Water, trachoma and conjunctivitis.

The incidence of eye infections in a community is generally accepted as an indicator of the adequacy of water supply for their needs. However, discrepancies in the published results from various studies seem to challenge this view. We have reanalysed the published data on trachoma in relation to the most relevant indicators of water accessibility, using prevalence ratios as the single parameter for risk assessment. A definite trend emerges from this review: the incidence of infectious conjunctivitis is not sensitive to differences in water accessibility; on the other hand, a reduction in the risk of trachoma is consistently associated with better access to water. This conclusion may support the efforts of WHO and other multilateral and bilateral agencies to sustain the commitment towards the water supply sector beyond the International Drinking Water Supply and Sanitation Decade.     

Pituitary fossa: chemical shift effect in MR imaging

The effect of chemical shift on magnetic resonance (MR) imaging of the pituitary fossa was studied. Healthy volunteers underwent conventional MR imaging of the pituitary fossa and then imaging with the frequency-encoding gradient reversed or with the phase- and frequency-encoding gradients interchanged. Comparison of the image pairs in each subject showed that the thin, black stripe evident at the water-fat interface within the pituitary fossa was altered when the gradients were changed. Therefore, the low-intensity signal within the pituitary fossa is a chemical shift misregistration effect.     

Experimental studies on the pathogenesis of retinopathy of prematurity.

The angiogenic activity of various parts of the retina in kittens with oxygen-induced retinopathy has been studied by the use of a corneal micropocket technique and chorioallantoic assay. The results indicate that in retinopathy of prematurity the most important role in the pathogenesis of fibrovascular proliferation is played by the so-called primary avascular retina, that is, that part of the retina which has not yet been vascularised during ontogenesis.     

The major cicatricial pemphigoid antigen is a 180-kD protein that shows immunologic cross-reactivities with the bullous pemphigoid antigen.

Recent studies have shown that sera from patients with cicatricial pemphigoid (CP) contained autoantibodies against epidermal antigens of molecular weight 230 kD and/or 180 kD by immunoblotting, similar to those recognized by bullous pemphigoid (BP) sera. Previous immunoprecipitation studies have shown that BP sera only precipitated the 230-kD antigen. To characterize the CP antigen(s) we tested 10 CP sera, 10 BP sera, and four controls by both immunoprecipitation of radiolabeled cells and immunoblotting of epidermal extracts. For immunoprecipitation, we used 0.5% NP-40 extracts of both normal human keratinocytes and Pam cells. All CP sera precipitated a 180-kD protein that co-migrated with the BP180 antigen precipitated by some individual BP sera. Two of these CP sera also faintly bound a 230-kD protein of similar molecular weight as the major BP230 antigen. CP and BP sera with an immunoblotting pattern of 180 kD immunoprecipitated a co-migrating 180-kD protein. CP sera reacting by immunoblotting with the 230-kD antigen precipitated the 180-kD and/or the 230-kD antigen. In contrast, BP sera reacting with the 230-kD antigen only precipitated this antigen. In further experiments, labeled 0.5% NP-40 extracts from Pam cells were first preabsorbed with a reference BP serum and then immunoprecipitated with CP sera. Under these conditions, CP sera that immunoprecipitated both 180-kD and 230-kD proteins with the standard procedure no longer precipitated these proteins. Our results suggest that a 180-kD protein is the major CP target-antigen that demonstrated immunologic cross-reactivities with the BP180 and the BP230 antigens.     

A polymorphic variant of the gene coding desmoglein 1, the target autoantigen of pemphigus foliaceus, is associated with the disease

Two polymorphic markers were identified on the desmoglein 1 gene which encodes the autoantigen targeted by pathogenic antibodies in pemphigus foliaceus (PF), a cutaneous autoimmune blistering disease. The first marker, made of a variant haplotype of five mis-sense mutations located on the part of the gene encoding the fourth and fifth extracellular domains of the protein, is not associated with the disease. The second marker consists of a single silent T to C transition at position 809 and was found to be significantly more frequent (P = 0.015) in Caucasian PF patients (n = 36) than in controls (n = 98). Thus, pemphigus foliaceus constitutes another example of autoimmune disease in which the autoantigen polymorphism contributes to disease susceptibility.     

Immunomodulation of autoimmune and inflammatory diseases with intravenous immunoglobulin

Abstract Intravenous immunoglobulin (IVIg) has been used in the treatment of primary and secondary antibody deficiencies for over two decades. Since the early 1980s, the therapeutic efficacy of IVIg has been established in idiopathic thrombocytopenic purpura, Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, myasthenia gravis, dermatomyositis and Kawasaki syndrome, and the prevention of graft versus host disease in recipients of allogeneic bone marrow transplants. Its use has also been reported in a large number of other autoimmune and systemic inflammatory conditions. In this review, we discuss the mechanisms by which IVIg exerts immunomodulatory effects in immune pathologies.     

Comparison of human tumor cells (Hep 2) and rat liver for the detection of antinuclear antibodies by indirect immunofluorescence

Indirect immunofluorescent detection of anti-nuclear antibodies was conducted on sections of rat liver and on smears of human Hep 2 tumour cells in the serum of 1017 patients. Overall, the Hep 2 cells gave titres superior by 1 or 2 dilutions. Taking into account this difference, a good agreement was observed between the 2 cellular reagents in 83 per cent of the sera tested. The divergences, which affect almost one half of the positive sera, are largely due to the presence of anti-centromere antibodies, anti-nuclear antibodies giving a patchy "M3" appearance to the Hep 2 cells and, most importantly, anti-nucleolar antibodies. Such differences demonstrate that there are major qualitative or quantitative antigenic differences between the nuclei of rat hepatocytes and those of Hep 2 cells. Although technically rat liver and Hep 2 cells were found to be fairly easy to use and interpret, only a large comparative study of human pathology will be able to determine which is the better reagent for the routine detection of anti-nuclear antibodies.     

Secondary ion emission microanalysis: Applications to the study of human skin

Summary Secondary ion emission microanalysis is a new method of physical analysis recently applied in biology. The apparatus required (CAMECA SMI 300) enables pictures to be taken of the distribution of certain elements, with a space resolution of the order of 1 m. Concentrations below 1 p.p.m. are perceptible for most elements.The present results are the first obtained for human skin sections. Investigation of the natural elements of normal skin reveals no particular accumulation. Elements foreign to the skin are easy to detect. We show here the distribution in the epidermis of clinical antiseptics applied locally.This method has two advantages compared to X-ray microanalysis. It is more sensitive and allows analysis of even the lightes elements. However, its use in skin penetration studies is limited because it does not permit quantitative analysis and serious interference problems may occur.This work was supported by a grant from the INSERM (A.T.P. 677899 — Contrat No. 14)