Les manifestations hématologiques du lupus érythémateux systémique. A propos de 70 cas dans une série de 80 LES

Abstract

Systemic lupus erythematosus is a non-organ specific auto-immune disease which commonly has haematological manifestations. The aim of this study was to assess the epidemiological aspects of haematological manifestations among 80 patients with systemic lupus erythematosus (SLE).

Methods

A retrospective study of 80 SLE patients covering the period between 1990 and May 2005.

Results

From among the 80 patients with SLE, 70 had haematological manifestations, of which 65 women and 5 men. Average age was 32.41 years. The most commonly-observed haematological manifestation was anaemia (83.75%), followed by bicytopaenia (63.75%) then leukocytopaenia and/or lymphocytopaenia (62.5).     

Leberagin-C,A disintegrin-like/cysteine-rich protein from Macrovipera lebetina transmediterranea venom,inhibits alphavbeta3 integrin-mediated cell adhesion

Leberagin-C, a new member of the disintegrin-like/cysteine-rich (D/C) family, was purified to homogeneity from the venom of Tunisian snake Macrovipera lebetina transmediterranea. It is a monomeric protein with a molecular mass of 25,787 Da. Its complete sequence of 205 amino acid residues was established by cDNA cloning. The leberagin-C shows many conserved sequences with other known D/C proteins, like the SECD binding sites and a pattern of 28 cysteines. It is the first purified protein from M. lebetina transmediterranea with only two disintegrin-like/cysteine-rich domains. Leberagin-C is able to inhibit platelet aggregation induced by thrombin and arachidonic acid with IC₅₀ of 40 and 50 nM respectively. It was also able to inhibit the adhesion of melanoma tumour cells on fibrinogen and fibronectin, by interfering with the function of alphavbeta3 and, to a lesser extent, with alphavbeta6 and alpha5beta1 integrins. To our knowledge, leberagin-C is the sole described D/C protein that does not specifically interact with the alpha2beta1 integrin. Structure–activity relationship study of leberagin-C suggested that there are some important amino acid differences with jararhagin, the most studied PIII metalloprotease from Bothrops jararaca, notably around the SECD motif in its disintegrin-like domain. Other regions implicated in leberagin-C specificities could not be excluded.     

Occurrence of Culicoides spp. (Diptera: Ceratopogonidae) in Tunisia, with emphasis on the bluetongue vector Culicoides imicola

Following the bluetongue (BT) outbreaks in Tunisia from 1999 to 2002, BTV (bluetongue virus) serotype 2 was isolated; however, no entomological investigation was performed. In the study presented here, we assessed the Culicoides species populations (particularly C. imicola) in proximity to the BT outbreaks locations, both as a retrospective analysis and to update the list of Culicoides species present in Tunisia. The insects were caught using light traps and the species identification was performed according to the standard entomological methods. This study reveaaled the presence of significant numbers of C. imicola in all the tested locations. In addition, we reported a new Culicoides species for the Tunisian fauna C. punctatus.     

Maintenance of pathogenicity during entry into and resuscitation from viable but nonculturable state in Aeromonas hydrophila exposed to natural seawater at low temperature

AIMS: To investigate the fate of Aeromonas hydrophila pathogenicity when cells switch, in nutrient-poor filtered sterilized seawater, between the culturable and nonculturable state. METHODS AND RESULTS: Aeromonas hydrophila ATCC 7966, rendered non culturable within 50-55 days of exposure to marine stress conditions, was tested for its ability to maintain haemolysin and to adhere to McCoy cells. Results showed that pathogenicity was lost concomitantly with culturability, whereas cell viability remained undamaged, as determined by the Kogure cell elongation test. However, this loss is only temporary because, following temperature shift from 5 to 23 degrees C, multiple biological activities of recovered Aer. hydrophila cells, which include their ability to lyse human erythrocytes and to attach and destroy McCoy cells were regained. During the temperature-induced resuscitation, constant total cell counts were observed. Moreover, no significant improvement in recovery yield was obtained on brain-heart infusion (BHI) agar plates amended with catalase. We suggest that in addition to the growth of the few undetected culturable cells, there is repair and growth of some mildly injured viable but nonculturable cells. CONCLUSIONS: The possibility that nonculturable cells of normally culturable Aer. hydrophila in natural marine environment may constitute a source of infectious diseases posing a public health problem was demonstrated. SIGNIFICANCE AND IMPACT OF THE STUDY: These experiments may mimic what happens when Aer. hydrophila cells are released in natural seawater with careful attention to the conditions in which surrounding waters gradually become warmer in late summer/early autumn.     

Engineering of a recombinant vitamin K-dependent gamma-carboxylation system with enhanced gamma-carboxyglutamic acid forming capacity: evidence for a functional CXXC redox center in the system

The vitamin K-dependent gamma-carboxylation system in the endoplasmic reticulum membrane responsible for gamma-carboxyglutamic acid modification of vitamin K-dependent proteins includes gamma-carboxylase and vitamin K 2,3-epoxide reductase (VKOR). An understanding of the mechanism by which this system works at the molecular level has been hampered by the difficulty of identifying VKOR involved in warfarin sensitive reduction of vitamin K 2,3-epoxide to reduced vitamin K(1)H(2), the gamma-carboxylase cofactor. Identification and cloning of VKORC1, a proposed subunit of a larger VKOR enzyme complex, have provided opportunities for new experimental approaches aimed at understanding the vitamin K-dependent gamma-carboxylation system. In this work we have engineered stably transfected baby hamster kidney cells containing gamma-carboxylase and VKORC1 cDNA constructs, respectively, and stably double transfected cells with the gamma-carboxylase and the VKORC1 cDNA constructs in a bicistronic vector. All engineered cells showed increased activities of the enzymes encoded by the cDNAs. However increased activity of the gamma-carboxylation system, where VKOR provides the reduced vitamin K(1)H(2) cofactor, was measured only in cells transfected with VKORC1 and the double transfected cells. The results show that VKOR is the rate-limiting step in the gamma-carboxylation system and demonstrate successful engineering of cells containing a recombinant vitamin K-dependent gamma-carboxylation system with enhanced capacity for gamma-carboxyglutamic acid modification. The proposed thioredoxin-like (132)CXXC(135) redox center in VKORC1 was tested by expressing the VKORC1 mutants Cys(132)/Ser and Cys(135)/Ser in BHK cells. Both of the expressed mutant proteins were inactive supporting the existence of a CXXC redox center in VKOR.     

Morphological and genetic characterization of the sharpsnout seabream populations (Diplodus puntazzo,Sparidae) along a boundary area between the two Mediterranean basins

In order to test the potential ecological role of the Siculo-Tunisian Strait as a geographic barrier, the morphological and genetic variation of eight Tunisian samples of the sharpsnout seabream, Diplodus puntazzo, were studied, based on 23 truss network elements and 13 polymorphic allozyme loci. Significant morphological differences were observed between studied samples, especially between lagoon ones. Although genetic data did not support the detected morphometric variation, F-statistics indices (F_IS and F_ST) revealed a significant departure from panmixia with heterozygote deficiencies and slight genetic differentiation between samples. Genetic results suggested the existence of moderate and local genetic heterogeneity that can be explained by the chaotic genetic patchiness hypothesis. Morphological and genetic results showed that the Siculo-Tunisian Strait does not seem to act as a barrier limiting the connectivity between the natural populations of D. puntazzo, at least at the scale of the Tunisian coast. Thus, the phenotypic variation identified in this study appears to be environmentally induced through the exploitation of different ecological niches and hydrodynamic constraints.     

Effects of nitrogen rates on grain yield and nitrogen agronomic efficiency of durum wheat genotypes under different environments

Durum wheat is an important staple food crop in Tunisia and other Mediterranean countries and is grown in various climatic conditions. Production and yield are however severely limited not only by drought events but also by reduced levels of nitrogen fertilisation. A study was carried out at two locations in the sub‐humid area of Tunisia: Mateur in 2009–10 and 2010–11 and Beja in 2011–12 and 2012–13 under rainfed conditions. Four durum wheat genotypes (landraces: Bidi, Azizi; improved: Om Rabia, Khiar) were evaluated for nitrogen agronomic efficiency and related agronomic traits under various nitrogen rates: 0, 50, 100, 150, 200 and 250 kg N ha^?1, with three replications. There was a significant interaction effect (P ≤ 0.001) environments × genotypes × N treatments for grain yield (GY), biomass yield (BY), harvest index (HI), partial factor productivity of applied nitrogen (PFP_N) and nitrogen agronomic use efficiencies (NAE). GY was the most affected trait by nitrogen applied showing an increase of 94% under high N treatment (250 kg N ha^?1) compared to control plots without N treatments. A significant linear regression exists between GY (0 N) and GY for the different N rates (r = 0.70; P < 0.001). This effect was more pronounced for improved genotypes than landraces for all parameters excepting BY and NAE_BY. BY showed +11% increase in landraces than improved genotypes. PFP_N showed an average decrease of 65% under high‐N fertilisation with 10% prevalence for improved genotypes. Landraces tend to promote vegetative growth while grain filling efficiency was higher for improved genotypes.     

Effect of time of day on line-bisecting performance in female soccer players

The purpose of this study was to examine the effect of time of day on visuospatial attention in trained subjects. We used the line-bisecting task. The protocol involved 30 healthy volunteer female soccer players (age: 21.1 ± 2.1 years, level of experience: 8.1 ± 3.2 years, height: 1.7 ± 0.03 cm, weight: 59.2 ± 3.49 kg). They performed two-test sessions at different times of day, 8:00 am and 8:00 pm. The results showed a significant time-of-day effect on line-bisecting performance, with a better precision in the evening than in the morning. The rightward error observed in the morning was reversed in the evening. An interaction between time of day x length was also observed, indicating that the difference in performance between the morning and the evening increased with the length of the line. We conclude that activities that require better visuospatial performance should be programed to take place in the evening.     

Effects of lunar phases on short-term,explosive physical performance among young trained athletes

Beliefs that lunar phases affect human physiology started in ancient times. Research has recently revealed that a physical fitness index increased in sedentary students at the new moon (NM) and full moon (FM) compared to other moon phases. However, the effect of lunar cycle (moon illumination and gravitational pull) on physical performance in athletes was not examined. Therefore, this study aimed to evaluate whether short-term explosive performance can be influenced by the different phases of the lunar cycle. Fourteen young male Taekwondo athletes (age: 16.9 ± 0.7 years, height: 159.7 ± 50.6 cm, body mass: 62.85 ± 7.84 kg) performed the following tests to assess the explosive physical performance during the different phases of the lunar cycle (NM, FQ (first quarter), FM, and LQ (last quarter)): maximal isometric manual contraction (dominant hand (MIMCD) and non-dominant hand (MIMCND)), maximal back isometric contraction (MBIC), squat jump (SJ), countermovement jump (CMJ), and 10-m sprint (10 m). The testing sessions during the different moon phases were performed in a counterbalanced order. The order of tests remained the same (MIMCD, MIMCND, MBIC, SJ, CMJ, and 10 m), and all sessions were performed in the evening (6:00 to 8:00 p.m.) on the first day of each evaluated lunar phase. Each parameter was measured over two consecutive lunar months in the calendar. Analysis of variance tests showed that there was no significant effect of lunar cycle on all explosive test measures, p > 0.05. Our results failed to identify any effect of lunar phase on evening explosive performance (mainly involving phosphagen pathway-based efforts) among young trained athletes. Therefore, it appears that moon phase/illumination does not affect short-term physical performance in young trained adolescents.     

The ability of Silybum marianum to phytoremediate cadmium and/or diesel oil from the soil

Phytoremediation is a new ecological and cost-effective technology applied for cleaning heavy metals and total petroleum hydrocarbon contaminated (TPH-contaminated) soils. This study was conducted to evaluate the potential of milk thistle (Silybum marianum) to phytoremediate cadmium (Cd (II)) from contaminated soils. To this end, the investigators applied a completely randomized design with the factorial arrangement and four replications. The results indicated that all the evaluated parameters of S. Marianum, including shoot and root fresh and dry weight, as well as shoot and root Cd, were significantly influenced by Cd (II) concentration and diesel oil (DO). The Cd-contaminated soil showed minor declining effects on the produced plant biomass, whereas the DO-contaminated soil had more inhibitory effects. Moreover, the soil contaminated with both Cd and DO led to adverse effects on the plant biomass. The shoot and root Cd concentration had an increasing trend in the presence of DO as the bioconcentration factor (BCF) by 1.740 (+90.78%), 1.410 (+36.89%), 2.050 (+31.41%), 1.68 (+32.28%), and 1.371 (+22.41%) compared to the soil without DO at Cd (II) concentrations of 20, 40, 60, 80, and 100 mg/kg, respectively. Biological accumulation coefficient also showed the same trend as the BCF. In all the treatments, the translocation factor was >1. Therefore, it was demonstrated that milk thistle had high potential for transferring Cd from root to shoot and reducing its concentration in the soil. Moreover, the study revealed that milk thistle had high potential for absorbing Cd in the soil contaminated with Cd and DO.