Potential impact of screening for fatty liver disease by transient elastography with liver stiffness and controlled attenuation parameter measurements: a pilot study.

Background The prevalence of chronic liver diseases is high in developed countries, and the leading causes are amenable to prevention. The German Lebertag is to increase awareness of the burden of chronic liver diseases in the general public. We performed a pilot study using transient elastography with liver stiffness measurement (LSM) and the controlled attenuation parameter (CAP) as a screening tool for previously unrecognized liver diseases. Patients and methods LSM and CAP was performed in 60 individuals, and participants filled in a questionnaire reporting basic characteristics and past medical history. Results Median LSM and CAP values were within the normal range. Participants with self-reported diabetes mellitus had significantly elevated LSM (p = 0.02) and CAP values (p = 0.002). Participants with a BMI > 30 kg/m2 or dyslipidemia had significantly elevated CAP values (p = 0.007 and p = 0.01, respectively) with normal LSM values. Overall, 35 % of participants had elevated CAP values, indicating a high prevalence of hepatic steatosis. Discussion In a German pilot study, diabetes mellitus was a key risk factor for increased LSM and CAP values. Prevalence of steatosis was high and comparable to other Western countries. Transient elastography is a valuable tool to identify patients with increased risk for metabolic liver diseases. In people without risk factors, LSM and CAP values were within the normal range, indicating that screening for chronic liver injury was not warranted.

Evaluating intraspecific "network" construction methods using simulated sequence data: do existing algorithms outperform the global maximum parsimony approach?

In intraspecific studies, reticulated graphs are valuable tools for visualization, within a single figure, of alternative genealogical pathways among haplotypes. As available software packages implementing the global maximum parsimony (MP) approach only give the possibility to merge resulting topologies into less-resolved consensus trees, MP has often been neglected as an alternative approach to purely algorithmic (i.e., methods defined solely on the basis of an algorithm) "network" construction methods. Here, we propose to search tree space using the MP criterion and present a new algorithm for uniting all equally most parsimonious trees into a single (possibly reticulated) graph. Using simulated sequence data, we compare our method with three purely algorithmic and widely used graph construction approaches (minimum-spanning network, statistical parsimony, and median-joining network). We demonstrate that the combination of MP trees into a single graph provides a good estimate of the true genealogy. Moreover, our analyses indicate that, when internal node haplotypes are not sampled, the median-joining and MP methods provide the best estimate of the true genealogy whereas the minimum-spanning algorithm shows very poor performances.

Evidence for male dispersal along the coasts but no migration in pelagic waters in dusky dolphins (Lagenorhynchus obscurus).

Using nine nuclear species-specific microsatellite loci and two mitochondrial gene fragments (cytochrome b and control region), we investigated the processes that have shaped the geographical distribution of genetic diversity exhibited by contemporary dusky dolphin (Lagenorhynchus obscurus) populations. A total of 221 individuals from four locations (Peru, Argentina, southern Africa, and New Zealand) were assayed, covering most of the species' distribution range. Although our analyses identify a general demographic decline in the Peruvian dusky dolphin stock (recently affected by high natural and human-induced mortality levels), comparison between the different molecular markers hint at an ancient bottleneck that predates recent El Niño oscillations and human exploitation. Moreover, we find evidence of a difference in dispersal behaviour of dusky dolphins along the South American coast and across the Atlantic. While data in Peruvian and Argentine waters are best explained by male-specific gene flow between these two populations, our analyses suggest that dusky dolphins from Argentina and southern Africa recently separated from an ancestral Atlantic population and, since then, diverged without considerable gene flow. The inclusion of a few New Zealand samples further confirms the low levels of genetic differentiation among most dusky dolphin populations. Only the Peruvian dusky dolphin stock is highly differentiated, especially at mitochondrial loci, suggesting that major fluctuations in its population size have led to an increased rate of genetic drift.