First Detection of Human Polyomaviruses in HIV Patients with Suspected Neurological Disease in Montería, Colombia

Objective: The objective is to establish the presence of JC and/or BK polyomavirus in HIV patients with symptoms of encephalitis and/or meningitis. Methodology: From September 2009 to December 2011, a prospective study was conducted. 34 HIV patients with symptoms consistent with encephalitis and/or meningitis were included. The work was conducted in 3 hospitals in the city of Monteria. Viral DNA extraction was performed on samples of cerebrospinal fluid (CSF) using a commercial kit (Quiagen, USA). The detection of BKV and JCV was performed by multiplex real-time PCR (LightMix?, Roche Diagnostics, Germany) with primers specific for the short t antigen gene fragment, labeled probes and one internal control. Results: In 9 (26%) of 34 patients included in the study, JCV virus was detected;only 1 (3%) patient had coinfection with JCV/BKV. The mortality rate was 3%. The cytochemical examination of CSF in positive patients presented average values: 40.7 mg/dL glucose, 171.66 mg/dL protein, 19.8 mm3 leukocytes, and 109.8 mm3 erythrocytes. Conclusion: The findings demonstrate that JCV and BKV have a significant occurrence in HIV patients with CSF infections in Monteria.

Correlative microscopy of Purkinje cells

The Purkinje cell and their synaptic contacts have been described using(1)light microsocopy,(2)transmission and scanning electron microscopy,and freeze etching technique,(3)conventional and field emission scanning electron microscopy and cryofracture methods,(4)confocal laser scanning microscopy using intravital stain FM64,and(5)immunocytochemical techniques for Synapsin-I,PSD9-5,GluR1 subunit of AMPA receptors,N-cadherin,and CamKII alpha.The outer surface and inner content of plasma membrane,cell organelles,cytoskeleton,nucleus,dendritic and axonal processes have been exposed and analyzed in a three-dimensional view.The intramembrane morphology,in bi-and three-dimensional views,and immunocytochemical labeling of synaptic contacts with parallel and climbing fibers,basket and stellate cell axons have been characterized.Freeze etching technique,field emission scanning microscopy and cryofracture methods,and GluR1 immunohistochemistry showed the morphology and localization of postsynaptic receptors.Purkinje cell shows N-cadherin and CamKII alpha immunoreactivity.The correlative microscopy approach provides a deeper understanding of structure and function of the Purkinje cell,a new three-dimensional outer and inner vision,a more detailed study of afferent and intrinsic synaptic junctions,and of intracortical circuits.

Distributed Differences Structures Underlie Gating between the Kin Channel KAT1 and the Kout Channel SKOR

The family of voltage-gated （Shaker-like） potassium channels in plants includes both inward-rectifying （Kin） channels that allow plant cells to accumulate K＋ and outward-rectifying （Kout） channels that mediate K＋ efflux. Despite their dose structural similarities, Kin and Kout channels differ in their gating sensitivity towards voltage and the extracellular K＋ concentration. We have carried out a systematic program of domain swapping between the Kout channel SKOR and the Kin channel KAT1 to examine the impacts on gating of the pore regions, the S4, S5, and the S6 helices. We found that, in particular, the N-terminal part of the S5 played a critical role in KAT1 and SKOR gating. Our findings were supported by molecular dynamics of KAT1 and SKOR homology models. In silico analysis revealed that during channel opening and closing, displacement of certain residues, especially in the S5 and S6 segments, is more pronounced in KAT1 than in SKOR. From our analysis of the S4-S6 region, we conclude that gating （and K＋-sensing in SKOR） depend on a number of structural elements that are dispersed over this -145-residue sequence and that these place additional constraints on configurational rearrangement of the channels during gating.

Foliar persistence and residual activity of methoxyfenozide against beet armyworm （Lepidoptera： Noctuidae）

A greenhouse study was conducted to investigate the persistence of methoxyfenozide in pepper （Capsicum annuum L.） foliage. An aqueous suspension of methoxyfenozide was sprayed on pepper plants at concentrations of 72 and 144 mg of active ingredient （a.i.）/L. Foliage was collected at different intervals of time （0, 3, 5, 10, 20, 30, 40, and 50 days） after the treatment, and the methoxyfenozide residue was measured by high-performance liquid chromatography. The foliage was also used in bioas- says to determine the residual toxicity on and the consumption rate of the third-instar larvae of the beet armyworm, Spodoptera exigua （Htibner） （Lepidoptera： Noctuidae）. The methoxyfenozide concentrations observed after 50 days had decreased to 19 and 69μg/g per sample, corresponding to a loss of 61% and 28% from the application concentrations of 72 and 144 mg a.i./L, respectively. When fitting a first-order kinetics degradation model, the half-life （DT50） of this compound was 76 days. Both application concentrations of methoxyfenozide caused a high mortality rate （〉97%） when the larvae were fed the pepper foliage collected at all of the time intervals. Lastly, at all of the time points, the consumption rate by the larvae was reduced to between 57% and 92% for both concentrations that were bioassayed. Our results indicate that, under the present greenhouse conditions, the degradation of methoxyfenozide was slower than that reported by other authors and that its residues were highly toxic to S. exigua larvae. The implications of these results for the management programs of this pest are discussed.

Effect of Mitochondrial Dysfunction on Carbon Metabolism and Gene Expression in Flower Tissues of Arabidopsis thaliana

We characterized the transcriptomic response of transgenic plants carrying a mitochondrial dysfunction induced by the expression of the unedited form of the ATP synthase subunit 9. The u-ATP9 transgene driven by A9 and APETALA3 promoters induce mitochondrial dysfunction revealed by a decrease in both oxygen uptake and adenine nucleo- tides （ATP, ADP） levels without changes in the ATIP/ADP ratio. Furthermore, we measured an increase in ROS accumulation and a decrease in glutathione and ascorbate levels with a concomitant oxidative stress response. The transcriptome analysis of young Arabidopsis flowers, validated by qRT-PCR and enzymatic or functional tests, showed dramatic changes in u-ATP9 plants. Both lines display a modification in the expression of various genes involved in carbon, lipid, and cell wall metabolism, suggesting that an important metabolic readjustment occurs in plants with a mitochondrial dysfunction. Interestingly, transcript levels involved in mitochondrial respiration, protein synthesis, and degradation are affected. More- over, the levels of several mRNAs encoding for transcription factors and DNA binding proteins were also changed. Some of them are involved in stress and hormone responses, suggesting that several signaling pathways overlap. Indeed, the tran- scriptome data revealed that the mitochondrial dysfunction dramatically alters the expression of genes involved in signaling pathways, including those related to ethylene, absicic acid, and auxin signal transduction. Our data suggest that the mitochondrial dysfunction model used in this report may be useful to uncover the retrograde signaling mechanism between the nucleus and mitochondria in plant cells.

Spatiotemporal variation in the adult sex ratio,male aggregation,and movement of two tropical cloud forest dung beetles

While theory suggests that at conception the sex ratio should be balanced(1:1),this can be variable across space and time in wild populations.Currently,studies of the environmental factors that regulate adult sex ratio(ASR)in species with different life history traits are scarce.Using capture–recapture over a year,we analyzed the influence of habitat type(forest and nonforest)and season(rainy and dry)on variation in ASR,male aggregation and the trajectory movement of 2 dung beetle species with different life history traits:Deltochilum mexicanum(a hornless roller species)and Dichotomius satanas(a tunneler species with horns on its head and thorax).We found opposite tendencies.The D.mexicanum population tends to be female-biased,but the population of D.satanas tends to be predominantly male,and observed values were not related to habitat type or season.However,the 95%confidence intervals estimated were highly variable between seasons depending on habitat.On examining the monthly variation in ASR for both habitats,we found that it depends on the species.In addition,male aggregation differed between species depending on habitat type and season,and species movement patterns were closely related to their habitat preferences.Based on our results,we argue that comparative population studies of species with different life history traits are necessary to understand the variation in demographic parameters as well as its ecological and evolutionary implications in the face of spatial and climatic environmental variation.