Toxic effects of phenothiazines on the eye

Publications about the retinotoxic action of phenothiazine derivatives led the author to undertake an ophthalmological investigation in two psychiatric hospitals in The Netherlands. The pharmacological actions of phenothiazine preparations are listed and a survey of the phenothiazine derivatives which are at present in use is given. Some retinotoxic substances are discussed and a survey is given of the literature on the ocular complications of phenothiazine therapy. The eyes of 561 patients were examined. of whom 541 are included in this study. 343 of these patients(63.4 %) were found to have retinopathy. The correlation between the retinopathy and the total dose of phenothiazine preparations taken. and between the retinopathy and the duration of treatment. was highly significant. The correlation between the retinopathy and the average daily dose taken was significant. The retinopathy was associated with a reduced standing potential of the eye. as determined by electro-oculography. It was possibly responsible for diminished visual acuity in some cases, and for an abnormally large proportion of protans in the group of patients with colour defects. It was not possible to ascribe a more severe retinotoxic action to one or more specific phenothiazine derivatives than to others. In the author's opinion regular examination of the eyes of patients who are being treated with phenothiazine preparations in high dosage and for for a long period of time is indicated

Germanium enrichment in supergene settings: evidence from the Cristal nonsulfide Zn prospect, Bongará district, northern Peru

Supergene nonsulfide ores form from the weathering of sulfide mineralization. Given the geochemical affinity of Ge to Si4+ and Fe3+, weathering of Ge-bearing sulfides could potentially lead to Ge enrichments in silicate and Fe-oxy-hydroxide minerals, although bulk rock Ge concentrations in supergene nonsulfide deposits are rarely reported. Here, we present the results of an investigation into Ge concentrations and deportment in the Cristal supergene Zn nonsulfide prospect (Bongará, northern Peru), which formed from the weathering of a preexisting Mississippi Valley-type (MVT) sulfide deposit. Material examined in this study originates from drillcore recovered from oxidized Zn-rich bodies ~ 15–20 m thick, containing ~ 5–45 wt% Zn and Ge concentrations ~ 100 ppm. Microanalysis and laser ablation-ICP-MS show that precursor sphalerite is rich in both Fe (mean Fe = 8.19 wt%) and Ge (mean Ge = 142 ppm). Using the mineral geothermometer GGIMFis—geothermometer for Ga, Ge, In, Mn, and Fe in sphalerite—proposed by Frenzel et al. (Ore Geol Rev 76:52–78, 2016), sphalerite trace element data from the Cristal prospect suggest a possible formation temperature (TGGIMFis) of 225 ± 50 °C, anomalously high for a MVT deposit. Germanium concentrations measured in both goethite (mean values 100 to 229 ppm, max 511 ppm) and hemimorphite (mean values 39 to 137 ppm, max 258 ppm) are similar to concentrations measured in hypogene sphalerite. Additionally, the Ge concentrations recorded in bulk rock analyses of sphalerite-bearing and oxidized samples are also similar. A persistent warm-humid climate is interpreted for the region, resulting in the development of an oxidation zone favoring the formation of abundant Zn hydrosilicates and Fe hydroxides, both able to incorporate Ge in their crystal structure. In this scenario, Ge has been prevented from dispersion during the weathering of the Ge-bearing sulfide bodies and remains in the resultant nonsulfide ore