Gene expression and activity of urea cycle enzymes of rat hepatocytes cold stored up to 120h in University of Wisconsin solution

Urea cycle (UC) is the main pathway of ammonium removal. A deficiency in any of the five classical enzymes of the pathway causes a urea cycle disorder. Hepatocellular transplantation is one of the techniques applicable to treat this disorder. In the present work, we investigated the activities and the relative expression levels of two of the UC enzymes: Carbamyl phosphate synthetase I (CPSI) and ornithine transcarbamylase (OTC), in isolated hepatocytes preserved up to 120 h in University of Wisconsin (UW) solution at 0 degrees C, and during the rewarming of these suspensions. During preservation, CPSI showed differences in mRNA levels respect to time 0, while ornithine transcarbamylase remained unchanged. At the end of the rewarming, CPSI showed values of enzymatic activity and relative mRNA level comparable with the control, meanwhile, there was an increment in OTC activity. In line with these results, we found that hepatocytes cold preserved up to 120h in UW solution maintained their ability to remove an ammonium load comparable to freshly isolated hepatocytes. These data indicated that our preservation conditions up to 120h in UW solution followed by rewarming, preserves UC enzymes at levels similar to freshly isolated hepatocytes, allowing the use of these cells in bioartificial liver devices or hepatocellular transplantation.     

Color and genomic ancestry in Brazilians: a study with forensic microsatellites

The population of Brazil, formed by extensive admixture between Amerindians, Europeans and Africans, is one of the most variable in the world. We have recently published a study that used ancestry-informative markers to conclude that in Brazil, at an individual level, color, as determined by physical evaluation, was a poor predictor of genomic ancestry, estimated by molecular markers. To corroborate these findings we undertook the present investigation based on data from 12 commercially available forensic microsatellites that were utilized to estimate the personal genomic origin for each of 752 individuals from the city of S?o Paulo, belonging to different Brazilian color categories (275 Whites, 192 Intermediates and 285 Blacks). The genotypes permitted the calculation of a personal likelihood-ratio estimator of African or European ancestry. Although the 12 marker set proved capable of discriminating between European and African individuals, we observed very significant overlaps among the three color categories of Brazilians. This was confirmed quantitatively using a Bayesian analysis of population structure that did not demonstrate significant genetic differentiation between the three color groups. These results corroborate and validate our previous conclusions using ancestry-informative markers that in Brazil at the individual level there is significant dissociation of color and genomic ancestry.     

5-S-Cysteinyl-dopamine effect on the human dopaminergic neuroblastoma cell line SH-SY5Y

In recent years a catechol-thioether metabolite of dopamine, 5-S-cysteinyl-dopamine, has been identified in certain dopaminergic regions of the brain, notably the Substantia Nigra. 5-S-Cysteinyl-dopamine has received great attention in view of its possible significance as an index of oxidative stress in aging and in neurodegenerative processes, particularly in Parkinson's disease. In the present study the effect of 5-S-cysteinyl-dopamine on human dopaminergic neuroblastoma SH-SY5Y cells is investigated. The substance is highly cytotoxic, even at a concentration as low as 30 microM. Treatment of the cells with 5-S-cysteinyl-dopamine induce the following intracellular responses: a decrease of the mitochondrial transmembrane potential, an increase in reactive oxygen species such as superoxide anion and peroxides, a marked decrease of reduced glutathione and an inhibition of the complex I activity. Caspase-3-like protease activation and oligonucleosomal DNA fragmentation have also been observed. These data are indicative of the onset of apoptotic processes due to 5-S-cysteinyl-dopamine.     

Apoptotic and proliferating hepatocytes differ in prothymosin α expression and cell localization

Prothymosin α is an acidic protein, reported to be involved in cell proliferation and apoptosis, although its precise function in both processes are still unknown. Due to the importance of these processes in the pathogenesis of hepatic diseases and the need to understand the molecular mechanisms underlying these diseases we aimed to investigate the behavior of this protein in liver growth and apoptosis, in two models of hepatocytes in culture. Prothymosin α expression varied throughout the hepatocyte cell cycle, according to its progression. Proliferating hepatocytes showed increased expression of the protein, while apoptotic ones showed decreased levels. The subcellular location of prothymosin α differed according to the different phases of the cell cycle. Thus, it appeared with a stippled and widely dispersed pattern throughout the nucleus in quiescent and proliferating hepatocytes, while it became cytoplasmic in mitotic and late apoptotic cells. These results are in agreement with the idea that high levels of prothymosin α need to be present in the nucleus for proliferation, and programmed cell death requires low levels of prothymosin α outside of the nucleus. The differences in prothymosin α expression and localization during hepatocyte proliferation and apoptosis suggest that this protein may have a pleiotropic function that depends not only on its availability but also on its various localizations in different subcellular compartments.     

Interactive properties of human glioblastoma cells with brain neurons in culture and neuronal modulation of glial laminin organization

The harmonious development of the central nervous system depends on the interactions of the neuronal and glial cells. Extracellular matrix elements play important roles in these interactions, especially laminin produced by astrocytes, which has been shown to be a good substrate for neuron growth and axonal guidance. Glioblastomas are the most common subtypes of primary brain tumors and may be astrocytes in origin. As normal laminin-producing glial cells are the preferential substrate for neurons, and glial tumors have been shown to produce laminin, we questioned whether glioblastoma retained the same normal glial-neuron interactive properties with respect to neuronal growth and differentiation. Then, rat neurons were co-cultured onto rat normal astrocytes or onto three human glioblastoma cell lines obtained from neurosurgery. The co-culture confirmed that human glioblastoma cells as well as astrocytes maintained the ability to support neuritogenesis, but non-neural normal or tumoral cells failed to do so. However, glioblastoma cells did not distinguish embryonic from post-natal neurons in relation to neurite pattern in the co-cultures, as normal astrocytes did. Further, the laminin organization on both normal and tumoral glial cells was altered from a filamentous arrangement to a mixed punctuate/filamentous pattern when in co-culture with neurons. Together, these results suggest that glioblastoma cells could identify neuronal cells as partners, to support their growth and induce complex neurites, but they lost the normal glia property to distinguish neuronal age. In addition, our results show for the first time that neurons modulate the organization of astrocytes and glioblastoma laminin on the extracellular matrix.     

Genetic structure of wild and cultivated olives in the central Mediterranean basin

BACKGROUND AND AIMS: Olive cultivars and their wild relatives (oleasters) represent two botanical varieties of Olea europaea subsp. europaea (respectively europaea and sylvestris). Olive cultivars have undergone human selection and their area of diffusion overlaps that of oleasters. Populations of genuine wild olives seem restricted to isolated areas of Mediterranean forests, while most other wild-looking forms of olive may include feral forms that escaped cultivation. METHODS: The genetic structure of wild and cultivated olive tree populations was evaluated by amplified fragment length polymorphism (AFLP) markers at a microscale level in one continental and two insular Italian regions. KEY RESULTS: The observed patterns of genetic variation were able to distinguish wild from cultivated populations and continental from insular regions. Island oleasters were highly similar to each other and were clearly distinguishable from those of continental regions. Ancient cultivated material from one island clustered with the wild plants, while the old plants from the continental region clustered with the cultivated group. CONCLUSIONS: On the basis of these results, we can assume that olive trees have undergone a different selection/domestication process in the insular and mainland regions. The degree of differentiation between oleasters and cultivated trees on the islands suggests that all cultivars have been introduced into these regions from the outside, while the Umbrian cultivars have originated either by selection from local oleasters or by direct introduction from other regions.     

Gelatinases, endonuclease and Vascular Endothelial Growth Factor during development and regression of swine luteal tissue

Background  

Zebrafish (D. rerio) has become a powerful and widely used model system for the analysis of vertebrate embryogenesis and organ development. While genetic methods are readily available in zebrafish, protocols for two dimensional (2D) gel electrophoresis and proteomics have yet to be developed.     

Spatial distribution of Oncometopiafacialis (Signoret) (Hemiptera: Cicadellidae) in citrus orchard

The spatial distribution of Oncometopia facialis (Signoret) was studied in sweet orange to elaborate sampling plans and decision-making procedure for the control of this sharpshooter in the field. The samplings were carried out fortnightly in a grid design disposition of 100 points (plants) in citrus orchard, with yellow sticky traps. The average number of O. facialis ranged from 0.35 to 1.17 insects/trap, with the I index varying from 0.89 to 1.82. The fit tests to negative binomial, Poisson distribution, I index and Morisita index indicated aggregated distribution of this insect. The b result of Taylor's power law was 1.6382 (t = 2.71; d.f. = 11; P < 0.05). Sampling plans were elaborated with a precision level of 10, 20 and 25% of error in the mean estimation.     

Survey of ants (Hymenoptera: Formicidae) in the urban area of Uberlândia, MG, Brazil

Uberlandia, MG, Brazil, underwent an accelerated process of urbanization with a population growth of 3,54% each year, higher than the national average. One of the problems emergent from urbanization is the use of different habitats for a great variety of insects. The objective of this study was to identify species of house-invading ants that occur in the urban area of Uberlandia. The occurrence of the house-invading species in regard to the time of urbanization, neighborhood infrastructure, age and maintenance of private houses was also assessed. The ants were collected using bait-traps in 120 residences from 12 neighborhoods which were put in three groups. Fourteen species of ants were catalogued, with Camponotus (Mayr), Monomorium (Mayr) and Tapinoma (Foerster) being the most frequent genera. Only Camponotus vittatus (Forel), Monomorium pharaonis (L.), Tapinoma melanocephalum (Fabricius) and Brachymyrmex sp. (Mayr) were collected in all three groups. The relation between the ants collected and the age and maintenance of the private houses showed that Paratrechina longicornis (Latreille) was most frequent (60%) in poorly preserved or precarious constructions. Whereas, C. vittatus and Camonotus melanoticus (Emery) occurred in all categories of maintenance. Overall, C. vittatus which had not been found in any previously published survey of urban ants, was the most frequent species in urban areas of the Cerrado.