Slow clearance of Plasmodium vivax with chloroquine amongst children younger than six months of age in the Brazilian Amazon

Plasmodium vivax is the most widespread parasite causing malaria, being especially prevalent in the Americas and Southeast Asia. Children are one of the most affected populations, especially in highly endemic areas. However, there are few studies evaluating the therapeutic response of infants with vivax malaria. This study retrospectively evaluated the parasitaemia clearance in children diagnosed with vivax malaria during the first five days of exclusive treatment with chloroquine (CQ). Infants aged less than six months old had a significantly slower parasitaemia clearance time compared to the group of infants and children between six months and 12 years old (Kaplan-Meier survival analysis; Wilcoxon test; p = 0.004). The impaired clearance of parasitaemia in younger children with vivax malaria is shown for the first time in Latin America. It is speculated that CQ pharmacokinetics in young children with vivax malaria is distinct, but this specific population may also allow the detection of CQ-resistant parasites during follow-up, due to the lack of previous immunity.     

Improving the analysis of designed studies by combining statistical modelling with study design information

Background  

In the fields of life sciences, so-called designed studies are used for studying complex biological systems. The data derived from these studies comply with a study design aimed at generating relevant information while diminishing unwanted variation (noise). Knowledge about the study design can be used to decompose the total data into data blocks that are associated with specific effects. Subsequent statistical analysis can be improved by this decomposition if these are applied on selected combinations of effects.     

Population parameters and exploitation rate of Sarotherodon galilaeus galilaeus (Cichlidae) in Lakes Doukon and Togbadji,Benin

Growth, mortality, recruitment and relative yield per recruit of Sarotherodon galilaeus galilaeus from Lakes Doukon and Togbadji were studied. Data on total length, total weight and sex were recorded on a monthly basis between January and December 2013 for S. g. galilaeus captured by local fishers. The estimated asymptotic lengths L_∞ were 26.2 and 23.6?cm for Lakes Doukon and Togbadji, respectively, while the growth rate K was 0.73 in Lake Doukon and 0.87 in Lake Togbadji. Estimates of fishing mortality, 0.27 and 0.47 y^?1 for Doukon and Togbadji, respectively, were low relative to natural mortality, 1.51 and 1.74 y^?1, respectively. Sizes at first sexual maturity were 12.8 and 13.2?cm for females and males, respectively, in Lake Doukon, and 11.5 and 12.4?cm for females and males, respectively, in Lake Togbadji. The size at first capture was estimated at 13.3 and 12.7?cm for Lakes Doukon and Togbadji, respectively, which, in the light of the size at maturity estimates, indicates that fish spawn at least once before capture. The current exploitation rates of 0.15 for Lake Doukon and 0.21 for Lake Togbadji suggest that their stocks of S. g. galilaeus are not overexploited in either lake.     

Complex contribution of cyclophilin D to Ca2+-induced permeability transition in brain mitochondria, with relation to the bioenergetic state

Cyclophilin D (cypD)-deficient mice exhibit resistance to focal cerebral ischemia and to necrotic but not apoptotic stimuli. To address this disparity, we investigated isolated brain and in situ neuronal and astrocytic mitochondria from cypD-deficient and wild-type mice. Isolated mitochondria were challenged by high Ca(2+), and the effects of substrates and respiratory chain inhibitors were evaluated on permeability transition pore opening by light scatter. In situ neuronal and astrocytic mitochondria were visualized by mito-DsRed2 targeting and challenged by calcimycin, and the effects of glucose, NaCN, and an uncoupler were evaluated by measuring mitochondrial volume. In isolated mitochondria, Ca(2+) caused a large cypD-dependent change in light scatter in the absence of substrates that was insensitive to Ruthenium red or Ru360. Uniporter inhibitors only partially affected the entry of free Ca(2+) in the matrix. Inhibition of complex III/IV negated the effect of substrates, but inhibition of complex I was protective. Mitochondria within neurons and astrocytes exhibited cypD-independent swelling that was dramatically hastened when NaCN and 2-deoxyglucose were present in a glucose-free medium during calcimycin treatment. In the presence of an uncoupler, cypD-deficient astrocytic mitochondria performed better than wild-type mitochondria, whereas the opposite was observed in neurons. Neuronal mitochondria were examined further during glutamate-induced delayed Ca(2+) deregulation. CypD-knock-out mitochondria exhibited an absence or a delay in the onset of mitochondrial swelling after glutamate application. Apparently, some conditions involving deenergization render cypD an important modulator of PTP in the brain. These findings could explain why absence of cypD protects against necrotic (deenergized mitochondria), but not apoptotic (energized mitochondria) stimuli.     

Effects of cyanobacterial extracellular products and gibberellic acid on salinity tolerance in Oryza sativa L

The XI International Rotifer Symposium was held during 11–18 March, 2006 at the National Autonomous University of Mexico Campus Iztacala located at the North Mexico City (Mexico). These triennial international meetings, first organized in Austria by Late Ruttner-Kolisko in September 1976, are gradually becoming the focal point of discussion and collaboration from rotifer workers across the world. The present XI symposium was attended by 125 participants from 20 nations. During this meeting, different themes of rotifer research from morphology to molecular biology were considered. In addition, there were four invited lectures and four workshops covering different themes of the symposium. During the last 30 years, rotifer research has witnessed gradual shift from the conventional morphological taxonomy to molecular and evolutionary systematics. While the basic rotifer ecological studies continue today, applied areas such as ecotoxicology and aquaculture have taken key roles in the recent meetings. The international rotifer meetings provide ample opportunities not only for exchange of ideas and recent research, but also for material and in establishing inter-personal relationships. Over the last 30 years, the number of participants attending the rotifer meetings has increased.     

RedeR: R/Bioconductor package for representing modular structures, nested networks and multiple levels of hierarchical associations

Visualization and analysis of molecular networks are both central to systems biology. However, there still exists a large technological gap between them, especially when assessing multiple network levels or hierarchies. Here we present RedeR, an R/Bioconductor package combined with a Java core engine for representing modular networks. The functionality of RedeR is demonstrated in two different scenarios: hierarchical and modular organization in gene co-expression networks and nested structures in time-course gene expression subnetworks. Our results demonstrate RedeR as a new framework to deal with the multiple network levels that are inherent to complex biological systems. RedeR is available from http://bioconductor.org/packages/release/bioc/html/RedeR.html.     

Phosphorylation of chloride-ATPase reconstituted from Aplysia gut

The present study was primarily done to compare cation-ATPase phosphorylation kinetics with an anion-ATPase's phosphorylation kinetics because of the paucity of information in this area. Utilizing a proteolipsomal preparation containing Cl(-)-ATPase from Aplysia gut, it was demonstrated that phosphorylation of this P-type ATPase was absolutely dependent upon Mg(2+). In organic phosphate concentrations directly (P(i)) enhanced phosphoprotein formation in the presence of increasing concentrations of Mg(2+). It was also shown that the calculated rate constant for E(1)-P formation was 26/sec. This approximated E(1)-P rate constant values for other electrogenic, uniport P-type ATPases, and therefore it was concluded from the results that the anion-ATPase phosphorylation kinetics did not greatly differ from cation-ATPase phosphorylation kinetics.     

Cl(-)-ATPases: Novel primary active transporters in biology

Five widely documented mechanisms of chloride transport across plasma membranes are anion-coupled antiport, sodium and hydrogen-coupled symport, Cl(-)channels, and an electrochemical coupling process. No genetic evidence has yet been provided for primary active chloride transport despite numerous reports of cellular Cl(-)-stimulated ATPases co-existing, in the same tissue, with uphill chloride transport that could not be accounted for by the five common chloride transport processes. Cl(-)-stimulated ATPase activity is a common property of practically all biological cells with the major location being of mitochondrial origin. It also appears that plasma membranes are sites of Cl(-)-stimulated ATPase activity. Recent studies of Cl(-)-stimulated ATPase activity and active chloride transport in the same membrane system, including liposomes, suggest a medication by the ATPase in net movement of chloride up its electrochemical gradient across plasma membranes. Further studies, especially from a molecular biological perspective, are required to confirm a direct transport role to plasma membrane-localized Cl(-)-stimulated ATPases. J. Exp. Zool. 289:215-223, 2001.     

Chloride transport in the ferret trachea

A net secretion of chloride stimulated by carbamylcholine was observed in whole trachea. Luminal anthracene-9-carboxylic acid inhibited the net secretion of chloride and the transepithelial potential difference across the isolated trachea. Submucosal ouabain inhibited the net secretion of chloride and submucosal ouabain, or submucosal bumetanide inhibited the transepithelial potential difference across the isolated trachea. Short-circuited flat sheets of trachea manifested a net secretion of chloride induced by carbamylcholine. Serosal ouabain inhibited the short-circuit current and net chloride flux across isolated flat sheets of trachea.