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Biomedical subjects

R Quirk

Publications and source records attributed to R Quirk.

13 recordsLinked to original sources
PubMed2005

Five additional mobility and locomotor items to improve responsiveness of the FIM in wheelchair-dependent individuals with spinal cord injury.

STUDY DESIGN: Repeated-measures design. OBJECTIVES: To assess the validity and responsiveness of five additional mobility and locomotor (5-AML) items when used in conjunction with the Functional Independence Measure (FIM) for assessing the mobility and locomotor function of individuals with spinal cord injury (SCI). SETTING: Specialised acute spinal and rehabilitation units in Sydney, Australia. METHODS: A previously published scale comprising five key mobility and locomotor skills was further refined. The five items included a bed mobility and vertical (floor-to-chair) transfer item and three wheelchair propulsion items (pushing 200 m over flat ground, pushing up a ramp and negotiating a kerb). A total of 43 eligible patients with SCI (ASIA A-C impairment) admitted consecutively to two acute SCI units in Sydney between 1999 and 2002 were recruited, with four being lost to follow-up. Locomotor and mobility outcomes were measured at regular intervals for up to 6 months with the FIM and the 5-AML. Construct validity of the 5-AML was assessed by testing ability of items to discriminate between different impairment groups (tetraplegia and paraplegia). Item responsiveness was assessed by analysing ability to detect changes in mobility and locomotor function over time. Factor analysis techniques were used to test the hypothesis that the 5-AML, when used in conjunction with the FIM, provides a more sensitive measure of mobility and locomotor function than the FIM alone. RESULTS: The 5-AML items were shown to be valid and responsive, measuring aspects of 'real world' mobility and locomotor function not reflected by the FIM. The bed mobility item was highly responsive to change over time for the tetraplegic group, but quickly reached a ceiling in the paraplegic group. The vertical (floor-to-chair) transfer item showed greater responsiveness over time and less ceiling effect for the paraplegic group than any of the FIM locomotor or mobility items. The three wheelchair propulsion items better discriminated between people with tetraplegia and paraplegia, and were more sensitive to changes in locomotor ability over the 6-month period than FIM locomotor items. Results of a preliminary factor analysis indicated that the 5-AML items measure different aspects of mobility and locomotor function than the FIM. CONCLUSION: The 5-AML items, when used in conjunction with the FIM, provides better delineation of function between people with tetraplegia and paraplegia and provides a more responsive measure of change in function over time than the FIM alone.

Activities of Daily Living↗
PubMed2001

Human osteoprogenitor growth and differentiation on synthetic biodegradable structures after surface modification.

The ability to generate new bone for skeletal use is a major clinical need. Biomimetic scaffolds that interact and promote osteoblast differentiation and osteogenesis offer a promising approach to the generation of skeletal tissue to resolve this major health-care issue. In this study we examine the ability of surface-modified poly(lactic acid) (PLA) films and poly(lactic-co-/glycolic acid) (PLGA) (75:25) porous structures to promote human osteoprogenitor adhesion, spreading, growth, and differentiation. Cell spreading and adhesion were examined using Cell Tracker green fluorescence and confocal microscopy. Osteogenic differentiation was confirmed with alkaline phosphatase activity as well as immunocytochemistry for type I collagen, core binding factor-1 (Cbfa-1), and osteocalcin. Poor cell growth was observed on nonmodified PLA films and PLGA scaffolds. The polymers were then coupled with RGD peptides [using poly(L-lysine), or PLL] and physical adsorption as well as PLA films presenting adsorbed fibronectin (FN). Both modifications enhanced cell attachment and spreading. On PLA-FN and PLA-PLL-GRGDS films, the osteoblast response was dose dependent (20 pmol/L to 0.2 micromol/L FN and 30 nmol/L to 30 micromol/L PLL-GRGDS) and significant at concentrations as low as 2 nmol/L FN and 30 nmol/L PLL-GRGDS. With optimal concentrations of FN or RGD, adhesion and cell spreading were comparable to tissue culture plastic serum controls. In PLGA (75:25) biodegradable porous scaffolds, coated with FN, PLL-GRGDS, or fetal calf serum for 24 h in alpha MEM alone, prior to growth in dexamethasone and ascorbate-2-phosphate for 4-6 weeks, extensive osteoblast impregnation was observed by confocal and fluorescence microscopy. Cell viability in extended culture was maintained as analyzed by expression of Cell Tracker green and negligible ethidium homodimer-1 (a marker of cell necrosis) staining. Alkaline phosphatase activity, type I collagen, Cbfa-1, and osteocalcin expression were observed by immunocytochemistry. Mineralization of collagenous matrix took place after 4 weeks, which confirmed the expression of the mature osteogenic phenotype. These observations demonstrate successful adhesion and growth of human osteoprogenitors on protein- and peptide-coupled polymer films as well as migration, expansion, and differentiation on three-dimensional biodegradable PLGA scaffolds. The use of peptides/proteins and three-dimensional structures that provide positional and environmental information indicate the potential for biomimetic structures coupled with appropriate factors in the development of protocols for de novo bone formation.

Aged↗
PubMed1996

Metatarsalgia.

Metatarsalgia, or pain in the metatarsal region of the foot, is a common orthopaedic problem, but is generally less well understood than pain in the toes, ankle or heel. The cause of metatarsal pain is often less apparent than in other regions of the foot, and in many cases plain X-rays are of no help. Morton's neuroma, a common cause of severe metatarsalgia, can usually only be diagnosed from the history and clinical examination. The key to diagnosis in the metatarsal region is to have a clear knowledge of the most likely conditions.

Diagnosis, Differential↗
PubMed1994

Common foot and ankle injuries in dance.

Classical ballet is a popular but physically demanding activity. Minor injuries become increasingly common as the dancer encounters the greater workload of professional dancing. The doctor must have a basic knowledge of ballet technique and an understanding of the mental approach of dancers to accurately diagnose and effectively treat their injuries. The practice of dancing on the toes, the exaggerated turn out of the feet, and the extreme flexibility of the hips and spine all lead to unusual injuries. With informed conservative treatment, most ballet injuries will heal, but surgery is occasionally required.

Achilles Tendon↗
PubMed1993

Stress fractures.

Stress fractures are now common. They are often missed because the doctor fails to keep the possible diagnosis in mind, or believes that a plain X-ray can exclude these fractures. A bone scan gives the diagnosis. Treatment is by rest in most cases, but stress fractures of the navicular sometimes require surgery.

Athletic Injuries↗
PubMed1990

Phenylpropanolamine and caffeine use among diet center clients.

We surveyed phenylpropanolamine (PPA) use and overuse among 309 diet center clients. Fifty-one percent of all subjects surveyed reported using PPA drugs: 44 percent used cold medicines and 16 percent used diet aids. Twenty-two percent of diet aid users and 7 percent of cold medicine users reported that they deliberately used more than the dosage recommended to improve efficacy. Among diet aid users, 59 percent also regularly consumed caffeine. Despite package warnings, individuals who had been told by their doctors that they were hypertensive used PPA products as often as normotensive individuals. PPA, the fifth most frequently used drug in the USA, is contained in over-the-counter (OTC) diet aids as well as OTC and prescription cold medicines. Severe adverse drug reactions (ADRs) including hypertensive crisis, stroke and death have been attributed to PPA products. Clinical studies have shown that using greater than recommended doses of PPA and using PPA in combination with caffeine may increase the risk of ADRs. Overweight patients may be particularly at risk for ADRs to PPA because they are likely to be hypertensive and to use diet aids. We recommend informing diet center clients of the potential dangers of consuming PPA products, especially more than the recommended dose, in the presence of hypertension, and when other sympathomimetic drugs are being taken.

Adult↗
PubMed1988

The effects of phenylpropanolamine on human sympathetic nervous system function.

Phenylpropanolamine (PPA) is a sympathomimetic agent, very similar in structure to amphetamine. In the United States, it is present in over 130 medications, primarily anorectic agents and cough and cold remedies, many available without a prescription. The effects of PPA on blood pressure (BP) remain controversial and its mechanisms of action unknown. We studied acute (1 and 2 hours) and 2-week effects of a daily dose of 75 mg of sustained release PPA administered to 14 normal volunteers. Measurements of heart rate, BP, and plasma catecholamines (CA) were made with the subject in the supine and standing positions, and upon gripping a hand dynamometer for 5 minutes. Although systolic BP across all postures and sampling times was significantly higher when subjects were taking PPA in comparison to placebo (F = 5.95, p = 0.03), in no subject did the increase in BP reach hypertensive or clinically significant levels and no substantial changes in CA levels were found. Our study population was relatively young and normotensive; even such a small BP increase may pose greater problems for hypertensive, obese subjects likely to be users of diet aids. Strenuous isometric exercise did not cause any greater increase in BP or CA after subjects took PPA versus placebo. PPA blood levels 24 hours after the last of 14 daily doses were similar to levels 1 and 2 hours after an initial dose. We conclude from these data that recommended doses of PPA have only minimal sympathetic nervous system (SNS) and cardiovascular effects in young, healthy, normotensive populations at the times and dose studied.

Adult↗
PubMed1987

Morton's neuroma.

Explore the source record for details and available documents.

Foot Diseases↗
PubMed1984

Injuries in classical ballet.

The specialised medical knowledge about dancers' injuries is negligible compared with that which surrounds sports medicine. The author discusses his experience in the management of more than 2000 injuries sustained by dancers of classical ballet.

Adolescent↗
PubMed1983

Ballet injuries: the Australian experience.

There is a distinct difference between ballet injuries and sports injuries in general, and the sports medicine physician needs to study the technique of dance and the specific injuries that it may produce in order to treat dancers effectively. In Australia, which is typical of other countries where ballet is performed, ballet injuries include strained lumbar muscles, sprained ankle, Achilles tendinitis, clicking hip, jumper's knee, chondromalacia, stress fractures, patellar subluxation, and other knee and tendon problems.

Australia↗