Life & Health Sciences

Activity and shelter-related behavior in Rhodnius prolixus: The role of host odours


ABSTRACT

Triatomine bugs are considered nocturnal insects that feed on the blood of vertebrates and remain hidden inside narrow shelters during daylight hours. Nevertheless, it is not clear whether these insects become active and leave their shelters on a daily basis, less frequently or, even fortnightly. Activity patterns were studied in Rhodnius prolixus Stål, 1859 (Hemiptera: Triatominae) associated with shelters to evaluate whether the decision to leave a shelter depends on bug starvation and the presence of host odours. Experiments were conducted with groups of 5th instar nymphs released in an experimental arena offering an artificial shelter consisting of a piece of corrugated cardboard positioned in its centre. Results indicate that host odours promoted a significant increase in shelter related activity, i.e. shelter-leaving or entering movements, and also in bug locomotion. This increase could only be observed with bugs starved for 30 or 60 days, but not for 21 days. Most R. prolixus nymphs that left shelters and engaged in locomotory activity were starved and in the presence of host odours. Even though R. prolixus is mostly considered a very active and “aggressive” triatomine, our results contradict this perspective and suggest that its main strategy regarding hosts is to wait and carefully evaluate feeding chances before becoming exposed. This behavioural strategy might have arisen through their evolution in palm trees in association with a diverse fauna that may impose predation risks.


Molecular bases of sensory processes in kissing bugs, vectors of Chagas disease


ABSTRACT

Sensory processes represent an information gathering interface between animals and their surrounding world. Therefore, they serve to scan the environment for resources and threats. The behavior of kissing bugs has been studied to aid their control because they transmit Chagas disease to humans. Besides, a few triatomines represent important insect models since Wigglesworth times. These hematophagous insects rely on different sensory systems to scan their environment for blood-sources, mating partners and hiding places. The study of the molecular bases of sensory processes has undergone a dramatic progress due the advent of new technologies allowing mass-sequencing of genes. Here we focus on reviewing the fundamental knowledge gathered to date about the molecular bases of kissing bug sensory processes.


A novel 3D nanofibre scaffold conserves the plasticity of glioblastoma stem cell invasion by regulating galectin-3 and integrin-β1 expression


ABSTRACT

Glioblastoma Multiforme (GBM) invasiveness renders complete surgical resection impossible and highly invasive Glioblastoma Initiating Cells (GICs) are responsible for tumour recurrence. Their dissemination occurs along pre-existing fibrillary brain structures comprising the aligned myelinated fibres of the corpus callosum (CC) and the laminin (LN)-rich basal lamina of blood vessels. The extracellular matrix (ECM) of these environments regulates GIC migration, but the underlying mechanisms remain largely unknown. In order to recapitulate the composition and the topographic properties of the cerebral ECM in the migration of GICs, we have set up a new aligned polyacrylonitrile (PAN)-derived nanofiber (NF) scaffold. This system is suitable for drug screening as well as discrimination of the migration potential of different glioblastoma stem cells. Functionalisation with LN increases the spatial anisotropy of migration and modulates its mode from collective to single cell migration. Mechanistically, equally similar to what has been observed for mesenchyma I migration of GBM in vivo, is the upregulation of galectin-3 and integrin-beta 1 in Gli4 cells migrating on our NF scaffold. Downregulation of Calpain-2 in GICs migrating in vivo along the CC and in vitro on LN-coated NF underlines a difference in the turnover of focal adhesion (FA) molecules between single-cell and collective types of migration.


Inpatient trunk exercises after recent stroke: an update meta-analysis of randomized controlled trials.


ABSTRACT

INTRODUCTION:Although the role of trunk exercises in the chronic phase of stroke is acknowledged, the addition of specific inpatient training in the subacute stage is a matter of debate and varies among centers. Recent new evidence suggests the question should be revisited. OBJECTIVE:To assess the impact of the addition of specific trunk training to inpatient rehabilitation protocols after a recent stroke. METHODS:A systematic review was performed assessing the impact of inpatient trunk training. The search was performed in LILACS, SciELO, PEDro, Cochrane, and NCBI PubMed databases for clinical trials published up to December 31st, 2017. The initial bibliographic research identified 3202 articles. After analyzing the titles, 19 abstracts were selected for detailed analysis. After application of the eligibility criteria, the final selection included nine studies. Outcome measurements from the same evaluation instruments were submitted to a meta-analysis to improve homogeneity (7 studies). RESULTS:All patients in the included studies were recruited less than three months after a stroke. Seven studies assessed trunk control using the Trunk Impairment Scale (TIS). There was a significant improvement in trunk control with a pooled increase in TIS score of 3.3 points from the baseline (CI95:2.54–4.06, p 


Stereoscopic images from computed tomography angiograms


ABSTRACT

Objective
To present an adaptation of the anaglyph photography technique to be used with radiological images from computed tomography angiograms, enabling stereoscopic visualization of a patient's individual abnormal vascular anatomy for teaching, case discussion, or surgical planning purposes.

Methods
Traditional anaglyph procedures with actual objects yield 2 independent photographs, simulating the image perceived by each eye. Production of anaglyphs from angiograms involve 3 basic procedures: volume rendering, image capture, and image fusion. Volume renderings were reconstructed using a free, open-source DICOM (Digital Imaging and Communications in Medicine) reader. Subsequently, the virtual object was positioned to mimic the operator's angle of view, and different perspectives of the reconstructed volume could be obtained through exclusively horizontal rotation. The 2 images were then fused after their color composition was modified so that each eye would perceive only 1 image when using anaglyph glasses.

Results
Forty-three angiograms were reviewed for the purpose of this study and a total of 6 examinations were selected for illustration of the technique. Stereoscopic display was possible for all of them and in the 3 types of support tested: computer monitor, tablet, and smartphone screens.

Conclusions
Anaglyph display of computed tomography angiograms is an effective and low-cost alternative for the stereoscopic visualization of a patient's individual intracranial vascular anatomy.


Combining proprioceptive neuromuscular facilitation and virtual reality for improving sensorimotor function in stroke survivors: a randomized clinical trial


ABSTRACT

Aim of the study: To assess a program combining virtual reality (VR) games and proprioceptive neuromuscular facilitation (PNF), and to compare it to the standalone techniques in stroke survivors.
Methods: A randomized controlled clinical trial. Forty-eight participants were recruited in the outpatient clinic of a University Hospital in Salvador, Brazil. They were randomly assigned to three groups (n=16 each): PNF, VR, and PNF/VR. Participants attended twice-weekly fifty-minute sessions over a two-month period. The PNF/VR group performed both PNF and virtual reality exercises employing Nintendo Wii electronic games. Motor performance was assessed before and immediately after the treatment using the Fugl-Meyer Assessment scale.
Results: Improvement in the mean scores was observed after treatment independent of the allocation group with significant intra-group changes: 14.5, 10.5, and 10.4 for PNF, VR and PNF/VR, respectively. Score changes were also observed in the analyses of specific sections as follows: (1) A significant improvement in the passive movement and pain score was observed in the PNF and PNF/VR groups. (2) The same was observed for the motor function of the upper limb in all groups, for the motor function of the lower limb in the VR group and for balance in the PNF and PNF/VR groups.
Conclusion: The use of a program combining virtual rehabilitation and PNF presented results that were comparable to those obtained with the isolated techniques


Middle Longitudinal Fasciculus in the Human Brain from Fiber Dissection


ABSTRACT

Although the middle longitudinal fasciculus (MdLF) is not part of the insular lobe, it penetrates the temporal operculum, which is manipulated or partially removed during surgical approaches to the insula. We present a comprehensive description of that fascicle and its anatomical relationships with neighboring structures that have been described in previous chapters. It has been hypothesized that MdLF plays a role in attention and language processing; however studies with peroperative subcortical electrostimulation or temporal lobectomies did not demonstrate permanent language deficits following resection of its anterior segment. The MdLF has close relationships to adjacent bundles, such as the arcuate fasciculus and the inferior fronto-occipital fasciculus that are required to be recognized and differentiated for adequate interpretation of tractography images and surgical planning.


Gross Anatomy of the Human Insula


ABSTRACT

When the lips of the lateral fissure are separated from each other, a new group of sulci and gyri appear. They are arrayed together in the form of an island, which is the reason why the German anatomist, Johann Christian Reil, named them “the insular lobe”. Bordered by the limiting sulci, its general form resembles that of an oblique pyramid with a triangular base and low height. Although some anatomical variation exists, the insula presents a systematizable internal organization and well-defined anatomical relationships with deep and superficial cerebral structures, such as the extreme capsule and the cerebral opercula. In this chapter we review concepts of the insular morphology that are important to the fields of neurosurgery and neuroimaging.


Zoonotic helminth exposure and risk of allergic diseases: A study of two generations in Norway


ABSTRACT

Background: Animal and human studies indicate that definitive host helminth infections may confer protection from allergies. However, zoonotic helminths, such as Toxocara species (spp.), have been associated with increased allergies.

Objective: We describe the prevalence of Toxocara spp. and Ascaris spp. seropositivity and associations with allergic diseases and sensitization, in 2 generations in Bergen, Norway.

Methods: Serum levels of total IgG4, anti-Toxocara spp. IgG4 and Ascaris spp. IgG4 were established by ELISA in 2 cohorts: parents born 1945-1972 (n = 171) and their offspring born 1969-2003 (n = 264). Allergic outcomes and covariates were recorded through interviews and clinical examinations including serum IgEs and skin prick tests.

Results: Anti-Ascaris spp. IgG4 was detected in 29.2% of parents and 10.3% of offspring, and anti-Toxocara spp. IgG4 in 17.5% and 8.0% of parents and offspring, respectively. Among offspring, anti-Toxocara spp. IgG4 was associated with pet keeping before age 15 (OR = 6.15; 95% CI = 1.37-27.5) and increasing BMI (1.16 [1.06-1.25] per kg/m2). Toxocara spp. seropositivity was associated with wheeze (2.97[1.45- 7.76]), hayfever (4.03[1.63-9.95]), eczema (2.89[1.08-7.76]) and cat sensitization (5.65[1.92-16.6]) among offspring, but was not associated with allergic outcomes among parents. Adjustment for childhood or current pet keeping did not
alter associations with allergies. Parental Toxocara spp. seropositivity was associated with increased offspring allergies following a sex-specific pattern.

Conclusions & Clinical Relevance: Zoonotic helminth exposure in Norway was less frequent in offspring than parents; however, Toxocara spp. seropositivity was associated with increased risk of allergic manifestations in the offspring generation, but not among parents. Changes in response to helminth exposure may provide insights into the increase in allergy incidence in affluent countries.


Emergomyces africanus in Soil, South Africa


ABSTRACT

We detected Emergomyces africanus, a thermally dimorphic fungus that causes an HIV-associated systemic mycosis, by PCR in 18 (30%) of 60 soil samples from a wide range of habitats in South Africa. Direct and indirect culture techniques were unsuccessful. Experimental intraperitoneal inoculation of conidia induced murine disease.