[Utility of optic coherence tomography (OCT) in the follow-up of idiopathic intracranial hypertension in childhood]. / Utilidad del tomógrafo de coherencia óptica (OCT) en el seguimiento de la hipertensión intracraneal idiopática en la infancia.

PURPOSE: To show the utility of optic coherence tomography (OCT) in the follow up of the idiopathic intracranial hypertension (IIH) in childhood. METHODS: Three girls, aged between 4 and 11 years, were diagnosed and subsequently followed with the help of OCT for an episode of idiopathic intracranial hypertension. All of them had presented with non-specific symptoms such as visual disturbance, headache, stomach ache, and in one case diplopia and torticolis. Brain imaging studies were normal, however lumbar puncture found an elevated intracranial pressure. Visual fields were tested using Octopus automated perimetry and the optic nerve fiber layer (ONF) was measured by OCT at each of the attendances. RESULTS: The visual acuity was normal in all cases, but two girls had evidence of an abducens nerve palsy. Fundus biomicroscopy revealed marked papilledema. The thickness of the ONF was increased 2-3 times over normally expected levels. The follow up and the treatment with prednisone and azetazolamide was monitored by OCT, with a good outcome and return of the ONF levels to normal. In one case, however, a recurrence was detected after three months without treatment. CONCLUSION: IIH in childhood is an uncommon condition, often with a different presentation from what is seen in teenagers and adults. OCT is a useful technique helping in both the diagnosis and the follow-up of this disorder in children (Arch Soc Esp Oftalmol 2006; 81: 383-390).

Utilidad del tomógrafo de coherencia óptica (OCT) en el seguimiento de la hipertensión intracraneal idiopática en la infancia / Utility of optic coherence tomography (OCT) in the follow-up of idiopathic intracranial hypertension in childhood

Objetivo: Mostrar la utilidad de la tomografía decoherencia óptica (OCT) en el seguimiento de lahipertensión intracraneal idiopática (HII) en la edadpediátrica.Métodos: Se ha realizado el diagnóstico y posteriorseguimiento, del episodio agudo de HII en tresniñas con edades entre 4 y 11 años. Todas acudieroncon síntomas inespecíficos: Alteraciones visuales,cefalea, abdominalgia, visión doble y tortícolis.Los estudios de neuroimagen fueron normales. Trasla punción lumbar, la presión intracraneal estabaelevada. Se realizó campo visual (CV) medianteperímetro Octopus y medida de la capa de fibrasnerviosas (CFN) con OCT en todas las revisiones.Resultados: La agudeza visual fue normal en todasellas, con paresia de VI par en dos casos. El estudiode fondo de ojo reveló siempre un gran edema depapila. La medida inicial de la CFN con OCT sehalló elevada, duplicando o triplicando los valoresnormales. El seguimiento y tratamiento con prednisona y acetazolamida vía oral se realizó de acuerdoa las medidas del OCT. La evolución fue buena conprogresiva normalización de los valores de grosoren el OCT. Si bien en un caso, tras 3 meses sin tratamiento,se detectó mediante OCT una recurrenciaasintomática.Conclusiones: La HII en edad pediátrica es unaentidad poco frecuente y diferente de la afectacióntípica del adolescente y el adulto. El OCT es unatécnica objetiva y reproducible que puede ayudar acompletar el diagnóstico y, sobre todo, el posteriorseguimiento clínico y terapéutico de estos cuadrosen niños

Purpose: To show the utility of optic coherence ;;tomography (OCT) in the follow up of the idiopathic ;;intracranial hypertension (IIH) in childhood. ;;Methods: Three girls, aged between 4 and 11 ;;years, were diagnosed and subsequently followed ;;with the help of OCT for an episode of idiopathic ;;intracranial hypertension. All of them had presented ;;with non-specific symptoms such as visual disturbance, ;;headache, stomach ache, and in one case ;;diplopia and torticolis. Brain imaging studies were ;;normal, however lumbar puncture found an elevated ;;intracranial pressure. Visual fields were tested ;;using Octopus automated perimetry and the optic ;;nerve fiber layer (ONF) was measured by OCT at ;;each of the attendances. ;;Results: The visual acuity was normal in all cases, ;;but two girls had evidence of an abducens nerve ;;palsy. Fundus biomicroscopy revealed marked ;;papilledema. The thickness of the ONF was increased ;;2-3 times over normally expected levels. The follow up and the treatment with prednisone and azetazolamide ;;was monitored by OCT, with a good outcome ;;and return of the ONF levels to normal. In one ;;case, however, a recurrence was detected after three ;;months without treatment. ;;Conclusion: IIH in childhood is an uncommon ;;condition, often with a different presentation from ;;what is seen in teenagers and adults. OCT is a useful ;;technique helping in both the diagnosis and the ;;follow-up of this disorder in children

Ultrastructural evidence of mucus in human conjunctival epithelial cultures.

PURPOSE: To demonstrate by ultrastructural techniques that human conjunctival epithelium cells in vitro can produce mucin-like secretion. METHODS: Primary cultures of human conjunctival epithelial cells were grown in different culture media. Cultures were allowed to grow and were processed after 5 days and 1, 2, 3, 4, or 5 weeks for transmission and scanning electron microscopy, according to the method of Nichols et al. modified in our laboratory. RESULTS: Marked differences were seen between primary cultures grown with or without hydrocortisone. A thick tannic acid-stained layer was observed when hydrocortisone was present in the culture medium; however, that layer was virtually absent in cultures grown with hydrocortisone-free media. Scanning electron microscopy revealed a dense deposit showing a network-like structure. Moreover, the age of the cultures clearly influenced the thickness of the tannic acid-stained deposit, which thickened as the cultures aged. CONCLUSIONS: These results strongly suggest that the layer growing in the presence of hydrocortisone is mucus. The fact that this material became more abundant as the cultures aged indicates that mucus is actively produced and secreted by conjunctival epithelial cells in vitro. This study might contribute to the knowledge of mucus-deficient pathologies of the ocular surface.

Proline-138 is essential for the assembly of hepatitis B virus core protein.

In small RNA viruses, arm-like segments located at the N or C termini have been suggested as mediators in the assembly of the capsid proteins. In many cases the arms of several subunits converge at a common point (the symmetry axis). Recent advances in studies of the hepatitis B virus (HBV) core protein attest the convergence of the segments preceding the protamine region, around the symmetry axis, where five or six HBc protein subunits converge. We report a mutation study of the region that we have suggested forms an arm-like structure, which reveals that a single mutation, Pro-138 --> Gly, prevents the full-length HBV core protein self-assembling into particles.

Folding and assembly of hepatitis B virus core protein: a new model proposal.

Hepatitis B core antigen has been intensively studied. Recently, cryoelectron microscopy studies have determined the structure of human and duck hepatitis B virus nucleocapsids at low resolution. Both viruses assemble into core particles of two sizes with icosahedral dimer-clustered T = 3 and T = 4 symmetries. Both capsids present tightly clustered dimers composed of a shell and a protruding domain. The present work introduces a model for HBc folding, dimer formation, and assembly. The model is based in multiple alignments of HBc sequences from 20 mammalian and avian isolates and secondary structure predictions. The 54% alpha-helical conformation predicted is in good agreement with CD results reporting 53-71% content of alpha-helices. Despite the sequence divergence of mammalian and avian proteins, the secondary structure prediction of both shows a high degree of coincidence, according to the multiple sequence alignment. The proposed fold of HBc monomers is built from five alpha-helices. In dimers, pairs of two of those helices conform the protruding domain. The model also suggests the convergence of the region preceding the protamine domain around the sixfold symmetry axes. The model gives answers to most of the standing questions concerning the nucleocapsid assembly and antigenic behavior of HBc protein.

A lipoamide dehydrogenase from Neisseria meningitidis has a lipoyl domain.

A protein of molecular weight of 64 kDa (p64k) found in the outer membrane of Neisseria meningitidis shows a high degree of homology with both the lipoyl domain of the acetyltransferase and the entire sequence of the lipoamide dehydrogenase, the E2 and E3 components of the dehydrogenase multienzyme complexes, respectively. The alignment of the p64k with lipoyl domains and lipoamide dehydrogenases from different species is presented. The possible implications of this protein in binding protein-dependent transport are discussed. This is the first lipoamide dehydrogenase reported to have a lipoyl domain.

High level expression of the B. microplus Bm86 antigen in the yeast Pichia pastoris forming highly immunogenic particles for cattle.

Recently, a gene coding for the Bm86 tick gut glycoprotein was cloned, expressed in Escherichia coli and shown to induce an immunological response in cattle to damage ticks engorging on these animals (Rand et al., 1989). We report here the increased expression of the Bm86 antigen from the cattle tick Boophilus microplus in the methylotrophic yeast Pichia pastoris. The recombinant protein was obtained with a purity higher than 95% by a procedure with a high yield. The conducted biochemical studies demonstrated the antigen to be glycosylated and found to form particles of around 17 to 45 nm in diameter with enhanced immunogenic properties. Ticks engorging on vaccinated cattle were significantly damaged as a result of the immune response against the recombinant antigen. This system permits the obtainment in a high yield of the tick Bm86 antigen, in a glycosylated and particulated form.

Prediction of protein folding pathways.

Recent 1H nuclear magnetic resonance (n.m.r.) hydrogen exchange experiments on five different proteins have delineated the secondary structures formed in trapped, partially folded intermediates. The early forming structural elements are identifiable through a technique described in this work to predict folding pathways. The method assumes that the sequential selection of structural fragments such as alpha-helices and beta-strands involved in the folding process is founded upon the maximal burial of solvent accessible surface from both the formation of internal structure and substructure association. The substructural elements were defined objectively by major changes in main-chain direction. The predicted folding pathways are in complete correspondence with the n.m.r. results in that the formed structural fragments found in the folding intermediates are those predicted earliest in the pathways. The technique was also applied to proteins of known tertiary structure and with fold similar to one of the five proteins examined by 1H n.m.r. The pathways for these structures also showed general consistency with the n.m.r. observations, suggesting conservation of a secondary structural framework or molten globule about which folding nucleates and proceeds.