[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.

[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.

[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.

[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.

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.

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.

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.

Effects of PKA and PKC modulators on high affinity glutamate uptake in primary neuronal cell cultures from rat cerebral cortex.

In this study, the effects of various agents known to alter protein phosphorylation, via protein kinase C or A, on high affinity glutamate uptake were investigated in primary neuronal cell cultures of rat cerebral cortex. Incubating the culture dishes with chelerythrine or H89 (N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide), which inhibit PKC and PKA, respectively, dramatically decreased the glutamate uptake in a dose-dependent manner. Saturation kinetic analysis showed that chelerythrine and H89 decreased the Vmax (chelerythrine: -61%, P < 0.06; -59%, P < 0.05) without affecting the Km of the transport process as compared to the control values. These inhibitory effects were counteracted by the corresponding protein kinase activators, i.e. PMA (phorbol-12-myristate 13-acetate) in the case of PKC and forskolin in the case of PKA, although these protein kinase activators alone did not significantly affect the glutamate uptake. These results provide evidence that, in primary cultures of neuronal cells, the high affinity glutamate uptake may be regulated by both PKA and PKC-mediated phosphorylation processes.

Human eosinophils express bcl-2 family proteins: modulation of Mcl-1 expression by IFN-gamma.

The expression of the Bcl-2 family proteins Bax, Mcl-1, Bcl-2, and Bcl-xL, was examined in human peripheral blood eosinophils or in umbilical-cord-blood-derived eosinophils. Immunoblot analysis disclosed high amounts of the proapoptotic factor Bax in freshly purified eosinophils of both types. Although cord-blood-derived eosinophils expressed easily detectable levels of Mcl-1, Bcl-2, and Bcl-xL, only traces or no expression of these three antiapoptotic proteins were found in peripheral blood eosinophils. Incubation of both eosinophil types for 1 to 3 days in a cytokine-deprived medium led to apoptosis, without changes in the expression of Bax, Mcl-1, Bcl-2, or Bcl-xL. Although addition of interleukin-5 or interferon-gamma (IFN-gamma) to the culture medium increased the survival of both eosinophil types, a rise in the levels of Mcl-1 was observed only in IFN-gamma-treated cord-blood eosinophils. Together, these results indicate that human eosinophils have a specific profile of Bcl-2-family protein expression that depends on their maturation status and may be modulated by stimuli that influence their survival.

Nitric oxide pathway is induced by Fc epsilon RI and up-regulated by stem cell factor in mouse mast cells.

Murine stem cell factor (SCF) induces the differentiation of mucosal mast cells (MMC) into connective tissue mast cells (CTMC) and potentiates mediator release induced by aggregation of high-affinity IgE receptors (Fc epsilon RI). In the present work, we investigated the effect of Fc epsilon RI aggregation on nitric oxide (NO) pathway induction in the different subsets of mast cells, as well as the contribution of SCF in this induction. Inducible NO synthase (iNOs) expression was not evidenced in non-stimulated MMC obtained by culture of hematopoietic progenitors in the presence of interleukin-3, whereas IgE-antigen-stimulated MMC expressed iNOs mRNA and protein and synthesized nitrites. Long-term treatment of MMC with SCF, allowing them to differentiate into CTMC, induced iNOs expression in non-stimulated cells and up-regulated iNOs expression and generation of NO derivatives induced by IgE-antigen stimulation. Thus, NO derivatives generated by mast cells could participate in inflammatory reactions during allergic stimulation.

Inducible nitric oxide synthase and proinflammatory cytokine expression by human keratinocytes during acute urticaria.

BACKGROUND: IgE/allergen-dependent activation of skin mast cells is involved in acute urticaria and leads to their IL-4 release. Previously we have demonstrated in vitro the induction of the low-affinity receptor for IgE (CD23/Fc epsilon RII) in human keratinocytes (HK) upon stimulation with IL-4. In addition, we have observed that ligation of CD23 on keratinocytes induced type II nitric oxide synthase (iNOS), leading to the release of nitric oxide (NO) and proinflammatory cytokines (TNF-alpha, IL-6). According to these in vitro data, we explored whether keratinocytes could also express iNOS, TNF-alpha, IL-6, and CD23 in acute urticaria, an in vivo model in which activation of mast cells by IgE/allergen immune complexes is involved. MATERIALS AND METHODS: INOS, TNF-alpha, IL-6, and CD23 expression by keratinocytes was studied in acute urticaria (n = 11) in biopsies from lesional and autologous normal skin by immunohistochemistry, in situ hybridization, or RT-PCR. Nitrites and TNF-alpha synthesis were assayed in supernatants of cultured lesional keratinocytes. RESULTS: INOS mRNA expression was demonstrated with RT-PCR in 10 biopsies out of 11 sections of acute urticaria lesional skin. Immunohistochemistry showed that this iNOS positivity originated from keratinocytes located close to the dermoepidermal junction; TNF-alpha and IL-6 mRNA transcription was observed in all but one iNOS+ biopsy. Immunostaining and in situ hybridization with CD23-specific probes were strong in all but one iNOS+ skin biopsy. Noninflamed autologous skin was negative for iNOS (except for a weak positivity in one case), cytokines, and CD23. CONCLUSION: The colocalization of iNOS, proinflammatory cytokines, and CD23 within keratinocytes in acute urticaria demonstrates that these cells play an important role in the initiation and maintenance of the inflammatory reaction during this disease in humans through activation of the iNOS pathway by CD23 ligation with IgE/allergen immune complexes.

CD23-mediated nitric oxide synthase pathway induction in human keratinocytes is inhibited by retinoic acid derivatives.

Retinoids exert various functions including anti-proliferative and anti-inflammatory effects on many cell types including keratinocytes and are widely used in skin diseases, such as psoriasis and acne. We have previously shown that human keratinocytes express low affinity immunoglobulin E receptor (FcepsilonRII/CD23) when stimulated with interleukin-4. Immunoglobulin E ligates CD23 and induces the production of nitrites (reflecting the mobilization of the nitric oxide [NO]-pathway) and tumor necrosis factor-alpha by human keratinocytes. Here, 13-cis and all-trans retinoic acid (RA) were shown to reduce the production of nitrites by immunoglobulin E-activated keratinocytes by 80% in a time- and concentration-dependent fashion. As a consequence, RA derivatives also reduced the production of tumor necrosis factor alpha by these cells by 70%. The level of inducible NO synthase activity in activated human keratinocytes was significantly decreased upon treatment of the cells with RA derivatives (inhibition by 60% of the mean inducible NO synthase activity with 13-cis RA, 2 microM). Treatment for 24 h with RA derivatives almost completely abolished transcription of inducible NO synthase-specific mRNA in activated keratinocytes. Therefore, RA derivatives downregulate tumor necrosis factor-alpha release and the NO-transduction pathway through the inhibition of inducible NO synthase transcription. Together, our data provide evidence for inhibition of the NO-pathway by 13-cis and all-trans retinoic acid on CD23-activated human keratinocytes. These data may clarify the mechanism of the anti-inflammatory activity of RA derivatives in skin diseases.

Activation of the adenylate cyclase-dependent protein kinase pathway increases high affinity glutamate uptake into rat striatal synaptosomes.

This study examined the effects of various agents known to alter protein phosphorylation through protein kinase A or C on high affinity glutamate uptake measured in vitro on rat striatal homogenates. Incubation of synaptosomes with the phosphatase inhibitor, okadaic acid, dramatically increased glutamate uptake indicating that underlying phosphorylation mechanisms may be involved in the regulation of this transport process. The protein kinase C activator, phorbol-12,13-dibutyrate, or inhibitor, staurosporine, did not significantly modify glutamate uptake. In contrast, forskolin, which activates adenylate cyclase, induced a dose-dependent increase in glutamate uptake. Saturation kinetic analysis indicated that forskolin increased the Vmax without modifying the Km of the transport process as compared to control values. The effect of forskolin was mimicked by dibutyryl adenosine monophosphate, an analog of cAMP which activates protein kinase A, and counteracted by high doses of N-[2-(methylamino) ethy1]-5-isoquinoline sulfonamide, a protein kinase A inhibitor. These results suggest that an adenylate cyclase-dependent protein kinase may be involved in the post-translational regulation of glutamate transporters.

Granulocyte macrophage colony stimulating factor induces Fc epsilon RII/CD23 expression on normal human polymorphonuclear neutrophils.

Three major molecules have been recognized as IgE-binding structures on hematopoietic cells: the heterotrimeric high-affinity receptor for IgE (Fc epsilon RI), the low-affinity receptor for IgE (Fc epsilon RII/CD23) and the Mac-2/IgE-binding protein (epsilon BP). The latter has been shown to be expressed on polymorphonuclear neutrophils (PMN), where it regulates IgE-dependent activation. Experiments were undertaken to determine whether the IgE-binding capacity of PMN is mediated exclusively by this molecule. No detectable binding of human myeloma IgE to unstimulated PMN from normal volunteers could be evidenced. In contrast, PMN stimulated with granulocyte macrophage colony stimulating factor (GM-CSF) (500 U/ml) for 24 h displayed positive IgE binding. This binding was significantly inhibited in the presence of mAb directed against Mac-2/epsilon BP and also in the presence of anti-CD23 mAb, but not of anti-Fc epsilon RI mAb or isotype-matched controls. By flow cytometry, CD23 expression was detected on GM-CSF-primed PMN by several anti-CD23 mAb, including EBVCS-5, BB10 or Mab135, which recognize different epitopes. CD23 was also evidenced by immunocytochemistry in GM-CSF-primed PMN. By in situ hybridization, GM-CSF-treated PMN exhibited a hybridization signal for CD23 mRNA and the presence of the CD23b isoform-specific mRNA was detected by RT-PCR. These findings indicate that PMN can synthesize CD23 molecules under GM-CSF induction. This strong CD23 expression might be of physiopathological relevance in IgE-dependent activation during allergic processes.

[Experimental radiosurgery in rats using gamma a "gamma knife". Description of a stereotactic device for small laboratory animals]. / Radiochirurgie expérimentale chez le rat par "gamma knife". Description d'un cadre stéréotaxique pour le petit animal de laboratoire.

To allow the experimental use in rats of a Gamma Knife Radiosurgical Unit, a stereotactic device adapted from the conventional Kopf's device was developed. To control the accuracy of the coordinate system based on the De Groot's rat stereotactic atlas, experimental radiosurgical lesions were made on the left striatum. The isodose curve distribution of the 4 mm collimator was calculated with the dose planning software used in Gamma Knife and superimposed on the left striatum target. Doses of 200 Gy were administered to the left striatum in six rats. The results were evaluated 21, 34 and 47 days later. At 34 and 47 days necrotic lesions were exactly as targeted. In a second group of 48 rats receiving a doses of 100 Gy, no lesions were observed after 7, 15, 24, 31, 45 days. However, in all rats sacrificed 59, 72 and 90 days after day radiation, a necrotic lesion was always present and confirmed that at each time the lesions were precisely targeted. This apparatus allows precise and reproducible gamma irradiation lesion in rat brain without expensive and time consuming imaging techniques. This device provides a useful system to observe the experimental effects of radiosurgery on the central nervous system in rats.

Interleukin-10 inhibits IgE-mediated nitric oxide synthase induction and cytokine synthesis in normal human keratinocytes.

Human keratinocytes (HK) generate nitric oxide (NO) and proinflammatory mediators following activation with either IgE/anti-IgE immune complexes or a combination of lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma). Recently, interleukin-10 (IL-10) has been shown to down-regulate various inflammatory responses and to be secreted by lymphocytes and dendritic cells during skin inflammatory reactions. We show here that IL-10 down-regulates the production of tumor necrosis factor (TNF)-alpha and IL-6 by activated HK. Also, induction of inducible nitric oxide synthase (iNOS) expression in HK by IgE/anti-IgE or LPS/IFN-gamma is significantly reduced by the addition of IL-10. This effect is dose dependent and correlates with reduction of iNOS mRNA production and enzyme level. Therefore, IL-10 down-regulates NO-mediated HK inflammatory responses and may thus participate in the regulation of the skin immune network.

Involvement of cyclic nucleotides in the immunomodulatory effects of nitric oxide on murine mast cells.

Nitric oxide (NO) is synthesized by various cells involved in inflammatory reactions and may then act on mast cells. In the present work, we attempted to clarify the role of this molecule on the proliferation and IgE-mediated activation of mouse bone-marrow-derived mast cells obtained by culture in the presence of IL-3 (BMMC). Treatment of BMMC with increasing concentrations of sodium nitroprusside (SNP) induced a dose-dependent inhibition of 3H-thymidine incorporation (IC50 = 50 microM) without affecting cell survival under 100 microM. Furthermore, nitric oxide dramatically decreased beta-hexosaminidase and TNF-alpha release induced by Fc epsilon RI ligation on BMMC (respectively 45 and 57% for 100 microM). These inhibitory effects are mediated at least in part through enhancement of intracellular cyclic nucleotides levels since: 1) intracellular cGMP and cAMP levels increased within minutes after NO treatment, 2) treatment of BMMC with a cAMP analogue induced antiproliferative effect on BMMC and 3) pretreatment of BMMC with a cAMP antagonist partly reversed the inhibitory activity of SNP.

Involvement of Fc epsilon RII/CD23 and L-arginine dependent pathway in IgE-mediated activation of human eosinophils.

Eosinophils display various receptors for immunoglobulin E (IgE) including the high affinity receptor for IgE (Fc epsilon RI), CD23 (Fc epsilon RII), and Mac-2/epsilon BP. We attempted here to clarify the role of these receptors in IgE-mediated activation of eosinophils from normal human bone marrow cultures. Pretreatment of eosinophils with IL-4 is required for IgE/anti-IgE-mediated stimulation of TNF-alpha and peroxydes production. TNF-alpha release from eosinophils was also induced following ligation of CD23 and to a lesser extent with anti-Mac-2, while Fc epsilon RI-ligation had no effect. IgE/anti-IgE effect dramatically decreased when eosinophils were pretreated with Fab fragments of CD23-mAb. In addition, this effect could also be reversed by inhibiting CD23-dependent nitric oxide pathway by NG-monomethyl-L-arginine. Nitric oxide chemical donor, SIN-1, induced TNF-alpha release from eosinophils. CD23 and nitric oxide pathway are thus involved in IgE-mediated stimulation of normodense human eosinophils.

IgE-dependent activation of Fc epsilon RII/CD23+ normal human keratinocytes: the role of cAMP and nitric oxide.

Epidermal keratinocytes (EK) are exposed to multiple inflammatory stimuli and paracrine factors secreted by various dermal cells (lymphocytes, mast-cells, macrophages, fibroblasts) during wounding, cutaneous allergy and infections. We have previously demonstrated that following stimulation with interleukin-4 (IL-4) or interferon-gamma, human EK express the low affinity receptor for IgE (Fc epsilon RII/CD23) on their surface. In the present study, we showed that the ligation of CD23 by IgE/anti-IgE immune complexes or specific monoclonal antibody, induces a dose-dependent release of interleukin-6 and tumor necrosis factor-alpha from EK. CD23-ligation activates the nitric oxide-dependent pathway, as demonstrated by the high levels of nitrites released in cell supernatants, and the accumulation of intracellular cyclic nucleotides in EK. These second messengers are required for IgE-dependent stimulation of cytokine production by these cells, as this is completely abolished by cAMP or NO synthase antagonists. Human epithelial keratinocytes may thus participate in IgE-mediated immune responses, through their ability to express functional CD23 antigen.

Specific ligation of the HIV-1 viral envelope protein gp120 on human CD34+ bone marrow-derived progenitors.

The precise mechanisms of hematologic abnormalities observed during HIV infection remain unknown. In vitro experiments performed by various authors concerning the HIV toxicity on bone marrow-derived precursors did not allow them to determine whether this toxicity could be mediated through direct or non-direct effects, since it is today unclear if gp120 possesses a direct hematotoxic effect on human bone marrow progenies. The aim of our study was to determine whether labelled gp120 could specifically bind to the membrane of purified human normal CD34+ cells and to investigate the in vitro effect of the gp120 on their growth. To answer these questions, human CD34+ cells were purified from normal bone marrow samples, then labelled with monoclonal antibodies directed either against CD4 antigen or CD34 antigen and/or with FITC labelled gp120 and analyzed by FACS. Our results demonstrate the presence of about 5% of CD4+CD34+ cells and of nearly 12% of CD34+gp120+ precursors. Together with our results concerning the in vitro inhibitory effect of gp120 on the growth of the same purified CD34+ precursors, our data demonstrated the direct hematotoxic activity of HIV-derived gp120 and the possible HIV infection of hematopoietic progenitors through the interaction of gp 120 with CD34+ cell surface.