Ultrasound biomicroscopic features of spherophakia

Background: Spherophakia is an uncommon diagnosis. This is the first case report of spherophakia evaluated by ultrasound biomicroscopy.
Methods: Ultrasound biomicroscopy is a new diagnostic technique developed by one of the authors and provides images with microscopic resolution of the anterior segment. A patient with spherophakia was evaluated by ultrasound biomicroscopy (Zeiss-Humphrey, 50MHz) before and after YAG laser iridotomy.
Results: Ultrasound biomicroscopic assessment revealed a shallow anterior chamber, a very steep anterior lens curvature, iridolenticular contact, elongated zonules, and an increased distance between the lens equator and the ciliary processes. Angle closure glaucoma was due to a pupil block mechanism. The pupil block was relieved by YAG laser iridotomy.
Conclusions: Ultrasound biomicroscopy is a useful technique to confirm the diagnosis of spherophakia. The pupil block in spherophakia is relieved by YAG laser iridotomy.     

Ocular perfusion pressures in different types of glaucoma

Summary It is widely accepted that a disturbed blood supply of the optic disc may cause (in addition with an increased intraocular pressure) optic nerve fibre damage. Therefore we measured ocular perfusion pressures in 79 healthy subjects. In 18 patients with low tension glaucoma, in 27 patients suffering from ocular hypertension and in 49 glaucoma (OAG) patients. For measuring perfusion pressures we used the technique of oculooscillo-dynamography (OODG) as described by Ulrich. Additionally we measured intraocular pressure and systemic blood pressure. In OODG the IOP is simultaneously increased in both eyes by application of a suction cup. After increase of the IOP the negative pressure in the suction cup is slowly and linearly decreased. During this decrease the pulse-depending oscillations of each eye are recorded on a strip-chart-recorder. By means of this method retinal and ciliary perfusion pressures can be separated. As a result we could show that mean arterial blood pressure and systolic retinal perfusion pressure were comparable and not statistically significantly different between the groups examined. The systolic ocular perfusion pressures in patients with low tension glaucoma showed a highly statistically significant reduction compared with the other groups. Between healthy subjects, OAG-patients and patients suffering from ocular hypertension there was no difference in systolic ciliary perfusion pressure detectable.     

New x-ray tube performance in computed tomography by introducing the rotating envelope tube technology

The future demands of computed tomography imaging regarding the x-ray source can be summarized with higher scan power, shorter rotation times, shorter cool down times and smaller focal spots. We report on a new tube technology satisfying all these demands by making use of a novel cooling principle on one hand and of a novel beam control system on the other hand. Nowadays tubes use a rotating anode disk mainly cooled via radiation. The Straton x-ray tube is the first tube available for clinical routine utilizing convective cooling exclusively. It is demonstrated that this cooling principle makes large heat storage capacities of the anode disk obsolete. The unprecedented cooling rate of 4.8 MHU/min eliminates the need for waiting times due to anode cooling in clinical workflow. Moreover, an electronic beam deflection system for focal spot position and size control opens the door to advanced applications. The physical backgrounds are discussed and the technical realization is presented. From this discussion the superior suitability of this tube to withstand g-forces well above 20 g created by fast rotating gantries will become evident. Experience from a large clinical trial is reported and possible ways for future developments are discussed.     

Coeliac disease, adenocarcinoma of jejunum and in situ squamous carcinoma of oesophagus

The development of both adenocarcinoma of the jejunum and in situ squamous carcinoma of the oesophagus in an adult coeliac patient is described. Good evidence that adenocarcinoma of jejunum occurs more frequently in patients with coeliac disease has recently become available though this association has been suggested for some time. While oesophageal carcinoma has long been associated with coeliac disease, in situ carcinoma of oesophagus has not been previously described in these circumstances. We feel that the risk of this complication, as calculated from published series, warrants a screening programme for oesophageal malignancy in adult coeliacs.     

Experimental induction of rheumatoid factor-like substances in animal trypanosomiasis

Rheumatoid factor-like substances were induced in rabbits by infection with Trypanosoma equiperdum. There was a certain parallelism with the phenomena described earlier with T. gambiense infections in man. The anti-IgG globulins were IgM with a preference for heterologous (human) IgG in the latex fixation test. A correlation was found between the latex fixation titres and the IgM levels in the sera. A naturally occurring pre-infectious agglutinator was not of IgM nature. The anti-IgG globulins developed in all the infected animals, mostly within 2 weeks and often before the IgG levels in the sera started to increase.

The failure to induce rheumatoid factor-like substances in mice infected with a certain strain of T. gambiense indicates the importance of the host–parasite relationship for the formation of rheumatoid factors.

The single radial diffusion method according to Mancini, Carbonara & Heremans (1965) did not give valid results for the determination of IgM in the rabbit sera, but could be used for IgG. IgM was determined by an indirect method.

These experiments might form the basis of a model for investigating the nature of rheumatoid factor formation.