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Biomedical subjects

F Malecaze

Publications and source records attributed to F Malecaze.

At least 73 records · Page 4Linked to original sources

[Alleviation of ocular complications of the hyperviscosity syndrome in Waldenström's macroglobulinemia using plasma exchange].

Two patients presenting ocular complications of hyperviscosity syndrome in Waldenström's macroglobulinemia have been treated by plasmapheresis after inefficiency of immunosuppressive therapy. Plasma exchange seems an useful treatment as shown by clinic and angiographic improvement. In each case improvement of retinopathy was correlated with decrease of serum IgM level and blood viscosity measured by isotopic method. Fluorescein angiography, easily repeated, seems a very good method for following hyperviscosity syndrome in Waldenström's macroglobulinemia.

Aged↗

Candida endophthalmitis after heroin abuse.

Three cases of ocular candidosis involving heroin abusers have been observed in 1983 in Toulouse department of ophthalmology. These three patients had used iranian brown heroin. Twenty similar cases have been published in these last years. This new pathology can be explained on two reasons. The first is that the drug abusers have some immunity pertubation; however, immunity exploration in these patients does not reveal any immunodeficiency. The second reason, certainly more important, is the method of using heroin. The diagnosis of Candida endophthalmitis of course based on clinical context must be proved by biological tests. Candida albicans is never identified in aqueous humor. For this reason, it seems very interesting to detect anti-candida antibodies in aqueous humor. It has been used as methods of dosage laser Nephelemetry for IgG and immunofluorescence for candidosis antibodies. The criterion used is similar to the toxoplasmosis coefficient established by Desmonts (3). In two cases, this test was the only way that permits us to have certitude of candidosis ocular diagnosis. Otherwise the observations show that anterior chamber punction is more significant when there is an anterior uveitis.

Adult↗

Some ultrastructural aspects of the vitreoretinal juncture.

The ultrastructural study of the vitreoretinal juncture was carried out by comparing two groups of patients: 6 young subjects under 25 years and 6 older subjects over 70. Retinal samples were taken from the posterior pole, the equator and the extreme periphery. Our work shows that the morphological modifications of the vitreoretinal juncture during the aging process vary following location. The most original alteration, never observed before, appears in the equatorial region: it consists of a widening of the intercell space filled with fibrils adhering to Müller's cells. It builds up an adhesion zone between the vitreous and the retina which is not visible during clinical investigations; it can create a tear during the posterior vitreous detachment.

Adolescent↗

[Lattice degeneration of the peripheral retina: ultrastructural study].

The ultrastructural study of a case of snail track degeneration shows the presence of lipid inclusions in both the glial and the macrophage cells in every layer of the retina, and the existence of intraretinal fibers different from collagen fibers appearing to be glial filaments similar to those found in astrocytic gliomes and to the Rosenthal fibers observed in senile nervous cells. Other features were thinning of the retina and absence of blood vessels in the retina. There are no abnormalities of the vitreo-retinal juncture. All the lesions are in agreement with those observed by Daicker [Ophthalmologica, Basel 165: 360-365, 1972; Klin. Mbl. Augenheilk. 172: 581-583, 1978] with some differences, however. They are different from those found in lattice degeneration. They show that snail track degeneration is a specific form of peripheral retinal degeneration which is quite different from lattice degeneration and must not be considered similar.

Choroid Neoplasms↗

[Ultrastructural study of the photoreceptors of the human retina during aging].

The ultra-structural study of the photoreceptors in the human retina during the aging process was carried out by comparing two groups of patient: 6 young subjects under 25 years of age, and 6 older subjects over 70. Retinal samples were taken from the posterior pole and treated with the classical techniques of electron microscopy. Our works show that during the aging process, nuclear and cytoplasmic morphological modifications are observed. The observation about nuclear modifications is in full agreement with aging process theories according to which the genome plays an essential part. On the other hand, no modification of the external article could be so far observed. Further works will perhaps allow to discover a decrease of the renewal process of the photoreceptor discs.

Adolescent↗

Ocular dominance columns in the adult New World Monkey Callithrix jacchus.

In the marmoset Callithrix jacchus, ocular dominance columns (ODC) have been reported to be present in young animals, but absent in adults (Spatz, 1989). We have studied in juvenile and adult animals the postnatal organization of the retino-geniculo-cortical afferents by means of transneuronal labeling. We show in the present work that ODC are present in the primary visual cortex of Callithrix jacchus, both in the adult and in the juvenile animal. The present work confirms the presence of ODC in the visual cortex of juvenile marmoset before the end of the first postnatal month. In 2-month-old animals, ODC are well demarcated in IVcalpha and IVcbeta. In the adult marmosets, the present data clearly show that the primary visual cortex is also organized with ODC. In horizontal sections, they form a mosaic through the ventral and dorsal calcarine cortex and through the dorso-lateral occipital part of the striate cortex. In frontal sections, their presence is manifest in IVcbeta within the calcarine cortex and they only faintly appear in IVcalpha. These new findings are important since they underline the usefulness of the adult New World Monkeys as a model in visual research.

Aging↗

[Plasmapheresis and acute attacks of uveitis].

Our study concerns the effects of plasma exchange in acute attacks of posterior or total chronic uveitis. The treatment undertaken in 10 patients consisted of 8 plasma exchanges in a 2 weeks period, associated with a corticosteroid and immunosuppressive therapy. Immediately after the plasma exchanges, there was a significant improvement in visual acuity and a decrease in inflammatory activity in most patients (70%). Plasma exchange seems to be an interesting adjuvant in the difficult treatment of some uveitis.

Acute Disease↗