Nasopharyngeal Viral and Bacterial Co-Detection among Children from Low- and Middle-Income Countries with and without Pneumonia

The role of microbial coinfection in the pathogenesis of pneumonia in children is not well known. The aim of this work was to describe the prevalence of microorganism co-detection in nasopharyngeal samples (NPS) of pneumonia cases and control subjects and to study the potential association between nasopharyngeal microorganism co-detection and pneumonia. A case-control study was carried out from 2010 to 2014 in nine study sites located in low- or middle-income countries. The data from 888 children under 5 years of age with pneumonia (cases) and 870 children under 5 without pneumonia (controls) were analyzed. Nasopharyngeal samples were collected; reverse transcription polymerase chain reaction (RT-PCR) enabled the detection of five bacteria and 19 viruses. Multiple, mixed-effects logistic regression modeling was undertaken to evaluate the association between microorganism co-detection and pneumonia. A single Streptococcus pneumoniae colonization was observed in 15.2% of the controls and 10.1% of the cases (P = 0.001), whereas S. pneumoniae and a single virus co-detection was observed in 33.3% of the cases and in 14.6% of the controls (P < 0.001). Co-detections with rhinovirus, respiratory syncytial virus, parainfluenza virus, human metapneumovirus, and influenza virus were more frequent in the cases compared with the controls (P < 0.001) and were significantly associated with pneumonia in multiple regression analysis. The proportion of single virus detection without bacterial co-detection was not different between cases and controls (13.6% versus 11.3%, P = 0.13). This study suggests that coinfection of S. pneumoniae and certain viruses may play a role in the pathophysiology of pneumonia in children.

POS0259 ULTRASOUND AS AN IMAGING BIOMARKER OF EARLY RESPONSE TO TOCILIZUMAB AND METHOTREXATE IN VERY EARLY RHEUMATOID ARTHRITIS, TOVERA – A LONGITUDINAL STUDY

Background:

The combination of methotrexate (MTX) and tocilizumab (TCZ) has been proven to be superior to MTX alone in early rheumatoid arthritis (RA)1 and was able to prevent radiographic progression. Ultrasound (US) has become a valid imaging modality in managing RA. Together with clinical examination, US may allow a comprehensive monitoring of response to therapy. So far, few data are available concerning the early response to TCZ plus MTX in very early RA (VERA).

Objectives:

In this study we aimed to assess the early US response to TCZ plus MTX in VERA, DMARD-naïve patients.

Methods:

In this open-label, single-arm study, VERA patients received TCZ (162 mg/week, subcutaneously) and MTX (15-20 mg/week, per os) for 24 weeks as induction therapy, followed by MTX as maintenance therapy. RA was diagnosed according to the 2010 ACR/European league against rheumatism (EULAR) criteria. All patients who fulfilled the inclusion criteria (ClinicalTrials.gov: NCT02837146) underwent blood tests, clinical and ultrasound examinations at the predefined time-points: 0,2,4,8,12,24,32,48,54 weeks (w). Ultrasound examination of 34 joints (elbows, wrists, MCP [1-5, bilateral], PIP ([2-5, bilateral], knees, ankles and MTP [2-5, bilateral]) was performed blindly to clinical data. Gray-scale (GS), power-Doppler (PD) scores, and the global OMERACT-EULAR synovitis score (GLOESS) were assessed in each joint. The sum of individual scores was calculated for 17-joint score (JS) (whole joint set), 10-JS (wrists, MCP, ankles and MTP joints), 12-JS2, and 7-JS3.

Results:

Forty-four patients (77% women), aged 46.7 ± 12.4 years, completed the 24-week period. Two-thirds (72.7%) were positive for anti-citrullinated protein antibody (ACPA) and 18.2% had bone erosions. At baseline, the mean 28 swollen joints count (28-SJC) was 7.55± 4.5, mean disease activity score (DAS28)-CRP score was 5.2 ± 0.15, mean simplified clinical activity score (SDAI) was 31.4 ± 1.9, mean clinical activity score (CDAI) was 29.1 ± 1.8 and mean health assessments questionnaire (HAQ) score was 1.3 ± 0.1. The C-reactive protein (CRP) decreased significantly at 2w (p<0.05) and, accordingly DAS28-CRP score decreased significantly at 4w (p<0.05). The 28-SJC and CDAI scores decreased significantly at 8w (p<0.05). The HAQ and visual analogue scale (VAS) disease activity reported by patients decreased significantly at 8w (p<0.05) and VAS fatigue at 12w (p<0.05).

The GLOESS and GS scores allowed us detecting the earliest significant treatment response at 2w and PD scores at 4w (p<0.05). Among US joint subsets, 17-JS (p<0.01), 12-JS (p<0.05) and 10-JS (p<0.05) were able to detect the earliest treatment response at 2w. The 7-joint score detected the earliest response at 4w, both in GS and PD (p<0.05).

Conclusion:

US scores were able to detect therapeutic response to TCZ plus MTX earlier than clinical scores and may therefore be a promising imaging biomarker.

References:

[1]Burmester GR et al. Ann Rheum Dis 2017; 76; 1279-1284.

[2]Naredo E et al. Arthritis Rheum 2008; 59(4): 515-522.

[3]Backhaus M et al. Arthritis Rheum 2009; 61: 1194-1201.

Disclosure of Interests:

Maria Stoenoiu Grant/research support from: UCB, Roche, Abbvie, MSD, Sanofi, Celgene, Mihaela Maruseac: None declared, Mouna Messaoudi: None declared, Adrien Nzeusseu Toukap Grant/research support from: AbbVie, Eli Lilly, Janssen, UCB, Novartis, Celgene Corporation, Pfizer, Esperanza Naredo Grant/research support from: AbbVie, Roche, BMS, Pfizer, UCB, Eli Lilly, Novartis, Janssen, Celgene

Serotypes of Streptococcus pneumoniae in Children Aged <5 Years Hospitalized With or Without Pneumonia in Developing and Emerging Countries: A Descriptive, Multicenter Study

BACKGROUND

Improving knowledge regarding Streptococcus pneumoniae distribution in pneumonia cases is important to better target preventive and curative measures. The objective was to describe S. pneumoniae serotypes in children with or without pneumonia.

METHODS

It was a case-control study carried out in 8 developing and emerging countries between 2010 and 2014. Cases were children aged <5 years admitted to the hospital for pneumonia. Controls were children admitted for surgery or routine outpatient care.

RESULTS

In nasopharyngeal samples, S. pneumoniae were detected in 68.2% of the cases and 47.5% of the controls (P < .001). Nasopharyngeal carriage was associated with a higher risk of being a case in 6/8 study sites (adjusted odds ratio ranged from 0.71 [95% confidence interval [CI], .39-1.29; P = .26] in India [Pune/Vadu] to 11.86 [95% CI, 5.77-24.41; P < .001] in Mongolia). The 13-valent pneumococcal conjugate vaccine (PCV13) serotypes were more frequently detected in cases with nasopharyngeal carriage (67.1%) than in controls with nasopharyngeal carriage (54.6%), P < .001. Streptococcus pneumoniae was detected in blood by polymerase chain reaction in 8.3% of the cases. Of 34 cases with an S. pneumoniae serotype detected in blood, 27 (79%) had the same serotype in the nasopharyngeal sample.

CONCLUSIONS

The results confirm the assumption that the isolate carrying or causing disease in an individual is of the same serotype. Most serotypes independently associated with nasopharyngeal carriage or pneumonia are covered by PCV13, suggesting that increased PCV coverage would reduce the burden of S. pneumoniae-related pneumonia.

Patchy landscapes in arid environments: Nonlinear analysis of the interaction-redistribution model

We consider a generic interaction-redistribution model of vegetation dynamics to investigate the formation of patchy vegetation in semi-arid and arid landscapes. First, we perform a weakly nonlinear analysis in the neighborhood of the symmetry-breaking instability. Following this analysis, we construct the bifurcation diagram of the biomass density. The weakly nonlinear analysis allows us to establish the condition under which the transition from super- to subcritical symmetry-breaking instability takes place. Second, we generate a random distribution of localized patches of vegetation numerically. This behavior occurs in regimes where a bare state coexists with a uniform biomass density. Field observations allow to estimate the total biomass density and the range of facilitative and competitive interactions.

Observation and modelling of vegetation spirals and arcs in isotropic environmental conditions: dissipative structures in arid landscapes

We report for the first time on the formation of spirals like vegetation patterns in isotropic and uniform environmental conditions. The vegetation spirals are not waves and they do not rotate. They belong to the class of dissipative structures found out of equilibrium. Isolated or interacting spirals and arcs observed in South America (Bolivia) and North Africa (Morocco) are interpreted as a result of curvature instability that affects the circular shape of localized patches. The biomass exhibits a dynamical behaviour with arcs that transform into spirals. Interpretation of observations and of the predictions provided by the theory is illustrated by recent measurements of peculiar plant morphology (the alfa plant, or Stipa tenacissima L.) originated from northwestern Africa and the southern part of the Iberian Peninsula.This article is part of the theme issue 'Dissipative structures in matter out of equilibrium: from chemistry, photonics and biology (part 2)'.

Microorganisms Associated With Pneumonia in Children <5 Years of Age in Developing and Emerging Countries: The GABRIEL Pneumonia Multicenter, Prospective, Case-Control Study

Background

Pneumonia, the leading infectious cause of child mortality globally, mainly afflicts developing countries. This prospective observational study aimed to assess the microorganisms associated with pneumonia in children aged <5 years in developing and emerging countries.

Methods

A multicenter, case-control study by the GABRIEL (Global Approach to Biological Research, Infectious diseases and Epidemics in Low-income countries) network was conducted between 2010 and 2014 in Cambodia, China, Haiti, India (2 sites), Madagascar, Mali, Mongolia, and Paraguay. Cases were hospitalized children with radiologically confirmed pneumonia; controls were children from the same setting without any features suggestive of pneumonia. Nasopharyngeal swabs were collected from all subjects; 19 viruses and 5 bacteria were identified by reverse-transcription polymerase chain reaction. Associations between microorganisms and pneumonia were quantified by calculating the adjusted population attributable fraction (aPAF) after multivariate logistic regression analysis adjusted for sex, age, time period, other pathogens, and site.

Results

Overall, 888 cases and 870 controls were analyzed; ≥1 microorganism was detected in respiratory samples in 93.0% of cases and 74.4% of controls (P < .001). Streptococcus pneumoniae, Mycoplasma pneumoniae, human metapneumovirus, rhinovirus, respiratory syncytial virus (RSV), parainfluenza virus 1, 3, and 4, and influenza virus A and B were independently associated with pneumonia; aPAF was 42.2% (95% confidence interval [CI], 35.5%-48.2%) for S. pneumoniae, 18.2% (95% CI, 17.4%-19.0%) for RSV, and 11.2% (95% CI, 7.5%-14.7%) for rhinovirus.

Conclusions

Streptococcus pneumoniae, RSV, and rhinovirus may be the major microorganisms associated with pneumonia infections in children <5 years of age from developing and emerging countries. Increasing S. pneumoniae vaccination coverage may substantially reduce the burden of pneumonia among children in developing countries.

Burden of Influenza in Less Than 5-Year-Old Children Admitted to Hospital with Pneumonia in Developing and Emerging Countries: A Descriptive, Multicenter Study

This descriptive 4-year study reports the proportion of detection of influenza viruses in less than 5-year-old children hospitalized for pneumonia in eight developing and emerging countries and describes clinical and microbiological characteristics of influenza-related pneumonia cases. Hospitalized children presenting radiologically confirmed pneumonia aged 2-60 months were prospectively enrolled in this observational standardized study. Mean proportion of isolated influenza virus was 9.7% (95% confidence interval: 7.9-11.8%) among 888 pneumonia children analyzed, with moderate heterogeneity between countries-ranging from 6.2% in Cambodia to 18.8% in Haiti. The clinical characteristics of children with influenza-related pneumonia were not substantially different from those of other pneumonia cases. Influenza A H1N1-related pneumonia cases appeared as more severe than pneumonia cases related to other strains of influenza. Streptococcus pneumoniae was detected more often in blood samples from influenza-related cases than in those without detected influenza viruses (19.7% versus 9.5%, P = 0.018). Influenza-related pneumonia is frequent among children less than 5 years old with pneumonia, living in developing and emerging countries. Influenza might be a frequent etiologic agent responsible for pneumonia or a predisposing status factor for pneumococcal-related pneumonia in this population.

Serotype Distribution of Clinical Streptococcus pneumoniae Isolates before the Introduction of the 13-Valent Pneumococcal Conjugate Vaccine in Cambodia

Childhood vaccination with the 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in Cambodia in January 2015. Baseline data regarding circulating serotypes are scarce. All microbiology laboratories in Cambodia were contacted for identification of stored isolates of Streptococcus pneumoniae from clinical specimens taken before the introduction of PCV13. Available isolates were serotyped using a multiplex polymerase chain reaction method. Among 166 identified isolates available for serotyping from patients with pneumococcal disease, 4% were isolated from upper respiratory samples and 80% were from lower respiratory samples, and 16% were invasive isolates. PCV13 serotypes accounted for 60% (95% confidence interval [CI] 52–67) of all isolates; 56% (95% CI 48–64) of noninvasive and 77% (95% CI 57–89) of invasive isolates. Antibiotic resistance was more common among PCV13 serotypes. This study of clinical S. pneumoniae isolates supports the potential for high reduction in pneumococcal disease burden and may serve as baseline data for future monitoring of S. pneumoniae serotypes circulation after implementation of PCV13 childhood vaccination in Cambodia.

Viral and bacterial co-infection in severe pneumonia triggers innate immune responses and specifically enhances IP-10: a translational study

Mixed viral and bacterial infections are widely described in community-acquired pneumonia; however, the clinical implications of co-infection on the associated immunopathology remain poorly studied. In this study, microRNA, mRNA and cytokine/chemokine secretion profiling were investigated for human monocyte-derived macrophages infected in-vitro with Influenza virus A/H1N1 and/or Streptococcus pneumoniae. We observed that the in-vitro co-infection synergistically increased interferon-γ-induced protein-10 (CXCL10, IP-10) expression compared to the singly-infected cells conditions. We demonstrated that endogenous miRNA-200a-3p, whose expression was synergistically induced following co-infection, indirectly regulates CXCL10 expression by targeting suppressor of cytokine signaling-6 (SOCS-6), a well-known regulator of the JAK-STAT signaling pathway. Additionally, in a subsequent clinical pilot study, immunomodulators levels were evaluated in samples from 74 children (≤5 years-old) hospitalized with viral and/or bacterial community-acquired pneumonia. Clinically, among the 74 cases of pneumonia, patients with identified mixed-detection had significantly higher (3.6-fold) serum IP-10 levels than those with a single detection (P = 0.03), and were significantly associated with severe pneumonia (P < 0.01). This study demonstrates that viral and bacterial co-infection modulates the JAK-STAT signaling pathway and leads to exacerbated IP-10 expression, which could play a major role in the pathogenesis of pneumonia.

Behavioral and neurochemical effects of dietary methyl donor deficiency combined with unpredictable chronic mild stress in rats

Methyl donor deficiencies and chronic stress cause depression independently, but their interaction has never been thoroughly evaluated. In our study, methyl donor deficient diet and chronic stress condition consisted respectively of a B2, B9, B12, and choline-free diet and a chronic mild stress procedure. Rats were randomly assigned to six groups with three "diet" conditions (free-feeding, pair-fed and methyl donor deficient diet) and two "stress" conditions (no-stress and stress) and were evaluated in the open-field, the elevated plus-maze and the forced swimming test. After the behavioral evaluation, corticosterone and homocysteine plasma levels were measured and dopamine, DOPAC, serotonin, 5HIAA concentrations were evaluated in several brain areas. Rats given a methyl donor deficient diet for 11 weeks causing elevated plasma homocysteine levels were compared to pair-fed and free-feeding rats with or without unpredictable chronic mild stress. Regardless of stress environmental conditions, the methyl donor deficient diet decreased plasma corticosterone levels and caused disinhibition in the elevated plus-maze condition relative to both control groups. However, stress potentiated the effects of the deficient regimen on rearing in the open-field and climbing in the forced swim test. The dietary changes involved in behavior and plasma corticosterone could be caused by homocysteine-induced decreases in dopamine and 5-hydroxytryptamine metabolites in selective brain regions and it can be noted that regardless of stress-conditions, methyl donor deficient diet decreases DOPAC/dopamine and 5HIAA/serotonin ratios in striatum and hypothalamus and selectively 5HIAA/serotonin ratio in the sensorimotor cortex. Our experimental data is particularly relevant in the context of neuropsychiatric disorders frequently associated with folate deficiency and hyperhomocysteinemia.

Systemically active human opiorphin is a potent yet non-addictive analgesic without drug tolerance effects

Human opiorphin QRFSR-peptide protects enkephalins from degradation by human neutral endopeptidase (hNEP) and aminopeptidase-N (hAP-N) and inhibits pain perception in a behavioral model of mechanical acute pain (1). Here, using two other pain rat models, the tail-flick and the formalin tests, we assess the potency and duration of the antinociceptive action of opiorphin with reference to morphine. The occurrence of adverse effects with emphasis on the side-effect profile at equi-analgesic doses was compared. We demonstrate that opiorphin elicits minimal adverse morphine-associated effects, at doses (1-2 mg/kg, i.v.) that produce a comparable analgesic potency in both spinally controlled thermal-induced acute and peripheral chemical-induced tonic nociception. The analgesic response induced by opiorphin in the formalin-induced pain model preferentially requires activation of endogenous mu-opioid pathways. However, in contrast to exogenous mu-opioid agonists such as morphine, opiorphin, does not develop significant abuse liability or antinociceptive drug tolerance after subchronic treatment. In addition, anti-peristaltism was not observed. We conclude that opiorphin, by inhibiting the destruction of endogenous enkephalins, which are released according to the painful stimulus, activates restricted opioid pathways specifically involved in pain control, thus contributing to a greater balance between analgesia and side-effects than found with morphine. Therefore, opiorphin could give rise to new analgesics endowed with potencies similar to morphine but with fewer adverse effects than opioid agonists. Its chemical optimization, to generate functional derivatives endowed with better bioavailability properties than the native peptide, could lead to a potent class of physiological type analgesics.

Human opiorphin is a naturally occurring antidepressant acting selectively on enkephalin-dependent delta-opioid pathways

Human opiorphin protects enkephalins from degradation by human neutral endopeptidase and aminopeptidase-N and inhibits pain perception in various behavioral rodent models of pain via endogenous enkephalin-related activation of opioidergic pathways. In addition to pain control, endogenous opioid pathways are also implicated in the modulation of emotion-related behaviors. Thus, we explored the dose-dependent motivational responses induced by opiorphin using the forced swim test, the standard rat model of depression. In addition, to further understand the endogenous events triggered by opiorphin, we investigated the specific involvement of mu- or delta-opioid receptor-dependent pathways. In parallel, the locomotor activity test was used to detect possible sedation or hyperactivity. Here, we report for the first time that at 1-2 mg/kg i.v. doses, opiorphin elicited antidepressant-like effects by activating endogenous delta-opioidergic pathways, since that activation was reversed by the selective delta-opioid antagonist naldrindole (10 mg/kg i.p.). The antidepressive behavioral responses exerted by opiorphin are specific at systemically active doses. Treated-rats did not develop either hypo- or hyper-active responses in a locomotor test or amnesic behavioral response in the passive avoidance rat model. In addition, opiorphin did not induce either anxiolytic-, or anxiogenic-like responses in the conditioned defensive burying test. Taking the data together, we conclude that opiorphin is able to elicit antidepressant-like effects, mediated via delta-opioid receptor-dependent pathways, by modulating the concentrations of endogenous enkephalin released in response to specific physical and/or psychological stimuli. Thus, opiorphin or optimized derivatives is a promising single candidate to treat disorders that include both pain and mood disorders, particularly depression.

[Acute psychotic disorders related to bupropion: review of the literature]

RATIONALE AND OBJECTIVES

Bupropion, or amfebutamone, is an atypical antidepressant also used during tobacco cessation. From a structural standpoint, it resembles amphetamine drugs with psychostimulant effects, and endogenous monoamines. From a pharmacological standpoint, bupropion, and two of its most important active metabolites, inhibit dopamine and norepinephrine reuptake. It has recently been discovered that bupropion may act as a non-competitive cholinergic nicotinic receptor antagonist, and that it may inhibit the activation of reward systems triggered by nicotine. Buproprion's efficacy as a smoking cessation aid has been demonstrated by numerous clinical trials that have compared its effects with those of placebo and other nicotinic substitutes. In 2001, buproprion SR received marketing authorization in France as a smoking cessation aid, under the name ZYBAN®. Tobacco addiction indeed remains a major public health issue. Among patients with psychiatric conditions, chronic tobacco consumption is frequent. The development of non-nicotinic drugs may therefore enhance therapeutic possibilities. However, the psychotropic effects of these molecules should be taken into account. We have recently reported the case of a patient with schizoaffective disorder, who presented two acute bupropion-induced psychotic episodes. We have also undertaken an exhaustive bibliographical research on this subject. The aim of the present study is to present the information available to us, in order to suggest aetiopathogenic hypotheses and therapeutic proposals.

DATA SOURCES

The following databases were consulted on a regular basis, with no date restriction: Medline, Cochrane and Elsevier. The present study identified 22 cases of psychotic conditions associated with buproprion, as well as randomized and pharmacovigilance studies published in English, from December 1985 to November 2008. Since 2002, there have been three published case-reports on patients who underwent a tobacco cessation program.

DATA SYNTHESIS

Psychotic disorders associated with buproprion appear after an average of 10 days of 300 mg/d bupropion intake. In about two third of cases, the patients have no history of psychiatric conditions. In one third of cases, they have a history of thymic disorders. In our review, auditory, visual or cenaesthetic hallucinations frequently occur (85% of the reported cases), and are sometimes characterized by single episodes and/or are rationalized. Some of them occur along with delusional episodes (mystical, paranoid, etc.). The patients are restless, confused, but seldom exhibit dissociative and thymic symptoms.

DISCUSSION AND CONCLUSIONS

From an aetiopathogenic, clinical and evolutive standpoint, buproprion-induced psychotic episodes share many similarities with acute organic or toxic psychosis (notably induced by amphetamines). The hypothesis of a dopaminergic hyper-reactivity should be analyzed. Moreover, most of these patients were taking other medication, and the possibility of a dopaminergic potentialization prior to buproprion intake could be suggested. In such cases, bupropion should be discontinued and complete remission is expected within an average of 10 days. Even though neuroleptic drugs are still frequently used in these cases, benzodiazepines could become a valid alternative, according to the model of amphetamine-induced acute psychosis.

Effect of music therapy on anxiety and depression in patients with Alzheimer's type dementia: randomised, controlled study

BACKGROUND/AIMS

Numerous studies have indicated the value of music therapy in the management of patients with Alzheimer's disease. A recent pilot study demonstrated the feasibility and usefulness of a new music therapy technique. The aim of this controlled, randomised study was to assess the effects of this new music therapy technique on anxiety and depression in patients with mild to moderate Alzheimer-type dementia.

METHODS

This was a single-centre, comparative, controlled, randomised study, with blinded assessment of its results. The duration of follow-up was 24 weeks. The treated group (n = 15) participated in weekly sessions of individual, receptive music therapy. The musical style of the session was chosen by the patient. The validated 'U' technique was employed. The control group (n = 15) participated under the same conditions in reading sessions. The principal endpoint, measured at weeks 1, 4, 8, 16 and 24, was the level of anxiety (Hamilton Scale). Changes in the depression score (Geriatric Depression Scale) were also analyzed as a secondary endpoint.

RESULTS

Significant improvements in anxiety (p < 0.01) and depression (p < 0.01) were observed in the music therapy group as from week 4 and until week 16. The effect of music therapy was sustained for up to 8 weeks after the discontinuation of sessions between weeks 16 and 24 (p < 0.01).

CONCLUSION

These results confirm the valuable effect of music therapy on anxiety and depression in patients with mild to moderate Alzheimer's disease. This new music therapy technique is simple to implement and can easily be integrated in a multidisciplinary programme for the management of Alzheimer's disease.

Preventive antioxidant effects of cocoa polyphenolic extract on free radical production and cognitive performances after heat exposure in Wistar rats

The preventive effects of ACTICOA powder (AP), a cocoa polyphenolic extract, on free radicals produced by leucocytes in rats after heat exposure (HE) and its protective effects on subsequent cognitive impairments were assessed. AP or vitamin E, the antioxidant reference, was orally administered to rats for 14 d before HE at 40 degrees C temperature during 2 h. The day after HE, free radical production by leucocytes in rats treated with AP or vitamin E was significantly reduced as compared to control. Unlike controls, AP- and vitamin E-treated rats discriminated between active lever and inactive levers in a light extinction paradigm. In the Morris water maze, escape latencies before reaching the hidden platform by AP- and vitamin E-treated rats decreased throughout testing. The daily oral administration of AP or vitamin E protected rats from cognitive impairments after HE by counteracting the overproduction of free radicals.

Activation analysis and first occupational dose rates estimates for the Laser Megajoule facility

A three-dimensional neutronic modelling of the LMJ facility has been performed. The Monte Carlo transport code TRIPOLI is used to obtain the neutron spectra required for the inventory code FISPACT. Nodal activation responses and time-dependent decay gamma spectra are produced and used as source terms for further treatment by TRIPOLI for a range of engineering and safety assessments. It is shown that three-dimensional neutronic and nodal activation can be performed in a convenient way and the results obtained by this procedure will serve as a data-base for design and S&E analysis.

The endogenous androgen-regulated sialorphin modulates male rat sexual behavior

In sexually mature male rats, sialorphin is synthesized under androgenic control and its surge endocrine secretion is evoked in response to environmental acute stress. These findings led us to suggest that this signaling mediator might play a role in physiological and behavioral integration, especially reproduction. The present study investigates the effects induced by sialorphin on the male sexual behavior pattern. Intact male rats were treated in acute mode, with sialorphin at the 0.3, 1, and 3 microg/kg doses, before being paired with receptive female for 45 min. The data obtained show that sialorphin increased, in a dose-related manner, the occurrence of intromissions across the successive ejaculatory sequences. The rats treated with the highest 3 microg/kg dose significantly ejaculated less often compared to controls; however, 80% of them achieved up to three ejaculations. Further analyses of mount bouts for rats achieving three ejaculations reveal that there were significant stimulatory effects of sialorphin, at all doses, on the frequency of intromissions before ejaculation and on the propensity of males to engage in investigatory behavior directed to the female during the post-ejaculatory interval. Thus, sialorphin has the ability to modulate, at doses related to physiological circulating levels, the male rat mating pattern, that is, exerting a dual facilitative or inhibitory dose-dependent effect on the sexual performance, while stimulating the apparent sexual arousal or motivation. These findings led us to speculate that the endogenous androgen-regulated sialorphin helps modulate the adaptative balance between excitatory and inhibitory mechanisms serving appropriate male rat sexual response, depending on the context.

Behavioral evaluation of visceral pain in a rat model of colonic inflammation

A new rat model was established up to evaluate the antinociceptive effect of compounds in visceral pain. The test consisted in measuring the performance of rats in an aversive light stimulus avoidance experimental device. Rats with TNBS-induced colitis had a lower number of total active lever pressings and did not discriminate the active lever from the inactive one. Morphine (1 mg/kg, s.c.) and CI-977 (0.001 mg/kg, s.c.) treatment restored the level of pressing activity of animals and their ability to discriminate the active lever from the inactive one. Naloxone treatment antagonized the improvement of performance produced by morphine. The results obtained indicate that this behavioral paradigm may be used to evaluate the antinociceptive potential of compounds.

Effects of MPTP on lever-pressing for light extinction in rats

Rats were daily treated for seven days with 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine (MPTP) at a dose of 20 mg/kg/day, i.p. Seven days after treatment withdrawal, the rats were individually tested in a brightly lit apparatus containing two levers: an active lever allowing periods of darkness, and an inactive one. The test was performed over two consecutive days, in 20-min sessions. While control rats had a higher number of total active lever pressings than inactive lever pressings, this was not the case for MPTP-treated rats. Control rats decreased their useless active lever pressings and inactive lever pressings across the two sessions, but MPTP-treated rats did not do either. The absence of the differential effect in rats injected with MPTP may be due to a reduction in reinforcement mechanisms caused by the mild depletion of dopamine in the striatum.