Platelet serotonin and magnesium concentrations in suicidal and non-suicidal depressed patients.

The pathophysiology and treatment of depression involves monoamine neurotransmitters and the magnesium (Mg)-modulated monoaminergic pathway. Serum and platelet Mg concentrations and platelet serotonin concentrations were measured in 79 depressed patients who had attempted suicide, and 101 patients without suicidal behaviour, according to the ICD-10 diagnoses F 33.2 and F32.2, with or without intentional self-harm (X60-X84). The control group consisted of 77 voluntary blood donors. The platelet serotonin concentration was determined using the competitive enzyme immunoassay test: Mg concentrations in platelets and serum were determined by atomic absorption spectrophotometry. The ANOVA test showed significantly lower serum Mg in the group of depressive patients who had attempted suicide (N = 257, F = 8.32, p<0.001), compared to depressive patients who had not, and the control group. Serum albumin was lower in the group of depressive patients who had attempted suicide and showed a significant, positive correlation with serum Mg concentrations. Platelet Mg concentrations were found to be higher in depressive patients who had not attempted suicide (N = 257, F = 3.90, p = 0.012) compared to the control group, with no difference compared to depressive patients who had attempted suicide. The Kruskal Wallis test (N = 257, H = 48.54, p<0.0001) showed the lowest concentration of platelet serotonin in the groups of depressed patients with and without suicidal behaviour, compared to the healthy control group. A positive correlation was found between platelet Mg and serotonin concentrations only in the healthy control group. In conclusion, differences were observed in serum and platelet Mg concentrations, which represent progress in the study of Mg status and its relation to serotonin.

Cognitive-psychomotor functions and nutritional status in maintenance hemodialysis patients: are they related?

Both cognitive impairment and malnutrition are common in hemodialysis patients and associated with adverse clinical outcome. The aim of the study was to investigate performance on a detailed cognitive and psychomotor battery in maintenance hemodialysis patients in correlation to nutritional status. A selected population of 65 adult (20 females and 45 males, aged 57.84±12.28 years) hemodialysis (4.78±3.62 years) patients were investigated. The total time of test solving was correlated with Dialysis Malnutrition Score (DMS) in tests of simple visual discrimination of signal location (r=0.215, P=0.042), simple convergent visual orientation (r=0.262, P=0.020), and convergent thinking (r=0.244, P=0.034). The minimum time of test solving was also correlated with DMS in the test of simple convergent visual orientation (r=0.227, P=0.038), and in the test of convergent thinking (r=0.223, P=0.048). Total ballast, as a descriptor of stability in reaction time, was correlated with DMS in the test of simple visual discrimination of signal location (r=0.281, P=0.012), and in a test of short term memory actualization (r=0.239, P=0.028). Furthermore, significant correlation was noted between body mass index, serum creatinine, total cholesterol and albumin level with cognitive-psychomotor performance. Hemodialysis patients with a poorer nutritional status performed worse on cognitive and psychomotor tests. Further research is needed to assess the effects of treating malnutrition on cognitive-psychomotor performance in these patients.

Human plasma glycome in attention-deficit hyperactivity disorder and autism spectrum disorders.

Over a half of all proteins are glycosylated, and their proper glycosylation is essential for normal function. Unfortunately, because of structural complexity of nonlinear branched glycans and the absence of genetic template for their synthesis, the knowledge about glycans is lagging significantly behind the knowledge about proteins or DNA. Using a recently developed quantitative high throughput glycan analysis method we quantified components of the plasma N-glycome in 99 children with attention-deficit hyperactivity disorder (ADHD), 81 child and 5 adults with autism spectrum disorder, and a total of 340 matching healthy controls. No changes in plasma glycome were found to associate with autism spectrum disorder, but several highly significant associations were observed with ADHD. Further structural analysis of plasma glycans revealed that ADHD is associated with increased antennary fucosylation of biantennary glycans and decreased levels of some complex glycans with three or four antennas. The design of this study prevented any functional conclusions about the observed associations, but specific differences in glycosylation appears to be strongly associated with ADHD and warrants further studies in this direction.

Platelet monoamine oxidase activity in children with attention-deficit/hyperactivity disorder.

Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable developmental disorder characterized by symptoms of impulsivity, hyperactivity and/or inattention, and associated with structural and biochemical abnormalities in cortical and limbic structures innervated by dopamine, noradrenalin and serotonin. The enzyme monoamine oxidase, type B (MAO-B), is expressed in platelets, and metabolizes endogenous amines. Its activity has been proposed to represent a peripheral marker of various traits and forms of psychopathology. This study evaluated platelet MAO activity with a spectrofluorimetric method in 72 boys and 12 girls with predominantly hyperactive, predominantly inattentive, and combined subtype of ADHD (DSM-IV criteria), and in 64 control children. The results showed significantly lower platelet MAO activity in children with hyperactive, inattentive, and combined subtype of ADHD than in control children. There was no significant association between platelet MAO activity and gender or age. The limitation of the study was in the small sample of girls with ADHD (N=12), and in the determination of only one peripheral marker. In line with hypotheses of lower platelet MAO activity in different types of psychopathology, children with different subtypes of ADHD had significantly lower platelet MAO-B activity than control children.