Biomedical subjects
Publications and source records attributed to Richard Hughes.
Osteoblastoma is a rare primary bone tumour which is well-described in the spine and sacrum. We report a case of histologically confirmed osteoblastoma in a 20-year-old male which crossed the sacroiliac joint. This has not previously been described to our knowledge. The imaging features of osteoblastoma and sacroiliac joint involvement by bone tumours are reviewed.
OBJECTIVE: Somatosensory function declines with diabetic neuropathy and often with stroke, resulting in diminished motor performance. Recently, it has been shown that input noise can enhance human sensorimotor function. The goal of this study was to investigate whether subsensory mechanical noise applied to the soles of the feet via vibrating insoles can be used to improve quiet-standing balance control in 15 patients with diabetic neuropathy and 15 patients with stroke. Sway data of 12 healthy elderly subjects from a previous study on vibrating insoles were added for comparison. METHODS: Five traditional sway parameters and three sway parameters from random-walk analysis were computed for each trial (no noise or noise). RESULTS: Application of noise resulted in a statistically significant reduction in each of the eight sway parameters in the subjects with diabetic neuropathy, the subjects with stroke, and the elderly subjects. We also found that higher levels of baseline postural sway in sensory-impaired individuals was correlated with greater improvements in balance control with input noise. INTERPRETATION: This work indicates that noise-based devices could ameliorate diabetic and stroke impairments in balance control.
Oxylipin metabolism represents one of many defence mechanisms employed by plants. It begins with the oxygenation of polyunsaturated fatty acids by lipoxygenases to form fatty acid hydroperoxides that are substrates for several enzymes, including specialized cytochrome P450s known as CYP74s. The targeting of a new CYP74, a 9-hydroperoxide lyase (HPL) from almonds, to the endomembrane system and lipid bodies, both as enzyme activity in almond seeds and as GFP fusions transiently expressed in tobacco protoplasts, is described. Such association of a CYP74 with lipid bodies has not been reported previously. Also described are the properties of a 9-HPL gene, the developmental regulation of its expression, the production and characterization of recombinant 9-HPL in Escherichia coli, and the developmental correlation between gene expression, enzyme activity, and the appearance of volatile C9 aldehydes from HPL action.
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The xylanase inhibitor protein I (XIP-I), recently identified in wheat, inhibits xylanases belonging to glycoside hydrolase families 10 (GH10) and 11 (GH11). Sequence and structural similarities indicate that XIP-I is related to chitinases of family GH18, despite its lack of enzymatic activity. Here we report the identification and biochemical characterization of a XIP-type inhibitor from rice. Despite its initial classification as a chitinase, the rice inhibitor does not exhibit chitinolytic activity but shows specificities towards fungal GH11 xylanases similar to that of its wheat counterpart. This, together, with an analysis of approximately 150 plant members of glycosidase family GH18 provides compelling evidence that xylanase inhibitors are largely represented in this family, and that this novel function has recently emerged based on a common scaffold. The plurifunctionality of GH18 members has major implications for genomic annotations and predicted gene function. This study provides new information which will lead to a better understanding of the biological significance of a number of GH18 'inactivated' chitinases.
OBJECTIVES: To study the effects of robotic rehabilitation in persons with chronic motor impairments after stroke and to examine whether improvements in motor abilities were sustained 4 months after the end of therapy. DESIGN: Pretest-posttest design. SETTING: Rehabilitation hospital, outpatient care. PARTICIPANTS: Volunteer sample of 42 persons with persistent hemiparesis from a single, unilateral stroke within the past 1 to 5 years. INTERVENTION: Robotic therapy for the paretic upper limb consisted of either sensorimotor active-assistive exercise, or progressive-resistive training during repetitive, planar reaching tasks, 3 times a week for 6 weeks. MAIN OUTCOME MEASURES: Modified Ashworth Scale, Fugl-Meyer Assessment (FMA), Motor Status Scale (MSS) score, and Medical Research Council motor power score. RESULTS: No significant differences were found among pretreatment clinical evaluations. Statistically significant gains from admission to discharge and from admission to follow-up (P<.05) were found on the FMA, MSS score for shoulder and elbow, and motor power score. CONCLUSIONS: Short-term, goal-directed robotic therapy can significantly improve motor abilities of the exercised limb segments in persons with chronic stroke that are sustained 4 months after discharge. This suggests that motor recovery can be enhanced by repetitive exercise training more than 1 year after stroke.
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OBJECTIVE: This study examined whether incorporating progressive resistive training into robot-aided exercise training provides incremental benefits over active-assisted robot-aided exercise for the upper limb after stroke. DESIGN: A total of 47 individuals at least 1 yr poststroke were enrolled in this 6-wk training protocol. Paretic upper limb motor abilities were evaluated using clinical measures and a robot-based assessment to determine eligibility for robot-aided progressive resistive training at study entry. Subjects capable of participating in resistance training were randomized to receive either active-assisted robot-aided exercises or robot-aided progressive resistance training. Subjects who were incapable of participating in resistance training underwent active-assisted robotic therapy and were again screened for eligibility after 3 wks of robotic therapy. Those subjects capable of participating in resistance training at 3 wks were then randomized to receive either robot-aided resistance training or to continue with robot-aided active-assisted training. RESULTS: One subject withdrew due to unrelated medical issues, and data for the remaining 46 subjects were analyzed. Subjects in all groups showed improvement in measures of motor control (mean increase in Fugl-Meyer of 3.3; 95% confidence interval, 2.2-4.4) and maximal force (mean increase in maximal force of 3.5 N, P = 0.027) over the course of robot-aided exercise training. No differences in outcome measures were observed between the resistance training groups and the matched active-assisted training groups. Subjects' ability to perform the robotic task at the time of group assignment predicted the magnitude of the gain in motor control. CONCLUSION: The incorporation of robot-aided progressive resistance exercises into a program of robot-aided exercise did not favorably or negatively affect the gains in motor control or strength associated with this training, though interpretation of these results is limited by sample size. Individuals with better motor control at baseline experienced greater increases in motor control with robotic training.
Electromagnetic tracking devices are used in many biomechanics applications. Previous studies have shown that metal located within the working field of direct current electromagnetic tracking devices produces significant errors. However, the effect of sampling rate on the errors produced in a metallic environment has never been studied. In this study, the accuracy of Ascension Technologies' Flock of Birds was evaluated at sampling rates of 20, 60, 100, and 140 Hz, in the presence of both aluminum and steel. Aluminum interference caused an increase in measurement error as the sampling rate increased. Conversely, steel interference caused a decrease in measurement error as the sampling rate increased. We concluded that the accuracy of the Flock of Birds tracking system can be optimized in the presence of metal by careful choice in sampling rate.
The aim of this study was to provide an incremental cost-effectiveness analysis comparing intravenous immunoglobulin (IVIg) and prednisolone treatment for chronic inflammatory demyelinating polyradiculoneuropathy. Patients were recruited to a double-blind randomized crossover trial from nine European centres and received either prednisolone or IVIg during the first 6-week treatment period on which the economic evaluation was based. A societal perspective was adopted in measuring service use and costs, although the costs of lost employment were not included. The main outcome measure in the economic evaluation was the number of quality adjusted life years (QALYs) gained, with change in a 11-point disability scale used to measure clinical outcomes. Service use and quality of life data were available for 25 patients. Baseline costs were controlled for using a bootstrapped multiple regression model. The cost difference between the two treatments was estimated to be euro 3754 over the 6-week period. Health-related quality of life, as measured by the EuroQol EQ-5D instrument, increased more in the IVIg group but the difference was not statistically significant. Using a net-benefit approach it was shown that the probability of IVIg being cost-effective in comparison with prednisolone was 0.5 or above (i.e. was more likely to be cost-effective than cost-ineffective) only if one QALY was valued at over euro 250 000. The cost-effectiveness of IVIg is greatly affected by the price of IVIg and the amount administered. The impact of later side-effects of prednisolone on long-term costs and quality of life are likely to reduce the cost per QALY of IVIg treatment.
OBJECTIVES: To ascertain the natural history and to stratify risks for the development of late posttraumatic seizures in individuals with moderate to severe traumatic brain injury (TBI). DESIGN: Prospective, observational study of individuals with TBI admitted to 4 trauma centers within 24 hours of injury. SETTING: Four tertiary care trauma centers in urban areas. PARTICIPANTS: A total of 647 individuals (>/=16 y) with any of the following abnormal computed tomography (CT) scan findings: extent of midline shift and/or cisternal compression or presence of any focal pathology (eg, punctate, subarachnoid, or intraventricular hemorrhage; cortical or subcortical contusion; extra-axial lesions) during the first 7 days postinjury or best Glasgow Coma Scale (GCS) score of </=10 during the first 24 hours post-TBI. Subjects were enrolled from August 1993 through September 1997 and followed for up to 24 months, until death or their first late posttraumatic seizures. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Cumulative probability, relative risk, and survival analyses were used to stratify risks for development of late postttraumatic seizures on the basis of demographic factors, etiology of injury, initial GCS, early posttraumatic seizures, time post-TBI, types of intracerebral lesion by CT scan, and number and types of intracranial procedures. RESULTS: Sixty-six individuals had a late posttraumatic seizures; 337 had no late posttraumatic seizures during full 24-month follow-up; 167 had no late posttraumatic seizures during time followed (<24 mo); and 54 were placed on anticonvulsants without a late posttraumatic seizures, whereas 23 died before their first late posttraumatic seizures. The highest cumulative probability for late posttraumatic seizures included biparietal contusions (66%), dural penetration with bone and metal fragments (62.5%), multiple intracranial operations (36.5%), multiple subcortical contusions (33.4%), subdural hematoma with evacuation (27.8%), midline shift greater than 5mm (25.8%), or multiple or bilateral cortical contusions (25%). Initial GCS score was associated with the following cumulative probabilities for development of late posttraumatic seizures at 24 months: GCS score of 3 to 8, 16.8%; GCS score of 9 to 12, 24.3%; and GCS score of 13 to 15, 8.0%. CONCLUSIONS: Stratification by CT scan findings and neurosurgical procedures performed were the most useful findings in defining individuals at highest risk for late posttraumatic seizures.
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Smoothness is characteristic of coordinated human movements, and stroke patients' movements seem to grow more smooth with recovery. We used a robotic therapy device to analyze five different measures of movement smoothness in the hemiparetic arm of 31 patients recovering from stroke. Four of the five metrics showed general increases in smoothness for the entire patient population. However, according to the fifth metric, the movements of patients with recent stroke grew less smooth over the course of therapy. This pattern was reproduced in a computer simulation of recovery based on submovement blending, suggesting that progressive blending of submovements underlies stroke recovery.
This multicentre randomised double blind crossover trial tested the short term efficacy of intravenous immunoglobulin (IVIg) 2.0 g/kg given over 24 or 48 hours in patients with paraproteinaemic demyelinating neuropathy (PDN). Twenty-two patients were randomised and completed the trial. After 2 weeks, the overall disability grade decreased during both IVIg treatment and placebo but neither change was significant nor was the mean difference between the treatment effects. After 4 weeks the overall disability decreased by a mean of 0.55 [0.67] grades during the IVIg period (p = 0.001) while it was substantially unmodified during the placebo period. The mean difference between the treatment effects was significant (p = 0.05). Overall during the IVIg period 10 patients improved and 11 were stable and one got worse. During the placebo period 4 patients improved, 4 deteriorated and 14 were stable. Many secondary outcome measures, including Rankin scale, time to walk 10 metres, grip strength, sensory symptoms score were significantly better during IVIg treatment. Two serious adverse events occurred during the trial, both during placebo treatment. In conclusion the trial showed some short-term benefit of IVIg in about half of the patients confirming previous observation.
BACKGROUND AND PURPOSE: The American Stroke Association (ASA) assembled a multidisciplinary group of experts to develop recommendations regarding the potential effectiveness of establishing an identification program for stroke centers and systems. "Identification" refers to the full spectrum of models for assessing and recognizing standards of quality care (self-assessment, verification, certification, and accreditation). A primary consideration is whether stroke center identification might improve patient outcomes. METHODS: In February 2001, ASA, with the support of the Stroke Council's Executive Committee, decided to embark on an evaluation of the potential impact of stroke center identification. HealthPolicy R&D was selected to prepare a comprehensive report. The investigators reported on models outside the area of stroke, ongoing initiatives within the stroke community (such as Operation Stroke), and state and federal activities designed to improve care for stroke patients. The investigators also conducted interviews with thought leaders in the stroke community, representing a diverse sampling of specialties and affiliations. In October 2001, the Advisory Working Group on Stroke Center Identification developed its consensus recommendations. This group included recognized experts in neurology, emergency medicine, emergency medical services, neurological surgery, neurointensive care, vascular disease, and stroke program planning. RESULTS: There are a variety of existing identification programs, generally falling within 1 of 4 categories (self-assessment, verification, certification, and accreditation) along a continuum with respect to intensity and scope of review and consumption of resources. Ten programs were evaluated, including Peer Review Organizations, trauma centers, and new efforts by the National Committee on Quality Assurance and the Joint Commission on the Accreditation of Healthcare Organizations to identify providers and disease management programs. The largest body of literature on clinical outcomes associated with identification programs involves trauma centers. Most studies support that trauma centers and systems lead to improved mortality rates and patient outcomes. The Advisory Working Group felt that comparison to the trauma model was most relevant given the need for urgent evaluation and treatment of stroke. The literature in other areas generally supports the positive impact of identification programs, although patient outcomes data have less often been published. In the leadership interviews, participants generally expressed strong support for pursuing some form of voluntary identification program, although concerns were raised that this effort could meet with some resistance. CONCLUSIONS: Identification of stroke centers and stroke systems competencies is in the best interest of stroke patients in the United States, and ASA should support the development and implementation of such processes. The purpose of a stroke center/systems identification program is to increase the capacity for all hospitals to treat stroke patients according to standards of care, recognizing that levels of involvement will vary according to the resources of hospitals and systems.
Nurses caring for patients with brain injuries need to be aware of the effect of such injuries on brain anatomy and the problems associated with a rise in intracranial pressure. This paper examines the main aspects of nursing care for brain-injured patients. Further research is required in many areas of management in this patient group to provide up-to-date, evidence-based care.
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