Rivastigmine-Benzimidazole Hybrids as Promising Multitarget Metal-Modulating Compounds for Potential Treatment of Neurodegenerative Diseases

With the goal of combating the multi-faceted Alzheimer's disease (AD), a series of Rivastigmine-Benzimidazole (RIV-BIM) hybrids was recently reported by us as multitarget-directed ligands, thanks to their capacity to tackle important hallmarks of AD. In particular, they exhibited antioxidant activity, acted as cholinesterase inhibitors, and inhibited amyloid-β (Aβ) aggregation. Herein, we moved forward in this project, studying their ability to chelate redox-active biometal ions, Cu(II) and Fe(III), with widely recognized roles in the generation of oxidative reactive species and in protein misfolding and aggregation in both AD and Parkinson's disease (PD). Although Cu(II) chelation showed higher efficiency for the positional isomers of series 5 than those of series 4 of the hybrids, the Aβ-aggregation inhibition appears more dependent on their capacity for fibril intercalation than on copper chelation. Since monoamine oxidases (MAOs) are also important targets for the treatment of AD and PD, the capacity of these hybrids to inhibit MAO-A and MAO-B was evaluated, and they showed higher activity and selectivity for MAO-A. The rationalization of the experimental evaluations (metal chelation and MAO inhibition) was supported by computational molecular modeling studies. Finally, some compounds showed also neuroprotective effects in human neuroblastoma (SH-SY5Y cells) upon treatment with 1-methyl-4-phenylpyridinium (MPP⁺), a neurotoxic metabolite of a Parkinsonian-inducing agent.

LPS-induced mitochondrial dysfunction regulates innate immunity activation and α-synuclein oligomerization in Parkinson's disease

Sporadic Parkinson's disease (sPD) is a complex multifactorial disorder which etiology remains elusive. Several mechanisms have been described to contribute to PD development namely mitochondrial dysfunction, activation of inflammatory pathways and the deposition of unfolded proteins such as α-synuclein. Our work shows for the first time that lipopolysaccharide (LPS)-induced activation of innate immunity requires a functional mitochondria and mimics PD pathology in cells. We found in primary mesencephalic neurons that LPS targeted the mitochondria and activated neuronal innate immune responses, which culminated with α-synuclein oligomerization. Moreover, in cybrid cell lines repopulated with mtDNA from sPD subjects with inherent mitochondrial dysfunction and NT2-Rho0 obtained by long-term ethidium bromide exposure, and so without a functional mitochondrial, LPS was not able to further activate innate immunity or increase α-synuclein aggregation. Herein, we showed that mesencephalic neurons are able to activate innate immunity after LPS exposure and this pathway is dependent on mitochondria. Moreover, we disclose that α-synuclein over production is an innate immune response. Our data indicate that mitochondria provide the base for innate immunity activation in idiopathic PD.

Prognostic significance of specific EEG patterns after cardiac arrest in a Lisbon Cohort

Objective

To evaluate if EEG patterns considered highly malignant are reliable predictors not only of poor neurological outcome but also reliable predictors of death.

Methods

Retrospectively, EEGs from Cardiac Arrest (CA) patients of two teaching hospitals in Lisbon were classified into 3 groups: highly malignant, malignant, and benign groups. Outcome was assessed at 6 months after CA by CPC (Cerebral Performance Categories) scale. We evaluated the accuracy of these patterns to predict poor neurological outcome and death.

Results

We included 106 patients for analysis. All patients with a highly malignant EEG (n = 37) presented a poor neurological outcome. Those patterns were also associated with death. Malignant EEG patterns were not associated with poor neurological outcome. Benign EEG patterns were associated with good neurological recovery (p < 0.0001).

Conclusion

Highly malignant EEG patterns were strongly associated with poor neurological outcome and can be considered to be predictors of death.

Significance

This study increased the knowledge about the value of EEG as a tool in outcome prediction of patients after cardiac arrest.

Meconium aspiration syndrome - the experience of a tertiary center

BACKGROUND

Approximately 5 % of infants born with a meconium-stained amniotic fluid (MSAF) develop meconium aspiration syndrome (MAS).

AIM

The aims of this study were to analyse demographic data, morbidity and mortality associated with MAS and to identify possible risk factors.

METHODS

Retrospective chart review of newborns with MAS delivered at a tertiary centre from January 1st, 1997 to December 31st, 2008.

RESULTS

MAS was responsible for 1.4 % of all Neonatal Intensive Care Unit (NICU) admissions, with a trend towards a decreasing incidence during the study duration, especially in the cases of thin meconium. Seventy two newborns were analysed during the study period: 55.6 % (n = 40) were of the female gender, 62.5 % were delivered by caesarean section, 93 % had > 36 weeks of gestational age and 91.2 % had a birth weight over 2500g. Sixty-nine percent had an Apgar score < 7 at 1 minute and 23.6 % an Apgar score < 7 at 5 minutes; foetal bradicardia was present in 26.4 % of the newborns and tachycardia in 1.4 %. The presence of meconium was associated with severe asphyxia and carried a bad prognosis with an increased risk of developing hypoxia (58.3 %), need of mechanical ventilatory support (43.1 %), respiratory and/or metabolic acidosis (30.6 %), pulmonary hypertension (11.1 %) and hypoxic ischemic encephalopathy (29.2 %). The mortality rate was 2.8 %. Thick meconium was associated with higher morbidity and mortality rates.

CONCLUSION

The number of admissions for MAS has been decreasing mostly because of a lower admission rate due to thin meconium; the number of cases with thick meconium has remained constant throughout the years. An Apgar score < 7 at 1 minute and signs of foetal distress during labour were associated with MAS. The MAS related morbidity remains significant.

New findings in partial trisomy 16q: clinical report

Partial trisomy 16q is a rare disorder associated with significant dysmorphism, psychomotor retardation and limited postnatal survival. A female infant with a partial trisomy 16q from a de novo translocation 11;16 is described. Clinical findings were consistent with previous reports, with the exceptions of megalocornea, partial callosal agenesis and mild bilateral occipital lobe hypoplasia.

CONCLUSION

Based on this clinical report, megalocornea, partial callosal agenesis and mild bilateral occipital lobe hypoplasia should perhaps be included in the list of anomalies associated with partial trisomy 16q.