A fresh look at the evolution and diversification of photochemical reaction centers

In this review, I reexamine the origin and diversification of photochemical reaction centers based on the known phylogenetic relations of the core subunits, and with the aid of sequence and structural alignments. I show, for example, that the protein folds at the C-terminus of the D1 and D2 subunits of Photosystem II, which are essential for the coordination of the water-oxidizing complex, were already in place in the most ancestral Type II reaction center subunit. I then evaluate the evolution of reaction centers in the context of the rise and expansion of the different groups of bacteria based on recent large-scale phylogenetic analyses. I find that the Heliobacteriaceae family of Firmicutes appears to be the earliest branching of the known groups of phototrophic bacteria; however, the origin of photochemical reaction centers and chlorophyll synthesis cannot be placed in this group. Moreover, it becomes evident that the Acidobacteria and the Proteobacteria shared a more recent common phototrophic ancestor, and this is also likely for the Chloroflexi and the Cyanobacteria. Finally, I argue that the discrepancies among the phylogenies of the reaction center proteins, chlorophyll synthesis enzymes, and the species tree of bacteria are best explained if both types of photochemical reaction centers evolved before the diversification of the known phyla of phototrophic bacteria. The primordial phototrophic ancestor must have had both Type I and Type II reaction centers

Characteristics and outcomes of patients with advanced non-small-cell lung cancer who declined to participate in randomised clinical chemotherapy trials

There are inadequate data on the outcomes of patients who declined to participate in randomised clinical trials as compared with those of participants. We retrospectively reviewed the patient characteristics and treatment outcomes of both participants and non-participants in the two randomised trials for chemotherapy-naive advanced non-small-cell lung cancer. Trial 1 compared four platinum-based combination regimens. Trial 2 compared two sequences of carboplatin plus paclitaxel and gefitinib therapies. Nineteen of 119 (16%) and 153 (37%) patients declined to participate in Trials 1 and 2, respectively. Among the background patient characteristics, the only variable associated with trial participation or declining was the patients' attending physicians (P<0.001). Important differences were not observed in the clinical outcomes between participants and non-participants, for whom the response rates were 30.6 vs 34.2% and the median survival times were 489 vs 461 days, respectively. The hazard ratio for overall survival, adjusted for other confounding variables, was 0.965 (95% confidence interval: 0.73–1.28). In conclusion, there was no evidence to suggest any difference in the characteristics and clinical outcomes between participants and non-participants. Trial designs and the doctor–patient relationship may have an impact on the patient accrual to randomised trials

Terrestrial invasion of pomatiopsid gastropods in the heavy-snow region of the Japanese Archipelago

<p>Abstract</p> <p>Background</p> <p>Gastropod mollusks are one of the most successful animals that have diversified in the fully terrestrial habitat. They have evolved terrestrial taxa in more than nine lineages, most of which originated during the Paleozoic or Mesozoic. The rissooidean gastropod family Pomatiopsidae is one of the few groups that have evolved fully terrestrial taxa during the late Cenozoic. The pomatiopsine diversity is particularly high in the Japanese Archipelago and the terrestrial taxa occur only in this region. In this study, we conducted thorough samplings of Japanese pomatiopsid species and performed molecular phylogenetic analyses to explore the patterns of diversification and terrestrial invasion.</p> <p>Results</p> <p>Molecular phylogenetic analyses revealed that Japanese Pomatiopsinae derived from multiple colonization of the Eurasian Continent and that subsequent habitat shifts from aquatic to terrestrial life occurred at least twice within two Japanese endemic lineages. Each lineage comprises amphibious and terrestrial species, both of which are confined to the mountains in heavy-snow regions facing the Japan Sea. The estimated divergence time suggested that diversification of these terrestrial lineages started in the Late Miocene, when active orogenesis of the Japanese landmass and establishment of snowy conditions began.</p> <p>Conclusions</p> <p>The terrestrial invasion of Japanese Pomatiopsinae occurred at least twice beside the mountain streamlets of heavy-snow regions, which is considered the first case of this event in the area. Because snow coverage maintains stable temperatures and high humidity on the ground surface, heavy-snow conditions may have paved the way for these organisms from freshwater to land via mountain streamlets by preventing winter desiccation in mountain valleys. The fact that the terrestrialization of Pomatiopsidae occurred only in year-round wet environments, but not in seasonally dried regions, provides new insight into ancient molluscan terrestrialization.</p

Delivering anthocyanins in the gastrointestinal tract: processing conditions and food matrix effect

Over the last decade, many studies have demonstrated the potential benefits of using anthocyanins (ACs) in the prevention of metabolic syndrome. Nevertheless, most of these studies have only considered ACs as pure compounds rather than ingredients of bioactive-enriched foods. However, the AC -food matrix interaction could deeply impact on its digestibility and bioaccessibility, and hence, effectiveness. The objective of this study was to evaluate the effectiveness of different dairy and egg-based matrices on the delivering of ACs in the gastrointestinal tract under physiological relevant conditions. Two foods per matrix –milkshake and cream dessert for dairy matrices, and omelet and pancake for egg-based matrices – were produced under industrial conditions and fortified using a highly enriched AC powder obtained from red grapes (Vitis vinifera). After assessing the AC content in the foods by RP- HPLC and pH differential method, simulated gastro-intestinal digestions were carried out following the guidelines developed by INFOGEST (COST action FA 1005). This physiologically relevant model comprises an oral, gastric and intestinal phases, and takes into account many physiological factors. AC present in the soluble fraction at the end of the gastrointestinal digestion was quantified and bioaccessibility % of AC calculated for each food. The heat treatment applied during omelet and pancake production degraded around half of the AC added (47.39 and 58.58% of recovery respectively). However these products presented the best bioaccessibility values after in vitro digestion (44,14 and 40,91%). The solid texture of omelet and pancake could have protected AC from their degradation during the in vitro digestion process. In the non-cooked products, the low bioaccessibility values of AC observed after digestion (36,76% for milkshake and 15,83% for dessert) was compensated with the no losses of AC during its production. Although more experiments have to be done, it seems that non- cooked solid foods are the best option to maximize the delivering of AC in the gastrointestinal tract

Delivering anthocyanins in the gastrointestinal tract: processing conditions and food matrix effect

Over the last decade, many studies have demonstrated the potential benefits of using anthocyanins (ACs) in the prevention of metabolic syndrome. Nevertheless, most of these studies have only considered ACs as pure compounds rather than ingredients of bioactive-enriched foods. However, the AC -food matrix interaction could deeply impact on its digestibility and bioaccessibility, and hence, effectiveness. The objective of this study was to evaluate the effectiveness of different dairy and egg-based matrices on the delivering of ACs in the gastrointestinal tract under physiological relevant conditions. Two foods per matrix –milkshake and cream dessert for dairy matrices, and omelet and pancake for egg-based matrices – were produced under industrial conditions and fortified using a highly enriched AC powder obtained from red grapes (Vitis vinifera). After assessing the AC content in the foods by RP- HPLC and pH differential method, simulated gastro-intestinal digestions were carried out following the guidelines developed by INFOGEST (COST action FA 1005). This physiologically relevant model comprises an oral, gastric and intestinal phases, and takes into account many physiological factors. AC present in the soluble fraction at the end of the gastrointestinal digestion was quantified and bioaccessibility % of AC calculated for each food. The heat treatment applied during omelet and pancake production degraded around half of the AC added (47.39 and 58.58% of recovery respectively). However these products presented the best bioaccessibility values after in vitro digestion (44,14 and 40,91%). The solid texture of omelet and pancake could have protected AC from their degradation during the in vitro digestion process. In the non-cooked products, the low bioaccessibility values of AC observed after digestion (36,76% for milkshake and 15,83% for dessert) was compensated with the no losses of AC during its production. Although more experiments have to be done, it seems that non- cooked solid foods are the best option to maximize the delivering of AC in the gastrointestinal tract