Tissue distribution and differential expression of melanocortin 1 receptor, a malignant melanoma marker

The melanocortin 1 receptor is a G-protein-coupled receptor, described to be expressed on melanomas and melanocytes. Subsequent RT–PCR studies demonstrated the presence of melanocortin 1 receptor mRNA in other tissues such as pituitary gland and testis. Previously, we have demonstrated that three HLA-A2 binding nonamer peptides derived from melanocortin 1 receptor can elicit peptide-specific CTL which can recognize target cells transfected with the melanocortin 1 receptor gene and MHC class I matched melanoma lines. The potential of targeting melanocortin 1 receptor in therapy and diagnosis will depend on a preferential expression of this receptor in the majority of primary and metastatic melanomas vs normal tissues. We tested a panel of melanomas, carcinomas and other cell lines for the presence of melanocortin 1 receptor, using two monoclonal antibodies. The receptor was detected in 83% of the tested melanoma cell lines but not in other carcinoma lines. Immunohistochemistry revealed a strong expression of melanocortin 1 receptor in all tested primary and metastatic melanomas, but also demonstrated low levels of expression in adrenal medulla, cerebellum, liver and keratinocytes. Flow cytometry studies showed that melanocortin 1 receptor was expressed in in vitro activated monocytes/macrophages and in the THP-1 monocytic leukaemia line at levels of about 1 in 3 to 1 in 5 of that found in melanomas. Peripheral blood-derived dendritic cells, also express melanocortin 1 receptor in vitro. This extensive analysis of melanocortin 1 receptor tissue distribution may be of relevance not only for melanoma immunology, but also for research on the pathogenicity of inflammatory conditions in the skin and neurologic tissues. It remains to be seen if the over-expression of melanocortin 1 receptor in melanomas is sufficiently high to allow a ‘therapeutic window’ to be exploited in cancer immunotherapy

Aging in a Long-Lived Clonal Tree

Using genetic estimates of clone age in trembling aspen, this study demonstrates a significant decline in male sexual fitness with increasing age, showing that long-lived clonal organisms are vulnerable to aging

Mapping Genetic Diversity of Cherimoya (Annona cherimola Mill.): Application of Spatial Analysis for Conservation and Use of Plant Genetic Resources

There is a growing call for inventories that evaluate geographic patterns in diversity of plant genetic resources maintained on farm and in species' natural populations in order to enhance their use and conservation. Such evaluations are relevant for useful tropical and subtropical tree species, as many of these species are still undomesticated, or in incipient stages of domestication and local populations can offer yet-unknown traits of high value to further domestication. For many outcrossing species, such as most trees, inbreeding depression can be an issue, and genetic diversity is important to sustain local production. Diversity is also crucial for species to adapt to environmental changes. This paper explores the possibilities of incorporating molecular marker data into Geographic Information Systems (GIS) to allow visualization and better understanding of spatial patterns of genetic diversity as a key input to optimize conservation and use of plant genetic resources, based on a case study of cherimoya (Annona cherimola Mill.), a Neotropical fruit tree species. We present spatial analyses to (1) improve the understanding of spatial distribution of genetic diversity of cherimoya natural stands and cultivated trees in Ecuador, Bolivia and Peru based on microsatellite molecular markers (SSRs); and (2) formulate optimal conservation strategies by revealing priority areas for in situ conservation, and identifying existing diversity gaps in ex situ collections. We found high levels of allelic richness, locally common alleles and expected heterozygosity in cherimoya's putative centre of origin, southern Ecuador and northern Peru, whereas levels of diversity in southern Peru and especially in Bolivia were significantly lower. The application of GIS on a large microsatellite dataset allows a more detailed prioritization of areas for in situ conservation and targeted collection across the Andean distribution range of cherimoya than previous studies could do, i.e. at province and department level in Ecuador and Peru, respectively

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Acute kidney injury from Paraquat poisoning: a case report.

Paraquat is a salt widely used as a herbicide. Although paraquat poisoning is rare in the general population, it may be considered as one of the most toxic poisons frequently used for suicide attempts, and is associated with serious complications including: acute kidney injury,pneumonitis and death. We report a fatal case of a16 year old girl who presented with dysphagia, cough and dyspnoea following ingestion of paraquat. She subsequently developed acute kidney injury (AKI) that resolved but she succumbed to respiratory complications despite use of antibiotics, corticosteroids and haemodialysis.Key words: Paraquat poisoning, Acute Kidney Injury, Haemodialysis, Pneumonitis

Simulation of reversible polycondensations with monomer having reactivity different from that of higher homologs

Reversible AB-type polycondensations have been simulated in a batch reactor where the monomer reacts with itself or any higher oligomer with a rate constant R times that for higher mers. Similarly, the rate of reaction of the condensation product with an -AB- group at the end of a polymer chain has been assumed to be R' times that with an "internal" --AB-- group. The variation of the number-average chain length μn with time (until equilibrium is reached) has been obtained. μn is found to be lower and the polydispersity index higher in the presence of the reverse reactions. Where the equilibrium conversions are high enough, a split in the molecular-weight distribution (MWD) curves is observed for even- and odd-order homologs for R < 1, though this effect is considerably diminished as compared with that in similar irreversible polycondensations. It is also found that the most probable distribution does not adequately represent the MWD when the functional groups violate the equal-reactivity hypothesis and number-average chain lengths are relatively small

Reversible polycondensation characterized by unequal reactivities of functional groups

Molecular weight distributions and moments for reversible condensation polymerizations with unequal reactivities of functional groups both in the forward and reverse steps, have been obtained. Results are qualitatively similar to those obtained for the corresponding irreversible case, i.e., MWD curves split into two, one for odd-n and one for even values of n for R (= reactivity of monomer with monomer/reactivity of other oligomers) larger than unity. When R is less than one, there is a preponderance of monomer in the reaction mass. However, these effects are considerable reduced due to the reversibility of polymerization. Comparison with Flory's most probable distribution indicates that this function represents the MWDs of the polymer for both irreversible and reversible cases only when the functional groups exhibit equal reactivity. For the unequal reactivity case, such a one-parameter (in terms of functional group conversion) characterization of the MWDs is unlikely