Genetic study of spinocerebellar hereditary degenerations in Tunisia. Role of consanguinity in their occurrence

The genetic analysis of 101 genealogical trees of families with spinocerebellar heredo-degeneration enabled the authors to specify the transmission inheritance for each clinical type. Autosomic recessive transmission has been observed for Friedreich's ataxia (68 out of 69 families), Pierre-Marie's heredo-ataxia (15 families) and familial spastic paraplegia (2 families). A dominant mode of transmission has been observed in 13 families affected by familial spastic paraplegia (Strumpell-Lorrain) and in only one family with Friedreich's ataxia (an intermediate or incomplete form). It has also been observed that the consanguinity rate among this group of families is very high compared with that of the general tunisian population (25%). Marriage between cousins occurs in 75% of the cases of Friedreich's ataxia, in 78% of the cases of Pierre-Marie's heredo-ataxia and in only 61% of familial spastic paraplegia of Strumpell-Lorrain. The authors have come to the conclusion that the recessive autosomic transmission of the spino-cerebellar heredo-degenerative diseases are closely related to a high consanguinity rate.     

A new antimicrobial peptide isolated from Oudneya africana seeds

Oudneya africana R. Br. (Brassicaceae), a wild‐growing plant in the arid region of Tunisia, is used in ethno‐medicinal treatment of microbial infections. Validation of ethno‐therapeutic claims pertaining to the plant was sought by investigating its antimicrobial activity. A proteinaceous extract of the seeds, called AS‐3000, showed activity against various organisms including L. monocytogenes, E. coli, B. subtilis, E. hirae, P. aeruginosa, S. aureus and C. albicans. Extract AS‐3000 exhibited a synergistic effect against L. ivanovii when combined with vancomycin or chloramphenicol. The post‐antibiotic inhibitory effect of the ampicillin/AS‐3000 combination was 2.3‐fold greater than for the antibiotic alone. The mode of action of AS‐3000 on Listeria and Escherichia was visible using SEM. These results support the use of O. africana for treating microbial infections.     

Therapeutic properties and molecular docking study of some phenolic compounds as anti-human lung cancer potential: A biochemical approach

Chloroxine (5,7-dichloro-8-hydroxyquinoline) is a molecule utilized in some shampoos for the therapy of seborrheic dermatitis of the scalp and dandruff. In this study, we investigated the inhibition effects of 5,7-dichloro-8-hydroxyquinoline and methyl 3,4,5-trihydroxybenzoate compounds on the 3-hydroxy-3-methylglutaryl coenzyme-A (HMG-CoA Reductase) and urease enzymes. We have obtained results for the HMG-CoA Reductase and urease enzymes at the micromolar level. In our study, inhibition result of 5,7-dichloro-8-hydroxyquinoline and Methyl 3,4,5-trihydroxybenzoate on HMG-CoA reductase showed lower values 2.28 ± 0.78 and 33.25 ± 5.04 µg/ml, respectively. Additionally, inhibition result of 5,7-dichloro-8-hydroxyquinoline and methyl 3,4,5-trihydroxybenzoate on urease showed lower values 6.18 ± 1.38 and 8.51 ± 1.35 µg/ml, respectively. Molecular docking calculations were made for their biological activities were compared. In the present work, the structures of the related compounds ( 1 and 2 ) were drawn using Gaussian 09 software and done geometry optimization at DFT/B3LYP/6-31G* basis set with aforementioned program. Cytotoxicity potential of these compounds against human lung cancer demonstrated that these compounds had good cytotoxic effects. Both compounds significantly decreased lung cell viability from low doses. In addition, 100 µM dose of all compounds caused significant reductions in lung cell viability. In general, we can say that of the two tested compounds, 5,7-dichloro-8-hydroxyquinoline and methyl 3,4,5-trihydroxybenzoate have cytotoxic effects in all cell types, and this effect is particularly strong in lung cells. Activities were performed at concentrations of 10, 20, 50, 70, and 100 µl and we achieved good results. Lung cell viability (%) value was better at 100 µl concentration and IC₅₀ of them were 54.28 and 48.05 µM.     

Global soil nitrogen cycle pattern and nitrogen enrichment effects: Tropical versus subtropical forests

Tropical and subtropical forest biomes are a main hotspot for the global nitrogen (N) cycle. Yet, our understanding of global soil N cycle patterns and drivers and their response to N deposition in these biomes remains elusive. By a meta-analysis of 2426-single and 161-paired observations from 89 published ¹⁵ N pool dilution and tracing studies, we found that gross N mineralization (GNM), immobilization of ammonium ($I_{{\mathrm{NH}}_4}$) and nitrate ($I_{{\mathrm{NO}}_3}$), and dissimilatory nitrate reduction to ammonium (DNRA) were significantly higher in tropical forests than in subtropical forests. Soil N cycle was conservative in tropical forests with ratios of gross nitrification (GN) to $I_{{\mathrm{NH}}_4}$ (GN/$I_{{\mathrm{NH}}_4}$) and of soil nitrate to ammonium (NO₃⁻/NH₄⁺) less than one, but was leaky in subtropical forests with GN/$I_{{\mathrm{NH}}_4}$ and NO₃⁻/NH₄⁺ higher than one. Soil NH₄⁺ dynamics were mainly controlled by soil substrate (e.g., total N), but climatic factors (e.g., precipitation and/or temperature) were more important in controlling soil NO₃⁻ dynamics. Soil texture played a role, as GNM and $I_{{\mathrm{NH}}_4}$ were positively correlated with silt and clay contents, while $I_{{\mathrm{NO}}_3}$ and DNRA were positively correlated with sand and clay contents, respectively. The soil N cycle was more sensitive to N deposition in tropical forests than in subtropical forests. Nitrogen deposition leads to a leaky N cycle in tropical forests, as evidenced by the increase in GN/$I_{{\mathrm{NH}}_4}$, NO₃⁻/NH₄⁺, and nitrous oxide emissions and the decrease in $I_{{\mathrm{NO}}_3}$ and DNRA, mainly due to the decrease in soil microbial biomass and pH. Dominant tree species can also influence soil N cycle pattern, which has changed from conservative in deciduous forests to leaky in coniferous forests. We provide global evidence that tropical, but not subtropical, forests are characterized by soil N dynamics sustaining N availability and that N deposition inhibits soil N retention and stimulates N losses in these biomes.     

SciDBMaker: new software for computer-aided design of specialized biological databases

Background  

The exponential growth of research in molecular biology has brought concomitant proliferation of databases for stocking its findings. A variety of protein sequence databases exist. While all of these strive for completeness, the range of user interests is often beyond their scope. Large databases covering a broad range of domains tend to offer less detailed information than smaller, more specialized resources, often creating a need to combine data from many sources in order to obtain a complete picture. Scientific researchers are continually developing new specific databases to enhance their understanding of biological processes.     

Moderate walnut consumption improved lipid profile,steroid hormones and inflammation in trained elderly men: a pilot study with a randomized controlled trial

The present study aimed to investigate the effect of walnut consumption on lipid profile, steroid hormones and inflammation in trained elderly men performing concurrent (resistance and endurance) training. Twenty healthy elderly males were divided into two matched groups, in a randomized controlled trial, that trained three sessions per week: concurrent training + dietary walnut consumption (15 g/day for six weeks, CTW: n = 10); concurrent training + control diet (CT: n = 10). Fasting blood samples were taken 48 hours before and after intervention for biochemical assessments. levels of high-density lipoprotein (HDL) increased only in CTW compared to baseline (19.8%, p < 0.01). Total cholesterol (TC), low-density lipoprotein (LDL) and triglyceride (TG) levels significantly decreased only for CTW (i.e., 13%, 18%, and 18.5% at p < 0.01 for all). Testosterone (T) increased after the training compared to pre-training for CTW and CT (10.3%, p < 0.01, 4.27% p < 0.05, respectively), but the increase was significantly higher in CTW (p < 0.05). Serum cortisol (C) was lower for CTW compared to CT (p < 0.01). C-reactive protein (CRP) decreased in CTW in comparison with CT. The present study revealed that 6-week moderate walnut supplementation (15 g/day) improved lipid profile, steroid hormones and systematic inflammation in aged men performing concurrent training. These findings could be attributable to the potential effect of polyunsaturated fatty acids (PUFA) contained in walnut (linoleic acid, n-6; linolenic acid, n-3).     

Recessive Schwartz-Jampel syndrome (SJS): confirmation of linkage to chromosome 1p,evidence of genetic homogeneity and reduction of the SJS locus to a 3-cM interval

Schwartz-Jampel syndrome (SJS), or chondrodystrophic myotonia, is a rare autosomal recessive disorder characterized by generalized myotonia resulting in a particular, recognizable facies and osteoarticular abnormalities. Some of us have recently shown genetic linkage of SJS to a locus on 1p34–p36.1 in five families. Here, we show by homozygosity mapping and segregation analysis that eight new families are most likely linked to the SJS locus on chromosome 1, confirming the localization of SJS to chromosome 1p and suggesting genetic homogeneity. Recombination events reduced the SJS locus from a genetic interval of 8 to 3 cM, which should facilitate the identification of the SJS gene. Low clinical variability was observed between the studied families, except for osteoarticular abnormalities. Since the severity and the location of osteoarticular abnormalities varied from one individual to another, even in the same families, other factors than the SJS gene itself, genetic or epigenetic, might contribute to the phenotype. Received: 11 February 1996 / Revised: 6 April 1996