Development of a novel immunoassay for the iron regulatory peptide hepcidin.

To date there have been few published immunoassays for the important iron regulator hepcidin. This study describes a novel competitive radioimmunoassay (RIA) for the bioactive hepcidin peptide. A rabbit anti-hepcidin polyclonal antibody was produced using synthetic hepcidin radiolabelled with 125I to produce a competitive RIA. Normal patient (n=47) samples were collected and assayed for hepcidin to determine a reference range. Other patient groups collected were ulcerative colitis (UC; n=40), iron deficiency anaemia (IDA; n=15), chronic kidney disease not requiring dialysis (CKD; n=45) and chronic kidney disease requiring dialysis (HCKD; n=94). Detection limit of the assay was determined as 0.6 ng/mL. Intra-assay precision was 5 ng/mL (7.2%) and 50 ng/mL (5.8%), interassay precision was 5 ng/mL (7.6%) and 50 ng/mL (6.7%). Analytical recovery was 98% (5 ng/mL), 94% (10 ng/mL) and 97% (50 ng/mL). The assay was linear up to 200 ng/mL. No demonstrable cross-reactivity with human insulin, glucagon I, angiotensinogen I, beta-defensin 1-4, alpha-defensin-1 and plectasin was observed. There was significant correlation (r=0.96, P < or = 0.0001) between the hepcidin RIA and an established hepcidin SELDI-TOF-MS method. Analysis of the normal human samples gave a reference range of 1.1-55 ng/mL for hepcidin. Further statistical evaluation revealed a significant difference between male and female hepcidin levels. There was significant correlation between hepcidin and ferritin in the control group (r=0.6, P < or = 0.0001). There was also a significant difference between the normal and disease groups (P < or = 0.0001). Healthy volunteers (n=10) showed a diurnal increase in plasma hepcidin at 4.00 pm compared to 8.00 am. A robust and optimised immunoassay for bioactive hepcidin has been produced and the patient sample results obtained further validates the important role of hepcidin in iron regulation, and will allow further investigation of this important peptide and its role in iron homeostasis.

Topical or oral ibuprofen for chronic knee pain in older people. The TOIB study.

OBJECTIVES: To determine whether GPs should advise their older patients with chronic knee pain to use topical or oral non-steroidal anti-inflammatory drugs (NSAIDs). DESIGN: An equivalence study was designed to compare the effect of advice to use preferentially oral or topical ibuprofen (an NSAID) on knee pain and disability, NSAID-related adverse effects and NHS/societal costs, using a randomised controlled trial (RCT) and a patient preference study (PPS). Reasons for patient preferences for topical or oral preparations, and attitudes to adverse effects, were explored in a qualitative study. SETTING: Twenty-six general practices in the UK. PARTICIPANTS: Participants comprised 585 people with knee pain, aged 50 years or over; 44% were male, mean age 64 years. The RCT had 282 participants: 144 in the oral group and 138 in the topical group. The PPS had 303 participants: 79 in the oral group and 224 in the topical group. INTERVENTIONS: Advice to use preferentially oral or topical NSAIDs for knee pain. OUTCOME MEASURES: The primary outcome measure was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Secondary outcome measures were the Short Form with 36 Items (SF-36), perceived troublesomeness of knee pain, satisfaction with health status, major adverse effects (unplanned hospital admissions and deaths) and minor adverse events over 12 months. The health economic analysis measured the comparative cost per quality-adjusted life-year (QALY) from both an NHS and a societal perspective over 1 and 2 years. RESULTS: Changes in the global WOMAC score at 12-months were equivalent in both studies: topical - oral, RCT difference=2 [95% confidence interval (CI) -2 to 6], PPS difference=1 (95% CI -4 to 6). There were no differences in the secondary outcomes, except for a suggestion, in the RCT, that those in the topical group were more likely to have more severe overall pain and disability as measured by the chronic pain grade, and more likely to report changing treatment because of inadequate pain relief. There were no differences in the rate of major adverse effects but some differences in the number of minor ones. In the RCT, 17% and 10% in the oral and the topical group, respectively, had a defined respiratory adverse effect (95% CI of difference -17% to -2.0%); after 12 months, the change in serum creatinine was 3.7 mmol/l (95% CI 0.9 to 6.5) less favourable in the oral than in the topical group, and 11% of those in the oral group reported changing treatment because of adverse effects compared with 1% in the topical group (p=0.02). None of these differences were seen in the PPS. Oral NSAIDs cost the NHS 191 pounds and 72 pounds more per participant over 1 year in the RCT and PPS respectively. In the RCT the cost per QALY in the oral group, from an NHS perspective, was in the range 9000-12,000 pounds. In the PPS it was 2564 pounds over 1 year, but over 2 years the oral route was more cost-effective. Patient preference for medication type was affected by previous experience of medication (including adverse reactions), other illness, pain elsewhere, anecdotes, convenience, severity of pain and perceived degree of degeneration. Lack of understanding about knee pain and the action of medication led to increased tolerance of symptoms. Potentially important symptoms may inadvertently have been disregarded, increasing participants' risk of suffering a major adverse effect. CONCLUSIONS: Advice to use either oral or topical preparations has an equivalent effect on knee pain, but oral NSAIDs appear to produce more minor adverse effects than topical NSAIDs. Generally, these results support advising older people with knee pain to use topical rather than oral NSAIDS. However, for patients who prefer oral NSAID preparations rather than a topical NSAID, particularly those with more widespread or severe pain, the oral route is a reasonable treatment option, provided that patients are aware of the risks of potentially serious adverse effects from oral medication. Further research is needed into strategies to change prescribing behaviour and ensure that older patients are aware of the potential risks and benefits of using NSAIDs. Observational studies are needed to estimate rates of different predefined minor adverse effects associated with the use of oral NSAIDs in older people as are long-term studies of topical NSAIDs in those for whom oral NSAIDs are not appropriate.

Chronic forearm pain presents as a transient and indistinct pain site in a community setting: results from a UK population survey.

OBJECTIVES: To investigate the prevalence of chronic forearm pain in a non-occupational community setting over a 2-year period. METHOD: A longitudinal community-based postal questionnaire survey conducted in the south-eastern quadrant of England. RESULTS: We received 2493/4172 (60%) responses at baseline and we followed up 429 of these 2 years later: 252 responded (59%). Forearm pain prevalence was 4% at baseline and 5% at follow-up. Over 95% of those with forearm pain had pain in other areas [odds ratio 1.5 (95% confidence interval 1.3-1.7)] and it was most commonly associated with elbow and wrist pain. Seventy-six per cent of those with forearm pain at baseline recovered. At follow-up, 78% of those with chronic forearm pain had new-onset forearm pain. CONCLUSIONS: Persistent forearm pain (pain for over 2 years) was rare and the capacity for recovery was good (76%). Isolated forearm pain as a diagnostic category is of little utility. Treating and managing forearm pain in a site-specific manner is unlikely to be successful owing to its strong association with pain in other areas. In the community, forearm pain laterality was not evident; our findings suggest that forearm pain in the workplace is influenced by different factors to those in a community setting.

Recent progress in PYY research--an update report for 8th NPY meeting.

UNLABELLED: PYY(3-36) is a gut regulatory peptide which has recently been found to reduce appetite. Variability of this effect across different experimental conditions has led to confusion and polarization of opinion on its potential as an anti-obesity treatment. This review summarizes recent progress in this area. The basic anorexigenic effect leading to weight loss in rodents has now been confirmed by several groups. Anorexia has also been confirmed in human studies although optimal route and dosing remain to be defined. Gastric bypass causes PYY levels to rise, which may in part mediate the weight loss occurring after this surgery, and levels have been found to be normal or low in obese people. The straightforward ARC model of mechanism, involving inhibition and activation, respectively, of NPY and POMC neurons, is giving way to a more complicated system involving vagal afferent signals. CONCLUSION: It works, but not how we thought it did.

Real-time gait analysis with accelerometer-based smart shoes.

In this paper, we present the evaluation of a new smart shoe capable of performing gait analysis in real time. The system is exclusively based on accelerometers which minimizes the power consumption. The estimated parameters are activity class (rest/walk/run), step cadence, ground contact time, foot impact (zone, strength, and balance), forward distance, and speed. The different parameters have been validated with a customized database of 26 subjects on a treadmill and video data labeled manually. Key measures for running analysis such as the cadence is retrieved with a maximum error of 2%, and the ground contact time with an average error of 3.25%. The classification of the foot impact zone achieves a precision between 72% and 91% depending of the running style. The presented algorithm has been licensed to ICON Health & Fitness Inc. for their line of wearables under the brand iFit.

Real-time monitoring of swimming performance.

This article presents the performance results of a novel algorithm for swimming analysis in real-time within a low-power wrist-worn device. The estimated parameters are: lap count, stroke count, time in lap, total swimming time, pace/speed per lap, total swam distance, and swimming efficiency (SWOLF). In addition, several swimming styles are automatically detected. Results were obtained using a database composed of 13 different swimmers spanning 646 laps and 858.78 min of total swam time. The final precision achieved in lap detection ranges between 99.7% and 100%, and the classification of the different swimming styles reached a sensitivity and specificity above 98%. We demonstrate that a swimmers performance can be fully analyzed with the smart bracelet containing the novel algorithm. The presented algorithm has been licensed to ICON Health & Fitness Inc. for their line of wearables under the brand iFit.

Dynamic correlation of apoptosis and immune activation during treatment of HIV infection.

T cells from HIV infected patients undergo spontaneous apoptosis at a faster rate than those from uninfected patients, are abnormally susceptible to activation induced cell death (AICD), and undergo increased apoptosis in response to Fas receptor ligation. These observations have led to the hypothesis CD4 T cell apoptosis may be a mechanism of CD4 T cell depletion and the pathogenesis of AIDS. Successful treatment of HIV infected patients is accompanied by quantitative and qualitative improvements in immune function reflecting at least partial reversibility of the underlying pathogenesis of HIV. In this report we correlate improvements in markers of immune function with a decrease in apoptosis, and changes in its regulation. Therapy with nelfinavir plus saquinavir in combination with two nucleoside analogue inhibitors of reverse transcriptase dramatically reduces plasma viremia and increases CD4 T cell counts. Coincident with these improvements, CD38 and HLA-DR coexpression on both CD4 and CD8 T cells decrease, and CD45RA and CD62L coexpression increase. Furthermore, spontaneous apoptosis decreases in both CD4 and CD8 T cells (CD4 apoptosis 17.4 vs 2.6%, P=0.005; CD8 apoptosis 15.0 vs 1.0%, P<0.001), as does both Fas mediated apoptosis (CD4 apoptosis 19.0 vs 3.5%, P=0.03; CD8 apoptosis 13.7 vs 1.5%, P=0.002) and CD3 induced AICD (CD4 apoptosis 13.7 vs 3.2%, P=0.001; CD8 apoptosis 29 vs 2.2%, P=0.08). Changes in apoptosis are not associated with changes in Fas receptor expression, but are significantly correlated with changes in activation marker profiles. Although this suggests a possible regulatory role for the apoptosis inhibitory protein FLIP, direct assessment did not reveal quantitative differences in FLIP expression between apoptosis resistant PBL's from HIV negative patients, and apoptosis sensitive PBL's from HIV positive patients. These findings support the hypothesis that apoptosis mediates HIV induced CD4 T cell depletion, but indicate the need for further studies into the molecular regulation of HIV induced apoptosis.

Structured Frameworks to Increase the Transparency of the Assessment of Benefits and Risks of Medicines: Current Status and Possible Future Directions.

Structured frameworks for benefit-risk analysis in drug licensing decisions are being implemented across a number of regulatory agencies worldwide. The aim of these frameworks is to aid the analysis and communication of the benefit-risk assessment throughout the development, evaluation, and supervision of medicines. In this review, authors from regulatory agencies, pharmaceutical companies, and academia share their views on the different frameworks and discuss future directions.

Lack of effect of serum amyloid A (SAA) on the ability of high-density lipoproteins to inhibit endothelial cell adhesion molecule expression.

Studies have been conducted to determine whether the ability of high density lipoproteins (HDL) to inhibit the cytokine-induced expression of vascular cell adhesion molecule-1 (VCAM-1) in endothelial cells is altered by the presence in HDL of the acute phase reactant, serum amyloid-A (SAA). Preparations of HDL(3) were isolated on two separate occasions from the plasma of each of 19 patients: the first was collected before and the second 3 days after undergoing coronary artery bypass graft surgery. Whereas the preoperative HDL(3) sample contained no SAA, in the postoperative sample SAA accounted for an average of 42% of the HDL(3) protein. The preoperative HDL(3) and postoperative, SAA-enriched HDL(3) were identical in terms of their ability to inhibit the tumour necrosis factor-alpha (TNF-alpha)-induced expression of VCAM-1 in human umbilical vein endothelial cells (HUVECs). To assess the effect of having an even greater SAA enrichment of HDL(3), samples of HDL(3) were incubated with purified SAA, which displaced almost all of the apoAI and about 40% of the apoAII from the HDL(3). This in vitro SAA-enriched HDL(3) inhibited the TNF-alpha-induced expression of VCAM-1 in HUVECs in a concentration dependent manner, which was identical to that of the unmodified HDL(3). The presence of SAA did not alter the cell-surface binding of HDL(3) to endothelial cells. It has been concluded that the presence of SAA in HDL has no effect on the ability of these lipoproteins either to inhibit the expression of VCAM-1 in endothelial cells or to bind to proteins on the endothelial cell surface.

Blood pressure and hypertension in middle-aged British men.

Blood pressure measurements in 7735 middle-aged men from general practices in 24 towns in England, Wales and Scotland provide information on the prevalence of hypertension and its management in Great Britain. Despite a substantial correlation (r = 0.70) between systolic and diastolic blood pressures, individuals can show considerable discrepancies between these two measurements; they are not interchangeable. This observation has important implications for the choice of criteria used to define hypertension. However defined, the prevalence of hypertension increases markedly with age, increasing body mass index and with heavy alcohol consumption. It is not related to smoking and only to a small extent to social class. Diastolic hypertension (greater than or equal to 90 mmHg) was present in 26% and systolic hypertension (greater than or equal to 160 mmHg) in 22% of these men. In both systolic and diastolic hypertension, only one quarter of affected men could recall having been diagnosed as hypertensive by a doctor, and only one third of these were on regular antihypertensive treatment. There is a threefold variation in the prevalence of measured hypertension in the 24 towns with a trend towards higher rates in Northern England and Scotland. No relationship was seen between the prevalence rates of measured hypertension in the towns and the rates of doctor diagnosis of hypertension. Cardiovascular mortality rates in the towns were correlated with the measured prevalence rates for systolic and diastolic hypertension (r = 0.70 and r = 0.57, respectively). The geographic variations in blood pressure and hypertension in Great Britain provide a major opportunity for research into the causes of 'essential' hypertension.

Comparison of Ga-67 citrate images obtained with rectilinear scanner and large-field Anger camera.

Two methods for Ga-67 citrate imaging were compared on 20 patients. Scans were performed using approximately equal procedure time with two instruments: (A) a dual 5-in. rectilinear scanner with medium-energy collimator, with a single window spanning both the 93-keV and the 185-keV spectral peaks; and (B) a large-field (15-in. diam) Anger camera equipped with moving table, medium-energy collimator, and three windows covering the 93-keV, 185-keV, and 300-keV peaks separately. Sixteen abnormal sites and 24 normal sites were selected for comparison. Each site was evaluated by four physicians experienced in interpreting Ga-67 citrate images. The observers performed significantly better using the images obtained with the large-field camera (three windows) than with the dual 5-in. scanner (single window).

Prognostic significance of transient myocardial ischemia on ambulatory monitoring after acute myocardial infarction.

The prognostic value of ambulatory ST-segment monitoring after myocardial infarction was prospectively assessed in 203 patients both early (mean 6 days, n = 201) and late (38 days, n = 177). During at least 1 year of follow-up there were 21 cardiac deaths and 44 cardiac events (death, reinfarction or coronary revascularization). ST depression was seen less often during early than late monitoring (29 of 201 [14%] vs 56 of 177 [32%]). Early ST depression was significantly associated with increased mortality (7 of 29 [24%] vs 14 of 172 [8%]) (< 0.05) and increased cardiac events (13 of 29 [45%] vs 30 of 172 [17%]) (p < 0.001) and had independent value after allowing for clinical factors and coronary prognostic indexes (adjusted relative risks 3.40 and 2.70, respectively). ST depression on late monitoring was only associated with increased cardiac events when it was: (1) frequent (e.g., > or = 3 episodes/day [10 of 31 patients, 32% vs 18 of 146, 12%]) (p < 0.01); (2) prolonged (e.g., > or = 20 minutes/day [8 of 25, 32% vs 20 of 152, 13%]) (p < 0.05); or (3) severe (e.g., maximum of > or = 1.5 mm [8 of 28, 29% vs 20 of 149, 13%]) (p < 0.05). Thus, ST depression occurs less frequently during ambulatory monitoring before discharge than during late monitoring, but is a more specific prognostic indicator; however, it is more benign during late monitoring. Ambulatory ST-segment monitoring can be used to predict prognosis in the first year after myocardial infarction, although its relative value as a screening test compared with exercise testing remains to be established.

The relationship between blood lead, blood pressure, stroke, and heart attacks in middle-aged British men.

The relationship between blood lead concentration and blood pressure is examined in a survey of 7371 men aged 40 to 59 from 24 British towns. After allowance for relevant confounding variables, including town of residence and alcohol consumption, there exists a very weak but statistically significant positive association between blood lead and both systolic and diastolic blood pressure. These cross-sectional data indicate that an estimated mean increase of 1.45 mm Hg in systolic blood pressure occurs for every doubling of blood lead concentration with a 95% confidence interval of 0.47 to 2.43 mm Hg. After 6 years of follow-up, 316 of these men had major ischemic heart disease, and 66 had a stroke. After allowance for the confounding effects of cigarette smoking and town of residence there is no evidence that blood lead is a risk factor for these cardiovascular events. However, as the blood lead-blood pressure association is so weak, it is unlikely that any consequent association between lead and cardiovascular disease could be demonstrated from prospective epidemiological studies. An overview of data from this and other large epidemiological surveys provides reasonably consistent evidence on lead and blood pressure. While NHANES II data on 2254 U.S. men indicate a slightly stronger association between blood lead and systolic blood pressure, data from two Welsh studies on over 2000 men did not show a statistically significant association. However, the overlapping confidence limits for all these studies suggest that there may be a weak positive statistical association whereby systolic blood pressure is increased by about 1 mm Hg for every doubling of blood lead concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Radiocontrast-induced acute renal failure: allocations and outcomes.

Radiocontrast-induced nephropathy causes significant morbidity and mortality with increase in hospital length of stay and costs. It can be largely prevented by identifying the patients at risk before the procedure. Once the at-risk patient is identified, ways to prevent the development of acute renal failure are: avoiding volume depletion, aggressive saline hydration with the aim of keeping the urine output over 150 mL/hour, and the use of low-osmolality contrast agents, with as little volume used as possible. There is theoretical potential for the dopamine DA1 agonist fenoldopam as a preventive agent, and this is currently being tested in randomized trials.

The demographic characteristics of pregnant women infected with cytomegalovirus.

An analysis was made of the demographic characteristics of 1000 women who were screened for serological evidence of cytomegalovirus (CMV) infection while receiving antenatal care in central London. The prevalence of antibodies against CMV was shown, by multiple discriminant analysis, to be significantly associated with non-Caucasian race (p less than 0.001), increasing maternal age (p less than 0.001) and poor social class (p less than 0.05). These results are interpreted as reflecting increased childhood exposure to CMV as a result of poor social environments. When data from 48 women who acquired primary CMV during pregnancy were analysed, infection was also related to non-Caucasian race (p less than 0.01), but in contrast, there was no demonstrable effect of social class, maternal age or marital status. We conclude that pregnant women acquiring the form of CMV infection with the greatest pathological potential for the fetus (primary infection) belong primarily to the middle-class sections of communities. Since middle-class women traditionally avail themselves of prophylactic measures, this result provides some optimism for the ultimate control of this common disease by immunization.

Lead exposure and children's intellectual performance.

The Institute of Child Health/Southampton study is the largest cross-sectional survey of lead exposure and children's intelligence. 402 six year olds in London with tooth lead concentration in three pre-defined ranges were selected for neuropsychological testing. This paper presents new findings on the relationship between child IQ and tooth lead levels which build on previous findings in four respects: Rather than simply classifying children into high, medium and low lead groups the actual concentrations of lead in each child's tooth have been used to provide a more powerful assessment of the association between IQ and body lead burden. The influence of parental and social factors on child IQ is explored in detail in order to see if any residual lead-IQ association exists after allowance for such confounders. The methods of multiple regression, including an 'optimal' statistical policy, are more fully described. The possibility of interactions between lead and confounders is explored. Findings are that parental IQ is the most important influence on child IQ, though several other factors (eg: family size, social class and quality of marital relationships) were also significantly related. There was no overall evidence that tooth lead concentrations were related to child IQ once these other factors were taken into account. However, a significant interaction between tooth lead and sex of child indicates that the lead-IQ association appears much more pronounced in boys. This unexpected finding needs cautious interpretation and further exploration in other studies.

Diurnal variations in serum biochemical and haematological measurements.

Twenty five biochemical and haematological measurements were determined on nonfasting blood and serum samples collected between 9 am and 7 pm from a representative group of 7685 British middle-aged men. Most measurements showed significant diurnal variations, but only for bilirubin, phosphate, and triglyceride did time of day account for more than 5% of the between subject variance. Serum bilirubin concentrations showed a pronounced downward trend in the afternoon, the mean value after 6 pm being 30% lower than the mean value in the morning. Mean serum triglyceride and phosphate concentrations increased steadily through the day. Mean concentrations of potassium, haemoglobin, and haematocrit and red cell count were higher in the morning, while urea and creatinine concentrations and white cell count had higher means in the afternoon. Glucose showed a pattern consistent with short term response to meals. The effects of these diurnal trends on routine use of biochemical tests needs careful consideration, and a greater understanding of their biological mechanisms is required.

Randomized controlled trials in cystic fibrosis (1966-1997) categorized by time, design, and intervention.

The improved prognosis of cystic fibrosis (CF) over the last three decades has been associated with an increased use of a range of treatments, but it is important that the use of an individual treatment is based on evidence. Well-designed randomized controlled trials (RCTs) are a robust method for evaluating the effectiveness of such treatments. We have developed a register of RCTs in CF and have studied when they were performed, their design, and what interventions were investigated. We identified 506 RCTs; 37.5% were identified solely as abstract reports in conference proceedings. There has been about a 30-fold increase in the number of RCTs in CF since 1966. A high proportion of the RCTs (72.7%) had a sample size of 30 or less, and only 8.7% were multicenter trials. Reporting of study design was poor: in 51.4% the report did not state whether there was any blinding in the trial design; 53.6% of studies were of crossover design. The most common interventions studied were antibiotic treatments and physiotherapy, but a number of commonly used therapies had been evaluated only in a small number of patients. Although the number of RCTs of interventions in CF patients has increased over the last 25 years, the sample sizes of these trials are generally too small to indicate whether the intervention was effective, and very few were multicenter. Future RCTs in CF are more likely to provide clinically useful answers if higher numbers of patients are recruited into large, well-designed multicenter trials. This should be a priority of the organization of future research in CF.

Time to publication as full reports of abstracts of randomized controlled trials in cystic fibrosis.

OBJECTIVES: To determine 1) what proportion of abstracts of randomized controlled trials (RCTs) presented at international conferences on cystic fibrosis (CF) are published as full reports, 2) time to publication, and 3) factors that might delay or prevent publication. METHODS: At the end of 1995, the Cochrane CF Group's register of RCTs contained 199 abstracts describing 180 RCTs. Abstracts were identified by handsearching 44 abstract books of three international CF conferences over a 30-year period. We searched the register for subsequent full reports of these RCTs and used survival analysis to investigate time to publication. Using the log-rank test, we examined 1) whether there is a difference in time to publication between reports where the investigators concluded that the test treatment was as effective as or better than the control treatment, and reports where it was not, and 2) whether there is a difference in time to publication according to sample size. RESULTS: Thirty-two percent of the 178 abstracts analyzed were subsequently published in full. Survival analysis indicated that the proportions published before 12 months, 2 years, and 5 years were 8.1%, 29%, and 40% respectively. No difference in time to publication was identified when the abstracts were stratified according to conclusions or sample size; no significant association (P > 0.05) existed between time to publication and both sample size and conclusions together. CONCLUSION: Only a small proportion of abstracts of RCTs presented at international conferences on CF are followed by full publication, and usually only after several years. Therefore, many potentially valuable studies do not reach a wide audience. However, we found no consistent factors which might delay or prevent publication.