A Low Vision Reading Comprehension Test

The Low Vision Reading Comprehension Assessment (LVRCA) uses an 18-sentence cloze format in two equivalent forms to measure understanding of print reading by persons with macular degeneration. It requires nine minutes to administer and thus can be used in clinical settings. This article describes its development and a study of the reliability and validity of the LVRCA tested on 50 persons with macular degeneration.

The Efficacy of Comprehension Training and Reading Practice for Print Readers with Macular Loss

The objectives of the project reported here were to discover whether the rehabilitation of reading recognition allows comprehension of print for low vision individuals who were former readers and to develop and test training strategies for enhancing comprehension for those who do not achieve good comprehension.

Transient Elastohydrodynamic Lubrication Models for the Human Ankle Joint

An equivalent bearing was proposed to represent the normal human ankle joint. The geometry was based on measurements of dissected ankle joints and tissue properties were obtained from the work of previous investigators. Theoretical models were developed to estimate the cyclic variation in lubricant film thickness and coefficient of friction during repetitive activities such as walking. Solutions were obtained for various combinations of input parameters. For the conditions representing the walking cycle, film thicknesses of about 0.7 μm were calculated. Although this value was smaller than most previous measurements of the rms roughness of cartilage, it was not much smaller and suggested that transient elastohydrodynamic lubrication played a role in synovial joint lubrication. The possibility of full fluid film lubrication was supported only when a very high input viscosity was employed, based on values estimated from the previous experimental studies of the boosted lubrication mechanism. Also, an attempt was made to link the current findings to a published experimental study of whole joint lubrication.

A Study of the Role of Synovial Fluid and its Constituents in the Friction and Lubrication of Human Hip Joints

Human hip joints have been studied in a pendulum apparatus and a joint simulator to determine the lubrication mechanisms active in normal physiological activities. Various lubricants have been used to lubricate the hip joints including bovine and human synovial fluid, synovial fluid which has been digested with hyaluronidase or trypsin, silicone fluids of different viscosities, as well as synovial fluid and Ringer's solution which have had their viscosities increased by the addition of hyaluronic acid.

The results indicate that under continuous dynamic loading, fluid film lubrication seems to prevail while under static loading, mixed lubrication exists. Increasing the viscosity of the lubricant from very low values (i.e. from 10-3 Pa.s) leads to a reduction in friction, indicating mixed lubrication, until a value of about 0.050 Pa.s was achieved. Further increases seemed to indicate that fluid film lubrication was then present.

An Experimental Study of Friction and Lubrication in Hip Prostheses

McKee-Farrar, Charnley and Muller prostheses have been studied in a hip function simulator using a range of silicone fluids as lubricants. Frictional resistance was measured continuously while the joints were subjected to dynamic loading.

It was observed that the lubricant viscosity was very important to the mode of lubrication prevailing and that for viscosities in excess of 0.1 Pas, full fluid film lubrication was achieved. At viscosities which were less than this, mixed lubrication resulted

These results can be extrapolated to the clinical situation where it was found that after hip surgery for total joint replacement, the synovial fluid produced around the prosthesis had a viscosity which was less than 0.1 Pas, and therefore could not give the most advantageous lubrication in these joints in vivo.

Muscle Strengths and Musculoskeletal Geometry of the Upper Limb

A survey of past literature has shown that there is a lack of reliable data for use in prediction of joint forces in the upper limb although this is desirable when developing joint replacements. Upper limb geometry has been analysed, leading to muscle moment arm data at the wrist and elbow. The variation of these moment arms during elbow flexion has also been examined. Analysis of the dimensions of muscles has enabled their relative strengths to be predicted, based on their ‘physiological cross-sections’. When used in conjuction with published emg data, this information will enable elbow and wrist joint forces to be estimated more realistically than has previously been possible.

An Evaluation of the Ratio between the Tensions along the Quadriceps Tendon and the Patellar Ligament

An experiment was devised whereby physiological loads could be applied to the quadriceps tendon of cadaveric knee joints so that the ratio of tensions in the quadriceps tendon and the patellar ligament could be determined. On two knee joints, radiographs were taken before testing, so that the theoretical ratio of the tensions could be evaluated and compared with the experimental results. As the knee was flexed, the ratio of the tensions, frequently assumed to be unity, reduced by up to fifty per cent.

Forces in the Knee Joint Whilst Rising from Normal and Motorized Chairs

Knee joint forces were determined by kinesiological techniques using a high speed camera and force platforms so that a comparison could be made for rising from a normal chair without the aid of arms and with the aid of a motorized chair. For rising from a normal chair, the knee joint forces parallel to the long axis of the tibia at the point of contact between the tibia and femur, were found to be up to seven times body weight at about the time when the body left contact with the chair. Using a motorized chair the knee joint forces were reduced to less than body weight until normal standing was achieved.

Médecins Sans Frontières' Clinical Guidance mobile application: analysis of a new electronic health tool

Many health care workers lack access to clinical support tools in rural and resource-limited settings. To address this gap, the Médecins Sans Frontières (MSF) Clinical Guidelines manual was converted into a static mobile health reference application (app) entitled MSF Guidance. The app's utility and growth was examined, and within 6 months of its launch 150 countries had downloaded the app, with demonstrated retention among new and existing users. With over 3500 downloads and 36 000 sessions amounting to 250 000 screen views, MSF Guidance is a new mobile health platform with widely demonstrated utility, including potential use as an epidemiological tool, where clinical conditions investigated by app users were found to correlate with geographical outbreaks. These findings show that mobile apps can be used to disseminate health information effectively.

The youth report version of the Child and Adolescent Scale of Participation (CASP): assessment of psychometric properties and comparison with parent report

OBJECTIVE

The Child and Adolescent Scale of Participation (CASP) parent report is a brief and valid measure for use with children and youth with chronic conditions/disabilities that has been shown to have good coverage at the chapter level of the 'Activities and Participation' component of the International Classification of Functioning, Disability and Health. The purpose of this research was to assess the psychometric properties of a CASP youth self-report version, to further validate the parent report, and to compare parent and youth reports of youths' activity and participation.

METHODS

Baseline data from a longitudinal study examining predictors of changes in quality of life for youth with chronic conditions/disabilities were used. CASP data were collected on 409 youth aged 11-17 with various conditions/disabilities using youth and parent reports. Internal consistency and factor structure were examined for both versions using Cronbach's alpha and exploratory factor analyses. Inter-rater agreement and magnitude of differences between youth and parent report were evaluated using intraclass correlation coefficients and paired t-tests respectively. Gender, age and condition/disability group differences in youth report CASP scores were examined using independent t-tests or analyses of variance.

RESULTS

Strong internal consistency and internal structure validity was demonstrated for the CASP youth and parent report. The youth report factor structure was similar to the parent report in this and other studies. Youth reported their activity/participation to be significantly higher than did their parents. Significant differences in CASP scores were found among condition/disability groups.

CONCLUSIONS

Findings show that, from a psychometric standpoint, the youth version of the CASP is a promising new self-report measure of activity and participation. As youth perceive their activity and participation levels differently than their parents, it is important to collect data from both sources to obtain a more comprehensive understanding of this aspect of youths' lives.

Effects of phytic acid and exercise on some serum analytes in rats orally exposed to diets supplemented with cadmium

Cadmium is an environmental pollutant of increasing worldwide concern. It has been reported to be high in the soil where food crops are grown in some parishes of Jamaica. Surprisingly, no adverse effect of cadmium has been reported among the Jamaican population. However, phytic acid has also been shown to be high in some food crops grown in Jamaica. In this study, we evaluated the effects of phytic acid (1 %) and exercise on the metabolism of cadmium (5 mg cadmium/kg body weight) in rats. Five groups of rats were fed as follows: rats fed control diet, control diet supplemented with cadmium and subjected to exercise, control diet supplemented with phytic acid plus cadmium and subjected to exercise, control diet supplemented with cadmium plus phytic acid, and control diet supplemented with cadmium only. The animals were fed for 4 weeks and then sacrificed. Blood samples were collected for some biochemical assays. Percentage weight loss (28.42 %) was greatest in the group that had cadmium supplement only. The group fed control diet supplemented with cadmium only displayed increased liver enzymes and electrolytes except for the significant decrease in bicarbonate compared to other test groups. Similarly, blood urea nitrogen and uric acid were increased in the group fed cadmium supplement only compared to other test groups. Total cholesterol trended downwards in the test groups compared to control. These observations suggest that consumption of diet high in phytic acid with relatively high physical activity may be protective against the adverse effects of cadmium.

Effect of bauxite mineralized soil on residual metal levels in some post harvest food crops in Jamaica

The concentrations of nine residual metals in some Jamaican foods were determined using inductively coupled plasma mass spectrometry technique. Cadmium concentration was highest in yellow yam (0.21 mg/kg). Sweet potato had the highest concentrations of lead (0.31 mg/kg), arsenic (0.70 mg/kg) and mercury (0.35 mg/kg). Samples from Grove Place exceeded the regulatory limits of 0.1 mg/kg for cadmium, lead and arsenic and 0.05 mg/kg for mercury. Significant correlations were found between soil and agricultural produce concentrations for cadmium and lead (r(2) ≥ 0.5). These results suggest that the elements were available in soluble forms in the soil for absorption by food crops.

Children's and parents' beliefs regarding the value of walking: rehabilitation implications for children with cerebral palsy

BACKGROUND

Walking for children with cerebral palsy (CP) has physiological and functional benefits, but also holds symbolic significance that largely remains unexplored. The aims of this pilot study were to describe beliefs about the value of walking held by children with CP and their parents, and to examine how these beliefs inform rehabilitation choices and perceptions of 'success'.

METHODS

A critical qualitative design was employed. Six parents and six children with CP (Gross Motor Function Classification System III or IV, aged 9 to 18 years) each participated in a private interview. Analyses examined the relationship between dominant social beliefs regarding walking and participants' accounts.

RESULTS

Parents' accounts revealed that all adopted a stance of doing something/trying anything as part of being a 'good parent' and maintaining hope. Tapering of walking interventions contributed to feelings of guilt and doubt. Children primarily viewed walking as exercise rather than functional. Their accounts also demonstrated how they internalized negative attitudes towards disability and judged themselves accordingly.

CONCLUSIONS

The results of this pilot study provide provisional evidence regarding how dominant social values regarding walking and disability are taken up by parents and children. They suggest that rehabilitation programmes need to consider how they may unintentionally reinforce potentially harmful choices, and how best to engage families in discussions of their evolving values and treatment priorities. Further research is needed with a larger sample.

Multiple protein extract microarray for profiling human food-specific immunoglobulins A, M, G and E

Existing food immunoglobulin (Ig) tests require large volumes of serum, are limited to one immunoglobulin class, are not amenable to high throughput analysis and only give a limited picture of the immunological response to food antigens. Conversely a new generation of Component Resolved Diagnostic systems using pure proteins is highly specific and totally dependent on the availability of the protein in its recombinant or natural origin form. Here we demonstrate a proof-of-concept of a microarray test based on protein extracts of food components. Our approach relies on innovations on three different fronts: the novelty of using arrayed food samples sequentially extracted with detergent and chaotropic agents, the ability to measure four different Ig classes simultaneously and the ability to analyse the generated data via a suitable bioinformatics/statistical analysis interface. This approach combines high numerical power of microarrays with automation, high throughput analysis and enables detailed investigation of the Ig profiles to food antigens. The prototype shown contains extracts of approximately 350 food ingredients that cover most of the food products found in the UK. Here we showed that the use of a sequential extraction technique to solubilise and then denature food samples has its benefits in the assessment of variations in antigenicity when tested with human sera. A patient dependent degree of class specificity was observed with human sera (IgG specificity correlates well with IgA>IgM>>>>>IgE). Besides generating a simultaneous profile for IgA, IgM, IgG and IgE the array system has shown good discrimination between challenge responders in atopic and non-atopic individuals. Poly- and mono-specific IgE responders were easily identified. The mathematical modelling of specific IgE content showed good correlations when compared with established IgE antibody testing assay (UniCAP). Although in its proof-of-principle stages, the immune profiling technique described here has the potential to provide unique insights into exposure/sensitization and establish relationships between specific immunoglobulin classes and subclasses against food protein antigens. In further developments, the immune profiling technique could also be extended to other related areas such as parasite and bacterial gut infection. Full analyses of large longitudinal and retrospective clinical trials are on going to determine the positive and negative predictive values of the technique.

Pilot study of fitness training and exercise testing in polyarticular childhood arthritis

OBJECTIVE

To 1) assess the safety and feasibility of laboratory-based exercise testing in juvenile idiopathic arthritis (JIA), 2) test the safety and feasibility of a 3-month exercise program in JIA, 3) assess pain during exercise in JIA, 4) compare ratings of perceived effort (RPE) with heart rate (HR) achieved, and 5) estimate the training effect on metabolic efficiency of gait as measured by submaximal exercise testing.

METHODS

Nine children with JIA were enrolled in a 12-week circuit training program involving pool, stationary bicycle, treadmill, and Fitball. They underwent formal exercise testing before and after the program, underwent a full joint assessment, were administered the Childhood Health Assessment Questionnaire and Juvenile Arthritis Functional Status Index, and were assessed for overall quality of life and health-related quality of life. A visual analog scale was used to assess pain during testing and training, and the Borg scale was used to measure RPE.

RESULTS

Children with JIA were able to participate in exercise testing without any significant problems. Children with severe hip disease dropped out of the exercise program due to pain during the exercise sessions and worsened arthritis symptoms. Target HR was achieved and correlated with RPE in the bicycle and treadmill sessions. Submaximal exercise testing showed an improvement with a small to moderate effect size.

CONCLUSION

This study suggests that it is safe, feasible, and acceptable for children with arthritis, in the absence of severe hip involvement, to participate in formal exercise testing and structured fitness programs.

Circulating endothelial microparticles in acute ischemic stroke: a link to severity, lesion volume and outcome

BACKGROUND

Endothelial membrane microparticles (EMP) in plasma are elevated in several vascular diseases.

OBJECTIVES

To test the hypothesis that EMP would be increased in patients with acute ischemic stroke and would correlate with stroke severity, brain lesion volume and outcome.

PATIENTS AND METHODS

Forty-one patients were studied and divided into two groups based on the National Institutes of Health Stroke Scale (NIHSS) score: 20 patients with mild stroke (NIHSS score < 5) and 21 patients with moderate-severe stroke (NIHSS score > or = 5). Lesion volume was measured using diffusion-weighted magnetic resonance imaging and discharge outcome was based on the discharge Barthel and Rankin scores. Twenty-three age-matched control subjects were also studied. Using flow cytometry, endoglin-positive EMP: CD105+ CD41a-CD45- (E(+)EMP), specific endothelial EMP expressing VE-cadherin and endoglin: CD105+CD144+ (C(+)EMP), EMP expressing phosphatidylserine: CD105+PS+ CD41a- (PS(+)EMP) and EMP expressing ICAM-1: CD105+CD54+ CD45- (I(+)EMP) were analyzed.

RESULTS

Significantly higher PS(+)EMP counts were observed in the group of acute ischemic stroke patients [median 59 (25th-75th percentile: 28-86) MP microL(-1)] relative to the controls [28 (14-36) MP microL(-1)] (P = 0.002). All four EMP phenotypes studied were elevated in the subgroup of moderate-severe stroke patients relative to the controls (all P < 0.05). In the patients with acute ischemic stroke three EMP phenotypes (E(+)EMP, PS(+)EMP and I(+)EMP) correlated significantly with brain lesion volume, with I(+)EMP (P = 0.002) showing the strongest correlation. Admission counts of C(+)EMP (P = 0.0003) and E(+)EMP (P = 0.003) correlated significantly with discharge clinical outcome.

CONCLUSIONS

Certain circulating EMP phenotypes may be associated with severity, lesion volume and outcome of acute ischemic stroke. EMP analysis shows promising contribution to understanding stroke pathophysiology.

An evaluation of the responsiveness of a comprehensive set of outcome measures for children and adolescents with traumatic brain injuries

The relative responsiveness of nine outcome measure scales was evaluated with 33 children and adolescents (aged 4-18 years) who had sustained traumatic brain injuries. Scales were selected to evaluate outcomes from each of the World Health Organization (WHO) International Classification of Functioning, Disability and Health domains. The outcome measures were administered to all participants during their inpatient rehabilitation stay and again at a follow-up clinic visit. No single outcome measure captured the diversity of improvement in this sample. The measures agreed that improvement had occurred, but did not agree about which children were improving. This result suggests that the scales were measuring different skills and outcomes. Three of the measures used in combination, either the Child Health Questionnaire or the Functional Independence Measure for Children, the American Speech-Language-Hearing Association National Outcome Measures System (Birth to Kindergarten NOMS/School-aged Health Care) and the Gross Motor Function Measure, are sufficient to detect change in each of the children where change occurred. The Pediatric Evaluation of Disability Inventory and the MultiAttribute Health Status Classification were the least responsive of the nine measures used.

Paper 9: An Investigation of the Friction and Lubrication in Human Joints

The work carried out applies to lubricated sliding surfaces in living and artificial human joints, with particular application to the hip, one of the principal load-bearing synovial joints in the body.

Results are presented concerning the dimensions of the fluid-filled space between the articular surfaces of an unloaded human hip joint. The surface quality of articular surfaces has been assessed in a number of cases.

Friction and lubrication experiments have been carried out on a reciprocating type of test machine using samples of articular cartilage and various artificial materials.

It is hoped that the information gained from these experiments will lead to a clearer understanding of the load-carrying capacity of a human joint which is lubricated with synovial fluid.

Analysis of ‘Boosted Lubrication’ in Human Joints

The load-bearing human joint is a self-acting dynamically loaded bearing which employs a porous and elastic bearing material (articular cartilage) and a highly non-Newtonian lubricant (synovial fluid).

The authors' understanding is that the human joint experiences fluid-film (including elastohydrodynamic), mixed and boundary lubrication in its various operating conditions. It has been recognized that squeeze-film action is capable of providing considerable protection to the cartilage surface once a fluid film is generated (6) (8)§. Furthermore, the possibility of an increasing concentration of hyaluronic acid in synovial fluid during the squeeze-film action due to the porous nature of the cartilage and its surface topography and the known relationship between this concentration and the effective viscosity (7) has led to the concept of ‘boosted lubrication’ as an important feature of joint behaviour (10).

A mathematical analysis of the concept of boosted lubrication of human joints is presented in this paper. The predictions of the analysis are shown to be in good agreement with experimental findings (12).

Immune responses following experimental human hookworm infection

To characterize the immune response following primary human hookworm infection, an adult volunteer was infected with 50 L3 larvae of Necator americanus, reinfected 27 months later and followed for a further 6 months. Clinical signs, blood picture, ex-vivo peripheral blood cytokine production (IFN-gamma, IL-5, IL-13, IL-10 to mitogen and hookworm antigen), acute phase proteins (APP) (C-reactive protein, CRP and alpha1-antitrypsin, alpha1-AT) and antibody levels were determined. Dermatitis, oedema, mild nausea and abdominal discomfort followed the primary infection. Eosinophil counts peaked early during both infections but remained elevated ( approximately 18%) throughout. Transient production of IL-5, IL-13 and APP also followed infection but there were negligible levels of IFN-gamma or IL-10. The onset of nausea, oedema and the initial rise in CRP, alpha1-AT, eosinophilia and IL-5 coincided (days 13-27) with the late larval migration and early establishment of the preadult worms in the intestine. Apart from the eosinophilia these responses declined to baseline levels within 4 months and were less pronounced on re-infection.

Elevated pro-inflammatory CD4+CD28- lymphocytes and stroke recurrence and death

OBJECTIVE

To determine if the CD4+CD28- T-cell subset is expanded in patients with recurrent stroke or death after acute ischemic stroke. This subset of the peripheral blood T-cell lymphocyte population has a strong pro-inflammatory and tissue-damaging potential.

METHODS

Consecutive patients within the first 48 hours of ischemic stroke were prospectively studied. Peripheral blood CD4+CD28- cells were quantified by flow cytometry. The study endpoint was recurrent stroke or death from any cause during 1 year of follow-up.

RESULTS

One hundred six patients (mean age 75.0 +/- 13.5 years; 50 women) were studied. The median CD4+CD28- cell count was 4.5% (range 0.2 to 72.2%). Twenty-seven endpoints (10 recurrent strokes and 17 deaths) occurred during follow-up. Stroke recurrence/death rates were significantly associated with increasing CD4+CD28- counts, rising from 14.2% in patients with CD4+CD28- levels of <1.0 to 48.1% for those with CD4+CD28- counts of >8.0% (p = 0.003, Cochran linear test of trend). Higher CD4+CD28- counts were also present in patients with a history of prior stroke (p = 0.03). After adjustment for age, admission NIH Stroke Scale score, prior stroke, and atrial fibrillation, CD4+CD28- counts of >8.0% were associated with a cumulative hazard ratio of 5.81 (95% CI: 1.58 to 21.32) for stroke recurrence or death.

CONCLUSIONS

Rising counts of circulating CD4+CD28- cells are associated with an increasing risk of stroke recurrence and death, in addition to an observed association with prior stroke. Expansion of this T-cell subset presumably represents a biomarker and possibly a contributory pathogenic mechanism of recurrent stroke and death after ischemic stroke.

Emphysematous cystitis: rapid resolution of symptoms with hyperbaric treatment: a case report

INTRODUCTION

Emphysematous cystitis is a rare disease that occurs most often in elderly diabetic patients characterized by gas formation in the bladder wall due to infection. The infecting organism is usually an aerobic bacterium, most commonly E. coli although anaerobic species have also been reported. We report the use of hyperbaric oxygen in a patient with emphysematous cystitis and air in the femoral vein in which the treatment rapidly resolved the symptoms and radiological abnormalities.

METHODS

A 65-year-old female presented to the Emergency Department with altered mental status, weakness, dark urine, dysuria and fever. She was febrile and lethargic. Abdominal exam showed suprapubic tenderness. Urinalysis was positive for white blood cells and bacteria. A CT scan of the abdomen demonstrated extensive air in the bladder wall with an air bubble in the femoral vein. Presumptive diagnosis was urinary tract infection, emphysematous cystitis, and sepsis. A question of air embolism was raised due to the intravascular gas. The patient was treated with hyperbaric oxygen (2.85 atm abs, 90 minutes) on two separate occasions in the first 12 hours. Within 24 hours, the patient's condition rapidly improved. Repeat CT scan 48 hours after admission showed near complete resolution of the emphysematous cystitis. The patient grew Klebsiella pneumonia from her urine.

CONCLUSIONS

Emphysematous cystitis is a rare condition caused by either aerobic or anaerobic bacteria and may be associated with both bladder wall and intravascular gas formation. Hyperbaric oxygen therapy has not been previously reported as a treatment modality. The rapid improvement in our patient may indicate a role for hyperbaric oxygen in addition to IV hydration and antibiotics in this disease.