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Maryem Ferjani,1 Yosra Zaimi,2 Nouha Trad,2 Yousra Hammi,1 Myriam Ayari,2 Shema Ayadi,2 Taha Sayari,1 Tahar Gargah1 1Department of Pediatrics, Charles Nicolle Hospital, Tunis, Tunisia; 2Department of Gastroenterology, Charles Nicolle Hospital, Tunis, TunisiaCorrespondence: Nouha Trad, Department of Gastroenterology, Charles Nicolle Hospital, Boulevard of April 9, 1938, Bab Saadoun, Tunis, 1007, Tunisia, Tel +216 50858104, Email nouha1med7@gmail.comBackground: Nephrotic syndrome (NS) is associated with a hypercoagulable state and may be complicated by thrombotic events. Venous thrombosis is well-acknowledged, while arterial thrombosis is rather unusual.Case Presentation: We present the case of a 20-year-old woman with a 12-year history of idiopathic NS revealed by extensive cerebral venous thrombosis with pulmonary embolism treated with anticoagulation therapy and oral corticosteroid therapy followed by mycophenolate mofetil (MMF). The thrombophilia assessment did not show any abnormalities. The evolution was marked by the occurrence of several NS relapses controlled by oral corticosteroid therapy until 2017. Subsequently, the patient had not presented a relapse of her disease. The anticoagulant treatment and the MMF were therefore stopped. One year later, the patient presented with severe diffuse acute abdominal pain associated with postprandial vomiting and bilateral lower limb edema. Laboratory results confirmed a NS relapse. An abdominal CT scan revealed acute thrombosis of the superior mesenteric artery with acute mesenteric ischemia. Intraoperative exploration showed mesenteric ischemia with extensive necrosis of the small intestine making their resections incompatible with life. The patient died after 48 hours.Conclusion: Mesenteric arterial thrombosis, which is a rare but life-threatening NS complication, should always be considered, especially in the case of acute non-specific digestive symptoms.Keywords: nephrotic syndrome, mesenteric ischemia, recurrence

Yosra Zaimi,1 Myriam Ayari,1 Asma Mensi,1 Linda Bel Hadj Kacem,2 Leila Achouri,3 Meriem Bouzrara,4 Yosra Said,1 Leila Mouelhi,1 Radhouane Debbeche1 1Department of Gastroenterology, Charles Nicolle Hospital, Tunis, Tunisia; 2Department of Pathology, Charles Nicolle Hospital, Tunis, Tunisia; 3Department of Oncologic Surgery, University of Tunis El Manar, Tunis, Tunisia; 4Department of Radiology, Charles Nicolle Hospital, Tunis, TunisiaCorrespondence: Myriam AyariDepartment of Gastroenterology, Charles Nicolle Hospital, Boulevard 9 Avril 1938 Bab Saâdoun, Tunis, 1006, TunisiaEmail ayari.myriam@hotmail.frAbstract: H syndrome is an extremely rare autosomal recessive affection caused by biallelic mutations in the SLC29A3 gene encoding the human equilibrative nucleoside transporter hENT3. The hallmark signs are cutaneous consisting of hyperpigmentation and hypertrichosis patches. Besides, associated systemic manifestations are highly various reflecting phenotypic pleiotropism. Herein, we report a first case of pseudo-Meigs’ syndrome occurring in a young Tunisian H syndrome diagnosed patient with a novel homozygous frameshift mutation in exon 2 of the SLC29A3 gene: p.S15Pfs*86 inducing a premature stop codon. The patient developed ascites associated with left ovarian mass and she underwent surgery. After tumor resection, ascites disappeared rapidly. Histological examination showed serous cystadenoma of the ovary orienting the diagnosis towards pseudo-Meigs’ syndrome.Keywords: H syndrome, SLC29A3 gene, rare disease, pseudo-Meigs’ syndrome, Tunisian patient

The modular multilevel converter (MMC) is an operational switch-mode converter topology which represents a potential solution for high-voltage direct current (HVDC) transmission applications. This paper deals with the dynamic performance of an MMC-based, back-to-back HVDC system. Through an Anti-Windup (AW) control method, an energy control strategy for the MMC is proposed. This approach allows to generate the desired optimal reference signals for the differential current loops with respect to its dynamic constraints. A combination between conventional PI/IP and anti-windup controllers is used to extract the advantages of each one. For MMC linked to HVDC systems, the same advanced controller combined to conventional controller of DC voltage will be applied to generate the desired active power reference and to regulate the DC bus voltage. The effectiveness of the proposed anti-windup control strategy for MMC-HVDC system is then evaluated through SPS Matlab/Simulink. Obtained results, of the two-terminal MMC-HVDC system-based anti-windup approach under different dynamic conditions, presents satisfactory dynamic responses. [ABSTRACT FROM AUTHOR]

Control of Voltage Source Converters (VSC)-based HVDC (High Voltage Direct Current) transmission systems is developed in this paper. The proposed approach aims at stabilizing the power VSC, which is characterized by nonlinearities due to requirements of power flow and DC bus voltage. The steady-state average model for the VSC-HVDC system is developed on linear and bilinear deviation state–space models around the working point. Based on poles placement and Least Squares (LS) methods, linear and nonlinear polynomial feedbacks are considered. The proposed approach leads to regulate simultaneously the dq grid currents and the DC bus voltage. By upon the time domain simulations in MATLAB/SIMULINK/SPS environment, the effectiveness of the proposed control strategies is tested on a VSC and a point-to-point VSC-HVDC transmission system. The simulation results show the robustness of the studied systems under various conditions. [ABSTRACT FROM AUTHOR]