Apolipoprotein E Genotypes in Alzheimer's Disease in Central Algerian Population

Background: Alzheimer's disease (AD) is a progressive and fatal neurodegenerative disorder associated with cognitive decline and is the most common form of dementia in the elderly. Early-onset familial AD accounts for less than 1% of AD cases and develops before the age of 65 years because of mutations in either the APP gene or genes encoding presenilin 1 (PSEN1) or presenilin 2 (PSEN2). The majority of sporadic AD cases are referred to as late-onset AD (LOAD) because they occur late in life (>65 years). Apolipoprotein E (APOE) polymorphic alleles are the major genetic risk factor for AD. The human APOE gene exists as three polymorphic alleles, ε2, ε3, and ε4, with a worldwide frequency of 8%, 78%, and 13%, respectively, with ε4 reaching frequencies of 40% in AD patients. The purpose of this preliminary study was to determine ApoE genotype status since no previous association studies between LOAD and ApoE gene were available for the Central Algerian population. Methods: The cohort of our study was composed of 47 AD patients recruited from the Neurology Department of Frantz Fanon Hospital of Blida. Forty-seven controls with no type of dementia were also included in the study. All samples were genotyped for the ApoE Polymorphisms by PCR-RFLP method. Statistical studies can use the Fisher exact test or Chi-2 using the GraphPad Prism 7.0 software. Results: The results show that the genotype ɛ3/ɛ3 is most common in both groups followed by the heterozygous genotype ɛ3/ɛ4 which showed an increased frequency in patients compared to controls (27.66% vs. 12.77%, OR=3.66, IC=0.89-7.9, p=0,11). Although rare, all other possible genotypes have been observed in our cohort, namely ɛ2/ɛ2, ɛ2/ɛ3, ɛ2/ɛ4 and ɛ4/ɛ4. The ɛ2/ɛ4 genotype was observed only in AD patients, while the ɛ2/ɛ2 genotype was observed only in controls. As expected, the homozygous genotype ɛ4/ɛ4 was more frequent in AD patients, compared to controls (6.38% vs. 2.13%, respectively OR=2.64, IC=0.36-37.33; p=0,33). At the allelic level, ɛ4 allele was significantly associated with AD compared to controls (21,28% vs. 4,26% ; OR= 2.75, 95% CI= 1.109-6.35; p = 0.02, respectively), while the ɛ2 allele seems to be protective (4,26% vs. 9,57%, OR = 0.49 ; 95% CI=0.14-1.66 ; p=0,38, respectively), but without statistical significance. In population-based studies, the ApoEɛ4-AD association was weaker among African Americans (ε4/ε4, OR 5.7) and Hispanics (ε4/ε4, OR 2.2) and was stronger in the Japanese population (ε4/ε4, OR 33.1) compared with Caucasian cases (ε4/ε4, OR 12.5). The results obtained in our preliminary study indicate that the ApoEɛ4-AD association in the Central Algerian population is similar to that observed in the Mediterranean populations. Conclusion: We have presented, for the first time in the North Central Algerian population, the association of the ɛ4 allele with AD, which could be of great use in the diagnosis but also the follow-up of patients with this disease

EVALUATION DES INDICES D'ALTERATION CHIMIQUE SUR UN PROFIL KAOLINISE CAS : TAMAZERT (NE ALGERIE) ASSESSMENT OF CHEMICAL WEATHERING INDICES IN KAOLINISED PROFIL CASE: TAMAZERT (NE ALGERIA)

peer reviewedLes indices d'altération chimique sont couramment utilisés pour caractériser les profils d'altération développés sur des roches mères hétérogènes ou homogènes. Parmi les indices d'altération évalués dans cette étude, l'indice de Parker (WIP), l'indice chimique d'altération (CIA), l'indice de météorisation chimique (CIW), l'indice d'altération des plagioclases (PIA), Ruxton ratio (R). L'objectif principal de cette étude est d'examiné l'étendue de l'altération chimique affectée les différentes roches surtout gneissiques dans la zone de Tamazert et de tester l'aptitude d'application des indices d'altération chimique pour des profils d'altération hétérogènes. La pétrographie et la géochimie des éléments majeurs de la roche mère et du produit d'altération ont été discuté dans ce travail

EVALUATION DES INDICES D’ALTERATION CHIMIQUE SUR UN PROFIL KAOLINISE CAS : TAMAZERT (NE ALGERIE)

Chemical weathering indices are commonly used for characterizing weathering profiles developed on heterogeneous or homogeneous parent rock by incorporating bulk major element oxide chemistry into single metric of each sample. Chemical weathering indices evaluated in this study are: weathering index of Parker (WIP), the chemical index of alteration (CIA), chemical index of weathering (CIW), plagioclase index of alteration (PIA), Ruxton ratio (R). The main purpose of this study is to review the scope of chemical weathering affected different gneissic rocks especially in Tamazert area and test the ability of application of chemical weathering index for heterogeneous alteration profiles. Petrology and geochemistry of the major elements of rock and alteration product have been discussed in this work.Les indices d’altération chimique sont couramment utilisés pour caractériser les profils d’altération développés sur des roches mères hétérogènes ou homogènes. Parmi les indices d’altération évalués dans cette étude, l’indice de Parker (WIP), l’indice chimique d’altération (CIA), l’indice de météorisation chimique (CIW), l’indice d’altération des plagioclases (PIA), Ruxton ratio (R). L’objectif principal de cette étude est d'examiné l'étendue de l'altération chimique affectée les différentes roches surtout gneissiques dans la zone de Tamazert et de tester l’aptitude d’application des indices d’altération chimique pour des profils d’altération hétérogènes. La pétrographie et la géochimie des éléments majeurs de la roche mère et du produit d’altération ont été discuté dans ce travail

Characterization of the inflammatory cell infiltrate and expression of costimulatory molecules in chronic echinococcus granulosus infection of the human liver

Background: The local immune responses to chronic echinococcal infections in various organs are largely unknown. Since the liver is the most frequently involved organ in such infections in human we aimed to characterize the inflammatory as well as immune cell infiltrate around hydatid cysts in the liver and compared to common inflammatory processes of the liver. Method: Surgical samples from the liver of 21 cystic echinococcosis (CE) patients were studied and the distribution of different types of inflammatory and immune cells were determined by immunohistochemistry. Furthermore, expression levels of costimulatory CTLA4, CD28, CD80 and CD86 molecules were measured at RNA level by PCR. Liver biopsy samples from patients with steatohepatitis (SH, n = 11) and chronic hepatitis (CH, n = 11) were used as non-inflammatory and chronic inflammatory controls, respectively. The composition and density of the inflammatory and immune cell infiltrates have been compared by using morphometry. Results: CD3+ T cells predominated the inflammatory infiltrate in all pathological processes, while in CE samples CD20+ B cells, in CH samples CD68+ macrophages were also frequent. Both myeloperoxidase (MPO) + leukocytes and CD68+ macrophages were found to be significantly decreased in CE as compared to either SH or CH samples. Concerning T cell subtypes, only CD8+ T cells were found to be significantly decreased in SH samples. CD1a + dendritic cells were almost completely missing from CE biopsies unlike in any other sample types. There were no differences detected in the mRNA expression of costimulatory molecules except decreased expression of CD28 in CE samples. Conclusion: In the hydatid lesions of the liver of chronic echinococcal infections T cell-mediated immunity seems to be impaired as compared to other types of chronic inflammatory processes, suggesting an immunosuppressive role for Echinococcus granulosus, which deserve further attentions