Short-Term Functional and Morphological Changes in the Primary Cultures of Trigeminal Ganglion Cells

Several studies have proved that glial cells, as well as neurons, play a role in pain pathophysiology. Most of these studies have focused on the contribution of central glial cells (e.g., microglia and astrocytes) to neuropathic pain. Likewise, some works have suggested that peripheral glial cells, particularly satellite glial cells (SGCs), and the crosstalk between these cells and the sensory neurons located in the peripheral ganglia, play a role in the phenomenon that leads to pain. Nonetheless, the study of SGCs may be challenging, as the validity of studying those cells in vitro is still controversial. In this study, a research protocol was developed to examine the potential use of primary mixed neuronal–glia cell cultures obtained from the trigeminal ganglion cells (TGCs) of neonate mice (P10–P12). Primary cultures were established and analyzed at 4 h, 24 h, and 48 h. To this purpose, phase contrast microscopy, immunocytochemistry with antibodies against anti-βIII-tubulin and Sk3, scanning electron microscopy, and time-lapse photography were used. The results indicated the presence of morphological changes in the cultured SGCs obtained from the TGCs. The SGCs exhibited a close relationship with neurons. They presented a round shape in the first 4 h, and a more fusiform shape at 24 h and 48 h of culture. On the other hand, neurons changed from a round shape to a more ramified shape from 4 h to 48 h. Intriguingly, the expression of SK3, a marker of the SGCs, was high in all samples at 4 h, with some cells double-staining for SK3 and βIII-tubulin. The expression of SK3 decreased at 24 h and increased again at 48 h in vitro. These results confirm the high plasticity that the SGCs may acquire in vitro. In this scenario, the authors hypothesize that, at 4 h, a group of the analyzed cells remained undifferentiated and, therefore, were double-stained for SK3 and βIII-tubulin. After 24 h, these cells started to differentiate into SCGs, which was clearer at 48 h in the culture. Mixed neuronal–glial TGC cultures might be implemented as a platform to study the plasticity and crosstalk between primary sensory neurons and SGCs, as well as its implications in the development of chronic orofacial pain.     

RNAspa: a shortest path approach for comparative prediction of the secondary structure of ncRNA molecules

Background  

In recent years, RNA molecules that are not translated into proteins (ncRNAs) have drawn a great deal of attention, as they were shown to be involved in many cellular functions. One of the most important computational problems regarding ncRNA is to predict the secondary structure of a molecule from its sequence. In particular, we attempted to predict the secondary structure for a set of unaligned ncRNA molecules that are taken from the same family, and thus presumably have a similar structure.     

Rediscovery of Leptopanchax splendens (Cyprinodontiformes: Aplocheilidae): a seasonal killifish from the Atlantic Forest of south-eastern Brazil that was recently considered extinct

A recent collection of the seasonal killifish found Leptopanchax splendens c. 5 km from the type locality, 74 years after its last record. The species was historically common in its type locality, the Estrela River basin in south-eastern Brazil, until 1950, after which it was not encountered and thought to have become extinct due to widespread deforestation and urbanization in the region. Despite the rediscovery, this study finds that other recently published reports of L. splendens are misidentifications.     

Comparative gene expression study to identify genes possibly related to storage root formation in cassava

Cassava storage roots result from swelling of adventitious roots by secondary growth. In the present study we aimed to gain insight into the molecular processes occurring during cassava storage root formation. We report a comparative gene expression study in adventitious and storage roots in order to identify genes possibly related to storage organ formation. Our results revealed five genes with higher expression levels in secondary xylem of storage roots than adventitious roots. Among them, the Mec1 gene coding for Pt2L4 glutamic acid-rich protein and a putative RING Zinc Finger and LEA protein genes were strongly induced in secondary xylem tissue.     

Dermatan sulfate is the predominant antithrombotic glycosaminoglycan in vessel walls: implications for a possible physiological function of heparin cofactor II

The role of different glycosaminoglycan species from the vessel walls as physiological antithrombotic agents remains controversial. To further investigate this aspect we extracted glycosaminoglycans from human thoracic aorta and saphenous vein. The different species were highly purified and their anticoagulant and antithrombotic activities tested by in vitro and in vivo assays. We observed that dermatan sulfate is the major anticoagulant and antithrombotic among the vessel wall glycosaminoglycans while the bulk of heparan sulfate is a poorly sulfated glycosaminoglycan, devoid of anticoagulant and antithrombotic activities. Minor amounts of particular a heparan sulfate (< 5% of the total arterial glycosaminoglycans) with high anticoagulant activity were also observed, as assessed by its retention on an antithrombin-affinity column. Possibly, this anticoagulant heparan sulfate originates from the endothelial cells and may exert a significant physiological role due to its location in the interface between the vessel wall and the blood. In view of these results we discuss a possible balance between the two glycosaminoglycan-dependent anticoagulant pathways present in the vascular wall. One is based on antithrombin activation by the heparan sulfate expressed by the endothelial cells. The other, which may assume special relevance after vascular endothelial injury, is based on heparin cofactor II activation by the dermatan sulfate proteoglycans synthesized by cells from the subendothelial layer.     

Effects of limited aeration and of the ArcAB system on intermediary pyruvate catabolism in Escherichia coli

The capacity of Escherichia coli to adapt its catabolism to prevailing redox conditions resides mainly in three catabolic branch points involving (i) pyruvate formate-lyase (PFL) and the pyruvate dehydrogenase complex (PDHc), (ii) the exclusively fermentative enzymes and those of the Krebs cycle, and (iii) the alternative terminal cytochrome bd and cytochrome bo oxidases. A quantitative analysis of the relative catabolic fluxes through these pathways is presented for steady-state glucose-limited chemostat cultures with controlled oxygen availability ranging from full aerobiosis to complete anaerobiosis. Remarkably, PFL contributed significantly to the catabolic flux under microaerobic conditions and was found to be active simultaneously with PDHc and cytochrome bd oxidase-dependent respiration. The synthesis of PFL and cytochrome bd oxidase was found to be maximal in the lower microaerobic range but not in a delta ArcA mutant, and we conclude that the Arc system is more active with respect to regulation of these two positively regulated operons during microaerobiosis than during anaerobiosis.     

Ecophysiology of selected tree species in different plant communities at the periphery of the Atlantic Forest of SE Brazil I. Performance of three different species of Clusia in an array of plant communities

Three species of Clusia, namely two CAM-species (C. hilariana Schlecht. and C. fluminensis Planch. et Triana) and a C₃-species (C. parviflora Saldanha et Engl.) were studied in different plant communities at the periphery of the Atlantic Forest in the state of Rio de Janeiro, Brazil. The sites chosen were an inselberg (C. parviflora), a range of wet restinga – dry restinga – semideciduous dry forest (C. fluminensis), and a gradient from the sea shore inland with a first sand dune beach ridge – a dry forest – a second beach ridge (C. hilariana). Analyses comprised C and N contents, soluble carbohydrates, soluble nonprotein N compounds and carbon isotope ratios (¹³C) in leaves, roots, phloem and wood. Photosynthetic performance was assessed by chlorophyll fluorescence with measurements of instant photosynthetic yield as well as light dependence and potential quantum-use efficiency of photosystem II.The data allow, first, to discuss differences between the ecophysiological performance of C₃- and CAM-species of Clusia. The C₃-species, C. parvifolia, had an overall weaker performance than the two CAM-species, where, however, the effects of mode of photosynthesis may have been overlaid by site conditions. Second, it was studied whether ecophysiological performance relates to patterns of local abundance, which was confirmed by showing that the dominant Clusia species of the restingas, C. hilariana, showed the strongest performance overall.Finally, it was studied whether the ecophysiological performance varied in response to site-dependent gradients of environmental water relations, which was confirmed for functions such as photosynthetic capacity, photoinhibition and solute accumulation of C. hilariana and C. fluminensis in relation to moisture of sites.     

Model to evaluate the toxic effect of drugs: vincristine effect in the mass of organs and in the distribution of radiopharmaceuticals in mice

There are evidences that the biodistribution of radiopharmaceuticals can be modified by some drugs. As chemotherapeutic drugs present important toxic effects, we studied the vincristine effect in the mass of organs and are trying to develop a model to evaluate the action of chemotherapeutic drug using the biodistribution of radiopharmaceuticals. Vincristine was administered (n=15) into female Balb/c mice, the organs isolated and their mass determined. To study the vincristine effect in the biodistribution of technetium-99m-dimercaptosuccinic acid (99mTc-DMSA) or technetium-99m-diethylenetriaminepentaacetic acid (99mTc-DTPA), vincristine (0.03 mg) was administered in the animals (n=15) in three doses. 99mTc-DMSA or 99mTc-DTPA was injected 1h after the last dose. After 0.5h, the animals were sacrificed and the percentage of radioactivity (%ATI) and the percentage of radioactivity per gram of tissue (%ATI/g) in each organ were calculated. The results have shown that the mass decreased significantly (Wilcoxon test, P<0.05) in thymus, spleen, ovary, uterus, kidneys, pancreas. The %ATI to 99mTc-DMSA increased in lung, pancreas, heart, thyroid, brain, and bone, and the %ATI/g increased in uterus, ovary, spleen, thymus, kidney, lung, liver, pancreas, heart, thyroid, brain and bone. To 99mTc-DTPA, the %ATI increased in uterus, ovary, spleen, thymus, kidney, lung, liver, stomach, heart and bone, and the %ATI/g increased in uterus, ovary, spleen, thymus, kidney, lung, liver, stomach, heart and bone. The results were statistically significant (Wilcoxon test). The results can be explained by the metabolization, therapeutic, toxicological or immunosupressive action of the vincristine. This model, probably, should be used to evaluate the toxic effect of various drugs.     

Effect of an implant containing the GnRH agonist deslorelin on secretion of LH, ovarian activity and milk yield of postpartum dairy cows

Prevention of high plasma progesterone concentrations in the early postpartum period may improve fertility. Our objective was to determine whether a Deslorelin implant (DESL; 2100 microg, s.c.) would reduce secretion of LH and alter follicle dynamics, plasma concentrations of progesterone, estradiol and PGF2alpha metabolite (PGFM) in postpartum dairy cows. Cows received DESL on Day 7 postpartum (Day 7, n=8) or were untreated (Control, n=9). All cows were injected with GnRH (100 microg, i.m.) on Day 14 to assess LH response. A protocol for synchronization of ovulation with timed AI was initiated on Day 60 (GnRH [Day 60], CIDR [Day 60 to Day 67], PGF2alpha [Day 67, 25 mg and Day 68, 15 mg], GnRH [Day 69] , AI [Day 70]). The LH response to injection of GnRH on Day 14 was blocked in animals treated with DESL. Numbers of Class 1 (<6 mm) follicles were unaffected (P > 0.05) whereas numbers of Class 2 (6 to 9 mm) (P < 0.01) and Class 3 (>9 mm) follicles were less (P < 0.01) in DESL cows between Day 7 and Day 21. From Day 22 to Day 60, DESL-treated cows had more of Class 1 follicles and less Class 2 (P < 0.01) and Class 3 (P < 0.01) follicles, and lower plasma concentrations of progesterone and estradiol (P < 0.01). Concentrations of PGFM between Day 7 and Day 42 were not affected by treatment (P > 0.05). All cows ovulated in response to GnRH on Day 69. Subsequent luteal phase increases in plasma progesterone concentrations (Day 70 to Day 84) did not differ. The use of the DESL implant associated with PGF2alpha given 14 days later suppressed ovarian activity and caused plasma progesterone concentrations to remain < 1 ng/mL between Day 22 and Day 51. The DESL implant did not affect milk production.     

Maltotriose metabolism by Saccharomyces cerevisiae

Saccharomyces cerevisiae grew slower but reached higher cellular densities when grown on 20 g maltotriose l^–1 than on the same concentration of glucose or maltose. Antimycin A (3 mg l^–1) prevented growth on maltotriose, but not on glucose or maltose, indicating that it is not fermented but is degraded aerobically. This was confirmed by the absence of ethanol and glycerol production. Active uptake of maltotriose across the plasma membrane is the limiting step for metabolism, and the low rate of maltotriose transport observed in maltotriose-grown cells is probably one of the main reasons for the absence of maltotriose fermentation by S. cerevisiae cells.