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Biomedical subjects

J Roberts

Publications and source records attributed to J Roberts.

At least 19 recordsLinked to original sources
PubMed2006

Developments in clinical islet, liver thoracic, kidney and pancreas transplantation in the last 5 years.

Although organ transplantation has matured into a proven therapy for end-stage organ failure, the many notable developments of the past 5 years speak to the multitude of remaining challenges. Two new procedures, islet transplantation and adult-to-adult living donor liver transplantation, have emerged to enlarge our therapeutic armamentarium for Type 1 diabetes mellitus and end-stage liver disease, respectively. In cardiac transplantation, the acceptance of ventricular assist devices as destination therapy is a notable event in light of critical shortage of deceased donor organs. Both liver and lung allocation policies have made a dramatic paradigm shift away from waiting time toward the survival benefit of transplantation. Finally, primary threats to post-transplant longevity have gained an increasing share of the spotlight. Recognition of the impact of renal insufficiency for all nonrenal transplant recipients, of recurrent hepatitis C virus for liver recipients, and of accelerated vasculopathy for cardiac have identified novel end points for clinical trials.

Graft Survival↗
PubMed2006

Reduction in wound infection rates by wound surveillance with postdischarge follow-up and feedback.

BACKGROUND: Surgical wound surveillance with postdischarge follow-up is rarely done in the UK as it is seen as expensive. The aim of this study was to determine whether employing a dedicated team was effective and reduced costs. METHODS: Infection data were collected prospectively with postdischarge follow-up at 2-3 months, and fed back to surgeons. Wound infection was defined using both ASEPSIS wound scoring and criteria of the US Centers for Disease Control (CDC) definitions. RESULTS: Over 4 years, 15 548 patient episodes were included. Postdischarge surveillance data were available for 79.9 per cent of the 15 154 records of patients who survived. There was a significant reduction in the rate of wound infection between the first and fourth years by ASEPSIS and CDC definitions: odds ratio 0.77 (95 per cent confidence interval (c.i.) 0.64 to 0.92) and 0.69 (95 per cent c.i. 0.57 to 0.83), respectively. The proportion of infections fell significantly in orthopaedic, cardiac and thoracic surgery. The annual budget for wound surveillance was pound 91,600. Changes in infection rates contributed pound 347,491 to the reduction in cost among the patients surveyed. CONCLUSION: Wound surveillance was associated with a reduction in rates of wound infection within 4 years. The cost reduction as a result of fewer infections exceeded the cost of surveillance after 2 years.

Cost-Benefit Analysis↗
PubMed2006

Microscopic polyarteritis presenting with skin necrosis in a patient with sickle-cell disease.

A 20-year-old Caribbean woman with sickle cell anaemia was admitted with a 4-day history of fever and a painful swollen right ankle. She rapidly developed skin necrosis. The differential diagnosis is discussed. This case illustrates the difficulty in identifying the cause of cutaneous necrosis in an acutely ill patient. In our patient, histopathology implicated a vasculitic process, which was subsequently identified as a manifestation of microscopic polyarteritis.

Adult↗
PubMed2006

Peri-prosthetic bone mineral density after total knee arthroplasty. Cemented versus cementless fixation.

We compared peri-prosthetic bone mineral density between identical cemented and cementless LCS rotating platform total knee arthroplasties. Two matched cohorts had dual energy x-ray absorptiometry scans two years post-operatively using a modified validated densitometric analysis protocol, to assess peri-prosthetic bone mineral density. The knee that was not operated on was also scanned to enable the calculation of a relative bone mineral density difference. Oxford Knee and American Knee Society scores were comparable in the two cohorts. Statistical analysis revealed no significant difference in absolute, or relative peri-prosthetic bone mineral density with respect to the method of fixation. However, the femoral peri-prosthetic bone mineral density and relative bone mineral density difference were significantly decreased, irrespective of the method of fixation, particularly in the anterior distal portion of the femur, with a mean reduction in relative bone mineral density difference of 27%. There was no difference in clinical outcome between the cemented and cementless LCS total knee arthroplasty. However, both produce stress-shielding around the femoral implants. This leads us to question the use of more expensive cementless total knee components.

Absorptiometry, Photon↗
PubMed2006

Health benefits of antiviral therapy for mild chronic hepatitis C: randomised controlled trial and economic evaluation.

OBJECTIVES: To determine whether combined therapy with interferon-alpha and ribavirin was more effective and cost-effective than no treatment for patients with mild chronic hepatitis C. DESIGN: A multicentre, randomised, controlled, non-blinded trial assessed the efficacy of combination therapy. A Markov model used these efficacy data combined with data on transition probabilities, costs and health-related quality of life (HRQoL) to assess the lifetime cost-effectiveness of the intervention. SETTING: A multicentre NHS setting. PARTICIPANTS: Treatment-naive, adult patients with histologically mild chronic hepatitis C (Ishak necroinflammatory scores <4 and fibrosis scores <3 on liver biopsy). INTERVENTIONS: Patients were randomised to receive interferon-alpha and ribavirin for 48 weeks or no treatment (control). MAIN OUTCOME MEASURES: The primary outcome measure was the proportion of patients having a sustained virological response (SVR), measured at 6 months after cessation of therapy. Secondary outcome measures were: the ability of early phase kinetics to predict the eventual outcome of treating mild disease; HRQoL measured using the Short Form 36 and EuroQol (5 Dimensions) questionnaires, and the cost per quality-adjusted life-year (QALY) of interferon-alpha and ribavirin for mild disease compared with no treatment. RESULTS: In the treatment group, 32 out of 98 patients (33%) achieved an SVR. Patients infected with genotype 1 had a lower SVR than those infected with genotype non-1 (18% versus 49%, p = 0.02). No patients who failed to achieve a 2-log drop in viral load at 12 weeks achieved an SVR. HRQoL fell during treatment and rose with treatment cessation. For patients having an SVR there were modest improvements in HRQoL at 6 months post-treatment. The mean cost per QALY gained was 4535 pounds sterling for 40-year-old patients with genotype non-1 and 25,188 pounds sterling for patients with genotype 1. For patients with genotype 1 aged 65, providing interferon-alpha and ribavirin for mild disease led to fewer QALYs gained, and a mean cost per QALY of 53,017 pounds sterling. The model using efficacy estimates from the literature, showed that the cost per QALY gained from providing pegylated interferon alpha-2b and ribavirin at a mild stage rather than a moderate stage was 7821 pounds sterling for patients with genotype non-1 and 28,409 pounds sterling for patients with genotype 1. CONCLUSIONS: Based on the evidence collected in this study, interferon-alpha and ribavirin treatment for mild chronic hepatitis C patients is in general cost-effective at the 30,000 pounds sterling per QALY threshold previously used by policy-makers in the NHS. For patients with chronic hepatitis C aged 65 or over with genotype 1, antiviral treatment at a mild stage does not appear cost-effective. Further research is required on the cost-effectiveness of pegylated interferon and ribavirin, in particular the intervention's long-term impact on HRQoL and health service costs requires further evaluation. Further research is also needed to develop predictive tests, based on pharmacogenomics, that can identify those cases most likely to respond to antiviral therapy. Liver biopsy before treatment no longer appears justified apart from for older patients (aged 65 or over) with genotype 1. However, further research should monitor the impact this strategy would have on costs and outcomes.

Adult↗
PubMed2005

Cost effectiveness of interferon alpha or peginterferon alpha with ribavirin for histologically mild chronic hepatitis C.

BACKGROUND: For patients with mild chronic hepatitis C the cost effectiveness of antiviral therapy is unknown. AIMS: To assess whether antiviral therapy (either interferon alpha or peginterferon alpha combined with ribavirin) is cost effective at a mild stage compared with waiting and only treating those cases who progress to moderate disease. PATIENTS: Cases with mild chronic hepatitis C. METHODS: A cost effectiveness model which estimates long term costs and outcomes for patients with mild chronic hepatitis C. The model uses effectiveness and cost data from the UK mild hepatitis C randomised controlled trial, combined with estimates of disease progression and cost from observational studies. RESULTS: Antiviral treatment at a mild rather than a moderate stage improved outcomes measured by quality adjusted life years (QALYS) gained. The mean cost per QALY gained from antiviral treatment with interferon alpha-2b and ribavirin, compared with no treatment at a mild stage, was 4535 pounds sterling (7108 dollars) for patients with genotype non-1 and 25,188 pounds sterling (39,480 dollars) for patients with genotype 1. Providing peginterferon alpha-2b and ribavirin at a mild rather than a moderate stage was also associated with a gain in QALYS; the costs per QALY gained were 7821 pounds sterling (12,259 dollars) for patients with genotype non-1 and 28,409 pounds sterling (44,528 dollars) for patients with genotype 1. CONCLUSIONS: For patients with chronic hepatitis C, it is generally more cost effective to provide antiviral treatment at a mild rather than a moderate disease stage. For older patients (aged 65 years or over) with genotype 1, antiviral treatment at a mild stage is not cost effective.

Adult↗
PubMed2005

Potential toxicity.

Explore the source record for details and available documents.

Aluminum Compounds↗
PubMed2005

Views of UK melanoma patients on routine follow-up care.

Although the need for melanoma follow-up is universally accepted, there is still much debate on the duration and frequency of appointments. The UK guidelines were revised in June 2002 to streamline melanoma follow-up. Following the change in protocol, some of our patients expressed concern at the shorter duration of follow-up. We therefore polled all our active melanoma patients to obtain their views on the outpatient clinics. In particular we asked whether they would be happy to have routine follow-up in a primary care setting. In conjunction with the department of psychology, a short questionnaire was devised assessing patient satisfaction and concerns about follow-up. This was sent to all active melanoma patients in our trust. Out of 304 eligible patients currently attending outpatients, 231 (76%) completed replies were received. Ninety-eight percent of respondents found the clinics to be useful. Twenty two and a half percent felt it was difficult to attend the clinic and this was mainly due to logistical problems, i.e. hospital car parking. The majority were reassured by the clinic visits and felt it was a chance to ask questions and check for new disease. Of the 12% of respondents who had a recurrence, 52% indicated that they had detected it themselves. Sixty percent of patients would be happy to consider routine follow-up with their GP, provided they were suitably experienced and trained. A survey of 50 local GP's found that 70% would be unhappy to monitor their patients. Patients want and benefit from follow-up. However, they are an increasing burden on outpatient clinics, given the increasing incidence of melanoma. GP follow-up may be appropriate for a small subgroup of patients. This combined with shared care and practice based clinical nurse specialists may be the way forward in melanoma follow-up.

Adult↗
PubMed2005

Pathways of care and resource utilization in a national cohort of patients with transfusion-acquired hepatitis C.

The Hepatitis C Strategy and Action Plan for England recommend that all individuals testing positive for hepatitis C virus (HCV) should be referred to a specialist centre for assessment and care. One key aim is to reduce the number of people progressing to liver disease and therefore reduce the associated costs. The aims of this paper are to describe the care pathways and evaluate resource utilization in a cohort of 826 patients with transfusion-acquired hepatitis C enrolled in the HCV national register. We reviewed data extracted from patient notes to establish pathways of care since HCV-positive diagnosis through to May 2002, and to document all treatment, liver biopsy and hospital usage for each patient. Type of care was classified into specialist-interest in HCV-related care, other-hospital care or general practitioner (GP)-led care. Over 70% of patients were referred to specialist care following HCV diagnosis. Patients who were older or who had normal liver function were less likely to be referred to specialist-care. Between first diagnosis and May 2002, no patients were referred from GP to specialist-care. Less than half of this cohort had undergone liver biopsy and only 18% had been treated. Younger patients and those with abnormal liver function were more likely to have undergone liver biopsy and to have received treatment. Analysis of care histories of patients with transfusion-acquired hepatitis C suggest that changes are needed in the care and management of patients with HCV infection, if the recommendations of the HCV strategy and action plan are to be fully implemented.

Adult↗
PubMed2005

The effect of a calcium carbonate/perlite toothpaste on the removal of extrinsic tooth stain in two weeks.

OBJECTIVE: To assess the effect of a calcium carbonate/perlite toothpaste on the levels of extrinsic stain removed at two weeks compared to a silica control toothpaste. DESIGN: In this parallel group, double-blind study, subjects were stratified by natural baseline stain and tobacco use and allocated at random to one of the two study toothpastes. Subjects brushed with their allocated toothpaste twice daily for two weeks before extrinsic tooth stain was again assessed. SETTING: The study was performed at 4-Front Research UK Limited, Maldon, UK. PARTICIPANTS: 152 adult subjects with at least eight assessable incisors/ canines with natural extrinsic tooth stain completed the study. METHODS: The extrinsic tooth stain on the facial surfaces of incisors and canines was measured using the Macpherson modification of the Lobene Stain Index. RESULTS: Both of the toothpaste groups had significantly less stain after two weeks of use compared to the baseline value (p<0.001). Analysis of covariance on the sum of the whole mouth stain scores showed that the calcium carbonate/perlite toothpaste removed significantly more stain over the two week study than the silica control toothpaste (p<0.05). CONCLUSIONS: Twice daily brushing for two weeks with a calcium carbonate/perlite toothpaste removes more extrinsic stain than a silica control toothpaste.

Adolescent↗
PubMed2005

Regulation of vascular endothelial growth factor bioactivity in patients with acute lung injury.

BACKGROUND: Reduced bioactive vascular endothelial growth factor (VEGF) has been demonstrated in several inflammatory lung conditions including the acute respiratory distress syndrome (ARDS). sVEGFR-1, a soluble form of VEGF-1 receptor, is a potent natural inhibitor of VEGF. We hypothesised that sVEGFR-1 plays an important role in the regulation of the bioactivity of VEGF within the lung in patients with ARDS. METHODS: Forty one patients with ARDS, 12 at risk of developing ARDS, and 16 normal controls were studied. Bioactive VEGF, total VEGF, and sVEGFR-1 were measured by ELISA in plasma and bronchoalveolar lavage (BAL) fluid. Reverse transcriptase polymerase chain reaction for sVEGFR-1 was performed on BAL cells. RESULTS: sVEGFR-1 was detectable in the BAL fluid of 48% (20/41) of patients with early ARDS (1.4-54.8 ng/ml epithelial lining fluid (ELF)) compared with 8% (1/12) at risk patients (p = 0.017) and none of the normal controls (p = 0.002). By day 4 sVEGFR-1 was detectable in only 2/18 ARDS patients (p = 0.008). Patients with detectable sVEGFR-1 had lower ELF median (IQR) levels of bioactive VEGF than those without detectable sVEGFR-1 (1415.2 (474.9-3192) pg/ml v 4761 (1349-7596.6) pg/ml, median difference 3346 pg/ml (95% CI 305.1 to 14711.9), p = 0.016), but there was no difference in total VEGF levels. BAL cells expressed mRNA for sVEGFR-1 and produced sVEGFR-1 protein which increased following incubation with tumour necrosis factor alpha. CONCLUSION: This study shows for the first time the presence of sVEGFR-1 in the BAL fluid of patients with ARDS. This may explain the presence of reduced bioactive VEGF in patients early in the course of ARDS.

Adolescent↗
PubMed2005

Funisitis associated with leptospiral abortion in an equine placenta.

Funisitis, inflammation of the umbilical cord, is well recognized in human placentas. This report describes a case of funisitis associated with leptospiral infection in the placenta of a Thoroughbred foal born prematurely. The umbilical cord had diffuse superficial yellow discoloration along its entire length. Microscopic evaluation showed an exudate of neutrophils admixed with fibrin on the surface. Warthin-Starry staining showed spirochetes in the Wharton's jelly of the umbilical cord. A locally extensive, severe placentitis not involving the star and allantoic cystic hyperplasia were the other lesions observed in the allantochorion. Leptospira funisitis is similar to the funisitis of congenital syphilis in humans, although there are some major microscopic differences. In Leptospira funisitis, lesions were limited to the cord surface, whereas in lesions in human umbilical cords with Treponema pallidum infection, the changes are observed mostly around the vessels and in the Wharton's jelly.

Abortion, Veterinary↗
PubMed2004

Effects of random and systematic perturbations in a one-dimensional photonic crystal wavelength converter.

We study the problem of the tolerance to fabrication errors in one-dimensional photonic crystal wavelength converters. In particular we consider the case of wavelength conversion obtained via quasiphase matching (QPM) based on a periodic amplitude modulation of the fundamental wave (Bloch-mode-QPM). Both numerical simulations of a waveguide-based structure and experimental results in an AlGaAs thin-film multilayer show that the proposed QPM mechanism is extremely tolerant to both systematic and random errors in the periodicity and duty cycle of the grating.

Journal Article↗
PubMed2004

BK viral infection in an Australian pediatric renal transplant population.

BK virus (BKV) is recognized as a significant cause of renal allograft dysfunction in adults, and there is growing awareness of its importance in the pediatric population. Eighteen pediatric renal transplant recipients and 18 age-matched controls were prospectively studied. Anti-BKV immunoglobulin G (IgG) and IgM titres were assayed in all subjects at entry to the study. Polymerase chain reaction (PCR) for BKV DNA was performed on urine and serum at entry, and prospectively tested again at 4, 8 and 12 months. Mean age +/- s.d. of transplant recipients and controls was 14.6 +/- 3.3 and 13.9 +/- 0.33 yr respectively [not significant (NS)]. Transplant patients were studied at a mean time of 5.6 +/- 4.2 yr post-transplant. 56% of transplant patients and 39% of controls were seropositive (+ve BKV IgG) (NS). Plasma BKV PCR was positive in one transplant patient (who also had positive urine PCR) and in none of the controls. The prevalence of positive urine PCR in transplant patients was greater than in controls (33% vs. 0%, p = 0.02). Positive urine BKV PCR was more commonly found in patients treated with mycophenolate than azathioprine (p = 0.04). We conclude that the prevalence of BKV seropositivity and viral activation in this Australian pediatric renal transplant population is similar to that reported in adult and pediatric populations in other countries. BK viruria was more common in children with greater immunosuppression, suggesting that this group is at higher risk of BKV induced nephropathy.

Adolescent↗
PubMed2004

Virtual outreach: a randomised controlled trial and economic evaluation of joint teleconferenced medical consultations.

OBJECTIVES: To test the hypotheses that virtual outreach would reduce offers of hospital follow-up appointments and reduce numbers of medical interventions and investigations, reduce numbers of contacts with the health care system, have a positive impact on patient satisfaction and enablement, and lead to improvements in patient health status. To perform an economic evaluation of virtual outreach. DESIGN: A randomised controlled trial comparing joint teleconsultations between GPs, specialists and patients with standard outpatient referral. It was accompanied by an economic evaluation. SETTING: The trial was centred on the Royal Free Hampstead NHS Trust, London, and the Royal Shrewsbury Hospital Trust in Shropshire. The project teams recruited and trained a total of 134 GPs from 29 practices and 20 consultant specialists. PARTICIPANTS: In total, 3170 patients were referred, of whom 2094 consented to participate in the study and were eligible for inclusion. In all, 1051 patients were randomised to the virtual outreach group and 1043 to standard outpatient appointments. The patients were followed 6 months after their index consultation. INTERVENTIONS: Patients randomised to virtual outreach underwent a joint teleconsultation, in which they attended the general practice surgery where they and their GP consulted with a hospital specialist via a videolink between the hospital and the practice. MAIN OUTCOME MEASURES: Outcome measures included offers of follow-up outpatient appointments, numbers of tests, investigations, procedures, treatments and contacts with primary and secondary care, patient satisfaction (Ware Specific Visit Questionnaire), enablement (Patient Enablement Instrument) and quality of life (Short Form-12 and Child Health Questionnaire). An economic evaluation of the costs and consequences of the intervention was undertaken. Sensitivity analysis was used to test the robustness of the results. RESULTS: Patients in the virtual outreach group were more likely to be offered a follow-up appointment. Significant differences in effects were observed between the two sites and across different specialities. Virtual outreach increased the offers of follow-up appointments more in Shrewsbury than in London, and more in ENT and orthopaedics than in the other specialities. Fewer tests and investigations were ordered in the virtual outreach group, by an average of 0.79 per patient. In the 6-month period following the index consultation, there were no significant differences overall in number of contacts with general practice, outpatient visits, accident and emergency contacts, inpatient stays, day surgery and inpatient procedures or prescriptions between the randomised groups. Tests of interaction indicated that virtual outreach decreased the number of tests and investigations, particularly in patients referred to gastroenterology, and increased the number of outpatient visits, particularly in those referred to orthopaedics. Patient satisfaction was greater after a virtual outreach consultation than after a standard outpatient consultation, with no heterogeneity between specialities or sites. However, patient enablement after the index consultation, and the physical and psychological scores of the Short Form-12 for adults and the scores on the Child Health Questionnaire for children under 16, did not differ between the randomised groups at 6 months' follow-up. NHS costs over 6 months were greater for the virtual outreach consultations than for conventional outpatients, pound 724 and pound 625 per patient, respectively. The index consultation accounted for this excess. Cost and time savings to patients were found. Estimated productivity losses were also less in the virtual outreach group. CONCLUSIONS: Virtual outreach consultations result in significantly higher levels of patient satisfaction than standard outpatient appointments and lead to substantial reductions in numbers of tests and investigations, but they are variably associated with increased rates of offer of follow-up according to speciality and site. Changes in costs and technological advances may improve the relative position of virtual consultations in future. The extent to which virtual outreach is implemented will probably be dependent on factors such as patient demand, costs, and the attitudes of staff working in general practice and hospital settings. Further research could involve long-term follow-up of patients in the virtual outreach trial to determine downstream outcomes and costs; further study into the effectiveness and costs of virtual outreach used for follow-up appointments, rather than first-time referrals; and whether the costs of virtual outreach could be substantially reduced without adversely affecting the quality of the consultation if nurses or other members of the primary care team were to undertake the hosting of the joint teleconsultations in place of the GP. Qualitative work into the attitudes of the patients, GPs and hospital specialists would also be valuable.

Adult↗
PubMed2002

Joint teleconsultations (virtual outreach) versus standard outpatient appointments for patients referred by their general practitioner for a specialist opinion: a randomised trial.

BACKGROUND: The current model of general practitioner referral of patients to hospital specialists in the UK is sometimes associated with unnecessary duplication of investigations and treatments. We aimed to compare joint teleconsultations between general practitioners, specialists, and patients (virtual outreach) with standard outpatient referral. METHODS: Virtual outreach services were established in London and Shrewsbury. The general practitioners referred 3170 patients, of whom 2094 consented to participate in the study and were eligible for inclusion. 1051 patients were randomly assigned virtual outreach, and 1043 standard outpatient appointments. We followed up the patients for 6 months after their index consultation. The primary outcome measure was the offer of a follow-up outpatient appointment. Analysis was by intention to treat. FINDINGS: More patients in the virtual outreach group than the standard group were offered a follow-up appointment (502 [52%] vs 400 [41%], odds ratio 1.52 [95% CI 1.27-1.82], p<0.0001). Significant differences in effects were observed between the two sites (p=0.009) and across different specialties (p<0.0001). Virtual outreach increased the offers of follow-up appointments more in Shrewsbury than in London, and more in ear, nose, and throat surgery and orthopaedics than in the other specialties. Fewer tests and investigations were ordered in the virtual outreach group by an average of 0.79 per patient (0.37-1.21, p=0.0002). Patients' satisfaction (analysed per protocol) was greater after a virtual outreach consultation than after a standard outpatient consultation (mean difference 0.33 scale points [95% CI 0.23-0.43], p<0.0001), with no heterogeneity between specialties or sites. INTERPRETATION: The trial showed that allocation of patients to virtual outreach consultations is variably associated with increased offers of follow-up appointments according to site and specialty, but leads to significant increases in patients' satisfaction and substantial reductions in tests and investigations. Efficient operation of such services will require appropriate selection of patients, significant service reorganisation, and provision of logistical support.

Ambulatory Care Facilities↗