Localisation of aphidicolin-induced break points in Holstein-Friesian cattle (Bos taurus) using RBG-banding

Fragile sites (FS) seem to play a role in genome instability and may be involved in karyotype evolution and chromosome aberrations. The majority of common fragile sites are induced by aphidicolin. Aphidicolin was used at two different concentrations (0.15 and 0.30 μM) to study the occurrence of FS in the cattle karyotype. In this paper, a map of aphidicolin induced break points and fragile sites in cattle chromosomes was constructed. The statistical analysis indicated that any band with three or more breaks was significantly damaged (P < 0.05). According to this result, 30 of the 72 different break points observed were scored as fragile sites. The Pearson correlation test showed a positive association between chromosome length and the number of fragile sites (r = 0.54). On the contrary, 21 FS were identified on negative R bands while 9 FS were located on positive R bands.     

Decreased frequency and activated phenotype of blood CD27 IgD IgM B lymphocytes is a permanent abnormality in systemic lupus erythematosus patients

Introduction  

Systemic lupus erythematosus (SLE) is characterized by B cell hyper-activation and auto-reactivity resulting in pathogenic auto-antibody generation. The phenotypic analysis of blood B cell subsets can be used to understand these alterations.     

The Santa Pola saltern as a model for studying the microbiota of hypersaline environments

Multi-pond salterns constitute an excellent model for the study of the microbial diversity and ecology of hypersaline environments, showing a wide range of salt concentrations, from seawater to salt saturation. Accumulated studies on the Santa Pola (Alicante, Spain) multi-pond solar saltern during the last 35 years include culture-dependent and culture-independent molecular methods and metagenomics more recently. These approaches have permitted to determine in depth the microbial diversity of the ponds with intermediate salinities (from 10 % salts) up to salt saturation, with haloarchaea and bacteria as the two main dominant groups. In this review, we describe the main results obtained using the different methodologies, the most relevant contributions for understanding the ecology of these extreme environments and the future perspectives for such studies.     

Effects of self-fertilization on growth and survival of larvae and juveniles of the scallop Argopecten purpuratus L.

Argopecten purpuratus Lamarck (1819) is a functional hermaphrodite that releases successively male and female gametes during their spawning process. Because the short period between the release of both kind of gametes, the chance of self-fertilization exists, even in natural conditions. The self-fertilization rate was quantified in 10 scallops as the proportion of spontaneous (nonartificially fertilized) cleaving eggs. The existence of inbreeding depression was tested comparing families produced by self- and cross-fertilization. An average of 9.9% of spontaneous self-fertilization was detected. No differences in survival or growth in either larvae or juvenile were found between families produced by self-fertilization and pair mating.     

Early Events in Lymphocyte Transformation by Phytohaemagglutinin

Synthesis and phosphorylation of three main nuclear protein fractions were studied in human lymphocytes stimulated by phytohaemagglutinin (PHA). The first fraction to be synthesized and phosphorylated after induction was that of the acidic proteins, followed by that containing the soluble proteins. Synthesis of histories commenced 24 h after exposure to PHA. Distinctive patterns of both synthesis and phosphorylation of the acidic proteins were recorded at different times in the cell cycle, which may reflect activation or suppression of specific cellular functions. Phosphorylation of the histones also occurred, as an early event during lymphocyte transformation and also much later, at the time of DNA synthesis.     

Evaluation of acetylcholinesterase and adenosine deaminase activities in brain and erythrocytes and proinflammatory cytokine levels in rats submitted to neonatal hypoxia-ischemia model

Perinatal hypoxic-ischemic (HI) brain injury is a common problem with severe neurologic sequelae. The definitive brain injury is a consequence of pathophysiological mechanisms that begin at the moment of HI insult and may extend for days or weeks. In this context, the inflammatory response and the formation of reactive oxygen species seem to play a key role during evolution of brain damage after injury. Thus, the aim of this study was to describe the chronological sequence of acetylcholinesterase (AChE) activity and the lipid peroxidation changes in the cerebral cortex using the classic model of neonatal HI. Furthermore, the erythrocyte AChE and adenosine deaminase (ADA) activities as well as the serum levels of proinflammatory cytokines were assessed. We observed that neonatal HI caused an increase of lipid peroxidation immediately after HI insult, which remained for several days afterward. There was a time-related change in the AChE activity in the cerebral cortex and the same was observed in erythrocyte AChE and ADA activities. In addition, immediately after HI, ADA activity showed a strong positive correlation with all proinflammatory cytokines assessed. Together, these findings may help the understanding of some mechanism related to the pathophysiology of neonatal HI, therefore highlighting the putative therapeutic targets to minimize brain injury and enhance recovery.     

Phototrophic Community in Gypsum Crust from the Atacama Desert Studied by Raman Spectroscopy and Microscopic Imaging

The hyperarid core of the Atacama Desert represents one of the driest places on Earth with an exceptional occurrence of microbial life coping with extreme environmental stress factors. The gypsum crusts have already been found to harbor diverse communities in this area. Here, we present a Raman spectroscopic study, complemented by correlative microscopic imaging using SEM-BSE and fluorescence microscopy, of the endolithic microbial communities inside the Ca-sulphate crusts dominated by phototrophic microorganisms. Differences of pigment composition within different zones follow the cyanobacterial and algal colonization and also reveal the degradation of phycobiliproteins within the decayed biomass of cyanobacteria. Carotenoids of at least three different types were recognized, differing in dependence on the particular phylum of phototrophic microorganisms. Moreover, calcium oxalate monohydrate – whewellite – was found to be associated with the algae and hyphal associations living in the lower regions of the crust. The 785 nm excitation wavelength employed here was found to be the correct source for studying pigment composition as well as for the detection of the oxalate. A comparison of these results with those using 514.5 nm laser excitation which is widely adopted for the detection of carotenoids due to the resonance Raman effect is made and discussed.     

Electrochemical aptamer-based sensors

The valuable properties of aptamers, such as specificity, sensitivity, stability, cost-effectiveness and design flexibility, have favoured their use as biorecognition elements in biosensor development. These synthetic affinity probes can be developed for almost any target molecule, covering a wide range of applications in fields such as clinical diagnosis and therapy, environmental monitoring and food control. The combination of aptamers with high-performance electrochemical transducers, with their inherent high sensitivities, fast response times and simple equipment, has already provided several electrochemical aptamer-based sensors. Moreover, the small size and versatility of aptamers allow efficient immobilisations in high-density monolayers, an important feature towards miniaturisation and integration of compact electrochemical devices. This review describes the state-of-the-art of electrochemical aptamer-based sensors, entering into the details of the different strategies and types of electrochemical transduction and also considering their advantages when applied to the analysis of complex matrices.