An Mx1 promoter-reporter system to study interferon pathways in rainbow trout

A rainbow trout interferon (IFN) reporter system has been established by selection of a stable cell line, RTG-P1, transfected with a plasmid expressing the firefly luciferase gene under the control of the promoter for the IFN-induced gene Mx1. After 148 passages, the luciferase expression was still highly induced by polyinosinic:polycytidylic acid (poly I:C) in RTG-P1 cells. Different IFN inducers (dsRNA, viral hemorrhagic septicaemia virus or conditioned medium containing rainbow trout antiviral activity) were able to stimulate the IFN-reporter system in RTG-P1, showing that this cell line can be used to study the activation of the IFN pathway in various contexts. Pyrrolidine dithiocarbamate (PDTC), an NF-kappaB inhibitor, significantly blocked poly I:C induced luciferase accumulation in RTG-P1 at intermediate doses (1-10 microM), suggesting that Mx1 induction through the IFN signalling pathway is NF-kappaB-dependent in fish. This inhibition was not observed for doses of 50 microM or higher. The RTG-P1 reporter system constitutes an interesting tool to study the induction and regulation of IFN signalling in teleost fish.     

Protective effects of selenium (Se) and zinc (Zn) on cadmium (Cd) toxicity in the liver and kidney of the rat: histology and Cd accumulation

To assess the co-effect of Se and Zn on Cd accumulation in the liver and kidney and on their histology, male rats were exposed either to Cd, Cd+Zn, Cd+Se, or Cd+Zn+Se in their drinking water, during 35 days. Exposure to Cd resulted in its accumulation in the liver and kidney. In the Cd-Zn and Cd-Zn-Se groups, Cd contents in the two organs were significantly (p < 0.01) higher than those in the Cd group. Se did not induce any significant difference in hepatic and renal concentrations of Cd in comparison to Cd-treated group. Light microscopic examination indicated severe histological changes in the two organs under Cd influence. Se or Zn partially alleviated the damage observed in the liver. The same effect was remarked in the kidney with Se, but no differences in the renal histological structure have been observed between the Zn-Cd and the control groups. With Se and Zn simultaneous treatment during Cd exposure, the observed morphological changes had practically disappeared from the liver, but were only reduced in the kidney. CONCLUSION: Se and Zn can have a cooperative effect in the protection against Cd-induced structural damage in the liver but not in the kidney.     

Hydatid cyst of the parotid gland: six cases

Primary hydatid cyst of the parotid gland is still an exceptional localization. The parotid gland is an uncommon site, even in our country, in which echinococcal disease is endemic. We report six cases of primary hydatid cyst of the parotid gland who presented with an isolated mass. The diagnosis was based on ultrasonography, which showed a parotid gland cystic mass. The echinococcal immunologic test (enzyme-linked immunosorbent assay) was positive in two cases. The surgical treatment consisted of total resection of the cyst, without rupture of the cystic wall and preserving the gland, in four cases and resection of the prominent dome in two cases. The diagnosis was confirmed on macroscopic examination of the resected pieces. In all cases, the postoperative course was uneventful. There was no recurrence at the 17-month follow-up.     

Childhood cutaneous tuberculosis: a 20-year retrospective study in Tunis

Despite prevention programs, tuberculosis is still endemic in developing countries. We assessed the epidemiologic and clinical profiles of childhood cutaneous tuberculosis in our dermatology department from 1981 to 2000 and compared it to previous Tunisian reports and to the relevant literature. This is a retrospective study over a 20-year period (1981-2000) in a large teaching hospital of the capital. Patients included were below age 15 years. Diagnosis was based upon clinical examination, tuberculin reaction, histopathology and response to antitubercular therapy. There were 26 patients with cutaneous tuberculosis, 0.1 percent of the total number of dermatology outpatients for that time period. Of these 26, seven (27 %) were immunocompetent. There were four boys and three girls and the mean age was 9.5 years. Three patients had lupus vulgaris, three had scrofuloderma, and one child had orificial tuberculosis. Six out of seven children were BCG vaccinated. There was no family history of tuberculosis. The Mantoux reaction was positive in six children. There was no systemic organ involvement in all cases. All patients were treated successfully with triple or quadruple anti-tubercular drugs for 4-11 months. Compared to a previous Tunisian report conducted over an 8-year period in the seventies, the incidence of childhood cutaneous tuberculosis has decreased. In that report, scrofuloderma was the most frequent form. Currently the incidence of lupus vulgaris has reached that of scrofuloderma, demonstrating the increase of the clinical pattern associated with strong immunity. All children had localized disease and responded to antimycobcterial chemotherapy.     

Molecular Epidemiology of Rabies in Wild Canidae in Tunisia

Rabies is a viral zoonosis that is transmissible to humans via domestic and wild animals. There are two epidemiological cycles for rabies, the urban and the sylvatic cycles. In an attempt to study the epidemiological role of wild canidae in rabies transmission, the present study aimed to analyze the genetic characteristics of virus isolates and confirm prior suggestions that rabies is maintained through a dog reservoir in Tunisia. Virus strains isolated from wild canidae were subject to viral sequencing, and Bayesian phylogenetic analysis was performed using Beast2 software. Essentially, the virus strains isolated from wild canidae belonged to the Africa-1 clade, which clearly diverges from fox-related strains. Our study also demonstrated that genetic characteristics of the virus isolates were not as distinct as could be expected if a wild reservoir had already existed. On the contrary, the geographic landscape is responsible for the genetic diversity of the virus. The landscape itself could have also acted as a natural barrier to the spread of the virus.     

弹性蛋白酶和激肽释放酶的联产工艺

本文探讨了利用阴离子交换树脂直接从J_2树脂分离弹性蛋白酶后的母液中吸附胰激肽释放酶,然后经NH_4Ac洗涤和洗脱及丙酮沉淀而获得胰激肽释放酶的最佳工艺路线。每千克猪胰脏平均可得弹性蛋白酶3.09g(纯度为56u/mg),胰激肽释放酶2.72g(纯度为7.44u/mg).胰激肽释放酶回收率为56.6%。     

Complement cascade in severe forms of COVID-19: Recent advances in therapy

The complement system is an essential component of the innate immune system. The three complement pathways (classical, lectin, alternative) are directly or indirectly activated by the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). In the most severe forms of COVID-19, overactivation of the complement system may contribute to the cytokine storm, endothelial inflammation (endotheliitis) and thrombosis. No antiviral drug has yet been shown to be effective in COVID-19. Therefore, immunotherapies represent a promising therapeutic in the immunopathological phase (following the viral phase) of the disease. Complement blockade, mostly C5a-C5aR axis blockade, may prevent acute respiratory distress syndrome (ARDS) from worsening or progression to death. Clinical trials are underway.     

Sodium independence of the binding of [3H]GBR 12783 and other dopamine uptake inhibitors to the dopamine uptake complex

When Na+ was the only cation present in the incubation medium used for the determination of the specific binding of [3H]GBR 12783 in rat striatal membranes, the Na+-dependence between 10 and 210 mM Na+ was not observed. In media with low (10 mM) or high (130 mM) Na+ concentration, mazindol and nomifensine competed with [3H]GBR 12783 for its specific binding site with the same affinities. With the exception of amineptine, all the tested catecholamine uptake inhibitors were equally potent to compete with [3H]GBR 12783 when Na+ concentration was decreased from 130 to 10 mM. These data suggest that the media previously used for the binding studies of tritiated inhibitors of dopamine uptake (Tris-ions buffer and Krebs-Ringer medium) contain ions which could exert inhibitory effects on the specific binding at low Na+ concentration.     

Two new class III G6PD variants [G6PD Tunis (c.920A > C: p.307Gln > Pro) and G6PD Nefza (c.968T > C: p.323 Leu > Pro)] and overview of the spectrum of mutations in Tunisia

We screened 423 patients referred to our laboratory after hemolysis triggered by fava beans ingestion, neonatal jaundice or drug hemolysis. Others were asymptomatic but belonged to a family with a history of G6PD deficiency. The determination of enzymatic activity using spectrophotometric method, revealed 293 deficient (143 males and 150 females). The molecular analysis was performed by a combination of PCR-RFLP and DNA sequencing to characterize the mutations causing G6PD deficiency. 14 different genotypes have been identified : G6PD A^? (376A > G;202G > A) (46.07%) and G6PD Med (33.10%) were the most common variants followed by G6PD Santamaria (5.80%), G6PD Kaiping (3.75%), the association [c.1311T and IVS11 93c] (3.75%), G6PD Chatham (2.04%), G6PD Aures (1.70%), G6PD A^? Betica (0.68%), the association [ 376G;c.1311T;IVS11 93c] (0.68%), G6PD Malaga, G6PD Canton and G6PD Abeno respectively (0.34%). Two novel missense mutations were identified (c.920A > C: p.307Gln > Pro and c.968T > C: p.323 Leu > Pro). We designated these two class III variants as G6PD Tunis and G6PD Nefza. A mechanism which could account for the defective activity is discussed.