Kyphoplasty patient-centered outcomes via questionnaire

Background

To assess patient centered outcomes among adults with compression fractures treated by kyphoplasty.

Methods

A 3-question survey was administered via telephone to patients who had a kyphoplasty procedure performed from 2008-2011.

Results

One hundred fifty-one patients completed the telephone satisfaction survey. Of these, 95.4% of respondents said the procedure was tolerable, 82.8% had full or partial pain relief and 66.2% would have the procedure again.

Conclusions

Large randomized and observational evidence support the use of kyphoplasty in osteoporotic and malignant compression fractures. Based on our survey, patients believe kyphoplasty is a tolerable procedure that produces full or partial pain relief and would undergo the procedure again if needed.

An integrative in silico system for predicting dysregulated genes in the human epileptic focus: Application to SLC transporters

OBJECTIVE

Many different gene families are currently being investigated for their potential role in epilepsy and in the response to antiepileptic drugs. A common research challenge is identifying the members of a gene family that are most significantly dysregulated within the human epileptic focus, before taking them forward for resource-intensive functional studies. Published data about transcriptomic changes within the human epileptic focus remains incomplete. A need exists for an accurate in silico system for the prediction of dysregulated genes within the epileptic focus. We present such a bioinformatic system. We demonstrate the validity of our approach by applying it to the solute carrier (SLC) gene family. There are >400 known SLCs. SLCs have never been systematically studied in epilepsy.

METHODS

Using our in silico system, we predicted the SLCs likely to be dysregulated in the epileptic focus. We validated our in silico predictions by identifying ex vivo the SLCs dysregulated in epileptic foci, and determining the overlap between our in silico and ex vivo results. For the ex vivo analysis, we used a custom oligonucleotide microarray containing exon probes for all known SLCs to analyze 24 hippocampal samples obtained from surgery for pharmacoresistant mesial temporal lobe epilepsy and 24 hippocampal samples from normal postmortem controls.

RESULTS

There was a highly significant (p < 9.99 × 10(-7) ) overlap between the genes identified by our in silico and ex vivo strategies. The SLCs identified were either metal ion exchangers or neurotransmitter transporters, which are likely to play a part in epilepsy by influencing neuronal excitability.

SIGNIFICANCE

The identified SLCs are most likely to mediate pharmacoresistance in epilepsy by enhancing the intrinsic severity of epilepsy, but further functional work will be needed to fully evaluate their role. Our successful in silico strategy can be adapted in order to prioritize genes relevant to epilepsy from other gene families.

Spatio-Chromatic Information Content of Natural Scenes

A common assumption in the study of the relationship between human vision and the visual environment is that human vision has developed in order to encode the incident information in an optimal manner. Such arguments have been used to support the 1/f dependence of scene content as a function of spatial frequency. In keeping with this assumption, we ask whether there are any important differences between the luminance and (r/g) chrominance Fourier spectra of natural scenes, the simple expectation being that the chrominance spectrum should be relatively richer in low spatial frequencies than the luminance spectrum, to correspond with the different shape of luminance and chrominance contrast sensitivity functions.

We analysed a data set of 29 images of natural scenes (predominantly of vegetation at different distances) which were obtained with a hyper-spectral camera (measuring the scene through a set of 31 wavelength bands in the range 400 – 700 nm). The images were transformed to the three Smith — Pokorny cone fundamentals, and further transformed into ‘luminance’ (r+g) and ‘chrominance’ (r-g) images, with various assumptions being made about the relative weighting of the r and g components, and the form of the chrominance response. We then analysed the Fourier spectra of these images using logarithmic intervals in spatial frequency space. This allowed a determination of the total energy within each Fourier band for each of the luminance and chrominance representations.

The results strongly indicate that, for the set of scenes studied here, there was no evidence of a predominance of low-spatial-frequency chrominance information. Two classes of explanation are possible: (a) that raw Fourier content may not be the main organising principle determining visual encoding of colour, and/or (b) that our scenes were atypical of what may have driven visual evolution. We present arguments in favour of both of these propositions.

Aneuploidy shortens replicative lifespan in Saccharomyces cerevisiae

Aneuploidy and aging are correlated; however, a causal link between these two phenomena has remained elusive. Here, we show that yeast disomic for a single native yeast chromosome generally have a decreased replicative lifespan. In addition, the extent of this lifespan deficit correlates with the size of the extra chromosome. We identified a mutation in BUL1 that rescues both the lifespan deficit and a protein trafficking defect in yeast disomic for chromosome 5. Bul1 is an E4 ubiquitin ligase adaptor involved in a protein quality control pathway that targets membrane proteins for endocytosis and destruction in the lysosomal vacuole, thereby maintaining protein homeostasis. Concurrent suppression of the aging and trafficking phenotypes suggests that disrupted membrane protein homeostasis in aneuploid yeast may contribute to their accelerated aging. The data reported here demonstrate that aneuploidy can impair protein homeostasis, shorten lifespan, and may contribute to age-associated phenotypes.

A Comprehensive Analysis of Replicative Lifespan in 4,698 Single-Gene Deletion Strains Uncovers Conserved Mechanisms of Aging

Many genes that affect replicative lifespan (RLS) in the budding yeast Saccharomyces cerevisiae also affect aging in other organisms such as C. elegans and M. musculus. We performed a systematic analysis of yeast RLS in a set of 4,698 viable single-gene deletion strains. Multiple functional gene clusters were identified, and full genome-to-genome comparison demonstrated a significant conservation in longevity pathways between yeast and C. elegans. Among the mechanisms of aging identified, deletion of tRNA exporter LOS1 robustly extended lifespan. Dietary restriction (DR) and inhibition of mechanistic Target of Rapamycin (mTOR) exclude Los1 from the nucleus in a Rad53-dependent manner. Moreover, lifespan extension from deletion of LOS1 is nonadditive with DR or mTOR inhibition, and results in Gcn4 transcription factor activation. Thus, the DNA damage response and mTOR converge on Los1-mediated nuclear tRNA export to regulate Gcn4 activity and aging.

An international study of the quality of national-level guidelines on driving with medical illness

BACKGROUND

Medical illnesses are associated with a modest increase in crash risk, although many individuals with acute or chronic conditions may remain safe to drive, or pose only temporary risks. Despite the extensive use of national guidelines about driving with medical illness, the quality of these guidelines has not been formally appraised.

AIM

To systematically evaluate the quality of selected national guidelines about driving with medical illness.

DESIGN

A literature search of bibliographic databases and Internet resources was conducted to identify the guidelines, each of which was formally appraised.

METHODS

Eighteen physicians or researchers from Canada, Australia, Ireland, USA and UK appraised nine national guidelines, applying the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument.

RESULTS

Relative strengths were found in AGREE II scores for the domains of scope and purpose, stakeholder involvement and clarity of presentation. However, all guidelines were given low ratings on rigour of development, applicability and documentation of editorial independence. Overall quality ratings ranged from 2.25 to 5.00 out of 7.00, with modifications recommended for 7 of the guidelines. Intra-class coefficients demonstrated fair to excellent appraiser agreement (0.57-0.79).

CONCLUSIONS

This study represents the first systematic evaluation of national-level guidelines for determining medical fitness to drive. There is substantive variability in the quality of these guidelines, and rigour of development was a relative weakness. There is a need for rigorous, empirically derived guidance for physicians and licensing authorities when assessing driving in the medically ill.

Preventing proximal junctional failure in long segmental instrumented cases of adult degenerative scoliosis using a multilevel stabilization screw technique

BACKGROUND

The authors sought to demonstrate the safety and effectiveness of the multilevel stabilization screw (MLSS) technique in decreasing the incidence of proximal junctional failure in long segmental instrumented fusions for adult degenerative scoliosis.

METHODS

Institutional review board approval was obtained and all patients with adult spinal deformity who underwent the MLSS technique were analyzed. A neuro-radiologist and spine-focused neurosurgeon not involved with the surgical treatment performed radiographic analysis. Proximal junctional angle was defined as the caudal endplate of the upper instrumented vertebra (UIV) to the cephalad endplate of two supradjacent vertebrae above the UIV. The UIV is defined as the most cephalad vertebra completed captured by the instrumentation. Abnormal proximal junctional kyphosis (PJK) was defined as proximal junctional sagittal Cobb angle >10 degrees and proximal junction sagittal Cobb angle at least 10 degrees greater than the preoperative measurement. The presence of both is criteria necessary to be considered abnormal.

RESULTS

Twenty patients with degenerative scoliosis underwent the MLSS technique with the upper-instrumented vertebrae in the proximal thoracic spine. Fifteen patients met inclusion criteria with greater than 12 months radiographic and clinical follow up. Three patients were excluded due to lack of follow up imaging and two patients were excluded due to the inability to measure the UIV. Age range was 44-84 years with a mean of 66. Eleven of the 15 patients were over the age of 60 at the time of surgery. The male-to-female ratio was 4:11. Body mass index (BMI) range was 24-44 with a mean of 31.5 units. The follow up period ranged from 14 to 58 months with an average follow up of 30 months. The mean change in Cobb angle at the proximal junction was 4.00 degrees with a range from -0.92 to 9.13 degrees. There were no fractures or instrumentation failures at or near the proximal junction. There was no revision surgeries performed for proximal junctional failure. Retrospective clinical questionnaires revealed that surgical expectations were met in 15 of 19 patients surveyed, 79%. One patient was not reachable for a postoperative phone interview. In patients who were not satisfied with their overall experience, the change in Cobb angle ranged from -0.92 to 9.13 degrees with an average change of 3.90 degrees. Whereas patients reporting an overall positive experience had a change in Cobb angle range from -0.12 to 8.07 degrees with an average change of 4.05 degrees.

CONCLUSION

PJK and failure are well-recognized suboptimal outcomes of long-segmental fusions of the thoracolumbar spine that can lead to significant neurological morbidity and costly revision surgeries. With no known proximal junction failures to date, the MLSS technique has shown promising results in preventing adverse proximal junctional conditions and can be safely performed under fluoroscopy guidance. Future direction includes a comparative study establishing the relative risk of developing PJK with this novel technique versus a traditional long-segmental thoracolumbar fusion.

Folate Augmentation of Treatment--Evaluation for Depression (FolATED): randomised trial and economic evaluation

BACKGROUND

Folate deficiency is associated with depression. Despite the biological plausibility of a causal link, the evidence that adding folate enhances antidepressant treatment is weak.

OBJECTIVES

(1) Estimate the clinical effectiveness and cost-effectiveness of folic acid as adjunct to antidepressant medication (ADM). (2) Explore whether baseline folate and homocysteine predict response to treatment. (3) Investigate whether response to treatment depends on genetic polymorphisms related to folate metabolism.

DESIGN

FolATED (Folate Augmentation of Treatment - Evaluation for Depression) was a double-blind and placebo-controlled, but otherwise pragmatic, randomised trial including cost-utility analysis. To yield 80% power of detecting standardised difference on the Beck Depression Inventory version 2 (BDI-II) of 0.3 between groups (a 'small' effect), FolATED trialists sought to analyse 358 participants. To allow for an estimated loss of 21% of participants over three time points, we planned to randomise 453.

SETTINGS

Clinical - Three centres in Wales - North East Wales, North West Wales and Swansea. Trial management - North Wales Organisation for Randomised Trials in Health in Bangor University. Biochemical analysis - University Hospital of Wales, Cardiff. Genetic analysis - University of Liverpool.

PARTICIPANTS

Four hundred and seventy-five adult patients presenting to primary or secondary care with confirmed moderate to severe depression for which they were taking or about to start ADM, and able to consent and complete assessments, but not (1) folate deficient, vitamin B12 deficient, or taking folic acid or anticonvulsants; (2) misusing drugs or alcohol, or suffering from psychosis, bipolar disorder, malignancy or other unstable or terminal illness; (3) (planning to become) pregnant; or (4) participating in other clinical research.

INTERVENTIONS

Once a day for 12 weeks experimental participants added 5 mg of folic acid to their ADM, and control participants added an indistinguishable placebo. All participants followed pragmatic management plans initiated by a trial psychiatrist and maintained by their general medical practitioners.

MAIN OUTCOME MEASURES

Assessed at baseline, and 4, 12 and 25 weeks thereafter, and analysed by 'area under curve' (main); by analysis of covariance at each time point (secondary); and by multi-level repeated measures (sensitivity analysis): Mental health - BDI-II (primary), Clinical Global Impression (CGI), Montgomery-Åsberg Depression Rating Scale (MADRS), UKU side effects scale, and Mini International Neuropsychiatric Interview (MINI) suicidality subscale; General health - UK 12-item Short Form Health Survey (SF-12), European Quality of Life scale - 5 Dimensions (EQ-5D); Biochemistry - serum folate, B12, homocysteine; Adherence - Morisky Questionnaire; Economics - resource use.

RESULTS

Folic acid did not significantly improve any of these measures. For example it gained a mean of just 2.9 quality-adjusted life-days [95% confidence interval (CI) from -12.7 to 7.0 days] and saved a mean of just £48 (95% CI from -£292 to £389). In contrast it significantly reduced mental health scores on the SF-12 by 3.0% (95% CI from -5.2% to -0.8%).

CONCLUSIONS

The FolATED trial generated no evidence that folic acid was clinically effective or cost-effective in augmenting ADM. This negative finding is consistent with improving understanding of the one-carbon folate pathway suggesting that methylfolate is a better candidate for augmenting ADM. Hence the findings of FolATED undermine treatment guidelines that advocate folic acid for treating depression, and suggest future trials of methylfolate to augment ADM.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN37558856.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 18, No. 48. See the HTA programme website for further project information.

Molecular mechanisms underlying genotype-dependent responses to dietary restriction

Dietary restriction (DR) increases lifespan and attenuates age-related phenotypes in many organisms; however, the effect of DR on longevity of individuals in genetically heterogeneous populations is not well characterized. Here, we describe a large-scale effort to define molecular mechanisms that underlie genotype-specific responses to DR. The effect of DR on lifespan was determined for 166 single gene deletion strains in Saccharomyces cerevisiae. Resulting changes in mean lifespan ranged from a reduction of 79% to an increase of 103%. Vacuolar pH homeostasis, superoxide dismutase activity, and mitochondrial proteostasis were found to be strong determinants of the response to DR. Proteomic analysis of cells deficient in prohibitins revealed induction of a mitochondrial unfolded protein response (mtUPR), which has not previously been described in yeast. Mitochondrial proteotoxic stress in prohibitin mutants was suppressed by DR via reduced cytoplasmic mRNA translation. A similar relationship between prohibitins, the mtUPR, and longevity was also observed in Caenorhabditis elegans. These observations define conserved molecular processes that underlie genotype-dependent effects of DR that may be important modulators of DR in higher organisms.

Dimethyl fumarate stimulates cyclic AMP production and suppresses production of pro-inflammatory mediators in immune cells (P5143)

Multiple Sclerosis (MS) is a disease of the central nervous system that is characterized by chronic inflammation, demyelination, axonal damage and loss of oligodendrocytes. Current FDA approved therapies are only partially effective, have side-effects and are costly. Thus, there is a need for development of novel treatment alternatives for MS. Of interest is the investigational drug BG-12, also known as dimethyl fumarate (DMF). A phase III clinical trial showed that treatment with BG-12 reduced the annual relapse rate by 53% and decreased disability by 38%. Additionally, BG-12 reduced the number of gadolinium-enhancing lesions by 90%. However, the mechanisms of action of BG-12 are not fully understood. BG-12 is an activator of the nuclear factor (erythroid-derived 2)-like 2 (NRF2) transcriptional pathway. To determine if BG-12 is able to activate other signaling cascades, we treated human peripheral blood mononuclear cells with DMF. We discovered that DMF stimulates cAMP production by approximately 3.5 after 1 minute treatment in vitro. DMF also suppresses the production of interleukin (IL)-2, IL-17, regulated and normal T cell expressed and secreted (RANTES) and tumor necrosis factor (TNF)-α in these cells. Furthermore, inhibitor studies indicate that adenylyl cyclases mediate DMF induced cAMP production. These novel findings suggest that DMF may inhibit immune cell function via the cAMP signaling pathway and has implications for MS therapy.

Nucleotide-binding and oligomerization domain 2 (NOD2) knock-in mice carrying a mutation associated with Blau syndrome show reduced amounts of NOD2 protein and decreased muramyl dipeptide (MDP)-induced inflammatory responses (P1254)

Blau syndrome is an autosomal dominant disorder caused by mutations in NOD2 and characterized by arthritis, dermatitis and uveitis. NOD2 binds MDP and activates NF-kB and MAPK signaling cascades. Prior in vitro studies reported that NOD2 containing Blau mutations caused enhanced activation of NF-kB, suggesting a gain of function in mutated NOD2 caused Blau syndrome. We tested this hypothesis in vivo by creating a knock-in mouse where a point mutation resulted in a change of arginine [R] to glutamine [Q] at position 314 (R314Q) of NOD2 (position 314 in mice corresponds to 334 in humans). R314Q heterozygous (+/m) and homozygous (m/m) mice did not spontaneously develop arthritis or dermatitis. Bone marrow derived macrophages (BMDM) from R314Q mice showed a reduction in NOD2 protein levels compared to wild type (WT) mice despite comparable amounts of NOD2 mRNA. MDP treatment of BMDM showed reduced activation of NF-kB and p38 MAPK in +/m and m/m compared to WT mice that correlated with the copy number of mutated NOD2, with the greatest reduction in m/m mice. In response to ip MDP, reduced levels of IL-6 and KC were detected in the serum of +/m and m/m mice, also in manner correlating with the copy number of the mutation. These data indicate that R314Q-NOD2 mice do not demonstrate a gain of function of the NOD2 pathway. Rather, R314Q causes a deficiency of NOD2 and raises the possibility that Blau syndrome may fall within the spectrum of an immunodeficiency disease.