Organic acid bioavailability from banana and sweet potato using an in vitro digestion and Caco-2 cell model

Introduction  

Organic acids from plant food have been shown to play an important role in the prevention of chronic diseases (osteoporosis, obesity), inherent to western diets, but little is known about their bioavailability in the small intestine, information that needs to be determined in order to quantify likely effects on human health.     

The in vitro evaluation of anti-chlamydial and cytotoxic properties of dermaseptin S4 and derivatives: peptides from amphibian skin

Chlamydia trachomatis is an obligate intracellular bacterium responsible for a number of health problems, including sexually transmitted infection in humans. Efforts were made for the search of alternative therapies. Accordingly, the present study was undertaken to perform a systemic in vitro investigation on the anti-chlamydial potential of cationic peptides from frog’s skin, namely dermaseptin S₄ (S₄) and its derivatives. Several strains of Chlamydia trachomatis serovar E were used to detect the antimicrobial activity of the new compounds. The infections tests and the toxic effects of the new compounds were determined using McCoy cells monolayers. Our data show that S₄ exhibited a potent anti-chlamydial activity and found that these peptides blocked infection of McCoy cells and reduced the numbers of inclusion-forming units (81 %) after 48 h at low concentration (5 μg/ml). Besides, the finding revealed that increasing the number of positive charges of the peptide resulted in a reduced cytotoxicity without affecting the antimicrobial effect. Among all peptides, the derivative K₄K₂₀S₄ was the more potent to inhibit C. trachomatis growth with 96 % reduction in the number of chlamydial inclusions compared with an untreated control infection and, therefore, can be considered as potential agents for therapy of Chlamydia infectious diseases.     

Conflicting Views on the Molecular Structure of the Cancer Antigen CA125/MUC16

CA125 is a tumor antigen used to monitor the progression and regression of epithelial ovarian cancer. Despite the widespread use of CA125, the biochemical and molecular nature of this antigen is poorly understood. Analysis of the structure of CA125 is essential for determining the physiological role of this very significant tumor marker. Accumulated experimental evidence has shown that CA125 epitopes reside on a molecule of very complex architecture in terms of both protein backbone and oligosaccharide structures. It is not clear whether the heterogeneity of CA125 molecular characteristics are due to the variability of biological sources from which the molecule was isolated or to the different biophysical methods used for the characterization of all the oligosaccharides linked to CA125 or to the presence of glycoisoforms for this protein. This review attempts to summarize emerging data related to molecular characteristics of CA125 and to compare approaches undertaken to reach a better understanding of molecular features of this tumor marker.     

Primary hyperoxaluria in children in central Tunisia

AIM: The goal of this work is to analyze clinical and therapeutics particularities of primary hyperoxaluria in children in Tunisian centre. METHODS: We studied retrospectively 15 cases of primary hyperoxaluria enrolled during 9 years period (1994-2002). RESULTS: It is about 2 boys and 13 girls (sex - ratio = 4.5) aged 2 month to 13 years (mean age: 4 years). Six patients presented the infantile form and nine the juvenile form of HP. At the moment of diagnosis, renal function was normal in one patient, moderately altered in another and severely altered in the other patients. All patients had nephrocalcinosis and 6 among them radio-opaque renal calculi associated. Diagnosis of HP was established in 11 cases by hyperoxaluria and/or important hyperoxalemia or on the data of the renal biopsy and biochemical analysis of renal calculi in 4 cases. The so-called "maghrebin" mutation (Ile244Thr) sought-after in 9 children, has cannot be identified that in 2 among them. Eight patients died of the continuations of their illness. The seven other patients again in life present a terminal renal insufficiency treated by haemodialysis. No patient could benefit from organ transplantation. CONCLUSION: Primary hyperoxaluria is a very heterogeneous disease on the plan clinic that genetic. In Tunisia where it constitutes a frequent cause of end stage renal failure, prenatal diagnosis of this disease is of a big interest.     

Primary Gingival Melanoma: An Important Entity

Primary melanoma of the mandibular gingiva is extremely rare. It is often misinterpreted as a benign pigmented process. The prognosis of this entity is very poor. We report here the first case of primary gingival melanoma described in the Tunisian literature about a 55-year-old smoker having cerebral and pulmonary metastases from gingival melanoma at diagnosis. Our patient underwent brain radiotherapy at a dose of 18 Gy in three sessions but he died with a decline of 3 months before starting systemic therapy. Therefore, each new case should be illustrated to make clinicians aware about the importance of the early diagnosis to improve the poor diagnosis of this entity.     

Natural evolution of hepatitis C virus infection in hemodialysis Tunisian patients and CTLA-4 SNP's

AIM: To analyze the polymorphisms of CTLA-4 gene involved in the response against hepatitis C virus(HCV) infection.METHODS: We recruited 500 hemodialysed patients from several hemodialysis centers, all HCV-antibody positive, spread over different regions of Tunisia, as part of a national survey in 2008 conducted in the laboratory of immunology at the Charles Nicolle hospital Tunisia, classified into two groups G1(PCR+) and G2(PCR-) according to the presence or absence of viral RNA. Of these patients, 307 were followed prospectively on a viral molecular level over a period from 2002 to 2008, divided into two groups based on the persistence and viral clearance. PCR-RFLP was performed for the analysis of SNPs(+49) A/G and(+6230) G/A CTLA-4 for these 500 patients and 358 healthy controls.RESULTS: Analysis of clinical and virological charac-teristics of our cohort suggests a nosocomial infection in our hemodialysed patients with transfusion history as a primary risk factor and a predominance of genotype 1b. The haplotype analysis revealed an increase of frequencies of GG(+49)/(CT60) CTLA-4 in the entire patients group compared to controls(P = 0.0036 and OR = 1.42; 95%CI: 1.12-1.79, respectively). This haplotype is therefore associated with susceptibility to HCV infection. CONCLUSION: Our study suggests a possible role of CTLA-4 polymorphisms in the outcome of HCV infection in the Tunisian hemodialysed population.     

Rare association between rheumatoid arthritis and Vogt-Koyanagi-Harada syndrome: A case-based review

IntroductionVogt-Koyanagi-Harada (VKH) syndrome is a systemic autoimmune disorder that targets tissues containing melanocytes such as the eye, inner ear, meninges and skin. Despite a common genetic susceptibility, the association between VKH syndrome and rheumatoid arthritis (RA) has been rarely reported.Aim of the workTo report a rare case with RA who developed incomplete VKH syndrome. The case is described and a review of the literature on similar cases is presented.Case reportA 26 year-old Tunisian woman, with a medical history of Hashimoto’s thyroiditis, was diagnosed on 2011 with seropositive and erosive RA treated with Leflunomide. She presented to the emergency department on June 2018 with bilateral blurred vision associated with photophobia, vomiting and severe headache that had gradually progressed over the preceding five days. Ophthalmological examinations showed typical findings of VKH syndrome. The patient received intravenous infusions of methylprednisolone at a daily dose of 1000 mg for 3 days that was followed orally with 2 mg/kg of prednisone equivalent. Given the lack of improvement in visual acuity after 3 weeks of treatment, azathioprine was added and VKH remission was achieved on September 2018 as confirmed on optical coherence tomography. However, the patient passed away on October 2018 due to infectious complications of the immunosuppressant agents.ConclusionTreatments and outcomes of VKH are variable. Pharmacological management of such an association between RA and VKH may be challenging, so care must be taken to balance treatment escalation with adverse events in patients at risk.     

IgA Fc receptor I signals apoptosis through the FcRgamma ITAM and affects tumor growth

The IgA Fc receptor (FcalphaRI) has dual proinflammatory and anti-inflammatory functions that are transmitted through the immunoreceptor tyrosine-based activation motifs (ITAMs) of the associated FcRgamma subunit. Whereas the involvement of FcalphaRI in inflammation is well documented, little is known of its anti-inflammatory mechanisms. Here we show that monomeric targeting of FcalphaRI by anti-FcalphaRI Fab or serum IgA triggers apoptosis in human monocytes, monocytic cell lines, and FcalphaRI+ transfectants. However, the physiologic ligand IgA induced apoptosis only when cells were cultured in low serum conditions, indicating differences with induction of anti-inflammatory signaling. Apoptosis signaling required the FcRgamma ITAM, as cells transfected with FcalphaRI or with a chimeric FcalphaRI-FcRgamma responded to death-activating signals, whereas cells expressing a mutated FcalphaRI(R209L) unable to associate with FcRgamma, or an ITAM-mutated chimeric FcalphaRI-FcRgamma, did not respond. FcalphaRI-mediated apoptosis signals were blocked by treatment with the pan-caspase inhibitor zVAD-fmk, involved proteolysis of procaspase-3, and correlated negatively with SHP-1 concentration. Anti-FcalphaRI Fab treatment of nude mice injected subcutaneously with FcalphaRI+ mast-cell transfectants prevented tumor development and halted the growth of established tumors. These findings demonstrate that, on monomeric targeting, FcalphaRI functions as an FcRgamma ITAM-dependent apoptotic module that may be fundamental for controlling inflammation and tumor growth.