Intérêt de l’imagerie hybride TEMP/TDM dans la localisation des glandes parathyroïdes ectopiques : à propos de 3 cas

The presence of a parathyroid gland in ectopic position constitutes one of the leading causes of surgery failure. For this purpose, scintigraphy takes a major place in the anatomical localization of pathological parathyroid and so facilitates its treatment. The advent of hybrid cameras combining single photon emission tomography to CT (SPECT/CT) has further strengthened the contribution of this imaging modality in the precise localization of ectopic parathyroid and its anatomical relationships. The objective of our work is to illustrate the interest of hybrid imaging SPECT/CT, compared to planar scintigraphy and ultrasounds within the framework of primary hyperparathyroidism, particularly ectopic situation through three cases.     

Diurnal Variations of Striatal D2 Dopaminergic Receptors and its Relation with Haloperidol-induced Catalepsy

In spite of the clear evidences for the blockade of dopaminergic D2 receptors as the mechanism of action for haloperidol-induced catalepsy, the contribution of pharmacokinetic and pharmacodynamic aspects on the diurnal modulation of haloperidol-induced catalepsy is controversial. We studied the diurnal variations of striatal dopamine receptors and its relation with catalepsy diurnal variations. The [3 H]-spiperone binding to dopamine receptors had a clear rhythm with a peak at 00:00 to 03:00 h, and a trough at 12:00 to 18:00 h. Haloperidol-produced catalepsy measured with the four-cork test, also showed a clear rhythm, with a peak at 00:00 h and trough at 9:00 h. The dose-response curves at peak and trough of catalepsy had the same ED 50 (0.12 mg), with time-related changes in the maximal effect. Similar diurnal variations between catalepsy and dopamine receptor binding, indicate a relevant role of temporal pharmacodynamics of haloperidol on the modulation of its behavioral effects.     

Distribution patterns of Dikarya in arid and semiarid soils of Baja California,Mexico

Approximately four-fifths of the land area of Baja California (BC) in Mexico are occupied by arid and semiarid soils, the mycobiota of which is virtually uncharacterized. In the first culture-independent study of the mycobiota of BC, we collected soil from five different locations in the region and constructed a Dikarya-specific gene library for the ITS region of nuclear ribosomal DNA. Clones were analyzed by RFLP, were sequenced for phylogenetic analyses, and diversity and similarity indices were calculated. The ascomycete Penicillium dipodomyicola was the most frequent fungus found in soil at the most arid location studied, and the basidiomycete Coprinellus radians was the most frequent at the location receiving the highest rainfall. Other frequent members of the soil mycobiota were identified as Alternaria spp., Ceratobasidium sp., Coniozyma leucospermi, Nematoctonus robustus, Penicillium griseofulvum, Tulostoma kotlabae and uncultured members of the Dikarya. Several sequences were identified as those of uncultured fungi, one of which was previously reported from other hot deserts. Arid soils and the transitional zones between arid and semiarid soils had the most similar fungal diversity, with the former soils having a community from which basidiomycetes were absent, and the soil receiving the highest precipitation having a community dominated by basidiomycetes.     

Fabrication of Polymeric Visual Decoys for the Male Emerald Ash Borer (Agrilus planipennis)

Through a bioreplication approach, we have fabricated artificial visual decoys for the invasive species Agrilus planipennis—commonly known as the Emerald Ash Borer (EAB). The mating behavior of this species involves an overflying EAB male pouncing on an EAB female at rest on an ash leaflet before copulating. The male spots the female on the leaflet by visually detecting the iridescent green color of the female's elytra. As rearing EAB and then deploying dead females as decoys for trapping is both arduous and inconvenient, we decided to fabricate artificial decoys. We used a dead female to make a negative die of nickel and a positive die of epoxy. Decoys were then made by first depositing a quarter-wave-stack Bragg reflector on a polymer sheet and then stamping it with a pair of matched negative and positive dies to take the shape of the upper surface of an EAB female. As nearly 100 artificial decoys were fabricated from just one EAB female, this bioreplication process is industrially scalable. Preliminary results from a field trapping test are indicative of success.     

Our Faces in the Dog's Brain: Functional Imaging Reveals Temporal Cortex Activation during Perception of Human Faces

Dogs have a rich social relationship with humans. One fundamental aspect of it is how dogs pay close attention to human faces in order to guide their behavior, for example, by recognizing their owner and his/her emotional state using visual cues. It is well known that humans have specific brain regions for the processing of other human faces, yet it is unclear how dogs’ brains process human faces. For this reason, our study focuses on describing the brain correlates of perception of human faces in dogs using functional magnetic resonance imaging (fMRI). We trained seven domestic dogs to remain awake, still and unrestrained inside an MRI scanner. We used a visual stimulation paradigm with block design to compare activity elicited by human faces against everyday objects. Brain activity related to the perception of faces changed significantly in several brain regions, but mainly in the bilateral temporal cortex. The opposite contrast (i.e., everyday objects against human faces) showed no significant brain activity change. The temporal cortex is part of the ventral visual pathway, and our results are consistent with reports in other species like primates and sheep, that suggest a high degree of evolutionary conservation of this pathway for face processing. This study introduces the temporal cortex as candidate to process human faces, a pillar of social cognition in dogs.     

Criterion-Related Validity of the Distance- and Time-Based Walk/Run Field Tests for Estimating Cardiorespiratory Fitness: A Systematic Review and Meta-Analysis

Objectives

The main purpose of the present meta-analysis was to examine the criterion-related validity of the distance- and time-based walk/run tests for estimating cardiorespiratory fitness among apparently healthy children and adults.

Materials and Methods

Relevant studies were searched from seven electronic bibliographic databases up to August 2015 and through other sources. The Hunter-Schmidt’s psychometric meta-analysis approach was conducted to estimate the population criterion-related validity of the following walk/run tests: 5,000 m, 3 miles, 2 miles, 3,000 m, 1.5 miles, 1 mile, 1,000 m, ½ mile, 600 m, 600 yd, ¼ mile, 15 min, 12 min, 9 min, and 6 min.

Results

From the 123 included studies, a total of 200 correlation values were analyzed. The overall results showed that the criterion-related validity of the walk/run tests for estimating maximum oxygen uptake ranged from low to moderate (r_p = 0.42–0.79), with the 1.5 mile (r_p = 0.79, 0.73–0.85) and 12 min walk/run tests (r_p = 0.78, 0.72–0.83) having the higher criterion-related validity for distance- and time-based field tests, respectively. The present meta-analysis also showed that sex, age and maximum oxygen uptake level do not seem to affect the criterion-related validity of the walk/run tests.

Conclusions

When the evaluation of an individual’s maximum oxygen uptake attained during a laboratory test is not feasible, the 1.5 mile and 12 min walk/run tests represent useful alternatives for estimating cardiorespiratory fitness. As in the assessment with any physical fitness field test, evaluators must be aware that the performance score of the walk/run field tests is simply an estimation and not a direct measure of cardiorespiratory fitness.     

Structural and Affinity Determinants in the Interaction between Alcohol Acyltransferase from F. x ananassa and Several Alcohol Substrates: A Computational Study

Aroma and flavor are important factors of fruit quality and consumer preference. The specific pattern of aroma is generated during ripening by the accumulation of volatiles compounds, which are mainly esters. Alcohol acyltransferase (AAT) (EC 2.3.1.84) catalyzes the esterification reaction of aliphatic and aromatic alcohols and acyl-CoA into esters in fruits and flowers. In Fragaria x ananassa, there are different volatiles compounds that are obtained from different alcohol precursors, where octanol and hexanol are the most abundant during fruit ripening. At present, there is not structural evidence about the mechanism used by the AAT to synthesize esters. Experimental data attribute the kinetic role of this enzyme to 2 amino acidic residues in a highly conserved motif (HXXXD) that is located in the middle of the protein. With the aim to understand the molecular and energetic aspects of volatiles compound production from F. x ananassa, we first studied the binding modes of a series of alcohols, and also different acyl-CoA substrates, in a molecular model of alcohol acyltransferase from Fragaria x ananassa (SAAT) using molecular docking. Afterwards, the dynamical behavior of both substrates, docked within the SAAT binding site, was studied using routine molecular dynamics (MD) simulations. In addition, in order to correlate the experimental and theoretical data obtained in our laboratories, binding free energy calculations were performed; which previous results suggested that octanol, followed by hexanol, presented the best affinity for SAAT. Finally, and concerning the SAAT molecular reaction mechanism, it is suggested from molecular dynamics simulations that the reaction mechanism may proceed through the formation of a ternary complex, in where the Histidine residue at the HXXXD motif deprotonates the alcohol substrates. Then, a nucleophilic attack occurs from alcohol charged oxygen atom to the carbon atom at carbonyl group of the acyl CoA. This mechanism is in agreement with previous results, obtained in our group, in alcohol acyltransferase from Vasconcellea pubescens (VpAAT1).     

Massive excretion of calcium oxalate from late prepupal salivary glands of Drosophila melanogaster demonstrates active nephridial‐like anion transport

The Drosophila salivary glands (SGs) were well known for the puffing patterns of their polytene chromosomes and so became a tissue of choice to study sequential gene activation by the steroid hormone ecdysone. One well‐documented function of these glands is to produce a secretory glue, which is released during pupariation to fix the freshly formed puparia to the substrate. Over the past two decades SGs have been used to address specific aspects of developmentally‐regulated programmed cell death (PCD) as it was thought that they are doomed for histolysis and after pupariation are just awaiting their fate. More recently, however, we have shown that for the first 3–4 h after pupariation SGs undergo tremendous endocytosis and vacuolation followed by vacuole neutralization and membrane consolidation. Furthermore, from 8 to 10 h after puparium formation (APF) SGs display massive apocrine secretion of a diverse set of cellular proteins. Here, we show that during the period from 11 to 12 h APF, the prepupal glands are very active in calcium oxalate (CaOx) extrusion that resembles renal or nephridial excretory activity. We provide genetic evidence that Prestin, a Drosophila homologue of the mammalian electrogenic anion exchange carrier SLC26A5, is responsible for the instantaneous production of CaOx by the late prepupal SGs. Its positive regulation by the protein kinases encoded by fray and wnk lead to increased production of CaOx. The formation of CaOx appears to be dependent on the cooperation between Prestin and the vATPase complex as treatment with bafilomycin A₁ or concanamycin A abolishes the production of detectable CaOx. These data demonstrate that prepupal SGs remain fully viable, physiologically active and engaged in various cellular activities at least until early pupal period, that is, until moments prior to the execution of PCD.