High-throughput DNA methylation analysis in anorexia nervosa confirms TNXB hypermethylation

OBJECTIVES

Patients with anorexia nervosa (AN) are ideally suited to identify differentially methylated genes in response to starvation.

METHODS

We examined high-throughput DNA methylation derived from whole blood of 47 females with AN, 47 lean females without AN and 100 population-based females to compare AN with both controls. To account for different cell type compositions, we applied two reference-free methods (FastLMM-EWASher, RefFreeEWAS) and searched for consensus CpG sites identified by both methods. We used a validation sample of five monozygotic AN-discordant twin pairs.

RESULTS

Fifty-one consensus sites were identified in AN vs. lean and 81 in AN vs. population-based comparisons. These sites have not been reported in AN methylation analyses, but for the latter comparison 54/81 sites showed directionally consistent differential methylation effects in the AN-discordant twins. For a single nucleotide polymorphism rs923768 in CSGALNACT1 a nearby site was nominally associated with AN. At the gene level, we confirmed hypermethylated sites at TNXB. We found support for a locus at NR1H3 in the AN vs. lean control comparison, but the methylation direction was opposite to the one previously reported.

CONCLUSIONS

We confirm genes like TNXB previously described to comprise differentially methylated sites, and highlight further sites that might be specifically involved in AN starvation processes.

Long-Term Results From Tonsillectomy in Adults

BACKGROUND

Tonsillectomy is performed more than 400 000 times in the European Union each year, making it one of the most common operations. Nonetheless, there have been only a few long-term studies of quality of life after tonsillectomy.

METHODS

In 2004, data on the quality of life after tonsillectomy were obtained from adult German-speaking tonsillectomy patients by means of the Glasgow Benefit Inventory and a questionnaire specifically designed for that study. The present study concerns the further followup of these patients, sometimes many years later. 114 patients with recurrent tonsillitis were included in this descriptive study.

RESULTS

Of the 114 patients, 97 (85%) provided further data at 14 months, and 71 (62%) at ca. 7 years. The Glasgow Benefit Inventory revealed postoperative improvement of quality of life at 14 months and at 7 years, with median values of 16.67 points (quartile 11.11/25) and 13.89 points (quartile 8.33/25) (p=0.168). The mean number of annual episodes of sore throat fell from 10 preoperatively to 2 postoperatively (p=0.0001). The number of visits to the doctor, the intake of analgesic drugs and antibiotics, and the number of medical absences from work also declined significantly over the period of observation.

CONCLUSION

Tonsillectomy was associated with a longlasting improvement of health and quality of life, and with lower utilization of medical resources. The 62% response rate at 7 years leaves the question open whether patients with a favorable postoperative course may have been more likely than others to participate in the study.

Determinants of decreasing major amputation rates in Germany

BACKGROUND

We analysed a potential association between the decrease in major amputations in Germany and the number of doctors, prescribed podologic foot care (PFC) and antidiabetic drugs, and performed percutaneous endoluminal angioplasties (PTA).

PATIENTS AND METHODS

Data of all lower limb major amputations between 2007 and 2011, the cases hospitalised with an additional diagnosis of diabetes mellitus, and the numbers of PTAs, and the number of doctors in private practices and in hospitals were obtained from the Federal Statistical Office. Furthermore, the number of PFC treatments and prescribed antidiabetics for each of the five years were derived from the federal report of the statutory health insurance.

RESULTS

Within the 5 year time period, major amputations decreased by 19.0%, from 17,846 in 2007 to 14,463 in 2011. There is an inverse relation between the number of major amputations and the increasing number of prescribed PFC, of doctors working in hospital and of below-the-knee PTA in the multiple Poisson regression analysis. The number of prescribed antidiabetics and that of all PTA showed a positive relation. In the multiple linear regression analysis with the dependent variable ratio of amputations and the cases hospitalised with an additional diagnosis of diabetes mellitus, only numbers of prescribed PFC and below-the-knee PTA still showed an inverse relation that reached a level of significance.

CONCLUSIONS

While substantial improvements in patients care by doctors, endovascular interventions, prescriptions of PFC and antidiabetic drugs are under discussion to reduce major amputation rates, in this approach including comprehensive data from Germany, only prescriptions of PFC and the number of below-the-knee PTA had an independent and significant impact on the reduction of major amputations. It has to be pointed out that such a statistical association does not prove any causality.

Neoadjuvant, anthracycline-free chemotherapy with carboplatin and docetaxel in triple-negative, early-stage breast cancer: a multicentric analysis of rates of pathologic complete response and survival

INTRODUCTION

Triple-negative breast cancer (TNBC) has the highest mortality rates of all subtypes. Anthracycline and taxane regimens yield unsatisfactorily low rates of pathologic complete response (pCR) and are often not feasible in cardiac comorbidity. This study seeks to increase pCR and survival by introducing platin agents.

PATIENTS AND METHODS

In this multicentric, open-label study with six cycles of docetaxel (75 mg/m(2)) and carboplatin AUC 6 q3w, patients were unwilling or unsuitable for anthracycline-based regimens. Primary endpoint was pCR (ypT0/ypTis ypN0) and survival.

RESULTS

pCR rate was 50%. After 2 and 5 years, overall survival (OS) was 96.7 and 89.7%, disease-free-survival (DFS) 96.7 and 85.7%, DDFS 96.7 and 89.6%. Grade 3/4 toxicities were rare. Ninety-three per cent of patients completed six cycles. No toxicity-related treatment discontinuation or febrile neutropaenia was recorded.

CONCLUSION

This regimen is highly effective and feasible in TNBC and may be combined with anthracyclines.

Abstract P2-13-01: Stage-related risk categorization and influence of free margins on survival in triple negative early breast cancer - a population-based study of 2037 TNBC patients with adjuvant chemotherapy

Introduction: Triple negative breast cancer (TNBC) represents 10-20% of all breast cancer entities [1][2] and has a known aggressive behavior and poor outcome. Patients treated in the setting of randomized clinical trials often do not represent actual treatment characteristics in real-life scenarios. To determine the stage-related survival and effect of surgical performance in TNBC with current multimodal treatment, we set out to analyze data of a large population-based registry of primary breast cancers which covering >50% of all breast cancer cases in Germany.

Patients and methods: We analyzed data from a prospectively collected cancer registry of >200 certified breast units of the West-German Breast Center (WBC) in Germany from 2009-2011. From a cohort of 39570 primary breast cancer patients treated in this period, 12759 underwent adjuvant systemic therapy, out of which 2037 were TNBC cases with adjuvant chemotherapy. Inclusion criteria were triple negative breast cancers (Her2-new1+/2+ (Fish negative) and estrogen receptor (ER) and progesterone receptor (PR) <10%) and adjuvant chemotherapy, unilateral and non-metastasized breast cancer. Only those patients were included who have been followed-up within the first 3 years. Exclusion criteria were neoadjuvant chemotherapy, bilateral breast cancer and metastatic disease.

The use of first, second and third generation chemotherapy was analyzed as well as the effect of clear/unclear resection margins and its impact on survival data.

Results:

2037 patients were eligible for this study. Overall survival rates were as follows: T1 a and T1b 100 %, T1c 90,7 %, T2 90,9 %, T3 68,1 % and T4 64,3 %. No statistical differences were detected in between stages T1 and T2, and also not in between T3 and T4. Combining T1/T2 and T3/T4 and performing group-wise comparisons, differences for combined stages were highly statistically significant (3,9 x E-09). Inflammatory TNBC was prognostically worst with a survival-rate of 33,3 % at 24-months. (p<0,001)

Unclear resection-margins versus clear margins in TNBC exerted a negative impact on DFS (87 vs. 73 %; p=0,00002) and DDFS (p=0,0004). Age was an independent risk factor for survival with a cut-off at 35 years.(p=0,044)

Third-generation chemotherapies (anthracycline+taxanes) were associated with a significant improved overall-survival at 24-months compared to first generation chemotherapies (non-anthracycline, non-taxane) (95 % vs. 87 %; p=0,0029)

Conclusion: Standard 3rd generation (anthracycline- and taxane-containing) chemotherapy and optimal surgical performance with clear margins is vital for patients with early, triple-negative breast cancer (TNBC). Within T1 and T2 stages, no stage-related deterioration of prognosis was detected, however these stages were markedly different from stages T3/T4, declining from 90-100% to 64-68 %.

This analysis of a large database of a population-based study demonstrates that tumor size, margins and guideline-adapted chemotherapy matter in triple-negative, early breast cancer.

[1] Schwentner et al. 2013

[2] Elsawaf et al. 2013.

Citation Format: Peter Kern, Gunter von Minckwitz, Carolin Pütter, Annika Flach, Sofia Pavlidou, Rainer Kimmig, Mahdi Rezai. Stage-related risk categorization and influence of free margins on survival in triple negative early breast cancer - a population-based study of 2037 TNBC patients with adjuvant chemotherapy [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-13-01.

Severe blunt muscle trauma in rats: only marginal hypoxia in the injured area

Background

After severe muscle trauma, hypoxia due to microvascular perfusion failure is generally believed to further increase local injury and to impair healing. However, detailed analysis of hypoxia at the cellular level is missing. Therefore, in the present work, spectroscopic measurements of microvascular blood flow and O₂ supply were combined with immunological detection of hypoxic cells to estimate O₂ conditions within the injured muscle area.

Materials and Methods

Severe blunt muscle trauma was induced in the right Musculus gastrocnemius of male Wistar rats by a standardized “weight-drop” device. Microvascular blood flow, relative hemoglobin amount, and hemoglobin O₂ saturation were determined by laser Doppler and white-light spectroscopy. Hypoxic cells were detected by histologic evaluation of covalent binding of pimonidazole and expression of HIF-1α.

Results

Directly after trauma and until the end of experiment (480 minutes), microvascular blood flow and relative hemoglobin amount were clearly increased. In contrast to blood flow and relative hemoglobin amount, there was no immediate but a delayed increase of microvascular hemoglobin O₂ saturation. Pimonidazole immunostaining revealed a hypoxic fraction (percentage area of pimonidazole-labelled muscle cells within the injured area) between 8 to 3%. There was almost no HIF-1α expression detectable in the muscle cells under each condition studied.

Conclusions

In the early phase (up to 8 hours) after severe blunt muscle trauma, the overall microvascular perfusion of the injured area and thus its O₂ supply is clearly increased. This increased O₂ supply is obviously sufficient to ensure normoxic (or even hyperoxic) conditions in the vast majority of the cells.

Genome-wide analysis of rare copy number variations reveals PARK2 as a candidate gene for attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a common, highly heritable neurodevelopmental disorder. Genetic loci have not yet been identified by genome-wide association studies. Rare copy number variations (CNVs), such as chromosomal deletions or duplications, have been implicated in ADHD and other neurodevelopmental disorders. To identify rare (frequency ≤1%) CNVs that increase the risk of ADHD, we performed a whole-genome CNV analysis based on 489 young ADHD patients and 1285 adult population-based controls and identified one significantly associated CNV region. In tests for a global burden of large (>500 kb) rare CNVs, we observed a nonsignificant (P=0.271) 1.126-fold enriched rate of subjects carrying at least one such CNV in the group of ADHD cases. Locus-specific tests of association were used to assess if there were more rare CNVs in cases compared with controls. Detected CNVs, which were significantly enriched in the ADHD group, were validated by quantitative (q)PCR. Findings were replicated in an independent sample of 386 young patients with ADHD and 781 young population-based healthy controls. We identified rare CNVs within the parkinson protein 2 gene (PARK2) with a significantly higher prevalence in ADHD patients than in controls (P=2.8 × 10(-4) after empirical correction for genome-wide testing). In total, the PARK2 locus (chr 6: 162 659 756-162 767 019) harboured three deletions and nine duplications in the ADHD patients and two deletions and two duplications in the controls. By qPCR analysis, we validated 11 of the 12 CNVs in ADHD patients (P=1.2 × 10(-3) after empirical correction for genome-wide testing). In the replication sample, CNVs at the PARK2 locus were found in four additional ADHD patients and one additional control (P=4.3 × 10(-2)). Our results suggest that copy number variants at the PARK2 locus contribute to the genetic susceptibility of ADHD. Mutations and CNVs in PARK2 are known to be associated with Parkinson disease.

Impact of repetitive exposure to strong static magnetic fields on pregnancy and embryonic development of mice

PURPOSE

To evaluate possible risks of strong static magnetic fields for embryo implantation, gestation, organogenesis, and embryonic development.

MATERIALS AND METHODS

Pregnant mice were exposed for 75 minutes daily during the entire course of pregnancy at the bore entrance, representing the position of medical staff, and at the isocenter, representing the position of patients, of a 1.5 T and a 7 T human MRI scanner.

RESULTS

No effect of static magnetic field strength was observed with regard to pregnancy rate, duration of pregnancy, litter size, still births, malformations, sex distribution, or postpartum death of offspring. During the first 8 weeks postnatal, mice exposed in utero to a magnetic field strength of 1.5 T or stronger showed a slight delay in weight gain and in time to eye opening compared to controls.

CONCLUSION

Daily exposure to strong magnetic fields during pregnancy had no deleterious effect on offspring; however, a developmental retardation could be observed postnatally with regard to weight gain and eye opening.

Meta-analysis of gene-level associations for rare variants based on single-variant statistics

Meta-analysis of genome-wide association studies (GWASs) has led to the discoveries of many common variants associated with complex human diseases. There is a growing recognition that identifying "causal" rare variants also requires large-scale meta-analysis. The fact that association tests with rare variants are performed at the gene level rather than at the variant level poses unprecedented challenges in the meta-analysis. First, different studies may adopt different gene-level tests, so the results are not compatible. Second, gene-level tests require multivariate statistics (i.e., components of the test statistic and their covariance matrix), which are difficult to obtain. To overcome these challenges, we propose to perform gene-level tests for rare variants by combining the results of single-variant analysis (i.e., p values of association tests and effect estimates) from participating studies. This simple strategy is possible because of an insight that multivariate statistics can be recovered from single-variant statistics, together with the correlation matrix of the single-variant test statistics, which can be estimated from one of the participating studies or from a publicly available database. We show both theoretically and numerically that the proposed meta-analysis approach provides accurate control of the type I error and is as powerful as joint analysis of individual participant data. This approach accommodates any disease phenotype and any study design and produces all commonly used gene-level tests. An application to the GWAS summary results of the Genetic Investigation of ANthropometric Traits (GIANT) consortium reveals rare and low-frequency variants associated with human height. The relevant software is freely available.

Relationship between carotid intima-media thickness and metabolic syndrome in adolescents

OBJECTIVE

To test the hypothesis that metabolic syndrome (MetS) is more predictive of carotid intima-media thickness (IMT) than the sum of the individual components of MetS.

STUDY DESIGN

We analyzed the relationships between 2 definitions of the MetS and IMT in 461 overweight adolescents aged 10-18 years (median body mass index, 28.6 kg/m(2)). We used regression models and receiver operating characteristics (ROCs) for increased IMT (defined as ≥0.7 mm).

RESULTS

The prevalence of MetS was 15.0% and 26.9% according to the 2 definitions applied. At the group level, quantitative IMT was associated with body mass index, blood pressure, glucose levels at 2 hours in an oral glucose tolerance test, and with each of the MetS components (all P < .05). At an individual level, using the MetS definitions alone as a diagnostic test for the presence of increased IMT (area under the ROC curve, 0.60-0.66) was inferior when compared with the sum of all individual components (area under the ROC curve, 0.65-0.85). Adding the presence or absence of MetS to the components did not improve the accuracy.

CONCLUSION

Overweight adolescents with MetS demonstrated increased IMT values compared with overweight adolescents without MetS. The best model for diagnosing increased IMT was the sum of the quantitative components of MetS. The use of dichotomized variables reduced the diagnostic accuracy. Thus, in clinical practice, treatment of overweight adolescents should be based on weighing cardiovascular risk factors themselves, rather than on the dichotomous variable MetS.

Common obesity risk alleles in childhood attention-deficit/hyperactivity disorder

Children with attention-deficit/hyperactivity disorder (ADHD) have a higher rate of obesity than children without ADHD. Obesity risk alleles may overlap with those relevant for ADHD. We examined whether risk alleles for an increased body mass index (BMI) are associated with ADHD and related quantitative traits (inattention and hyperactivity/impulsivity). We screened 32 obesity risk alleles of single nucleotide polymorphisms (SNPs) in a genome-wide association study (GWAS) for ADHD based on 495 patients and 1,300 population-based controls and performed in silico analyses of the SNPs in an ADHD meta-analysis comprising 2,064 trios, 896 independent cases, and 2,455 controls. In the German sample rs206936 in the NUDT3 gene (nudix; nucleoside diphosphate linked moiety X-type motif 3) was associated with ADHD risk (OR: 1.39; P = 3.4 × 10(-4) ; Pcorr  = 0.01). In the meta-analysis data we found rs6497416 in the intronic region of the GPRC5B gene (G protein-coupled receptor, family C, group 5, member B; P = 7.2 × 10(-4) ; Pcorr  = 0.02) as a risk allele for ADHD. GPRC5B belongs to the metabotropic glutamate receptor family, which has been implicated in the etiology of ADHD. In the German sample rs206936 (NUDT3) and rs10938397 in the glucosamine-6-phosphate deaminase 2 gene (GNPDA2) were associated with inattention, whereas markers in the mitogen-activated protein kinase 5 gene (MAP2K5) and in the cell adhesion molecule 2 gene (CADM2) were associated with hyperactivity. In the meta-analysis data, MAP2K5 was associated with inattention, GPRC5B with hyperactivity/impulsivity and inattention and CADM2 with hyperactivity/impulsivity. Our results justify further research on the elucidation of the common genetic background of ADHD and obesity.

Genome-wide meta-analysis identifies 11 new loci for anthropometric traits and provides insights into genetic architecture

Approaches exploiting trait distribution extremes may be used to identify loci associated with common traits, but it is unknown whether these loci are generalizable to the broader population. In a genome-wide search for loci associated with the upper versus the lower 5th percentiles of body mass index, height and waist-to-hip ratio, as well as clinical classes of obesity, including up to 263,407 individuals of European ancestry, we identified 4 new loci (IGFBP4, H6PD, RSRC1 and PPP2R2A) influencing height detected in the distribution tails and 7 new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3 and ZZZ3) for clinical classes of obesity. Further, we find a large overlap in genetic structure and the distribution of variants between traits based on extremes and the general population and little etiological heterogeneity between obesity subgroups.

Analyses of non-synonymous obesity risk alleles in SH2B1 (rs7498665) and APOB48R (rs180743) in obese children and adolescents undergoing a 1-year lifestyle intervention

Association of obesity risk alleles of single nucleotide polymorphisms (SNPs) near or in the SH2B adaptor protein 1 gene (SH2B1) and increased body mass index (BMI) has been often described. A gene in close proximity, apolipoprotein B48 receptor gene (APOB48R), is tagged by the same SNP(s).We analyzed 454 overweight and obese children and adolescents (10.8±2.6 years, BMI-SDS 2.4±0.5; 55% girls) who completed a 1-year lifestyle intervention ('Obeldicks' program). Carriers of obesity risk alleles of non-synonymous SNPs in SH2B1 (rs7498665, Thr484Ala) or APOB48R (rs180743, Pro419Ala), as genotyped by TaqMan, were analysed for changes in anthropometrics (body-mass index (BMI), and standardized BMI (BMI-SDS)), blood pressure (systolic and diastolic) and plasma parameters (total cholesterol, LDL-cholesterol, HDL-cholesterol, triacylglycerides, glucose, insulin, and HOMA).We observed no evidence for an association of the obesity risk alleles to alterations in any of the analyzed phenotypes. Both mean BMI and BMI-SDS improved during the intervention independent of genotype. The mean systolic blood pressure was lowered and concentrations of HDL-cholesterol increased significantly.The obesity risk alleles of non-synonymous SNPs at SH2B1 and APOB48R have no strong effect on weight loss-related phenotypes in overweight children after a 1-year lifestyle intervention.

Do common variants separate between obese melanocortin-4 receptor gene mutation carriers and non-carriers? The impact of cryptic relatedness

BACKGROUND/AIMS

Genome-wide association studies revealed associations of single nucleotide polymorphisms (SNPs) flanking MC4R with body mass index variability and obesity. We genotyped 28 SNPs, covering MC4R, and searched for haplotypes discriminating between obese mutation carriers and non-carriers.

METHODS

We analyzed all three-marker haplotype combinations of the 28 SNPs to discriminate between obese mutation carriers and non-carriers - overall and in functional categories for 25 different MC4R mutations: (a) 'like wild type', (b) 'partial loss of function', and (c) 'complete loss of function'. We checked for the possible impact of 'cryptic relatedness' by sensitivity analyses including only 1 randomly selected patient per mutation.

RESULTS

Overall analyses revealed a haplotype of 3 SNPs downstream of the MC4R discriminating between obese mutation carriers and obese non-carriers. However, sensitivity analyses showed that the finding is most likely due to cryptic relatedness.

CONCLUSION

Given a mutation prevalence of 1-5%, the sample size of 62 obese mutation carriers with overall 25 different MC4R mutations represents a unique feature of our study. Taking MC4R as an example, we demonstrate the impact of cryptic relatedness when trying to link non-coding SNPs to functionally relevant mutations. Hence, a thorough mutation screen can currently not be guided by SNP genotyping.

No impact of obesity susceptibility loci on weight regain after a lifestyle intervention in overweight children

OBJECTIVE

An obesity risk allele at the NEGR1 locus was shown to be associated with weight regain after a lifestyle intervention in obese adults. Independent confirmation and studies in children are lacking. Therefore, we analyzed the impact of this and 11 additional obesity susceptibility loci on weight regain after a lifestyle intervention in overweight children.

DESIGN AND METHODS

We longitudinally analyzed the changes in weight status as body mass index standard deviation score (BMI-SDS) in 282 overweight children (10.6 ± 2.5 years, 47% male, BMI 27.1 ± 3.9 kg/m2) both at the end of a 1-year lifestyle intervention and at 1 year after the end of intervention. We genotyped obesity risk single nucleotide polymorphisms (SNPs) derived from genome-wide association studies in or in proximity to the following genes: NEGR1, TNKS, SDCCAG8, FTO, MC4R, TMEM18, PTER, MTCH2, SH2B1, MAF, NPC1, and KCTD15.

RESULTS

The children reduced their BMI-SDS (-0.28 ± 0.35; p<0.001) during intervention and increased their BMI-SDS between the end of intervention and 1 year later (+0.05 ± 0.36; p=0.027). None of the SNPs including NEGR1 was related significantly to weight regain.

CONCLUSIONS

We found no evidence for effects of any of the GWAS-based obesity marker alleles on weight regain in the course of 1 year after an intervention.

Significantly reducing post-tonsillectomy haemorrhage requiring surgery by suturing the faucial pillars: a retrospective analysis

Background

The tonsillectomy is one of the most frequently performed surgical procedures. Given the comparatively frequent postsurgical bleeding associated with this procedure, particular attention has been paid to reduction of the postoperative bleeding rate. In 2006, we introduced routine suturing of the faucial pillars at our clinic to reduce postoperative haemorrhage.

Methods

Two groups from the years 2003–2005 (n = 1000) and 2007–2009 (n = 1000) have been compared. We included all patients who had an elective tonsillectomy due to a benign, non-acute inflammatory tonsil illness. In the years 2007–2009, we additionally sutured the faucial pillars after completing haemostasis. For primary haemostasis we used suture ligation and bipolar diathermy.

Results

The rate of bleeding requiring second surgery for haemostasis was 3.6% in 2003–2005 but only 2.0% in 2007–2009 (absolute risk reduction 1.6% (95% CI 0.22%–2.45%, p = 0.04)). The median surgery time—including adenoidectomy and paracentesis surgery—increased from 25 to 31 minutes (p<0.01).

Conclusions

We have been able to substantiate that suturing of the faucial pillars nearly halves the rate of postoperative haemorrhage. Surgery takes 8 minutes longer on average. Bleeding occurs later, mostly after 24 h. The limitations of this study relate to its retrospective character and all the potential biases related to observational studies.

Prognostic significance of chromosome 3 alterations determined by microsatellite analysis in uveal melanoma: a long-term follow-up study

BACKGROUND

In uveal melanoma (UM), the most frequent primary intraocular tumour in adults, loss of one entire chromosome 3 (monosomy 3 (M3)) is observed in ~50% of tumours and is significantly associated with metastatic disease. The strong association of metastatic disease with M3 offers the opportunity for molecular prognostic testing of UM patients.

METHODS

To re-evaluate M3 as prognostic marker in our clinical and laboratory setting and to determine the metastatic potential of rare tumours with partial M3, we performed a comprehensive study on 374 UM patients treated by enucleation in our clinic within 10 consecutive years, starting in 1998. Genotyping of all tumours was performed by microsatellite analysis.

RESULTS

Median follow-up time was 5.2 years. The disease-specific mortality rates (death by UM metastases) for tumours with disomy 3 (D3) and M3 were 13.2% and 75.1%, respectively. The disease-specific survival was worse when M3 was observed together with chromosome 8 alterations (P=0.020). Death of UM metastases was also observed in 12 patients (9%) with D3 tumours. The metastasising D3 tumours showed a larger basal tumour diameter (P=0.007), and were more frequently of mixed or epitheloid cell type (P<0.0001) than D3 tumours that did not metastasise. Mortality rate of tumours showing partial M3 (8.3%) was as low as that for tumours with D3.

CONCLUSION

This shows that large tumours with disomy 3 have an increased risk to develop metastases. On the basis of these results, our clinic offers routine prognostic testing of UM patients by chromosome 3 typing.

The fatty acid amide hydrolase (FAAH) gene variant rs324420 AA/AC is not associated with weight loss in a 1-year lifestyle intervention for obese children and adolescents

Adult obese carriers of the A allele of SNP rs324420 in the fatty acid amide hydrolase (FAAH) gene lose more weight and improve associated phenotypes better than non-carriers during an intervention. We aimed to replicate this finding in obese children and adolescents undergoing a one year lifestyle intervention (Obeldicks program). A total of 453 overweight and obese children and adolescents (10.8±2.6 years, BMI-SDS 2.4±0.5; 55% girls) were genotyped for rs324420 (C/A) by restriction fragment length polymorphism (RFLP) analysis. Participants were prescribed a balanced diet, containing 55 En% carbohydrates, 30 En% fat, and 15 En% proteins. Moreover, they took part in an exercise therapy once a week. Blood was taken at baseline and after 1 year of intervention. Anthropometric (height, weight, BMI, and BMI-SDS) and plasma parameters (total cholesterol, LDL-cholesterol, HDL-cholesterol, triacylglycerides, glucose, insulin, and HOMA) as well as blood pressure were measured. Both mean BMI and BMI-SDS improved significantly. The mean systolic blood pressure was also lowered and concentrations of HDL-cholesterol increased significantly. However, none of the measured changes were associated with FAAH rs324420 AA/AC genotype. We did not detect evidence for an association of FAAH genotypes with weight reduction in overweight and obese children and adolescents. Hence, the previous finding in adults could not be confirmed. As the length (1 year as compared to 3 months) and mode of treatment (hypocaloric diet in adults vs. physical activity plus balanced meals) of the interventions varied, these parameters might have influenced the inconsistent results.

Genome-wide association study in German patients with attention deficit/hyperactivity disorder

The heritability of attention deficit hyperactivity disorder (ADHD) is approximately 0.8. Despite several larger scale attempts, genome-wide association studies (GWAS) have not led to the identification of significant results. We performed a GWAS based on 495 German young patients with ADHD (according to DSM-IV criteria; Human660W-Quadv1; Illumina, San Diego, CA) and on 1,300 population-based adult controls (HumanHap550v3; Illumina). Some genes neighboring the single nucleotide polymorphisms (SNPs) with the lowest P-values (best P-value: 8.38 × 10(-7)) have potential relevance for ADHD (e.g., glutamate receptor, metabotropic 5 gene, GRM5). After quality control, the 30 independent SNPs with the lowest P-values (P-values ≤ 7.57 × 10(-5) ) were chosen for confirmation. Genotyping of these SNPs in up to 320 independent German families comprising at least one child with ADHD revealed directionally consistent effect-size point estimates for 19 (10 not consistent) of the SNPs. In silico analyses of the 30 SNPs in the largest meta-analysis so far (2,064 trios, 896 cases, and 2,455 controls) revealed directionally consistent effect-size point estimates for 16 SNPs (11 not consistent). None of the combined analyses revealed a genome-wide significant result. SNPs in previously described autosomal candidate genes did not show significantly lower P-values compared to SNPs within random sets of genes of the same size. We did not find genome-wide significant results in a GWAS of German children with ADHD compared to controls. The second best SNP is located in an intron of GRM5, a gene located within a recently described region with an infrequent copy number variation in patients with ADHD.

Oxygen persufflation as adjunct in liver preservation (OPAL): study protocol for a randomized controlled trial

BACKGROUND

Early graft dysfunction due to preservation/reperfusion injury represents a dramatic event after liver transplantation. Enhancement of donor organ criteria, in order to cope with the ever increasing donor shortage, further increases graft susceptibility to ischemic alterations. Major parts of post-preservation injury, however, occur at the time of warm reperfusion but not during ischemic storage; successful reperfusion of ischemic tissue in turn depends on an adequate redox and intracellular signal homeostasis. The latter has been shown experimentally to be favorably influenced by oxygen persufflation within short time spans. Thus viability of marginally preserved liver grafts could still be augmented by transient hypothermic reconditioning even after normal procurement and static cold storage. The present study is aimed to confirm the conceptual expectations, that hypothermic reconditioning by gaseous oxygen persufflation is a useful method to suppress injurious cellular activation cascades and to improve post-ischemic recovery of marginally preserved liver grafts.

METHODS/DESIGN

OPAL is a prospective single center randomized proof of concept study, including two parallel groups in a total of 116 liver transplant patients. The effect of an in hospital treatment of the isolated liver graft by 2 hours of oxygen persufflation immediately prior to transplantation will be assesses as compared to standard procedure (cold storage without further intervention). The primary endpoint is the peak transaminase serum level (AST) during the first three days after transplantation as a surrogate readout for parenchymal liver injury. Other outcomes comprise patient and graft survival, time of intensive care requirement, hepatic tissue perfusion 1h after revascularisation, early onset of graft dysfunction based on coagulation parameters, as well as the use of a refined scoring-system for initial graft function based on a multi-parameter (AST, ALT, Quick and bilirubin) score. Furthermore, the effect of OPAL on molecular pathways of autophagy and inflammatory cell activation will be evaluated. Final analysis will be based on all participants as randomized (intention to treat).

TRIAL REGISTRATION

Current Controlled Trials ISRCTN00167887.

Missing heritability in the tails of quantitative traits? A simulation study on the impact of slightly altered true genetic models

OBJECTIVE

Genome-wide association studies have identified robust associations between single nucleotide polymorphisms and complex traits. As the proportion of phenotypic variance explained is still limited for most of the traits, larger and larger meta-analyses are being conducted to detect additional associations. Here we investigate the impact of the study design and the underlying assumption about the true genetic effect in a bimodal mixture situation on the power to detect associations.

METHODS

We performed simulations of quantitative phenotypes analysed by standard linear regression and dichotomized case-control data sets from the extremes of the quantitative trait analysed by standard logistic regression.

RESULTS

Using linear regression, markers with an effect in the extremes of the traits were almost undetectable, whereas analysing extremes by case-control design had superior power even for much smaller sample sizes. Two real data examples are provided to support our theoretical findings and to explore our mixture and parameter assumption.

CONCLUSIONS

Our findings support the idea to re-analyse the available meta-analysis data sets to detect new loci in the extremes. Moreover, our investigation offers an explanation for discrepant findings when analysing quantitative traits in the general population and in the extremes.

Toll-like receptor 4 single-nucleotide polymorphisms Asp299Gly and Thr399Ile in head and neck squamous cell carcinomas

Background

Chronic inflammation plays an important role in head and neck squamous cell carcinomas (HNSCC). This study addresses the impact of two single nucleotide polymorphisms (SNP) Asp299Gly and Thr399Ile of the toll-like receptor (TLR) 4 gene on the clinical outcome while accounting for the influence of adjuvant systemic therapy in a large cohort of HNSCC patients.

Methods

Genotype analysis was done using DNA from tissue samples from 188 patients with HNSCC; TLR4 protein expression was assessed immunohistochemically in tissue microarrays. Classical survival models were used for statistical analyses.

Results

Ten percent of patients with HNSCC presented with the TLR4 299Gly and 17% with the TLR4 399Ile allele. Patients with the heterozygous genotype TLR4 Asp299Gly had a significantly reduced disease-free and overall survival. Also, patients with the heterozygous genotype TLR4 Thr399Ile had a reduced disease-free survival. Notably, these associations seem to be attributable to relatively poor therapy response as e.g. reflected in a significantly shorter DFS among HNSCC patients carrying the Asp299Gly variant and receiving adjuvant systemic therapy.

Conclusion

According to this study, TLR4 299Gly und 399Ile alleles may serve as markers for prognosis of head and neck cancer in patients with adjuvant systemic therapy, particularly chemotherapy, and might indicate therapy resistance.

Impact of immunosuppressive therapy on hepatitis C infection after renal transplantation

BACKGROUND

Among patients after renal transplantation (NTx), hepatitis C virus (HCV) infection is a risk factor for graft loss and patient death caused by hepatic decompensation. Also, HCV has been implicated in the pathogenesis of glomerular diseases in native and transplanted kidneys. Therefore, the aim of this retrospective cohort study was to determine the effects of the widely used calcineurin inhibitors (CNI) cyclosporine A (CsA) and tacrolimus (Tac) on hepatitis C virus replication, inflammatory activity, development of liver fibrosis, and long-term renal graft function.

SUBJECTS AND METHODS

A cohort of 71 patients with HCV infection after kidney transplantation under immunosuppression with either CsA or Tac were analyzed for viral kinetics and serum transaminases. In addition, presence of liver fibrosis was detected by non-invasive measurements using the FibroScan. Graft function was determined biochemically. Patients with interferon therapy prior to transplantation were excluded from the study in order to avoid any impact of the antiviral therapy on outcomes.

RESULTS

In the early period after transplantation, hepatitis C viral load was lower in patients treated with Tac as compared to CsA. This effect became negligible 3 months after transplantation. However, hepatic inflammatory activity was reduced in the CsA-treated group. Extent of liver fibrosis was similar in both groups of HCV-infected patients as well as in a control group of non-HCV-infected patients after renal transplantation (NTx), respectively. Renal function and glomerular filtration rate, as calculated by the modification of diet in renal disease (MDRD) formula, were significantly better in patients treated with Tac.

CONCLUSIONS

During long-term immunosuppression, the CNIs cyclosporine A versus tacrolimus showed no significant differences in HCV-infected patients after renal transplantation with respect to viral replication and development of liver fibrosis. However, function of the renal graft is significantly better preserved in patients receiving tacrolimus.