The effect of the coinheritance of Glucose-6-phosphate dehydrogenase deficiency on the severity of sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) and glucose-6-phosphate dehydrogenase (G6PD) deficiency are inherited disorders associated with chronic haemolysis. Therefore, coinheritance of both disorders could worsen haemolysis in the former and compound a haemolytic crisis. This study compared clinical and laboratory features of deficient and non-deficient SCD patients and the G6PD activities of SCD patients and apparently healthy controls. MATERIALS AND METHODS: This is a case-control study of 175 SCD patients and 166 non-SCD controls. G6PD assay was carried out on haemolysate from washed red cells. The G6PD activity was measured by spectrophotometry. RESULTS: The mean age of patients and controls was 27.3 ± 9.4 and 35.9 ± 9.7 years, respectively, with 75 (46.2%) and 87 (52.4%) being males, respectively. G6PD activity was similar in cases and controls (6.7 ± 3.3 vs. 6.9 ± 3.0 IU/gHb), respectively (P = 0.6). The prevalence of G6PD deficiency was higher in patients than controls (28.6% vs. 22.3%, P = 0.18), and SCD patients were twice more likely to have enzyme activities below 3.0 IU/gHb. No significant difference was observed in the clinical parameters between deficient and non-deficient patients. Deficient patients were more likely to have lower haematocrit (22.8 ± 3.9% vs. 24.5 ± 5%, P = 0.04) and non-significantly higher bilirubin and reticulocyte counts. Furthermore, in patients, severe deficiency resulted in higher bilirubin than in those with mild deficiency (60.5 vs. 21.7 IU/L, P < 0.001). G6PD activity correlated positively with haematocrit (r = 0.91, P = 0.01) and mean corpuscular haemoglobin concentration (r = 0.17, P = 0.02). CONCLUSIONS: Coinheritance of both disorders could worsen haemolysis in SCD patients, and care should, therefore, be taken in the choice of drugs in deficient SCD patients.

Sex differences in the human visual system.

This Mini-Review summarizes a wide range of sex differences in the human visual system, with a primary focus on sex differences in visual perception and its neural basis. We highlight sex differences in both basic and high-level visual processing, with evidence from behavioral, neurophysiological, and neuroimaging studies. We argue that sex differences in human visual processing, no matter how small or subtle, support the view that females and males truly see the world differently. We acknowledge some of the controversy regarding sex differences in human vision and propose that such controversy should be interpreted as a source of motivation for continued efforts to assess the validity and reliability of published sex differences and for continued research on sex differences in human vision and the nervous system in general. © 2016 Wiley Periodicals, Inc.