Microscopic imaging as a tool to target spatial and temporal extraction of bioactive compounds through ultrasound intensification.

Unravelling a chain of events in ultrasound-assisted extraction (UAE) of bioactive compounds from plants has to start with a detailed description of destructuration at macroscopic and microscopic scale. The present work aims to study the impacts and interactions of UAE on the extreme complexity and diversity of plants structures. Three plant species were selected for their difference in specialized structures and their spatial distribution of secondary metabolites: bitter orange leaf (C. aurantium L.), blackcurrant leaf (R. nigrum L.), and artichoke leaf (C. scolymus L.). Different microscopic techniques (Cyto-histochemistry, stereomicroscopic analysis, Scanning Electron Microscopy (SEM)) have been used to understand the complexity of plant structures and to highlight ultrasound-induced impacts especially on metabolites storage structures, with a neat comparison with conventional "silent" extraction procedure. The main results indicate that spatial UAE impacts are strongly related to plant structures' properties (morphology, thickness, etc.) and particularly to the nature and the chemical constitution of their storage specialized structures. From a temporal point of view, for all studied leaves, observed mechanisms followed a special order according to structures and their mechanical resistance level to ultrasound (US) treatment. Microscopic mapping of metabolites and structures should be considered as a decision tool during UAE to target intensification process.

Correction: Interleukin-22-deficiency and microbiota contribute to the exacerbation of Toxoplasma gondii-induced intestinal inflammation.

The original version of this Article omitted the author Dr Mathias Chamaillard from the l'Institut de Pasteur, Lille, France. This has been corrected in both the PDF and HTML versions of the Article.

Interleukin-22-deficiency and microbiota contribute to the exacerbation of Toxoplasma gondii-induced intestinal inflammation.

Upon oral infection with Toxoplasma gondii cysts (76 K strain) tachyzoites are released into the intestinal lumen and cross the epithelial barrier causing damage and acute intestinal inflammation in C57BL/6 (B6) mice. Here we investigated the role of microbiota and IL-22 in T.gondii-induced small intestinal inflammation. Oral T.gondii infection in B6 mice causes inflammation with IFNγ and IL-22 production. In IL-22-deficient mice, T.gondii infection augments the Th1 driven inflammation. Deficiency in either IL-22bp, the soluble IL-22 receptor or Reg3γ, an IL-22-dependent antimicrobial lectin/peptide, did not reduce inflammation. Under germ-free conditions, T.gondii-induced inflammation was reduced in correlation with parasite load. But intestinal inflammation is still present in germ-free mice, at low level, in the lamina propria, independently of IL-22 expression. Exacerbated intestinal inflammation driven by absence of IL-22 appears to be independent of IL-22 deficiency associated-dysbiosis as similar inflammation was observed after fecal transplantation of IL-22-/- or WT microbiota to germ-free-WT mice. Our results suggest cooperation between parasite and intestinal microbiota in small intestine inflammation development and endogenous IL-22 seems to exert a protective role independently of its effect on the microbiota. In conclusion, IL-22 participates in T.gondii induced acute small intestinal inflammation independently of microbiota and Reg3γ.

Histo-cytochemistry and scanning electron microscopy for studying spatial and temporal extraction of metabolites induced by ultrasound. Towards chain detexturation mechanism.

There are more than 1300 articles in scientific literature dealing with positive impacts of Ultrasound-Assisted Extraction (UAE) such as reduction of extraction time, diminution of solvent and energy used, enhancement in yield and even selectivity, intensification of diffusion, and eliminating wastes. This present study aims to understand what are the mechanism(s) behind these positive impacts which will help to design a decision tool for UAE of natural products. Different microscopic observations (Scanning Electron Microscopy (SEM), Environmental Scanning Electron Microscopy (e-SEM), Cyto-histochemistry) have been used for spacial and temporal localization of metabolites in rosemary leaves, which is one of the most studied and most important plant for its antioxidant metabolites used in food industry, during conventional and ultrasound extraction. The study permits to highlight that ultrasound impacted rosemary leaves not by a single or different mechanisms in function of ultrasound power, as described by previous studies, but by a chain detexturation mechanism in a special order: local erosion, shear forces, sonoporation, fragmentation, capillary effect, and detexturation. These detexturation impacts followed a special order during ultrasound treatment leading at the end to the total detexturation of rosemary leaves. These mechanisms and detexturation impacts were identified in glandular trichomes, non-glandular-trichomes and the layer adaxial and abaxial cuticle. Modelling metabolites diffusion phenomenon during conventional and ultrasound extraction with the second Fick's law allowed the estimation of diffusivities and solvent penetration into the inner tissues and in meantime to accelerate the release of valuable metabolites.

Dopamine D3 receptors are involved in amphetamine-induced contralateral rotation in 6-OHDA lesioned rats.

The aim of the present experiment was to investigate the possibility that alterations in dopamine D3 receptors have a role in the normalization of function that occurs following a unilateral lesion of the medial forebrain bundle induced by 6-hydroxydopamine (6-OHDA). Unilateral lesions result in an enhanced rotational response to dopamine agonists that appears to be due to an increase in stimulatory D2 receptors on the lesioned side that occurs by about 1 week postlesion. The present experiment assessed the involvement of D3 receptors in rotational behavior by testing the animals at 48 h postlesion. At this time interval, D2 receptors have not become up-regulated. In contrast, D3 receptors have been shown to be down-regulated. Rats with > or = 98% dopamine depletion induced by 6-OHDA exhibited mostly ipsilateral rotation in response to an injection of amphetamine. This rotation was not affected by pretreatment with the D3 antagonist U-99194A. Rats with 80-97% dopamine depletion exhibited mostly contralateral rotation in response to amphetamine and this rotation was blocked by pretreatment with U-99194A. In addition, a decrease in D3 receptor binding was observed by 48 h postlesion. These results support the hypothesis that the decrease in D3 receptors seen following denervation is involved in the compensatory response of the system. This may have important clinical relevance in the treatment of disorders such as Parkinson's disease and drug abuse.

Effect of 6-hydroxydopamine or repeated amphetamine treatment on mesencephalic mRNA levels for AMPA glutamate receptor subunits in the rat.

Expression of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) subunit mRNAs were assayed in the ventral mesencephalon of rats that received either a unilateral microinjection of the dopamine neurotoxin 6-hydroxydopamine (6-OHDA; Experiment 1) or repeated treatment with amphetamine (Experiment 2). GluR2 levels were decreased 1 and 3 days after the lesion, and GluR1 and GluR3 levels also showed a transient decrease at 1 day after the lesion. Repeated amphetamine treatment did not significantly alter GluR1-4 levels measured 30 min after the third or tenth amphetamine injection, even though locomotor sensitization was obtained. Thus, while the present results indicate that AMPA receptor subunits are associated with dopamine-containing cell bodies in the ventral mesencephalon, these transcripts may not be responsible for the development of amphetamine sensitization.

Individual differences in novelty-induced activity and the rewarding effects of novelty and amphetamine in rats.

Previous work has shown that individual differences in locomotor behavior in an inescapable novel environment predict the locomotor-stimulant effect of amphetamine. Experiment 1 of the present study assessed if novelty-seeking behavior in a free choice situation also predicts the locomotor-stimulant effect of amphetamine. Rats were first assessed for their locomotor response to an inescapable novel environment and then were allowed to choose between this environment (familiar) and a novel environment. Activity in the inescapable novel environment was found to predict subsequent locomotor response to amphetamine, but approach to novelty in the free choice situation did not. In experiment 2, rats were assessed for their approach to novelty in the free choice situation and then assessed for amphetamine-induced conditioned place preference. It was found that rats who spent more time in a novel environment also showed a higher magnitude of amphetamine-induced conditioned place preference. These findings are consistent with the hypothesis that the rewarding properties of novelty and amphetamine may be mediated by a similar brain mechanism.

Effect of differential rearing environments on morphine-induced behaviors, opioid receptors and dopamine synthesis.

Rats were raised from weaning (21 days old) to young adulthood (50-60 days old) in either an enriched or impoverished stimulus environment. In the enriched condition (EC), rats were group-housed with various novel objects that were re-arranged daily. In the impoverished condition (IC), rats were housed individually without any objects. As adults, a four-trial conditioned place preference (CPP) test was used to assess locomotor activity and reward produced by morphine (0, 0.1, 1 or 10 mg/kg). On morphine conditioning day 1, both EC and IC rats displayed an inverted U-shaped dose-effect curve for locomotor activity and the locomotor stimulant effect of acute morphine was greater in IC than EC rats. Across morphine conditioning days 1-4, both EC and IC rats displayed locomotor sensitization; the locomotor sensitization following repeated morphine injections was greater in IC than EC rats. In contrast to the enhanced locomotor stimulant effect of morphine observed in IC rats, morphine-induced CPP was attenuated in IC rats relative to EC rats, indicating that the locomotor and rewarding effects of opioids depend upon different neural substrates. Measurement of mu opioid receptor density and rates of morphine-stimulated dopamine synthesis in the mesolimbic and nigrostriatal systems of EC and IC rats revealed no reliable differences between groups. Therefore, the ability of mu opioid receptors to modulate mesolimbic dopamine neurotransmission does not account for the differential behavioral effects of morphine in EC and IC rats.

Repeated 7-OH-DPAT treatments: behavioral sensitization, dopamine synthesis and subsequent sensitivity to apomorphine and cocaine.

Male Wistar rats (250-350 g) were injected (SC) daily with the putative selective dopamine D3 receptor agonist, 7-OH-DPAT (0.01, 0.10, or 1.0 g/kg) or vehicle for 10 days. Fifteen minutes after each injection, the rats were tested for locomotor activity in photocell arenas for 20 min or 2 h. In two experiments, following this subchronic treatment, all rats received a challenge injection of apomorphine (1.0 mg/kg, SC), or cocaine (10 mg/kg, IP) on day 11, and were tested for locomotor activity. In a third experiment, dopamine synthesis in striatal and mesolimbic (nucleus accumbens-olfactory turbercle) tissue was assessed following acute or chronic 7-OH-DPAT treatments by measuring the accumulation of dihydroxyphenylalanine (DOPA) after treatment with a DOPA decarboxylase inhibitor. Major findings were as follows: a) acute 7-OH-DPAT treatment produced a dose-dependent decrease in locomotor activity; b) when tested for 2 h, the 1.0 mg/kg dose of 7-OH-DPAT produced a progressively greater increase in activity across the 10 test days (i.e., behavioral sensitization); c) subchronic treatment with 7-OH-DPAT did not result in cross-sensitization to either apomorphine or cocaine; d) acute treatment with the 1.0 mg/kg dose of 7-OH-DPAT significantly decreased dopamine synthesis in both striatal and mesolimbic regions; and e) chronic 7-OH-DPAT treatments did not affect basal dopamine synthesis in either brain region. Although the behavioral effects of 7-OH-DPAT were similar to the reported effects of the D2/D3 dopamine agonist quinpirole, the effects of repeated 7-OH-DPAT treatments differed from those of quinpirole in terms of cross-sensitization and basal dopamine synthesis. These results suggest that locomotor inhibition produced by low doses of 7-OH-DPAT is not related to dopamine autoreceptor stimulation, and the development of behavioral sensitization to high doses of 7-OH-DPAT is not due to the development of dopamine autoreceptor subsensitivity.

Biomarker assessments in asbestos-exposed workers as indicators for selective prevention of mesothelioma or bronchogenic carcinoma: rationale and practical implementations.

In the first part of this study we have shown how the serum levels of four selected tumour markers, namely tissue polypeptide antigen (TPA), carcino-embryonic antigen (CEA), hyaluronic acid (HA) and ferritin, display patterns characteristic of mesothelioma (M) or bronchogenic carcinoma (BC) in asbestos-exposed workers, and we hypothesize that the differences in marker patterns correspond to differences in carcinogenesis mechanisms. In a preliminary study, we found these specific marker patterns in 5/19 exposed workers of whom only one demonstrated any radiological signs of disease. Thus these specific marker patterns may be early events, occurring long (possibly years) before the classical radiological signs of exposure to asbestos. Accordingly they afford an optimal opportunity for prevention which should be adapted to the carcinogenesis mechanism as it is revealed by the marker pattern; it is aimed at antagonizing free radical carcinogenesis in all persons with TPA levels in excess of 100 U/l or Ferritin in excess of 400 ng/ml, and at inhibiting chemical carcinogenesis in those having elevated CEA levels (over 3 ng/ml). The mechanisms involved in these inhibitory processes are described and discussed, as well as the practical implementations that proceed from them. A prevention trial is now being started among 300 active and retired workers of an asbestos-cement works in northern France; the design of the study is presented. This prevention programme should be maintained over many years and holds a strong potential for reducing the untoward effects of exposure to asbestos.

Biomarker assessments in asbestos-exposed workers as indicators for selective prevention of mesothelioma or bronchogenic carcinoma: rationale and practical implementations.

Asbestos-associated malignancies are one of the major industrial hazards of recent decades and will continue to be so until beyond the end of the century. It has been estimated that, in the United States alone, there will be 131,200 cancer deaths as a result of asbestos exposure. At present the early lesions are detected radiologically, by which time intervention is no longer effective. The aim of this study was to test the value of a battery of serum biomarkers in the early detection of malignancy and in distinguishing between the early stages of mesothelioma and bronchogenic carcinoma. Many of the biomarkers had no discriminating value but on the basis of four such markers (namely TPA, CEA, HA and ferritin) it has been possible to distinguish between the late stages of the two malignancies and asbestosis. The results are discussed in terms of their possible application to the detection of early pre-malignant lesions in a screened population of asbestos-exposed persons, with the aim of attempting to prevent cancer death in such early detected cases.

[Effects of isosorbide dinitrate injection on acute myocardial infarction. A haemodynamic and gamma-angiographic study (author's transl)]. / Effets de l'isosorbide dinitrate injectable au stade aigu de l'infarctus du myocarde. Etude hémodynamique et gamma-angiographique.

The haemodynamic and gamma-angiographic effects of isosorbide dinitrate (ISDN) injection were evaluated in 18 patients with recent myocardial infarction by measuring diastolic (DPAP) and systolic (SPAP) pulmonary artery pressures, diastolic (DAP) and systolic (SAP) systemic arterial pressures, cardiac index (CI) and heart rate (HR). Total ejection fraction (EF) was measured by radionuclide angiography. Within the first hour of treatment, there was a significant fall in DPAP (from 25.11 +/- 6.5 to 18.3 +/- 6 mmHg), SPAP (from 47 +/- 11.5 to 36.6 +/- 10 mmHg) and SAP (from 140 +/- 27.8 to 123 +/- 20 mmHg). Changes in DAP, CI and HR were not significant. The drug produced a significant increase in EF (from 32.6 +/- 15 to 35.3 +/- 15 p. cent). On the basis of these results the patients could be divided into three categories: -- Group I patients (n = 5) with EF greater than 45, in whom the haemodynamic effects (fall in DRAP from 20.8 +/- 4.2 to 16.3 +/- 3 mmHg) and the gamma-angiographic effects (increase in EF from 53.8 +/- 6 to 58.6 +/- 3 p. cent) were favourable. -- Group II patients (n = 5) with EF less than 40, in whom the haemodynamic effects (fall in DRAP from 29 +/- 8.5 to 17.8 +/- 6 mmHg) and the gamma-angiographic effects (increase in EF from 23 +/- 9 to 34 +/- 7 p. cent) were still favourable. -- Group III patients (n = 8) with low EF, in whom there were no significant changes in haemodynamic effects (DPAP from 25.3 +/- 3 to 23.4 +/- 5 mmHg) and gamma-angiographic effects (EF from 26 +/- 6 to 25 +/- 5 p. cent). This group corresponds to cases with very extensive necrosis of unfavourable outcome (4 deaths). One may therefore consider that the lack of effectiveness of ISDN in subjects with left ventricular failure and low EF is of poor prognosis and requires more aggressive therapy.