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The treatment of primary vitreoretinal lymphoma (PVRL) remains controversial regarding the use of local, systemic, or combined treatments. The aim of this study was to analyze the efficacy and toxicity of intravenous high-dose methotrexate (IV HD-MTX) based systemic therapy in a uniformly treated population of PVRL patients. From a nationwide French database, we retrospectively selected 59 patients (median age: 70 years, median Karnofsky Performance Status: 90%) with isolated PVRL at diagnosis who received first-line treatment with HD-MTX between 2011 and 2018. 8/59 patients also received a local treatment. No deaths or premature discontinuations of MTX due to toxicity were reported. A complete response was obtained in 40/57 patients after chemotherapy. Before treatment, IL-10 was elevated in the aqueous humor (AH) or in the vitreous in 89% of patients. After treatment, AH IL-10 was undetectable in 87% of patients with a CR/uCR/PR and detectable in 92% of patients with PD/SD. After a median follow-up of 61 months, 42/59 (71%) patients had relapsed, including 29 isolated ocular relapses as the first relapse and a total of 22 brain relapses. The median overall survival, progression-free survival, ocular-free survival and brain-free survival were 75, 18, 29 and 73 months, respectively. IV HD-MTX based systemic therapy as a first-line treatment for isolated PVRL is feasible, with acceptable toxicity, even in an elderly population. This strategy seems efficient to prevent brain relapse with prolonged overall survival. However, the ocular relapse rate remains high. New approaches are needed to improve local control of this disease, and ocular assessment could be completed by monitoring AH IL-10.
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Antimetabólitos Antineoplásicos/uso terapêutico , Linfoma Intraocular/tratamento farmacológico , Metotrexato/uso terapêutico , Neoplasias da Retina/tratamento farmacológico , Administração Intravenosa , Adulto , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/efeitos adversos , Feminino , Humanos , Linfoma Intraocular/diagnóstico , Masculino , Metotrexato/administração & dosagem , Metotrexato/efeitos adversos , Pessoa de Meia-Idade , Prognóstico , Neoplasias da Retina/diagnóstico , Resultado do TratamentoRESUMO
INTRODUCTION: The aim of the study was to assess the microperimetric consequences of active internal limiting membrane (ILM) peeling during idiopathic epimacular membrane (IEMM) surgery. MATERIALS AND METHODS: This retrospective monocentric study included 32 eyes of 31 consecutive patients who underwent IEMM surgery. Internal limiting membrane integrity was assessed by ILM Blue staining after IEMM removal: peeling was spontaneous (Group S) or active (Group A). Preprocedure and postprocedure (1 and 6 months) examinations were performed using visual acuity determination, spectral domain optical coherence tomography and microperimetry. RESULTS: Twenty-two eyes had an "active ILM peeling" and 10 a "spontaneous ILM peeling." Both groups had comparable and significant improvements in visual acuity 6 months after surgery (+1.82 lines [+9 letters] [Group A] and +1.51 lines [+8 letters] [Group S], P < 0.01) associated with a significant reduction in optical coherence tomography central thickness (-99.9 µm [Group A], P < 0.01 and -62.2 µm [Group S], P = 0.05). Six months after surgery, the microperimetry showed more numerous and deeper microscotomas in the Group A than in the Group S (change in the number of microscotomas: 2.09 vs. -0.10, P = 0.06; change in deficit severity score: 13.18 dB vs. -2 dB, P < 0.01 for Group A and S, respectively). The number of microscotomas and also severity were increased in 63.6% of Group A patients and in only 20% of Group S patients. Microscotomas were most frequently located in IEMM and/or ILM areas. DISCUSSION: Internal limiting membrane peeling has progressively become generalized in IEMM surgery to reduce recurrences. This additional procedure does not change the postoperative visual acuity but increases the development of deeper microscotomas. The real impact on the quality of vision remains unclear. CONCLUSION: Active ILM peeling in IEMM surgery may be responsible for visual impairment related to its microtraumatic effects.
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Membrana Basal/cirurgia , Membrana Epirretiniana/cirurgia , Procedimentos Cirúrgicos Oftalmológicos/efeitos adversos , Escotoma/etiologia , Campos Visuais , Idoso , Feminino , Seguimentos , Humanos , Masculino , Estudos Retrospectivos , Escotoma/diagnóstico , Escotoma/fisiopatologia , Tomografia de Coerência Óptica , Acuidade Visual/fisiologia , Testes de Campo Visual , VitrectomiaRESUMO
BACKGROUND: This case report explores the relationship between genetics and phenotypic variability in autosomal dominant vitreoretinochoroidopathy (ADVIRC). The study focuses on a case presenting a novel mutation in the BEST1 gene and its phenotype in the case's relatives, shedding light on the structural and functional intricacies underlying this rare ophthalmologic disorder. CASE PRESENTATION: A 33-year-old female presented for consultation with a history of bilateral retinal damage accompanied by a complaint of decreased visual acuity, progressive visual field deficit, and night blindness over the past year. Ophthalmic examination revealed a distinctive phenotype, including fibrillar vitreous, pigmented cells, and atrophic hyperpigmented retina in the periphery which was suggestive of a diagnosis of ADVIRC. Genetic testing revealed a heterozygous c.1101-1 G>T variant in BEST1, a novel splice site mutation. Functional analysis confirmed its impact on pre-mRNA splicing, resulting in an in-frame deletion (p(Ser367_Asn579del)). Family investigation revealed varying degrees of ophthalmologic impairment in the patient's mother and half-sister, both carrying the same mutation. CONCLUSIONS: This case report provides the first clinical description of the c.1101-1 G>T mutation in the BEST1 gene associated with ADVIRC. The presence of intrafamilial variability, as evidenced by the differing clinical features observed in the index case and her half-sister, suggests the potential involvement of mechanisms influencing phenotype expression.Abbreviation: ADVIRC : autosomal dominant vitreoretinochoroidopathy; RNA : ribonucleic acid; RPE : retinal pigment epithelium.
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PURPOSE: To assess the efficacy and safety of 0.19-mg fluocinolone acetonide (FAc) intravitreal implant (Iluvien®) in treating chronic postoperative cystoid macular edema (PCME) after pars plana vitrectomy. DESIGN: Retrospective multicentric case series in clinical settings. SUBJECTS: Patients with chronic PCME who underwent vitrectomy in tertiary care centers in France. All eyes had a documented good response to the DEX implant prior to FAc implantation. METHODS: Review of charts and OCT scans of patients treated with a FAc intravitreal implant. MAIN OUTCOME MEASURES: The primary endpoints were the best-corrected visual acuity (BCVA) and central retinal thickness (CRT). Secondary endpoints were the intraocular pressure (IOP); proportion of patients maintaining a BCVA ≥20/40; need for additional non-study treatment; differences between eyes that underwent a single and multiple surgeries and OCT biomarkers of better BCVA. RESULTS: Forty-nine eyes of 49 patients with a mean follow-up of 24.5 ± 3.9 months were included. The mean BCVA increased from 0.40 ± 0.26 logMAR at baseline to 0.32 ± 0.24 logMAR at month 24 (M24) (p=0.0035). The mean CRT decreased from 409.37 ± 139.43 µm at baseline to 340 ± 91 µm at M24 (p=0.0001). The mean IOP was 14.0 ± 4 mmHg at baseline and remained stable at 14.03 ± 4.1 mmHg at M24 (p=0.99). During the follow-up, the IOP exceeded 21 mmHg in 9 eyes. The IOP rise was controlled with topical therapy in all eyes except one, which required cyclophotocoagulation. The BCVA was ≥20/40 in 47% of eyes (95% CI: 34%-61%) at baseline and in 58% of eyes at M24 (95% CI: 41%-73%). At M18, the likelihood of achieving a BCVA ≥20/40 was higher in eyes with intact external limiting membrane and ellipsoid zone. Additional dexamethasone implant (DEXi) was injected in 14 eyes (28.57%). The treatment burden of 2.45 ± 1.35 DEXi/year was decreased to 0.57 ± 0.60 DEXi/year after FAc implantation (p=0.001). CONCLUSION: FAc implant improved the BCVA and reduced the CRT in eyes with chronic PCME after vitrectomy. The IOP rise could be anticipated by the previous response to corticosteroids. FAc implant in eyes with chronic PCME also allowed reducing the treatment burden.
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PURPOSE: To evaluate the safety and efficacy of the fluocinolone acetonide implant (FAi, Iluvien® Horus pharma, Nice, France) in non-infectious uveitic macular edema (UME) and to approach the predictive factors of treatment response. METHODS: This retrospective, multicenter real-life study included patients with chronic non-infectious UME who received intravitreal FAi after at least two dexamethasone implants (DEXi). RESULTS: Twenty-six eyes from 22 patients (73.1% of females) were included. The mean age was 60.4 ± 16 years. The mean follow-up was 11.4 ± 2 months. The mean baseline best-corrected visual acuity (BCVA) was 0.43 ± 0.36 LogMAR, improving significantly after 1, 3, 6 and 12 months (all p < 0.05 vs. baseline). The mean baseline central macular thickness (CMT) was 429 ± 110 µm, improving significantly after 1, 3, 6 and 12 months (all p < 0.05 vs. baseline). Five eyes (19.2%) developed ocular hypertension during the follow-up, requiring initiation or strengthening of intraocular pressure lowering medication. The majority of eyes (77%) did not require any rescue DEXi during the available 12-month follow-up. The resolution of UME after DEXi seemed to predict the anatomical response after FAi. The baseline presence of a disorganization of the inner retinal layers (DRIL) and hyperreflective foci (HRF) were both associated with a higher likelihood of requiring rescue DEXi injections. CONCLUSION: FAi implantation led to a significant BCVA and CMT improvement with a good safety profile over the 12-month follow-up. Predictive factors of treatment outcomes seem to include the anatomical response to DEXi and the presence of DRIL and HRF at baseline.
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INTRODUCTION: The aim of this study was to assess the efficacy and safety of fluocinolone acetonide implant (FAci) injected 1 month after the last dexamethasone intravitreal implant (DEXi) in chronic diabetic macular oedema (DME) patients. METHODS: Retrospective multicentric study conducted in pseudophakic patients with chronic DME frequently treated with dexamethasone intravitreal implant (DEXi; time to DME recurrence ≤ 6 months), receiving FAci 1 month after the last DEXi, with at least a 6-month follow-up. Best-corrected visual acuity (BCVA), central macular thickness (CMT) on optical coherence tomography, intraocular pressure (IOP) and additional treatments were assessed on the day of FAci injection (M0), 1 (M1) and 3 months (M3) later and then every 3 months. RESULTS: A total of 41 eyes from 34 patients were included. At M0, patients' mean age was 68.7 ± 9.8 years, the mean DME duration was 63.9 ± 22.9 months, the mean interval between two DEXi was 14.2 ± 3.3 weeks. M12 data were available for 71% of patients. At baseline, the mean BCVA, CMT and IOP were 63.2 ± 16.6 letters, 299.4 ± 103.3 µm, and 16.2 ± 4.5 mmHg, respectively, and remained stable during the follow-up. At M12, 14% of patients required additional intravitreal treatments. CONCLUSION: In pseudophakic patients with chronic DME showing good response to DEXi but requiring repeated injections every < 6 months, switching to FAci 1 month after the last DEXi was effective and safe. Further prospective randomized controlled studies are needed to confirm these findings, and to determine the best interval between the last DEXi and the first FAci.
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INTRODUCTION: Population-based studies show a significant increase in the prevalence of visual impairment in older patients. However, older patients and patients with lower Mini-Mental State Examination (MMSE) scores have few ophthalmological assessments. The main objective of our study was to evaluate the feasibility of tele-ophthalmological screening for ophthalmological diseases in older patients referred for cognitive assessment. METHODS: This monocentric prospective study included patients referred to a memory clinic for cognitive assessment. All patients underwent a geriatric assessment comprising a cognitive assessment associated with tele-ophthalmological screening undertaken by an orthoptist, including undilated retinal photography. The retinal photographs were subsequently sent to an ophthalmologist. We identified patients who were not eligible for ophthalmological assessment, for patients that had to come back due to poor-quality retinal photographs and finally for detected eye diseases. The association between the geriatric variable and newly detected eye diseases was analysed in univariable and multivariable analyses. RESULTS: The mean age of the 298 patients included was 83.5 years ± 5.65; 29.5% were male. The mean MMSE score was 20.8 ± 5.2; 66.3% of patients had a diagnosis of dementia. Eighteen patients (6.0%) were not eligible for ophthalmological examination and 13 patients (4.6%) were asked to come back owing to poor-quality retinal photographs. Forty-one patients (13.7%) had a newly detected eye disease. In multivariable analysis, patients with a lower MMSE had significantly more newly identified eye diseases. DISCUSSION: The tele-ophthalmological screening method identified unknown ophthalmological diseases requiring specialised management in this older population with cognitive complaints.
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Oftalmopatias , Oftalmologia , Idoso , Idoso de 80 Anos ou mais , Cognição , Oftalmopatias/diagnóstico , Humanos , Masculino , Programas de Rastreamento , Estudos ProspectivosRESUMO
PURPOSE: To identify spectral-domain optical coherence tomography (SD-OCT) predictive morphological features for the outcome of Ranibizumab therapy for neovascular age-related macular degeneration (AMD). METHODS: This is a retrospective multicentric study that involved 64 eyes with naïve AMD. Patients who received three monthly intravitreal injections of Ranibizumab were stratified into (1) "responders" [≥ 5 letters gain on Early Treatment Diabetic Retinopathy Study (ETDRS) scale] and (2) "nonresponders" (< 5 letters gain). Best-corrected visual acuity (BCVA) and SD-OCT morphological features were compared at baseline and one month after three consecutive injections of Ranibizumab. Univariate and multivariate analyses were carried out to correlate these morphological features with the change in BCVA. RESULTS: Among the 64 patients enrolled, 40 (62.5%) were "responders" and 24 (37.5%) "nonresponders". Age, sex, and BCVA were comparable between both groups. A multivariate correlational analysis found that subfoveal choroidal thickness (SFCT) and the presence of pigment epithelial detachment (PED) > 250 µm at baseline were two independent prognostic indicators of final BCVA. No other SD-OCT morphological studied features seem to affect final BCVA after Ranibizumab treatment. CONCLUSION: SFCT and the presence of PED > 250 µm are two significant biomarkers that may predict improvement after Ranibizumab therapy for AMD. These markers may guide ophthalmologists' treatment decision under financial constraints and limited time.
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Inibidores da Angiogênese/uso terapêutico , Ranibizumab/uso terapêutico , Tomografia de Coerência Óptica , Degeneração Macular Exsudativa/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados , Feminino , França , Humanos , Injeções Intravítreas , Masculino , Estudos Retrospectivos , Resultado do Tratamento , Acuidade Visual , Degeneração Macular Exsudativa/diagnóstico por imagemRESUMO
BACKGROUND: Emergence of viral variants that escape CTL control is a major hurdle in HIV vaccination unless such variants affect gene regions that are essential for virus replication. Vaccine-induced multispecific CTL could also be able to control viral variants replication. To explore these possibilities, we extensively characterized CTL responses following vaccination with an epitope-based lipopeptide vaccine and challenge with pathogenic SIVmac251. The viral sequences corresponding to the epitopes present in the vaccine as well as the viral loads were then determined in every macaque following SIV inoculation. RESULTS: In most cases, the emergence of several viral variants or mutants within vaccine CTL epitopes after SIV challenge resulted in increased viral loads except for a single macaque, which showed a single escape viral variant within its 6 vaccine-induced CTL epitopes. CONCLUSION: These findings provide a better understanding of the evolution of CD8+ epitope variations after vaccination-induced CTL expansion and might provide new insight for the development of an effective HIV vaccine.
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Produtos do Gene nef/imunologia , Macaca mulatta/imunologia , Macaca mulatta/virologia , Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/genética , Animais , Produtos do Gene nef/genética , Lipoproteínas/genética , Lipoproteínas/imunologia , Mutação/genética , RNA Viral/sangue , Vacinas contra a SAIDS/administração & dosagem , Vírus da Imunodeficiência Símia/imunologia , Vírus da Imunodeficiência Símia/patogenicidade , Linfócitos T Citotóxicos/fisiologia , Carga Viral , ViremiaRESUMO
Numerous clinical and experimental observations have shown that cellular immunity, in particular CD8+ T-lymphocytes, plays an important role in the control of HIV infection. We have focused on a lipopeptide vaccination strategy that has been shown to induce polyepitopic T-cell responses in both animals and humans, in order to deliver simian immunodeficiency virus (SIV) antigens to rhesus macaques. Given the relevance of antigen administration route in the development of an effective cellular immune response, this study was designed to assess SIV lipopeptide immunizations administered either by the intradermal (ID) or the intramuscular (IM) routes in their ability to elicit GAG and NEF multispecific T-lymphocytes in the rhesus macaque. Antigen specific T-cell responses were observed between 7 and 11 weeks following vaccination in both groups. Macaques immunized by the IM route yielded antigen-specific IFN-gamma secreting lymphocytes in response to no more than two pools of peptides derived from SIV-NEF. In contrast, among the four ID-immunized macaques, two presented multi-specific T-cell responses to as many as four pools of SIV-NEF and/or GAG peptides. Responses persisted 16 weeks following the vaccination protocol in one of the ID-vaccinated macaques. The induction of such responses is of great clinical relevance in the development of an effective HIV vaccine. Given the crucial role of CD8+ T-lymphocytes in HIV/SIV containment, vaccination through the intradermal route should merit high consideration in the development of an AIDS vaccine.
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Vacinas contra a SAIDS/administração & dosagem , Vírus da Imunodeficiência Símia/imunologia , Linfócitos T/imunologia , Sequência de Aminoácidos , Animais , Antígenos Virais/genética , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Epitopos/genética , Técnicas In Vitro , Injeções Intradérmicas , Lipoproteínas/administração & dosagem , Lipoproteínas/genética , Lipoproteínas/imunologia , Ativação Linfocitária , Macaca mulatta , Masculino , Dados de Sequência Molecular , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/imunologia , Proteínas Virais/administração & dosagem , Proteínas Virais/genética , Proteínas Virais/imunologiaRESUMO
Insulin degrading enzyme (IDE) is a zinc metalloprotease that degrades small amyloid peptides such as amyloid-â and insulin. So far the dearth of IDE-specific pharmacological inhibitors impacts the understanding of its role in the physiopathology of Alzheimer's disease, amyloid-â clearance, and its validation as a potential therapeutic target. Hit 1 was previously discovered by high-throughput screening. Here we describe the structure-activity study, that required the synthesis of 48 analogues. We found that while the carboxylic acid, the imidazole and the tertiary amine were critical for activity, the methyl ester was successfully optimized to an amide or a 1,2,4-oxadiazole. Along with improving their activity, compounds were optimized for solubility, lipophilicity and stability in plasma and microsomes. The docking or co-crystallization of some compounds at the exosite or the catalytic site of IDE provided the structural basis for IDE inhibition. The pharmacokinetic properties of best compounds 44 and 46 were measured in vivo. As a result, 44 (BDM43079) and its methyl ester precursor 48 (BDM43124) are useful chemical probes for the exploration of IDE's role.
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Carbamatos/farmacologia , Ácidos Carboxílicos/química , Inibidores Enzimáticos/farmacologia , Imidazóis/química , Insulisina/antagonistas & inibidores , Insulisina/metabolismo , Oxidiazóis/farmacologia , Carbamatos/síntese química , Carbamatos/química , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Modelos Moleculares , Estrutura Molecular , Oxidiazóis/síntese química , Oxidiazóis/química , Relação Estrutura-AtividadeRESUMO
We investigated the relationships between class II human leukocyte antigens (HLA) and the antibody response to Plasmodium falciparum p126 protein and to its amino-terminal portion (Nt47) in 2 malaria-endemic villages in Brazil, Colina and Ribeirinha. All people from the endemic areas had anti-p126 antibodies, and the frequencies of anti-Nt47 antibodies were similar in both communities (66% for Colina and 75% for Ribeirinha). Typing of HLA showed that Colina and Ribeirinha groups had no significant differences in HLA antigen frequencies. However, in both groups, significant associations between positive response to anti-Nt47 and presence of HLA-DR4, as well as between absence of response and presence of HLA-DR15, were observed. The predominance of positive responses to Nt47 among HLA-DR4 people was independent of the presence of any particular allele. There was no evidence for association between HLA-DQB1 alleles and antibody response to Nt47. Thus, naturally exposed people with different HLA class II antigens seem to respond differently to Nt47, indicating that the choice of relevant peptide sequences may have important consequences for subunit vaccine development.
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Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Antígenos HLA-D/imunologia , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia , Adulto , Alelos , Animais , Formação de Anticorpos , Brasil , Feminino , Genes MHC da Classe II , Geografia , Antígenos HLA-DR/análise , Subtipos Sorológicos de HLA-DR , Antígeno HLA-DR4/análise , Teste de Histocompatibilidade , Humanos , Malária Falciparum/imunologia , MasculinoRESUMO
A practical preparation of onion vesicles targeted to dendritic cells involves the grafting of mannose-mimetic clusters, bearing a hydrazino group, onto the surface of onion vesicles containing an aldehyde functionalized lipid.
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Células Dendríticas/metabolismo , Lectinas Tipo C/metabolismo , Lipossomos/farmacocinética , Lectinas de Ligação a Manose/metabolismo , Receptores de Superfície Celular/metabolismo , Técnicas de Química Combinatória , Células Dendríticas/química , Sistemas de Liberação de Medicamentos/métodos , Humanos , Ligantes , Lipossomos/síntese química , Lipossomos/uso terapêutico , Receptor de Manose , Microscopia ConfocalRESUMO
Over the last decade, there has been a large effort to target aggrecanases, which are responsible for the degradation of the aggrecan in the extracellular matrix of joints, in order to hopefully lead to new treatments for osteoarthritis. Only a few inhibitors have been effective in explants or rodent models and thus only a few have reached the clinic, none of which have proven to be effective. In this article, a survey of chemical series is described, covering historical and recent inhibitors and highlighting how some of their problems were resolved, with a critical overview of the challenges encountered. A large effort should be undertaken in designing smaller compounds with higher residence times, defining new interaction sites on the aggrecanases and exploiting target flexibility.
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Endopeptidases/metabolismo , Osteoartrite/tratamento farmacológico , Inibidores de Proteases/farmacologia , Inibidores de Proteases/uso terapêutico , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Osteoartrite/enzimologia , Osteoartrite/metabolismo , Inibidores de Proteases/química , Relação Estrutura-AtividadeRESUMO
Purpose. To report favorable outcome of a case of acute posterior multifocal placoid pigment epitheliopathy (APMPPE) associated with cerebral vasculitis after treatment with immunosuppressive therapy by mitoxantrone. Design. Single case report. Method. A 22-year-old man presented with acute isolated bilateral loss of vision revealing APMPPE. Corticosteroid therapy was initiated and visual acuity gradually improved. Seventeen days later, visual function deteriorated again, associated with flu-like syndrome and severe headaches. A relapse of APMPPE was diagnosed, complicated with lymphocytic meningitis and cerebral ischemia. Intravenous therapy with mitoxantrone was performed in combination with methylprednisolone. Results. Headaches disappeared in a few days whereas visual acuity gradually improved and stabilized at 20/40 in the right eye and 20/32 in the left eye. No adverse event was observed. Clinical improvement was confirmed by magnetic resonance imaging. Conclusion. Cerebral vasculitis is the most severe complication of the extraocular manifestations of APMPEE. This diagnosis should be evoked when severe headaches or behavior disorder are associated with APMPEE.
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alpha-Melanocyte-stimulating hormone (alpha-MSH) is an endogeneous linear tridecapeptide with potential application for the modulation of skin tanning. To evaluate the interest of introducing a lipid moiety onto this peptide, we developed an efficient chemoselective parallel method to prepare a large series of analogues of alpha-melanocortin with high purity, varying the nature or the relative position of the lipid moiety. Two sets of building blocks containing lipidic alpha-oxo-aldehydes or alpha-hydrazinoacetyl peptides were combined to obtain a 102-membered library of amphiphilic alpha-MSH analogues. This library was pharmacologically tested at 1 x 10(-7) M for the ability to induce AMPc production in M4Be melanoma cell line after stimulation of the human melanocortin MC1 receptor. Among theses lipopeptides, 84 compounds exhibited an AMPc induction higher than Melitane, a patented alpha-MSH agonist. These results provide strong evidence of the interest of introduction of a lipid tail for the pharmacomodulation of bioactive peptides.
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Hidrazonas/química , Lipoproteínas/síntese química , Peptídeos/síntese química , alfa-MSH/química , Aldeídos/síntese química , Sequência de Aminoácidos , Linhagem Celular Tumoral/efeitos dos fármacos , Cromatografia Líquida , Eletroforese , Humanos , Lipoproteínas/farmacologia , Espectrometria de Massas , Melanoma/metabolismo , Melanoma/patologia , Dados de Sequência Molecular , Biblioteca de Peptídeos , Peptídeos/farmacologia , Receptor Tipo 1 de Melanocortina/metabolismo , alfa-MSH/farmacologiaRESUMO
The selective delivery of antigens to professional antigen-presenting cells represents a promising approach to improve vaccine efficacy. Addition of a glycoamphiphile to a lipopeptide, whose interest for vaccination is now well-established, greatly favors its solubilization in aqueous solutions through the formation of mixed vesicles. Flow cytometry experiments indicate that this formulation does not diminish the uptake of the lipopeptide by the dendritic cells (DCs). These preliminary results suggest a possible straightforward, noncovalent targeting of cocktail-lipopeptide vaccines to the DCs via carbohydrate receptor-mediated endocytosis.
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Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Glucose/química , Glucose/metabolismo , Lipoproteínas/química , Lipoproteínas/metabolismo , Peptídeos/metabolismo , Transporte Biológico , Células Cultivadas , Endocitose , Citometria de Fluxo , Humanos , Estrutura Molecular , Peptídeos/química , Rodaminas , Solubilidade , VacinasRESUMO
Synthetic peptidoliposomes have been designed and prepared according to a chemoselective ligation. Two aldehyde-functionalized lipidic anchors were synthesized and incorporated into the lipidic bilayers of unilamellar liposomes during their preparation. Complementary hydrazino acetyl peptides were synthesized on the solid phase using N,N',N'-tri(tert-butyloxycarbonyl)-hydrazino acetic acid and further coupled to the aldehyde groups displayed at the surface of the vesicles. Coupling yields were measured by amino acid hydrolysis following total acid hydrolysis. The ligation methodology proved superior to the simple insertion of lipopeptides, which was performed for comparison in terms of yields, implementation, and reproducibility. To check whether the grafted-peptides were accessible and functional, cytoplasmic sequences of LAMP protein (lysosomal associated membrane protein), which is involved in intracellular membrane trafficking, have been selected. Using this model, we demonstrated in vitro the specific interaction of the synthetic LAMP-peptidoliposomes with the cytoplasmic adaptor protein AP-3, a result that contributes to the understanding of protein sorting in cells. Thus, these results clearly indicate the usefulness of such peptidoliposomes, easily prepared by hydrazone chemoselective ligation, as a tool for biological investigation.
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Hidrazonas/química , Lipossomos/síntese química , Sondas Moleculares/síntese química , Peptídeos/química , Complexo 3 de Proteínas Adaptadoras , Subunidades delta do Complexo de Proteínas Adaptadoras , Antígenos CD , Técnicas de Química Combinatória , Proteínas de Membrana Lisossomal , Peptídeos/síntese química , Transporte Proteico , Fatores de Transcrição/metabolismoRESUMO
The ability of single-chain lipopeptides to gain access to cellular compartments other than those related to degradation/recycling was first deduced from their capacity to deliver peptide antigens into MHC-class I loading mechanisms. The ability of lipopeptides to escape complete endosome degradation was further illustrated by the selective inhibition of different protein kinase C isoenzymes and, more recently, the presentation of agonistic activity towards the interferon gamma receptor. Taken together, several independent results indicate that modification of a peptide by a single lipid chain confers upon it intracellular trafficking properties that can be used to deliver functional cargo peptides into living cells; the endoplasmic reticulum, cytosolic protease activity, sites of kinase activity, or even the signalling pathway associated with cytokine stimulation, all appear accessible to peptide modified by a single lipidic moiety. In this context, the interferon gamma receptor can be considered as a very discriminative pharmacological model, useful for the comparative evaluation of the cellular delivery of lipopeptides, as it allows the unambiguous tracking of their intact delivery into a wide range of cellular compartments. This model is now being used to probe the influence of the nature of the lipid moiety on the trafficking properties of lipopeptides.