Transport of Schistosoma japonicum cercariae and the feasibility of niclosamide for cercariae control

Field experiments were conducted in southwestern China to estimate the distances over which cercariae of Schistosoma japonicum are transported and remain infective in village irrigation ditches and to determine the feasibility of interrupting this transport using niclosamide, the molluscicide commonly used for snail control in this environment. The number of worms recovered from bioassay mice downstream from experimentally introduced cercariae, but without niclosamide, decreased about 90% over the first 100 m of ditch and then remained essentially constant for the remaining 300 m of the ditch that was monitored. The niclosamide experiments resulted first in the finding that it was possible to achieve ditch average concentrations close to the target values of 0.25 ppm, but that concentrations at any particular location varied by a factor of up to 3. There was no correlation between water turbidity and niclosamide concentration. An average water concentration of 0.29 ppm resulted in no viable cercariae after a contact time of about 1 min and a travel distance of only 10 m. We regard these results as proof of the feasibility of chemical interruption of transport of S. japonicum cercariae although the toxicity of niclosamide to fish at the levels used here make it a questionable candidate for routine use.     

Single, context-specific glycans can target misfolded glycoproteins for ER-associated degradation

The endoplasmic reticulum (ER) maintains an environment essential for secretory protein folding. Consequently, the premature transport of polypeptides would be harmful to the cell. To avert this scenario, mechanisms collectively termed "ER quality control" prevent the transport of nascent polypeptides until they properly fold. Irreversibly misfolded molecules are sorted for disposal by the ER-associated degradation (ERAD) pathway. To better understand the relationship between quality control and ERAD, we studied a new misfolded variant of carboxypeptidase Y (CPY). The molecule was recognized and retained by ER quality control but failed to enter the ERAD pathway. Systematic analysis revealed that a single, specific N-linked glycan of CPY was required for sorting into the pathway. The determinant is dependent on the putative lectin-like receptor Htm1/Mnl1p. The discovery of a similar signal in misfolded proteinase A supported the generality of the mechanism. These studies show that specific signals embedded in glycoproteins can direct their degradation if they fail to fold.     

Returning genetic research results to individuals: points-to-consider

This paper is intended to stimulate debate amongst stakeholders in the international research community on the topic of returning individual genetic research results to study participants. Pharmacogenetics and disease genetics studies are becoming increasingly prevalent, leading to a growing body of information on genetic associations for drug responsiveness and disease susceptibility with the potential to improve health care. Much of these data are presently characterized as exploratory (non-validated or hypothesis-generating). There is, however, a trend for research participants to be permitted access to their personal data if they so choose. Researchers, sponsors, patient advocacy groups, ethics committees and regulatory authorities are consequently confronting the issue of whether, and how, study participants might receive their individual results. Noted international ethico-legal guidelines and public policy positions in Europe and the United States are reviewed for background. The authors offer 'Points-to-Consider' regarding returning results in the context of drug development trials based on their knowledge and experience. Theses considerations include: the clinical relevance of data, laboratory qualifications, informed consent procedures, confidentiality of medical information and the competency of persons providing results to participants. The discussion is framed as a benefit-to-risk assessment to balance the potential positive versus negative consequences to participants, while maintaining the integrity and feasibility of conducting genetic research studies.     

The alpha-fetoprotein promoter is the target of Afr1-mediated postnatal repression

The alpha-fetoprotein (AFP) gene is transcribed at high levels in the fetal liver and is repressed at birth, leading to low but detectable levels of AFP mRNA in the adult liver. This repression is regulated, in part, by a locus that is unlinked to AFP called Alpha-fetoprotein regulator 1 (Afr1). Previous studies showed that Afr1 regulation is independent of the AFP enhancers but requires the 1-kb AFP promoter/repressor region. Here, we demonstrate that a transgene with the 250-bp AFP promoter region linked to AFP enhancer element EII is expressed in the fetal liver and is postnatally repressed. In addition, this transgene is regulated by Afr1. These data indicate that the promoter is involved in postnatal AFP repression. Furthermore, we provide a high-resolution map of the Afr1 locus on mouse chromosome 15.     

Phototrophic Phylotypes Dominate Mesothermal Microbial Mats Associated with Hot Springs in Yellowstone National Park

The mesothermal outflow zones (50-65°C) of geothermal springs often support an extensive zone of green and orange laminated microbial mats. In order to identify and compare the microbial inhabitants of morphologically similar green-orange mats from chemically and geographically distinct springs, we generated and analyzed small-subunit ribosomal RNA (rRNA) gene amplicons from six mesothermal mats (four previously unexamined) in Yellowstone National Park. Between three and six bacterial phyla dominated each mat. While many sequences bear the highest identity to previously isolated phototrophic genera belonging to the Cyanobacteria, Chloroflexi, and Chlorobi phyla, there is also frequent representation of uncultured, unclassified members of these groups. Some genus-level representatives of these dominant phyla were found in all mats, while others were unique to a single mat. Other groups detected at high frequencies include candidate divisions (such as the OP candidate clades) with no cultured representatives or complete genomes available. In addition, rRNA genes related to the recently isolated and characterized photosynthetic acidobacterium "Candidatus Chloracidobacterium thermophilum" were detected in most mats. In contrast to microbial mats from well-studied hypersaline environments, the mesothermal mats in this study accrue less biomass and are substantially less diverse, but have a higher proportion of known phototrophic organisms. This study provides sequences appropriate for accurate phylogenetic classification and expands the molecular phylogenetic survey of Yellowstone microbial mats.     

4-Piperidin-4-ylidenemethyl-benzamides as δ-opioid receptor agonists for CNS indications: identifying clinical candidates

A series of 4-piperidin-4-ylidenemethyl-benzamide δ-opioid receptor agonists is described with an emphasis on balancing the potency, subtype selectivity and in vitro ADME and safety properties. The three sites impacting SAR are substitutions on the aryl group (R(1)), the piperidine nitrogen (R(2)), and the amide (R(3)). Each region contributes to the balance of properties for δ opioid activity and a desirable CNS profile, and two clinical candidates (20 and 24) were advanced.     

Species loss of stoneflies (Plecoptera) in the Czech Republic during the 20th century

1. Rapid expansion and intensification of anthropogenic activities in the 20th century has caused profound changes in freshwater assemblages. Unfortunately, knowledge of the extent and causes of species loss (SL) is limited due to the lack of reliable historical data. An unusual data set allows us to compare changes in the most sensitive of aquatic insect orders, the Plecoptera, at some 170 locations in the Czech Republic between two time periods, 1955–1960 and 2006–2010. Historical data (1890–1911) on assemblages of six lowland rivers allow us to infer even earlier changes. 2. Regional stonefly diversity decreased in the first half of the 20th century. Streams at lower altitudes lost a substantial number of species, which were never recovered. In the second half of the century, large‐scale anthropogenic pressure caused SL in all habitats, leading to a dissimilarity of contemporary and previous assemblages. The greatest changes were found at sites affected by organic pollution and a mixture of organic pollution and channelisation or impoundment. Colonisation of new habitats was observed in only three of the 80 species evaluated. 3. Species of moderate habitat specialisation and tolerance to organic pollution were most likely to be lost. Those with narrow specialisations in protected habitats were present in both historical and contemporary collections. 4. Contemporary assemblages are the consequence of more than a 100 years of anthropogenic impacts. In particular, streams at lower altitude and draining intensively exploited landscapes host a mere fragment of the original species complement. Most stonefly species are less frequently present than before, although their assemblages remain almost intact in near‐natural mountain streams. Our analyses demonstrate dramatic restriction of species ranges and, in some cases, apparent changes in altitudinal preference throughout the area.     

Systems analysis of primary Sjögren's syndrome pathogenesis in salivary glands identifies shared pathways in human and a mouse model

Bone tissue has an exceptional quality to regenerate to native tissue in response to injury. However, the fracture repair process requires mechanical stability or a viable biological microenvironment or both to ensure successful healing to native tissue. An improved understanding of the molecular and cellular events that occur during bone repair and remodeling has led to the development of biologic agents that can augment the biological microenvironment and enhance bone repair. Orthobiologics, including stem cells, osteoinductive growth factors, osteoconductive matrices, and anabolic agents, are available clinically for accelerating fracture repair and treatment of compromised bone repair situations like delayed unions and nonunions. Preclinical and clinical studies using biologic agents like recombinant bone morphogenetic proteins have demonstrated an efficacy similar or better than that of autologous bone graft in acute fracture healing. A lack of standardized outcome measures for comparison of biologic agents in clinical fracture repair trials, frequent off-label use, and a limited understanding of the biological activity of these agents at the bone repair site have limited their efficacy in clinical applications.