Prävalenz und Morphologie überzähliger Zähne in der Bevölkerung einer Schweizer Gemeinde: Short communication

Ziel der Studie war die Ermittlung der aktuellen Prävalenz überzähliger Zähne in der Bevölkerung einer Schweizer Gemeinde. Als Grundlage dienten 3004 routinemässig angefertigte Orthopantomogramme aus dem alljährlichen Schuluntersuch der Stadt Winterthur während der Jahre 1990–2005 (Durchschnittsalter 9,45 Jahre, 1391 Mädchen, 1613 Knaben bei einer Streuung von 6 bis 15 Jahren). Die Studie fand 44 überzählige Zähne. Dieser Anteil ergibt eine Prävalenz von 1,5%. Die Prävalenz bei den Knaben lag mit 1,1% höher als bei den Mädchen, die mit 0,4% davon betroffen waren. Der grösste Teil überzähliger Zähne war in der oberen Front zu finden (38 von 44 Zähnen, 86%). Davon waren 33 aufgrund ihrer Lage als Mesiodentes zu bezeichnen. Fünf überzählige Zähne hatten die gleiche Form wie die eines oberen lateralen Schneidezahnes. In der Unterkieferfront fanden sich 5 überzählige Zähne mit gleicher Form wie die bleibenden unteren Inzisiven. Die überzähligen Zähne hatten zu 70% eine konische Zahnform. Die Prävalenz überzähliger Zähne ist mit 1,5% niedrig und vergleichbar mit ähnlichen Studien in der Literatur. Die meisten überzähligen Zähne (86%) sind in der Oberkieferfront angesiedelt.Bei Retentionen und Durchbruchsstörungen von Zähnen in dieser Region sollte in Betracht gezogen werden, dass überzählige Zähne Ursache dafür sein könnten

Updates in the field of hereditary nonpolyposis colorectal cancer : Expert Review of Gastroenterology & Hepatology

ABSTRACT Introduction Up to one third of colorectal cancers show familial clustering and 5% are hereditary single-gene disorders. Hereditary non-polyposis colorectal cancer comprises DNA mismatch repair-deficient and -proficient subsets, represented by Lynch syndrome (LS) and familial colorectal cancer type X (FCCTX), respectively. Accurate knowledge of molecular etiology and genotype-phenotype correlations are critical for tailored cancer prevention and treatment. Areas covered The authors highlight advances in the molecular dissection of hereditary non-polyposis colorectal cancer, based on recent literature retrieved from PubMed. Future possibilities for novel gene discoveries are discussed. Expert commentary LS is molecularly well established, but new information is accumulating of the associated clinical and tumor phenotypes. FCCTX remains poorly defined, but several promising candidate genes have been discovered and share some preferential biological pathways. Multi-level characterization of specimens from large patient cohorts representing multiple populations, combined with proper bioinformatic and functional analyses, will be necessary to resolve the outstanding questions.Peer reviewe

Response to Yang et al

Non peer reviewe

Sequencing of Lynch syndrome tumors reveals the importance of epigenetic alterations

Genomic instability and epigenetic aberrations are important classifiers of human tumors, yet, their interrelations are poorly understood. We used Lynch syndrome (LS) to address such relationships. Forty-five tumors (11 colorectal adenomas, 18 colorectal carcinomas, and 16 ovarian carcinomas) were profiled for CpG Island Methylator Phenotype (CIMP) and somatic mutations. All tumors showed high-degree microsatellite instability. Panel sequencing of 578 cancer-relevant genes revealed the average number of 1433, 1124, and 657 non-synonymous somatic mutations per colorectal adenoma, colorectal carcinoma, and ovarian carcinoma, respectively. Genes harboring mutations with allele frequency 25 % or higher in at least 31 % of tumors were regarded to be possible drivers. Among 72 and 10 such genes identified in colorectal and ovarian tumors, respectively, the most frequently mutated genes BRD4 and MLL2 (62 % of colorectal tumors) and ARID1A (50 % of ovarian carcinomas) are involved in epigenetic regulation. The total number of somatic mutations or mutant genes per tumor were significantly associated with CIMP. Our results suggest that even in an inherited disease, tumor type-specific epigenetic changes are significant and may result from regulatory changes (CIMP) or structural events (mutations of epigenetic regulatory genes). The findings are clinically relevant since many of the affected pathways can be therapeutically targeted.Peer reviewe

Pseudoexons provide a mechanism for allele-specific expression of APC in familial adenomatous polyposis

Allele-specific expression (ASE) of the Adenomatous Polyposis Coli (APC) gene occurs in up to one-third of families with adenomatous polyposis (FAP) that have screened mutation-negative by conventional techniques. To advance our understanding of the genomic basis of this phenomenon, 54 APC mutation-negative families (21 with classical FAP and 33 with attenuated FAP, AFAP) were investigated. We focused on four families with validated ASE and scrutinized these families by sequencing of the blood transcriptomes (RNA-seq) and genomes (WGS). Three families, two with classical FAP and one with AFAP, revealed deep intronic mutations associated with pseudoexons. In all three families, intronic mutations (c.646-1806T > G in intron 6, c.1408+729A > G in intron 11, and c.1408+731C > T in intron 11) created new splice donor sites resulting in the insertion of intronic sequences (of 127 bp, 83 bp, and 83 bp, respectively) in the APC transcript. The respective intronic mutations were absent in the remaining polyposis families and the general population. Premature stop of translation as the predicted consequence as well as co-segregation with polyposis supported the pathogenicity of the pseudoexons. We conclude that next generation sequencing on RNA and genomic DNA is an effective strategy to reveal and validate pseudoexons that are regularly missed by traditional screening methods and is worth considering in apparent mutation-negative polyposis families.Instituto Multidisciplinario de Biología Celula

Emergence of a non-scaling degree distribution in bipartite networks: a numerical and analytical study

We study the growth of bipartite networks in which the number of nodes in one of the partitions is kept fixed while the other partition is allowed to grow. We study random and preferential attachment as well as combination of both. We derive the exact analytical expression for the degree-distribution of all these different types of attachments while assuming that edges are incorporated sequentially, i.e., a single edge is added to the growing network in a time step. We also provide an approximate expression for the case when more than one edge are added in a time step. We show that depending on the relative weight between random and preferential attachment, the degree-distribution of this type of network falls into one of four possible regimes which range from a binomial distribution for pure random attachment to an u-shaped distribution for dominant preferential attachment

Self-reported temporomandibular disorder symptoms and severity of malocclusion in prospective orthognathic-surgical patients

Objective: The objective of this study is to analyze the association between self-reported symptoms of temporomandibular joint disorder (TMD) and the severity of malocclusion in prospective orthognathic-surgical patients.Material and methods: The subjects consisted of 50 consecutive patients (13 males and 37 females) referred to two university clinics for assessment of orthodontic-surgical treatment need. Data considering self-reported TMD symptoms were gathered using a semi-structured diary. At the first appointment, all patients rated the importance of treatment (on a scale of 1-10) and assessed self-perceived dental appearance using a VAS scale. The scale was anchored with photographs 1 and 10 from the Aesthetic Component (AC) of the Index of Orthodontic Treatment Need (IOTN). Study models were assessed by an experienced orthodontic specialist using the Peer Assessment Rating (PAR) index and the Index of Complexity, Outcome and Need (ICON). Association between the PAR and ICON scores and the number of reported symptoms was analyzed statistically.Results: Seventy-one percent of patients reported experiencing TMD symptoms. The most prevalent symptoms were pain in the head and/or neck region and fatigue in the TMJ region. The number of symptoms was highest in the morning. Ninety percent of males and 86% of females rated the importance of treatment as high; males experiencing TMD symptoms tended to rate surgery as more important compared with males with no symptoms (p=0.056).Conclusions: In this sample, the results cannot unambiguously confirm an association between self-reported symptoms of TMD and objectively defined severity of malocclusion

Correlations in Bipartite Collaboration Networks

Collaboration networks are studied as an example of growing bipartite networks. These have been previously observed to have structure such as positive correlations between nearest-neighbour degrees. However, a detailed understanding of the origin of this phenomenon and the growth dynamics is lacking. Both of these are analyzed empirically and simulated using various models. A new one is presented, incorporating empirically necessary ingredients such as bipartiteness and sublinear preferential attachment. This, and a recently proposed model of team assembly both agree roughly with some empirical observations and fail in several others.Comment: 13 pages, 17 figures, 2 table, submitted to JSTAT; manuscript reorganized, figures and a table adde

Body Weight, Physical Activity, and Risk of Cancer in Lynch Syndrome

Lynch syndrome (LS) increases cancer risk. There is considerable individual variation in LS cancer occurrence, which may be moderated by lifestyle factors, such as body weight and physical activity (PA). The potential associations of lifestyle and cancer risk in LS are understudied. We conducted a retrospective study with cancer register data to investigate associations between body weight, PA, and cancer risk among Finnish LS carriers. The participants (n = 465, 54% women) self-reported their adulthood body weight and PA at 10-year intervals. Overall cancer risk and colorectal cancer (CRC) risk was analyzed separately for men and women with respect to longitudinal and near-term changes in body weight and PA using extended Cox regression models. The longitudinal weight change was associated with an increased risk of all cancers (HR 1.02, 95% CI 1.00–1.04) and CRC (HR 1.03, 1.01–1.05) in men. The near-term weight change was associated with a lower CRC risk in women (HR 0.96, 0.92–0.99). Furthermore, 77.6% of the participants retained their PA category over time. Men in the high-activity group had a reduced longitudinal cancer risk of 63% (HR 0.37, 0.15–0.98) compared to men in the low-activity group. PA in adulthood was not associated with cancer risk among women. These results emphasize the role of weight maintenance and high-intensity PA throughout the lifespan in cancer prevention, particularly in men with LS