Melatonin reduces nitric oxide synthase activity in rat hypothalamus

Abstract: In this report, rat hypothalamic nitric oxide synthase (NOS) activity is shown to be partially inhibited by physiological concentrations of the pineal hormone melatonin. In vitro studies demonstrate that 1 nM melatonin, which approximates the physiological concentration of the hormone at night, significantly inhibited NOS activity. In vivo studies show that administering melatonin or collecting the hypothalamus from animals at night, when endogenous melatonin levels are elevated, results in a significant decrease of NOS activity. Results also show that calmodulin may be involved in this process since its presence in the incubation medium prevents the inhibitory effect of melatonin on NOS activity.     

Novel Mutations in the Amyloid Precursor Protein Gene within Moroccan Patients with Alzheimer's Disease

In Morocco, Alzheimer's disease (AD) affects almost 30,000 individuals, and this number could increase to 75,000 by 2020. To our knowledge, the genes predisposing individuals to AD and predicting disease incidence remain elusive. In this study, we aimed to evaluate the genetic contribution of mutations in the amyloid precursor protein (APP) gene exons 16 and 17 to familial and sporadic AD cases. Seventeen sporadic cases and eight family cases were seen at the memory clinic of the University of Casablanca Neurology Department. These patients underwent standard somatic neurological examination, cognitive function assessment, brain imaging, and laboratory tests. Direct sequencing of exons 16 and 17 of the APP gene was performed on genomic DNA of AD patients. In this original Moroccan study, we identified seven novel frameshift mutations in exons 16 and 17 of the APP gene. Interestingly, only one novel splice mutation was detected in a family case. There is a strong correlation between clinical symptoms and genetic factors in Moroccan patients with a family history of AD. Therefore, mutations in APP gene exons 16 and 17 may eventually become genetic markers for AD predisposition.     

Correction to: Rarely occurring mutation of ACVR1 gene in Moroccan patient with fibrodysplasia ossificans progressiva

Clinical Rheumatology - One of the author’s name on this article was incorrectly spelled as “Renata Borcciadi”. The correct spelling is “Renata Bocciardi” and is now...     

Fungicidal Mechanisms of Cathelicidins LL-37 and CATH-2 Revealed by Live-Cell Imaging

Antifungal mechanisms of action of two cathelicidins, chicken CATH-2 and human LL-37, were studied and compared with the mode of action of the salivary peptide histatin 5 (Hst5). Candida albicans was used as a model organism for fungal pathogens. Analysis by live-cell imaging showed that the peptides kill C. albicans rapidly. CATH-2 is the most active peptide and kills C. albicans within 5 min. Both cathelicidins induce cell membrane permeabilization and simultaneous vacuolar expansion. Minimal fungicidal concentrations (MFC) are in the same order of magnitude for all three peptides, but the mechanisms of antifungal activity are very different. The activity of cathelicidins is independent of the energy status of the fungal cell, unlike Hst5 activity. Live-cell imaging using fluorescently labeled peptides showed that both CATH-2 and LL-37 quickly localize to the C. albicans cell membrane, while Hst5 was mainly directed to the fungal vacuole. Small amounts of cathelicidins internalize at sub-MFCs, suggesting that intracellular activities of the peptide could contribute to the antifungal activity. Analysis by flow cytometry indicated that CATH-2 significantly decreases C. albicans cell size. Finally, electron microscopy showed that CATH-2 affects the integrity of the cell membrane and nuclear envelope. It is concluded that the general mechanisms of action of both cathelicidins are partially similar (but very different from that of Hst5). CATH-2 has unique features and possesses antifungal potential superior to that of LL-37.     

Albuminuria in type 2 diabetes mellitus: from remission to progression

Objective Albuminuria is an early marker of renal impairment and a powerful factor of progression of renal disease in type 2 diabetes (T2D). Approximately, one-third of patients with T2D have micro- or macroalbuminuria and these patients have a high risk of progression toward End Stage Renal Disease (ESRD) as well as increased cardiovascular disease. The aim of this study was to determine the prevalence of remission, regression, persistence, and progression of albuminuria, and to evaluate the impact of change in albuminuria on kidney disease and cardiovascular disease in a prospective cohort of patients with T2D. Methods This is a prospective study. The Ethics Committee of Morocco’s Mohammed V University in Rabat approved the study protocol. Inclusion criteria targeted patients who were type 2 diabetics with albuminuria?>30?mg/day, and who had been regularly followed-up in nephrology consultation for at least 36 months. Results Five-hundred twenty-four patients were included. 75.8 and 24.6% of all patients had micro- and macroalbuminuria at enrollment in the study. At the end of the study, 91, 141, 199, and 93 patients had remission, regression, persistence, and progression of albuminuria, respectively. Remission of microalbuminuria to normoalbuminuria was observed in 23.6% of cases. Regression of macroalbuminuria to micro- was observed in 29.9% of cases. Conclusion In our study, the incidence of remission and/or regression of micro- and macroalbuminuria was higher. The incidence of ESRD and the occurrence of cardiac events were greater in the regression, persistence, and progression groups than in the remission of albuminuria group.