Medical Researchers' Ancillary Care Obligations: The Relationship‐Based Approach

In this article, I provide a new account of the basis of medical researchers' ancillary care obligations. Ancillary care in medical research, or medical care that research participants need but that is not required for the validity or safety of a study or to redress research injuries, is a topic that has drawn increasing attention in research ethics over the last ten years. My view, the relationship‐based approach, improves on the main existing theory, Richardson and Belsky's ‘partial‐entrustment model’, by avoiding its problematic restriction on the scope of health needs for which researchers could be obligated to provide ancillary care. Instead, it grounds ancillary care obligations in a wide range of morally relevant features of the researcher‐participant relationship, including the level of engagement between researchers and participants, and weighs these factors against each other. I argue that the level of engagement, that is, the duration and intensity of interactions, between researchers and participants matters for ancillary care because of its connection to the meaningfulness of a relationship, and I suggest that other morally relevant features can be grounded in researchers' role obligations.     

The effect of selenium on cell proliferation in liver and colon

Epidemiologic and experimental evidence support a chemoprotective role for selenium (Se) in malignancy. Many mechanisms have been proposed to explain this phenomenon. In this study, the effect of Se intake on proliferation of hepatocytes and normal colonic epithelial cells in rats was determined using autoradiographic analysis of thymidine incorporation into DNA. Hepatocyte proliferation was measured 24 h after partial hepatectomy. Selenium-dosed animals demonstrated a significant reduction in hepatocyte labeling compared to the control group (6.1±2.6 vs 29.2±15.6,p=0.003). However, Se dosing did not affect the thymidine-labeling indices or distribution of labeling in colonic epithelium. Selenium may inhibit cell proliferation when it is the result of an unusually intense stimulus. This finding could explain in part the inhibitory effect of Se in some experimental cancer models. Dr. Tempero is a recipient of a Junior Clinical Faculty Fellowship from the American Cancer Society.     

Life cycle and nymphal feeding of Besdolus ravizzarum (Plecoptera: Perlodidae), a threatened stonefly

Abstract We have studied some aspects of Besdolus ravizzarum biology in the Apennines. This stonefly has a very localized distribution in southeastern France and northern Italy. This species is considered threatened. For this reason it is especially relevant to improve knowledge about its natural history, previously unknown. Despite the large size of nymphs, this species shows a univoltine life cycle. The growth is slow but uniform from October to April or May when the short flight period occurs. The analysis of the gut contents indicates this species is a predator, feeding mainly on Baetidae and Chironomidae. It is notable that the development of this carnivorous species through cold periods coincides with the season with higher richness and density of potential prey in Apennine streams. Further studies are needed to improve knowledge of the distribution of the species and to start planning effective conservation efforts.     

Why Did a Female Penis Evolve in a Small Group of Cave Insects?

The evolution of a female penis is an extremely rare event and is only known to have occurred in a tribe of small cave insects, Sensitibillini (Psocodea: Trogiomorpha: Prionoglarididae). The female penis, which is protrudable and inserted into the male vagina‐like cavity during copulation to receive semen, is thought to have evolved independently twice in this tribe, in the Brazilian Neotrogla and the African Afrotrogla. These findings strongly suggest that there are some factors unique to Sensitibillini that have facilitated female penis evolution. Here, several hypothetical factors are presented that may have enabled the evolution of the female penis in Sensitibillini. The female–female competition for nutritious semen, the oligotrophic environment, and the twin insemination slots with switching valve are considered to be the driving factors for female penis evolution. Additionally, the following factors are considered responsible for relaxing the constraint against female penis evolution: preexistence of the female‐above mating position, the elongated duct connecting the female pre‐penis with the sperm storage organ, and the small male genital cavity accepting the female genital tubercle bearing the opening of this duct. Understanding the factors enabling female penis evolution may also shed light on the evolution of the male penis.     

Specific network and phylosymbiosis pattern in endophyte community of coastal halophytes

Halophytes colonize stressed environments of high salinity. Endophytic symbionts improve growth performance and thus adaptability of host plants in stressed environments. Nevertheless, studies focused on the distribution and assembly patterns of fungal endophyte assemblages of halophytes in high salinity environments are limited. We selected 27 common non-mangrove halophytes across 4 geographic sites along the eastern coastline of China for our investigation on endophyte assemblages. We found a significant amount of basidiomycetous fungi in the endophyte assemblage. The endophyte community compositions were significantly affected by plant species and geographic locations. Some halophyte hosts showed significant preference for endophytic fungi in host preference analysis. The network structures of host-microbe bipartite graphs at each site had low connection and were highly nested, modular and specialized. Current results also indicated significant correlation and congruency between host phylogeny and compositions of endophyte local communities and meta-community. Our research showed that host is the dominant factor shaping the fungal endophytic communities in aerial tissues of halophytes in high salinity environments, and the host influence on endophytic community relates to plant phylogeny.     

Computational characterization of proteins

Computational characterization of proteins is a necessary first step in understanding the biologic role of a protein. The composite architecture of mammalian proteins makes the prediction of the biologic role rather difficult. Nevertheless, integration of many different prediction methods allows for a more accurate representation. Information on the 3D structure of a protein improves the reliability of predictions of many features. This article reviews existing methods used to characterize proteins and several tools that provide an integrated access to different types of information. The authors point out the increasing importance of structural constraints and an increasing need to integrate different approaches.     

Predominant female care in the beetle Lethrus apterus with supposedly biparental care

Although intensive care for offspring by both parents is rare in arthropods, it occurs in some species including the beetle Lethrus apterus. According to previous publications, in this species the male collects leaves, which are used by the female to form balls in the underground nest burrow. These balls serve as food for the hatched offspring. Most knowledge about the behavior of this species is based on information collected more than a century ago. Therefore, we investigated above‐ground breeding behavior and the status of nest burrows of this beetle in its natural habitat in Hungary. Our results suggest that contrary to previously documented cases, above‐ground parental care, i.e. the collection of leaves, is done predominantly not by the males but the females. Further research is needed to understand the role of the sexes in parental care in this species and to explain the discrepancy between the previously documented cases and the results we report here.     

Poly-β-hydroxybutyrate metabolism in Azospirillum brasilense and the ecological role of PHB in the rhizosphere

Abstract Azospirillum brasilense is a rhizosphere microorganism which has potential use for promoting plant growth in economically important crops. Its ability to survive the adverse conditions imposed by nutrient starvation and competition in the rhizosphere is of great importance. A. brasilense accumulates up to 70% of its cell dry weight with poly-β-hydroxybutyrate (PHB). In the presence of stress factors such as ultraviolet radiation, desiccation and osmotic stress, PHB-rich cells survived better than PHB-poor cells. Polymer-rich cells of Azospirillum fixed N₂ in the absence of exogenous carbon and combined nitrogen. The enzymes of the PHB cycle in both the synthesis and degradation processes as well as during starvation were more active in PHB-rich cells. After 24 h of starvation there was a peak of activity of d (−)β-hydroxybutyrate dehydrogenase, β-ketothiolase and thiophorase due to PHB degradation. Additionally, acetoacetyl-CoA reductase dropped to a minimum level because PHB could not be synthesized. The possible utilization of PHB as a sole carbon and energy source by A. brasilense and other bacteria during establishment, proliferation and survival in the rhizosphere will be discussed.     

Periodontitis and mechanisms of cardiometabolic risk: Novel insights and future perspectives

Periodontitis is an infectious and inflammatory disease of the tooth-supporting tissues caused by the accumulation of subgingival plaque and the action of specific periodontopathogenic bacteria. Periodontitis has been associated with cardiovascular diseases and considered a cardiovascular risk factor. Several mechanisms have been proposed to explain this association, such as the infection of atherosclerotic plaques by periodontal pathogens, the pro-atherogenic effect on the lipid profile, the systemic dissemination of pro-inflammatory mediators or the contribution to type 2 diabetes mellitus. Periodontal treatment has also been related to improvement in cardiometabolic risk variables, and oral hygiene techniques may be useful in reducing cardiometabolic risk. The aim of this review is to provide new and recent insights on the relationship between periodontitis and cardiometabolic risk, focusing on recent evidence. Comments on shared potential therapeutic targets, such as the role of glucagon-like peptide 1, are also highlighted.     

Studies on phosphate metabolism in obligate methanotrophs

Abstract Studies on three representative species of methane-utilizing bacteria revealed high intracellular levels of inorganic pyrophosphate (5 mM) in contrast to low levels of ATP (0.5 mM) as well as the differences in the sets of enzymes utilizing pyro- and polyphosphates as phosphate and metabolic energy donors.