Fluoxetine treatment abolishes the in vitro respiratory response to acidosis in neonatal mice

International audienceBACKGROUND: To secure pH homeostasis, the central respiratory network must permanently adapt its rhythmic motor drive to environment and behaviour. In neonates, it is commonly admitted that the retrotrapezoid/parafacial respiratory group of neurons of the ventral medulla plays the primary role in the respiratory response to acidosis, although the serotonergic system may also contribute to this response.METHODOLOGY/PRINCIPAL FINDINGS: Using en bloc medullary preparations from neonatal mice, we have shown for the first time that the respiratory response to acidosis is abolished after pre-treatment with the serotonin-transporter blocker fluoxetine (25-50 µM, 20 min), a commonly used antidepressant. Using mRNA in situ hybridization and immunohistology, we have also shown the expression of the serotonin transporter mRNA and serotonin-containing neurons in the vicinity of the RTN/pFRG of neonatal mice.CONCLUSIONS: These results reveal that the serotonergic system plays a pivotal role in pH homeostasis. Although obtained in vitro in neonatal mice, they suggest that drugs targeting the serotonergic system should be used with caution in infants, pregnant women and breastfeeding mothers

Design of Packaging Vents for Cooling Fresh Horticultural Produce

Abstract This review focuses on the design of vents in packages used for handling horticulture produce. The studies on vent designs that are conducted to obtain fundamental understanding of the mechanisms by which different parameters affect the rate and homogeneity of the airflow and the cooling process are presented. Ventilated packages should be designed in such a way that they can provide a uniform airflow distribution and consequently uniform produce cooling. Total opening area and opening size and position show a significant effect on pressure drop, air distribution uniformity and cooling efficiency. Recent advances in measurement and mathematical modelling techniques have provided powerful tools to develop detailed investigations of local airflow rate and heat and mass transfer processes within complex packaging structures. The complexity of the physical structure of the packed systems and the biological variability of the produce make both experimental and model-based studies of transport processes challenging. In many of the available mathematical models, the packed structure is assumed as a porous medium; the limitations of the porous media approach are evident during vented package design studies principally when the containerto-produce dimension ratio is below a certain value. The complex and chaotic structure within horticultural produce ventilated packages during a forced-air precooling process complicates the numerical study of energy and mass transfer considering each individual produce. Future research efforts should be directed to detailed models of the vented package, the complex produce stacking within the package, as well as their interaction with adjacent produce, stacks and surrounding environment. For the validation of the numerical models, the development of better experimental techniques taking into account the complex packaging system is also very important

The process of recovery of people with mental illness: The perspectives of patients, family members and care providers: Part 1

<p>Abstract</p> <p>Background</p> <p>It is a qualitative design study that examines points of divergence and convergence in the perspectives on recovery of 36 participants or 12 triads. Each triad comprising a patient, a family member/friend, a care provider and documents the procedural, analytic of triangulating perspectives as a means of understanding the recovery process which is illustrated by four case studies. Variations are considered as they relate to individual characteristics, type of participant (patient, family, member/friend and care provider), and mental illness. This paper which is part of a larger study and is based on a qualitative research design documents the process of recovery of people with mental illness: Developing a Model of Recovery in Mental Health: A middle range theory.</p> <p><b>Methods</b></p> <p>Data were collected in field notes through semi-structured interviews based on three interview guides (one for patients, one for family members/friends, and one for caregivers). Cross analysis and triangulation methods were used to analyse the areas of convergence and divergence on the recovery process of all triads.</p> <p>Results</p> <p>In general, with the 36 participants united in 12 triads, two themes emerge from the cross-analysis process or triangulation of data sources (12 triads analysis in 12 cases studies). Two themes emerge from the analysis process of the content of 36 interviews with participants: (1) <it>Revealing dynamic context</it>, situating patients in their dynamic context; and (2) <it>Relationship issues in a recovery process</it>, furthering our understanding of such issues. We provide four case studies examples (among 12 cases studies) to illustrate the variations in the way recovery is perceived, interpreted and expressed in relation to the different contexts of interaction.</p> <p>Conclusion</p> <p>The perspectives of the three participants (patients, family members/friends and care providers) suggest that recovery depends on constructing meaning around mental illness experiences and that the process is based on each person's dynamic context (e.g., social network, relationship), life experiences and other social determinants (e.g., symptoms, environment). The findings of this study add to existing knowledge about the determinants of the recovery of persons suffering with a mental illness and significant other utilizing public mental health services in Montreal, Canada.</p

Detecting chilling injury in red delicious apple using hyperspectral imaging and neural networks

a b s t r a c t Hyperspectral imaging (400-1000 nm) and artificial neural network (ANN) techniques were investigated for the detection of chilling injury in Red Delicious apples. A hyperspectral imaging system was established to acquire and pre-process apple images, as well as to extract apple spectral properties. Feed-forward backpropagation ANN models were developed to select the optimal wavelength(s), classify the apples, and detect firmness changes due to chilling injury. The five optimal wavelengths selected by ANN were 717, 751, 875, 960 and 980 nm. The ANN models were trained, tested, and validated using different groups of fruit in order to evaluate the robustness of the models. With the spectral and spatial responses at the selected five optimal wavelengths, an average classification accuracy of 98.4% was achieved for distinguishing between normal and injured fruit. The correlation coefficients between measured and predicted firmness values were 0.93, 0.91 and 0.92 for the training, testing, and validation sets, respectively. These results show the potential of the proposed techniques for detecting chilling injury and predicting apple firmness

Effect of propolis on postharvest control of anthracnose and quality parameters of 'Kent' mango

The objective of this study was to evaluate the efficacy of propolis treatment for reducing anthracnose development on mango fruit of variety Kent; and compare its efficacy to chitosan treatment, which is already a well-studied natural produce. For in vitro experiments, Petri plates were amended with (0, 0.5,1.0, 1.5, 2.0 and 2.5% v/v) propolis or (0, 0.25, 0.5, 1.0, 1.5 and 2.0% w/v) chitosan solutions. For the in vivo experiments, mangoes were infected with a spore suspension of Colletotrichum gloeosporioides and solution of either propolis (1.5%) or chitosan (1.5%) were used for controlling the pathogen development. The fruits were stored for 14 days at 12 ± 1°C and 83 ± 2%RH, and then, for another 7 days at 23?C, 82%. Lesion area, firmness, chemical composition, as well as color of the skin were used for evaluating and compare the performance of the two products. Even if the in vitro results demonstrated the net superiority of propolis for controlling the development of the pathogen, the in vitro results showed the opposite order when classifying the performance of the products with alive fresh produce. The results obtained suggested that propolis, as well as chitosan, may be used as treatment for controlling anthracnose, maintaining quality, and increasing the shelf life in 'Kent' mango. However, propolis was far from producing competitive results to chitosan treatment performance. (Résumé d'auteur

SERT mRNA and 5-HT-containing neurons in the vicinity of the RTN/pFRG of neonatal mice.

<p>A: Two serial coronal sections passing through the RTN/PFRG area of a neonatal mouse show SERT mRNA expression (A1) and Cresyl Violet staining (A2). Anatomical limits drawn from A2 Cresyl Violet section have been superimposed on A1 section (dotted line). Note SERT mRNA is expressed in three areas, the median Raphe Magnus (Rm), the para-pyramidal group (ppy) lateral to the pyramid tract (py) and a lateral spot (arrow) located in a medio-ventral position from the facial motor nucleus (n7), as defined from Cresyl Violet staining (in A2). B- 5-HT neurons in the RTN/pFRG area of a neonatal mouse. Note 5-HT neurons in the median raphe magnus (Rm), the parapyramidal group (ppy, doted circle) lateral to the pyramidal tract (py) and the lateral spot (arrow in B1) in the medio-ventral location of the facial nucleus (n7). In B2 and B3, note the superficial location of some 5-HT neurons (arrows). B3 is an enlargement of B1.</p

Acidosis increases the phrenic burst frequency of en bloc medullary preparations.

<p>A – Schematic presentation of the <i>en bloc</i> preparation of neonatal mice (A1) and example of raw and integrated phrenic bursts (bottom and top traces, respectively) produced by the isolated respiratory rhythm generator (RRG) on the C4 ventral roots of <i>en bloc</i> preparations (A2). B – Columns of the histogram show the mean (and SEM) phrenic burst frequency (PBf; expressed as % of the control PBf) measured every min (one column  = 1 min) in 12 <i>en bloc</i> preparations when the control aCSF(7.4) (white columns) superfusing the preparations was replaced by aCSF(7.1) for 5 min (black columns). Note that acidosis significantly increased the PBf (asterisks indicate a p<0.05 statistical difference). C- As in B but aCSF(7.1) application for 10 min to 6 other preparations. Note that the PBf reached a plateau from the 5^th to the 10^th min of aCSF(7.1) application.</p

Fluoxetine and serotonin pre-treatments abolish the increase of phrenic burst frequency induced by acidosis.

<p><b>A</b> - Columns of the histogram show the mean (and SEM) PBf (expressed as % of the control PBf) measured every min (one column  = 1 min) in 10 preparations when the control aCSF(7.4) (white columns) superfusing the preparations was first replaced by aCSF(7.4) containing fluoxetine (10–25 µM) for 20 min to block the serotonin transporter SERT (grey columns) and thereafter by aCSF(7.1) containing the same amount of fluoxetine for 5 min (black columns). Note that pre-treatment with fluoxetine did not significantly increase the PBf but abolished the PBf increase under acidosis. <b>B</b> - PBf changes (expressed as % of control) every min (one column) but for 14 preparations superfused with control aCSF(7.4) (white columns), aCSF(7.4) containing serotonin, 5-HT (1–5 µM) for 20 min (grey columns) and thereafter aCSF(7.1) containing the same amount of 5-HT for 5 min (black columns). Note that pre-treatment with 5-HT significantly increased the PBf by about 50% and, similarly to fluoxetine treatment, abolished the PBf increase under acidosis.</p