Molecular basis of complement factor I deficiency in Tunisian atypical haemolytic and uraemic syndrome patients.

AIM: The aim of the present study was to characterize the molecular basis of complement factor I deficiency in Tunisian atypical haemolytic and uremic syndrome patients with low factor I levels. METHODS: Six adults and seven children were enrolled in this study. Complement factor I levels were assessed by a homemade sandwich ELISA and ranged between 12.5% and 60%. Genomic DNA was amplified by way of a polymerase chain reaction using intronic primers flanking the 13 coding exons. Sequencing of amplified products was carried out by the dye terminator sequencing method. Molecular study was performed on parental samples for three dead paediatric patients. The control group consisted of 100 healthy Tunisian donors. RESULTS: We identified a total of 13 substitutions and one insertion: seven in introns, four in exons and three in UTR. The new mutations were c.-132G > C, c.71 + 181 T > A in 5'UTR and intron 1, respectively. Three intronic polymorphisms were predicted to have impact on splicing events: c.482 + 6C > T, c.884-42_884-41insTTAAA (rs34422850) and c.1429 + 33 A > G (rs9998151). They were three missense mutations leading to a p.Ile 357Met, p.Ile416Leu and p.GLu548Gln. p.Ile 357Met was found in two patients and one relative. Half of the patients had associated mutation and/or polymorphisms. CONCLUSION: This is the first genetic study in Tunisian and Maghrebin atypical haemolytic and uraemic syndrome patients. The high occurrence of Ile357Met mutation may reflect a founding effect. Functional impact of the two new mutations c.-132G > C and c.71 + 181A > T have to be studied. Association of simultaneous genetic abnormalities may explain the variability of atypical haemolytic and uraemic syndrome, penetrance and disease phenotype.

[Post-streptococcal glomerulonephritis in the south of Tunisia: A 12-year retrospective review]. / La glomérulonéphrite aiguë post-streptococcique de l'enfant dans le sud tunisien : étude rétrospective de 12 ans.

AIM: Post-streptococcal glomerulonephritis (PSGN) is a frequent cause of acute nephritis in children. This study aimed to describe the epidemiology, clinical characteristics and outcomes of PSGN and look for predictor's factors of severity. METHODS: A 12-year retrospective review of case notes and laboratory data was conducted at a department of pediatrics, pediatric emergency and intensive care, Hedi Chaker Hospital. RESULTS: One hundred seventy eight children were treated for PSGN with a mean age of 7.6 ans±3.43 ans. One hundred and forty-two patients (80%) had a history of a recent upper respiratory tract or skin infection. Streptococcal pharyngitis was the most common cause, identified in 113 patients (67.6%). Macroscopic hematuria and edema were noted in 135 (75.8%) and 114 cases (64%) respectively. Hypertension was present in 55 patients (31%). Oliguria was noted in 30 children (16.8%). Sixty-six subjects (37%) developed acute renal impairment (creatinine≥70 micromoles/L). No correlation was demonstrated between acute renal impairment and age, sex, triggering infection, anemia and white blood cell count. Creatinine greater than 56.35 micromoles/L was associated with a high risk of developing high blood pressure. The mean length of admission was 5.8 days±4.44. Only one subject has ongoing renal dysfunction. CONCLUSION: PSGN remains a common nephropathy in our region. The detection and effective treatment of any infection that may be involved can reduce the incidence of this disease.

From immunotoxicity to carcinogenicity: the effects of carbamate pesticides on the immune system.

The immune system can be the target of many chemicals, with potentially severe adverse effects on the host's health. In the literature, carbamate (CM) pesticides have been implicated in the increasing prevalence of diseases associated with alterations of the immune response, such as hypersensitivity reactions, some autoimmune diseases and cancers. CMs may initiate, facilitate, or exacerbate pathological immune processes, resulting in immunotoxicity by induction of mutations in genes coding for immunoregulatory factors and modifying immune tolerance. In the present study, direct immunotoxicity, endocrine disruption and inhibition of esterases activities have been introduced as the main mechanisms of CMs-induced immune dysregulation. Moreover, the evidence on the relationship between CM pesticide exposure, dysregulation of the immune system and predisposition to different types of cancers, allergies, autoimmune and infectious diseases is criticized. In addition, in this review, we will discuss the relationship between immunotoxicity and cancer, and the advances made toward understanding the basis of cancer immune evasion.

A minireview on N-acetylcysteine: An old drug with new approaches.

N-acetylcysteine (NAC), a cysteine pro-drug and glutathione precursor has been used in therapeutic practices for several decades, as a mucolytic agent and for the treatment of numerous disorders including paracetamol intoxication. There is a growing interest concerning the beneficial effects of NAC against the early stages of toxicity-induced by pesticides. Nevertheless, the mechanisms underlying the therapeutic and clinical applications of NAC are not fully understood. In this review we aimed to focus on the protective effects of NAC against oxidative stress caused by pesticide in many organs. The possible mechanisms of action may be associated to its antioxidant properties. The anti-oxidative activity of NAC has been attributed to the fast reaction with free radicals as well as the restitution of reduced glutathione (GSH).

Disruption of steroidogenesis after dimethoate exposure and efficacy of N-acetylcysteine in rats: an old drug with new approaches.

Organophosphates (OPs) like dimethoate (DMT), are pesticides used worldwide, which can affect both animals and human. Whereas their toxicity is due to acetylcholinesterase inhibition, their secondary toxic effects have been related to free oxygen radical biosynthesis. The present study was designed to investigate the reprotoxic effects of DMT and the protective role of N-acetylcysteine (NAC) in male rat. DMT (20 mg/ kg/body weight) was administered daily to rats via gavage in corn oil and NAC (2 g/l) was added to drinking water for 30 days. Rats were sacrificed on the 30th day, 2 h after the last administration. Markers of testis injury (steroidogenesis impairment) and oxidative stress (lipid peroxidation, reduced glutathione, and antioxidant status) were assessed. In DMT-exposed rats, the serum level of testosterone was decreased. Further, a significant increase in lipid peroxidation level and a significant decrease in the activities of antioxidant enzymes were observed in the testis of rats during DMT intoxication. Real-time PCR (RT-PCR) analysis demonstrated a decrease in messenger RNA (mRNA) levels for testicular steroidogenic acute regulatory StAR protein, cytochrome P450scc, 3ß-hydroxysteroid dehydrogenase (3ß-HSD), and 17ß hydroxysteroid dehydrogenase (17ß-HSD) in the testis after DMT exposure. No significant changes in the oxidative stress status and selected reproductive variables were observed on CTN group, whereas NAC restored the oxidative stress and the steroidogenesis on NAC group. Dimethoate induces reprotoxicity and oxidative stress. N-acetylcysteine showed therapeutic recovery effects against dimethoate toxicity.

Effects of dimethoate in male mice reproductive parameters.

The aim of the current study was to investigate the ability of dimethoate (DMT) to induce reprotoxicity in male mice. The dose (20 mg/kg/day) was given orally for 30 days. A significant decrease in sperm count, motility and viability and a significant increase of morphologically abnormal spermatozoa percent in DMT treated mice was observed. Testicular Acetylcholinesterase (AChE) and Butyrylcholinesterase (BChE) activities were inhibited. Also, a significant increase in lipid peroxidation level and a significant decrease in the activities of antioxidant enzymes were observed in testis of DMT mice. In addition, gene expression of glutathione peroxidase 4 (GPx4) was quantified in RNA samples extracted from the testis by real-time reverse transcription-polymerase chain reaction (RT-PCR). Compared with control, mRNA expression of GPx4 was slightly decreased after DMT-exposure.

Hepatoprotective and Renoprotective Effects of Lavender (Lavandula stoechas L.) Essential Oils Against Malathion-Induced Oxidative Stress in Young Male Mice.

We aimed in the present study to investigate the hepato- and nephroprotective effects of Lavandula stoechas essential oils (LSEO) against malathion-induced oxidative stress in young male mice as well as the possible mechanism implicated in such protection. Animals were divided into eight groups of 12 each: Control, malathion (200 mg/kg b.w.); Various doses of LSEO (10, 30, and 50 mg/kg b.w.), malathion+various doses of LSEO. Malathion and LSEO were daily per orally (p.o.) administered by intragastric gavage during 30 days. We initially found that malathion treatment induced body weight gain decrease as well as a clear nephro- and hepatotoxicity as assessed by significant relative liver and kidney weight increase and related hemodynamic parameters deregulation. Malathion exposure of mice also induced a considerable perturbation of metabolic parameters. On the other hand, we showed that malathion administration was accompanied by an oxidative stress status assessed by an increase of malondialdehyde (MDA) and hydrogen peroxide (H2O2) levels as well as a depletion of sulfhydril group content (-SH) and antioxidant enzyme activities such as catalase (CAT) and glutathione peroxidase (GPx), total superoxide dismutase (SOD), Cu/Zn-SOD, Mn-SOD, and Fe-SOD in the kidney and liver. More importantly, LSEO treatment abolished all malathion-induced body gain loss, liver and kidney relative weight increase, hemodynamic and metabolic disorders, as well as hepatic and renal oxidative stress. In conclusion, our data suggest that LSEO exerted potential hepato- and nephroprotective effects against malathion-induced oxidative stress in mice. The beneficial effect of LSEO might be related, in part, to its antioxidant properties.

Acute pancreatitis: a rare complication in a patient with senior loken syndrome.

INTRODUCTION: Senior-Loken syndrome is a rare entity that combines familial nephronophthisisand retinal dystrophy. It has an autosomal recessive inheritance pattern and is characterized by a chronic tubulointerstitial nephritis that progress to terminal renal failure during the first or second decades of life. Systemic associations of this syndrome include sensorineural hearing loss, liver fibrosis or cerebral vermis hypoplasia. Acute pancreatitis has not been previously reported in this syndrome. CASE REPORT: This is a 28- years-old patient who was diagnosed to have Senior Loken syndrome at the age of 10 years because of renal impairment and tapetoretinal degeneration and was later started on regular hemodialysis. He had no family history of renal disease, hypertriglyceridemia or cholelithiasis. He presented to our center complaining of acute abdominal pain and vomiting. He had abdominal tenderness without guarding. Investigations revealed a lipase level of 3856 I U/l and an abdominal CT scan showed features of acute pancreatitis. The abdominal ultrasound showed no biliary tree malformations or gallstone obstruction. He had no history of recent drug intake or alcohol consumption and his serum triglyceride level was normal. A diagnosis of moderate acute pancreatitis was made and the patient was managed conservatively with good outcome. CONCLUSION: Taking into consideration the uncertainty about the presence of liver fibrosis and the fact that imaging may have missed a passing gallstone, this case may indicate another rare systemic complication of Senior-Loken syndrome.

Atypical teratoid/rhabdoid tumor of the spine in a 4-year-old girl.

Primary spinal atypical teratoid/rhabdoid tumor is extremely rare. The authors present a case of atypical teratoid/rhabdoid tumor occurring in a 4-year-old girl. Magnetic resonance imaging The authors showed an intramedullary mass extending from the bulbomedullary junction to T1 with leptomeningeal dissemination. The patient died 2 weeks after diagnosis.

Neonatal meningitis by Neisseria meningitidis B.

BACKGROUND: Neisseria meningitidis is one of the major causes of meningitis in children and adolescents, but it is uncommonly found in neonatal meningitis. AIM: to report a rare case of meningitis by Neisseria meningitides B. CASE REPORT: We report the case of neonatal meningitis in a 20-day-old girl without shock or purpura. The symptoms were fever and seizures. The culture of cerebrospinal fluid showed to be positive for Neisseria meningitidis B. culture blood was negative. Antibiotic therapy was started at admission and maintained for 3 weeks. The outcome was favourable without neurological sequelae. CONCLUSION: Early diagnosis and treatment are mandatory for life saving.