A comparison of preferences for two GLP-1 products--liraglutide and exenatide--for the treatment of type 2 diabetes

OBJECTIVE

To use time trade-off (TTO) to compare patient preferences for profiles of two glucagon-like peptide (GLP-1) products for the treatment of type 2 diabetes (liraglutide and exenatide) that vary on four key attributes - efficacy (as measured by hemoglobin A(1C)), incidence of nausea, incidence of hypoglycemia, and dosing frequency (QD vs. BID) - and measure the contribution of those attributes to preferences.

METHODS

A total of 382 people with T2DM were recruited to participate in an internet-based survey consisting of a series of health-related questions, a conjoint exercise and a set of time trade-off items. In the conjoint exercise, respondents were presented with eight pairs of hypothetical GLP-1 profiles, and completed a time-tradeoff exercise for each pair.

RESULTS

The product profile representing liraglutide was preferred by 96% of respondents and resulted in significantly higher health utilities (0.038) than the product profile representing exenatide (0.978 vs. 0.94, p < 0.05). Estimated preference scores from the conjoint analysis revealed that efficacy measured by hemoglobin A(1C) is the most important attribute, followed by nausea, hypoglycemia, and dosing schedule.

LIMITATIONS

On-line participants may not represent 'typical' type 2 diabetes patients, and brief product profiles represented results from clinical trials, not clinical practice

CONCLUSION

Based on the four attributes presented, patients prefer liraglutide over exenatide. Preference is based on superior efficacy and less nausea more than less hypoglycemia and once-daily dosing.

Effectiveness and safety of a structured swimming program in previously sedentary women during pregnancy

OBJECTIVE

To determine whether undertaking a swimming program in sedentary women during pregnancy would improve maternal fitness without adverse fetal consequences.

METHODS

Prospective observational investigation of healthy sedentary pregnant women participating in a monitored swimming program.

RESULTS

Twenty-three women attended swimming sessions from 16 to 28 weeks of gestation resulting in increasing distances swum and improved aerobic fitness as measured by physical work capacity (PWC170) (p = 0.003). Resting maternal heart rate decreased (p = 0.041) and resting systolic (p = 0.092) and diastolic (p = 0.971) blood pressures remained unchanged over gestation. The mean fetal heart rates decreased with advancing gestational age (p = 0.001), consistent with normal physiology. Non-stress tests and umbilical artery systolic/diastolic ratios were similar before and after swimming sessions, providing evidence that fetal well-being was unchanged.

CONCLUSIONS

A structured swimming program in sedentary pregnant women increases maternal fitness without any alteration in maternal and fetal well-being.

Recognition of emotion from facial expression following traumatic brain injury

PRIMARY OBJECTIVE

To assess three domains of emotion recognition in people with traumatic brain injury (TBI).

RESEARCH DESIGN

A between group comparison.

PROCEDURES

Twenty-four participants with severe TBI and 15 matched participants without brain damage were asked to label and match facial expressions with and without context. The participants with TBI were also interviewed regarding changes in subjective experience of emotion.

MAIN OUTCOMES AND RESULTS

Participants with TBI were found to be significantly impaired on expression labelling and matching, but experienced some improvement when provided with context. Negative emotions were particularly affected. Affective semantic knowledge and face perception appeared to be relatively intact in this group. The majority of participants with TBI reported some change in the post-injury experience of everyday emotion, although the pattern of changes differed greatly between individuals. Reduced subjective experience, especially of sadness and fear, was associated with poor emotion matching but not emotion labelling.

Material Orientation Artifact Studies in Magnetic Resonance Imaging

With the increased interest of MRI guided interventional procedures in modern medical treatments, image distortion and artifact formation based on material selection and orientation within the MRI scanner are central concerns for precise object localization. The goal of this study was to illustrate the artifact behavior of materials with various magnetic susceptibilities and radio frequency conductivity values corresponding to object orientation relative to the primary magnetic field. To test the effects of orientation on image distortion and image artifacts, 0.125 inch cylindrical test samples of various materials were imaged using a clinical Siemens 3 Tesla MR scanner. Modern medical instrumentation and surgical utensils are typically made from highly paramagnetic materials (e.g., titanium, nitinol, or stainless steel) which also have high RF conductivities. The combination of these two material properties cause both primary magnetic field (B0) and RF field (B1) inhomogeneities which lead to local image distortions. A change in the local magnetic field induces errors within the slice selection gradient, as the precessional frequency of the proton nuclei in the desired region of interest will not correspond to the exact spatial location on the object and will excite a broader region due to the RF conductivity of the material. Conversely to more traditional surgical materials, diamagnetic materials (e.g., bismuth, pyrolytic carbon, water, most plastics) are free from the susceptibility artifacts due to B0 inhomogeneities and thus offer a level of MR compatibility that traditional materials cannot. A specific testing phantom was built to fit a clinical wrist coil. The phantom consisted of an aqueous solution of gadolinium and copper sulfate to increase image contrast and a rotatable turret post for sample positioning. The particular materials studied were chosen to demonstrate the wide variation in both magnetic susceptibility values and RF conductivities (e.g., 6A1-4V titanium, 316L stainless steel, carbon fiber, 6061 T6 aluminum, brass, copper, beryllium copper). ImageJ software measured the overall pixel area and major dimension of each MR image artifact at 0, 45, and 90 degree orientations of each test sample relative to B0. The results of the measurements indicated measurable increases in signal are of the paramagnetic and highly conductive test specimens orientated orthogonal to the primary magnetic field. For instance, two common medical grade materials such as 316L stainless steel and 6Al-4V titanium resulted in artifact area increases of 770±10% and 234±10%, respectively, relative to the actual cross sectional area of the sample. Conversely, the more diamagnetic materials, carbon fiber and beryllium copper demonstrated increased artifact areas of 8±10% and 12±10%, respectively. Errors in artifact area percentage growth measurement are primarily attributed to manual image segmentation and variation in coil positioning within the MRI bore. The results indicate that MR image artifact size and object distortion characteristics can be influenced by both material selection and object orientation relative to the primary magnetic field. In the interest of accurate navigation of image guided equipment and devices, interventional devices should be tested for image distortion in multiple orientations. This work is supported by MIMTeC, a National Science Foundation Industry University Collaborative Research Center and by NIH Grant P30 NS057091.

Use of Colloidal Graphite Coating to Reduce Magnetic Resonance Imaging Artifacts Caused by Metallic Objects

Magnetic susceptibility mismatch, between human tissue and a foreign metallic object, is one of several factors responsible for image distortions in magnetic resonance imaging (MRI). Combining diamagnetic materials such as bismuth or carbon with paramagnetic materials such as nitinol or titanium can reduce the mismatch in bulk susceptibility of a foreign object and the surrounding tissue. Muller-Bierl et al. have succeeded in reducing MRI field distortion by coating titanium wire with bismuth. Wilson et al. used a pyrolytic graphite mouth shim to improve brain functional MRI performance. Conolly et al. have successfully used pyrolytic graphite in foam to reduce image artifacts at air-tissue interfaces. In this study, it was hypothesized that coating a metallic object with carbon particles suspended in a polymer can reduce the size of image artifacts. Four 6Al-4V titanium discs (2.3mm×9.5mm∅) were encapsulated in an epoxy-graphite mixture. Mixtures of graphite and epoxy were poured around the titanium discs in molds and allowed to cure. A specimen of titanium was encapsulated in plain epoxy to serve as the control sample. Polycrystalline graphite was mixed at mass ratios of 1:2 and 1:1 to epoxy for two of the samples. Pyrolytic graphite flakes were mixed at a 1:2 mass ratio to epoxy. The sample discs were placed in an aqueous solution of copper sulfate and gadolinium contrast agent inside a wrist imaging coil at the isocenter of a 3 Tesla MRI machine; disc axes were perpendicular to the B0 direction. A T2-weighted gradient echo MRI image was taken in the coronal plane. Echo time, relaxation time, flip angle, and phase encode direction set to 71 ms, 3430 ms, 80 degrees, and right to left respectively. The control sample produced an arrowhead artifact sweeping in the same direction as the static magnetic field vector, B0. The two samples containing powdered polycrystalline graphite produced arrowhead shaped artifacts. The direction of image distortion, however, was opposite from that of the control sample. The change in direction of the image artifact is attributed to the change in bulk magnetic susceptibility of the sample from paramagnetic behavior of titanium encapsulated in plain epoxy to a diamagnetic behavior from the added carbon powder. The titanium sample encapsulated in the pyrolytic graphite-epoxy mixture produced an artifact with irregular outline and no discernable directional bias relative to B0. The hypothesized cause for this difference in artifact shape between the polycrystalline and pyrolytic graphite samples is an increase in air bubble entrapment due to the planar structure of the pyrolytic graphite flakes during the epoxy mixing process. Further study is underway to find a specific carbon-polymer mass ratio and coating thickness that will reduce MR image artifacts that would otherwise appear due to the presence of a metallic object in the MRI region of interest. This work is supported by MIMTeC, a National Science Foundation Industry University Collaborative Research Center and by NIH Grant P30NS057091.

First Report of Brown Ring Patch Caused by Waitea circinata var. circinata on Poa annua in Virginia

Brown ring patch was first described as a disease of cool-season turfgrass on creeping bentgrass (Agrostis palustris) (4) in Japan and later reported in California on annual bluegrass (Poa annua) (2). Brown ring patch symptoms were observed beginning in December 2007 through spring 2008 on 6 of 18 putting greens on a golf course in Reston, VA. Symptoms included yellow rings and patches of blighted turfgrass on the mixed stands of creeping bentgrass (A. palustris) and primarily annual bluegrass (Poa annua). Chlorosis and blight occurred predominantly on P. annua. A turfgrass sample was received from a consultant in April 2008, and disease severity on affected greens was estimated to be 40%. After incubating for 2 days in a moist chamber, Rhizoctonia-like aerial mycelia were observed. The pathogen was isolated on water agar and potato dextrose agar amended with thiophanate-methyl (100 mg/L), rifampicin (100 mg/L), and ampicillin (500 mg/L) from P. annua plants that had been surface sterilized with 70% ethanol for 15 s. Colony and sclerotia morphology were consistent with Waitea circinata var. circinata as previously described (2,4). Hyphae were stained with aniline blue and multiple nuclei were observed per cell. The teleomorph was not observed on plant material or in culture. Amplified fragments of rDNA including internal transcribed spacers from the isolate were amplified in three bacterial clones and sequenced bidirectionally (GenBank Accession Nos. FJ154894, FJ154895, and FJ154896) using primers ITS1/ITS4 (2,4). The consensus sequences matched, with 99% homology and 99% sequence overlap, isolate TRGC1.1 of W. circinata var. circinata (GenBank Accession No. DQ900586) (2). Annual bluegrass was not available for use in performing Koch's postulates, but previous studies have shown that W. circinata var. circinata is pathogenic to roughstalk bluegrass (P. trivialis) (1,3). Pots of P. trivialis cv. Cypress that were 1 week postemergence were inoculated with seven wheat grains that had been autoclaved and then infested with the isolate. Plants were incubated at 25°C in a sealed plastic bag with a moist paper towel on the bottom. Hyphae grew from the grains and colonized the grass. Individual plants began to turn chlorotic within 3 days, and more than 80% of the turf in pots was dead after 1 week. Control pots were inoculated with autoclaved wheat seed and showed no disease symptoms after 1 week. Inoculations were repeated twice more with the same results. W. circinata var. circinata was reisolated from affected plants in all replications of the test. To our knowledge, this is the first report of brown ring patch in Virginia. Additional research is needed to assess the prevalence and importance of this disease on golf course putting greens in Virginia. References: (1) C. M. Chen et al. Plant Dis. 91:1687, 2007. (2) K. A. de la Cerda et al. Plant Dis. 91:791, 2007. (3) N. Flor et al. Plant Dis. 92:1586, 2008. (4) T. Toda et al. Plant Dis. 89:536, 2005.

Brachiopod punctae: a complexity in shell biomineralisation

Perforations ("punctae") are one of the most characteristic morphological shell features in calcite brachiopods. The significance of punctae is that they represent discontinuities in shell biomineralisation and thus add a level of complexity that must be accounted for in any model of brachiopod shell formation. A significant hindrance to understanding punctae growth and formation is the absence of sufficient information on volume, size and density. Here, we use synchrotron-radiation X-ray tomographic microscopy (SRXTM) to obtain three-dimensional information about punctae of five species of calcite brachiopods. X-ray tomography shows that punctae morphology is species-specific and reveals previously unknown levels of complexity for each species. This information is combined with previous data on morphology to discuss the function and growth of punctae. Overall the present study demonstrates the need to increase our understanding of discontinuities and the role of cell biology in the context of biomineralisation.

Determination of odour threshold concentration ranges for some disinfectants and disinfection by-products for an Australian panel

Taste-and-odour complaints are a leading cause of consumer dissatisfaction with drinking water. The aim of this study was to determine odour threshold concentration ranges and descriptors, using a Western Australian odour panel, for chlorine, bromine, chlorine added to bromide ions, the four major regulated trihalomethanes (THMs), and combined THMs. An odour panel was established and trained to determine odour threshold concentration ranges for odorous compounds typically found in drinking water at 25 degrees C, using modified flavour profile analysis (FPA) techniques. Bromine and chlorine had the same odour threshold concentration ranges and were both described as having a chlorinous odour by a majority of panellists, but the odour threshold concentration range of bromine expressed in free chlorine equivalents was lower that that of chlorine. It is likely that the free chlorine equivalent residuals measured in many parts of distribution systems in Western Australia are comprised of some portion of bromine and that bromine has the potential to cause chlorinous odours at a lower free chlorine equivalent concentration than chlorine itself. In fact, bromine is the likely cause of any chlorinous odours in Western Australian distributed waters when the free chlorine equivalent concentration is between 0.04 and 0.1 mg L(-1). Odour threshold concentrations for the four individual THMs ranged from 0.06-0.16 mg L(-1), and the odour threshold concentration range was 0.10 + or - 0.09 mg L(-1) when the four THMs were combined (in equal mass concentrations). These concentrations are below the maximum guideline value for total THM concentration in Australia so odours from these compounds may possibly be observed in distributed waters. However, while the presence of THMs may contribute to any sweet/fragrant/floral and chemical/hydrocarbon odours in local drinking waters, the THMs are unlikely to contribute to chlorinous odours.

Gastric stasis occurs in spontaneous, visually induced, and interictal migraine

OBJECTIVE

To evaluate and compare gastric motility and emptying during spontaneous migraine to previous observations from induced migraine.

BACKGROUND

We have previously demonstrated a delay in gastric emptying both during the interictal period and during an induced migraine. A limitation noted in these studies was whether there are differences gastrointestinally during a visually induced migraine compared to spontaneous migraines. To address this, 9 additional studies have been performed to ascertain if there is a similar delay during spontaneous migraine

METHODS

Gastric scintigraphy using a standard meal was performed in 3 subjects during 3 periods: spontaneous migraine, induced migraine, and interictal period.

RESULTS

On average, the time to half emptying was delayed during spontaneous migraine (124 minutes), during induced migraine (182 minutes), and during the interictal period migraine (243 minutes) compared to normative values established at our center (112 minutes). On average, similar gastric slowing was seen in all 3 groups when the percentage of nuclear material remaining in the stomach at 2 hours was measured.

CONCLUSIONS

This study provides additional evidence of gastric stasis in migraineurs interictally during induced and spontaneous migraine.

Maternal physiological responses to swimming training during the second trimester of pregnancy

Maternal submaximal aerobic fitness (PWC170) was measured before, during, and after 12 weeks of swimming training during the second trimester of pregnancy in 23 sedentary women. For comparison, 11 women maintained their normal activities, but did not swim. Training sessions were 3 times per week for 40 min, producing heart rate (HR) responses of 65%-70% of estimated maximum HR and increases in rectal temperature (n = 8) of approximately 0.4 degrees C. Distance swum per session almost doubled over the training period (581 +/- 177 m to 1110 +/- 263 m). PWC170 of the nonswimming group remained stable over time; that of the swimming group increased significantly by 13.8% after 8 weeks of training (790 +/- 145 to 909 +/- 137 kpm/min; p = 0.026). The results indicate that a significant aerobic training effect can be achieved by light-moderate-intensity swimming during pregnancy in previously sedentary women. Further, all women remained healthy, with no adverse outcomes for mother or baby.

Management of the third stage of labor

Management of the third stage of labor has been an issue of discussion, concern, and continued debate for the past two decades. Despite the many strategies employed and the divergent approaches to care and philosophies espoused, there has not been a significant, consistent reduction in the postpartum hemorrhage rates reported in industrialized countries in recent times. This article explores the strategies that have been and are currently being used in an effort to reduce the risk of postpartum hemorrhage.

Sumatriptan/Naproxen Sodium for Migraine: Efficacy, Health Related Quality of Life, and Satisfaction Outcomes

OBJECTIVE

To describe the pain relief, satisfaction, and health-related quality of life results of moderate or severe migraines treated with a sumatriptan/naproxen sodium combination tablet.

METHODS

Sumatriptan and naproxen sodium as a single-dose formulation tablet was used to treat moderate to severe migraines over a 12-month period in a phase 3, open-label, multicenter study (n = 565) in patients with at least 6 months' history of migraine headaches.

RESULTS

Seventy percent of all attacks were treated with 1 dose of sumatriptan/naproxen sodium. Overall subjects treated 24,485 attacks; of these, 81% attacks achieved pain relief and 60% pain-free by 2 hours. At 3 months, the percentage of patients satisfied or very satisfied increased from baseline on all 8 Patient Perception of Migraine Questionnaire (PPMQ) items and remained high throughout the study. Mean Migraine-Specific Quality of Life Questionnaire (MSQ) domain scores also increased by 13-15 points from baseline during this time and remained high.

CONCLUSIONS

Sumatriptan/naproxen sodium provides consistent relief of migraine attacks over 12 months, resulting in improved patient satisfaction and migraine specific quality of life.

Kidney transplant rejection in Australia and New Zealand: relationships between rejection and graft outcome

Although acute rejection rates have fallen over time, how this relates to graft outcomes is not known. Using data from the ANZDATA Registry, we examined associations of rejection within six months of transplantation with graft and patient outcomes among kidney-only transplants performed between April 1997 and December 2004 in Australia and New Zealand. Associations of biopsy histology with outcomes of the rejection episode were also examined. Outcomes were examined among 4325 grafts with 1961 rejection episodes in total. Crude rejection rates have fallen by one-third over that time, but rates of graft survival are constant. The occurrence of acute rejection was associated with an increased risk of graft loss after 6 months (HR, adjusted for donor and recipient characteristics, 1.69 [1.36-2.11], p<0.001). Late rejection (first rejection >or=90 days) was associated with higher risk of graft loss (adjusted HR 2.46 [1.70-3.56], p<0.001). Vascular rejection was also associated with a higher risk of graft loss 2.07 [95% CI 1.60-2.68], p<0.001. The occurrence of acute rejection is associated with an ongoing increased risk of graft loss, particularly if that episode occurred late or included vascular rejection. The reduced rates of rejection have not been associated with improved graft survival.

Grey literature in meta-analyses of randomized trials of health care interventions

BACKGROUND

The inclusion of grey literature (i.e. literature that has not been formally published) in systematic reviews may help to overcome some of the problems of publication bias, which can arise due to the selective availability of data.

OBJECTIVES

To review systematically research studies, which have investigated the impact of grey literature in meta-analyses of randomized trials of health care interventions.

SEARCH STRATEGY

We searched the Cochrane Methodology Register (The Cochrane Library Issue 3, 2005), MEDLINE (1966 to 20 May 2005), the Science Citation Index (June 2005) and contacted researchers who may have carried out relevant studies.

SELECTION CRITERIA

A study was considered eligible for this review if it compared the effect of the inclusion and exclusion of grey literature on the results of a cohort of meta-analyses of randomized trials.

DATA COLLECTION AND ANALYSIS

Data were extracted from each report independently by two reviewers. The main outcome measure was an estimate of the impact of trials from the grey literature on the pooled effect estimates of the meta-analyses. Information was also collected on the area of health care, the number of meta-analyses, the number of trials, the number of trial participants, the year of publication of the trials, the language and country of publication of the trials, the number and type of grey and published literature, and methodological quality.

MAIN RESULTS

Five studies met the inclusion criteria. All five studies showed that published trials showed an overall greater treatment effect than grey trials. This difference was statistically significant in one of the five studies. Data could be combined for three of the five studies. This showed that, on average, published trials showed a 9% greater treatment effect than grey trials (ratio of odds ratios for grey versus published trials 1.09; 95% CI 1.03-1.16). Overall there were more published trials included in the meta-analyses than grey trials (median 224 (IQR 108-365) versus 45(IQR 40-102)). Published trials had more participants on average. The most common types of grey literature were abstracts (55%) and unpublished data (30%). There is limited evidence to show whether grey trials are of poorer methodological quality than published trials.

AUTHORS' CONCLUSIONS

This review shows that published trials tend to be larger and show an overall greater treatment effect than grey trials. This has important implications for reviewers who need to ensure they identify grey trials, in order to minimise the risk of introducing bias into their review.

Development and preliminary psychometric testing of the Multidimensional Assessment of Pain Scale: MAPS

BACKGROUND

This study aimed to test the preliminary psychometric properties of the Multidimensional Assessment Pain Scale (MAPS), a clinical instrument developed for assessing postoperative pain in critically ill preverbal children.

METHODS

The MAPS was developed using pain indicators observed in postoperative critically ill infants. Content validity was established by a panel of experts. The scale was tested for validity and reliability in 43 postoperative children aged 0-31 months admitted to the pediatric intensive care units of two tertiary referral hospitals. Pain was measured concurrently by three independent assessors using the MAPS, the Face, Leg, Activity, Cry, and Consolability scale (FLACC) and the Visual Analog Scale (VAS) to assess concurrent and convergent validity.

RESULTS

Internal consistency was moderate (r = 0.68). Interrater reliability of the MAPS was good (kappa: 0.68-0.84) for all categories and moderate for breathing pattern (kappa = 0.54). Excellent interrater reliability was shown for total MAPS (intraclass correlation 0.91). Agreement measurements between MAPS and FLACC, and MAPS and VAS showed that the risk of measurement error was small.

CONCLUSION

Although initial psychometric testing of the MAPS shows promising results, the tool requires further psychometric testing, including responsiveness to analgesic effect (currently in progress).

Efficacy of Gyrus diego microdissector at varying oscillation speeds

OBJECTIVE

To determine the efficacy of the Gyrus diego microdissector at increasing oscillation speeds, using an in vitro tissue model.

BACKGROUND

It had not previously been established whether microdissectors were more efficient at higher or lower speeds.

METHODS

We investigated the effect of varying microdissector oscillation speeds on the weight of material aspirated in a given time. A 4 mm straight blade was used with constant suction strength. Jelly and liver were used to simulate polyps and muscle plus connective tissue, respectively. Water was used as a control. Repeat readings were taken at speeds of 1000, 2000, 3000, 4000 and 5000 rpm. Data were analysed using linear bivariate regression.

RESULTS

The results showed significant linear trends in the cases of liver and jelly, with faster cutter speeds being associated with higher aspiration rates.

CONCLUSION

These results suggest that microdissector efficacy increases with speed, up to 5000 rpm.