AB0223 COXITIS AND ATLANTOAXIAL SUBLUXATION IN RHEUMATOID ARTHRITIS: IS THERE A LINK?

Background

Rheumatoid arthritis (RA) is an autoimmune chronic inflammatory disease that can over time be debilitating and life threatening vital prognosis through Atlantoaxial subluxation(ASS) and functional prognosis through coxitis.

Objectives

The aim of this work was to determine the correlation between coxitis and AAS in RA.

Methods

We performed a cross-sectional comparative study including 182 patients with RA meeting the ACR-EULAR 2010 criteria in a rheumatology department during the period from 2000 to 2021. The socio-demographic, clinical and radiological features were collected.

Results

Among the 182 patient enrolled, 16.4% (n=30) of patients had coxitis: unilateral in (90.24%; n = 27) and bilateral in (9.76%; n = 3). The coxitis was significantly found in males with a percentage of 40% vs 13.5% in females (p=0.01).

As it for the AAS, it was noted in 13.3% of our patients more frequently in males 41.2% vs 17.8% in females (p=0.044).

The discovery of AAS on standard radiographs was fortuitous in 70.4% of cases (systematic radiographic assessment for structural assessment of RA) and in 29.6% of cases presenting an inflammatory neck pain.

Cervical MRI was pathological in 63.4%. The abnormalities observed on MRI were: C1 – C2 synovitis (47.6%), confirmed LAA (42.9%) and basilar impression (9.5%).

C1-C2 instability was presumed anterior (90.9%), lateral (6.1%) and rotatory (3%). Two patients had basilar impression.

The occurrence of an atlantoaxial subluxation was significantly correlated to the anterior presence of a coxitis (p=0.000).

Conclusion

Our study suggest that in RA, the presence of a coxitis;mostly in males; can be a predictive factor for the occurrence of AAS but further studies are needed to confirm these results.

Disclosure of Interests

None declared

New neural network classification method for individuals ancestry prediction from SNPs data

Artificial Neural Network (ANN) algorithms have been widely used to analyse genomic data. Single Nucleotide Polymorphisms(SNPs) represent the genetic variations, the most common in the human genome, it has been shown that they are involved in many genetic diseases, and can be used to predict their development. Developing ANN to handle this type of data can be considered as a great success in the medical world. However, the high dimensionality of genomic data and the availability of a limited number of samples can make the learning task very complicated. In this work, we propose a New Neural Network classification method based on input perturbation. The idea is first to use SVD to reduce the dimensionality of the input data and to train a classification network, which prediction errors are then reduced by perturbing the SVD projection matrix. The proposed method has been evaluated on data from individuals with different ancestral origins, the experimental results have shown the effectiveness of the proposed method. Achieving up to 96.23% of classification accuracy, this approach surpasses previous Deep learning approaches evaluated on the same dataset.

Assessment of the performance of some new insecticides for the control of the vine mealybug Planococcus ficus in a Tunisian vineyard

Mealybugs (Hemiptera: Pseudococcidae) cause major economic losses in many Tunisian grapegrowing areas. In an attempt to improve management strategies for the Vine Mealybug (VM) Planococcus ficus (Signoret), three insecticides, imidacloprid, Prev-Am® and spirotetramat, were evaluated for their effect on this insect on vine, with reference to methidathion. The systemic insecticide spirotetramat (Movento® 150 OD) provided the greatest control performance of the VM populations, compared to the contact insecticide methidathion, the systemic insecticide imidacloprid applied through furrow irrigated system, and to Prev-Am®, a new contact biopesticide. Three weeks after treatment, VM eggs and adult females were missing from spirotetramat-treated vines. Additionally, spirotetramat supplied a long-residual activity against VM populations and prevented further spread of these insects on vine leaves. Therefore, this new systemic insecticide could be incorporated in an Integrated Pest Management program for VM control in Tunisian vineyards. Despite its short-residual activity, Prev-Am® was shown to be more effective than both methidathion and imidacloprid, mainly on VM eggs and L3 nymphs, and resulted in the highest level of VM L1-L2 nymph decrease on vine trunks. Hence, this biopesticide might prove useful for VM management in vineyards. 

Incorporation of β-Glucans into Pasta Extracted from Two Tunisian Barley Cultivars

The main objective of this study is to extract water-soluble barley (1→3) and (1→4)-β-d-glucans (β-glucans) from milled seeds of two common Tunisian barley cultivars (Manel and Rihane). A mixture of these barley β-glucans was added to spaghetti made with semolina of durum wheat. Cooking quality related traits of functional spaghetti made with durum wheat semolina was investigated. Four spaghetti samples prepared from semolina added with β-glucan ratios: 1, 3, 5 and 7 g/100 g; were developed and compared to the check. Samples were assessed for water absorption, optimal cooking time, cooking loss, swelling index, colour, carotenoids pigments, hardness, moisture, proteins and ash content. Results indicated that spaghetti added with Tunisian barley β-glucans have a good brightness and acceptable general aspect compared to the check. Spaghetti samples showed lower moisture and proteins contents and higher mineral contents and cooking loss. Lower swelling index and hardness properties were noted in incorporated pasta.

Steviol glycosides targeted analysis in leaves of Stevia rebaudiana (Bertoni) from plants cultivated under chilling stress conditions

Stevia rebaudiana is an important agricultural crop for the production of a high-potency natural sweetener, sensitive to low temperature during the developmental stage. Stimulation of chilling stress with a pre-treatment with endogenous signalling components and in particular with salicylic acid (SA), hydrogen peroxide (H2O2), 6-benzylaminopurine (BAP) and calcium chloride (CaCl2) could induce tolerance to chilling and could constitute a suitable way to maintain quality and quantity of steviol glycosides under controlled artificial environment. In the present work the effects of different putative signalling molecules on the morpho-physiological parameters were evaluated, and a specific method for the quali-quantitative analysis of steviol glycosides in S. rebaudiana plants cultivated under controlled conditions was developed, by using LC-ESI-FT (Orbitrap) MS, LC-ESI-QqQ-MS/MS and multivariate data analysis. This approach underlined that the pre-treatment has influence on the production of secondary metabolites. In particular Stevia plants characterised by higher contents of rebaudioside A and stevioside, were identified.

First Report of Mature Citrus Trees Being Affected by Fusarium Wilt in Tunisia

Citrus is an important crop in Tunisia and over 98% of trees of all varieties are grafted on sour orange rootstock. Since September 2010, unusual wilt symptoms have been observed in Takilsa, Bni-Khaled, and Manzel Bouzalfa fields that eventually caused tree death. The disease was observed on 10- to 25-year-old trees of sweet orange (Citrus sinensis) 'Washington Navel' and on 'Clementine' tangerines (C. tangerina) 'Cassar,' 'Hernandina,' and 'MA3,' all grafted on sour orange (C. aurantum) 'Bigarade Gou Tou.' The most conspicuous symptoms were wilting of sections of the canopy, chlorosis and epinasty of young leaves, and discoloration of vascular tissue. No root rot was observed. The problem was widespread with a disease incidence of 45 to 67%. Similar symptoms were described by Timmer et al. (2) on Mexican lime (C. aurantiifolia) nursery plants and some other species of citrus. Three representative isolates of Fusarium oxysporum Schlechtend.:Fr. from crown were single-spored and identified by the production of characteristic, three- to five-celled, sickle-shaped macroconidia with foot-shaped basal cells, ellipsoid microconidia borne in false heads on short monophialides, and chlamydospores in culture (1). The internal transcribed spacer (ITS) region of rDNA and the elongation factor (TEF 1-α) were amplified with primers ITS1/ITS4 and (TEF1/TEF2), respectively. GenBank accessions of ITS region are KC282838, KC282839, and KC282840, for TEF 1-α region are KF531633, KF537336, and KF537337, showed 99% homology with isolates of F. oxysporum in Fusarium-ID data. Pathogenicity tests were conducted on 7-month-old seedlings of sour orange using 10 plants for each of the three isolates. Prior to inoculation, roots were scraping with a sterile scalpel and plants were dipped in a conidial suspension of F. oxysporum (10⁶ conidia ml^-1) for 10 min. Each seedling was planted in a separate pot containing 0.7 liter of sterile soil. Non-inoculated plants with scraped roots dipped in sterile distilled water served as controls. Plants were irrigated and placed in a greenhouse at 24 ± 2°C and 12-h photoperiod. One month after inoculation, leaf chlorosis was observed and 2 months later, 90% of inoculated plants presented a severe wilt. Symptoms on infected plants were similar to those observed in the field. F. oxysporum was successfully re-isolated from the stems, thereby completing Koch's postulates. Genomic DNA was isolated from the re-isolations and PCR amplification of the ITS region was performed with the same primers. There was 100% nucleotide identity with sequences of the original isolates. To our knowledge, this is the first report of fusarium wilt of citrus trees in Tunisia. The pathogen may represent a new form species because previously, the disease was only reported from lime and lemon. References: (1) J. F. Leslie and B. A. Summerell. Page 256 in: The Fusarium Laboratory Manual. Blackwell Publishing Professional, Hoboken, NJ, 2006. (2) L. W. Timmer et al. Phytopathology 72:698, 1982.

Effects of arbuscular mycorrhizal inoculation and fertilization on mycorrhizal Statute of Jacaranda mimosifolia D.Don cultivated in nurseries

The effects of fertilization and the nature of the inoculum as well as the variation of the dose intake of the latter on the level of Jacaranda mimosifolia D.Don mycorhization were tested. Young plants were treated with two inoculums presenting different origins, compositions and modes of application: one is a commercial product containing Glomus irregulare, and the other is a composite indigenous inoculum resulting from trapping five species of genus Glomus and also from multiplication on mycotrophic plants: leek (Allium porrum L.) and vetch (Vicia sativa L.). For each inoculum, two doses were tested and for each dose of inoculum, four levels of fertilization based on a complete commercial fertilizer (Osmocote) were tested: 0 g/plant, 2 g/plant, 4 g/plant, and 6g/plant. Three repetitions were performed for each combination treatment of inoculum/fertilizer. One-year-old young Jacaranda plants, being about 40 cm high, were cultured under greenhouse in 10/12 cm caliber pots. After six months, all the inoculated plants were mycorrhized. According to endomycorrhizal structures found on their roots, plants receiving doses of composite indigenous inoculum reached a more advanced stage of mycorrhization than those treated with the commercial inoculum. The existence of an interaction effect between the inoculum dose and the level of fertilization on Jacaranda mycorhization rate was excluded. These two parameters of variation were studied as simple effects. The increase in commercial inoculum dose had a significant positive influence on the level of Jacaranda plants mycorrhization (P=0.05). The rate of mycorrhization jumped from 12.69% to 21.92%. Nonetheless, for plants receiving increasing doses of composite indigenous inoculum, the level of mycorrhization has varied randomly. In both instances of inoculum treatments, increasing the dose of fertilizer significantly inhibited endomycorrhizal colonization of Jacaranda roots (P=0.01). Thus, the rate of root colonization decreased from 47.43% to 2.41% for plants receiving the composite indigenous inoculums. It decreased from 32.35% to 3.95% for those treated with the commercial inoculum. Mycorrhization had a positive effect on root dry biomass of Jacaranda, as in the case of unfertilize ave the highest rates of colonization.

Protective effect of Bacillus amyloliquefaciens against infections of Citrus aurantium seedlings by Phoma tracheiphila

Isolate TEB1 an antagonistic endophytic bacterium, obtained from citrus leaves and identified as Bacillus amyloliquefaciens by 16S rDNA sequencing, was used for the biological control of mal secco disease of Citrus aurantium seedlings caused by the mitosporic fungus Phoma tracheiphila. The isolate TEB1 exhibited a good in vitro activity against P. tracheiphila in dual cultures as well as with the well diffusion method. C. aurantium seedlings watered with a suspension of TEB1 cells showed a reduction of 53.61 and 48.63% in disease severity and incidence, respectively. A PCR test with specific primers was performed 365 days after inoculation and P. tracheiphila was detected along the whole stem in inoculated control plant while no amplification product was obtained in TEB1 treated seedlings. Molecular analysis of TEB1 revealed a positive amplification of fenD and ituC genes responsible of the biosynthesis of fengycin and iturin lipopeptides, respectively. Moreover, observations by optical microscope showed that TEB1 reduced by 55% the germination of P. tracheiphila conidia and exhibited a marked effect on mycelia structure. Data suggest that lipopeptides produced by the bacterium interact with the cytoplasmic membrane of the fungus causing pore formation. TEB1 appears a potential candidate for the biological control of citrus mal secco disease.

Role of arbuscular mycorrhizal symbiosis in root mineral uptake under CaCO3 stress

This study investigated the effects of increasing CaCO(3) concentrations (0, 5, 10, 20 mM) on arbuscular mycorrhizal (AM) symbiosis establishment as well as on chicory root growth and mineral nutrient uptake in a monoxenic system. Although CaCO(3) treatments significantly decreased root growth and altered the symbiosis-related development steps of the AM fungus Rhizophagus irregularis (germination, germination hypha elongation, root colonization rate, extraradical hyphal development, sporulation), the fungus was able to completely fulfill its life cycle. Even when root growth decreased more drastically in mycorrhizal roots than in non-mycorrhizal ones in the presence of high CaCO(3) levels, the AM symbiosis was found to be beneficial for root mineral uptake. Significant increases in P, N, Fe, Zn and Cu concentrations were recorded in the mycorrhizal roots. Whereas acid and alkaline phosphatase enzymatic activities remained constant in mycorrhizal roots, they were affected in non-mycorrhizal roots grown in the presence of CaCO(3) when compared with the control.

Calcareous impact on arbuscular mycorrhizal fungus development and on lipid peroxidation in monoxenic roots

The present work underlined the negative effects of increasing CaCO(3) concentrations (5, 10 and 20 mM) both on the chicory root growth and the arbuscular mycorrhizal fungus (AMF) Glomus irregulare development in monoxenic system. CaCO(3) was found to reduce drastically the main stages of G. irregulare life cycle (spore germination, germinative hyphae elongation, root colonization, extraradical hyphae development and sporulation) but not to inhibit it completely. The root colonization drop was confirmed by the decrease in the arbuscular mycorrhizal fungal marker C16:1ω5 amounts in the mycorrhizal chicory roots grown in the presence of CaCO(3). Oxidative damage evaluated by lipid peroxidation increase measured by (i) malondialdehyde (MDA) production and (ii) the antioxidant enzyme peroxidase (POD) activities, was highlighted in chicory roots grown in the presence of CaCO(3). However, MDA formation was significantly higher in non-mycorrhizal roots as compared to mycorrhizal ones. This study pointed out the ability of arbuscular mycorrhizal symbiosis to enhance plant tolerance to high levels of CaCO(3) by preventing lipid peroxidation and so less cell membrane damage.

Pathotype and microsatellite analyses reveal new sources of resistance to barley scald in Tunisia

We examined the variation and relationships between pathogenicity and a microsatellite-based haplotype in 79 Tunisian Rhynchosporium secalis isolates that were collected from the most commonly cultivated barley populations in Tunisia, Rihane cv. and local landraces, with the goal of finding genes that might be used to monitor resistance to scald. Isolates could be classified into three distinct virulence groups based on artificial inoculation of 19 differential cultivars with known scald resistance genes. The resistance gene BRR2 carried by the Astrix differential cultivar appeared to be the most effective in Tunisia. Pathotypes sampled from the Rihane host were more virulent than those sampled from local barley landraces. Because some differential cultivars that carried the same resistance genes showed different reaction patterns to 48 of the isolates, we postulated that other unknown resistance gene(s) specific to Tunisian isolates may be prevalent and could be used in Tunisian barley breeding programs. Microsatellite fingerprinting allowed the detection of 11 alleles linked to the virulence and pathogenic identification of 52% of the tested isolates. Thus, microsatellite analysis may provide a rapid tool for pathogen detection, without an inoculation step that requires long incubation periods before ultimate disease assessment.

Genetic diversity of Rhynchosporium secalis in Tunisia as revealed by pathotype, AFLP, and microsatellite analyses

Genetic variability among 122 Rhynchosporium secalis isolates collected from barley in three regions of Tunisia was investigated using host differentials, amplified fragment length polymorphism (AFLP), and microsatellite markers. The isolates were collected from a widely grown scald-susceptible barley cultivar Rihane and a range of local landrace cultivars in geographically distinct regions with different agroclimatic conditions. Pathotypic diversity (the proportion of unique pathotypes) was high in R. secalis populations from the high (100% diversity), moderate (95%), and low (100%) rainfall areas of Tunisia, and from both Rihane (which is the sole variety grown in the high rainfall region) and local landraces (which predominate in the low rainfall area). This may reflect a general adaptability for aggressiveness and suggests that the widely grown cultivar Rihane has exerted little or no selection pressure on the pathogen population since its release in 1983. Genotypic diversity (GD), defined as the probability that two individuals taken at random had different genotypes, was high for populations from Rihane, local landraces, and different agro-ecological zones (GD = 0.96-0.99). There was low genetic differentiation among pathogen populations from different host populations (G(ST) < or = 0.08, theta < or = 0.12) and agro-ecological zones (G(ST) < or = 0.05, theta < or = 0.04), which may be partly explained by gene flow due to the movement of infected stubble around the country. There was no correlation (r = 0.06, P = 0.39) between virulence phenotype and AFLP haplotype. A phenetic tree revealed groups with low bootstrap values that did not reflect the grouping of isolates based on host, pathotype, or agro-ecological region. The implications of these findings for R. secalis evolutionary potential and scald-resistance breeding in Tunisia are discussed.