Neuropatía óptica compresiva. No todo lo que progresa es glaucoma / Compressive optic neuropathy. Not everything that progresses is glaucoma

Se presentan 3 casos clínicos de neuropatía óptica compresiva secundaria a meningiomas de diferente localización, diagnosticados inicialmente de glaucoma de tensión normal. Todas las pacientes eran mujeres de edad media, con excavación papilar, así como defectos en el campo visual asimétricos, rápidamente progresivos y deterioro de la agudeza visual, a pesar de presentar cifras de presión intraocular correctamente controladas con tratamiento hipotensor tópico. Debido a la evolución atípica de la enfermedad glaucomatosa, y sospechando una lesión compresiva del nervio óptico, se realizaron pruebas de neuroimagen, con las que se llegó al diagnóstico correcto. En casos de glaucoma de tensión normal hay que tener en cuenta como diagnóstico diferencial la neuropatía óptica compresiva. Diferenciar ambas afecciones constituye un reto diagnóstico que se debe sospechar ante la disminución atípica de la agudeza visual y deterioro de las pruebas, tanto funcionales como estructurales, de manera asimétrica y pese a las cifras de presión intraocular normales (AU)

Three clinical cases are presented of compressive optic neuropathy secondary to meningiomas of different locations, initially diagnosed with normal tension glaucoma (NTG). All patients were middle-aged women, with optic disc excavation, as well as asymmetric, rapidly progressive defects in the visual field (VF), and deterioration of the visual acuity (VA), despite presenting with intraocular pressure (IOP) correctly controlled with topical hypotensive therapy. Due to the atypical progression of the glaucoma disease, and suspecting a compressive lesion of the optic nerve, neuroimaging tests were performed, with which the correct diagnosis was reached. In cases of NTG, it is necessary to take into account compressive optic neuropathy as a differential diagnosis. Differentiating both pathologies is a diagnostic challenge that should be suspected due to the atypical decrease of the VA and deterioration of both functional and structural tests, and asymmetrically, despite the normal IOP (AU)

Compressive optic neuropathy. Not everything that progresses is glaucoma. / Neuropatía óptica compresiva. No todo lo que progresa es glaucoma.

Three clinical cases are presented of compressive optic neuropathy secondary to meningiomas of different locations, initially diagnosed with normal tension glaucoma (NTG). All patients were middle-aged women, with optic disc excavation, as well as asymmetric, rapidly progressive defects in the visual field (VF), and deterioration of the visual acuity (VA), despite presenting with intraocular pressure (IOP) correctly controlled with topical hypotensive therapy. Due to the atypical progression of the glaucoma disease, and suspecting a compressive lesion of the optic nerve, neuroimaging tests were performed, with which the correct diagnosis was reached. In cases of NTG, it is necessary to take into account compressive optic neuropathy as a differential diagnosis. Differentiating both pathologies is a diagnostic challenge that should be suspected due to the atypical decrease of the VA and deterioration of both functional and structural tests, and asymmetrically, despite the normal IOP.

Prevalence of human papillomavirus types in North and Central regions of Mexico.

Human papillomavirus (HPV) is a DNA virus linked to mucosal and cutaneous carcinogenesis. More than 200 different HPV types exist. We carried out a transversal study to investigate the prevalence of HPV types in two regions of Mexico. A total of 724 genital and non-genital samples from women (F) and men (M) were studied; 241 (33%) from North-Eastern (NE) and 483 (66%) from South-Central (SC) Mexico. The overall prevalence was 87%. In genital lesions from females, the NE group showed a prevalence of HPV types 16 (37%), 6 (13%), 59 (6%), 11, 18 and 66 (5.4% each); and the SC group showed types 6 (17%), 16 (15%), 11 (14.5%), 18 (12%) and 53 (6%). In the genital lesions from males, NE group showed types 16 (38%), 6 (21%), 11 (13%) and 59 plus 31 (7.5%) and the SC group showed types 6 (25%), 11 (22%), 18 (17%) and 16 (11.5%). When the two regions were compared, a higher prevalence of low-risk HPV 6 and 11 was found in the SC region and of high-risk HPV 59, 31 and 66 (the latter can also be present in benign lesions) in the NE region. Our findings complement efforts to understand HPV demographics as a prerequisite to guide and assess the impact of preventive interventions.

Trypanosoma cruzi heparin-binding proteins present a flagellar membrane localization and serine proteinase activity.

Heparin-binding proteins (HBPs) play a key role in Trypanosoma cruzi-host cell interactions. HBPs recognize heparan sulfate (HS) at the host cell surface and are able to induce the cytoadherence and invasion of this parasite. Herein, we analysed the biochemical properties of the HBPs and also evaluated the expression and subcellular localization of HBPs in T. cruzi trypomastigotes. A flow cytometry analysis revealed that HBPs are highly expressed at the surface of trypomastigotes, and their peculiar localization mainly at the flagellar membrane, which is known as an important signalling domain, may enhance their binding to HS and elicit the parasite invasion. The plasmon surface resonance results demonstrated the stability of HBPs and their affinity to HS and heparin. Additionally, gelatinolytic activities of 70 kDa, 65·8 kDa and 59 kDa HBPs over a broad pH range (5·5-8·0) were revealed using a zymography assay. These proteolytic activities were sensitive to serine proteinase inhibitors, such as aprotinin and phenylmethylsulfonyl fluoride, suggesting that HBPs have the properties of trypsin-like proteinases.

Trypanosoma cruzi heparin-binding proteins mediate the adherence of epimastigotes to the midgut epithelial cells of Rhodnius prolixus.

Heparin-binding proteins (HBPs) have been demonstrated in both infective forms of Trypanosoma cruzi and are involved in the recognition and invasion of mammalian cells. In this study, we evaluated the potential biological function of these proteins during the parasite-vector interaction. HBPs, with molecular masses of 65·8 kDa and 59 kDa, were isolated from epimastigotes by heparin affinity chromatography and identified by biotin-conjugated sulfated glycosaminoglycans (GAGs). Surface plasmon resonance biosensor analysis demonstrated stable receptor-ligand binding based on the association and dissociation values. Pre-incubation of epimastigotes with GAGs led to an inhibition of parasite binding to immobilized heparin. Competition assays were performed to evaluate the role of the HBP-GAG interaction in the recognition and adhesion of epimastigotes to midgut epithelial cells of Rhodnius prolixus. Epithelial cells pre-incubated with HBPs yielded a 3·8-fold inhibition in the adhesion of epimastigotes. The pre-treatment of epimastigotes with heparin, heparan sulfate and chondroitin sulfate significantly inhibited parasite adhesion to midgut epithelial cells, which was confirmed by scanning electron microscopy. We provide evidence that heparin-binding proteins are found on the surface of T. cruzi epimastigotes and demonstrate their key role in the recognition of sulfated GAGs on the surface of midgut epithelial cells of the insect vector.

A mechanobiological model of epiphysis structures formation.

Developing bone consists of epiphysis, metaphysis and diaphysis. The secondary ossification centre (SOC) appears and grows within the epiphysis, involving two histological stages. Firstly, cartilage canals appear; they carry hypertrophy factors towards the central area of the epiphysis. Canal growth and expansion is modulated by stress on the epiphysis. Secondly, the diffusion of hypertrophy factors causes SOC growth. Hypertrophy is regulated by biological and mechanical factors present within the epiphysis. The finite element method has been used for solving a coupled system of differential equations for modelling these histological stages of epiphyseal development. Cartilage canal spatial-temporal growth patterns were obtained as well as the SOC formation pattern. This model qualitatively agreed with experimental results reported by other authors.

Familial clustering of multiple sclerosis in a Dutch genetic isolate.

Multiple sclerosis (MS) is a complex disease with a substantial, yet poorly identified, genetic influence. We estimated the pattern of familial aggregation of MS in a recent genetically isolated population in The Netherlands. Forty-eight MS patients were identified. Their relationship was evaluated by tracing extended pedigrees, making use of municipal and church records. Of the 48 MS patients, 24 could be linked to a common ancestor in 14 generations. However, multiple relationships exist between patients and, to take these into account, we calculated inbreeding and kinship coefficients. We found that MS patients from the isolate were significantly more often related to each other and significantly more often inbred than a non-MS control group, drawn from the same isolate. There was no clustering of Type 1 diabetes and autoimmune thyroid diseases in families of MS patients from this isolate. Finally, HLA typing was performed. Although there was a trend towards a higher prevalence of the HLA DRB1*15 allele in patients compared to controls, differences did not reach significance. This study suggests familial aggregation in the genetically isolated population. The high level of inbreeding makes this population valuable for finding novel genes involved in MS.

Heparin binding proteins from Leishmania (Viannia) braziliensis promastigotes.

We have examined the heparin binding proteins from Leishmania (Viannia) braziliensis promastigotes (HBP-Lb) by chromatography assays. The proposed strategy to isolate an enriched fraction of the HBP-Lb consisted of an association of the Triton X-114 method with affinity chromatography in heparin-Sepharose 4B column. SDS-PAGE analysis of the eluted proteins showed two main protein bands (65.0 and 54.5 kDa), while a single protein band was observed in native electrophoresis gel. The hemagglutination property of HBP-Lb over rabbit erythrocytes was confirmed up to 6.3+/-0.5 microg of protein mL(-1). Additionally, we have assayed the potential of HBP-Lb labeled with sulfo-NHS-LC-biotin in binding to nitrocellulose-immobilized gut proteins extracted of Lutzomyia intermedia and Lutzomyia whitmani. The results indicated a similar profile of five ligands (67.0, 62.1, 59.5, 56.0 and 47.5 kDa) in both studied Lutzomyia species. This is the first direct description of this class of protein in L. (V.) braziliensis with a suggestion of its biological activity in the interaction of Leishmania with Lutzomyia gut cells, which maybe a crucial step during this parasite's life cycle.

HLA-DQB1, -DQA1, -DRB1 linkage disequilibrium and haplotype diversity in a Mestizo population from Guadalajara, Mexico.

HLA-DQB1, -DQA1, and -DRB1 genes were typed by polymerase chain reaction with sequence-specific primer (PCR-SSP) in 159 healthy volunteers from 32 families living in Guadalajara, Mexico. Three-locus genotype data from all family members were used to infer haplotypes in 54 unrelated individuals of the sample, from which estimate of segregating haplotype frequencies and linkage disequilibrium (LD) between loci were computed. Genotype distributions were concordant with Hardy-Weinberg expectations (HWE) for all three loci, and allele distributions were similar to the ones observed in other Latin-American populations. Of the 56 distinct three-site (DQB1-DQA1-DRB1) haplotypes observed in the sample, the five most common (i.e., with frequencies of five counts or more) were: *0302-*0301-*04, *0201-*0201-*07, *0301-*0501-*14, *0402-*0401-*08, and *0501-*0101-*01. These common three-locus haplotypes also contributed to the majority of the significant two-locus linkage disequilibria of these three sites.

Formative research to inform intervention development for diabetes prevention in the Republic of the Marshall Islands.

Formative research was conducted in the Republic of the Marshall Islands to help develop a diabetes prevention intervention. Methods included in-depth interviews, semistructured interviews, and direct observation of household behaviors in urban and remote settings. Foods were classified into two main conceptual spheres: foods from the islands/Marshallese foods and imported/American foods. Diabetes (nanimij in tonal) is a highly salient illness and is believed to be caused by foods high in fat and sugar, consumption of imported/American foods, family background, and the atomic bomb testing. Physical activity and eating a traditional diet were viewed as important for preventing diabetes. The traditional belief system links a large body with health, and a thin body with illness; however, perceptions are changing with increased acculturation and education about the health risks of obesity. These findings were used to develop a diabetes prevention home visit intervention currently being implemented and evaluated in Marshallese households.

Intracellular localisation of dengue-2 RNA in mosquito cell culture using electron microscopic in situ hybridisation.

Non-isotopic in situ hybridisation was used at the electron microscope level to determine the localisation of viral RNA in dengue-2 infected mosquito cells at 14, 24, 48 and 72 h post-infection. In situ hybridisation was carried out on sections of dengue-2 infected mosquito cells using a digoxigenin-labelled DNA probe to the envelope protein gene sequence of the virus. Viral RNA was consistently localised over the rough endoplasmic reticulum and the virus-induced smooth membrane structures which form within the endoplasmic reticulum. During the later stages of infection electron-dense areas were observed to develop in close proximity to the smooth membrane structures. Electron microscopic in situ hybridisation showed that these denser areas contained both viral RNA and virus particles. Our results show that in dengue-2 infected mosquito cells the smooth membrane structures are an important site for the concentration of dengue viral RNA and its possible subsequent encapsidation into virus particles.

Ultrastructural aspects of virus replication in one fatal case and several other isolates from a dengue type 2 outbreak in Rio de Janeiro.

Dengue virus replication in mosquito cell cultures was observed by electron microscopy in one fatal and 40 classical isolates from a dengue type 2 outbreak in Rio de Janeiro and compared with the prototype New Guinea C strain. All the Brazilian isolates presented, beside the classical structured dengue virus particles, fuzzy coated virus-like particles, never observed in the referencial New Guinea C virus strain. More numerous DEN-2 virus particles, fuzzy coated virus-like particles, defective virus particles and smooth membrane structures inside the rough endoplasmic reticulum characterized the unique fatal isolate examined.

Actinomicosis pulmonar / Pulmonary actinomycosis

La actinomicosis torácica pulmonar, rara de ver en la actualidad, ha cambiado considerablemente su presentación clínica, siendo infrecuente ver los antiguos cuadros con destrucción de la pared del tórax y trayectos sinuosos de drenaje. En los últimos tres años en la literatura médica nacional hay sólo algunas publicaciones con 1 ó 2 casos. Presentamos 3 pacientes atendidos en los 2 últimos años en nuestro Servicio con forma de presentación diferente. El diagnóstico definitivo en los tres pacientes se efectuó por el estudio histopatológico de las muestras enviadas. Se analiza las características del germen, formas clínicas de presentación, dificultades diagnósticas y terapia más convenientes

Timectomía total en miastenia gravis / Total thymectomy in myasthenia gravis

Se analiza nuestra experiencia en pacientes con miastenia gravis realizadas en los últimos 10 años. Corresponde a 7 pacientes de sexo masculino y 4 femenino, con una edad media de 35 años. De acuerdo a la clasificación de Osserman, hemos intervenido 4 pacientes en etapa 2A, 5 en 2B y 2 en etapa 1. La histopatología informó: hiperplasia del timo en 8, timo involutivo en 1, grasa con restos de tejido tímico en 1, tejido graso con islotes de células linfocitarias en 1. No hubo mortalidad ni complicaciones quirúrgicas de importancia derivadas de la intervención. Sólo 2 pacientes, en etapa 2B, presentan dentro de las 24 horas del postoperatorio crisis miasténica, que tratadas en forma adecuada evolucionaron bien.