[Variability and reproducibility of 3 methods for measuring the thickness of the nerve fiber layer]. / Variabilidad interindividual y reproducibilidad de tres métodos de medida del espesor de la capa de fibras nerviosas.

OBJECTIVE: To estimate the variability and reproducibility of confocal tomography (HRT), scanning laser polarimetry (GDx) and optical coherence tomography (OCT-Cirrus) to determine the thickness of the layer of ganglion fibers. METHOD: A total of 75 normal eyes were examined twice. Inter-individual variability was analyzed after standardizing the results. The coefficient of variation was used to measure the variability between tests, and the Pearson coefficient was used to analyze the correlation between variables. RESULTS: The inter-individual variability was similar in GDx (8.9%) and OCT (11.1%), but very high in HRT (30.0%). No instrument detected significant changes with age. The coefficient of variation of the total thickness between the examinations of the same subject was significantly lower (P<.05) in GDx (1.4) than in OCT (2.0), but very high in HRT (6.4). The same was true when analyzing the upper fibers (GDx=1.8, OCT=2.9, HRT = 6.6), but not with the lower ones, where the only significant differences were observed with HRT (GDx = 2.2, OCT = 2.7, HRT = 7.0). Among the results of OCT and GDx, there was a significant correlation when comparing the first (r=0.46, P<.0001) and second examinations (r=0.52, P<.0001). However there was no significant relationship between the data provided by HRT for the two remaining instruments (P>.05). CONCLUSIONS: There is a wide variation in the inter-individual and inter-test measurement of the thickness of the of nerve fibers layers using HRT. GDx has, in this respect, slight advantages over OCT.

Detection of morphological and functional progression in initial glaucoma.

BACKGROUND: To observe the prospective follow-up results of functional and morphological data in patients with early, moderate and suspected glaucoma. METHODS: Eyes (n=156; average mean defect (MD)=2.2 dB) were examined every 3 months for an average of 3.6 years. Progression was estimated using regression analysis of the indices rim area and Glaucoma Probability Score of the Heidelberg retinal tomograph, mean thickness of the fibre layer using laser polarimetry with corneal compensation, MDs of standard, Pulsar and frequency doubling technology perimetries, and the threshold noiseless trend (TNT) program for the standard and Pulsar perimetries. RESULTS: TNT showed more than twice the diagnostic capacity of other methods. The maximum diagnostic sensitivity was obtained with TNT Pulsar. This procedure indicated progression in 40% of cases after seven examinations, and presented the lowest number of cases of progression not confirmed in two consecutive examinations. Most of the progressions of initial glaucoma were diffuse, without changes in the lens or loss of visual acuity. Heidelberg retinal tomograph and laser polarimetry made few diagnoses of progression. The diagnostic agreement between different methods was low, but higher between functional than morphological procedures. CONCLUSION: Functional indices, especially Pulsar, showed better detection of progression than morphological indices.

K+ channel blockers: novel tools to inhibit T cell activation leading to specific immunosuppression.

During the last two decades since the identification and characterization of T cell potassium channels great advances have been made in the understanding of the role of these channels in T cell functions, especially in antigen-induced activation. Their limited tissue distribution and the recent discovery that different T cell subtypes carrying out distinct immune functions show specific expression levels of these channels have made T cell potassium channels attractive targets for immunomodulatory drugs. Many toxins of various animal species and a structurally diverse array of small molecules inhibiting these channels with varying affinity and selectivity were found and their successful use in immunosuppression in vivo was also demonstrated. Better understanding of the topological differences between potassium channel pores, detailed knowledge of toxin and small-molecule structures and the identification of the binding sites of blocking compounds make it possible to improve the selectivity and affinity of the lead compounds by introducing modifications based on structural information. In this review the basic properties and physiological roles of the voltage-gated Kv1.3 and the Ca2+-activated IKCa1 potassium channels are discussed along with an overview of compounds inhibiting these channels and approaches aiming at producing more efficient modulators of immune functions for the treatment of diseases like sclerosis multiplex and type I diabetes.

Antimicrobial peptide induction in the haemolymph of the Mexican scorpion Centruroides limpidus limpidus in response to septic injury.

Antimicrobial peptides (AMPs) are essential components of host defences against infectious microrganisms. In chelicerate organisms they have been implicated in three alternative defensive systems: one is defined by the immediate up-regulation of genes encoding AMPs, another is characterized by the inducible systemic release of AMPs from cellular reservoirs and the third alternative is the systemic constitutive production of AMPs. In this work we used a differential high-performance liquid chromatography and mass spectrometry approach to show that septic injury elicits an immune response in the haemolymph of the Mexican scorpion Centruroides limpidus limpidus. We isolated several haemolymph components, one of which was characterized extensively (amino acid sequence, disulphide pairing, cDNA and genomic clones) and demonstrated to be a novel member of the invertebrate defensin family and consequently named C. limpidus limpidus defensin-like peptide (Cll-dlp). This peptide accumulates in the haemolymph in response to septic injury, independently of transcriptional regulation.