Unusual associations of pattern dystrophies

Pattern dystrophies are a group of inherited abnormalities of the macular pigment epithelium. They include reticular, macroreticular and butterfly-wing dystrophies. Several cases of pattern dystrophies associated with other diseases are reported. In one patient with reticular dystrophy of the retinal pigment epithelium this was combined with congenital hereditary deafness. Both affections were probably transmitted by a single pleiotropic gene. Apart from the typical reticular pattern in the macula there were atrophic areas that could have resulted from progression of the dystrophy. The two other cases were from the same family, one member showing macroreticular dystrophy associated with vitelliform macular dystrophy, and another a butterfly-wing dystrophy. These findings confirm the observation that different pattern dystrophies can occur in the same family and prove that such lesions can be associated with vitelliform dystrophy. The hypothesis is raised that pattern dystrophies and vitelliform dystrophy, although presently described as different clinical entities, are a single disease expressed in various manners.     

Psychophysical and electrofunctional contrast sensitivity in cataractous patients treated with bendazac-lysine salt

The clinical progression of the cataract may be influenced by drugs which reduce the denaturation of lens proteins. One of the most promising drugs is the bendazac-lysine salt. The drug was used in a double-blind study of a group of patients with initial cortical cataract in order to evaluate the changes in visual acuity and contrast sensitivity by means of a psychophysical and an electrophysiological method. After 6 months of treatment with bendazac the mean values of visual acuity showed a statistically significant increase in respect to baseline values, as well as an improvement of the threshold of contrast for most spatial frequencies. In the eyes treated with placebo there was no statistical difference between the visual acuity at baseline and after the treatment, but an increase of the contrast threshold for many spatial frequencies. The treatment with bendazac, when compared to the administration of placebo, leads to a statistically significant improvement of the contrast threshold and induces a global improvement on the visual conditions.     

Influence of sex steroids and prolactin on haloperidol-induced catalepsy

The effects of sex steroids and prolactin on haloperidol-induced catalepsy were investigated in male rats. Repeated administration with estradiol benzoate (5 μg/rat, twice daily for 10 days) significantly potentiated catalepsy induced by 0.25 or 0.5 mg/kg haloperidol, but no effect was observed 10 min or 1 h after a single injection of estradiol benzoate (5 or 50 μg/rat).Conversely, a single administration with the catecholestrogen 2-hydroxyestradiol (50 μg/rat) significantly increased haloperidol-induced catalepsy, suggesting that catecholestrogens may directly interfere with nigrostriatal dopaminergic transmission.Haloperidol-induced catalepsy has been found to be attenuated in conditions of hyperprolactinaemia resulting from anterior pituitary isograft underneath the kidney capsule. This is consistent with the hypothesis that prolactin may stimulate nigro-striatal dopaminergic function.Results obtained also indicate that medroxy-acetate progesterone, a progesterone derivative, may influence haloperidol-induced catalepsy. Specifically, a single administration with medroxy-acetate progesterone (5 mg/kg, i.p.) enhanced catalepsy but opposite effects were observed after repeated administration of medroxy-acetate progesterone (5 mg/kg, i.p., once a day for 7 days).     

Characterization of receptors for alpha-melanocyte-stimulating hormone on human melanoma cells

Receptors for alpha-melanocyte-stimulating hormone (alpha-MSH) on human malignant melanoma cell lines were investigated with a specific binding assay and characterized with structural analogues of alpha-MSH and adrenocorticotropic hormone and by photoaffinity cross-linking of the hormone-receptor complex. Specific binding of high-performance liquid chromatography-purified, monoiodinated alpha-MSH in the presence of 1 mM 1,10-phenanthroline as protease inhibitor was highest after a 2-h incubation at 37 degrees C. The nonspecific binding was less than 20% and dissociation of the ligand-receptor complex was relatively slow. Ten out of 12 human cell lines showed specific binding sites for alpha-MSH with Kp values ranging from 0.195 to 2.87 nM and the sites/cell being approximately 400 to approximately 1600. Virtually identical results were obtained in an assay where the cells remained attached to the culture dishes during the entire experiment. The study of hormone analogues with the D10 cell line showed that oxidized alpha-MSH had an approximately 40-fold lower affinity than alpha-MSH whereas [Nle4,D-Phe7]-alpha-MSH displayed a threefold and the adrenocorticotropic hormone fragments (1-17) and (1-24) a 20- and 8-fold higher affinity. Cross-linking of the alpha-MSH-receptor complex of three cell lines using monoiodinated [Nle4,D-Phe7,Trp(2-nitro-4-azidophenylsulfenyl)9]-alpha-MSH as photoaffinity label revealed a major Mr 45,000 protein band on sodium dodecyl sulfate-polyacrylamide gels, analogous to the MSH receptor of mouse B16 melanoma cells.     

Cavernous hemangioma of the retina and retinal telangiectasis. Distinct or related vascular malformations?

Cavernous hemangioma of the retina and retinal telangiectasis are two rare developmental vascular lesions of the retina. They are considered to be distinct clinical entities, but they share some common features, so that the differential diagnosis of the two diseases is an important clinical challenge. In the right eye of a young woman, a cavernous hemangioma of the retina close to an area of retinal telangiectasis was found. This association supports the possibility that these developmental anomalies could be strictly related.