High-purified cannabidiol efficacy and safety in a cohort of adult patients with various types of drug-resistant epilepsies

About 30% of patients with epilepsy are drug resistant. Lennox-Gastaut syndrome (LGS), Dravet syndrome (DS) and tuberous sclerosis complex (TSC) are diseases for which high-purified-cannabidiol (CBD) known as Epidiolex® (GW pharma) can be prescribed in add-on of other medications in case of drug-resistance. Currently, there are only a few recent data in the literature about the efficacy and safety of CBD in other forms of refractory epilepsies especially focal epilepsies in adults. We report retrospectively the experience of high-purified-CBD use in two French reference medical centers for epilepsy in various forms of drug-resistant epilepsy. We distinguished two groups of patients: group A with epileptic encephalopathies and group B with focal or multifocal epilepsy. Safety and efficacy (% of responder patients) were evaluated. Finally, 73 patients (51 in group A and 22 in group B) used high-purified CBD as an add-on treatment for their drug-resistant epilepsy. Patients in group A were significantly younger (P=0.0155), with a longer exposition of treatment (P=0.0497) than group B and with higher doses (P=0.0300). Respectively, 15 patients (29.4%) and five patients (22.7%) were responders during the follow-up period (P=0.552). The association with clobazam was more frequent in responders than in non-responder patients (16 patients [80%] versus four [20%]). The most frequent side effect was somnolence. At the end of follow-up, 15 patients in group A (29.4%) and nine patients in group B (40.1%) had stopped the high-purified-CBD treatment due to aggravation of seizure, absence of positive effects, or adverse events. This study showed no significant difference regarding the type of drug-resistant epilepsy and suggests that this treatment may be of interest for all types of drug-resistant epilepsy.

[French practical guidelines for the diagnosis and management of IPF - 2021 update, full version]

BACKGROUND

Since the previous French guidelines were published in 2017, substantial additional knowledge about idiopathic pulmonary fibrosis has accumulated.

METHODS

Under the auspices of the French-speaking Learned Society of Pulmonology and at the initiative of the coordinating reference center, practical guidelines for treatment of rare pulmonary diseases have been established. They were elaborated by groups of writers, reviewers and coordinators with the help of the OrphaLung network, as well as pulmonologists with varying practice modalities, radiologists, pathologists, a general practitioner, a head nurse, and a patients' association. The method was developed according to rules entitled "Good clinical practice" in the overall framework of the "Guidelines for clinical practice" of the official French health authority (HAS), taking into account the results of an online vote using a Likert scale.

RESULTS

After analysis of the literature, 54 recommendations were formulated, improved, and validated by the working groups. The recommendations covered a wide-ranging aspects of the disease and its treatment: epidemiology, diagnostic modalities, quality criteria and interpretation of chest CT, indication and modalities of lung biopsy, etiologic workup, approach to familial disease entailing indications and modalities of genetic testing, evaluation of possible functional impairments and prognosis, indications for and use of antifibrotic therapy, lung transplantation, symptom management, comorbidities and complications, treatment of chronic respiratory failure, diagnosis and management of acute exacerbations of fibrosis.

CONCLUSION

These evidence-based guidelines are aimed at guiding the diagnosis and the management in clinical practice of idiopathic pulmonary fibrosis.

Multi-tracer and multiparametric PET imaging to detect the IDH mutation in glioma: a preclinical translational in vitro, in vivo, and ex vivo study

Background

This translational study explores multi-tracer PET imaging for the non-invasive detection of the IDH1 mutation which is a positive prognostic factor in glioma.

Methods

U87 human high-grade glioma (HGG) isogenic cell lines with or without the IDH1 mutation (CRISP/Cas9 method) were stereotactically grafted into rat brains, and examined, in vitro, in vivo and ex vivo. PET imaging sessions, with radiotracers specific for glycolytic metabolism ([¹⁸F]FDG), amino acid metabolism ([¹⁸F]FDopa), and inflammation ([¹⁸F]DPA-714), were performed sequentially during 3–4 days. The in vitro radiotracer uptake was expressed as percent per million cells. For each radiotracer examined in vivo, static analyses included the maximal and mean tumor-to-background ratio (TBR_max and TBR_mean) and metabolic tumor volume (MTV). Dynamic analyses included the distribution volume ratio (DVR) and the relative residence time (RRT) extracted from a reference Logan model. Ex vivo analyses consisted of immunological analyses.

Results

In vitro, IDH1+ cells (i.e. cells expressing the IDH1 mutation) showed lower levels of [¹⁸F]DPA-714 uptake compared to IDH1- cells (p < 0.01). These results were confirmed in vivo with lower [¹⁸F]DPA-714 uptake in IDH+ tumors (3.90 versus 5.52 for TBR_max, p = 0.03). Different values of [¹⁸F]DPA-714 and [¹⁸F] FDopa RRT (respectively 11.07 versus 22.33 and 2.69 versus − 1.81 for IDH+ and IDH- tumors, p < 0.02) were also observed between the two types of tumors. RRT [¹⁸F]DPA-714 provided the best diagnostic performance to discriminate between the two cell lines (AUC of 100%, p < 0.01). Immuno-histological analyses revealed lower expression of Iba-1 and TSPO antibodies in IDH1+ tumors.

Conclusions

[18F]DPA-714 and [18F] FDopa both correlate with the presence of the IDH1 mutation in HGG. These radiotracers are therefore good candidates for translational studies investigating their clinical applications in patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40644-022-00454-6.

[French practical guidelines for the diagnosis and management of IPF - 2021 update, short version]

BACKGROUND

Since the previous French guidelines were published in 2017, substantial additional knowledge about idiopathic pulmonary fibrosis has accumulated.

METHODS

Under the auspices of the French-speaking Learned Society of Pulmonology and at the initiative of the coordinating reference center, practical guidelines for treatment of rare pulmonary diseases have been established. They were elaborated by groups of writers, reviewers and coordinators with the help of the OrphaLung network, as well as pulmonologists with varying practice modalities, radiologists, pathologists, a general practitioner, a head nurse, and a patients' association. The method was developed according to rules entitled "Good clinical practice" in the overall framework of the "Guidelines for clinical practice" of the official French health authority (HAS), taking into account the results of an online vote using a Likert scale.

RESULTS

After analysis of the literature, 54 recommendations were formulated, improved, and validated by the working groups. The recommendations covered a wide-ranging aspects of the disease and its treatment: epidemiology, diagnostic modalities, quality criteria and interpretation of chest CT, indication and modalities of lung biopsy, etiologic workup, approach to familial disease entailing indications and modalities of genetic testing, evaluation of possible functional impairments and prognosis, indications for and use of antifibrotic therapy, lung transplantation, symptom management, comorbidities and complications, treatment of chronic respiratory failure, diagnosis and management of acute exacerbations of fibrosis.

CONCLUSION

These evidence-based guidelines are aimed at guiding the diagnosis and the management in clinical practice of idiopathic pulmonary fibrosis.

In vivo characterization of physiological and metabolic changes related to isocitrate dehydrogenase 1 mutation expcression by multiparametric MRI and MRS in a rat model with orthotopically grafted human-derived glioblastoma cell lines

The physiological mechanism induced by the isocitrate dehydrogenase 1 (IDH1) mutation, associated with better treatment response in gliomas, remains unknown. The aim of this preclinical study was to characterize the IDH1 mutation through in vivo multiparametric MRI and MRS. Multiparametric MRI, including the measurement of blood flow, vascularity, oxygenation, permeability, and in vivo MRS, was performed on a 4.7 T animal MRI system in rat brains grafted with human-derived glioblastoma U87 cell lines expressing or not the IDH1 mutation by the CRISPR/Cas9 method, and secondarily characterized with additional ex vivo HR-MAS and histological analyses. In univariate analyses, compared with IDH1-, IDH1+ tumors exhibited higher vascular density (p < 0.01) and better perfusion (p = 0.02 for cerebral blood flow), but lower vessel permeability (p < 0.01 for time to peak (TTP), p = 0.04 for contrast enhancement) and decreased T1 map values (p = 0.02). Using linear discriminant analysis, vascular density and TTP values were found to be independent MRI parameters for characterizing the IDH1 mutation (p < 0.01). In vivo MRS and ex vivo HR-MAS analysis showed lower metabolites of tumor aggressiveness for IDH1+ tumors (p < 0.01). Overall, the IDH1 mutation exhibited a higher vascularity on MRI, a lower permeability, and a less aggressive metabolic profile. These MRI features may prove helpful to better pinpoint the physiological mechanisms induced by this mutation.

Modelling the precipitation of nanoparticles in a closed medium in the presence of seeds: Application to amorphous silica synthesis

Seed-mediated methods are widely used in industrial or academic laboratories for the synthesis of nanoparticles of controlled shape and size. In the natural medium, precipitation of secondary minerals also often take place on seeds. In this context, we have devised a formalism which accounts for the competition between seed growth and nucleation and growth of secondary particles in an initially over-saturated aqueous solution. Based on the classical nucleation theory, it involves a size-dependent growth law which accounts for Ostwald ripening effects, unlike most water-rock interaction codes. We find that, in such closed system, seed growth and nucleation/growth of secondary particles are strongly coupled. In the multi-dimensional parameter space, regions where one or the other process prevails are well-separated by a rather abrupt transition. In general, the value of the initial seed total surface area is insufficient to fully orientate the synthesis. Relying on this approach, we propose an alternative interpretation of recent experimental results on amorphous silica nanoparticle synthesis. Besides fundamental understanding of the kinetics of precipitation, the interest of the present approach is to serve as a guideline to experimentalists or industrialists working in seed-mediated syntheses and warn on the undesired formation of secondary particles when monodispersed distributions of nano- or micro-particles are searched.

A 1-week extension of a ketogenic diet provides a further decrease in myocardial 18F-FDG uptake and a high detectability of myocarditis with FDG-PET

BACKGROUND

Short periods of fasting and/or low-carbohydrate diet have been proven beneficial for decreasing the myocardial uptake of 18F-fluorodeoxyglucose (18F-FDG) and enhancing the detection of inflammatory heart diseases by 18F-FDG positron emission tomography (PET). This study aimed at determining whether this benefit is increased when a low-carbohydrate ketogenic diet is prolonged up to 7 days.

METHODS

Wistar rats underwent serial 18F-FDG-PET imaging after an 18-hour fasting period and after 2, 4 and 7 days of a ketogenic diet (3% carbohydrate) and they were compared to rats submitted to the same protocol but with normal diet (44% carbohydrate). The 18F-FDG-PET/ketogenic protocol was also applied in rats with immune myocarditis (injection of porcine cardiac myosin).

RESULTS

The 7-day ketogenic diet was associated with (1) a sustained increase in circulating ketone bodies at an equivalent level to that reached after 18-hour fasting, (2) a gradual decrease in 18F-FDG uptake within normal myocardium reaching a lower level compared to fasting at the 7th day (myocardium-to-blood ratios: 1.68 ± 1.02 vs 3.25 ± 1.40, P < .05) and (3) a high 18F-FDG-PET detectability of myocarditis areas.

CONCLUSION

One-week extension of a ketogenic diet provides a further decrease in the 18F-FDG uptake of normal myocardium and a high detectability of inflammatory areas.

[Importance of the determination of MTHFR SNPs (Methylene Tetrahydrofolate Reductase Single Nucleotide Polymorphisms) in couple infertility]

OBJECTIVE

MTHFR SNPs (Methylene Tetrahydrofolate reductase Single Nucleotide polymorphisms) are biochemical modifications decreasing the capacity to form 5 MTHF 5 methyltetrahydrofolate (5MTHF). Their presence reduces the capacity of the One Carbon cycle, and so the regeneration of Homocysteine (Hcy) and in fine strongly perturbs all the methylation processes. As methylation processes are major regulators in gametogenesis and embryogenesis. We have determined the prevalence of the 2 most important SNPs A1298C and C677T in our population of patients consulting for infertility.

METHODS

Determination of the MTHFR SNPs A1298C and C677T, by hybridization using the LAMP Human MTHFR mutation KITs.

RESULTS

Only 15.8% of our patients (861) do not carry any SNP (WT wid type). Close to 20% of the patients are homozygotes for one mutation or the other. A total of 19.7% are composite heterozygous. A total of 43% of our population is considered "at risk", based on observations collected for the repeat miscarriages.

CONCLUSIONS

Determination of the 2 major MTHFR SNPs is not a "first row" choice, but it must not be neglected and should be carried out in case of repeat ART failures and repeat miscarriages. Some simple therapeutic options can be proposed: they are based on the use of 5MTHF (5MethyleneTetraHydroFolate) the compound downstream the MTHFR.

Control of the mobilization of arsenic and other natural pollutants in groundwater by calcium carbonate concretions in the Pampean Aquifer, southeast of the Buenos Aires province, Argentina

The water supply for human consumption in the Chaco-Pampean region in Argentina is restricted by the low quality of groundwater due to elevated concentrations of arsenic and other trace elements. Previous studies indicated a complex concurrence of factors and processes that are believed responsible to control the distribution of arsenic in groundwater. For a better understanding of the origin of trace elements in the Pampean aquifer, flow-through experiments with loess and calcrete samples representative of the sediments that constitute the aquifer were carried out in continuous flow reactors. The aqueous solutions were collected and the concentrations of SiO₂(aq), Ca²⁺, SO₄^2-, Na⁺, Cl^-, F^- and trace elements (Ba, Sr, V, and As) were measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES), high performance liquid chromatography (HPLC) and capillary electrophoresis. The experiments showed differences in the release rate of elements to the solution according to the type of sediment. The highest concentrations of V, Ba, and As were measured in experiments conducted with loess, and these elements were released quickly to the solution in the first minute of the test. In the case of loess, V and As are suggested to be adsorbed on the solid particles surface. Conversely, the experiments conducted with calcrete showed a lower but continuous release of those elements. This last result may indicate that the trace elements were coprecipitated in the calcite. In addition, it was demonstrated that F did not come from the dissolution of minerals such as fluorapatite, but both desorption from solid surface and dissolution from calcite minerals account for the release of F. This study support that both dissolution and adsorption-desorption processes can control the mobility of trace elements, with an emphasis on the role of calcrete in the retention and the mobilization of trace elements in the Pampean aquifer.

SFSPM 2018 — Congrès de la Société Française de Sénologie et de Pathologie Mammaire (Avignon, 7-9/11-2018)

Les 40es Journées de la SFSPM se sont tenues à Avignon du 7 au 9 novembre 2018. Le thème abordé—Cancer du sein : optimisation du parcours de soins — a réuni plus de 1 200 participants sous les voûtes du Palais des Papes. La fluidité de chaque segment du parcours a été analysée en termes de risques de rupture de continuité des soins tant au sein du segment lui-même qu’en amont et en aval. Dans un parcours par essence pluridisciplinaire et plurimétiers, la nécessité d’une réflexion globale et d’une coordination active réalisées par des professionnels formés a été rappelée à chaque session. Chacun des intervenants a esquissé de potentiels indicateurs de qualité tenant compte à la fois de son implication dans son segment d’intervention, mais tenant compte aussi d’une vision plus globale de ce que devrait être le parcours au travers de la maladie et des soins. La parole a été très largement partagée entre soignants et associations de malades, entre paramédicaux et acteurs en sciences humaines et sociales, entre responsables de la santé publique HAS, ARS, CNAM–CPAM 84 et représentants des différents modes d’hospitalisation publique/privée et ESPIC. La session grand public a été l’occasion d’échanges fructueux et instructifs sur la perception des difficultés comme des satisfactions rencontrées que nous ont fait partager les malades, leurs proches et les représentantes des associations. Au total, un congrès de réflexion partagé par de nombreux acteurs qui cherchent tous à améliorer le parcours de soins des malades atteintes de cancer du sein. La publication le 21 janvier par l’INCa de dix indicateurs de qualité du parcours de soins pour les malades atteints de cancer du sein est une étape importante qu’attendaient tous les participants d’Avignon — SFSPM 2018.

The mitochondrial DNA content of cumulus granulosa cells is linked to embryo quality

STUDY QUESTION

Could the mitochondrial DNA (mtDNA) content of cumulus granulosa cells (CGCs) be related to oocyte competence?

SUMMARY ANSWER

The quality of embryos obtained during IVF procedures appears to be linked to mtDNA copy numbers in the CGCs.

WHAT IS KNOWN ALREADY

Oocyte quality is linked to oocyte mtDNA content in the human and other species, and the mtDNA copy number of the oocyte is related to that of the corresponding CGCs. Moreover, the quantification of CGC mtDNA has recently been proposed as a biomarker of embryo viability.

STUDY DESIGN SIZE, DURATION

An observational study was performed on 452 oocyte-cumulus complexes retrieved from 62 patients undergoing ICSI at the ART Center of the University Hospital of Angers, France, from January to May 2015.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The average mtDNA content of CGCs was assessed by using a quantitative real-time PCR technique. The relationship between CGC mtDNA content and oocyte maturity and fertilizability, on one hand, and embryo quality, on the other, was investigated using univariate and multivariate generalized models with fixed and mixed effects.

MAIN RESULTS AND THE ROLE OF CHANCE

No relationship was found between CGC mtDNA content and oocyte maturity or fertilizability. In contrast, there was a significant link between the content of mtDNA in CGCs surrounding an oocyte and the embryo quality, with significantly higher mtDNA copy numbers being associated with good quality embryos compared with fair or poor quality embryos [interquartile range, respectively, 738 (250-1228) and 342 (159-818); P = 0.006]. However, the indication provided by the quantification of CGC mtDNA concerning the eventuality of good embryo quality was seriously subject to patient effect (AUC = 0.806, 95%CI = 0.719-0.869). The quantity of CGC mtDNA was influenced by BMI and smoking.

LARGE SCALE DATA

N/A.

LIMITATIONS REASONS FOR CAUTION

The quantification of CGC mtDNA may indicate embryo quality. However, since it is affected by patient specificity, it should be used with caution. It remains to be seen whether this marker could directly predict the implantation capacity of the embryo, which is the main objective in IVF practice.

WIDER IMPLICATIONS OF THE FINDINGS

Our study suggests that the quantification of CGC mtDNA may be a novel biomarker of embryo viability. However, patient specificity makes it impossible to establish a general threshold value, valid for all patients. Nevertheless, further studies are needed to determine whether the quantification of CGC mtDNA may, in combination with the morpho-kinetic method, offer an additional criterion for selecting the best embryo for transfer from a given cohort.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the University Hospital of Angers, the University of Angers, France, and the French national research centres INSERM and the CNRS. There were no competing interests.

Zebrafish models of human eye and inner ear diseases

Eye and inner ear diseases are the most common sensory impairments that greatly impact quality of life. Zebrafish have been intensively employed to understand the fundamental mechanisms underlying eye and inner ear development. The zebrafish visual and vestibulo-acoustic systems are very similar to these in humans, and although not yet mature, they are functional by 5days post-fertilization (dpf). In this chapter, we show how the zebrafish has significantly contributed to the field of biomedical research and how researchers, by establishing disease models and meticulously characterizing their phenotypes, have taken the first steps toward therapies. We review here models for (1) eye diseases, (2) ear diseases, and (3) syndromes affecting eye and/or ear. The use of new genome editing technologies and high-throughput screening systems should increase considerably the speed at which knowledge from zebrafish disease models is acquired, opening avenues for better diagnostics, treatments, and therapies.

Precipitation mechanism of amorphous silica nanoparticles: a simulation approach

HYPOTHESIS

Despite its importance in numerous industrial and natural processes, many unsolved questions remain regarding the mechanism of silica precipitation in aqueous solutions: order of the reaction, role of silica oligomers, existence of an induction time and characteristics of the particle population. This may be traced back, in past models, to the lack of account of the first stages of nucleation, size dependence of the growth law, and full particle population. COMPUTATIONAL METHOD: A microscopic description of the nucleation and growth of amorphous silica nanoparticles is achieved which reproduces a large set of experimental measurements, under various thermodynamic conditions. The time evolution of the solution supersaturation and of the precipitate characteristics is established.

FINDINGS

A growth law of order 6 allows reproducing experimental results, without being correlated to the presence of silica oligomers in the aqueous solution. The saturation plateaus are shown not to be due to an induction period. The characteristics of the particle population are more complex than assumed by simple precipitation models (Johnson-Mehl-Avrami-Kolmogorov or Chronomal models) and strongly depend on how supersaturation is reached. Such a microscopic approach thus proves to be well suited to elucidate the mechanism of nanoparticle formation in natural and industrial contexts.

Identification and description of the axillary web syndrome (AWS) by clinical signs, MRI and US imaging

The Axillary Web Syndrome (AWS) follows surgery for breast neoplasia and consists of one, or more frequently two or three, cords of subcutaneous tissue. Cords originate from the axilla, spread to the antero-medial surface of the arm down to the elbow and then move into the antero-medial aspect of the forearm and sometimes into the root of the thumb. The purpose of this study was to compare two techniques, ultrasound (US) and Magnetic Resonance Imaging (MRI) for their sensitivity and accuracy in identifying AWS cords and to provide insights to the origin of this pathology. US examinations were performed on fifteen patients using a high frequency probe (17 MHz). We first palpated and marked the cord with location aided by maximum abduction. To identify the cord with MRI (1.5 Tesla), a catheter filled with a gel detectable under MRI was placed on the skin at the site of the cord. We found that in some US cases, the dynamic abduction maneuver was essential to facilitate detection of the cord. This dynamic method on ultrasound confirmed the precise location of the cord even if it was located deeper in the hypodermis fascia junction. US and MRI images revealed features of the cords and surrounding tissues. Imaging the cords was difficult with either of the imaging modalities. However, US seemed to be more efficient than MRI and allowed dynamic evaluation. Overall analysis of our study results supports a lymphatic origin of the AWS cord.

Phosphate-induced mineralization of tracheal smooth muscle and cartilage cells

BACKGROUND

During aging or various diseases, pathologic mineralization may occur in joints or in the vascular wall. This is due to the deposition of phosphate (Pi)-containing crystals into the extracellular matrix of articular chondrocytes or vascular smooth muscle cells. The mineralization ability of chondrocytes and smooth muscle cells of other tissue has not been investigated.

OBJECTIVE

In this context, our work seeks to study the response induced by Pi on cartilage and smooth muscle cells from tracheal origin.

METHODS

We have established a dissection procedure to harvest and isolate chondrocyte and smooth muscle cells from adult mouse trachea. Both cell types were then exposed to different concentrations of Pi (1, 3 or 5 mM) up to 14 days. Mineralization was evaluated by alizarin red staining, which identifies calcium deposition. The expression of genes characterizing the phenotypic identity of the cells and involved in the mineralization process was assessed by RT-qPCR.

RESULTS

Treatment of tracheal chondrocytes and smooth muscle cells with increasing concentrations of Pi (3 and 5 mM) induced mineralization as revealed by positive alizarin red staining as early as 7 days of culture. Moreover, gene expression analysis revealed profound phenotypic changes in both cell types and suggested they mineralize through TNAP-independent or -dependent mechanisms, respectively.

CONCLUSIONS

Our data indicate that, comparably to articular chondrocytes or vascular smooth muscles, chondrocyte and smooth muscle cells from the trachea are prone to mineralize under high-phosphate conditions.

Axillary web syndrome: nature and localization

Axillary Web Syndrome (AWS) is a complication that can arise in patients following treatment for breast cancer. It is also known variously as syndrome of the axillary cords, syndrome of the axillary adhesion, and cording lymphedema. The exact origin, presentation, course, and treatment of AWS is still largely undefined. Because so little is known about AWS, we undertook a case series study consisting of 15 women who had undergone breast cancer surgery and presented with AWS. All subjects received a clinical examination which included body size determination and detailed measurements of the size and location of the cords. The cords were found to originate from the axilla, continue on the medial aspect of the arm up to the epitrochlea region, then to the anteromedian aspect of the forearm, and finally reaching the base of the thumb. The cords averaged approximately 44% of the limb length. Correlation of the cord location with anatomical studies shows that in fact this path follows the specific course taken by the antero-radial pedicle which arises at the anterior aspect of the elbow from the brachial medial pedicule to anastomose in the axilla at the level of the lateral thoracic chain nodes. Although our series is small, the correspondence between the physical findings and the anatomical studies strongly supports the notion that the cords are lymphatic in origin.

Carbohydrate storage in wood and bark of rubber trees submitted to different level of C demand induced by latex tapping

When the current level of carbohydrates produced by photosynthesis is not enough to meet the C demand for maintenance, growth or metabolism, trees use stored carbohydrates. In rubber trees (Hevea brasiliensis Muell. Arg.), however, a previous study (Silpi U., A. Lacointe, P. Kasemsap, S. Thanisawanyangkura, P. Chantuma, E. Gohet, N. Musigamart, A. Clement, T. Améglio and P. Thaler. 2007. Carbohydrate reserves as a competing sink: evidence from tapping the rubber tree. Tree Physiol. 27:881-889) showed that the additional sink created by latex tapping results not in a decrease, but in an increase in the non-structural carbohydrate (NSC) storage in trunk wood. In this study, the response of NSC storage to latex tapping was further investigated to better understand the trade-off between latex regeneration, biomass and storage. Three tapping systems were compared to the untapped Control for 2 years. Soluble sugars and starch were analyzed in bark and wood on both sides of the trunk, from 50 to 200 cm from the ground. The results confirmed over the 2 years that tapped trees stored more NSC, mainly starch, than untapped Control. Moreover, a double cut alternative tapping system, which produced a higher latex yield than conventional systems, led to even higher NSC concentrations. In all tapped trees, the increase in storage occurred together with a reduction in trunk radial growth. This was interpreted as a shift in carbon allocation toward the creation of reserves, at the expense of growth, to cover the increased risk induced by tapping (repeated wounding and loss of C in latex). Starch was lower in bark than in wood, whereas it was the contrary for soluble sugars. The resulting NSC was twice as low and less variable in bark than in wood. Although latex regeneration occurs in the bark, changes related to latex tapping were more marked in wood than in bark. From seasonal dynamics and differences between the two sides of the trunk in response to tapping, we concluded that starch in wood behaved as the long-term reserve compartment at the whole trunk level, whereas starch in bark was a local buffer. Soluble sugars behaved like an intermediate, ready-to-use compartment in both wood and bark. Finally, the dynamics of carbohydrate reserves appears a relevant parameter to assess the long-term performance of latex tapping systems.

Computed tomography findings in urban transportation workers with low cumulative asbestos exposure

OBJECTIVE

To assess the frequency of computed tomography (CT) scan pleural and interstitial changes in a population of urban transportation workers with low cumulative exposure to asbestos, and to measure inter-reader agreement.

DESIGN

A total of 269 male volunteers (mean age 54.0 +/- 2.3 years, mean estimated cumulative exposure index 1.7 +/- 2.3 fibres/ml-years), underwent a CT scan which was read independently by three experienced readers, with further consensus reading in case of pleural or parenchymal abnormalities. Inter-reader agreement was assessed by means of Kappa statistic.

RESULTS

On consensus reading, four subjects had interstitial opacities, three had diffuse pleural thickening and 26 (9.7%) had pleural plaques that were unilateral in 65% of cases and < or =2 mm thick in 54% of cases. No correlation was observed between pleural plaques and latency, duration of exposure or cumulative exposure. The inter-reader agreement for the detection of pleural abnormalities was fair.

CONCLUSION

In this relatively young population with low cumulative exposure to asbestos, the prevalence of pleural abnormalities was low. These abnormalities were very limited in thickness and extent, leading to marked inter-reader variability and making it difficult to assess their relationship to asbestos exposure.

Carbohydrate reserves as a competing sink: evidence from tapping rubber trees

Carbohydrate reserve storage in trees is usually considered a passive function, essentially buffering temporary discrepancies between carbon availability and demand in the annual cycle. Recently, however, the concept has emerged that storage might be a process that competes with other active sinks for assimilate. We tested the validity of this concept in Hevea brasiliensis Müll. Arg. (rubber) trees, a species in which carbon availability can be manipulated by tapping, which induces latex regeneration, a high carbon-cost activity. The annual dynamics of carbohydrate reserves were followed during three situations of decreasing carbon availability: control (no tapping), tapped and tapped with Ethephon stimulation. In untapped control trees, starch and sucrose were the main carbohydrate compounds. Total nonstructural carbohydrates (TNC), particularly starch, were depleted following bud break and re-foliation, resulting in an acropetal gradient of decreasing starch concentration in the stem wood. During the vegetative season, TNC concentration increased. At the end of the vegetative season, there were almost no differences in TNC concentration along the trunk. In tapped trees, the vertical gradient of starch concentration was locally disturbed by the presence of the tapping cut. However, the main effect of tapping was a dramatic increase in TNC concentration, particularly starch, throughout the trunk and in the root. The difference in TNC concentration between tapped and untapped trees was highest when latex production was highest (October); the difference was noticeable even in areas of the trees that are unlikely to be directly involved in latex regeneration, and it was enhanced by Ethephon stimulation, which is known to increase latex metabolism and flow duration. Thus, contrary to what could be expected if reserves serve as a passive buffer, a decrease in carbohydrate availability resulted in a net increase in carbohydrate reserves at the trunk scale. Such behavior supports the view that trees tend to adjust the amount of carbohydrate reserves stored to the level of metabolic demand, at the possible expense of growth.

Respiratory-related evoked potentials in children with asthma

AIMS OF THE STUDY

Respiratory-related evoked potentials (RREPs) are a method of recording brain activities in response to respiratory stimuli. Although data in childhood are scarce, the absence of the early P1 component of RREPs has been reported in children with a history of life-threatening asthma. This study was focused on the presence, latencies, and amplitudes of the P1, N1, P2, and N2 components of the RREPs in a paediatric series of asthmatic patients.

PATIENTS AND METHODS

RREPs were recorded in 21 patients with stable asthma, age range 8-17 years, 11 healthy children, age range 6-16 years, and 24 healthy adults, age range 20-28 years. The signals from left (C3-Cz) and right (C4-Cz) central (rolandic) location were recorded separately, using surface electrodes. Evoked responses to two series of 80 consecutive mid-inspiratory occlusions were averaged. Recordings were analysed manually.

RESULTS

All 4 RREPs components were significantly more often absent in asthmatic children than in healthy children and adults (P1, p=0.01; N1, p=0.008; P2, p=0.008, N2, p=0.01). The latencies and amplitudes of the four components were similar in patients and healthy subjects.

CONCLUSION

RREPs components were less frequently present in children with asthma than in healthy subjects. This finding should promote the recording of RREPs in other acute and chronic respiratory diseases in children in order to search for possible electroclinical correlations.

Counting in a time discrimination task in children and adults

The present study investigated in 5- and 8-year-olds, as well as in adults, the effect of verbal counting on temporal discrimination behavior in a generalization task with two duration ranges in order to test the scalar timing property. The results showed that counting improved temporal sensitivity in all age groups, although sensitivity to time remained lower in the younger children. Furthermore, in the 5-year-olds, the temporal generalization behavior conformed well to the scalar property of variance both in the counting and the non-counting condition. However, this conformity to the scalar timing property disappeared when counting was used in the 8-year-olds and the adults. The development of the ability to count time at a constant rhythm is discussed as the major reason for this departure of temporal behavior from the scalar property of variance when counting is employed.

RPGR is mutated in patients with a complex X linked phenotype combining primary ciliary dyskinesia and retinitis pigmentosa

INTRODUCTION

Primary ciliary dyskinesia (PCD) is a rare disease classically transmitted as an autosomal recessive trait and characterised by recurrent airway infections due to abnormal ciliary structure and function. To date, only two autosomal genes, DNAI1 and DNAH5 encoding axonemal dynein chains, have been shown to cause PCD with defective outer dynein arms. Here, we investigated one non-consanguineous family in which a woman with retinitis pigmentosa (RP) gave birth to two boys with a complex phenotype combining PCD, discovered in early childhood and characterised by partial dynein arm defects, and RP that occurred secondarily. The family history prompted us to search for an X linked gene that could account for both conditions.

RESULTS

We found perfect segregation of the disease phenotype with RP3 associated markers (Xp21.1). Analysis of the retinitis pigmentosa GTPase regulator gene (RPGR) located at this locus revealed a mutation (631_IVS6+9del) in the two boys and their mother. As shown by study of RPGR transcripts expressed in nasal epithelial cells, this intragenic deletion, which leads to activation of a cryptic donor splice site, predicts a severely truncated protein.

CONCLUSION

These data provide the first clear demonstration of X linked transmission of PCD. This unusual mode of inheritance of PCD in patients with particular phenotypic features (that is, partial dynein arm defects and association with RP), which should modify the current management of families affected by PCD or RP, unveils the importance of RPGR in the proper development of both respiratory ciliary structures and connecting cilia of photoreceptors.

Setting of noninvasive pressure support in young patients with cystic fibrosis

The aim of the current study was to compare a clinical noninvasive method of setting up noninvasive pressure support ventilation (PS-NI) in young patients with cystic fibrosis (CF), based on parameters such as breathing frequency, arterial oxygen saturation and comfort rating, with a more invasive method (PS-I) targeted at optimising unloading of the inspiratory muscles and enhancing patient-ventilator synchronisation. PS-NI and PS-I were compared in random order in 10 children with CF. PS-NI differed from PS-I with regard to the level of inspiratory pressure (n=5), rate of inspiratory pressurisation (n=1), inspiratory trigger sensitivity (n=2) and expiratory trigger sensitivity (n=5). Although both methods modified breathing pattern, improved oxygen saturation and reduced diaphragmatic pressure time product (450+/-91 cmH2O.s(-1).min(-1) during spontaneous breathing, and 129+/-125 and 104+/-75 cmH2O.s(-1).min(-1) during PS-NI and PS-I, respectively), patient-ventilator synchrony and patient comfort were enhanced more during PS-I. In young patients with cystic fibrosis, setting up pressure support using a clinical noninvasive approach based on easily measurable parameters, such as respiratory rate and comfort rating, is as effective as a more invasive technique based on unloading of the inspiratory muscles and optimising patient-ventilator synchronisation. However, whilst the standard clinical method is satisfactory in the majority of patients, more invasive measurements should be considered in patients who have difficulty synchronising with the ventilator to enhance patient tolerance and compliance.

Shortening the VSP-A: Preliminary development of the VSP-A12, a 12-item short-form

The 'Vécu et Santé Perçue des Adolescents' (VSP-A) questionnaire is a French generic self-administered health-related quality of life (HRQL) instrument for adolescents which comprises 40 items, allowing the calculation of six dimensions as well as an index. Regression methods were used to select 12 items from the VSP-A to reproduce its HRQL index. The resulting 12-item short-form (VSP-A12) achieved an adjusted R2 of 0.907 in prediction of the VSP-A index. Scoring algorithm used to score this 12-item index achieved a R2 of 0.901 with the VSP-A index when cross-validated in the validation sample (n = 2941). Numerous tests of empirical validity previously published for the VSP-A were replicated for the VSP-A12, including comparisons between groups known to differ in terms of gender, age or health status. All the significant results shown by the VSP-A index were also encountered by the VSP-A12 summary measure. The ability of VSP-A12 to discriminate between healthy and ill adolescents was also proven. A test-retest correlation (4 weeks) of 0.745 was observed for the 12-item HRQL index in the target population (n = 664). Average score for this shorter index closely mirrored VSP-A index, although standard deviation was always greater for the VSP-A12.

[Diseases of the pulmonary lymphatic system in children]

Diseases of the lymphatic system in children include a group of exceptional conditions difficult to manage. The anatomy of lymphatic system is complex in the lung. Variable from one subject to another, its complex physiology plays an important role in air-blood exchanges occurring in the lung. In the pulmonary interstitium and in the pleura, the lymphatic system acts like an overflow valve capable of regulating variations in interstitial fluid. The presence or development of dysplasic lymphatics causes leakage, dilatation, and reflux of the lymph through incontinent valves leading to chylothorax and/or fluid overload in the pulmonary interstitium. Symptomatic care is usually proposed, based on a fat-free diet supplemented with light-chain triglycerides and liposoluble vitamins. Other therapeutic options can be proposed. Medical options include cytotoxic agents, somatostatin, and interferon-alpha. Surgery may also be useful, but an assessment of therapeutic efficacy is very difficult due to partial effects and the small number of cases studied.