Parkinson's disease occurs in 1% of people over the age of 65 when about 60% of the dopaminergic neurons in the substantia nigra of the midbrain are lost. Dopaminergic neurons appear to die by a process of apoptosis that is induced by oxidative stress. Oxygen radicals abstract hydrogen from DNA forming DNA radicals that lead to DNA fragmentation, activation of DNA protective mechanisms, NAD depletion and apoptosis. Oxygen radicals can be formed in dopaminergic neurons by redox cycling of MPP+, the active metabolite of MPTP. This redox cycling mechanism involves the reduction of MPP+ by a number of enzymes, especially flavin containing enzymes, some of which are found in mitochondria. Tyrosine hydroxylase is present in all dopaminergic neurons and is responsible for the synthesis of dopamine. However, tyrosine hydroxylase can form oxygen radicals in a redox mechanism involving its cofactor, tetrahydrobiopterin. Dopamine may be oxidized by monoamine oxidase to form oxygen radicals and 3,4-dihydroxyphenylacetaldehyde. This aldehyde may be oxidized by aldehyde dehydrogenase with the formation of oxygen radicals and 3,4-dihydroxyphenylacetic acid. The redox mechanisms of oxygen radical formation by MPTP, tyrosine hydroxylase, monoamine oxidase and aldehyde dehydrogenase will be discussed. Possible clinical applications of these mechanisms will be briefly presented.

BackgroundAlmonds can decrease glycemic index of co-consumed foods and are a rich source for oleic acid and α-tocopherol. The aim of the randomized, crossover, controlled feeding trial was to examine whether as compared to NCEP step II diet as control (CON), ~60 g/d almonds (ALM) added to CON would improve glucoregulation and cardiovascular disease (CVD) risk factors in 33 Chinese T2DM patients.MethodsForty T2DM patients were enrolled and randomly assigned to receive CON or ALM for 12 wks after a 2-wk. run-in period. Blood and urine samples were collected in the beginning and at the end of each dietary intervention phase for the assessment of biomarkers of glucoregulation, lipid profile, inflammation, and oxidative stress.ResultsWhile ALM had a better overall nutritional quality than CON, neither ALM nor CON improved the glycemic status as the primary study outcome and other CVD risk factors, except the circulating nitric oxide being decreased by ALM compared to CON. Among 27 of 33 patients with the baseline HbA1c ≤8, ALM decreased post-interventional fasting serum glucose and HbA1c by 5.9% and 3.0% as compared to that of CON, respectively (P = 0.01 and 0.04). Mean total and LDL-cholesterol concentrations were not changed by both diets.ConclusionsThese results suggest almonds incorporated into healthful diets can improve glycemic status in diabetic patients with a better glycemic control.Trial registration NCT01656850, registered 13 January 2012.

The purpose of the current study was to investigate aspects of improved bioenergetic function using nicotinamide during stroke. Using a global ischemia-reperfusion mouse model, ATP was depleted by 50% in the brain. The use of nicotinamide to provide a large reserve of brain NAD⁺ restored ATP levels to 61% of control levels. Alternatively, using nicotinamide as a PARP inhibitor restored ATP levels up to 72%. However, using a large reserve of NAD⁺ in the brain together with PARP inhibition proved to be additive, restoring ATP to 85% of control levels during the first critical 5 min of reperfusion. NAD⁺ and ATP levels correlated almost exactly. Brain mitochondrial function was also examined after cerebral ischemia-reperfusion. State 3 respiration of complex I was found to be abolished. However, this was a non-permanent inhibition of activity in vitro, since (NADH ubiquinone oxideroductase) complex I activity in these mitochondria was restored upon the addition of NADH. In vivo, the use of increased brain NAD⁺ and PARP inhibition was able to partially restore mitochondrial respiration. Taken together, the results show that nicotinamide offers a substantial protective role in terms of preservation of cellular ATP and mitochondrial NAD-linked respiration.

Taiwanese women may practice traditional confinement after childbirth, and no study has investigated the nutritional status and the effects of postpartum depression on such women. The aim of this study was to investigate the association between nutritional status and postpartum depression at 6–8 weeks postpartum. A cross-sectional study was conducted on postpartum women who returned to the obstetrics and gynecology clinic for routine examination from January 2016 to September 2017. A total of 344 women received assessments based on the Edinburgh Postnatal Depression Scale (EPDS). An EPDS score of ≥10 indicated the presence of postpartum depressive symptoms (PPDS). A total of 97 women without such symptoms and 23 with PPDS completed nutritional parameter analyses and questionnaires. The results showed that the prevalence of postpartum depression (PPD) was 8.4%. The proportion was 70% for those who practiced confinement at home, significantly higher than for those in the non-PPDS group (45%). The overall psychological stress score was significantly higher and the postpartum care satisfaction score was significantly lower in those with PPDS compared to those without. In terms of nutritional biomarkers, the plasma riboflavin levels in the PPDS group were significantly lower than those in their symptomless counterparts (13.9%). The vitamin D insufficiency and deficiency rates in the non-PPD and PPDS groups were 35%, 41%, 48%, 26%, respectively. However, compared with those in the non-PPDS group, those with PPDS had significantly higher ratios of Σn-6/Σn-3, C20:3n-6/C18:3n-6, and C20:4n-6/(C20:5n-3 + C22:6n-3) (by 8.2%, 79.7%, and 8.8%, respectively), whereas they had lower ratios of C22:6n-3/C22:5n-6 (by 15.5%). Higher plasma riboflavin and erythrocyte C16:1n-9, C24:1n-9, C18:3n-6, and C20:5n-3 levels and lower Σn-6 fatty acid and C22:5n-6 levels decreased the risk of PPD after type of confinement, overall mental stress scores, and postpartum care satisfaction scores were adjusted for the logistic regression analysis. In conclusion, the plasma riboflavin level and erythrocyte fatty acid composition are potentially major contributors to PPD development.

The development and activation of MHC class II (MHC-II)-restricted CD4 T cells are distinct immunological processes that are strictly MHC-II-dependent. To address their relative dependence on MHC-II, we established a novel ENU-induced mutant mouse on the C57BL/6 background, named I-A, with ∼8-fold reduced I-A expression on the surface of B cells, dendritic cells, cortical thymic epithelial cells, and medullary thymic epithelial cells. I-A and I-A mice are highly similar with respect to the numbers of double-positive thymocytes, CD4CD8 T cells, regulatory T cells, CD4 T cell marker expression, lifespan, and Th/regulatory T cell function. Despite the demonstration of functional intrathymic negative selection in I-A mice, transfer of I-A CD25CD4 T cells into RAG-knockout hosts revealed increased autoaggression activity against the liver. Compared to I-A mice, infection of I-A mice with graded doses of or influenza virus revealed comparable and significantly reduced generation of Ag-specific CD4 T cells at high and low infection doses, respectively. A significantly weakened Ag-specific recall cytokine production response was also found for I-A mice previously infected with a relative low dose of CD44CD4 T cells from I-A and I-A mice previously infected with a relatively high dose displayed highly similar Ag-specific multicytokine production profiles. In contrast, polyclonal activation of endogenous memory-like I-A CD44CD4 T cells revealed highly elevated production of multiple cytokines. Our results demonstrate that there exist distinct thresholds for different MHC-II-dependent immunological processes. The I-A mutant mouse model we describe in the present study is a valuable tool for investigations on the quantitative cause-effect relationship in MHC-II-dependent normal and autoimmune responses.