Biomedical subjects

Tariq Rahman

Publications and source records attributed to Tariq Rahman.

6 recordsLinked to original sources

PubMed2006

Risperidone irreversibly binds to and inactivates the h5-HT7 serotonin receptor.

Risperidone displays a novel mechanism of antagonism of the h5-HT7 receptor. Pretreatment of the cells with 5 or 20 nM risperidone, followed by removal of the drug from the media, renders the 5-HT7 receptors unresponsive to 10 microM 5-HT for at least 24 h. Thus, risperidone seems to be producing a rapid, long-lasting inactivation of the h5-HT7 receptor. Whole-cell radioligand binding studies indicate that risperidone interacts in an irreversible or pseudo-irreversible manner with the h5-HT7 receptor, thus producing the inactivation. Internalization of the h5-HT7 receptor was not detected by monitoring green fluorescent protein-labeled fluorescent forms of the h5-HT7 receptor exposed to 20 nM risperidone. Ten other antagonists were tested for h5-HT7-inactivating properties, and only 9-OH-risperidone and methiothepin were found to demonstrate the same anomalous properties as risperidone. These results indicate that the h5-HT7 receptor may possess unique structural features that allow certain drugs to induce a conformation resulting in an irreversible interaction in the intact membrane environment. This may indicate that the h5-HT7 receptor is part of a subfamily of G-protein-coupled receptors (GPCRs) possessing this property or that many GPCRs have the potential to be irreversibly blocked, but only select drugs can induce this effect. At the very least, the possibility that highly prescribed drugs, such as risperidone, are irreversibly antagonizing GPCR function in vivo is noteworthy.

Binding, Competitive↗

PubMed2006

Automating arm movement training following severe stroke: functional exercises with quantitative feedback in a gravity-reduced environment.

An important goal in rehabilitation engineering is to develop technology that allows individuals with severe motor impairment to practice arm movement without continuous supervision from a rehabilitation therapist. This paper describes the development of such a system, called Therapy WREX or ("T-WREX"). The system consists of an orthosis that assists in arm movement across a large workspace, a grip sensor that detects hand grip pressure, and software that simulates functional activities. The arm orthosis is an instrumented, adult-sized version of the Wilmington Robotic Exoskeleton (WREX), which is a five degrees-of-freedom mechanism that passively counterbalances the weight of the arm using elastic bands. After providing a detailed design description of T-WREX, this paper describes two pilot studies of the system's capabilities. The first study demonstrated that individuals with chronic stroke whose arm function is compromised in a normal gravity environment can perform reaching and drawing movements while using T-WREX. The second study demonstrated that exercising the affected arm of five people with chronic stroke with T-WREX over an eight week period improved unassisted movement ability (mean change in Fugl-Meyer score was 5 points +/- 2 SD; mean change in range of motion of reaching was 10%, p < 0.001). These results demonstrate the feasibility of automating upper-extremity rehabilitation therapy for people with severe stroke using passive gravity assistance, a grip sensor, and simple virtual reality software.

Adult↗

PubMed2004

Compliance monitoring of brace treatment for patients with idiopathic scoliosis.

STUDY DESIGN: Prospective, blinded study to evaluate compliance with treatment. OBJECTIVE: To evaluate objectively idiopathic scoliosis patients' compliance with Wilmington brace treatment. SUMMARY OF BACKGROUND DATA: Patients' compliance with brace treatment for idiopathic scoliosis traditionally has been determined from patient or parent interviews or both; however, the hours reported by patients are subjective and consequently are not accurate. METHODS: Study participants were 61 consecutive patients with idiopathic scoliosis: 54 girls and 7 boys. Inclusion criteria were curvature of more than 20 degrees and less than 45 degrees of Cobb angle before brace treatment. Actual hours worn per day were measured using a compliance monitor, and compliance was determined by the percentage of actual hours worn in accordance with the prescribed regimen. Accuracy of compliance from hours reported by patients was compared with actual hours measured by the monitor. Correlations between compliance and prescribed regimen and age were analyzed. RESULTS: The overall compliance measured by the monitor was 75 +/- 27% (mean +/- S.D.), and the frequency distribution was similar to a Gaussian distribution. The compliance determined from hours reported by patients was 85 +/- 24%, which was higher than that from actual hours measured by the monitor (P = 0.01). There was a negative correlation between age and compliance (rho = -0.30, P = 0.025); 10-, 12-, and 14-year-old patients had 84, 77, and 60% average compliance, respectively. Compliance among patients with different prescribed regimens (8, 12, 16, or 23 hours of wear) showed no statistical difference (P = 0.361). CONCLUSIONS: Patients with idiopathic scoliosis complied with 75% of prescribed regimen on average and overreported their hours of brace wear to their physician. Age affected compliance. There was no statistical difference in compliance among patients with different prescribed regimens. The present study confirms the need for a compliance monitor to accurately evaluate use and outcome of brace treatment.

Adolescent↗

PubMed2003

The association of backpack use and back pain in adolescents.

STUDY DESIGN: A cross-sectional study comprising the first phase of an ongoing, longitudinal prospective study was conducted. OBJECTIVE: To investigate the relation between backpack use and back pain in adolescents. SUMMARY OF BACKGROUND DATA: The prevalence of nonspecific back pain increases dramatically during adolescence from less than 10% in the pre-teen-age years up to 50% in 15- to 16-year-olds. There is widespread concern that heavy backpacks carried by adolescents contribute to the development of back pain. METHODS: A total of 1126 children, ages 12 to 18 years, participated by completing a questionnaire about their health, activities, and backpack use. Each child's body weight, height, and backpack weight were measured. A child was classified as having back pain if one or more of the following were reported during the preceding month: neck or back pain that had interfered with school or leisure, neck or back pain with a severity rating of 2 or more on a scale 0 to 10, a visit to a physician or therapist for neck or back pain, or exemption from physical education or sports because of neck or back pain. RESULTS: Of 1122 backpack users, 74.4% were classified as having back pain, validated by significantly poorer general health, more limited physical functioning, and more bodily pain. As compared with no or low use of backpacks at school, heavy use (odds ratio, 1.98; P < 0.0001) was independently associated with back pain. Female gender and larger body mass index also were significantly associated with back pain. As compared with adolescents who had no back pain, adolescents with back pain carried significantly heavier backpacks that represented a significantly greater percentage of their body weights. CONCLUSION: The use of backpacks during the school day and backpack weights are independently associated with back pain.

Adolescent↗

PubMedDate not supplied

The association between brace compliance and outcome for patients with idiopathic scoliosis.

This was a prospective study on the association of brace compliance and curve progression in idiopathic scoliosis. Compliance was measured electronically by embedding a temperature sensor and logger in the Wilmington scoliosis brace. To date there have been no studies that relate objective measures of compliance in a scoliosis brace to treatment outcomes. Thirty-four subjects with idiopathic scoliosis were monitored over the duration of their brace wear. Compliance data were downloaded and analyzed. The compliance rate for the patients whose curve progressed (>5 degrees) was 62%; the compliance rate for the patients who did not progress was 85% (P = 0.004). In the group that had high compliance (>90%), one of the nine subjects' curves progressed (11%). In the group with low compliance (<90%), 14 of the 25 subjects' curves progressed (56%, P = 0.0075). Results indicate that the more patients comply with brace treatment, the better their chances of a favorable outcome.

Adolescent↗

PubMedDate not supplied

Passive exoskeletons for assisting limb movement.

This article presents the state of the art in passive devices for enhancing limb movement in people with neuromuscular disabilities. Both upper- and lower-limb projects and devices are described. Special emphasis is placed on a passive functional upper-limb orthosis called the Wilmington Robotic Exoskeleton (WREX). The development and testing of the WREX with children with limited arm strength are described. The exoskeleton has two links and 4 degrees of freedom. It uses linear elastic elements that balance the effects of gravity in three dimensions. The experiences of five children with arthrogryposis who used the WREX are described.

Adolescent↗