99 research outputs found

    A novel three-dimensional computational method to assess rod contour deformation and to map bony fusion in a lumbopelvic reconstruction after en-bloc sacrectomy.

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    Introduction: En-bloc resection of a primary malignant sacral tumor with wide oncological margins impacts the biomechanics of the spinopelvic complex, deteriorating postoperative function. The closed-loop technique (CLT) for spinopelvic fixation (SPF) uses a single U-shaped rod to restore the spinopelvic biomechanical integrity. The CLT method was designed to provide a non-rigid fixation, however this hypothesis has not been previously tested. Here, we establish a computational method to measure the deformation of the implant and characterize the bony fusion process based on the 6-year follow-up (FU) data. Materials and Methods: Post-operative CT scans were collected of a male patient who underwent total sacrectomy at the age of 42 due to a chordoma. CLT was used to reconstruct the spinopelvic junction. We defined the 3D geometry of the implant construct. Using rigid registration algorithms, a common coordinate system was created for the CLT to measure and visualize the deformation of the construct during the FU. In order to demonstrate the cyclical loading of the construct, the patient underwent gait analysis at the 6th year FU. First, a region of interest (ROI) was selected at the proximal level of the construct, then the deformation was determined during the follow-up period. In order to investigate the fusion process, a single axial slice-based voxel finite element (FE) mesh was created. The Hounsfield values (HU) were determined, then using an empirical linear equation, bone mineral density (BMD) values were assigned for every mesh element, out of 10 color-coded categories (1st category = 0 g/cm3, 10th category 1.12 g/cm3). Results: Significant correlation was found between the number of days postoperatively and deformation in the sagittal plane, resulting in a forward bending tendency of the construct. Volume distributions were determined and visualized over time for the different BMD categories and it was found that the total volume of the elements in the highest BMD category in the first postoperative CT was 0.04 cm3, at the 2nd year, FU was 0.98 cm3, and after 6 years, it was 2.30 cm3. Conclusion: The CLT provides a non-rigid fixation. The quantification of implant deformation and bony fusion may help understate the complex lumbopelvic biomechanics after sacrectomy

    Variability in the Effect of 5-HTTLPR on Depression in a Large European Population: The Role of Age, Symptom Profile, Type and Intensity of Life Stressors.

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    BACKGROUND: Although 5-HTTLPR has been shown to influence the risk of life stress-induced depression in the majority of studies, others have produced contradictory results, possibly due to weak effects and/or sample heterogeneity. METHODS: In the present study we investigated how age, type and intensity of life-stressors modulate the effect of 5-HTTLPR on depression and anxiety in a European population cohort of over 2300 subjects. Recent negative life events (RLE), childhood adversity (CHA), lifetime depression, Brief Symptoms Inventory (BSI) depression and anxiety scores were determined in each subject. Besides traditional statistical analysis we calculated Bayesian effect strength and relevance of 5-HTTLPR genotypes in specified models. RESULTS: The short (s) low expressing allele showed association with increased risk of depression related phenotypes, but all nominally significant effects would turn to non-significant after correction for multiple testing in the traditional analysis. Bayesian effect strength and relevance analysis, however, confirmed the role of 5-HTTLPR. Regarding current (BSI) and lifetime depression 5-HTTLPR-by-RLE interactions were confirmed. Main effect, with other words direct association, was supported with BSI anxiety. With more frequent RLE the prevalence or symptoms of depression increased in ss carriers. Although CHA failed to show an interaction with 5-HTTLPR, in young subjects CHA sensitized towards the depression promoting effect of even mild RLE. Furthermore, the direct association of anxiety with the s allele was driven by young (</=30) individuals. LIMITATIONS: Our study is cross-sectional and applies self-report questionnaires. CONCLUSIONS: Albeit 5-HTTLPR has only weak/moderate effects, the s allele is directly associated with anxiety and modulates development of depression in homogeneous subgroups

    Health related quality of life outcomes following surgery and/or radiation for patients with potentially unstable spinal metastases.

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    Currently there is no prospective pain and health related quality of life (HRQOL) data of patients with potentially unstable spinal metastases who were treated with surgery ± radiation or radiation alone.An international prospective cohort multicenter study of patients with potentially unstable spinal metastases, defined by a SINS score 7 to 12, treated with surgery ± radiation or radiotherapy alone was conducted. HRQOL was evaluated with the numeric rating scale (NRS) pain score, the SOSGOQ2.0, the SF-36, and the EQ-5D at baseline and 6, 12, 26, and 52 weeks after treatment.A total of 136 patients were treated with surgery ± radiotherapy and 84 with radiotherapy alone. At baseline, surgically treated patients were more likely to have mechanical pain, a lytic lesion, a greater median Spinal Instability Neoplastic score, vertebral compression fracture, lower performance status, HRQOL, and pain scores. From baseline to 12 weeks post-treatment, surgically treated patients experienced a 3.0-point decrease in NRS pain score (95% CI -4.1 to -1.9, p.001), and a 12.7-point increase in SOSGOQ2.0 score (95% CI 6.3-19.1, p.001). Patients treated with radiotherapy alone experienced a 1.4-point decrease in the NRS pain score (95% CI -2.9 to 0.0, p=.046) and a 6.2-point increase in SOSGOQ2.0 score (95% CI -2.0 to 14.5, p=.331). Beyond 12 weeks, significant improvements in pain and HRQOL metrics were maintained up to 52-weeks follow-up in the surgical cohort, as compared with no significant changes in the radiotherapy alone cohort.Patients treated with surgery demonstrated clinically and statistically significant improvements in pain and HRQOL up to 1-year postsurgery. Treatment with radiotherapy alone resulted in improved pain scores, but these were not sustained beyond 3 months and HRQOL outcomes demonstrated nonsignificant changes over time. Within the SINS potentially unstable group, distinct clinical profiles were observed in patients treated with surgery or radiotherapy alone

    In Vivo Characterization of the Homing Endonuclease within the polB Gene in the Halophilic Archaeon Haloferax volcanii

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    Inteins are parasitic genetic elements, analogous to introns that excise themselves at the protein level by self-splicing, allowing the formation of functional non-disrupted proteins. Many inteins contain a homing endonuclease (HEN) gene, and rely on its activity for horizontal propagation. In the halophilic archaeon, Haloferax volcanii, the gene encoding DNA polymerase B (polB) contains an intein with an annotated but uncharacterized HEN. Here we examine the activity of the polB HEN in vivo, within its natural archaeal host. We show that this HEN is highly active, and able to insert the intein into both a chromosomal target and an extra-chromosomal plasmid target, by gene conversion. We also demonstrate that the frequency of its incorporation depends on the length of the flanking homologous sequences around the target site, reflecting its dependence on the homologous recombination machinery. Although several evolutionary models predict that the presence of an intein involves a change in the fitness of the host organism, our results show that a strain deleted for the intein sequence shows no significant changes in growth rate compared to the wild type

    Interleukin-6 promoter polymorphism interacts with pain and life stress influencing depression phenotypes

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    Interleukin-6 (IL-6) has emerged as a potent biomarker for depression as its elevated plasma levels in patients with clinical depression have been confirmed by meta-analyses. Increased plasma IL-6 concentration was associated with various psychological stress factors and physical disorders accompanied by pain. Another modulator of the IL-6 level is rs1800795, a promoter polymorphism in the IL-6 gene which is able to influence its expression rate. Therefore, we examined in a Hungarian population sample of 1053 volunteers with European origins if rs1800795 polymorphism can affect depression symptoms measured by Zung Self-rating Depression Scale (ZSDS), and Brief Symptom Inventory (BSI). We also investigated the interactions of the polymorphism with reported painful physical conditions and Recent Negative Life Events (RLE) measured by the List of Life Threatening Experiences. Rs1800795 significantly interacted with both RLE and painful condition on depressive symptoms measured by ZSDS and BSI using different heritability models, while no main effects of the polymorphism were identified. After correction for multiple testing only the rs1800795 x RLE interaction effect (recessive model) remained significant on the BSI score, while both RLE and painful conditions significantly interacted on the ZSDS. In conclusion, the functional IL-6 rs1800795 polymorphism in interaction with various stress factors increases the risk of depression and has a greater impact on symptoms measured by the ZSDS. Thus, IL-6 and other cytokines may be more relevant in the development of somatic symptoms compared to affective signs of depression, delineating a specific genotype-phenotype relationship in this heterogeneous disorder

    Maternal bonding styles in smokers and non-smokers: a comparative study

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    BACKGROUND: Parental bonding has been implicated in smoking behavior, and the quality of maternal bonding (MB) has been associated with poor mental health and substance use. However, little is known about the association of MB and the smoking of the offspring. METHODS: In our study, 129 smokers and 610 non-smoker medical students completed the parental bonding instrument, which measures MB along two dimensions: care and overprotection. Four categories can be created by high and low scores on care and overprotection: optimal parenting (OP; high care/low overprotection); affectionless control (ALC; low care/high overprotection); affectionate constraint (AC; high care/high overprotection), and neglectful parenting (NP; low care/low overprotection). Nicotine dependence was assessed by the Fagerstrom Nicotine Dependence Test, exhaled CO level, and daily cigarette consumption (CPD). RESULTS: Higher CPD was significantly associated with lower overprotection (p = 0.016) and higher care (p = 0.023) scores. The odds for being a smoker were significantly higher in the neglectful maternal bonding style compared to the other rearing styles (p = 0.022). Besides, smokers showed significantly higher care and lower overprotection scores with the Mann-Whitney U-test than non-smokers, although these associations did not remain significant in multiple regression models. CONCLUSION: Our results indicate that focusing on early life relationship between patient and mother can be important in psychotherapeutic interventions for smoking. Registration trials retrospectively registered

    Gene expression analysis indicates CB1 receptor upregulation in the hippocampus and neurotoxic effects in the frontal cortex 3 weeks after single-dose MDMA administration in Dark Agouti rats.

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    BACKGROUND: 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") is a widely used recreational drug known to impair cognitive functions on the long-run. Both hippocampal and frontal cortical regions have well established roles in behavior, memory formation and other cognitive tasks and damage of these regions is associated with altered behavior and cognitive functions, impairments frequently described in heavy MDMA users. The aim of this study was to examine the hippocampus, frontal cortex and dorsal raphe of Dark Agouti rats with gene expression arrays (Illumina RatRef bead arrays) looking for possible mechanisms and new candidates contributing to the effects of a single dose of MDMA (15 mg/kg) 3 weeks earlier. RESULTS: The number of differentially expressed genes in the hippocampus, frontal cortex and the dorsal raphe were 481, 155, and 15, respectively. Gene set enrichment analysis of the microarray data revealed reduced expression of 'memory' and 'cognition', 'dendrite development' and 'regulation of synaptic plasticity' gene sets in the hippocampus, parallel to the upregulation of the CB1 cannabinoid- and Epha4, Epha5, Epha6 ephrin receptors. Downregulated gene sets in the frontal cortex were related to protein synthesis, chromatin organization, transmembrane transport processes, while 'dendrite development', 'regulation of synaptic plasticity' and 'positive regulation of synapse assembly' gene sets were upregulated. Changes in the dorsal raphe region were mild and in most cases not significant. CONCLUSION: The present data raise the possibility of new synapse formation/synaptic reorganization in the frontal cortex three weeks after a single neurotoxic dose of MDMA. In contrast, a prolonged depression of new neurite formation in the hippocampus is suggested by the data, which underlines the particular vulnerability of this brain region after the drug treatment. Finally, our results also suggest the substantial contribution of CB1 receptor and endocannabinoid mediated pathways in the hippocampal impairments. Taken together the present study provides evidence for the participation of new molecular candidates in the long-term effects of MDMA

    The same ELA class II risk factors confer equine insect bite hypersensitivity in two distinct populations

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    Insect bite hypersensitivity (IBH) is a chronic allergic dermatitis common in horses. Affected horses mainly react against antigens present in the saliva from the biting midges, Culicoides ssp, and occasionally black flies, Simulium ssp. Because of this insect dependency, the disease is clearly seasonal and prevalence varies between geographical locations. For two distinct horse breeds, we genotyped four microsatellite markers positioned within the MHC class II region and sequenced the highly polymorphic exons two from DRA and DRB3, respectively. Initially, 94 IBH-affected and 93 unaffected Swedish born Icelandic horses were tested for genetic association. These horses had previously been genotyped on the Illumina Equine SNP50 BeadChip, which made it possible to ensure that our study did not suffer from the effects of stratification. The second population consisted of 106 unaffected and 80 IBH-affected Exmoor ponies. We show that variants in the MHC class II region are associated with disease susceptibility (praw = 2.34 × 10−5), with the same allele (COR112:274) associated in two separate populations. In addition, we combined microsatellite and sequencing data in order to investigate the pattern of homozygosity and show that homozygosity across the entire MHC class II region is associated with a higher risk of developing IBH (p = 0.0013). To our knowledge this is the first time in any atopic dermatitis suffering species, including man, where the same risk allele has been identified in two distinct populations

    Financial difficulties but not other types of recent negative life events show strong interactions with 5-HTTLPR genotype in the development of depressive symptoms

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    Several studies indicate that 5-HTTLPR mediates the effect of childhood adversity in the development of depression, while results are contradictory for recent negative life events. For childhood adversity the interaction with genotype is strongest for sexual abuse, but not for other types of childhood maltreatment; however, possible interactions with specific recent life events have not been investigated separately. The aim of our study was to investigate the effect of four distinct types of recent life events in the development of depressive symptoms in a large community sample. Interaction between different types of recent life events measured by the List of Threatening Experiences and the 5-HTTLPR genotype on current depression measured by the depression subscale and additional items of the Brief Symptom Inventory was investigated in 2588 subjects in Manchester and Budapest. Only a nominal interaction was found between life events overall and 5-HTTLPR on depression, which failed to survive correction for multiple testing. However, subcategorising life events into four categories showed a robust interaction between financial difficulties and the 5-HTTLPR genotype, and a weaker interaction in the case of illness/injury. No interaction effect for the other two life event categories was present. We investigated a general non-representative sample in a cross-sectional approach. Depressive symptoms and life event evaluations were self-reported. The 5-HTTLPR polymorphism showed a differential interaction pattern with different types of recent life events, with the strongest interaction effects of financial difficulties on depressive symptoms. This specificity of interaction with only particular types of life events may help to explain previous contradictory findings
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