Stereology shows that damaged liver recovers after protein refeeding

Objective: The aim of the present study was to investigate the putative effects of a low-protein diet on the three-dimensional structure of hepatocytes and determine whether this scenario could be reversed by restoring the adequate levels of protein to the diet. Methods: Using design-based stereology, the total number and volume of hepatocytes were estimated in the liver of mice in healthy and altered (by protein malnutrition) conditions and after protein renutrition. Results: This study demonstrated a 65% decrease in the liver volume (3302 mm3 for the control for undernourished versus 1141 mm3 for the undernourished group) accompanied by a 46% reduction in the hepatocyte volume (8223 μm3 for the control for undernourished versus 4475 μm3 for the undernourished group) and a 90% increase in the total number of binucleate hepatocytes (1 549 393 for the control for undernourished versus 2 941 353 for the undernourished group). Reinstating a normoproteinic diet (12% casein) proved to be effective in restoring the size of hepatocytes, leading to an 85% increase in the total number of uninucleate hepatocytes (15 988 560 for the undernourished versus 29 600 520 for the renourished group), and partially reversed the liver atrophy. Conclusions: Awareness of these data will add to a better morphologic understanding of malnutrition-induced hepatopathies and will help clinicians improve the diagnosis and treatment of this condition in humans and in veterinary practice

A Factorization Law for Entanglement Decay

We present a simple and general factorization law for quantum systems shared by two parties, which describes the time evolution of entanglement upon passage of either component through an arbitrary noisy channel. The robustness of entanglement-based quantum information processing protocols is thus easily and fully characterized by a single quantity.Comment: 4 pages, 5 figure

Analyzing Ideological Communities in Congressional Voting Networks

We here study the behavior of political party members aiming at identifying how ideological communities are created and evolve over time in diverse (fragmented and non-fragmented) party systems. Using public voting data of both Brazil and the US, we propose a methodology to identify and characterize ideological communities, their member polarization, and how such communities evolve over time, covering a 15-year period. Our results reveal very distinct patterns across the two case studies, in terms of both structural and dynamic properties

Antimicrobial Peptides and Skin: A Paradigm of Translational Medicine

Antimicrobial peptides (AMPs) are small, cationic, amphiphilic peptides with broad-spectrum microbicidal activity against both bacteria and fungi. In mammals, AMPs form the first line of host defense against infections and generally play an important role as effector agents of the innate immune system. The AMP era was born more than 6 decades ago when the first cationic cyclic peptide antibiotics, namely polymyxins and tyrothricin, found their way into clinical use. Due to the good clinical experience in the treatment of, for example, infections of mucus membranes as well as the subsequent understanding of mode of action, AMPs are now considered for treatment of inflammatory skin diseases and for improving healing of infected wounds. Based on the preclinical findings, including pathobiochemistry and molecular medicine, targeted therapy strategies are developed and first results indicate that AMPs influence processes of diseased skin. Importantly, in contrast to other antibiotics, AMPs do not seem to propagate the development of antibiotic-resistant micro-organisms. Therefore, AMPs should be tested in clinical trials for their efficacy and tolerability in inflammatory skin diseases and chronic wounds. Apart from possible fields of application, these peptides appear suited as an example of the paradigm of translational medicine for skin diseases which is today seen as a `two-way road' - from bench to bedside and backwards from bedside to bench. Copyright (c) 2012 S. Karger AG, Base

C-Terminal Mutants of Apolipoprotein L-I Efficiently Kill Both Trypanosoma brucei brucei and Trypanosoma brucei rhodesiense

Apolipoprotein L-I (apoL1) is a human-specific serum protein that kills Trypanosoma brucei through ionic pore formation in endosomal membranes of the parasite. The T. brucei subspecies rhodesiense and gambiense resist this lytic activity and can infect humans, causing sleeping sickness. In the case of T. b. rhodesiense, resistance to lysis involves interaction of the Serum Resistance-Associated (SRA) protein with the C-terminal helix of apoL1. We undertook a mutational and deletional analysis of the C-terminal helix of apoL1 to investigate the linkage between interaction with SRA and lytic potential for different T. brucei subspecies. We confirm that the C-terminal helix is the SRA-interacting domain. Although in E. coli this domain was dispensable for ionic pore-forming activity, its interaction with SRA resulted in inhibition of this activity. Different mutations affecting the C-terminal helix reduced the interaction of apoL1 with SRA. However, mutants in the L370-L392 leucine zipper also lost in vitro trypanolytic activity. Truncating and/or mutating the C-terminal sequence of human apoL1 like that of apoL1-like sequences of Papio anubis resulted in both loss of interaction with SRA and acquired ability to efficiently kill human serum-resistant T. b. rhodesiense parasites, in vitro as well as in transgenic mice. These findings demonstrate that SRA interaction with the C-terminal helix of apoL1 inhibits its pore-forming activity and determines resistance of T. b. rhodesiense to human serum. In addition, they provide a possible explanation for the ability of Papio serum to kill T. b. rhodesiense, and offer a perspective to generate transgenic cattle resistant to both T. b. brucei and T. b. rhodesiense