Ethical and legal issues in xenotransplantation

In most western countries, there is a 'human organ shortage' with waiting lists for the performance of transplantation. In a recent report of the UNOS Ethics Committee it is stated that there are approximately 31,000 potential recipients on waiting lists, but only one fourth of potential donors gave their specific consent.
Xenotransplantation – defined as the transplantation of animal cells, tissues or organs into human beings – is associated with particular ethical dilemmas, namely the problems of efficiency and safety of this medical procedure. The objective of this study is to analyse the ethical dilemmas in xenotransplantation with the background of a personal view of moral life. Also, xenotransplantation will be evaluated as far as the legal regulation of transplantation is concerned. In particular, we will consider patients rights in accordance with existing laws on organ and tissue transplantation, animal research and clinical trials.     

Bacterial functional redundancy along a soil reclamation gradient

A strategy to measure bacterial functional redundancy was developed and tested with soils collected along a soil reclamation gradient by determining the richness and diversity of bacterial groups capable of in situ growth on selected carbon substrates. Soil cores were collected from four sites along a transect from the Jamari tin mine site in the Jamari National Forest, Rondonia, RO, Brazil: denuded mine spoil, soil from below the canopy of invading pioneer trees, revegetated soil under new growth on the forest edge, and the forest floor of an adjacent preserved forest. Bacterial population responses were analyzed by amending these soil samples with individual carbon substrates in the presence of bromodeoxyuridine (BrdU). BrdU-labeled DNA was then subjected to a 16S-23S rRNA intergenic analysis to depict the actively growing bacteria from each site. The number and diversity of bacterial groups responding to four carbon substrates (L-serine, L-threonine, sodium citrate, and alpha-lactose hydrate) increased along the reclamation-vegetation gradient such that the preserved forest soil samples contained the highest functional redundancy for each substrate. These data suggest that bacterial functional redundancy increases in relation to the regrowth of plant communities and may therefore represent an important aspect of the restoration of soil biological functionality to reclaimed mine spoils. They also suggest that bacterial functional redundancy may be a useful indicator of soil quality and ecosystem functioning.     

Synthesis of vitellogenin by the follicle cells of Rhodnius prolixus

The synthesis and secretion of vitellogenin by the ovary of Rhodnius prolixus was investigated. Using whole ovary or epithelial cells isolated from follicles of different sizes, it is shown that the follicle cells are a site of synthesis for this protein in the ovary. The ovaries or follicle cells were incubated in vitro with [(35)S]-methionine or (32)Pi and the secretion of newly synthesized ovarian vitellogenin (O-Vg) was estimated by the radioactivity associated with the immunoprecipitate or acid-precipitate proteins in the culture medium. The radioactive O-Vg was analyzed by SDS-PAGE followed by autoradiography or after elution from a DEAE-Toyopearl column. The presence of O-Vg inside the follicle cells was detected by immunofluorescence and immunogold labels. Both methods revealed strong labeling inside the follicle cells. While the capacity for total protein synthesis by the follicle cells was maximal during the early phase of vitellogenesis (in small follicles), the synthesis of O-Vg reached its peak during the late phase of oocyte growth, just before formation of the chorion. A possible role for ovarian vitellogenin in Rhodnius and its relationship with Vg synthesis by the fat body is discussed.     

Trehalose delays the reversible but not the irreversible thermal denaturation of cutinase

The effect of trehalose (0.5 M) on the thermal stability of cutinase in the alkaline pH range was studied. The thermal unfolding induced by increasing temperature was analyzed in the absence and in the presence of trehalose according to a two-state model (which assumes that only the folded and unfolded states of cutinase were present). Trehalose delays the reversible unfolding. The midpoint temperature of the unfolding transition (Tm) increases by 4.0 degrees C and 2. 6 degrees C at pH 9.2 and 10.5, respectively, in the presence of trehalose. At pH 9.2 the thermal unfolding occurs at higher temperatures (Tm is 52.6 degrees C compared to 42.0 degrees C at pH 10.5) and a refolding yield of around 80% was obtained upon cooling. This pH value was chosen to study the irreversible inactivation (long-term stability) of cutinase. Temperatures in the transition range from folded to unfolded state were selected and the rate constants of irreversible inactivation determined. Inactivation followed first-order kinetics and trehalose reduced the observed rate constants of inactivation, pointing to a stabilizing effect on the irreversible inactivation step of thermal denaturation. However, if the contribution of reversible unfolding on the irreversible inactivation of cutinase was taken into account, i.e., considering the fraction of cutinase molecules in the reversible unfolded conformation, the intrinsic rate constants can be calculated. Based on the intrinsic rate constants it was concluded that trehalose does not delay the irreversible inactivation. This conclusion was further supported by comparing the activation energy of the irreversible inactivation in the absence and in the presence of trehalose. The apparent activation energy in the absence and in the presence of trehalose were 67 and 99 Kcal/mol, respectively. The activation energy calculated from intrinsic rate constants was higher in the absence (30 Kcal/mol) than in the presence of trehalose (16 Kcal/mol), showing that kinetics of the irreversible inactivation step increased in the presence of trehalose. In fact, trehalose stabilized only the reversible step of thermal denaturation of cutinase.     

Purification and characterisation of vanadium haloperoxidases from the brown alga Pelvetia canaliculata

Two enzymes characterised as iodoperoxidases (PcI and PcII), with vanadium-dependent activity, have been purified from the brown alga Pelvetia canaliculata (L.) Decne et Thur. (Fucaceae, Phaeophyceae), collected in the Northern Portuguese coast, at Viana do Castelo. The relative molecular masses were 166 kDa for PcI and 416 kDa for PcII, as determined by gel filtration. SDS-PAGE shows that PcI has just one band corresponding to a subunit of 66 kDa, while PcII shows four bands (66, 72, 157 and 280 kDa). The following kinetic parameters have been determined from a steady-state analysis of the oxidation of iodide by H2O2: PcI, pHopt = 6.0, KM(I-) = 2.1 mM, KM(H2O2) = 110 microM, Ki(I-) = 127 mM; and PcII, pHopt = 6.5, KM(I-) = 2.4 mM, KM(H2O2) = 20 microM and Ki(I-) = 69 mM. These iodoperoxidases are thermostable, as also observed for vanadium bromo- and chloroperoxidases.     

Radiizonates arcuatus, a distinctive new miospore species from the Lower Carboniferous of Western Gondwana

A new species of trilete zonate miospores, Radiizonates arcuatus, is established for Lower Carboniferous Western Gondwanan forms hitherto ascribed misguidedly to Radiizonates genuinus (Jushko) Loboziak and Alpern (1978), a Russian Lower Carboniferous species. The latter binomen is, moreover, not a valid combination and is more correctly designated as Vallatisporites genuinus (Jushko) Byvsheva, 1980. R. arcuatus is, from records to date, confined to westerly parts of Gondwana (Brazil, North Africa and Middle East), in which it is characteristic of Early Carboniferous strata, albeit with some slightly older and slightly younger occurrences.     

Differential expression of D(1A) and D(1B) dopamine receptor mRNAs in the developing avian retina

In the chick retina, the D1 dopaminergic system differentiates very early, as shown by receptor-mediated increases in intracellular cyclic AMP concentration and the presence of [(3)H]SCH23390-specific binding sites. Here, we characterized, by RT-PCR, the expression of defined D1 receptor subtypes D(1A), D(1B), and D(1D) during the development of the chick retina. Total RNA was extracted from retinas of 6-day-old embryos (E6) to 1-day-old hatched chickens and reverse-transcribed. The resulting cDNA was amplified using D(1A)-, D(1B)-, or D(1D)-specific primers, and the PCR-amplified products were analyzed by electrophoresis. The fragment corresponding to D(1A) receptor was detected in developing retina as early as E7, whereas the fragment corresponding to D(1B) was observed starting around E10. No PCR product corresponding to D(1D) was observed in the retina, although it was detected in chick brain. As synaptogenesis in chick retina begins after E11 and [(3)H]SCH 23390 D1 binding sites increase after this stage, the present results show that expression of D(1B) receptor increases during synaptogenesis, whereas D(1A) is the receptor subtype associated with the D1-like actions of dopamine early in retina development.     

Anti-inflammatory and wound healing potential of cashew apple juice (Anacardium occidentale L.) in mice

Cashew apple is a tropical pseudofruit consumed as juice due to its excellent nutritional and sensory properties. In spite of being well known for its important antioxidant properties, the cashew apple has not been thoroughly investigated for its therapeutic potential. Thereby, this study evaluated the antioxidant capacity, anti-inflammatory, and wound-healing activities of cashew apple juice. Juices from ripe and immature cashew apples were analyzed for antioxidant, anti-inflammatory, and wound-healing properties. Those were evaluated in murine models of xylene-induced ear edema and wound excision. Swiss mice were treated with cashew juice by gavage. Edema thickness was measured and skin lesions were analyzed by planimetry and histology. Both antioxidant content and total antioxidant activity were higher in ripe cashew apple juice (RCAJ) than in unripe cashew apple juice (UNCAJ). The UNCAJ presented the main anti-inflammatory activity by a significant inhibition of ear edema (66.5%) when compared to RCAJ (10%). Moreover, UNCAJ also showed the best result for wound contraction (86.31%) compared to RCAJ (67.54%). Despite of higher antioxidant capacity, RCAJ did not promote better anti-inflammatory, and healing responses, which may be explained by the fact that treatment increased antioxidants level leading to a redox “imbalance” turning down the inflammatory response modulation exerted by reactive oxygen species (ROS). The results suggest that UNCAJ presents a greater therapeutic activity due to a synergistic effect of its phytochemical components, which improve the immunological mechanisms as well as an optimal balance between ROS and antioxidants leading to a better wound healing process.     

Genomic Ancestry,Self-Rated Health and Its Association with Mortality in an Admixed Population: 10 Year Follow-Up of the Bambui-Epigen (Brazil) Cohort Study of Ageing

Background

Self-rated health (SRH) has strong predictive value for mortality in different contexts and cultures, but there is inconsistent evidence on ethnoracial disparities in SRH in Latin America, possibly due to the complexity surrounding ethnoracial self-classification.

Materials/Methods

We used 370,539 Single Nucleotide Polymorphisms (SNPs) to examine the association between individual genomic proportions of African, European and Native American ancestry, and ethnoracial self-classification, with baseline and 10-year SRH trajectories in 1,311 community dwelling older Brazilians. We also examined whether genomic ancestry and ethnoracial self-classification affect the predictive value of SRH for subsequent mortality.

Results

European ancestry predominated among participants, followed by African and Native American (median = 84.0%, 9.6% and 5.3%, respectively); the prevalence of Non-White (Mixed and Black) was 39.8%. Persons at higher levels of African and Native American genomic ancestry, and those self-identified as Non-White, were more likely to report poor health than other groups, even after controlling for socioeconomic conditions and an array of self-reported and objective physical health measures. Increased risks for mortality associated with worse SRH trajectories were strong and remarkably similar (hazard ratio ~3) across all genomic ancestry and ethno-racial groups.

Conclusions

Our results demonstrated for the first time that higher levels of African and Native American genomic ancestry—and the inverse for European ancestry—were strongly correlated with worse SRH in a Latin American admixed population. Both genomic ancestry and ethnoracial self-classification did not modify the strong association between baseline SRH or SRH trajectory, and subsequent mortality.