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Biomedical subjects

J Perry

Publications and source records attributed to J Perry.

At least 73 records · Page 4Linked to original sources
PubMed1999

The influence of patellofemoral pain on lower limb loading during gait.

OBJECTIVE: To determine if subjects with patellofemoral pain demonstrate excessive lower limb loading during gait. DESIGN: Prospective study utilizing a group of patients with patellofemoral pain and a control group. BACKGROUND: Increased rate of lower limb loading has been hypothesized as being contributory to knee osteoarthritis and may be the result of decreased knee flexion during weight acceptance. Since patients with patellofemoral pain have been reported to limit knee flexion during gait, these individuals may be at risk for the adverse effects of impulse loading. METHODS: Force plate parameters, lower extremity kinematics and stride characteristics were recorded in 15 females with patellofemoral pain and 10 pain-free controls during self-selected free and fast walking velocities. RESULTS: Individuals in the patellofemoral pain group demonstrated a significantly slower gait velocity during the free and fast trials as well as decreased stance phase knee flexion during fast walking. The average peak loading rate for the patellofemoral pain group was significantly less than the control group during both free (P=0.004) and fast walking (P=0. 03). CONCLUSIONS: Despite diminished stance phase knee flexion during fast walking, subjects with patellofemoral pain did not demonstrate increased lower limb loading. During gait, the ground reaction forces appeared to be minimized by adopting a slower walking velocity. RELEVANCE: These results indicate that altered knee kinematics as a result of patellofemoral pain do not place these individuals at risk for the adverse effects of impulse loading.

Adolescent↗
PubMed1999

Three dimensional upper extremity motion during manual wheelchair propulsion in men with different levels of spinal cord injury.

This investigation compared three dimensional upper extremity motion during wheelchair propulsion in persons with 4 levels of spinal cord injury: low paraplegia (n=17), high paraplegia (n=19), C7 tetraplegia (n=16), and C6 tetraplegia (n=17). Upper extremity motion was recorded as subjects manually propelled a wheelchair mounted on a stationary ergometer. For all motions measured, subjects with paraplegia had similar patterns suggesting that the wheelchair backrest adequately stabilizes the trunk in the absence of abdominal musculature. Compared with paraplegic subjects, those with tetraplegia differed primarily in the strategy used to contact the wheel. This was most evident among subjects with C6 tetraplegia who had greater wrist extension and less forearm pronation.

Adult↗
PubMed1999

JC and BK virus sequences are not detectable in leukaemic samples from children with common acute lymphoblastic leukaemia.

Epidemiological evidence suggests that childhood leukaemia, and possibly common acute lymphoblastic leukaemia in particular, may have an infectious aetiology. Smith (1997 J Immunother 20: 89-100) recently suggested that the critical infectious event occurs during pregnancy, and identified the polyoma virus JC as a candidate agent. In the present study we investigated whether genomes from the JC virus, and closely related BK virus, could be detected in leukaemic cells. No positive results were obtained suggesting that JC virus is unlikely to play a direct role in leukaemogenesis.

BK Virus↗
PubMed1999

Opportunity and the promotion of activity among adults with severe intellectual disability living in community residences: the impact of training staff in active support.

Active support, a package of procedures which includes activity planning, support planning and training on providing effective assistance, was introduced in five community residences serving 19 adults with severe intellectual disability following a multiple baseline design. The residents were directly observed to ascertain the level of assistance they received from staff and their engagement in activity. The introduction of active support increased the levels of assistance residents received, their engagement in domestic activities and their total engagement in activity. The intervention did not affect the level of social engagement. Across individuals, increases in assistance and engagement in activity were significantly and positively correlated. Both were significantly inversely related to resident adaptive behaviour. At baseline, staff gave more attention and assistance to people who were behaviourally more able. After the introduction of active support, receipt of attention was unrelated to adaptive behaviour and the behaviourally less able received more assistance. The disparity in activity between the more and less able was reduced. Gains were maintained in the majority of houses.

Activities of Daily Living↗
PubMed1999

The use of gait analysis for surgical recommendations in traumatic brain injury.

Traumatic brain injury causes unpredictable errors in the patient's gait by introducing varying mixtures of spasticity, contractures, primitive flexion and extension synergies, and impaired selective control. Surgical release or transfer of the offending muscles can improve the patient's ability to walk if functional errors have been accurately identified. While clinical testing is inadequate, instrumented motion analysis and dynamic electromyography can supply an accurate definition of the abnormalities in muscle action and provide guidelines for distinguishing local from referred motion errors. Examples of the diagnostic differences related to the equinovarus foot and the common types of knee dysfunction are presented.

Brain Injuries↗
PubMed1999

After the stick.

Explore the source record for details and available documents.

Centers for Disease Control and Prevention, U.S.↗
PubMed1999

Relationship between foot pronation and rotation of the tibia and femur during walking.

The purpose of this study was to test the hypothesis that the magnitude and timing of peak foot pronation would be predictive of the magnitude and timing of peak rotation of tibia and femur. Thirty subjects who demonstrated a wide range of pronation participated. Three-dimensional kinematics of the foot, tibia, and femur segments were recorded during self-selected free walking trials using a six-camera VICON motion analysis system. Regression analysis demonstrated that the magnitude and timing of peak pronation was not predictive of the magnitude and timing of tibial and femoral rotation. The lack of a relationship between peak foot pronation and the rotation of the tibia and femur is contrary to the clinical hypothesis that increased pronation results in greater lower extremity rotation. It would seem, therefore, that the relationship between foot pronation and rotation of the lower extremity segments should be assessed on a patient-by-patient basis.

Adult↗
PubMed1999

The hPMS2 exon 5 mutation and malignant glioma. Case report.

Patients with Turcot syndrome (TS) are predisposed to colon tumors and primary brain tumors, typically glioblastomas or medulloblastomas. The authors describe a patient with TS featuring a known germline mutation of exon 5 of the hPMS2 mismatch repair gene who developed two metachronous glioblastomas, both with distinct oligodendroglial features. Molecular genetic analysis revealed allelic loss of chromosome 19q in the patient's second tumor but no allelic loss of chromosome 1p. Prominent microsatellite instability was also found in this tumor, consistent with a germline mismatch repair defect. Because this patient had an unusual underlying condition and his tumor had a unique histological appearance for TS, it was hypothesized that this genetic defect may predispose to malignant gliomas with oligodendroglial features. The authors therefore evaluated whether sporadic glioblastomas and oligodendrogliomas undergo mutations of this region of the hPMS2 gene. However, single-strand conformation polymorphism analysis of hPMS2 exon 5 failed to reveal mutations in 20 sporadic glioblastomas and 16 sporadic oligodendroglial gliomas. Thus, although it is possible that the germline hPMS2 exon 5 mutation may predispose to glioblastomas with an oligodendroglial component, the same genetic defect is not commonly involved in sporadic oligodendrogliomas or glioblastomas.

Adenomatous Polyposis Coli↗
PubMed1998

Patchy fur, a mouse coat mutation associated with X-Y nondisjunction, maps to the pseudoautosomal boundary region.

Patchy fur is a semidominant X-linked mutation in the mouse, resulting in a sparse coat. The Paf mutation also alters the normal segregation of the X and the Y chromosomes during male meiosis by causing nondisjunction at anaphase I. Analysis of 1139 female meioses from an intersubspecific backcross using 15 PCR-based markers localizes Paf to an approximately 0.2-cM interval that includes the pseudoautosomal boundary. The meiotic nondisjunction phenotype may result from a chromosomal rearrangement that includes pseudoautosomal sequences and affects XY pairing.

Animals↗
PubMed1998

Knee kinetics in trans-tibial amputee gait.

This study evaluated the mechanics of the knee during gait in persons with trans-tibial amputations. Spatiotemporal, kinematic, kinetic, and electromyographic data (EMG) were collected from ten individuals with trans-tibial amputations and ten control subjects during level walking. Results found that the trans-tibial amputee (TTA) group had significantly greater EMG activity of the knee extensors and knee flexors compared to normal. The muscle action of the TTA group was inconsistent with the knee kinetic data as demonstrated by a minimal external knee flexion moment and negligible knee power. The discrepancy between the mechanical and physiological measures of knee demand in this population illustrates the need for an integrated approach for the study of joint function during gait (i.e. EMG in combination with kinetic measures). Copyright 1998 Elsevier Science B.V.

Journal Article↗
PubMed1998

Failure load of acrylic resin denture teeth bonded to high impact acrylic resins.

STATEMENT OF PROBLEM: Techniques for bonding denture teeth to an acrylic resin denture base remain empirical, with little consensus from the literature, among clinicians, or among dental laboratories. PURPOSE: This study evaluated the failure load of acrylic resin teeth bonded to 2 high impact acrylic resins. METHODS AND MATERIAL: The ridge lap portion on 120 identical denture teeth were modified with 3 variables: (1) placing a diatoric, (2) using monomer to prewet the denture tooth, and (3) breaking the glaze. Variables were combined to form 6 groups of 10 teeth each, and processed with Lucitone 199 (Lucitone) or SR-Ivocap (Ivocap) acrylic resin. Data analysis included the use of a heterogeneous variance linear regression model. RESULTS: Mean (+/- SD) failure load ranged between 10.25 +/- 1.48 Kg to 28.43 +/- 11.05 Kg for the 6 Ivocap groups and 16.63 +/- 5.87 Kg to 28.05 +/- 5.35 Kg for the Lucitone groups. For Lucitone 199 acrylic resin, the highest failure loads resulted when the ridge lap was left with an intact glaze and did not have a diatoric, with no significant influence from the use of monomer. For Ivocap resin, the highest failure loads resulted when the ridge lap had a diatoric but did not have monomer placed, with no significant influence from glaze. CONCLUSION: Failure load of bonding highly cross-linked denture teeth to SR-Ivocap or Lucitone 199 acrylic resin was significantly influenced by modifications to the ridge lap before processing.

Acrylic Resins↗