(ABSTRACT TRUNCATED AT 400 WORDS)

Double-Blind Method↗

PubMed2005

Duodenum preservation in pancreatic head resection to maintain pancreatic exocrine function (determined by pancreatic function diagnostant test and cholecystokinin secretion).

BACKGROUND/PURPOSE: Organ-preserving surgery, such as pylorus-preserving pancreatoduodenectomy (PPPD), duodenum-preserving pancreatic head resection (DPPHR), or medial pancreatectomy (MP), is one of the recent advances in pancreatic surgery. There was a previous report that preservation of the duodenum maintained pancreatic function. However, concerning the resected pancreas, patients were divided into two groups; one group included pancreatic head resections such as Whipple, PPPD, and complete DPPHR, and the other group included MP that removed only the pancreatic neck and preserved the pancreatic head and distal pancreas. The present study was designed to clarify the significance of duodenum preservation, in comparison with duodenum removal, in patients with pancreatic head resection, in terms of pancreatic function, determined by a pancreatic function diagnostant (PFD) test and cholecystokinin (CCK) secretion. METHODS: The subjects were 61 patients (10 with Whipple, 41 with PPPD, and 10 with complete DPPHR). PFD tests and postprandial plasma CCK secretion were used for evaluation. RESULTS: There was a significant difference between pre- and postoperative PFD values in the patients who received Whipple or PPPD; however, there was no difference in those who had complete DPPHR. Concerning the postoperative PFD value, complete DPPHR was superior to Whipple and PPPD. Regarding postprandial CCK secretion, the pre- and postoperative values were significantly different in the patients with Whipple or PPPD, but there was no difference in those with complete DPPHR. Comparing the three kinds of operations, complete DPPHR was superior to the other two procedures in its maintenance of pancreatic function. There was the significant correlation between CCK and PFD in our patients in the Spearman Rank Correlation (P < 0.0029) and Fisher's r to z (P < 0.0058). CONCLUSIONS: When pre- and postoperative pancreatic exocrine function and postprandial CCK secretion were measured in patients with pancreatic head resection, it was found that preservation of the entire duodenum was an important factor for maintaining pancreatic function.

Cholecystokinin↗

PubMed1995

Differential recovery of volitional motor function, lateralized cognitive function, dopamine agonist-induced rotation and dopaminergic parameters in monkeys made hemi-parkinsonian by intracarotid MPTP infusion.

There is still controversy regarding the frequency and extent of spontaneous functional recovery in primate models of parkinsonism, perhaps in part stemming from the variety of ways in which recovery has been assessed. The present study examined functional recovery in monkeys made unilaterally parkinsonian by intracarotid infusion of MPTP. Monkeys were evaluated prior to lesioning and for at least 1 year after lesioning on a battery of tests including a rating of spontaneous behaviors, a learned reaction time/movement time task, tests of lateralized neglect or inattention (i.e. lateralized reward retrieval task, extinction with double simultaneous stimulation, and response to a target moving from one hemispace to the other), and rotational asymmetry in response to a dopamine agonist. Some animals also received 6-[18F]Fluoro-L-Dopa (F-DOPA) position emission tomography (PET) scans before MPTP, when symptomatic, and when showing signs of functional recovery. These animals were sacrificed for post mortem neurochemical assessment following the last PET scan. Results showed that estimates of functional recovery in hemi-parkinsonian monkeys may depend upon the behavioral assay used. Even in behavioral tasks that were sensitive to recovery effects, the degree of functional recovery shown by an animal on one such task did not predict recovery on another. This may in part be due to the inherent difficulty in designing behavioral tests to assess basal ganglia functioning, when there is no consensus concerning which aspects of behavior the normal basal ganglia actually control.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed2006

Hemodynamic change in transmitral gradient during Valsalva maneuver and its relation with left atrial function, functional capacity, and pulmonary artery pressure in patients with mitral stenosis in sinus rhythm.

BACKGROUND: The hemodynamic factors contributing to the clinical symptomatology in patients with mitral stenosis (MS) have been under investigation. The objective of this study was to evaluate the use of the Valsalva maneuver in patients with MS and whether there is an association between the degree of the hemodynamic changes in transmitral gradient (TG) in response to Valsalva maneuver and functional status, systolic pulmonary artery pressure, and left atrial function in patients with MS in sinus rhythm. METHODS: The study prospectively evaluated 42 patients (37 female, mean age 40 +/- 10 years) with a diagnosis of pure MS in sinus rhythm. Patients were divided into 3 groups according to their New York Heart Association (NYHA) functional class. In all, 12 patients were in NYHA functional class I, 17 patients in class II, and 13 patients in class III. TG, including the mitral peak, mean, and late filling gradients, were calculated by the modified Bernoulli equation at rest and during the strain phase of Valsalva maneuver. The percentage changes in all TG in response to Valsalva were calculated. Traditional echocardiographic parameters for atrial function were also measured. RESULTS: We found that, in patients who were more symptomatic according to NYHA classification, a reduction in TG in response to Valsalva maneuver was blunted and associated with higher systolic pulmonary artery pressure compared with those who were asymptomatic or had mild symptoms. Patients in NYHA class III decreased mitral mean pressure gradient by only 13.5%, significantly less (P < .001) than those in classes I (53.9%) and II (41.7%). However, despite the fact that left atrial ejection fraction was low in all patients, it was not associated with functional status in patients with MS. CONCLUSION: This study, for the first time, suggests that echocardiographically determined changes in TG in response to the Valsalva maneuver may provide an objective, noninvasive means of evaluating patients with MS.

Adaptation, Physiological↗

PubMed2003

Preserved verbal memory function in left medial temporal pathology involves reorganisation of function to right medial temporal lobe.

The left hippocampus and related structures mediate verbal memory function. The mechanism underlying preserved verbal memory function in patients with left hippocampal damage is unknown. Temporal lobe epilepsy, a common disease, is frequently the consequence of a characteristic hippocampal pathology termed hippocampal sclerosis, which may also affect the amygdala. In this setting, mapping the sites of memory function is a vital component of planning for surgical treatment for epilepsy. Using event-related functional magnetic resonance imaging, we studied 24 right-handed nonamnesic patients with left hippocampal sclerosis and 12 normal controls, performing a verbal encoding task. The patients were subdivided into two groups according to presence or absence of additional left amygdala pathology. Analysis of the data employed a two-level random-effects design, examining the main effects of subsequent memory in each group, as well as the differences between the groups. Additional effects of emotionality of the remembered words were also examined. Verbal memory encoding involved activation of left hippocampus in normals, but was associated with reorganisation to right hippocampus and parahippocampal gyrus in the patients. The additional presence of left amygdala sclerosis resulted in reorganisation for encoding of emotional verbal material to right amygdala. Retained verbal memory function in the presence of left medial temporal lobe pathology is mediated by recruitment of a parallel system in the right hemisphere consistent with adaptive functional reorganisation. The findings indicate a high degree of plasticity in medial temporal lobe structures.

Amygdala↗

PubMed2005

The functional neuroanatomy of classic delayed response tasks in humans and the limitations of cross-method convergence in prefrontal function.

Three classic delay tasks: spatial delayed response, delayed spatial alternation and delayed object-alternation are prototypical experimental paradigms for mapping the functional neuroanatomy of prefrontal cortex in animals. These tasks have been applied in human lesion studies, yet there have been very few studies investigating their functional neuroanatomy in healthy human subjects. We used functional magnetic resonance imaging to investigate the functional neuroanatomy of these classic paradigms (and a fourth: object delayed response) in a single sample of healthy human participants. Consistent with previous animal, human lesion, and functional neuroimaging studies, activity was observed in prefrontal and posterior parietal cortices across all three delay tasks. Task-specific activations, however, were not entirely consistent with predictions drawn from animal lesion studies. For example, delayed object-alternation activated dorsolateral prefrontal cortex, a region not generally implicated in animal lesion reports. Spatial delayed response, classically associated with the dorsolateral prefrontal cortex, did not activate this region; it rather activated posterior premotor cortices involved in response preparation, as did spatial alternation. All three tasks activated the frontopolar cortex, a region not considered crucial in animal research but associated with manipulation of internally generated information in recent human research. While cross-method convergence may be attained for lower level perceptual or motor tasks, the results of this study caution against the assumption that lesion-specific effects in animals generalize to human prefrontal cortex function.

Adult↗

PubMed1983

Criteria of functional operability in patients with bronchial carcinoma: preoperative assessment of risk and prediction of postoperative function.

In this prospective study of 433 patients undergoing surgery for bronchial carcinoma 3 main factors influencing the operative risk were identified: (1) extent of resection, (2) pulmonary function and (3) age. The 30-day mortality rate was 8.3% in the whole group which comprised a high percentage of patients over 70 years of age (27%) and with a disturbed pulmonary function (45%). The value of various functional criteria proposed in the extensive literature is assessed and compared with the results of the study in which the use of FEV1 and quantitative regional analysis by perfusion scanning and 'regions of interest' proved to be highly efficient, allowing, in addition, the prediction of postoperative lung function even in sleeve resections. A new formula for estimation of the additional loss of function in the early postoperative phase after lobectomies is proposed along with a flow sheet for routine preoperative evaluation of pulmonary function.

Age Factors↗

PubMed2005

Differential item functioning of the Functional Independence Measure in higher performing neurological patients.

OBJECTIVE: When comparing outcomes of the Functional Independence Measure (FIM ) between patient groups, item characteristics of the FIM should be consistent across groups. The purpose of this study was to compare item difficulty of the FIM in 3 patient groups with neurological disorders. SUBJECTS: Patients with stroke (n=295), multiple sclerosis (n=150), and traumatic brain injury (n=88). METHODS: FIM scores were administered in each group. The FIM consists of a motor domain (13 items) and a cognitive domain (5 items). Rasch rating scale analysis was performed to investigate differences in item difficulty (differential item functioning) between groups. RESULTS: Answering categories of the FIM items were reduced to 3 (from the original 7) because of disordered thresholds and low answering frequencies. Two items of the motor domain ("bladder" and "bowel") did not fit the Rasch model. For 7 out of the 11 fitting motor items, item difficulties were different between groups (i.e. showed differential item functioning). All cognitive items fitted the Rasch model, and 4 out of 5 cognitive items showed differential item functioning. CONCLUSION: Differential item functioning is present in several items of both the motor and cognitive domain of the FIM. Adjustments for differential item functioning may be required when FIMdata will be compared between groups or will be used in a pooled data analysis.

Activities of Daily Living↗

PubMed2005

Impairment of lung function, health status and functional capacity in patients with ANCA-associated vasculitis.

OBJECTIVE: To determine the effects of lung involvement on respiratory function in patients with ANCA-associated vasculitis and the relation to impaired health status. METHODS: Thirty patients with ANCA-associated vasculitis in remission (15 with lung involvement at diagnosis as determined by an abnormal chest X-ray) were examined. We measured lung function, skeletal muscle strength [quadriceps force (QF), respiratory muscle strength (Pi(max))], exercise capacity (VO(2) peak) using treadmill exercise tests, and health status using the Short Form 36 and St George's respiratory questionnaires. RESULTS: Exercise capacity was reduced compared with predicted values (58.2%, range 23-123%) and 18 patients showed functional aerobic impairment. Respiratory muscle function was reduced (72.1% predicted, range 20-108%) and was not related to lung involvement or steroid usage. Transfer factor correlated significantly with exercise capacity, suggesting inadequate delivery of oxygen to muscles. Nine patients had reduced transfer factor (seven with lung involvement). Patients with lung involvement had impaired gas transfer compared with those without lung involvement (96.9 +/- 6 vs 113.3 +/- 4.7% predicted, P = 0.04). However, there were significant abnormalities in other lung function parameters not related to previous lung involvement (eight patients had reduced forced expiratory volume in 1 s, and five patients had reduced residual volume). Twelve patients (five with previous lung involvement) had obstructive airways disease. Physical health status was impaired to a greater degree than mental health status across the whole group and was not related to lung involvement or original disease severity, but correlated with transfer factor. CONCLUSION: Patients with ANCA-associated disease may have significant lung function impairment irrespective of lung involvement at the time of diagnosis. Patients showed reduced respiratory muscle strength, health status and exercise capacity, which correlated with reduced transfer factor.

Adult↗

PubMed2006

Combined functional task practice and dynamic high intensity resistance training promotes recovery of upper-extremity motor function in post-stroke hemiparesis: a case study.

BACKGROUND AND PURPOSE: Weakness is a significant impairment in persons with post-stroke hemiparesis, yet traditional clinical perspectives caution against strengthening in neurological populations. Significant correlations between weakness and functional movement have been demonstrated, however, a clear relationship between increased strength and functional improvement has been elusive. This case study describes a combined program of dynamic, high-intensity resistance training and functional task practice for the upper-extremity in adult hemiparesis. CASE DESCRIPTION: The patient was a 65-year-old, right hand dominant woman who presented to the Neural Control of Movement Laboratory at the Palo Alto VA Rehabilitation Research and Development Center 16 weeks following clipping of an unruptured aneurysm with consequent dense right hemiparesis. She received 7 weeks of acute rehabilitation according to CARF guidelines (ie, at least 3 hours of two or more disciplines, 6 days per week). Her baseline research evaluation revealed significant upperextremity deficits at the ICF body structure/function level including: weakness, shoulder pain, mild resistance to passive movement, and need for moderate to maximal assistance in many activities of daily living including bathing and dressing. The Stroke Impact Scale score reporting her perspective indicated she had recovered from her stroke only 50%. The hybrid resistance training-functional task practice intervention, detailed in this report, was delivered 3 times per week for 6 weeks with each session lasting 75:00. OUTCOMES: The subject revealed marked improvements in isometric and dynamic force production in 5 key upper-extremity actions: elbow flexion, elbow extension, shoulder flexion, shoulder abduction, and shoulder external rotation. Strength gains were accompanied by increased EMG activation immediately postintervention and by a combination of increased activation and apparent hypertrophic effects at 6 month follow up. Marked improvements were noted in all clinical and functional measures and in an elbow trajectorytracking task which served as a surrogate measure of motor control. DISCUSSION: Improvements in strength and positive outcome effects at the physiological, clinical, and functional levels were observed in this subject following the experimental hybrid upper-extremity rehabilitation intervention described. Importantly, no deleterious effects were observed including exacerbation of spasticity or musculoskeletal compromise. Observations of improved EMG activation in this case study suggest that improvements in motor activation underlie these strength gains and can likely be attributed to working at a high intensity level.

Activities of Daily Living↗

PubMed2006

Platelet function analyzer (PFA)-100 closure time in the evaluation of platelet disorders and platelet function.

BACKGROUND: Closure time (CT), measured by platelet function analyzer (PFA-100) device, is now available to the clinical laboratory as a possible alternative or supplement to the bleeding time test. AIM: On behalf of the Platelet Physiology Subcommittee of the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis (ISTH-SSC), a working Group was formed to review and make recommendations on the use of the PFA-100 CT in the evaluation of platelet function within the clinical laboratory. METHODS: The Medline database was searched to review the published information on the PFA-100 CT in the evaluation of platelet disorders and platelet function. This information, and expert opinion, was used to prepare a report and generate consensus recommendations. RESULTS: Although the PFA-100 CT is abnormal in some forms of platelet disorders, the test does not have sufficient sensitivity or specificity to be used as a screening tool for platelet disorders. A role of the PFA-100 CT in therapeutic monitoring of platelet function remains to be established. CONCLUSIONS: The PFA-100 closure time should be considered optional in the evaluation of platelet disorders and function, and its use in therapeutic monitoring of platelet function is currently best restricted to research studies and prospective clinical trials.

Blood Platelet Disorders↗

PubMed2001

The infant lung function model: a mechanical analogue to test infant lung function equipment.

To facilitate international multicentre studies and quality control of infant pulmonary function measurements, the European Respiratory Society-American Thoracic Society (ERS-ATS) working group for infant lung function testing aims to develop specifications for standardized infant lung function equipment and software. However, a standardized test device is also needed to test whether existing infant lung function equipment is able to meet these requirements. The authors have built a "mechanical model baby" consisting of a linear pump which can reproduce prerecorded tidal flow waveforms with a precision of 0.5% (full stroke), enabling the simulation of tidal and forced flow patterns. This linear pump can be connected to a series of copper lung volumes (range 50-300 mL) with known time constants, so that lung volumes can be reproduced with a precision of +/-1% at frequencies 10-120bpm. Five airflow resistors were built using sinter material. When assessed using flows 0-300 mL.s(-1) all resistors showed a quasilinear pressure/ flow relationship, with slopes 1.0-5.6 kPa.L(-1).s. These resistances could be reproduced with a precision of +/-2.5%. The infant lung model can also be used to assess frequency responses of infant lung function equipment, since the pump is capable of delivering low amplitude volumes up to 20 Hz in a pseudorandom noise manner. In summary, based on error estimations, this infant lung model is able to test whether or not infant lung function equipment meets the requirements suggested by the European Respiratory Society-American Thoracic Society standardization group, that is: flow measurements within +/-2.5%, volume and resistance measurements within +/-5%, frequency response: magnitude attenuation <+/-10% and phase shift <+/-3 degrees at 10 Hz.

Airway Resistance↗