Magnetic resonance imaging frequently changes classification of acute traumatic thoracolumbar spine injuries

Objective: To evaluate the influence of additional (MRI) compared with computed tomography (CT) alone for the classification of traumatic spinal injuries using the Arbeitsgemeinshaft für Osteosynthesefragen (AO) system and the Thoraco-Lumbar Injury Classification and Severity (TLICS) scale. Materials and methods: Images from 100 consecutive patients with at least one fracture on CT were evaluated retrospectively by three radiologists with regard to the AO and TLICS classification systems in 2 steps. First, all images from the initial CT examination were analyzed. Second, 6weeks later, CT and MR images were analyzed together. Descriptive statistics and Wilcoxon tests were performed to identify changes in the number of fractures and ligamentous lesions detected and their corresponding classification. Results: CT and MRI together revealed a total of 196 fractures (CT alone 162 fractures). The AO classification changed in 31%, the TLICS classification changed in 33% of the patients compared with CT alone. Based on CT and MRI together, the TLICS value changed from values < 5 (indication for conservative therapy) to values ≥ 5 (indication for surgical therapy) in 24%. Conclusion: MRI of patients with thoracolumbar spinal trauma considerably improved the detection of fractures and soft tissue injuries compared with CT alone and significantly changed the overall trauma classificatio

Y Chromosomal Variation Tracks the Evolution of Mating Systems in Chimpanzee and Bonobo

The male-specific regions of the Y chromosome (MSY) of the human and the chimpanzee (Pan troglodytes) are fully sequenced. The most striking difference is the dramatic rearrangement of large parts of their respective MSYs. These non-recombining regions include ampliconic gene families that are known to be important for male reproduction,and are consequently under significant selective pressure. However, whether the published Y-chromosomal pattern of ampliconic fertility genes is invariable within P. troglodytes is an open but fundamental question pertinent to discussions of the evolutionary fate of the Y chromosome in different primate mating systems. To solve this question we applied fluorescence in situ hybridisation (FISH) of testis-specific expressed ampliconic fertility genes to metaphase Y chromosomes of 17 chimpanzees derived from 11 wild-born males and 16 bonobos representing seven wild-born males. We show that of eleven P. troglodytes Y-chromosomal lines, ten Y-chromosomal variants were detected based on the number and arrangement of the ampliconic fertility genes DAZ (deleted in azoospermia) and CDY (chromodomain protein Y)—a so-far never-described variation of a species' Y chromosome. In marked contrast, no variation was evident among seven Y-chromosomal lines of the bonobo, P. paniscus, the chimpanzee's closest living relative. Although, loss of variation of the Y chromosome in the bonobo by a founder effect or genetic drift cannot be excluded, these contrasting patterns might be explained in the context of the species' markedly different social and mating behaviour. In chimpanzees, multiple males copulate with a receptive female during a short period of visible anogenital swelling, and this may place significant selection on fertility genes. In bonobos, however, female mate choice may make sperm competition redundant (leading to monomorphism of fertility genes), since ovulation in this species is concealed by the prolonged anogenital swelling, and because female bonobos can occupy high-ranking positions in the group and are thus able to determine mate choice more freely

Y-Chromosome Variation in Hominids: Intraspecific Variation Is Limited to the Polygamous Chimpanzee

The original publication is available at www.plosone.orgBackground: We have previously demonstrated that the Y-specific ampliconic fertility genes DAZ (deleted in azoospermia) and CDY (chromodomain protein Y) varied with respect to copy number and position among chimpanzees (Pan troglodytes). In comparison, seven Y-chromosomal lineages of the bonobo (Pan paniscus), the chimpanzee’s closest living relative, showed no variation. We extend our earlier comparative investigation to include an analysis of the intraspecific variation of these genes in gorillas (Gorilla gorilla) and orangutans (Pongo pygmaeus), and examine the resulting patterns in the light of the species’ markedly different social and mating behaviors. Methodology/Principal Findings: Fluorescence in situ hybridization analysis (FISH) of DAZ and CDY in 12 Y-chromosomal lineages of western lowland gorilla (G. gorilla gorilla) and a single lineage of the eastern lowland gorilla (G. beringei graueri) showed no variation among lineages. Similar findings were noted for the 10 Y-chromosomal lineages examined in the Bornean orangutan (Pongo pygmaeus), and 11 Y-chromosomal lineages of the Sumatran orangutan (P. abelii). We validated the contrasting DAZ and CDY patterns using quantitative real-time polymerase chain reaction (qPCR) in chimpanzee and bonobo. Conclusion/Significance: High intraspecific variation in copy number and position of the DAZ and CDY genes is seen only in the chimpanzee. We hypothesize that this is best explained by sperm competition that results in the variant DAZ and CDY haplotypes detected in this species. In contrast, bonobos, gorillas and orangutans—species that are not subject to sperm competition—showed no intraspecific variation in DAZ and CDY suggesting that monoandry in gorillas, and preferential female mate choice in bonobos and orangutans, probably permitted the fixation of a single Y variant in each taxon. These data support the notion that the evolutionary history of a primate Y chromosome is not simply encrypted in its DNA sequences, but is also shaped by the social and behavioral circumstances under which the specific species has evolved.Funded by the Deutsche Forschungsgemeinschaft (SCHE 214/8)Publisher's versio

Intermethod agreement and interobserver correlation of radiologic acromiohumeral distance measurements

The acromiohumeral distance (AHD) measured on conventional, true anteroposterior radiographs taken with the patient standing and the arm held in neutral rotation can predict the presence or absence of a large, chronic rotator cuff tears, and narrowing of the acromiohumeral distance can predict irreparability of rotator cuff tears. The relation between AHD measured on conventional radiographs and the integrity of the rotator cuff tendons is well known. Conversely, the correlation between the AHD on conventional radiographs and that measured on magnetic resonance imaging (MRI) or computed tomography (CT) scans is unknown. It has also not been determined which method correlates better with fatty infiltration of the rotator cuff muscles and might thereby be a better prognostic value for the outcome of rotator cuff repair. Conventional radiographs, plus MRI and or CT studies taken at the same time of patients with rotator cuff tears, shoulder instability, primary glenohumeral osteoarthritis, or idiopathic frozen shoulder, were randomly selected, and the AHD was measured both on conventional radiographs and on MRI or CT. The values were correlated with the stage of fatty degeneration of the rotator cuff muscles in the cases of rotator cuff tears. The AHD on conventional radiographs was larger than on MRI and CT, and correlation of the values measured (conventional radiography vs MRI and CT) could be demonstrated. For rotator cuff diseases, a significant but moderate correlation (r = 0.6; P < .05) between conventional and MRI was identified, and the conventional values were approximately 0.6 mm greater than the corresponding MRI values. It is, therefore, possible to use the AHD read on MRI or CT studies for prognostic reasons, provided the values obtained are converted accordingly and remembering that the correlation of the values is only moderate