Observer design for Takagi-Sugeno fuzzy systems with unmeasured premise variables: Conservatism reduction using line integral Lyapunov function.

In this paper, a non-quadratic Lyapunov function is employed to reduce conservatism in a nonlinear observer designed for a class of continuous-time Takagi-Sugeno fuzzy systems with unmeasurable premise variables. This structure presents greater challenges compared to systems with measured variables. To overcome this issue, we utilize the mean value theorem and the sector nonlinearity transformation to convert the nonlinear error dynamics into a linear parameter-varying system. Moreover, we introduce the line integral Lyapunov function, which based on the integral of the membership functions, in order to ensure the global stability of the fuzzy systems under consideration. The use of this function offers several notable advantages over conventional quadratic forms, including a reduction in conservatism. Additionally, this type of functions constructed in a manner that eliminates the need for generating time derivatives of the membership functions, thereby simplifying calculations and analysis in comparison to other nonquadratic functions. Furthermore, it also enables capturing the system's behavior along a trajectory. The stability conditions are more relaxed and expressed as linear matrix inequalities, which can be solved using a linear programming approach through specialized software tools. To validate the effectiveness of the proposed methodology, we conducted a hardware-in-the-loop test using a flexible joint robot. The obtained results clearly underscore the success of the proposed approach.

[Musculoskeletal hand disorders in musicians]. / Les pathologies musculo-squelettiques de la main chez les musiciens.

Music is often associated with joy, pleasure and leisure. However, like any other profession, it has its constraints and risks.The purpose of this update is to present a non-exhaustive inventory of musculoskeletal hand disorders most frequently associated with music practice.All music instruments are concerned. The difference lies in damage location as well as in the frequency of specific pathologies according to the used instrument. The most feared disorder by musicians is focal dystonia, which is characterized by a painless and repetitive coordination disorder. It only appears in the realization of specific professional movements. The overuse syndrome and the nerve entrapment syndrome constitute other dreaded disorders. Specific and multidisciplinary care is often necessary.

La musique rime souvent avec joie, plaisir et loisir. Cependant, comme toute autre profession, elle a ses contraintes et ses risques. Cette mise au point a pour objectif de faire un inventaire, non exhaustif, des pathologies musculo-squelettiques de la main les plus fréquemment associées à la pratique de la musique. Aucune famille d'instruments n'est épargnée. La différence réside dans la localisation de l'atteinte ainsi que dans la fréquence de l'association entre certains instruments et une pathologie précise. La dystonie de fonction, caractérisée par un trouble de la coordination indolore mais répétitif, est une pathologie redoutée par les musiciens. La symptomatologie ne se manifeste que lors de la réalisation de certains gestes professionnels précis. Le syndrome de surmenage ainsi que les syndromes canalaires peuvent également se rencontrer. Une prise en charge spécifique et multidisciplinaire est souvent nécessaire.

SAPHO Syndrome Mimicking Infectious Spondylodiscitis and Bone Metastasis.

The acronym SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) includes diseases with similar osteoarticular manifestations and skin conditions. Making this diagnosis is not always obvious, especially when the clinical presentation does not fit the typical pattern of the disease or it occurs in a particular field. We described three cases where the diagnosis was difficult. A 46 year-old woman presented with cervical pain. The cervical X-ray showed the aspect of an ivory C5 vertebra. The patient had, however, preserved general condition, no signs of underlying neoplasia, nor other joint complaints. Blood analysis was normal. Tomography did not find any suspect lesion but showed sclerosis and hyperostosis of the manubrium. Scintigraphy showed the characteristic "bullhead" appearance. A 61-year-old woman had thoracic and lumbar pain. MRI showed spondylodiscitis in D3-D4, D4-D5, D5-D6, D6-D7, and L1-L2 with paraspinal soft tissue involvement, simulating infectious spondylodiscitis. Infectious investigations and discovertebral biopsy performed twice were negative. SAPHO syndrome was then suspected. Bone scintigraphy showed uptake in the chondrosternal articulations and D4 to D7 vertebrae. The diagnosis of SAPHO was established. The third case was a 46-year-old man with a lung adenocarcinoma. Staging for metastatic disease, a TAP tomography was performed and showed osteosclerosis of D8 to D12 and intra-articular bridges in the sacroiliac joints. MRI and scintigraphy eliminated malignancy and confirmed the diagnosis of SAPHO. In our cases, imaging findings could facilitate differentiating SAPHO syndrome from other diseases.

[Clinical, radiographic and biologic particularities of ankylosing spondylitis in Tunisian patients according to the presence or the absence of the HLA B27 and its sub-types]. / Particularités cliniques, radiologiques et biologiques de la spondylarthrite ankylosante en Tunisie selon la présence ou l'absence du HLA B27 et de ses sous-types.

To assess the clinical, radiographic and biologic particularities of ankylosing spondylitis (AS) in Tunisian patients according to HLA B27 and its sub-types statute. This was a case-control study that included 100 patients (85 males/15 females) with AS according to the modified New York criteria. Demographic, clinical, AS specific indexes, radiographic and biologic parameters were determined. HLA-B and B27 subtypes typing of all subjects were performed by PCR-SSP. Patients mean age was 38.4 years +/- 12.6 HLA-B27 was found in 62% of patients. The comparison of B27 positive and B27 negative patients revealed a correlation of B27 with age, male gender, family history of spondylarthropathies, age at disease onset, acute onset of the disease, inaugural spinal involvement, uveitis, bilateral and destructive hip arthritis as well as a high score of mSASSS. The most frequent sub-types of HLA B27 were B*2702 (49.2%) and B*2705 (36.3%). No significant difference of the clinical presentation of the disease or severity factors was found among these patients. This study confirmed the contribution of the HLA B27 to the determination of the clinical presentation of AS. The variability of factors linked to B27 may be explained by the polygenic model of the disease.

Comparative study of indices of activity evaluation in rheumatoid arthritis.

INTRODUCTION: Choosing between the different indices of activity evaluation in RA is often difficult considering the very heterogeneous clinical expression of the disease. The objective of our study was to evaluate the level of similarity between SDAI, CDAI, DAS28-(ESR) and DAS28-(CRP) indices in the evaluation of RA activity. PATIENTS AND METHODS: In this transversal study, a total of 100 patients with RA responding to the ACR 87 criteria were followed up for a period of 20 months. The correlations between the four indices were studied through the Pearson's correlation coefficient (r). The similarity between these tools was evaluated through Kendall's (K) "tau" similarity coefficient. RESULTS: The 87 female and 13 male patients (sex ratio: 6.7F/1M) were of a mean age of 52.9±11.6 years (17-77) and have been living with RA for a mean of 8.3±9 years (2 months-41 years). The DAS28-(ESR) mean score was 5.53±1.46 [1.25-8.05]. The DAS28-(CRP) mean score was 5.01±1.44 [1.68-7.81]. The CDAI mean score was 30.72±15.04 [2-62] and that of SDAI was 28.86±15.86 [2.3-71.3]. A positive, statistically significant correlation was noted between the four indices of RA activity. The level of similarity between the different indices was good (K variation between 0.758 and 0.943). DAS28-(ESR) allowed classifying the patients in the same category of disease activity than DAS28-(CRP) in a proportion of 85%. This proportion was 88% when comparing DAS28-(ESR) to CDAI and SDAI, respectively. Regarding DAS28-(CRP) and CDAI, these two indices classified the patients in the same category in a proportion of 80%, compared to 87% regarding DAS28-(CRP) and SDAI. Finally, CDAI and SDAI classified the patients in the same category in a proportion of 92% with an excellent level of similarity. CONCLUSION: Different evaluation indices of RA activity are currently available. DAS28 is the most used. CDAI and especially SDAI have a good level of similarity with DAS28. Their advantage is to be simple and quick, and seem therefore well adapted to the follow-up of outpatients.

[Scapulohumeral hydatidosis: a new case in Tunisia]. / L'hydatidose scapulohumérale: à propos d'une nouvelle observation en Tunisie.

Osseous hydatidosis is reported in only 0.5-2.5% of the cases. The scapulohumeral localization is extremely rare. A 39-year-old woman, born in a rural area of Tunisia, presented swelling and tenderness of the left shoulder with limited motion 7 days after a minor trauma. Plain radiographs, CT and MRI showed osteolytic scapulohumeral lesions, cortical rupture and multiple cysts in the muscles, which were suggestive of hydatidosis. Indirect haemagglutination test using hydatid antigen was positive (1/280). The patient refused radical surgery and underwent resection of axillary cysts. Albendazole was given in the recommended dose but was stopped immediately due to hepatic toxicity. Scapulohumeral hydatidosis is extremely rare, often invasive and behaves like a locally malignant bone tumour. Its treatment is also difficult.

Clinical significance of Th1/Th2 ratio in patients with myelodysplastic syndrome.

In this study, we attempted to evaluate the clinical significance of T helper 1 (Th1)/T helper 2 (Th2) ratio in patients with myelodysplastic syndrome (MDS), five refractory anaemia (RA), four refractory anaemia with ringed sideroblasts (RARS), 31 refractory cytopenia with multilineage dysplasia (RCMD), nine refractory anaemia with excess blast-1 (RAEB-1) and seven refractory anaemia with excess blast-2 (RAEB-2). Intracellular interleukin-4 (Th2 cytokine) and interferon-gamma (Th1 cytokine) production was assessed in CD4+ T lymphocytes activated by phorbol 12-myristate 13-acetate and ionomycin using flow cytometry. Mean Th1/Th2 ratios in each MDS group were as follows: RA/RARS, 8.8 (95% CI, 5.8-11.8), RCMD, 14.7 (95% CI, 9.5-19.9), RAEB-1, 10.6 (95% CI, 4.6-16.6), RAEB-2, 12.8 (95% CI, 3.0-22.7) and control 12.8 (95% CI, 9.6-16.1). There were no significant differences in Th1/Th2 ratio in the RA/RARS, RCMD, RAEB-1 and RAEB-2 subgroups when compared to controls. Because Th1/Th2 ratio in the RCMD group was widely distributed, we divided RCMD patients according to Th1/Th2 ratio into three groups (low, normal and high Th1/Th2 groups). There were no differences in severity of cytopenia among the three above groups. However, the percentage of CD8 cells in the low Th1/Th2 group was significantly lower than those in the high group (P < 0.01). These data suggest that Th1/Th2 imbalance induces CD4/CD8 imbalance, and serves as a marker of the biological interplay in immune regulation.

[Cervicobrachial neuralgia revealing neurosarcoma]. / Névralgie cervicobrachiale révélatrice d'un neurofibrosarcome (MPNST) cervical.

Malignant peripheral nerve sheath tumor (MPNST) or neurofibrosarcoma, previously described as malignant Schwannoma or neurosarcoma, is an extremely rare cause of malignancy localized in the neck. Half of reported cases occurred in patients with neurofibromatosis in Von Recklinghausen disease type I. Typical features include high grade malignancy and a tendency to recurrence and distant metastases. We report the case of a 56-year-old woman with neurosarcoma of the neck, which was revealed by a cervicobrachial neuralgia. The physical examination found a mass on the left side of the neck. Plain radiographs showed osteoarthritis. MRI showed a well-defined paravertebral mass. Pathologic diagnosis was neurosarcoma. Radiotherapy was delivered.

[Using prenatal care in the Tunisian context: barriers and motivation factors]. / Recours aux visites prénatales dans le contexte tunisien: barrières et facteurs de motivation.

Several barriers to and motivators of antenatal care are analysed in the context of a developing country. The authors found that socio-cultural factors are as important as organizational factors in motivating women to seek antenatal care. While social and economic development may improve the quality of life in the long term, it is important to respond now to the needs of pregnant women in order to encourage them to use such services. A comprehensive analysis of certain organizational factors would be useful in achieving this goal.