Surveillance of female patients with inherited bleeding disorders in United States Haemophilia Treatment Centres.

Inherited bleeding disorders are especially problematic for affected girls and women due to the monthly occurrence of menstrual periods and the effects on reproductive health. Although heavy menstrual bleeding (HMB) is the most common manifestation, females with inherited bleeding disorders (FBD) experience other bleeding symptoms throughout the lifespan that can lead to increased morbidity and impairment of daily activities. The purpose of this article is to describe the utility of a female-focused surveillance effort [female Universal Data Collection (UDC) project] in the United States Haemophilia Treatment Centres (HTCs) and to describe the baseline frequency and spectrum of diagnoses and outcomes. All FBD aged 2 years and older receiving care at selected HTCs were eligible for enrollment. Demographic data, diagnoses and historical data regarding bleeding symptoms, treatments, gynaecological abnormalities and obstetrical outcomes were analysed. Analyses represent data collected from 2009 to 2010. The most frequent diagnoses were type 1 von Willebrand's disease (VWD) (195/319; 61.1%), VWD type unknown (49/319; 15.4%) and factor VIII deficiency (40/319; 12.5%). HMB was the most common bleeding symptom (198/253; 78.3%); however, 157 (49.2%) participants reported greater than four symptoms. Oral contraceptives were used most frequently to treat HMB (90/165; 54.5%), followed by desmopressin [1-8 deamino-D-arginine vasopressin (DDAVP)] (56/165; 33.9%). Various pregnancy and childbirth complications were reported, including bleeding during miscarriage (33/43; 76.7%) and postpartum haemorrhage (PPH) (41/109; 37.6%). FBD experience multiple bleeding symptoms and obstetrical-gynaecological morbidity. The female UDC is the first prospective, longitudinal surveillance in the US focusing on FBD and has the potential to further identify complications and reduce adverse outcomes in this population.

Waist-to-height ratios in relation to BMI z-scores in three ethnic groups from a representative sample of New Zealand children aged 5-14 years.

Waist-to-height ratio (WHtR) is purported to offer a simpler index of health risk than body mass index (BMI) in children as it requires no adjustment for age or sex. Little is known regarding the usefulness of WHtR in different ethnic groups. The aim of this study was to compare the WHtR cutpoints associated with BMI definitions of overweight and obesity in a nationally representative sample of New Zealand children. Height, weight and waist circumference were measured in 3006 children (51.5% male) aged 5-14 years (n=1107 Maori, n=985 Pacific and n=924 New Zealand European and Others (NZEO)). A WHtR >0.5 was more common in Pacific (43.4%) and Maori (33.1%) children than in NZEO children (20.8%, P<0.001), with 25.6% of children overall being above this cutoff. Although ethnicity influenced the relationship between BMI and WHtR (P<0.01), differences were clinically insignificant as illustrated by the similarity in WHtR values for a given BMI (WHtR of 0.47 in Maori, 0.46 in Pacific and 0.48 in European boys at the 85th BMI percentile). The present results suggest that having WHtR values >0.5 should be equally useful in evaluating cardiovascular health risks in groups of Maori, Pacific and NZEO children.

Osteoporosis and gait and balance disturbances in older sarcopenic obese New Zealanders.

UNLABELLED: Bone, muscle, and fat may affect gait and balance in older adults. Osteoporosis was prevalent in low muscle mass participants and related to gait and balance deficits. Low muscle combined with high fat mass had more functional deficits and poorer bone health, which has implications for falls risk and fractures. INTRODUCTION: Decreasing bone density and muscle mass and increasing fat mass may act synergistically to affect gait and balance in older adults. METHODS: One hundred eighty-three older adults (age 72.7 +/- 6 years, range 56-93; body mass index 28.2 +/- 4.9, range 16.6-46.0) were recruited from a New Zealand falls prevention intervention trial. Total and appendicular skeletal muscle mass (ASM), percent fat, and bone mineralization were assessed by dual energy X-ray absorptiometry and used to characterize normal lean (NL, n = 51), sarcopenic (SS, n = 18), sarcopenic obese (SO, n = 29), and obese (OO, n = 85) phenotypes. Functional performance was assessed using timed up and go, chair stand, single leg stand, and step test. Regression models were adjusted for age, sex, medications, and physical activity. RESULTS: Femoral neck osteoporosis was present in 22% SS, 17% SO, 12% NL, and 7% OO. Femoral neck osteoporosis with low ASM predicted poor chair stand performance (beta -3.3, standard error 1.6, p = 0.04). SO scored lowest on the chair stand (p = 0.03) and step test (p = 0.03). Higher ASM predicted faster timed up and go performance (p = 0.001). CONCLUSIONS: Osteoporosis was prevalent in low ASM groups (SS and SO) and related to gait and balance deficits, particularly in the SO. This has implications for falls risk, fractures, and interventions.

Early life stage salinity tolerance of wild and hatchery-reared juvenile pink salmon Oncorhynchus gorbuscha.

Salinity tolerance in wild (Glendale) and hatchery (Quinsam) pink salmon Oncorhynchus gorbuscha (average mass 0·2 g) was assessed by measuring whole body [Na(+)] and [Cl⁻] after 24 or 72 h exposures to fresh water (FW) and 33, 66 or 100% sea water (SW). Gill Na(+), K(+)-ATPase activity was measured following exposure to FW and 100% SW and increased significantly in both populations after a 24 h exposure to 100% SW. Whole body [Na(+)] and whole body [Cl⁻] increased significantly in both populations after 24 h in 33, 66 and 100% SW, where whole body [Cl⁻] differed significantly between Quinsam and Glendale populations. Extending the seawater exposure to 72 h resulted in no further increases in whole body [Na(+)] and whole body [Cl⁻] at any salinity, but there was more variability among the responses of the two populations. Per cent whole body water (c. 81%) was maintained in all groups of fish regardless of salinity exposure or population, indicating that the increase in whole body ion levels may have been related to maintaining water balance as no mortality was observed in this study. Thus, both wild and hatchery juvenile O. gorbuscha tolerated abrupt salinity changes, which triggered an increase in gill Na(+), K(+)-ATPase within 24 h. These results are discussed in terms of the preparedness of emerging O. gorbuscha for the marine phase of their life cycle.

Plasma membrane translocation of fluorescent-labeled phosphatidylethanolamine is controlled by transcription regulators, PDR1 and PDR3.

The transcription regulators, PDR1 and PDR3, have been shown to activate the transcription of numerous genes involved in a wide range of functions, including resistance to physical and chemical stress, membrane transport, and organelle function in Saccharomyces cerevisiae. We report here that PDR1 and PDR3 also regulate the transcription of one or more undetermined genes that translocate endogenous and fluorescent-labeled (M-C6-NBD-PE) phosphatidylethanolamine across the plasma membrane. A combination of fluorescence microscopy, fluorometry, and quantitative analysis demonstrated that M-C6-NBD-PE can be translocated both inward and outward across the plasma membrane of yeast cells. Mutants, defective in the accumulation of M-C6-NBD-PE, were isolated by selectively photokilling normal cells that accumulated the fluorescent phospholipid. This led to the isolation of numerous trafficking in phosphatidylethanolamine (tpe) mutants that were defective in intracellular accumulation of M-C6-NBD-PE. Complementation cloning and linkage analysis led to the identification of the dominant mutation TPE1-1 as a new allele of PDR1 and the semidominant mutation tpe2-1 as a new allele of PDR3. The amount of endogenous phosphatidylethanolamine exposed to the outer leaflet of the plasma membrane was measured by covalent labeling with the impermeant amino reagent, trinitrobenzenesulfonic acid. The amount of outer leaflet phosphatidylethanolamine in both mutant strains increased four- to fivefold relative to the parent Tpe+ strain, indicating that the net inward flux of endogenous phosphatidylethanolamine as well as M-C6-NBD-PE was decreased. Targeted deletions of PDR1 in the new allele, PDR1-11, and PDR3 in the new allele, pdr3-11, resulted in normal M-C6-NBD-PE accumulation, confirming that PDR1-11 and pdr3-11 were gain-of-function mutations in PDR1 and PDR3, respectively. Both mutant alleles resulted in resistance to the drugs cycloheximide, oligomycin, and 4-nitroquinoline N-oxide (4-NQO). However, a previously identified drug-resistant allele, pdr3-2, accumulated normal amounts of M-C6-NBD-PE, indicating allele specificity for the loss of M-C6-NBD-PE accumulation. These data demonstrated that PDR1 and PDR3 regulate the net rate of M-C6-NBD-PE translocation (flip-flop) and the steady-state distribution of endogenous phosphatidylethanolamine across the plasma membrane.

The effect of adiposity measured by dual-energy X-ray absorptiometry on lung function.

Respiratory function is impaired in obesity but there are limitations with body mass index and skin-fold thickness in assessing this effect. The present authors hypothesised that the regional distribution of body fat and lean mass, as measured by dual-energy X-ray absorptiometry (DXA), might be more informative than conventional measurements of total body fat. In total, 107 subjects (55 female, 51.4%) aged 20-50 yrs with no respiratory disease were recruited. Respiratory function tests, anthropometric measurements and a DXA scan were performed. Partial correlation and linear regression analyses were used to explore the effect of adiposity and lean body mass on respiratory function. The majority of respiratory function parameters were significantly correlated with DXA and non-DXA measurements of body fat. Neither thoracic nor abdominal fat had a greater effect. There were some differences in the effect of adiposity between the sexes. Respiratory function was negatively associated with lean body mass in females but positively associated in males. This disappeared after adjustment in females but remained in males. The effects of thoracic and abdominal body fat on respiratory function are comparable but cannot be separated from one another.

Mechanism of plasma cholesteryl ester transfer in hypertriglyceridemia.

Plasma net cholesteryl ester (CE) transfer and optimum cholesteryl ester transfer protein (CETP) activity were determined in primary hypertriglyceridemic (n = 11) and normolipidemic (n = 15) individuals. The hypertriglyceridemic group demonstrated threefold greater net CE transfer leading to enhanced accumulation of CE in VLDL. This increased net transfer was not accompanied by a change in CETP activity. In normolipidemia, but not in hypertriglyceridemia, net CE transfer correlated with VLDL triglyceride (r = 0.92, P less than 0.001). In contrast, net CE transfer in hypertriglyceridemia, but not in normolipidemia, correlated with CETP activity (r = 0.73, P less than 0.01). Correction of hypertriglyceridemia with bezafibrate reduced net CE transfer towards normal and restored the correlation with VLDL triglyceride (r = 0.90, P less than 0.005) while suppressing the correlation with CETP activity. That net CE transfer depends on VLDL concentration was confirmed by an increase of net CE transfer in normolipidemic plasma supplemented with purified VLDL. Supplementation of purified CETP to normolipidemic plasma did not stimulate net CE transfer. In contrast, net CE transfer was enhanced by addition of CETP to both plasma supplemented with VLDL and hypertriglyceridemic plasma. Thus, in normal subjects, VLDL concentration determines the rate of net CE transfer. CETP becomes rate limiting as VLDL concentration increases, i.e., in hypertriglyceridemia.

Oral vitamin D3 and calcium for secondary prevention of low-trauma fractures in elderly people (Randomised Evaluation of Calcium Or vitamin D, RECORD): a randomised placebo-controlled trial.

BACKGROUND: Elderly people who have a fracture are at high risk of another. Vitamin D and calcium supplements are often recommended for fracture prevention. We aimed to assess whether vitamin D3 and calcium, either alone or in combination, were effective in prevention of secondary fractures. METHODS: In a factorial-design trial, 5292 people aged 70 years or older (4481 [85%] of whom were women) who were mobile before developing a low-trauma fracture were randomly assigned 800 IU daily oral vitamin D3, 1000 mg calcium, oral vitamin D3 (800 IU per day) combined with calcium (1000 mg per day), or placebo. Participants who were recruited in 21 UK hospitals were followed up for between 24 months and 62 months. Analysis was by intention-to-treat and the primary outcome was new low-energy fractures. FINDINGS: 698 (13%) of 5292 participants had a new low-trauma fracture, 183 (26%) of which were of the hip. The incidence of new, low-trauma fractures did not differ significantly between participants allocated calcium and those who were not (331 [12.6%] of 2617 vs 367 [13.7%] of 2675; hazard ratio (HR) 0.94 [95% CI 0.81-1.09]); between participants allocated vitamin D3 and those who were not (353 [13.3%] of 2649 vs 345 [13.1%] of 2643; 1.02 [0.88-1.19]); or between those allocated combination treatment and those assigned placebo (165 [12.6%] of 1306 vs 179 [13.4%] of 1332; HR for interaction term 1.01 [0.75-1.36]). The groups did not differ in the incidence of all-new fractures, fractures confirmed by radiography, hip fractures, death, number of falls, or quality of life. By 24 months, 2886 (54.5%) of 5292 were still taking tablets, 451 (8.5%) had died, 58 (1.1%) had withdrawn, and 1897 (35.8%) had stopped taking tablets but were still providing data for at least the main outcomes. Compliance with tablets containing calcium was significantly lower (difference: 9.4% [95% CI 6.6-12.2]), partly because of gastrointestinal symptoms. However, potentially serious adverse events were rare and did not differ between groups. INTERPRETATION: The findings do not support routine oral supplementation with calcium and vitamin D3, either alone or in combination, for the prevention of further fractures in previously mobile elderly people.

Analog filtering methods improve leading edge timing performance of multiplexed SiPMs.

Multiplexing many SiPMs to a single readout channel is an attractive option to reduce the readout complexity of high performance time of flight (TOF) PET systems. However, the additional dark counts and shaping from each SiPM cause significant baseline fluctuations in the output waveform, degrading timing measurements using a leading edge threshold. This work proposes the use of a simple analog filtering network to reduce the baseline fluctuations in highly multiplexed SiPM readouts. With 16 SiPMs multiplexed, the FWHM coincident timing resolution for single [Formula: see text] mm LYSO crystals was improved from 401 ± 4 ps without filtering to 248 ± 5 ps with filtering. With 4 SiPMs multiplexed, using an array of [Formula: see text] mm LFS crystals the mean time resolution was improved from 436 ± 6 ps to 249 ± 2 ps. Position information was acquired with a novel binary positioning network. All experiments were performed at room temperature with no active temperature regulation. These results show a promising technique for the construction of high performance multiplexed TOF PET readout systems using analog leading edge timing pickoff.

Issues in data monitoring and interim analysis of trials.

OBJECTIVES: To address issues about data monitoring committees (DMCs) for randomised controlled trials (RCTs). DATA SOURCES: Electronic databases. Handsearching of selected books. Personal contacts with experts in the field. REVIEW METHODS: Systematic literature reviews of DMCs and small group processes in decision-making; sample surveys of: reports of RCTs, recently completed and ongoing RCTs and policies of major organisations involved in RCTs; case studies of four DMCs; and interviews with experienced DMC members. All focused on 23 prestated questions. RESULTS: Although still a minority, RCTs increasingly have DMCs. There is wide agreement that nearly all trials need some form of data monitoring. Central to the role of the DMC is monitoring accumulating evidence related to benefit and toxicity; variation in emphasis has been reflected in the plethora of names. DMCs for trials performed for regulatory purposes should be aware of any special requirements and regulatory consequences. Advantages were identified for both larger and smaller DMCs. There is general agreement that a DMC should be independent and multidisciplinary. Consumer and ethicist membership is controversial. The chair is recognised as being particularly influential, and likely to be most effective if he or she is experienced, understands both statistical and clinical issues, and is facilitating in style and impartial. There is no evidence available to judge suggested approaches to training. The review suggested that costs should be covered, but other rewards must be so minimal as to not affect decision-making. It is usual to have a minimum frequency of DMC meetings, with evidence that face-to-face meetings are preferable. It is common to have open sessions and a closed session. A report to a DMC should cover benefits and risks in a balanced way, summarised in an accessible style, avoiding excessive detail, and be as current as possible. Disadvantages of blinded analyses seem to outweigh advantages. Information about comparable studies should be included, although interaction with the DMCs of similar ongoing trials is controversial. A range of formal statistical approaches can be used, although this is only one of a number of considerations. DMCs usually reach decisions by consensus, but other approaches are sometimes used. The general, but not unanimous, view is that DMCs should be advisory rather than executive on the basis that it is the trial organisers who are ultimately responsible for the conduct of the trial. CONCLUSIONS: Some form of data monitoring should be considered for all RCTs, with reasons given where there is no DMC or when any member is not independent. An early DMC meeting is helpful, determining roles and responsibilities; planned operations can be agreed with investigators and sponsors/funders. A template for a DMC charter is suggested. Competing interests should be declared. DMC size (commonly three to eight people) is chosen to optimise performance. Members are usually independent and drawn from appropriate backgrounds, and some, particularly the chair, are experienced. A minimum frequency of meetings is usually agreed, with flexibility for more if needed. The DMC should understand and agree the statistical approach (and guidelines) chosen, with both the DMC statistician and analysis statistician competent to apply the method. A DMC's primary purpose is to ensure that continuing a trial according to its protocol is ethical, taking account of both individual and collective ethics. A broader remit in respect of wider ethical issues is controversial; arguably, these are primarily the responsibility of research ethics committees, trial steering committees and investigators. The DMC should know the range of recommendations or decisions open to it, in advance. A record should be kept describing the key issues discussed and the rationale for decisions taken. Errors are likely to be reduced if a DMC makes a thorough review of the evidence and has a clear understanding of how it should function, there is active participation by all members, differences are resolved through discussion and there is systematic consideration of the various decision options. DMCs should be encouraged to comment on draft final trial reports. These should include information about the data monitoring process and detail the DMC membership. It is recommended that groups responsible for data monitoring be given the standard name 'Data Monitoring Committee' (DMC). Areas for further research include: widening DMC membership beyond clinicians, trialists and statisticians; initiatives to train DMC members; methods of DMC decision-making; 'open' data monitoring; DMCs covering a portfolio of trials rather than single trials; DMC size and membership, incorporating issues of group dynamics; empirical study of the workings of DMCs and their decision-making, and which trials should or should not have a DMC.

Open retropubic colposuspension for urinary incontinence in women.

BACKGROUND: Urinary incontinence is a common and potentially debilitating problem. Open retropubic colposuspension is a surgical treatment which involves lifting the tissues near the bladder neck and proximal urethra in the area behind the anterior pubic bones to correct deficient urethral closure. OBJECTIVES: To assess the effects of open retropubic colposuspension for the treatment of urinary incontinence. SEARCH STRATEGY: We searched the Cochrane Incontinence Group specialised register (searched 30 June 2004)and reference lists of relevant articles. We contacted investigators to locate extra studies. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials in women with symptoms or urodynamic diagnoses of stress or mixed incontinence that included open retropubic colposuspension surgery in at least one trial group. DATA COLLECTION AND ANALYSIS: Studies were evaluated for methodological quality and appropriateness for inclusion and data extracted by two of the reviewers. Trial data were analysed by intervention. Where appropriate, a summary statistic was calculated. MAIN RESULTS: This review included 39 trials involving a total of 3301 women. Overall cure rates were 68.9% to 88.0% for open retropubic colposuspension. Two small studies suggest lower failure rates after open retropubic colposuspension than conservative treatment. Similarly, one trial suggests lower failure rates after open retropubic colposuspension compared to anticholinergic treatment. Evidence from six trials showed a lower failure rate for subjective cure after open retropubic colposuspension than after anterior colporrhaphy. Such benefit was maintained over time (RR of failure 0.51; 95% CI 0.34 to 0.76 before the first year, RR 0.43; 95% CI 0.32 to 0.57 at one to five years, RR 0.49; 95% CI 0.32 to 0.75 in periods beyond 5 years). In comparison with needle suspensions there was a lower failure rate after colposuspension in the first year after surgery (RR 0.66; 95% CI 0.42 to 1.03), after the first year (RR 0.48; 95% CI 0.33 to 0.71), and beyond five years (RR 0.32; 95% CI 15 to 0.71). Evidence from twelve trials in comparison with suburethral slings found no significant difference in failure rates in all time periods assessed. Patient-reported failure rates in short-, medium- and long-term follow-up showed no significant difference between open and laparoscopic retropubic colposuspension, but with wide confidence intervals. In two trials failure was less common after Burch (RR 0.38 95% CI 0.18 to 0.76) than after the Marshall Marchetti Krantz procedure at one to five year follow-up. There were few data at any other follow-up time.In general, the evidence available does not show a higher morbidity or complication rate with open retropubic colposuspension, compared to the other open surgical techniques, although pelvic organ prolapse is more common than after anterior colporrhaphy and sling procedures. AUTHORS' CONCLUSIONS: The evidence available indicates that open retropubic colposuspension is an effective treatment modality for stress urinary incontinence especially in the long term. Within the first year of treatment, the overall continence rate is approximately 85-90%. After five years, approximately 70% patients can expect to be dry. Newer minimal access procedures like tension free vaginal tape look promising in comparison with open colposuspension but their long-term performance is not known and closer monitoring of its adverse event profile must be done. Laparoscopic colposuspension should allow speedier recovery but its relative safety and effectiveness is not known yet.

Transabdominal pre-peritoneal (TAPP) vs totally extraperitoneal (TEP) laparoscopic techniques for inguinal hernia repair.

BACKGROUND: The choice of approach to the laparoscopic repair of inguinal hernia is controversial. There is a scarcity of data comparing the laparoscopic transabdominal preperitoneal (TAPP) approach with the laparoscopic totally extraperitoneal (TEP) approach and questions remain about their relative merits and risks. OBJECTIVES: To compare the clinical effectiveness and relative efficiency of laparoscopic TAPP and laparoscopic TEP for inguinal hernia repair. SEARCH STRATEGY: We searched Medline Extra, Embase, Biosis, Science Citation Index, Cochrane Central Register of Controlled Trials (CENTRAL), Journals@ Ovid Full Text and the electronic version of the journal, Surgical Endoscopy. Recent conference proceedings by the following organisations were hand searched: Association of Endoscopic Surgeons of Great Britain & Ireland; International Congress of the European Association for Endoscopic Surgery; Scientific Session of the Society of American Gastrointestinal & Endoscopic Surgeons (SAGES); and the Italian Society of Endoscopic Surgery. In addition, specialists involved in research on the repair of inguinal hernia were contacted to ask for information about any further completed and ongoing trials, relevant websites were searched and reference lists of the all included studies were checked for additional reports. SELECTION CRITERIA: All published and unpublished randomised controlled trials and quasi-randomised controlled trials comparing laparoscopic TAPP with laparoscopic TEP for inguinal hernia repair were eligible for inclusion. Non-randomised prospective studies were also eligible for inclusion to provide further comparative evidence of complications and adverse events. DATA COLLECTION AND ANALYSIS: Statistical analyses were performed using the fixed effects model and the results expressed as relative risk (RR) for dichotomous outcomes and weighted mean difference (WMD) for continuous outcomes with 95% confidence intervals (CI). MAIN RESULTS: The search identified one RCT which reported no statistical difference between TAPP and TEP when considering duration of operation, haematoma, length of stay, time to return to usual activity and recurrence. The eight non-randomised studies suggest that TAPP is associated with higher rates of port-site hernias and visceral injuries whilst there appear to be more conversions with TEP. Vascular injuries and deep/mesh infections were rare and there was no obvious difference between the groups. No studies reporting economic evidence were identified. Very limited data were available on learning effects but these data suggest that operators become experienced at between 30 and 100 procedures. AUTHORS' CONCLUSIONS: There is insufficient data to allow conclusions to be drawn about the relative effectiveness of TEP compared with TAPP. Efforts should be made to start and complete adequately powered RCTs, which compare the different methods of laparoscopic repair.

Effects of weight loss in overweight/obese individuals and long-term lipid outcomes--a systematic review.

This paper aims to review the evidence for long-term effectiveness of weight loss on cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglycerides in overweight/obese people. Current evidence is mostly based on short-term studies. A systematic review of long-term lipid outcomes of weight loss in studies published between 1966 and 2001, was conducted. Inclusion criteria included all cohort studies and trials carried out on participants with body mass index of greater than or equal to 28 kg m(-2). Studies had at least two weight change measurements and follow-up of more than 2 years. Thirteen long-term studies with a follow-up of more than 2 years were included. Cholesterol has a significant positive linear relationship with weight change (r = 0.89) where change in weight explains about 80% of the cholesterol difference variation (Adj R2 = 0.80). For every 10 kg weight loss a drop of 0.23 mmol L(-1) in cholesterol may be expected for a person suffering from obesity or are grossly overweight. Weight loss has long-term beneficial effects especially on LDL and cholesterol. Weight loss in obese patients should be encouraged and sustained.

Overview of expression of matrix metalloproteinases (MMP-17, MMP-18, and MMP-20) in cultured human cells.

We recently described the cell type distribution of several matrix metalloproteinases (MMP-1 through MMP-16). In this report we extend this study by analysis of three recently described MMPs. PCR primers for MMP-17, MMP-18, and MMP-20 were optimized for use in RT-PCR. The results demonstrate one or more cell lines or tissue that express mRNA for each of these newly described MMPs.

Lessons for search strategies from a systematic review, in The Cochrane Library, of nutritional supplementation trials in patients after hip fracture.

BACKGROUND: A key aim when conducting systematic reviews of randomized controlled trials (RCTs) is to include all of the evidence, if possible. Serious bias may result if trials are missed through inadequate search strategies. OBJECTIVE: The objective was to evaluate the search plan for identifying RCTs in nutrition as part of a systematic review, in The Cochrane Library, of nutritional supplementation trials in patients after hip fracture. DESIGN: We identified potential studies by searching the electronic databases BIOSIS, CABNAR, CINAHL, EMBASE, HEALTHSTAR, and MEDLINE; reference lists in trial reports; and other relevant articles. We also contacted investigators and other experts for information and searched 4 nutrition journals by hand. RESULTS: We identified 15 RCTs that met the predefined inclusion criteria. The search plan identified 8 trials each in EMBASE, HEALTHSTAR, and MEDLINE and 7 in BIOSIS and CABNAR. BIOSIS was the only electronic database source of 2 trials. Eleven trials were identified by searching electronic databases and 2 unpublished trials were identified via experts in the field. We found one trial, published only as a conference abstract, by searching nutrition journals by hand. After publication of the protocol for the review in The Cochrane Library, we were informed of another unpublished trial. CONCLUSIONS: We found that a limited search plan based on only MEDLINE or one of the other commonly available databases would have failed to locate nearly one-half of the studies. To protect against bias, the search plan for a systematic review of nutritional interventions should be comprehensive.

Novel inhibitors of potassium ion channels on human T lymphocytes.

The in vitro biological characterization of a series of 4-(alkylamino)-1,4-dihydroquinolines is reported. These compounds are novel inhibitors of voltage-activated n-type potassium ion (K+) channels in human T lymphocytes. This series, identified from random screening, was found to inhibit [125I]charybdotoxin binding to n-type K+ channels with IC50 values ranging from 10(-6) to 10(-8) M. These analogs also inhibit whole cell n-type K+ currents with IC50 values from 10(-5) to 10(-7) M. The preparation of a series of new 4-(alkylamino)-1,4-dihydroquinolines is described. Structure-activity relationships are discussed. Naphthyl analog 7c, the best compound prepared, exhibited > 100-fold selectivity for inhibition of [125I]charybdotoxin binding to n-type K+ channels compared with inhibition of [3H]dofetilide binding to cardiac K+ channels. These compounds represent a potent and selective series of n-type K+ channel inhibitors that have the potential for further development as anti-inflammatory agents.

RT-PCR without RNA isolation.

Reverse transcription-PCR (RT-PCR) has traditionally required time-consuming RNA extraction and purification. This report demonstrates that one can completely avoid the RNA extraction step in RT-PCR by basing the comparison of samples on cell number rather than micrograms of total RNA. A new method for lysing cells while preserving RNA is described. RT-PCR is carried out (i) by rapidly freezing cells in the presence of ribonuclease inhibitor (RNase inhibitor) plus dithiothreitol and (ii) by using extracts of 250 or fewer cells directly in the RT-PCR assay. Aldolase mRNA, extracted by freeze-thawing cells in the presence of RNase inhibitor, was found to be stable at 42 degrees C for over three hours. Since the RT step can be completed within 1 h, there is minimal degradation of mRNA. This simple procedure avoids the use of harsh reagents, which may inhibit enzymes involved in RT-PCR, and produces results virtually identical to methods that employ guanidinium thiocyanate and phenol for RNA extraction. Optimized conditions for each parameter of the procedure are described that permit amplification of mRNA from as few as four cells.

When and how to assess fast-changing technologies: a comparative study of medical applications of four generic technologies.

OBJECTIVES. To try to identify the optimal time at which to start assessing new and fast-evolving health technologies. To provide insight into factors influencing the timing of assessments and the choice of methods for assessing new and fast-changing technologies. HOW THE RESEARCH WAS CONDUCTED. A series of literature reviews were undertaken covering the general principles involved in the timing of health technology assessments (HTAs). Additionally, the reported assessments of laparoscopic cholecystectomy, chorionic villus sampling (CVS), teleradiology, teledermatology, genetic screening for predisposition to breast cancer, and gene therapy for cystic fibrosis were reviewed to try to identify the factors that influenced the timing of these assessments. Key individuals in each field were also interviewed. The selected technologies allowed comparison between those that were new and evolving and those that were relatively well-established. A bibliometric study of publication trends was also undertaken to see whether these trends would suggest points in the development of a technology that could be used as indicators that assessment should be started. RESEARCH FINDINGS. TIMING. The precise point at which assessment should start was not identified but the bibliometric study suggested that extending this approach might give useful results. For all health technologies, more regular reporting of outcomes and side-effects should be encouraged during the period after initial assessment and, where the technology is fast-changing, reassessment should take place from time to time. The precise intervals were not identified and the problem remains of deciding when a technology has changed enough to warrant reassessment. FACTORS INFLUENCING TIMING. Published reports of assessments did not generally specify the reasons for their timing, but a number of factors appear to have influenced the timing of those assessments, directly or indirectly. Product champions and opinion leaders pioneer the introduction of new technologies into clinical practice, and their reports may lead to the rapid diffusion of such technologies before they have been adequately evaluated, as was the case with laparoscopic cholecystectomy; this diffusion may limit the methods of evaluation that can then be used. It is therefore important to assess new health technologies before diffusion takes place. The extent to which regulatory control is imposed on the introduction of new health technologies can also influence the timing of assessments. Such controls might have helped to restrict the diffusion of laparoscopic cholecystectomy, making a large and widely generalisable randomised controlled trial (RCT) feasible. The source and availability of funding for studies may influence the nature and timing of trials. Many telemedicine evaluations were funded by commercial telecommunications organisations and were thus restricted in their timing (and biased towards the technological aspects of the applications) by the availability of funds. Media coverage undoubtedly has an influence although this influence is not always predictable; it may generate 'favourable' publicity about new health technologies, which can lead to immediate demands for the new technique, as was the case with laparosocpic cholecystectomy with its apparent benefits. Thus assessments should be made before media coverage exerts popular pressure on purchasers to adopt the technology and dissuades patients from participating in RCTs (because of fear they may be randomised to the standard treatment as occurred in a US trial of CVS). Innovators should also be cautious in the claims that they make to the media.(ABSTRACT TRUNCATED)

Statistical assessment of the learning curves of health technologies.

OBJECTIVES: (1) To describe systematically studies that directly assessed the learning curve effect of health technologies. (2) Systematically to identify 'novel' statistical techniques applied to learning curve data in other fields, such as psychology and manufacturing. (3) To test these statistical techniques in data sets from studies of varying designs to assess health technologies in which learning curve effects are known to exist. METHODS - STUDY SELECTION (HEALTH TECHNOLOGY ASSESSMENT LITERATURE REVIEW): For a study to be included, it had to include a formal analysis of the learning curve of a health technology using a graphical, tabular or statistical technique. METHODS - STUDY SELECTION (NON-HEALTH TECHNOLOGY ASSESSMENT LITERATURE SEARCH): For a study to be included, it had to include a formal assessment of a learning curve using a statistical technique that had not been identified in the previous search. METHODS - DATA SOURCES: Six clinical and 16 non-clinical biomedical databases were searched. A limited amount of handsearching and scanning of reference lists was also undertaken. METHODS - DATA EXTRACTION (HEALTH TECHNOLOGY ASSESSMENT LITERATURE REVIEW): A number of study characteristics were abstracted from the papers such as study design, study size, number of operators and the statistical method used. METHODS - DATA EXTRACTION (NON-HEALTH TECHNOLOGY ASSESSMENT LITERATURE SEARCH): The new statistical techniques identified were categorised into four subgroups of increasing complexity: exploratory data analysis; simple series data analysis; complex data structure analysis, generic techniques. METHODS - TESTING OF STATISTICAL METHODS: Some of the statistical methods identified in the systematic searches for single (simple) operator series data and for multiple (complex) operator series data were illustrated and explored using three data sets. The first was a case series of 190 consecutive laparoscopic fundoplication procedures performed by a single surgeon; the second was a case series of consecutive laparoscopic cholecystectomy procedures performed by ten surgeons; the third was randomised trial data derived from the laparoscopic procedure arm of a multicentre trial of groin hernia repair, supplemented by data from non-randomised operations performed during the trial. RESULTS - HEALTH TECHNOLOGY ASSESSMENT LITERATURE REVIEW: Of 4571 abstracts identified, 272 (6%) were later included in the study after review of the full paper. Some 51% of studies assessed a surgical minimal access technique and 95% were case series. The statistical method used most often (60%) was splitting the data into consecutive parts (such as halves or thirds), with only 14% attempting a more formal statistical analysis. The reporting of the studies was poor, with 31% giving no details of data collection methods. RESULTS - NON-HEALTH TECHNOLOGY ASSESSMENT LITERATURE SEARCH: Of 9431 abstracts assessed, 115 (1%) were deemed appropriate for further investigation and, of these, 18 were included in the study. All of the methods for complex data sets were identified in the non-clinical literature. These were discriminant analysis, two-stage estimation of learning rates, generalised estimating equations, multilevel models, latent curve models, time series models and stochastic parameter models. In addition, eight new shapes of learning curves were identified. RESULTS - TESTING OF STATISTICAL METHODS: No one particular shape of learning curve performed significantly better than another. The performance of 'operation time' as a proxy for learning differed between the three procedures. Multilevel modelling using the laparoscopic cholecystectomy data demonstrated and measured surgeon-specific and confounding effects. The inclusion of non-randomised cases, despite the possible limitations of the method, enhanced the interpretation of learning effects. CONCLUSIONS - HEALTH TECHNOLOGY ASSESSMENT LITERATURE REVIEW: The statistical methods used for assessing learning effects in health technology assessment have been crude and the reporting of studies poor. CONCLUSIONS - NON-HEALTH TECHNOLOGY ASSESSMENT LITERATURE SEARCH: A number of statistical methods for assessing learning effects were identified that had not hitherto been used in health technology assessment. There was a hierarchy of methods for the identification and measurement of learning, and the more sophisticated methods for both have had little if any use in health technology assessment. This demonstrated the value of considering fields outside clinical research when addressing methodological issues in health technology assessment. CONCLUSIONS - TESTING OF STATISTICAL METHODS: It has been demonstrated that the portfolio of techniques identified can enhance investigations of learning curve effects. (ABSTRACT TRUNCATED)

Does early imaging influence management and improve outcome in patients with low back pain? A pragmatic randomised controlled trial.

OBJECTIVES: To establish whether the early use of sophisticated imaging techniques influences the clinical management and outcome of patients with low back pain (LBP) and whether it is cost-effective. DESIGN: A pragmatic multicentre randomised controlled trial using a standard two parallel group approach incorporating an economic evaluation. For a subgroup of trial participants, a controlled 'before and after' approach was used to assess the impact of 'early imaging' on clinicians' diagnostic and therapeutic confidence. SETTING AND PARTICIPANTS: A total of 782 participants who had been referred by their general practitioner to a consultant orthopaedic specialist or neurosurgeon because of symptomatic lumbar spine disorders. The study included 14 hospitals in Scotland and one in England over a 24-month period. RESULTS: Participants in both groups reported an improvement in health status at 8 and 24 months with the 'early imaging' group having statistically significantly better outcome. Other than the proportion of participants receiving imaging (90% versus 30%), there were few differences between the groups in the management received throughout the 24-month follow-up. The total number of outpatient consultations in the two groups was similar although more people in the 'early imaging' group had return outpatient appointments during the 8-month follow-up. Clinicians' diagnostic confidence, between trial entry and follow-up, increased significantly for both groups with a greater increase in the 'early imaging' group. The cost of imaging was the main determinant of the difference in total costs between the groups and it was estimated that 'early imaging' could provide an additional 0.07 quality-adjusted life-years (QALYs), at an additional average cost of 61 British pounds over the 24-month follow-up. Using non-imputed costs and QALYs but adjusted for baseline differences in EQ-5D score, the mean incremental cost per QALY of 'early imaging' was 870 British pounds. The results were sensitive to the costs of imaging and the confidence intervals surrounding estimates of average costs and QALYs. CONCLUSIONS: The early use of sophisticated imaging does not appear to affect management overall but does result in a slight improvement in clinical outcome at an estimated cost of 870 British pounds per QALY. Imaging was associated with an increase in clinicians' diagnostic confidence, particularly for non-specialists. Further research is required to determine if more rapid referral to sophisticated imaging and secondary care is important in the acute episode and whether the use of imaging would be more beneficial for particular categories of LBP.