Golgi staining-like retrograde labeling of brain circuits using rabies virus: Focus onto the striatonigral neurons.

BACKGROUND: The introduction of viral transneuronal tracers in the toolbox of neural tract-tracing methods has been an important addition in the field of connectomics for deciphering circuit-level architecture of the nervous system. One of the added values of viral compared to conventional retrograde tracers, in particular of rabies virus, is to provide a Golgi staining-like view of the infected neurons, revealing the thin dendritic arborizations and the spines that are major post-synaptic seats of neuronal connections. NEWMETHOD: Here, we comparatively illustrate the characteristics of the labeling obtained in the same model system, the basal ganglia circuitry, by different retrograde viral tracing approaches, using the Bartha strain of pseudorabies virus, the SAD and CVS strains of rabies virus and by the conventional retrograde tracer cholera toxin B. To best contrast the differences in the capacity of these tracers to reveal the dendritic morphology in details, we focused on one population of first-order infected neurons in the striatum, which exhibit high spine density, after tracer injection in the substantia nigra. RESULTS AND CONCLUSION: None of the viruses tested allowed to detect as many neurons as with cholera toxin B, but the SAD and CVS strains of rabies virus had the advantage of enabling detailed Golgi-like visualisation of the dendritic trees, the best numerical detection being offered by the transneuronal rCVS-N2c-P-mCherry while poor labeling was provided by rCVS-N2c-M-GFP. Results also suggest that, besides different viral properties, technical issues about constructs and detection methods contribute to apparently different efficiencies among the viral approaches.

[Ocular syphilis, a re-emergent pathology: Series of 12 patients in one Hospital, 2017]. / La syphilis oculaire, une pathologie ré-émergente : série de 12 patients au CHU de Marseille en 2017.

INTRODUCTION: Syphilis is a sexually transmitted disease. All organs might be affected, but ocular syphilis only occurs in 0.6 percent of patients. We collected all cases of ocular syphilis requiring hospitalization at the University Hospital Center (UHC) in Marseille in 2017. PATIENTS AND METHODS: This was a retrospective monocentric study. The diagnosis of ocular syphilis was based on the combination of ocular inflammation with a positive syphilitic serology. For each patient, sex, age, HIV status, ocular and extraocular symptoms, initial visual acuity, syphilis serology, cerebrospinal fluid (CSF) analysis if done, treatment and clinical response were collected. RESULTS: Ten men and two women, aged 28 to 86 years, were hospitalized. Two patients were HIV-positive. Ophtalmological lesions were heterogeneous the posterior structures were most affected. Anterior uveitis was isolated in one patient. Five patients had extraocular signs with cutaneous and/or mucosal involvement. No patient had neurological symptoms. Diagnosis of neurosyphilis through CSF analysis was definite for one patient, probable for 5 patients and ruled out for 2 patients. Six patients received treatment with penicillin G and six with ceftriaxone. Visual acuity improved in all cases. DISCUSSION: Ophtalmic cases of syphilis have become more frequent over the past few years in France. The diagnosis should be suspected in cases of eye inflammation even in the absence of favourable clinical presentation or anamnesis. Search for HIV co-infection should be systematic. Our study shows that ceftriaxone remains an effective alternative to penicillin G.

Pilot-Scale Pulsed UV Light Irradiation of Experimentally Infected Raspberries Suppresses Cryptosporidium parvum Infectivity in Immunocompetent Suckling Mice.

Cryptosporidium spp., a significant cause of foodborne infection, have been shown to be resistant to most chemical food disinfectant agents and infective for weeks in irrigation waters and stored fresh vegetal produce. Pulsed UV light (PL) has the potential to inactivate Cryptosporidium spp. on surfaces of raw or minimally processed foods or both. The present study aimed to evaluate the efficacy of PL on viability and in vivo infectivity of Cryptosporidium parvum oocysts present on raspberries, a known source of transmission to humans of oocyst-forming apicomplexan pathogens. The skin of each of 20 raspberries was experimentally inoculated with five 10-µl spots of an oocyst suspension containing 6 × 10(7) oocysts per ml (Nouzilly isolate). Raspberries were irradiated by PL flashes (4 J/cm(2) of total fluence). This dose did not affect colorimetric or organoleptic characteristics of fruits. After immunomagnetic separation from raspberries, oocysts were bleached and administered orally to neonatal suckling mice. Seven days after infection, mice were euthanized, and the number of oocysts in the entire small intestine was individually assessed by immunofluorescence flow cytometry. Three of 12 and 12 of 12 inoculated mice that received 10 and 100 oocysts isolated from nonirradiated raspberries, respectively, were found infected. Four of 12 and 2 of 12 inoculated mice that received 10(3) and 10(4) oocysts from irradiated raspberries, respectively, were found infected. Oocyst counts were lower in animals inoculated with 10(3) and 10(4) oocysts from irradiated raspberries (92 ± 144 and 38 ± 82, respectively) than in animals infected with 100 oocysts from nonirradiated raspberries (35,785 ± 66,221, P = 0.008). PL irradiation achieved oocyst reductions of 2 and 3 log for an inoculum of 10(3) and 10(4) oocysts, respectively. The present pilot-scale evaluation suggests that PL is an effective mode of decontamination for raspberries and prompts further applicability studies in industrial contexts.

Self-reported reading and writing skills in elderly who never attended school influence cognitive performances: results from the Coyoacán cohort study.

OBJECTIVES: Beyond the well-known effect of educational level on cognitive performances, the present study investigates the specific effect of literacy acquisition independently of education. DESIGN: A sample of 175 unschooled elderly participants was selected from a larger Mexican population-based cohort study. PARTICIPANTS: The sample of 175 subjects who never went to school was divided in two groups: 109 who never acquired literacy skills and 66 who declared having acquired reading and writing abilities. MEASUREMENTS: Cognitive performances on commonly used tests (mini mental state examination, Isaacs set test, free and cued selective reminding test and clock-drawing test) were compared between the two groups taking into account several potentially confounding factors. RESULTS: The participants with reading and writing skills performed better than their counterparts in most tests, even though no difference was observed for the Isaacs Set Test and the delayed recall of the free and cued selective reminding test. CONCLUSION: Writing and reading skills in elderly people with no formal education influence performances in very commonly used test. Not only educational level but also literacy acquisition should be taken into account when conducting cognitive assessment in very low educated elderly people.

Effects of octreotide on jejunal hypersensitivity triggered by Cryptosporidium parvum intestinal infection in an immunocompetent suckling rat model.

BACKGROUND: Similar to other bacterial or protozoan infections, human cryptosporidiosis may trigger postinfectious irritable bowel syndrome (IBS)-like symptoms, a condition in which enhanced visceral perception of pain during intestinal distension plays a pivotal role. In an immunocompetent suckling rat model which mimicks features of postinfectious IBS, Cryptosporidium parvum infection induces long-lasting jejunal hypersensitivity to distension in association with intestinal activated mast cell accumulation. The aim of the present study was to explore in this model whether octreotide, a somatostatin agonist analog, could prevent the development of jejunal hypersensitivity and intestinal mast cell/nerve fiber accumulation. METHODS: Five-day-old Sprague-Dawley rats were infected with C. parvum and treated 10 days later with octreotide (50 g kg(-1) day(-1), i.p.) for 7 days. KEY RESULTS: Compared with untreated infected rats, octreotide treatment of infected rats resulted in increased weight gain [day 23 postinfection (PI)], decreased food intake (day 16 PI), and a reduction in jejunal villus alterations (day 14 PI), CD3(+) IEL (day 37 PI) and mast cell (days 37 and 50 PI) accumulations, nerve fiber densities (day 50 PI), and hypersensitivity to distension (day 120 PI). In uninfected rats, the effects of octreotide treatment were limited to higher weight gain (days 16 and 23 PI) and decreased food intake (day 23 PI) compared with uninfected-untreated rats. CONCLUSIONS & INFERENCES: Data confirms the relevance of the present rat model to postinfectious IBS studies and prompt further investigation of somatostatin-dependent regulatory interactions in cryptosporidiosis.

Evaluation of water treatment plant UV reactor efficiency against Cryptosporidium parvum oocyst infectivity in immunocompetent suckling mice.

AIM: To assess the efficiency of a medium-pressure UV reactor under full-scale water treatment plant (WTP) conditions on the infectivity of Cryptosporidium parvum oocysts in an Naval Medical Research Institute (NMRI) suckling mice infectivity model. METHODS AND RESULTS: Six/seven-day-old mice were administered orally 2-10x10(4)Cryptosporidium parvum oocysts. Compared with nonirradiated oocysts, 40 mJ cm(-2) UV irradiation of ingested oocysts resulted 7 days later in a 3.4-4.0 log10 reduction in the counts of small intestine oocysts, using a fluorescent flow cytometry assay. CONCLUSION: Present data extend to industrial conditions previous observations of the efficiency of UV irradiation against Cryptosporidium parvum oocyst in vivo development. SIGNIFICANCE AND IMPACT OF THE STUDY: Present results suggest that in WTP conditions, a medium-pressure UV reactor is efficient in reducing the infectivity of Cryptosporidium parvum oocysts, one of the most resistant micro-organisms present in environmental waters.

In vitro efficacy of nitro- and halogeno-thiazolide/thiadiazolide derivatives against Sarcocystis neurona.

Sarcocystis neurona is an obligate intracellular parasite that causes equine protozoal myeloencephalitis (EPM). The aim of this work was to document inhibitory activities of nitazoxanide (NTZ, [2-acetolyloxy-N-(5-nitro 2-thiazolyl) benzamide]) and new thiazolides/thiadiazolides on S. neurona in vitro development, and investigate their structure-activity relationships. S. neurona was grown in bovine turbinate cell cultures. At concentrations varying from 1.0 to 5.0mg/L, nitazoxanide and 21 of 32 second generation thiazolide/thiadiazolide agents exerted a > or =95% maximum inhibition on S. neurona development. Most active agents were either NO(2) or halogen substituted in position 5 of their thiazole moiety. In contrast, other 5-substitutions such as hydrogen, methyl, SO(2)CH(3), and CH(3) negatively impacted activity. Compared with derivatives with an acetylated benzene moiety, deacetylated compounds which most probably represent primary metabolites exhibited similar inhibitory activities. Present data provide the first evidence of in vitro inhibitory activities of nitazoxanide and new thiazolides/thiadiazolides on S. neurona development. Active halogeno-thiazolide/thiadiazolides may provide a valuable nitro-free alternative to nitazoxanide for EPM treatment depending on further evaluation of their in vivo activities.

Role of glutamate transporters in corticostriatal synaptic transmission.

High-affinity glutamate transporters (GTs) play a major role in controlling the extracellular level of this excitatory neurotransmitter in the CNS. Here we have characterized, by means of in vitro patch-clamp recordings from medium spiny neurons (MSNs), the role of GTs in regulating corticostriatal glutamatergic synaptic transmission in the adult rat. Charge transfer and decay-time, but not amplitude, of excitatory postsynaptic currents (EPSCs) were enhanced by dl-threo-beta-benzyloxyaspartate (TBOA), a broad inhibitor of GTs. Moreover, TBOA also potentiated currents induced by high-frequency stimulation (HFS) protocols. Interestingly, the effect of TBOA on EPSCs was lost when MSNs were clamped at +40 mV, a condition in which neuronal GTs, that are voltage-dependent, are blocked. However, in this condition TBOA was still able to enhance HFS-induced currents, suggesting that glial GT's role is to regulate synaptic transmission when glutamate release is massive. These data suggest that neuronal GTs, rather than glial, shape EPSCs' kinetics and modulate glutamate transmission at corticostriatal synapse. Moreover, the control of glutamate concentration in the synaptic cleft by GTs may play a role in a number of degenerative disorders characterized by the hyperactivity of corticostriatal pathway, as well as in synaptic plasticity.

Co-infected C57BL/6 mice mount appropriately polarized and compartmentalized cytokine responses to Litomosoides sigmodontis and Leishmania major but disease progression is altered.

This study examines the capacity of the mammalian host to fully compartmentalize the response to infection with type 1 vs. type 2 inducing organisms that infect different sites in the body. For this purpose, C57BL/6 mice were infected with the rodent filarial nematode Litomosoides sigmodontis followed by footpad infection with the protozoan parasite Leishmania major. In this host, nematode infection is established in the thoracic cavity but no microfilariae circulate in the bloodstream. We utilized quantitative ELISPOT analysis of IL-4 and IFN-gamma producing cells to assess cytokine bias and response magnitude in the lymph nodes draining the sites of infection as well as more systemic responses in the spleen and serum. Contrary to other systems where co-infection has a major impact on bias, cytokine ratios were unaltered in either local lymph node. The most notable effect of co-infection was an unexpected increase in the magnitude of the IFN-gamma response to L. major in mice previously infected with L. sigmodontis. Further, lesion development was significantly delayed in these mice. Thus, despite the ability of the immune system to appropriately compartmentalize the immune response, interactions between responses at distinct infection sites can alter disease progression.

[Cerebral oxidative stress: are astrocytes vulnerable to low intracellular glutamate concentrations? Consequences for neuronal viability]. / Stress oxydatif cérébral : les astrocytes sont-ils vulnérables aux faibles concentrations intracellulaires de glutamate? Implications sur la survie neuronale.

This review describes reactive oxygen species (ROS), their production and effects on crucial biological molecules, the different lines of defense against oxidative stress, with particular attention to glutathione, the main antioxidant in the brain, which neuronal synthesis seems to be dependent on astrocytic precursors. It also focuses on the different ways by which glutamate may induce oxidative stress in the brain. The different mechanisms leading to ROS production, activated during the excitotoxic cascade, are described. Oxidative glutamate toxicity is also briefly described. A novel form of oxidative glutamate toxicity by depletion of transported glutamate that we recently evidenced is detailed. This toxicity induced by pharmacological reversal of glutamate transport, which mimics glutamate transport reversal occurring in ischemia, involves glutathione depletion and oxidative stress, leading to delayed death of cultured striatal astrocytes differentiated by dibutyryl-cAMP, probably through apoptotic processes. Evidence suggesting that this oxidative glutamate toxicity by depletion of transported glutamate is very likely occurring in vivo and its consequences on neuronal survival are discussed.

Chronic L-DOPA treatment increases extracellular glutamate levels and GLT1 expression in the basal ganglia in a rat model of Parkinson's disease.

There is growing experimental evidence for the implication of glutamate-mediated mechanisms both in the pathophysiology of Parkinson's disease and in the development of dyskinesias with long-term administration of L-3,4-dihydroxyphenylalanine (L-DOPA). However, the impact of this treatment on glutamate transmission in the basal ganglia has been poorly investigated. In this study, we examined the effects of 6-hydroxydopamine-induced lesion of nigral dopamine neurons with or without subsequent chronic L-DOPA treatment on several parameters of glutamate system function in the rat striatum and substantia nigra pars reticulata. All the lesioned animals treated with L-DOPA developed severe dyskinesias. Extracellular glutamate levels, measured by microdialysis in freely moving conditions, and gene expression of the glial glutamate transporter GLT1, assessed by in situ hybridization, were unaffected by dopamine lesion or L-DOPA treatment alone, but were both markedly increased on the lesion side of rats with subsequent L-DOPA treatment. No change in the expression of the vesicular glutamate transporters vGluT1 and vGluT2 was measured in striatum. These data show that chronic L-DOPA treatment leading to dyskinesias increases basal levels of glutamate function in basal ganglia. The L-DOPA-induced overexpression of GLT1 may represent a compensatory mechanism involving astrocytes to limit glutamate overactivity and subsequent toxic processes.

[Penicillium chrysogenum endophthalmitis: a case report]. / Endophtalmie à Penicillium chrysogenum: à propos d'un cas.

We report a case of Penicillium chrysogenum endophthalmitis after penetrating ocular trauma in a 9-year-old child, describing the initial management and the therapeutic adaptation after biopsy culture. After a review of endophthalmitis treatment, we discuss mycotic endophthalmitis treatment and recommend the use of intravitreal antibiotics. In this case, we used amphotericin B to treat the fungal disorder with success.

[Ocular defects associated with a duplication of the distal part of the long arm of chromosome 1: a case report]. / Anomalies ophtalmologiques associées à une duplication d'un segment distal du bras long du chromosome 1.

The authors report a case of de novo duplication 1q32-qter present in a patient with dysmorphic syndrome and developmental delay. This article describes the eighth case of partial trisomy 1q32-qter "pure", without chromosomal abnormalities. In the literature, a dysmorphic "syndrome" is described for trisomy 1q32-qter: hypertelorism, low set and malformed ears, prominent forehead, long philtrum, antimongoloid slanting, foot and digital malformations, cardiovascular abnormalities, urogenital abnormalities, and mental retardation. The ocular defects described in previously reported cases include: cataract, strabismus, hypoplasia of the optic disk, microphthalmia, epicanthal folds, ptosis, persistent tunica vasculosa lentis, and hyaloid vessels, but this seems to be nonspecific of this chromosomal abnormality.

[Bilateral exophthalmos diabetes insipidus: Erdheim-Chester disease. Clinical and radiological findings]. / Exophtalmie bilatérale-diabète insipide: la maladie d'Erdheim-Chester.

The authors report a case of a 61-year-old man presenting bilateral exophthalmos and diabetes insipidus. A retro-orbital biopsy revealed nonspecific fibrocollagenic infiltration. The diagnosis of Erdheim-Chester disease was evoked when a multivisceral affection (retroperitoneal and mediastinal periaortic fibrosis) with specific bone localization became evident. The histopatholgical study of a bone biopsy showed xanthogranulomatous infiltration. The patient died a few months later of an intercurrent infection.

Nigrostriatal denervation does not affect glutamate transporter mRNA expression but subsequent levodopa treatment selectively increases GLT1 mRNA and protein expression in the rat striatum.

There is growing evidence that the loss of the nigrostriatal dopaminergic neurones induces an overactivity of the corticostriatal glutamatergic pathway which seems to be central to the physiopathology of parkinsonism. Moreover, glutamatergic mechanisms involving NMDA receptors have been shown to interfere with the therapeutical action of levodopa. Given the key role played by uptake processes in glutamate neurotransmission, this study examined the effects of nigrostriatal deafferentation and of levodopa treatment on the striatal expression of the glutamate transporters GLT1, GLAST and EAAC1 in the rat. No significant changes in striatal mRNA levels of these transporters were detected after either levodopa treatment (100 mg/kg; i.p., twice a day for 21 days) or unilateral lesion of the nigrostriatal pathway by intranigral 6-hydroxydopamine injection. In contrast, animals with the lesion subsequently treated with levodopa showed a selective increase (36%) in GLT1 mRNA levels in the denervated striatum versus controls. These animals also showed increased GLT1 protein expression, as assessed by immunostaining and western blotting. These data provide the first evidence that levodopa therapy may interfere with striatal glutamate transmission through change in expression of the primarily glial glutamate transporter GLT1. We further suggest that levodopa-induced GLT1 overexpression may represent a compensatory mechanism preventing neurotoxic accumulation of endogenous glutamate.

Impaired glutamate uptake in the R6 Huntington's disease transgenic mice.

Huntington's disease (HD) is a late-onset neurodegenerative disease for which the mutation is CAG/polyglutamine repeat expansion. The R6 mouse lines expressing the HD mutation develop a movement disorder that is preceded by the formation of neuronal polyglutamine aggregates. The phenotype is likely caused by a widespread neuronal dysfunction, whereas neuronal cell death occurs late and is very selective. We show that a decreased mRNA level of the major astroglial glutamate transporter (GLT1) in the striatum and cortex of these mice is accompanied by a concomitant decrease in glutamate uptake. In contrast, the expression of the glutamate transporters, GLAST and EAAC1, remain unchanged. The mRNA level of the astroglial enzyme glutamine synthetase is also decreased. These changes in expression occur prior to any evidence of neurodegeneration and suggest that a defect in astrocytic glutamate uptake may contribute to the phenotype and neuronal cell death in HD.

Litomosoides sigmodontis in mice: reappraisal of an old model for filarial research.

Onchocerciasis and lymphatic filariasis (LF) are major causes of severe morbidity and considerable socio-economic problems throughout the tropics. Vector control and mass chemotherapy have helped to control these infections in some regions, but the temporary success of such measures argues strongly for the development of vaccines. Success in such a venture will require detailed knowledge of protective immune responses in conjunction with the identification of target antigens. By comparison with other important parasitic infections, such as schistosomiasis and leishmaniasis, work on the development of vaccines for onchocerciasis and LF has been constrained because of the difficulties of producing cyclical and patent filarial infection in laboratory mice. Wolfgang Hoffmann and colleagues here outline the opportunities presented by the rodent filaria Litomosoides sigmodontis for filarial research.

Drastic reduction of a filarial infection in eosinophilic interleukin-5 transgenic mice.

In order to establish the role of eosinophils in destroying parasites, transgenic mice have been used in experimental helminthiases but not in filariasis. Litomosoides sigmodontis offers a good opportunity for this study because it is the only filarial species that completes its life cycle in mice. Its development was compared in transgenic CBA/Ca mice overexpressing interleukin-5 (IL-5) and in wild-type mice following subcutaneous inoculation of 40 infective larvae. An acceleration of larval growth was observed in the IL-5 transgenic mice. However, the recovery rate of adult worms was considerably reduced in these mice, as evidenced 2 months postinoculation (p.i.). The reduction occurs between days 10 and 30 p.i. in the coelomic cavities. As early as day 10, spherical aggregates of eosinophils and macrophages are seen attached on live developing larvae (always similarly localized on the worm) in both wild-type and transgenic mice. However, on day 60 p.i., granulomas were found in the transgenic mice only, probably because of the higher density of eosinophils. Furthermore, on day 30 p.i., young filariae are seen trapped in granulomas, some of them surrounded by Splendore-Hoeppli deposits, which illustrates the release of the major basic protein by eosinophils. The high protection rate obtained (65%) is similar to that observed previously in BALB/c mice following vaccination with irradiated larvae. Both protocols have a common factor, the high production of IL-5 and eosinophilia. However, protection occurs later in primary infected transgenic mice because specific antibodies are not yet present at the time of challenge.

Interleukin-5 is essential for vaccine-mediated immunity but not innate resistance to a filarial parasite.

The study of protective immune mechanisms effective against filarial nematodes has been hampered by the inability of these important human pathogens to infect laboratory mice. Recently, Litomosoides sigmodontis, a natural parasite of rats, has been developed as a valuable model for the study of filarial infection. BALB/c mice are fully susceptible to infection with L. sigmodontis third-stage larvae and develop patent infection. In contrast, mice on the C57BL background are resistant, and parasites undergo only a single molt and do not mature to adulthood. We used interleukin-5 (IL-5)-deficient mice on the C57BL/6 background to address the role of IL-5 and eosinophils in the innate resistance of C57BL/6 mice. We found no differences in parasite survival between IL-5-deficient and C57BL/6 mice. However, when these mice were used for the analysis of vaccine-mediated immunity, a critical role for IL-5 was elucidated. Mice genetically deficient in IL-5 were unable to generate a protective immune response when vaccinated with irradiated larvae, whereas C57BL/6 mice were fully protected from challenge infection. These studies help to clarify the highly controversial role of eosinophils in filarial infection.

Parasitology and immunology of mice vaccinated with irradiated Litomosoides sigmodontis larvae.

This study was performed with Litomosoides sigmodontis, the only filarial species which can develop from the infective larvae to the patent phase in immunocompetent laboratory BALB/c mice. Parasitological features and immune responses were analysed up to 3 months before and after challenge inoculation, by comparing 4 groups of mice: vaccinated challenged, challenged only, vaccinated only, and naive mice. Male larvae were very susceptible to irradiation and only female irradiated larvae survived in vivo. Protection, assessed by a lower recovery rate, was confirmed and was established within the first 2 days of challenge. This early reduction of the recovery rate in vaccinated challenged mice was determined by their immune status prior to the challenge inoculation. This was characterized by high specific IgM and IgG subclass (IgG1, IgG2a and IgG3) levels, high specific IL-5 secretion from spleen cells in vitro and a high density of eosinophils in the subcutaneous connective tissue. Six h after the challenge inoculation, most tissue eosinophils were degranulated in vaccinated challenged mice. Thus, in the protocol of vaccination described, protection appeared mainly to result from the stimulation of a Th2 type response and eosinophils seemed to be the main effectors for the increased killing of infective larvae in vaccinated challenged mice. Two months after challenge inoculation, the percentage of microfilaraemic mice was lower in vaccinated challenged mice as a consequence of this overall reduction in the worm load. In both vaccinated challenged and challenged only groups, the in vitro splenocyte proliferative capacity was reduced in microfilaraemic mice.