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Biomedical subjects

S Clarke

Publications and source records attributed to S Clarke.

At least 19 recordsLinked to original sources
PubMed2006

Constrained components for the unstable hip following total hip arthroplasty: a literature review.

Patients with chronic instability or late dislocation following total hip arthroplasty often require operative management. Unfortunately, there is an increased risk of recurrent dislocation following revision in these patients. Over the past decade the use of constrained devices for patients with chronic instability has gained increased interest; however, there is a paucity of studies available in the literature regarding the use of these devices. The purpose of this study was to analyze the available literature over the past 15 years, focusing on larger, long-term studies, to obtain recommendations from the respective articles for indications and contraindications for the use of constrained devices. Our review of eight reports included 1,199 hips in 1,148 patients with a total mean follow-up of 51 months (range, 24 to 124 months). The mean rate of dislocation following revision with a constrained liner was 10% and the mean re-operation rate for reasons other than dislocation was 4%. We concluded that constrained liners are an option for patients who have failed management of instability with other implants, those with instability of unclear etiology, those with cognitive problems who are unable to follow dislocation precautions, those with deficient abductors, and elderly or low-demand individuals with well-positioned implants requiring revision.

Arthroplasty, Replacement, Hip↗
PubMed2006

Irofulven as first line therapy in recurrent or metastatic gastric cancer: a phase II multicenter study by the Cancer Therapeutics Research Group (CTRG).

BACKGROUND: The purpose of this study was to evaluate the tolerability and efficacy of irofulven, a DNA interacting acylfulvene analog, as first line therapy for patients with recurrent or metastatic gastric cancer. PATIENTS AND METHODS: Twenty-three patients with recurrent or metastatic gastric cancer received irofulven at a dose of 0.45 mg/kg administered intravenously over 30-min infusion (up to a maximum of 50 mg), on days 1 and 8, every 3 weeks. RESULTS: The median number of cycles delivered per patient was 2 (range 1-6). Two patients (9%) had >or= 1-week delay in administration of subsequent cycle of chemotherapy. For the day 8 chemotherapy, dose reductions were required in seven patients (30%); dose omitting occurred in five patients (22%). Grade 3/4 anemia and neutropenia occurred in 22 and 17% of patients, respectively. There was no grade 4 thrombocytopenia and no neutropenic fever was observed. Of the 20 evaluable patients, there were no responses observed, 3 patients had stable disease after 2 cycles of treatment which was not confirmed by a further assessment. Median overall survival was 6.05 months (95% CI 4.55-9.39). CONCLUSIONS: Irofulven was tolerated at the dose of 0.45 mg/kg on days 1 and 8, every 3 weeks but showed no evidence of antitumor activity in patients with advanced gastric cancer.

Adenocarcinoma↗
PubMed2006

Auditory motion affects visual biological motion processing.

The processing of biological motion is a critical, everyday task performed with remarkable efficiency by human sensory systems. Interest in this ability has focused to a large extent on biological motion processing in the visual modality (see, for example, Cutting, J. E., Moore, C., & Morrison, R. (1988). Masking the motions of human gait. Perception and Psychophysics, 44(4), 339-347). In naturalistic settings, however, it is often the case that biological motion is defined by input to more than one sensory modality. For this reason, here in a series of experiments we investigate behavioural correlates of multisensory, in particular audiovisual, integration in the processing of biological motion cues. More specifically, using a new psychophysical paradigm we investigate the effect of suprathreshold auditory motion on perceptions of visually defined biological motion. Unlike data from previous studies investigating audiovisual integration in linear motion processing [Meyer, G. F. & Wuerger, S. M. (2001). Cross-modal integration of auditory and visual motion signals. Neuroreport, 12(11), 2557-2560; Wuerger, S. M., Hofbauer, M., & Meyer, G. F. (2003). The integration of auditory and motion signals at threshold. Perception and Psychophysics, 65(8), 1188-1196; Alais, D. & Burr, D. (2004). No direction-specific bimodal facilitation for audiovisual motion detection. Cognitive Brain Research, 19, 185-194], we report the existence of direction-selective effects: relative to control (stationary) auditory conditions, auditory motion in the same direction as the visually defined biological motion target increased its detectability, whereas auditory motion in the opposite direction had the inverse effect. Our data suggest these effects do not arise through general shifts in visuo-spatial attention, but instead are a consequence of motion-sensitive, direction-tuned integration mechanisms that are, if not unique to biological visual motion, at least not common to all types of visual motion. Based on these data and evidence from neurophysiological and neuroimaging studies we discuss the neural mechanisms likely to underlie this effect.

Acoustic Stimulation↗
PubMed2006

Role of individualization of hepatitis C virus (HCV) therapy duration in HIV/HCV-coinfected individuals.

OBJECTIVE: The aim of this study was to assess the efficacy, safety and tolerability of pegylated interferon and ribavirin in HIV/hepatitis C virus (HCV)-coinfected patients, prescribed for the same duration and at the same dosage as that used in HCV monoinfection studies. DESIGN: It was an open-label, single-centre, prospective study. METHODS: Forty-five patients coinfected with HIV and HCV with CD4 counts >200 cells/microL were treated with pegylated interferon-alpha2b 1.5 microg/kg/week and ribavirin 1000-1200 mg/day for 24-48 weeks depending on HCV genotype. Safety and tolerability were assessed weekly for the first month and monthly thereafter. Virological response was assessed at weeks 4, 12 and 24 and at the end of treatment and 12 and 24 weeks post completion of treatment. The primary endpoint was defined as undetectable HCV RNA at 24 weeks post completion of treatment [sustained virological response (SVR)]. RESULTS: The majority of patients were male and had been injecting drug users. Sixty per cent were on antiretroviral therapy. In an intention-to-treat analysis, 53% had an SVR (genotype 1, 19% and genotype 2/3, 75%). All patients who had undetectable HCV RNA at week 4 of HCV treatment [very early virological response (VEVR)] had a SVR. On multivariate analysis only HCV genotype predicted SVR. Adverse events occurred frequently. CONCLUSIONS: These results indicate that 24 weeks of HCV treatment may be adequate for HIV-infected individuals coinfected with HCV genotype 2 or 3. VEVR can predict SVR in this group and may be used to guide the subgroup of genotype 2/3 individuals who will respond to 24 weeks of treatment.

Adult↗
PubMed2005

Serum cartilage oligomeric matrix protein and other biomarker profiles in tibiofemoral and patellofemoral osteoarthritis of the knee.

OBJECTIVES: There is some evidence that tibiofemoral osteoarthritis (TFJ OA) and patellofemoral osteoarthritis (PFJ OA) may have different risk factors. To investigate the possibility that these conditions are separate disease entities, we compared biomarker profiles of patients with each disease. METHODS: Serum samples were taken from 222 patients who had knee pain and X-ray signs of knee OA. Eighty-two had only medial TFJ OA and 38 only PFJ OA in one or both knees. The remaining patients had either mixed disease or equivocal radiographic evidence of OA. The following biomarkers were measured in serum samples from baseline and follow-up visits: cartilage oligomeric matrix protein (COMP), glycosaminoglycan, keratan sulphate epitope 5D4, YKL-40, osteocalcin, C-telopeptide of type I collagen, hyaluronan and C-reactive protein. RESULTS: The two subsets of OA (TFJ and PFJ) had similar radiographic disease severity and there were no significant differences in the presence and patterns of pain scores (visual analogue scale and Western Ontario and McMaster Universities Osteoarthritis Index). No difference was found for the biomarkers between the two groups, with one exception. Both baseline and area under the curve per month COMP concentrations were significantly higher in the TFJ than the PFJ group (P<0.01). CONCLUSIONS: The reduced serum COMP in PFJ disease compared with TFJ OA could be due to small articular cartilage volume in the latter or to a qualitative difference in cartilage metabolism.

Aged↗
PubMed2005

Postoperative visual loss following prone spinal surgery.

Postoperative visual loss is a rare but disastrous complication that has an estimated incidence of 0.01-1% after non-ocular surgery. We report a patient who underwent a prolonged spinal operation in the prone position and complained of blindness in one eye postoperatively. We consider the potential aetiological factors contributing to this unilateral postoperative visual loss and suggest strategies to reduce the incidence of this complication in spinal surgery.

Blindness↗
PubMed2005

Survey of psychosocial support provided by UK paediatric oncology centres.

AIM: To obtain a comprehensive overview of current patterns of psychosocial support provided by National Health Service (NHS) paediatric oncology treatment centres across the UK. METHODS: A postal questionnaire was sent to co-ordinators in the UK Children's Cancer Study Group (a professional body that is responsible for the organisation of treatment and management of childhood cancer in the UK) in 21 treatment centres and three separate Teenage Cancer Trus units. A range of psychosocial topics were explored, including ratio of staff providing support to patients; facilities provided for children and families; psychosocial support services such as support groups; information provision; and transition support. RESULTS: There were many good areas of support provided by centres, but there was also a lack of standard practices and procedures. All centres employed social workers, play specialists, and paediatric oncology outreach nurses, but patient to staff ratios varied across centres. The poorest staff provision was among psychologists, where patient to staff ratios ranged from 132:1 to 1100:1. Written information was standard practice, while provision of other types of information (audiovisual, online) varied; none of the centres provided audio information specifically for children/young people. CONCLUSION: This variability in practices among centres frequently occurred, as centres rarely had procedures formally agreed or recorded in writing. British government policy currently seeks to develop standards and guidelines of care throughout the National Health Service. This study further demonstrates the importance of standards and the need to agree guidelines for the provision of psychosocial support for children/young people and their families throughout the course of the illness.

Child↗
PubMed2005

Australian experience of a modified schedule of FOLFOX with high activity and tolerability and improved convenience in untreated metastatic colorectal cancer patients.

This study determined the efficacy and safety of a modified FOLFOX regimen that improved patient convenience without compromising oxaliplatin dose intensity. A total of 62 patients with previously untreated metastatic colorectal cancer were enrolled to receive, entirely as outpatients, 2-weekly cycles of oxaliplatin 100 mg m(-2) i.v. over 2 h, together with leucovorin 400 mg m(-2) over 2 h, 5-fluorouracil (5-FU) 400 mg m(-2), bolus, followed by a 46-h infusion of 5-FU at 2.4 g m(-2). Treatment was given until progression or unmanageable toxicity. In all, 61 patients received > or =one oxaliplatin dose and a median of 11 treatment cycles (range 1-20 cycles); 22 (36%) reported grade 3/4 neutropenia and 13 patients (21%) experienced grade 3 neurotoxicity; 16 patients (26%) discontinued treatment due to disease progression or death, 15 (25%) due to neurotoxicity and six (10%) due to haematological toxicity. Of the 56 eligible patients, complete or partial responses were observed in 29 or 52% (95% confidence interval 38-65%). Median progression-free survival was 8.2 months (7.1-9.9) and median overall survival was 18.7 months (14.0-23.4). In our experience, a modified schedule of FOLFOX improves convenience without compromising efficacy or toxicity.

Adult↗
PubMed2005

Allergic reactions in the community: a questionnaire survey of members of the anaphylaxis campaign.

BACKGROUND: Allergic reactions to food are well recognized in both children and adults, but because of their relative infrequency their typical features may not be readily recognized by patients and their medical care givers who are not allergists. OBJECTIVE: We sought to investigate the circumstances and clinical characteristics of food allergies in adults and children in the community. METHODS: Self-completed questionnaire responses over a 6-month period from 109 members of the Anaphylaxis Campaign, the major British patient resource group for people who have suffered severe allergic reactions. RESULTS: One hundred and nine respondents reported 126 reactions during the study period. Seventy-five were children (under 16 years, median age 6 years at the time of reaction). Predictably more boys than girls were reported to have had reactions but more women reported reactions than men (P<0.05). Although the groups were equally aware of their food allergies the children had undergone diagnostic tests more often (P<0.001). Foods were implicated in 112 (89%) of reports. Restaurants were implicated less often (14%) than in other series, probably reflecting British eating habits. Children with asthma reported more severe reactions than those without asthma (P=0.008), although frequency or severity of recent asthma symptoms was not associated with severity of allergic reaction reported. When available, self-injectable adrenaline was used in 35% of severe reactions and 13% of non-severe reactions (P=0.01). A quarter of adults who received one dose of adrenaline also received a second dose. CONCLUSION: The allergens implicated in this report reflect previous data from similar patient groups in North America. Asthmatic children suffer more severe reactions than non-asthmatic children. It appears that British adults need better access to expert care of their allergies. Even when it is prescribed and available self-injectable adrenaline appears under-used in severe reactions. The incidence of severe but non-fatal allergic reactions in the UK may have been underestimated in the past.

Adolescent↗
PubMed2005

Gefitinib in advanced non-small cell lung cancer.

BACKGROUND: Gefitinib is an oral, selective epidermal growth factor receptor (EGFR) inhibitor that has activity in non-small cell lung cancer (NSCLC). AIM: To evaluate the tolerability, safety-profile and response of single agent gefitinib in patients with advanced stage NSCLC. METHODS: Twenty-seven patients of good performance status with stage IIIB or IV NSCLC were entered on the study at the Sydney Cancer Centre. Gefitinib was prescribed at an oral dose of 250 mg daily, as a continuous dose. Radiological evaluation of indicator lesions occurred at baseline and were repeated every 2-3 months until disease progression. Toxicity was graded using standard measures at baseline and at every month. RESULTS: The response rate was 17% in the patients eligible for evaluation. Symptom improvement was observed in 75% of patients. No patients withdrew because of adverse events. Toxicity was observed in 15 patients and consisted mainly of rash (59%), which was usually mild in severity. CONCLUSION: Gefitinib is active in NSCLC. It is well tolerated with minimal side-effects. Symptomatic improvement was found in the majority of patients treated with gefitinib. There may be a role for gefitinib in the palliation of symptoms in patients with advanced NSCLC.

Adenocarcinoma↗
PubMed2005

Weekly docetaxel as second line treatment after mitozantrone for androgen-independent prostate cancer.

BACKGROUND: Two recent phase III trials have shown an improvement in survival with the use of docetaxel in metastatic androgen-independent prostate cancer (AIPC) compared to mitozantrone. However no phase II trials have clearly defined the level of activity of docetaxel after mitozantrone. AIMS: We sought to define the activity and toxicity of weekly docetaxel as second line chemotherapy after mitozantrone in men with AIPC. METHODS: Twenty men were treated with docetaxel 40 mg/m2 weekly for 3 of every 4 weeks until progression or prohibitive toxicity. End-points included prostate specific antigen response, common toxicity criteria, time to progression and overall survival. RESULTS: Nine patients (45%) had a 50% or greater reduction in PSA maintained for at least 1 month. Weekly docetaxel was well tolerated with few major toxicities: two patients had Grade 3 diarrhoea (10%) and six had grade 2-4 haematologic toxicities (30%). The median time to progression was 5 months (range 0-13) and median survival was 13 months (range 1-24) from starting docetaxel. The median survival from starting mitozantrone was 19 months. Men who had responded to mitozantrone were no more likely to respond to docetaxel (P = 0.2 Fischer's exact test). CONCLUSIONS: Weekly docetaxel is a safe and active second-line treatment after mitozantrone for androgen-resistant prostate cancer, with similar levels of activity to the first-line setting.

Adenocarcinoma↗
PubMed2005

Attention deficit disorder: not just for children.

Abstract Attention deficit/hyperactivity disorder (ADHD) has long been described in children who demonstrate developmentally inappropriate symptoms of inattention, impulsivity and motor restlessness. In adults, symptoms are known to persist and the validity of adult ADHD as an entity is now recognized. There is an associated high proportion of other serious psychiatric comorbidities, especially substance abuse, mood and anxiety disorders. Advances have been made into the aetiology and management of ADHD. Many of these focus on the dopamine and noradrenaline pathways.

Adult↗
PubMed2005

EFNS guidelines on cognitive rehabilitation: report of an EFNS task force.

Disorders of language, spatial perception, attention, memory, calculation and praxis are a frequent consequence of acquired brain damage [in particular, stroke and traumatic brain injury (TBI)] and a major determinant of disability. The rehabilitation of aphasia and, more recently, of other cognitive disorders is an important area of neurological rehabilitation. We report here a review of the available evidence about effectiveness of cognitive rehabilitation. Given the limited number and generally low quality of randomized clinical trials (RCTs) in this area of therapeutic intervention, the Task Force considered, besides the available Cochrane reviews, evidence of lower classes which was critically analysed until a consensus was reached. In particular, we considered evidence from small group or single cases studies including an appropriate statistical evaluation of effect sizes. The general conclusion is that there is evidence to award a grade A, B or C recommendation to some forms of cognitive rehabilitation in patients with neuropsychological deficits in the post-acute stage after a focal brain lesion (stroke, TBI). These include aphasia therapy, rehabilitation of unilateral spatial neglect (ULN), attentional training in the post-acute stage after TBI, the use of electronic memory aids in memory disorders, and the treatment of apraxia with compensatory strategies. There is clearly a need for adequately designed studies in this area, which should take into account specific problems such as patient heterogeneity and treatment standardization.

Advisory Committees↗
PubMed2004

A comparison of the semiflexed (MTP) view with the standing extended view (SEV) in the radiographic assessment of knee osteoarthritis in a busy routine X-ray department.

OBJECTIVE: To compare the reproducibility of the standing extended view (SEV) (also known as the standing anteroposterior view) with the semiflexed, postero-anterior view [the 'metatarsophalangeal' (MTP)] view for assessing joint space width (JSW) and osteophytes in osteoarthritis of the knee when used in a busy routine X-ray department. METHODS: Forty-seven patients (24 men) had both SEV and MTP views taken on the same day in a busy National Health Service radiography department. Repeat views were taken as entirely separate procedures some time over the following 2 weeks, in the same department and with no special arrangements for the selection of radiographers, time of day, or X-ray machine. The first 24 patients had second views in the SEV position whilst the remaining 23 had second MTP views. Radiographs were read independently by two experienced observers who measured JSW with a transparent ruler to the nearest 0.5 mm at the narrowest point in both medial and lateral compartments of the tibiofemoral joint in both knees. Osteophytes were graded 0-2 according to a standard atlas. Ten SEV and 10 MTP radiographs selected randomly were re-read by one observer. RESULTS: Mean (95% confidence interval) JSW in the medial compartment measured on SEV radiographs was 3.54 mm (3.08, 3.99) and on MTP radiographs it was 2.80 mm (2.37, 3.23); in the lateral compartment it was 6.04 mm (5.71, 6.37) when measured on SEV radiographs and 5.47 mm (5.09, 5.85) on MTP radiographs. The estimated variances for the medial compartment were 2.0 mm2 for SEV and 0.2 mm2 for MTP (P < 0.001) and for the lateral compartment 1.4 mm2 for SEV and 0.5 mm2 for MTP (P < 0.001). The proportion of radiographs for which there was disagreement between observers regarding osteophyte grade was not statistically different between SEV and MTP views (SEV, medial 40%, lateral 44%; MTP, medial 39%, lateral 39%). CONCLUSIONS: Even when radiographs are taken in a busy National Health Service radiography department, measurement of JSW from the MTP view is more reproducible than from the SEV view, the MTP view gives a slightly lower measurement of JSW, and there is no advantage in using either view in recording osteophyte grade. We recommend the wider adoption of the MTP method.

Arthrography↗
PubMed2004

Dual-energy X-ray absorptiometry applied to the assessment of tibial subchondral bone mineral density in osteoarthritis of the knee.

OBJECTIVE: Plain X-ray is an imprecise tool for monitoring the subchondral bony changes associated with the development of knee osteoarthritis (OA). Our objective was to develop and validate a technique for assessing tibial subchondral bone density (BMD) in knee OA using dual energy X-ray absorptiometry (DXA). DESIGN: Patients with OA of at least one knee underwent DXA scanning of both knees. Regions of interest (ROI) were placed in the lateral and medial compartments of tibial subchondral bone. Weight-bearing plain X-rays and Te (99m) scintiscans of both knees were obtained and scored. RESULTS: One hundred and twelve patients (223 knees) underwent DXA and radiography. Intra-observer CV% was 2.4% and 1.0% for the medial and lateral ROI respectively. Definite OA (Kellgren and Lawrence Grade 2, 3 or 4) was correlated with age-related preservation of subchondral BMD compared to radiographically normal knees. Raised BMD was also associated with subchondral sclerosis, and positive scintigraphy. CONCLUSION: DXA may provide a safe, rapid and reliable means of assessing knee OA. Cross-sectional age-related subchondral tibial BMD loss is attenuated by knee OA.

Absorptiometry, Photon↗