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Biomedical subjects

E R Ross

Publications and source records attributed to E R Ross.

At least 19 recordsLinked to original sources
PubMed1999

The clinical significance of the high-intensity zone on lumbar spine magnetic resonance imaging.

STUDY DESIGN: Prospective observational study of anular tears, diagnosed by a high-intensity zone within the anulus on lumbar spine magnetic resonance imaging, and correlation with the clinical features. OBJECTIVES: To assess the prevalence of high-intensity zones in patients who are investigated for back and leg pain and to determine whether there are clinical features that can be used for diagnosis of the presence of a high-intensity zone. SUMMARY OF BACKGROUND DATA: Results in previous studies have shown that the presence of a high-intensity zone is associated with reproduction of a patient's pain on stress discography. Neural compression on magnetic resonance imaging has been shown to be associated with back pain, but to date, no study has correlated the presence of a high-intensity zone with the clinical features. METHODS: The lumbar spine magnetic resonance images in 156 patients in whom back and leg pain were investigated were analyzed for the presence and appearances of high-intensity zones. The clinical features of those patients with a high-intensity zone but with no evidence of neural compression on magnetic resonance imaging were analyzed by t test and X2 test. RESULTS: A high-intensity zone occurred in patients at a prevalence of 45.5% and usually occurred posteriorly (77%) and posterolaterally (22%) within the anulus. There were no features within the history, functional disability questionnaire, or physical examination that aided in a clinical diagnosis of those patients with a high-intensity zone. CONCLUSIONS: A high-intensity zone is a common finding in patients in whom low back and leg pain are investigated, but the presence of a high-intensity zone does not define a group of patients with particular clinical features.

Adolescent↗
PubMed1999

Posterior lumbar interbody fusion. Association between disability and psychological disturbance in noncompensation patients.

STUDY DESIGN: An observational study of the relation between disability and psychological distress in patients with no on-going compensation claim who underwent posterior lumbar interbody fusion for chronic low back pain. OBJECTIVES: To study the change in the relation between disability and psychological distress after surgical management for low back pain. SUMMARY OF BACKGROUND DATA: Patient-related factors such as an on-going compensation claim and patient psychology are thought to influence the outcome of low back pain management. METHODS: Of the 58 patients who underwent posterior lumbar interbody fusion for low back pain between 1990 and 1995, 53 were observed for a mean duration of 2.7 years after surgery. Oswestry Disability scores and Distress and Risk Assessment Method scores were collected before surgery and at the follow-up examination. RESULTS: Improvement of 10 points on the Oswestry Disability Score was observed in 52.8% of the patients. However, the results in patients who were distressed before surgery were similar to the results observed in healthy patients. The difference in the Oswestry Disability Scores was 3.1 (95% confidence intervals [-9.9, 16.2], P = 0.297). The change in Distress and Risk Assessment Method scores showed a significant relation to change in the Oswestry Disability Scores (P = 0.033). CONCLUSIONS: Postoperative improvement in disability was not found to be related to preoperative psychology as measured by the Distress and Risk Assessment Method score. Change in disability is significantly related to change in distress.

Adult↗
PubMed1998

The therapeutic impact of lumbar spine MRI on patients with low back and leg pain.

UNLABELLED: The influence of lumbar spine magnetic resonance imaging (MRI) on the management of patients with low back and leg pain, with a clinical diagnosis of neural compression, has been investigated by a controlled prospective observational study. The clinical features of the patients at the time of request for MRI have been compared with the subsequent management in order to define the clinical indications for lumbar spine MRI. METHODS: Clinical history, physical examination findings and tests of functional and psychological disability were all recorded at the time of request for MRI. Following MRI, patients were assessed without knowledge of the MRI findings and a diagnosis and management plan recorded. Immediate access to the MRI report and hard copy films was then provided and a revised diagnosis and management plan made. The clinical features and MRI findings were compared with the subsequent management. RESULTS: Seventy-two patients were examined, 65 (90.3%) had leg pain as a predominant feature and abnormalities in neurological examination were found in 31 (43%). Twenty-three of 48 (47.9%) of patients with a pre MRI management plan of surgery were changed to conservative management following the MRI. The diagnosis altered in 50 % of cases with the largest change in diagnosis occurring in 13 patients where MRI did not confirm the clinical impression of nerve root compression. Seventeen patients with no abnormality of neurological testing were subsequently treated by surgery which included all 12 patients treated by spinal fusion. CONCLUSIONS: The major impact of MRI was to move patients towards conservative treatment. A variety of features in the history and physical examination as well as MRI findings are predictors for surgical treatment. The variety of diagnoses and surgical options available make it difficult to define clear clinical guidelines for the use of MRI.

Adult↗
PubMed1996

Energy expenditure of walking for adult patients with spinal cord lesions using the reciprocating gait orthosis and functional electrical stimulation.

A major factor influencing compliance with walking orthoses following spinal cord damage, is the energy requirement associated with them. We compared ambulatory energy expenditure in subjects using the reciprocating gait orthosis (RGO) with and without functional electrical stimulation (FES) of the thigh muscles at self selected walking speeds. Five adult subjects (median age 34 years, range 24-37) with spinal cord lesions ranging from C2 (incomplete) to T6 volunteered to participate in this study. All subjects were successful RGO users (median use 5.7 years, range 4.1-7.3). Walking speed (m/s), ambulatory energy consumption (J/kg/s) and energy cost (J/kg/m) were derived from oxygen uptake determined using the Douglas bag technique. We anticipated that subjects walking with FES would either: (a) walk at the same speed but reduce their energy cost or (b) increase their walking speed for the same (or less) energy cost. Walking speed and energy cost remained unchanged in one subject. One subject increased his walking speed by 14.0% and increased his energy consumption by 8.4%. His energy cost remained unchanged. Three subjects increased their walking speeds (by 12.4, 12.7 and 6.8%), energy consumption (by 25.9, 20.4 and 18.4% respectively) and energy cost (by 11.6, 6.8 and 10.5% respectively). We did not find a substantial benefit, in terms of energy expenditure, from the hybrid system when walking continuously for 5 min. We suggest that the hybrid system may be of greater benefit during prolonged walking, although other limitations, inherent in the RGO itself, may prevent an increase in compliance. Repetition of walking speed tests supported the reliability of our results. Tests on comparably aged, able-bodied subjects showed that an increase in energy cost of up to 5.8% was within the biological variability of the subject and the error of the methodology.

Adult↗
PubMed1996

Objective measurement of use of the reciprocating gait orthosis (RGO) and the electrically augmented RGO in adult patients with spinal cord lesions.

The purpose of the study was to measure objectively the home use of the reciprocating gait orthosis (RGO) and the electrically augmented (hybrid) RGO. It was hypothesised that RGO use would increase following provision of functional electrical stimulation (FES). Five adult subjects participated in the study with spinal cord lesions ranging from C2 (incomplete) to T6. Selection criteria included active RGO use and suitability for electrical stimulation. Home RGO use was measured for up to 18 months by determining the mean number of steps taken per week. During this time patients were supplied with the hybrid system. Three alternatives for the measurement of steps taken were investigated: a commercial digital pedometer, a magnetically actuated counter and a heel contact switch linked to an electronic counter. The latter was found to be the most reliable system and was used for all measurements. Additional information on RGO use was acquired using three patient diaries administered throughout the study and before and after the provision of the hybrid system. Testing of the original hypothesis was complicated by problems in finding a reliable measurement tool and difficulties with data collection. However, the results showed that overall use of the RGO, whether with or without stimulation, is low. Statistical analysis of the step counter results was not realistic. No statistically significant change in RGO use was found between the patient diaries. The study suggests that the addition of electrical stimulation does not increase RGO use. The study highlights the problem of objectively measuring orthotic use in the home.

Adult↗
PubMed1995

The reciprocating gait orthosis: long-term usage patterns.

OBJECTIVE: To investigate the frequency of nonusage of the reciprocating gait orthosis (RGO) in 85 patients supplied between 1986 and 1993. Reasons for nonusage and usage patterns were examined. DESIGN: Nonusage was determined from patient records and clinical knowledge. Patients were surveyed using a detailed questionnaire to produce information on usage patterns. SETTING: All patients had been treated as hospital outpatients. PATIENTS: Most patients had congenital or acquired spinal cord lesions. Postal questionnaires were sent to 81 patients 5 to 55 years of age (mean 20.4 years). Thirty-five patients replied. RESULTS: At a mean follow-up of 5.4 years, 71% of patients were classified as nonusers. Of the 35 respondents to the questionnaire (mean follow-up 5.5 years, range 4 to 7 years), 20 patients were nonusers. Median usage was 27 months in patients under age 18 and 24 months in adult patients. Significant differences were observed between nonusers and users in the areas of perception of the RGO as a functional tool, independence, and reliability and between the adult and the under 18 groups in the areas of weekly usage, function, independence, and reliability. CONCLUSION: The high level of nonusage of the RGO has implications for prescription practice. Identifying reasons for nonusage and acknowledging differences in use between age groups will help in patient assessment.

Activities of Daily Living↗
PubMed1994

Spatial learning deficits in the aged rat: neuroanatomical and neurochemical correlates.

To assess neurochemical and neuroanatomical correlates of age and spatial learning, aged Sprague-Dawley male rats (20-22 mo) were divided into two groups based on their ability to locate a hidden platform in a Morris water maze. An "old good" group of rats acquired the task as rapidly as young (3-6 mo) animals, whereas an "old poor" group of rats failed to show improvement on subsequent testing days. Age-related changes included (a) a significant decrease in the number of choline acetyltransferase (CHAT) immunoreactive cells in the ventral cell group of the septal complex (28%); (b) a decrease in caudate dopamine levels (-11%); and (c) an increase in 5-HIAA levels in the n. accumbens (+25%) and hippocampus (+18%). Spatial learning related changes in aged rats included: (a) an increase in medial frontal cortex 5-HIAA levels (52%) in the old good learners but not old poor learners with (b) a decrease in medial frontal cortex dopamine levels (-24%) only in the old poor learners group and (c) a decrease in n. accumbens DOPAC (-22%) and HVA (-23%) in the old good learners group only. The present study demonstrates age-related but not spatial learning related decrease in CHAT immunoreactive cells in the ventral cell group of the septal complex. Therefore, either the cholinergic cell loss in the septum is unrelated to the acquisition of spatial learning measured by the Morris water maze, or it is a permissive effect along with specific alterations in forebrain dopaminergic and serotonergic systems, particularly in the medial frontal cortex and n. accumbens. The above findings are consistent with findings seen in Alzheimer's disease where both basal forebrain cholinergic nuclei and cortical projecting brainstem monoamine systems are affected.

Aging↗
PubMed1992

Comparison of the abilities of Mycobacterium avium and Mycobacterium intracellulare to infect and multiply in cultured human macrophages from normal and human immunodeficiency virus-infected subjects.

Patients with AIDS commonly develop disseminated infections with Mycobacterium avium (MA) but not its close relative, M. intracellulare (MI). In non-AIDS patients who have these infections, the two species are about equally distributed. The higher incidence of infection with MA than with MI in AIDS patients might be due to the selective susceptibility of these patients to MA. This possibility was tested by comparing the abilities of MA and MI to infect and replicate in cultured macrophages from normal subjects and from patients with AIDS-related complex or AIDS. The macrophages were cultured in medium supplemented with 1 or 5% normal or patient sera or with 1% defined serum substitute. Replication of MA (serovar 4) or MI (serovars 16 and 17) in the macrophages was measured by CFU counts made from lysed samples of the macrophages taken at 0,4, and 7 days after macrophage infection. MA and MI in infected normal macrophages which were cultured in normal serum replicated in these macrophages at similar rates. MA but not MI multiplied abnormally rapidly in patient macrophages cultured in either normal serum or patient serum. The accelerated growth of MA in patient macrophages was macrophage dependent, because patient sera did not change the rate of MA replication in culture medium lacking macrophages. However, patient sera did increase the permissiveness of normal macrophages to MA but not MI. These results suggest that a selective increased susceptibility to MA compared with a retained normal resistance to MI in human immunodeficiency virus-infected patients as they progress from AIDS-related complex to AIDS accounts for the higher prevalence of MA than MI infection in AIDS patients. The results also indicate that the mechanisms of native resistance in human macrophages to MA and MI are different.

Adult↗
PubMed1990

Carbon fibre composite bone plates. Development, evaluation and early clinical experience.

We compared the mechanical properties of carbon fibre composite bone plates with those of stainless steel and titanium. The composite plates have less stiffness with good fatigue properties. Tissue culture and small animal implantation confirmed the biocompatibility of the material. We also present a preliminary report on the use of the carbon fibre composite plates in 40 forearm fractures. All fractures united, 67% of them showing radiological remodelling within six months. There were no refractures or mechanical failures, but five fractures showed an unexpected reaction; this is discussed.

Adult↗
PubMed1990

Group G streptococcal septic arthritis.

The Lancefield group G streptococcus is known to be a cause of serious infective illness. However, few cases of septic arthritis are recorded. Only one report of this infection, following total joint replacement, has appeared in the orthopaedic literature. Here we describe a further case of infection in a previously normal joint that presented with unusual clinical findings and radiographic changes. We stress the importance of accurate bacteriological investigation and aggressive treatment.

Aged↗
PubMed1989

Development and clinical application of an external fixator monitoring system.

A monitoring system for measuring movement occurring in a dynamic external fixator used to treat fractures is described. The system measures shortening during fracture healing, micromovement at the fracture site on weight bearing and detects pin loosening. The method of calibration including cadaver experiments is presented. The clinical application is described and the reasons for measuring movement are discussed.

Bone Nails↗
PubMed1988

Medullary satiety.

A 62-year-old man with a tegmental medullary glioma lost 30 pounds of weight in several months because of lack of appetite and early satiety. The medullary tegmentum may play an important role in regulating feeding behavior in humans.

Brain Neoplasms↗
PubMed1987

Electroencephalographic activity after brain death.

Fifty-six consecutive patients clinically diagnosed as brain dead were seen at Loyola University Medical Center, Maywood, Ill, from January 1984 through May 1986. Eleven (19.6%) of the 56 patients had electroencephalographic (EEG) activity following the diagnosis of brain death. The mean duration of the observed EEG activity was 36.6 hours (range, two to 168 hours). Three patterns of EEG activity were observed: (1) low-voltage (4 to 20 microV) theta or beta activity was recorded in nine (16.1%) patients as long as 72 hours following brain death. Neuropathologic studies in one patient showed hypoxic-ischemic neuronal changes involving all cell layers of the cerebral cortex, basal ganglia, brain stem, and cerebellum; (2) sleep-like activity (a mixture of synchronous 30 to 40 microV theta and delta activity and 60 to 80 microV, 10 to 12 Hz spindle-like potentials) was noted in two (3.6%) patients for as long as 168 hours following brain death. Pathologic studies in both cases demonstrated ischemic necrosis of the brain stem with relative preservation of the cerebral cortex; and (3) alpha-like activity (monotonous, unreactive, anteriorly predominant, 25 to 40 microV, 9 to 12 Hz activity) was observed in one (1.8%) patient three hours following brain death. Regardless of activity on the EEG, none of the patients recovered. The occurrence of EEG activity following brain death would suggest reliance on the EEG to confirm brain death may be unwarranted. The use of the EEG as a confirmatory test of brain death may be of questionable value.

Brain↗
PubMed1986

Collagen types present at human fracture sites--a preliminary report.

Collagen has been examined from normally and abnormally healing fractures. A higher proportion of type III collagen than was expected was found in abnormally healing fractures. Very little is known about collagen synthesis in healing fractures and how it is altered in abnormal healing states such as delayed and non-union.

Collagen↗
PubMed1986

Intravenous regional anaesthesia for the treatment of upper limb injuries in childhood.

A prospective study was made of the use of intravenous regional anaesthesia for the treatment of upper limb fractures and dislocations in 200 children aged from 3 to 15 years. An aqueous solution containing 5 mg/ml of lignocaine (0.5%) was administered in a dosage of 3 mg/kgm body weight, but dosages of 2 mg/kgm were used in each arm of a child with bilateral injuries. Intravenous regional anaesthesia was well tolerated and was a safe and effective method of treating these injuries in a casualty department with adequate resuscitation facilities and staff trained in the management of local anaesthetic toxicity.

Adolescent↗
PubMed1985

Neuron-specific enolase and neurofilament protein as markers of differentiation in medulloblastoma.

Immunocytochemical localization of neuron-specific enolase was performed attempting evaluation for neuronal cell differentiation in medulloblastoma. Twenty-seven cases of human medulloblastomas were stained with anti-neuron-specific enolase and antineurofilament protein serum using the peroxidase-antiperoxidase technique. All medulloblastomas showed neuron-specific enolase immunoreaction but only few had neurofilament protein-positive cells. These results suggest that a practically universal tendency towards neuronal cell differentiation occurs in medulloblastomas and that synthesis of neuron-specific enolase takes place before sufficient amounts of neurofilament protein are produced to become immunocytochemically detectable.

Cell Transformation, Neoplastic↗