All-trans-retinoic acid modulates nitric oxide and interleukin-17A production by peripheral blood mononuclear cells from patients with Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD), the most common form of dementia in the elderly, is a neurodegenerative disorder associated with a complex pathophysiology. It is accepted that inflammation contributes to the pathogenesis of AD. All-trans-retinoic acid (ATRA) is a bioactive derivative of vitamin A that has shown immunomodulatory effects in many immune disorders. OBJECTIVES: In our study, we aimed to investigate in vitro immunomodulatory effects of ATRA on inducible nitric oxide synthase (iNOS) expression and interleukin-17A production during AD. METHODS: Peripheral blood mononuclear cells (PBMCs) isolated from 30 Algerian AD patients and 14 age-matched nondemented controls were treated (or not) with ATRA. Production of NO and IL-17A in culture media was measured by the modified Griess method and enzyme-linked immunosorbent assay, respectively. Expression of iNOS in PBMCs was examined by fluorescence immunostaining. RESULTS: Our results showed higher spontaneous in vitro production of NO related to overexpression of iNOS in AD patients compared to controls. Remarkably, ATRA treatment showed an important downregulatory effect on NO production and iNOS expression in patients. This effect was associated with a reduction in IL-17A production and increased IL-10 release. CONCLUSIONS: Taken together, our results indicate that ATRA exerts anti-inflammatory effects in AD. Furthermore, ATRA represents a promising tool for monitoring inflammatory responses associated with disease progression.

Multicenter transversal two-phase study to determine a national prevalence of epilepsy in Algeria.

BACKGROUND/AIMS: The prevalence of epilepsy in Algeria is unknown. The aims of this multicenter transversal study were to determine the national prevalence and clinical characteristics of epilepsy in the Algerian population. METHODS: This two-phase study was conducted in 5 circumscriptions and included 8,046 subjects aged over 2 months who attended the randomly selected public and private primary care clinics. In the phase 1 study, a questionnaire was submitted to the sample of patients. In the phase 2 study, all potentially epileptic people were examined by neurologists and a second questionnaire was submitted, eventually assessed by appropriate investigations. RESULTS: Sixty-seven patients were identified as having active epilepsy, giving a crude prevalence ratio of 8.32 per 1,000 (95% CI, 6.34-10.3) and an age-adjusted prevalence ratio of 8.9 per 1,000. The highest age-specific ratio was found in patients aged 10-19 years (16.92 per 1,000). Generalized seizures (68.7%) were more common than partial seizures (29.8%). Perinatal injuries were the major leading putative causes (11.9%). CONCLUSION: The prevalence of epilepsy of 8.32 determined in this study is relatively high. These results provide new epidemiological data and suggest that epilepsy remains an important public health issue to consider in Algeria.

Mutations in SPG11 are frequent in autosomal recessive spastic paraplegia with thin corpus callosum, cognitive decline and lower motor neuron degeneration.

Hereditary spastic paraplegias (HSP) are neurodegenerative diseases mainly characterized by lower limb spasticity associated, in complicated forms, with additional neurological signs. We have analysed a large series of index patients (n = 76) with this condition, either from families with an autosomal recessive inheritance (n = 43) or isolated patients (n = 33), for mutations in the recently identified SPG11 gene. We found 22 truncating mutations, including the first four splice-site mutations, segregating in seven isolated cases and 13 families. Nineteen mutations were novel. Two recurrent mutations were found in Portuguese and North-African patients indicating founder effects in these populations. The mutation frequency varied according to the phenotype, from 41%, in HSP patients presenting with a thin corpus callosum (TCC) visualized by MRI, to 4.5%, in patients with mental impairment without a TCC. Disease onset occurred during the first to the third decade mainly by problems with gait and/or mental retardation. After a mean disease duration of 14.9 +/- 6.6 years, the phenotype of 38 SPG11 patients was severe with 53% of patients wheelchair bound or bedridden. In addition to mental retardation, 80% of the patients showed cognitive decline with executive dysfunction. Interestingly, the phenotype also frequently included lower motor neuron degeneration (81%) with wasting (53%). Slight ocular cerebellar signs were also noted in patients with long disease durations. In addition to a TCC (95%), brain MRI revealed white matter alterations (69%) and cortical atrophy (81%), which worsened with disease duration. In conclusion, our study reveals the high frequency of SPG11 mutations in patients with HSP, a TCC and cognitive impairment, including in isolated patients, and extends the associated phenotype.

IFN-γ and TNF-α are involved during Alzheimer disease progression and correlate with nitric oxide production: a study in Algerian patients.

Alzheimer's disease (AD) is a neurodegenerative disease leading to a progressive and irreversible loss of mental functions. It is characterized by 3 stages according to the evolution and the severity of the symptoms. This disease is associated with an immune disorder, which appears with significant rise in the inflammatory cytokines and increased production of free radicals such as nitric oxide (NO). Our study aims to investigate interferon (IFN)-γ and tumor necrosis factor-α (TNF-α) involvement in NO production, in vivo and ex vivo, in peripheral blood mononuclear cells from Algerian patients (n=25), according to the different stages of the disease (mild Alzheimer's, moderate Alzheimer's, and severe Alzheimer's) in comparison to mild cognitive impairment (MCI) patients. Interestingly, we observed that in vivo IFN-γ and TNF-α levels assessed in patients with AD in mild and severe stages, respectively, are higher than those observed in patients with moderate stage and MCI. Our in vivo and ex vivo results show that NO production is related to the increased levels of IFN-γ and TNF-α, in mild and severe stages of AD. Remarkably, significant IFN-γ level is only detected in mild stage of AD. Our study suggests that NO production is IFN-γ dependent both in MCI and mild Alzheimer's patients. Further, high levels of NO are associated with an elevation of TNF-α levels in severe stage of AD. Collectively, our data indicate that the proinflammatory cytokine production seems, in part, to be involved in neurological deleterious effects observed during the development of AD through NO pathway.

LRRK2 G2019S mutation in Parkinson's disease: a neuropsychological and neuropsychiatric study in a large Algerian cohort.

A series of 106 patients with isolated or familial Parkinsonism underwent clinical evaluation and genetic testing for the LRRK2 G2019S mutation which was identified in 34/106 patients (32%). Seventy one of them accepted to be evaluated for neuropsychological and neuropsychiatric studies with the aim to compare mutation carriers with non-carriers. For neuropsychological testing, comparisons between LRRK2 G2019S carriers and non-carriers were made after stratification according to the level of education: median and high school versus low level. Memory was investigated with the five words test, 2 novel tests with verbalized visual material dedicated to illiterate patients, the TNI-93 (nine pictures test), The TMA-93 (associative memory test), and digit spans (forward/backward). Cognitive analyse did not show major differences between the two groups of patients. Nevertheless, behavioral abnormalities, mostly depression and hallucinations, were more frequent in the LRRK2 G2019S carriers, suggesting the presence of a greater involvement of the limbic system in these patients. Sleep disorders which were also more common amongst mutation carriers than non-carriers might be related to depression.