Ultrastructure of different clinical forms of oral leukoplakia

Twelve cases of oral leukoplakia were studied at the light and electron microscopic levels. In clinical leukoplakia simplex and verrucosa, both light and electron microscopic investigations revealed evidence of increased keratinization. Clinically erosive and histiologically dysplastic leukoplakias showed ultrastructural alterations characteristic of oral carcinomas in some instances.

[Scanning electron microscopy of oral leukoplakia]

Buccal mucosa of six patients with leukoplakia and normal controls was examined by scanning electron microscopy. Findings have shown that: 1. there is a difference between the surface epithelial cells of the normal mucosa and those of the mucosa with leukoplakia; 2. according to the various clinical forms of the leukoplakia there are differences between the epithelial cells: in leukoplakia verrucosa presence of keratinized epithelial cells, in leukoplakia erosiva absence of the cell-connecting structures seems to be a characteristic feature; 3. in leukoplakia erosiva with dysplasia atypical arrangement of the cytoplasmic processes of surface epithelial cells can be observed; 4. the most striking difference was revealed between the cells of the normal mucosa and those of leukoplakia erosiva.

Early lens changes in Macaca fascicularis monkeys under topical treatment with echothiophate or carbachol studied by slit-image photography

Cynomolgus monkeys were given topical treatment with echothiophate or carbachol, and the lens changes were followed by slit-image photography. Both drugs caused an early retrodisplacement of the anterior zone of disjunction due to swelling of the most superficial lens cortex. Deeper layers of the cortex did not swell. The exact cause of the swelling is not known, but there must be a true cholinergic link. Accommodation as such is not the cause, since (1) the effect was seen also in a monkey eye which had its ciliary muscle disinserted from the scleral spur and therefore had little accommodation left and (2) acute accommodation produced by systemic pilocarpine did not cause the effect. Anterior subcapsular opacities were quantified and appeared very early in the echothiophate-treated eyes but were not seen with the doses of carbachol used.

[Ultrastructure of the mouth mucosa in various types of oral leukoplakia]

12 cases of laukoplakia of the oral cavity was studied by electron microscopy. A correlation between the clinical type, histological- and ultrastructure of the leukoplakia was revealed. In types of leukoplakia simplex and verrucosa, where histologically cornification was found, by electron microscopy signs of keratinization (tonifibrils, granules of keratohyalin) were to be observed. In leukoplakias clinically showing erosions, histologically dysplasia, ultrastructural changes were alike those, seen in some carcinomas.

Radionuclide cystography in the investigation of vesicoureteric reflux in children

50 children with urinary-tract infection and vesicoureteric reflux were investigated by direct radionuclide cystography (R.N.C.). Recent micturating cystourethrograms (M.C.U.) were used as controls. In 37 patients the results of both tests corresponded, 9 patients were M.C.U. positive only, and 4 were R.N.C. positive only. R.N.C. is associated with a considerably lower radiation dose than M.C.U.S. and intravenous urograms, it provides an accurate measurement of residual urine, and is simple to apply with equipment which is readily available. R.N.C. is a useful investigation in the diagnosis and management of reflux and a valuable complement to standard radiographic methods.

Caries prevalence of preschoolchildren in Baja, Hungary in 1955 and 1975

In 1975 caries epidemiologic investigations were performed in 1,017 preschoolchildren of Baja, aged 3--6 years. The data were analyzed and compared with those of 620 preschoolchildren of the same city in 1955. A mean increase of 10.9% of the caries frequency (percentage of examinees with caries), and a mean increase of 43.5% of the caries intensity(dmft count per examinee) could be observed in spite of a better vitamin D prophylaxis. The possible cariogenic role of the increased surgar consumption (37.5 kg from 24.4 kg per individual during 20 years) is discussed.

Automatische Erkennung von Organgrenzen in Leber-Szintigrammen

Es wurde ein Verfahren zur Bestimmung des Leberabbildes im Szintigramm geschildert. Der aktive Bereich, das Abbild aller im Szintigramm dargestellten Organe, wird zunächst mit zwei voneinander unabhängigen Verfahren bestimmt. Die Ähnlichkeit der Ergebnisse dient dann als Maß für deren Zuverlässigkeit. Bei ähnlichen Ergebnissen lagen deren Abweichungen innerhalb des Auflösungsvermögens der Gamma-Kamera.

Anschließend wird versucht, das Leberabbild vom Milzabbild zu trennen. Wenn die beiden Organe nicht bereits als zwei voneinander getrennte Gebiete dargestellt sind, wird eine Trennlinie berechnet. Dann wird untersucht, ob diese Trennlinie Leberund Milzabbild trennt oder ob die Trennlinie innerhalb des Leberabbildes verläuft.

Insgesamt konnte in 83 von den 121 automatisch analysierten Szintigrammen (69 %) das Leberabbild richtig isoliert werden, gemessen an der routinemäßig subjektiven Bildbeurteilung. Für 3 Szintigramme (2 %) lieferte das Verfahren ein falsches Ergebnis. Für die übrigen 35 Szintigramme (29 %) wurde auf eine vollständige automatische Isolation des Leberabbildes verzichtet. Das Verfahren lieferte für diese Szintigramme zwei bis vier Alternativen für die Grenzen des Leberabbildes, von denen mindestens eine den subjektiv bestimmten Grenzen entsprach.

Ist es gelungen, die Grenzen des Leberabbildes zu bestimmen, können wertvolle Befundmerkmale des Szintigramms, wie z. B. der Flächeninhalt des Leberabbildes, einfach berechnet werden.