Prefrontal neurons of opposite spatial preference display distinct target selection dynamics.

Neurons in the primate dorsolateral prefrontal cortex (dlPFC) of one hemisphere are selective for the location of attended targets in both visual hemifields. Whether dlPFC neurons with selectivity for opposite hemifields directly compete with each other for target selection or instead play distinct roles during the allocation of attention remains unclear. We explored this issue by recording neuronal responses in the right dlPFC of two macaques while they allocated attention to a target in one hemifield and ignored a distracter on the opposite side. Forty-nine percent of the recorded neurons were target location selective. Neurons selective for contralateral targets (58%) systematically discriminated targets from distracters faster than neurons selective for ipsilateral targets (42%). Additionally, during trials in which sensory stimulation remained the same but both stimuli were task irrelevant and animals were required to detect a change in the color of a fixation spot, contralateral neurons still reliably discriminated the putative target from the distracter, whereas ipsilateral neurons did not. The latter result indicates that target-distracter discrimination by contralateral neurons could occur independently of discrimination by ipsilateral cells; thus, the two cell types may represent two different components of the prefrontal circuitry underlying the allocation of attention to targets in the presence of distracters. Moreover, the response of both contralateral and ipsilateral neurons to a single target was substantially reduced by the presence of a distracter in the contralateral hemifield. This result suggests that the presence of the distracter triggered inhibitory interactions within the dlPFC circuitry that suppressed responses to the attended target

Sharp emergence of feature-selective sustained activity along the dorsal visual pathway.

Sustained activity encoding visual working memory representations has been observed in several cortical areas of primates. Where along the visual pathways this activity emerges remains unknown. Here we show in macaques that sustained spiking activity encoding memorized visual motion directions is absent in direction-selective neurons in early visual area middle temporal (MT). However, it is robustly present immediately downstream, in multimodal association area medial superior temporal (MST), as well as and in the lateral prefrontal cortex (LPFC). This sharp emergence of sustained activity along the dorsal visual pathway suggests a functional boundary between early visual areas, which encode sensory inputs, and downstream association areas, which additionally encode mnemonic representations. Moreover, local field potential oscillations in MT encoded the memorized directions and, in the low frequencies, were phase-coherent with LPFC spikes. This suggests that LPFC sustained activity modulates synaptic activity in MT, a putative top-down mechanism by which memory signals influence stimulus processing in early visual cortex

Volatile compounds of Morinda royoc L. fruit at two ripening stages

Morinda royoc L. (Rubiaceae), commonly known in Cuba as garañón, piñipiñi or piña ratón arbusto, is a plant typically found in coastal hammocks with medicinal properties. Application of headspace-solid phase microextraction combined with gas chromatography-mass spectrometry was used to analyze, for the first time, the volatile compounds of Morinda royoc L. fruits at to ripening stages. A fiber of polydimethylsiloxane-divinylbenzene (PDMS/DVB) was used for the extraction. The analyses led to the identification of 137 compounds, including 42 esters, 22 acids, 17 alcohols, 14 ketones, 14 terpenes, 9 aldehydes, 9 sulfur-compounds, 4 lactones, 3 phenols and derivatives, 3 paraffins and a nitrogen-compound. Qualitative and quantitatively, acids were a major chemical class of compounds in both maturity stages, mainly in the ripe stage. Although some compounds remain without changes in both ripening stages, the composition of certain volatile compounds clearly differs in both stages. The over-ripe fruit showed significantly higher amounts of 3-methyl-3-butenyl butanoate, 3-methyl-3-butenyl hexanoate and 3-methyl-3-butenyl octanoate, while 3-methyl-3-butenyl acetate, benzyl acetate and benzyl butanoate significantly decreased. The content of butanoic acid and 2-methylbutanoic acid increased from mature to over-ripe stage, while the major part of the other acids decreased during maturation

Crianza de animales domésticos como factor de riesgo de fascioliasis humana

The aim of this study was to determine the association of fascioliasis with the breeding of animals, housing characteristics and food consumption of children in the district of Santa María de Chicmo, Apurimac, Peru. Serological samples were taken from 493 children aged 6 to 16 years, males and females, with the informed consent of their parents. The prevalence, determined by the immunoblot technique was 5.3% (95% CI = 3.2% -7.4%, 26/493). The univariate analysis showed that the breeding of cattle and cats, and raising three or more pigs were factors associated with fascioliasis. The breeding of more than five sheep resulted as a protection factor. Fascioliasis in children was not associated with the characteristics of the dwellings or the consumption of food. It is concluded that the district of Santa María de Chicmo is mesoendemic for fascioliasis in children, and that the rearing of some species of domestic animals involves risk of human fascioliasis.  El estudio tuvo como objetivo determinar la asociación de fascioliasis con la crianza de animales, características de la vivienda y consumo de alimentos de niños del distrito de Santa María de Chicmo, Apurímac, Perú. Se tomaron muestras serológicas a 493 niños de 6 a 16 años, de ambos sexos, con el consentimiento informado de sus padres. La prevalencia, determinada mediante la técnica de inmunoblot fue de 5.3% (IC95%=3.2%-7.4%; 26/493). El análisis univariado demostró que la crianza de bovinos y gatos, así como la crianza de tres o más cerdos fueron factores asociados a fascioliasis. La crianza de más de cinco ovinos configuró un factor de protección. La fascioliasis en niños no estuvo asociada a las características de las viviendas ni al consumo de alimentos. Se concluye que el distrito de Santa María de Chicmo es mesoendémico para fascioliasis en niños, y que la crianza de algunas especies de animales domésticos implica riesgo de fascioliasis humana

Variaciones en el número y función de los linfocitos asesinos naturales durante infecciones recurrentes o graves

Introduction: The information about defects affecting natural killer cell (NK) development and activity in patients with an abnormal increase of recurrent infections is scarce.Objective: To perform a systematic analysis of NK abnormalities in patients with recurrent infections.Materials and methods: Our study enrolled twenty patients with severe or recurrent viral infections. Natural killer cell subsets, surface receptors expression and cytotoxicity were analyzed. Results were compared with those from age- and sex-matched healthy controls.Results: Transient alterations were observed in the percentages and absolute numbers of NK cells in patients with infection active episodes. We also described five patients with stable disturbances in the distribution of NK cell subpopulations. These defects are mainly due to a decrease in the CD56dimCD16bright cells in peripheral blood. In addition, NK cell function abnormalities were observed in some patients, however, those were always transient and mainly associated to active disease.Conclusions: These findings demonstrate transient alterations in the percentages and absolute numbers of NK cells in patients with recurrent or severe infection. Also, stable disturbances in CD56dimCD16bright NK cells are observed in these patients. Nevertheless, these parameters must be thoroughly studied to determine the mechanisms that entail these immune abnormalities and investigate how they alter the immune response.Introducción. Existen pocos datos sobre los defectos que afectan el desarrollo y función de los linfocitos asesinos naturales (natural killers, NK) en pacientes con un incremento anormal en la recurrencia de infecciones.Objetivo. Realizar una evaluación sistemática de las diferentes subpoblaciones y la función de estas células en pacientes con infecciones recurrentes.Materiales y métodos. Se incluyeron 20 pacientes con infecciones graves o recurrentes y se analizaron las subpoblaciones y la respuesta citotóxica de los linfocitos NK en sangre periférica. Los resultados de los pacientes se compararon con controles sanos pareados por edad y sexo.Resultados. Los pacientes con episodios infecciosos activos presentaron anormalidades transitorias en el porcentaje o el número absoluto de linfocitos NK. Se caracterizaron, además, cinco pacientes con alteraciones persistentes en la distribución de las subpoblaciones de linfocitos NK. Estas alteraciones se debieron principalmente a la disminución de células CD56dimCD16bright. Se evidenciaron, también, defectos en la función de los linfocitos NK en algunos de nuestros pacientes; sin embargo, estas alteraciones fueron transitorias y se asociaron principalmente a la fase activa de la enfermedad.Conclusiones. Nuestros resultados evidencian defectos transitorios en el número y función de los linfocitos NK en pacientes con infecciones recurrentes o graves, además de alteraciones persistentes en los LNK CD56dimCD16bright en algunos individuos. Es necesario profundizar en los mecanismos que conllevan al desarrollo de estos defectos inmunes y estudiar cómo estas alteraciones influyen en la respuesta inmune

Aportaciones hidrogeológicas al estudio arqueológico de los orígenes de la Edad del Bronce de La Mancha: la cueva monumentalizada de Castillejo del Bonete (Terrinches, Ciudad Real-España)

Estudios recientes indican que las motillas, asentamientos de la Edad del Bronce de La Mancha, pudieron ser las más antiguas captaciones de agua subterránea en la Península Ibérica. Pero ¿por qué no existen motivas en el Campo de Montiel, territorio ubicado tradicionalmente en esta área cultural? En Castillejo del Bonete, sitio arqueológico situado en esa comarca, existe una cueva que fue utilizada y sellada durante la Prehistoria Reciente. Se presenta ahora la primera investigación paleohidrogeológica interdisciplinar en La Mancha, que ha analizado manantiales y niveles de agua subterránea del acuífero de Campo de Montiel, así como el interior de la sima de Castillejo del Bonete. Las conclusiones avanzan una relación entre el sustrato hidrogeomorfológico y la distribución espacial de las motillas. Además permiten descartar que la sima de Castillejo del Bonete fuera utilizada como mina o como acceso al acuífero, dos de las hipótesis de trabajo planteadas. De ese modo cobra fuerza que Castillejo del Bonete fuera un excepcional monumento funerario y simbólico durante el Calcolítico y la Edad del Bronce, perteneciente a una nueva clase de asentamientos desconocidos hasta ahora en el grupo cultural de la Edad del Bronce de La Mancha

Locus coeruleus imaging as a biomarker for noradrenergic dysfunction in neurodegenerative diseases.

Pathological alterations to the locus coeruleus, the major source of noradrenaline in the brain, are histologically evident in early stages of neurodegenerative diseases. Novel MRI approaches now provide an opportunity to quantify structural features of the locus coeruleus in vivo during disease progression. In combination with neuropathological biomarkers, in vivo locus coeruleus imaging could help to understand the contribution of locus coeruleus neurodegeneration to clinical and pathological manifestations in Alzheimer's disease, atypical neurodegenerative dementias and Parkinson's disease. Moreover, as the functional sensitivity of the noradrenergic system is likely to change with disease progression, in vivo measures of locus coeruleus integrity could provide new pathophysiological insights into cognitive and behavioural symptoms. Locus coeruleus imaging also holds the promise to stratify patients into clinical trials according to noradrenergic dysfunction. In this article, we present a consensus on how non-invasive in vivo assessment of locus coeruleus integrity can be used for clinical research in neurodegenerative diseases. We outline the next steps for in vivo, post-mortem and clinical studies that can lay the groundwork to evaluate the potential of locus coeruleus imaging as a biomarker for neurodegenerative diseases.Includes MRC, NIHR, Wellcome Trust, H2020 and FP7

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic