Liposomal temocene (m-THPPo) photodynamic treatment induces cell death by mitochondria-independent apoptosis

Background

The cell death pathway activated after photodynamic therapy (PDT) is controlled by a variety of parameters including the chemical structure of the photosensitizer, its subcellular localization, and the photodynamic damage induced. The present study aims to characterize a suitable m-THPPo liposomal formulation, to determine its subcellular localization in HeLa cells and to establish the cell death mechanisms that are activated after photodynamic treatments.

Methods

Liposomes containing m-THPPo were prepared from a mixture of DPPC and DMPG at a 9:1 molar ratio. In order to procure the best encapsulation efficiency, the m-THPPo/lipid molar ratio was considered. HeLa cells were incubated with liposomal m-THPPo and the subcellular localization of m-THPPo was studied. Several assays such as TUNEL, annexin V/propidium iodide and Hoechst-33258 staining were performed after photodynamic treatments. The apoptotic initiation was assessed by cytochrome c and caspase-2 immunofluorescence.

Results

m-THPPo encapsulated in liposomes showed a decrease of the fluorescence and singlet oxygen quantum yields, compared to those of m-THPPo dissolved in tetrahydrofuran. Liposomal m-THPPo showed colocalization with LysoTracker® and it induced photoinactivation of HeLa cells by an apoptotic mechanism. In apoptotic cells no relocalization of cytochrome c could be detected, but caspase-2 was positive immediately after photosensitizing treatments.

Conclusions

Photodynamic treatment with liposomal m-THPPo leads to a significant percentage of apoptotic morphology of HeLa cells. The activation of caspase-2, without the relocalization of cytochrome c, indicates a mitochondrial-independent apoptotic mechanism.

General significance

These results provide a better understanding of the cell death mechanism induced after liposomal m-THPPo photodynamic treatment.     

Human Dietary Exposure to Uranium in Catalonia, Spain

The purpose of this study was to determine the daily dietary intake of uranium (U) by the general population of Catalonia, Spain. Uranium concentrations were measured in foods widely consumed by the population living in that autonomous community. Food samples were randomly acquired in 12 representative cities of Catalonia. The dietary intake of U was estimated for various age–gender groups: children, adolescents, adults, and seniors. Fish and seafood was the food group showing the highest U concentrations (0.090 μg/g of fresh weight (fw)), followed by dairy products (0.044 μg/g fw). In contrast, the lowest U levels were found in oils and fats (0.003 μg/g fw), while in tubers and milk, U was not detected in any sample. The estimated dietary intake of U for a standard male adult of 70 kg body weight living in Catalonia was 15.48 μg/day. According to the age/gender of the population, the highest dietary intake of U corresponded to children (20.32 μg/day), while senior females was the subgroup with the lowest U intake (10.04 μg/day). Based on the tolerable daily intake established for U, the current dietary intake of this metal by the general population of Catalonia should not mean health risks for any of the different age/gender groups of consumers.     

Role of Central Metabolism in the Osmoadaptation of the Halophilic Bacterium Chromohalobacter salexigens

Bacterial osmoadaptation involves the cytoplasmic accumulation of compatible solutes to counteract extracellular osmolarity. The halophilic and highly halotolerant bacterium Chromohalobacter salexigens is able to grow up to 3 m NaCl in a minimal medium due to the de novo synthesis of ectoines. This is an osmoregulated pathway that burdens central metabolic routes by quantitatively drawing off TCA cycle intermediaries. Consequently, metabolism in C. salexigens has adapted to support this biosynthetic route. Metabolism of C. salexigens is more efficient at high salinity than at low salinity, as reflected by lower glucose consumption, lower metabolite overflow, and higher biomass yield. At low salinity, by-products (mainly gluconate, pyruvate, and acetate) accumulate extracellularly. Using [1-¹³C]-, [2-¹³C]-, [6-¹³C]-, and [U-¹³C₆]glucose as carbon sources, we were able to determine the main central metabolic pathways involved in ectoines biosynthesis from glucose. C. salexigens uses the Entner-Doudoroff pathway rather than the standard glycolytic pathway for glucose catabolism, and anaplerotic activity is high to replenish the TCA cycle with the intermediaries withdrawn for ectoines biosynthesis. Metabolic flux ratios at low and high salinity were similar, revealing a certain metabolic rigidity, probably due to its specialization to support high biosynthetic fluxes and partially explaining why metabolic yields are so highly affected by salinity. This work represents an important contribution to the elucidation of specific metabolic adaptations in compatible solute-accumulating halophilic bacteria.     

Temperature- and Salinity-Decoupled Overproduction of Hydroxyectoine by Chromohalobacter salexigens

Hydroxyectoine overproduction by the natural producer Chromohalobacter salexigens is presented in this study. Genetically engineered strains were constructed that at low salinity coexpressed, in a vector derived from a native plasmid, the ectoine (ectABC) and hydroxyectoine (ectD) genes under the control of the ectA promoter, in a temperature-independent manner. Hydroxyectoine production was further improved by increasing the copies of ectD and using a C. salexigens genetic background unable to synthesize ectoines.     

La participación de personas con demencia en las reuniones del plan de atención individualizada: impacto en el bienestar y la calidad del cuidado

Introduction

An individualised intervention plan (IIP) offers a new paradigm in the care of the elderly with dementia, with the aim of increasing their quality of life through personalisation, respect for their freedom, and their participation in the decisions that affect their lives.

Objective

To evaluate the impact of the residential home patient with dementia and their quality of care when they take part in the interdisciplinary meeting in which their care plan is decided.

Material and methods

A total of 52 elderly patients with dementia took part in the study. They were distributed into two groups, one experimental (37 residents) and another control (15 residents). The Dementia Care Mapping (DCM) tool was used to assess the well-being and quality of care of the residents. This tool was used twice, before and after the intervention.

Results

The well-being of the resident, evaluated using the DCM, was similar before and after the intervention in the experimental group. No differences were observed either on comparing the control and experimental groups. However, some indicators of carer behaviour were different before and after the intervention, and when the control and experimental group were compared.

Conclusion

The inclusion of elderly persons with dementia in their IIP meeting had a positive effect in the interaction of the staff with the residents, but not on the well-being of the resident.     

Pollen morphology in the genus Veronica L. (Plantaginaceae) and its systematic significance

Pollen grains of 30, mainly annual, species from 134 populations of the genus Veronica (Plantaginaceae, formerly Scrophulariaceae) from the Mediterranean Region, have been studied with light and scanning electron microscopy. Three pollen types are defined based on pollen size and exine surface sculpture. In some cases within the study group pollen size can be useful in species determination. Hypothetical relationships of pollen grain size and aperture number with ploidy level, style length and corolla diameter are discussed. The ornamentation of the exine in Veronica, although generally a conservative character within the genus, gives some additional support to the most recent infrageneric classification of Veronica.     

Pollen morphology and systematics of Atripliceae (Chenopodiaceae)

Pollen morphology of 58 species from 17 putative genera of the tribe Atripliceae (Chenopodiaceae) was investigated using light (LM) and scanning electron microscopy (SEM). Morphological variation was analyzed based on a dense sampling of the subtribes Atriplicinae and Eurotiinae, including many of the species in the two largest genera: Atriplex and Obione. The pantoporate pollen grains of Atripliceae are characterized by their spheroidal or subspheroidal shape, flat or moderately vaulted mesoporia with 21–120 pores, tectum with 1–8 spinules and 5–28(?38) puncta per?µm², and 1–13 ectexinous bodies bearing 1–7 spinules each. Taxonomic relevance of the most important pollen morphological characters is discussed (pollen diameter, pore number, pore diameter, interporal distance, spinule and puncta density and ratio, number of ectexinous bodies, and their spinules). Pollen morphological data support the exclusion of Suckleya from the tribe and the recognition of subtribe Eurotiinae, but suggest that it needs to be reviewed. Pollen does not support generic recognition of Atriplex, Neopreissia and Obione and infrageneric subdivisions as currently recognized, and suggests the need to review them. Smaller or monotypic genera, such as Axyris, Ceratocarpus, Endolepis, Krascheninnikovia, Microgynoecium, Proatriplex and Spinacia have distinctive pollen morphological characters that support their generic status. Grayia needs to be reevaluated; although its two species are distinct from all the other species in the study, there are notable differences between each of them, and this suggests they may not form a natural group. Multivariate techniques were employed to investigate if there are discrete patterns of variation within Atripliceae. Principal Component Analyses (PCA) weakly differentiates four groups based on variation in pore number, puncta density per?µm², and ratio between spinule and puncta density per?µm²; species of Ceratocarpus, Haloxanthium, Krascheninnikovia, Manochlamys, Microgynoecium, Spinacia, and some species of Atriplex and Obione are isolated. Preliminary results indicate that pollen data are potentially useful in the classification of the tribe, and further studies will be of taxonomic value.     

Genetics at the verge of extinction: insights from the Iberian lynx

Population viability might become compromised by the loss of genetic diversity and the accumulation of inbreeding resulting from population decline and fragmentation. The Iberian lynx (Lynx pardinus) provides a paradigmatic example of a species at the verge of extinction, and because of the well‐documented and different demographic histories of the two remaining populations (Doñana and Andújar), it provides the opportunity to evaluate the performance of analytical methods commonly applied to recently declined populations. We used mitochondrial sequences and 36 microsatellite markers to evaluate the current genetic status of the species and to assess the genetic signatures of its past history. Mitochondrial diversity was extremely low with only two haplotypes, alternatively fixed in each population. Both remnant populations have low levels of genetic diversity at microsatellite markers, particularly the population from Doñana, and genetic differentiation between the two populations is high. Bayesian coalescent‐based methods suggest an earlier decline starting hundreds of years ago, while heterozygosity excess and M‐ratio tests did not provide conclusive and consistent evidence for recent bottlenecks. Also, a model of gene flow received overwhelming support over a model of pure drift. Results that are in conflict with the known recent demography of the species call for caution in the use of these methods, especially when no information on previous demographic history is available. Overall, our results suggest that current genetic patterns in the Iberian lynx are mainly the result of its recent decline and fragmentation and alerts on possible genetic risks for its persistence. Conservation strategies should explicitly consider this threat and incorporate an integrated genetic management of wild, captive and re‐introduced populations, including genetic restoration through translocations.