Effect of moisture protective coatings on the strength of a modern metal‐reinforced glass–ionomer cement

SUMMARY The strength of a modern, low metal : glass ratio, metal‐reinforced glass–ionomer cement was measured evaluating a number of protective barriers: one light‐cured resin, two solvent‐based dental varnishes and petroleum jelly. The cement was exposed to water at 10 and 60 min from start of mix. The results obtained with these protecting agents were compared with those obtained where no protection was applied. A comparison of uniaxial flexural strength and biaxial flexural strength showed the latter to be more discriminating. Proprietary dental varnishes were superior to petroleum jelly, producing similar strengths of 50 MPa. Petroleum jelly was, however, preferable to no protection. Moisture protection during the first 30min was found to be beneficial, thereafter no further strength increase was found. A second material, a cermet which has a high metal : glass ratio, was found to be more moisture resistant but weaker in strength than the modern material, with a biaxial strength of 39 MPa.     

T cells reactive with the NC16A domain of BP180 are present in vulval lichen sclerosus and lichen planus

Background Lichen sclerosus (LS) is a chronic inflammatory skin condition. The recent demonstration of circulating autoantibodies to extracellular matrix protein 1 and to basement membrane zone (BMZ) components, chiefly BP180, suggests that autoimmunity to these components might contribute to pathogenesis. However, there is no binding of autoantibodies in vivo and as LS is characterized by a lymphocytic infiltrate, it seems likely that LS is mediated, in part, by antigen‐specific lymphocytes. Similar mechanisms may apply to vulval lichen planus (LP), an interface dermatitis, with clinical and immunological overlap with LS. Objectives This study aims to test the hypothesis that T cells reactive with the NC16A domain of BP180 are present in the peripheral blood of patients with vulval LS and LP. Methods Isolated peripheral blood mononuclear cells from 14 patients with vulval LS, 5 with vulval LP and 4 healthy controls were grown in vitro. We examined for immunogenicity of overlapping peptides spanning the NC16A domain of BP180 using interferon‐γ enzyme‐linked immunospot assay (ELIspot) on the cultured T‐cell lines. BMZ antibodies were assayed, HLA type determined and clinical parameters noted. Results Significant interferon‐γ production was observed in response to the NC16A peptides in 6 of the 14 vulval LS and 2 of the 5 LP patients, but not in the control subjects. There was an associated autoantibody response to BP180 in 3 LS and 1 LP patient with T‐cell responses. These data suggest that in some vulval LS and LP patients, NC16A domain‐specific T cells circulate at sufficiently high frequency to be detectable in vitro and show rapid effector function. There was no association with HLA type or clinical parameters. Conclusion We have demonstrated that in > 40% of our vulval LS and LP patients, the NC16A domain of BP180 is a target for circulating T cells, and in vulval LS and LP there are associated autoantibodies to BP180.     

The treatment of macular holes by pars plana vitrectomy and internal air/SF6 exchange

The results of a series of patients with full-thickness macular holes treated by pars plana vitrectomy are described. A air/gas mixture is used to tamponade the retinal hole and no adhesion is applied. Eleven eyes, including six high myopes, were treated using this method and sustained reattachment was achieved in eight eyes (73%). Three cases failed due to the presence of preretinal membrane formation and retinal shortening. This method is technically easy, allows good tamponade of the retinal hole with controlled internal drainage of subretinal fluid, and appears much safer than previously described techniques.Presented at the 1984 meeting of the Club Jules Gonin in Lausanne, Switzerland     

Vena caval filter to prevent pulmonary embolism: experimental study. Work in progress

A new inferior vena caval filter was tested in an experimental series of 23 dogs and in an in vitro study. The filter consists of a pliable basket and anchoring legs made of stainless steel. It can be inserted percutaneously in an antegrade or retrograde fashion through a 10-F Teflon catheter and can be retrieved with a snare or forceps. The filter is self-orienting in the inferior vena cava, becomes securely the inferior vena cava, becomes securely fixed to the wall, and has exhibited no tendency to migrate. It is highly effective in capturing small and large emboli. There was no significant elevation in upstream hydrostatic pressure following entrapment of emboli. Spontaneous thrombus formation within the basket was observed in two of six dogs who had short-term follow-up. In dogs who had long-term follow-up, the filter remained patent. Microscopically, the filter caused sclerosis of the intima where the wire was in contact with the vessel wall. Breakage of an anchor leg and separation at the fusion between anchor and basket were seen in the study. They were eliminated by improvement of the prototype, which is now ready for clinical application.     

MR imaging in patients with metallic implants

A total of 305 magnetic resonance (MR) examinations were performed in 236 patients with metallic implants. Most examinations were performed at 0.3 T. The metallic implants included central nervous system shunting devices, tantalum mesh, surgical wire, skin staples, surgical clips, metallic orthopedic devices, and a few miscellaneous metallic objects. Patients with cardiac pacemakers, electrical implants, prosthetic cardiac valves, and aneurysm clips were excluded from MR examinations. The images were reviewed for evidence of metallic artifact. The conspicuity of artifact was related to the composition, mass, orientation, and position of the metallic object in the body. In most instances, the metallic artifact did not interfere with the interpretation of the image. The patients' records were also reviewed for adverse effects noted by each patient during the MR examination. Only two patients reported discomfort that could possibly have been related to their metallic implants, but in both cases it seemed unlikely that the symptoms were actually related to the imaging process. There were no apparent short-term adverse effects demonstrated in these patients.