Effect of melatonin supplementation on plasma lipid hydroperoxides, homocysteine concentration and chronic fatigue syndrome in multiple sclerosis patients treated with interferons-beta and mitoxantrone.

UNLABELLED: Multiple sclerosis (MS) prevalence is higher in geographic regions with less sunlight exposure. Melatonin participates in the effects of sunlight in healthy individuals and could play a role in MS pathophysiology. Melatonin crosses the blood-brain barrier and exerts antioxidative, immunomodulatory, and anti-inflammatory effects. Chronic fatigue syndrome concerns 80 - 90% MS patients. The pathophysiology of chronic fatigue syndrome is unknown, however activation of immune, inflammatory, oxidative and nitrosative stress mechanisms and plasma lipid peroxide elevation was reported. Homocysteine increases plasma lipid hydroperoxides levels. The aim was to determine the effect of melatonin supplementation on chronic fatigue syndrome in MS patients and evaluate plasma lipid hydroxyperoxides (LHP) and homocysteine concentrations as a potential biochemical fatigue biomarkers. Into a case-control prospective study 102 MS patients divided according receiving immunomodifying MS treatment into groups: RRMS-pretreated, RRMS-INF-beta, SP/PPMS-mitoxantrone, RRMS-relapse were enrolled. Patients were supplemented with melatonin over 90 days. Plasma LHP, homocysteine concentration, brain MRI and fatigue score were examined. Results show that LHP concentrations were significantly higher in all studied MS groups vs. CONTROLS: In all MS patient groups melatonin application resulted in significant decrease in plasma LHP concentrations. Plasma homocysteine concentration was similar in healthy people, RRMS-pretreated, RRMS-INF-beta and SP/PP-MS-mitoxantrone groups. However, in the RRMS-relapse group plasma levels of homocysteine were significantly higher compared to the RRMS-pretreated group. There were no significant differences in plasma homocysteine concentration in the studied groups before and after melatonin application. The fatigue score was significantly lower in RRMS pretreated group compared to RRMS-INF-beta and SP/PP MS-mitoxantrone treated patients. Plasma lipid hydroxyperoxides could be potential biochemical chronic fatigue syndrome biomarker in MS patients and homocysteine could be a potential marker of acute phase of MS. Melatonin exerts beneficial effects in MS patients based on its' proved antioxidative properties.

Seasonal population dynamics of the potato psyllid (Hemiptera: Triozidae) and its associated pathogen "Candidatus Liberibacter solanacearum" in potatoes in the southern great plains of North America.

The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), and its associated pathogen "Candidatus Liberibacter solanacearum" (Ca. L. solanacearum), the putative causal agent of zebra chip (ZC) disease in potatoes (Solanum tuberosum L.), were sampled in commercial potato fields and untreated control plots for 3 yr in multiple locations in Texas, Kansas, Nebraska, and Colorado. Populations of the potato psyllid varied across years and across potato growing regions. However, the percentage of potato psyllids infected with Ca. L. solanacearum although variable across years, was consistently highest in the Lower Rio Grande Valley of Texas (LRGV), the reported overwintering location for this pest. The numbers of Ca. L. solanacearum-infected psyllids collected on field traps and large nymphs counted on leaf samples were both positively correlated with the final percentage of ZC in tubers. In the LRGV, where vector and disease pressure is the highest, population levels of immature life stages of the psyllid and percentage of ZC differed greatly between commercial and untreated fields. These results show that the pest management program that was used can be effective at controlling development of the psyllid and ultimately reducing the incidence of ZC.