Biomedical subjects

V Chatzis

Publications and source records attributed to V Chatzis.

4 recordsLinked to original sources

PubMed2000

Interpolation of 3-D binary images based on morphological skeletonization.

In this paper, the morphological skeleton interpolation (MSI) algorithm is presented. It is an efficient, shape-based interpolation method used for interpolating slices in a three-dimensional (3-D) binary object. It is based on morphological skeletonization, which is used for two-dimensional (2-D) slice representation. The proposed morphological skeleton matching process provides translation, rotation, and scaling information at the same time. The interpolated slices preserve the shape of the original object slices, when the slices have similar shapes. It can also modify the shape of an object when the successive slices do not have similar shapes. Applications on artificial and real data are also presented.

Algorithms↗

PubMed1996

Intravitreal application of ganciclovir in rabbits: ERG and electron-microscopic findings.

The retinal toxic effect after intravitreal use of ganciclovir has been the subject of our experimental investigation on 20 New Zealand rabbits. Different doses of ganciclovir ranging from 200 to 600 micrograms/0.1 ml were injected intravitreously, and ERG changes were recorded at different time points after drug administration. Finally the animals were killed and the retinal lesions were studied by electron microscopy. According to our experiments, ganciclovir doses of 300-600 micrograms/0.1 ml have a clearly toxic effect on the retina as shown by ERG changes. One month after the injection, the electroretinogram is either extinguished or clearly affected. Noteworthy is the fact that in a dose of 200 micrograms/0.1 ml, the ERG b-wave shows a 20% reduction of its normal amplitude 4 months after ganciclovir delivery. Electron microscopy of the retina revealed in the inner segment of the receptor cells the existence of dilatation and vesiculation of the endoplasmic reticulum in the surrounding nuclear cytoplasm and swelling of the mitochondria with fragmentation of the cristae in several of them. In the outer segment of the photoreceptor cells, degeneration and destruction of the lamellae accompanied by disintegration of the adjacent protoplasm in parts of certain rods and cones appeared. Finally large vacuoles of irregular shape in the synapses and degenerative mitochondria and empty vacuoles in the optic nerve fibers were shown.

Animals↗

PubMed1993

C-wave study in cone dysfunction syndrome.

An electroretinogram (ERG) and C-wave were recorded from 15 patients suffering from cone dysfunction syndrome. Our results show that the photopic ERG was diminished with extinction of the oscillatory potentials. On the other hand, the mean value of the C-wave amplitude was diminished and the implicit time prolonged. This may serve as a further diagnostic sign of the disease.

Adolescent↗

PubMedDate not supplied

Spontaneous recovery of progressive anterior ischemic optic neuropathy.

During the last 5 years much discussion has occurred about the progressive anterior ischemic optic neuropathy of nonarteretic type and the usefulness of surgical optic nerve sheath decompression for its treatment. The description of cases with spontaneous recovery of the disease made some authors reserved or against this method and the whole subject has been debated with skeptisism. In this article three cases of progressive nonarteretic anterior ischemic optic neuropathy with spontaneous recovery are described. In all these cases visual acuity, as well as visual evoked responses, was spontaneously ameliorated and the optic disc swelling was resolved. Only the visual fields defects remained almost the same. The question arising from this study is whether or not surgical optic nerve sheath decompression in these cases was the only appropriate method of treatment, as some authors propose.

Aged↗