Search

North American bison (Bovidae: Bison bison) incur blunt impacts to the interparietal and frontal bones when they engage in head-to-head fights. To investigate the impact mitigation of these bones, a finite element analysis (FEA) of the skull under loading conditions was performed. Based on anatomical and histological studies, the interparietal and frontal bones are both comprised of a combination of haversian and plexiform bone and are both underlain by bony septa. Additionally, the interparietal bone is thicker than the frontal bone. Data regarding the mechanical properties of bison bone are scarce, but the results of a phylogenetic analysis infer that the material properties of the closely related domestic cow bone are a suitable proxy for use in the FEA. Results of the FEA suggest that the thickness of the interparietal bone in conjunction with the bony septa may prevent fracture stresses by helping to absorb and disperse the blunt impact energy throughout the skull. Monotonic stress levels of 294 MPa, which are below the compressive strength of bone were exhibited in the simulated bison head impacts indicating no fracture of the bones., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

Background: Childhood vesico-sphincteric disorders are the cause of functional and psychological disability. They are also responsible for serious uronephrologic complications akin to neuro-bladder complications. In this study, we looked for the clinical manifestations linked to these disorders as well as the paraclinical and urodynamic anomalies and their therapeutic management., Methods: We carried out a retrospective and descriptive study of patients with vesico-sphincteric disorders, followed in the pediatrics department of Charles Nicolle hospital in Tunis., Results: In total 26 patients were included in our study. The median age at the first consultation in a pediatric nephrology department was 9 years (IQR 25 = 6 years; IQR 75 = 11 years). There was a predominance of girls: 19 boys and 43 girls. The filling phase and the voiding phase were dominated by the combination of three or more symptoms. Bladder tenderness was reduced in 12% of cases. Nineteen percent of patients reported post micturition dribble in the post-voiding phase. The flow rate curve was polyphasic in 36% of cases and flat in 11% of cases. The median of the post void residual was 62, 2 mL (IQR 25 = 25 mL; IQR 75 = 102 mL). Cystometry showed reduced bladder sensation in 14% of cases, detrusor overactivity in 65% of cases, bladder hypocontractility in 8% of cases, hypocompliant bladder in 42% of cases and small capacity in 88% of cases. Sphincter dysynergia was noted in 34% of patients. Anticholinergics were the most used in the treatment of disorders (53%). Renal failure was noted in 45% of the patients of which 11% had end-renal stage failure. During follow-up 16% of our patients required kidney replacement therapy., Conclusion: Given the seriousness of vesico-sphincteric disorders in children and the late discovery in the majority of cases at the complication stage, targeted primary prevention must be carried out based on continuous training of primary care physicians to minimize the appearance of complications involving the functional and vital prognosis of these children.

Introduction: Nephronophthisis (NPHP) is a tubulointerstitial kidney disorder with an autosomal recessive inheritance pattern. Its genetic heterogeneity contributes to phenotype variability. The most frequent etiology of juvenile nephronophthisis is a mutation in the nephronophthisis type 1 ( NPHP1 ) gene. This study aimed to evaluate the genotype-phenotype correlation in NPHP1 gene mutation., Methods: A multicenter retrospective study was performed over 20 years from 1998 to 2018 to describe the clinical, biological, and radiological features associated with the large deletion NPHP1 gene in 32 patients., Results: The incidence of NPHP1 was 1.6/204041. Eighty-one percent of our patients were born out of consanguineous marriages. The mean age at diagnosis was 14 ± 7 years. The patients were divided into three groups: isolated nephronophthisis (72%), syndromic nephronophthisis (19%), and patients without recognizable syndrome (9%). Intrafamilial and geographical variability was observed in syndrome diagnoses and in age at the onset of CKD stage 5. Genotype frequency varied between 50% and 100% in genealogical data. Juvenile (47%), adolescent (37%), and adult (13%) clinical forms have been distinguished by the onset of CKD stage 5. The five-year survival rate of renal transplantation was 80%., Conclusion: Given the broad clinical spectrum of NPHP1 associated with the large deletion of the NPHP1 gene, no genotype-phenotype correlation could be established., Competing Interests: There are no conflicts of interest., (Copyright: © 2023 Indian Journal of Nephrology.)

Introduction: Distal renal tubular acidosis (dRTA) is a rare genetic disorder due to the incapacity of the α intercalated cells to excrete protons in the collecting duct. This impaired distal acidification of urine leads to a chronic hyperchloremic metabolic acidosis with a normal plasma anion gap, hypokalemia, and hypercalciuria with hypocitraturia causing nephrocalcinosis. Primary dRTA is inherited either as an autosomal dominant (SLC1A4 gene) or autosomal recessive trait (ATP6V0A1/ATP6V1B1 genes)., Aim: To analyze the genotype-phenotype correlation of dTA in Tunisia., Methods: In this study we present all available data of patients followed in our center for dRTA over the last 28 years and who had a genetic study. This was a retrospective descriptive study from January 1991 to December 2018, conducted in the Pediatrics Department of the Charles Nicolle Hospital in Tunis., Results: Twenty-five cases of dRTA were collected and were offered genetic analysis to confirm the diagnosis. The molecular mutation was confirmed in 13 patients of whom 11 had homozygous mutations in ATP6V1B1(G1) and 2 had homozygous mutations in ATP6V0A4(G2). Median age of diagnosis was 8.9 months. Severe growth retardation was documented in nine children with mutations in ATP6V1B1, in eight children with no genetic mutation and in the two patients with a mutation in ATP6V0A4. All children were found to have metabolic acidosis at initial presentation. Hypokalemia was found in 19 children. All patients were polyuric. Twenty-two patients had nephrocalcinosis (88%). The treatment was based on alkali prescription and substitution of potassium chloride. Sensorineural hearing loss (SNHL) was documented in 12 children. At the last consultation, 14 patients had chronic kidney disease (CKD) stage 2 or higher, 8 of whom were in the group with negative genetic analysis., Conclusion: According to the early onset in patients, the recessive mode seems to be the mode of transmission in Tunisia. dRTA was long considered to not affect renal function, but we note a decline in eDFG.

Background: Nephropathic cystinosis is an autosomal recessive disease caused by a mutation in the CTNS gene which encodes cystinosin, a lysosomal cystine transporter. The spectrum of mutations in the CTNS gene is not well defined in the North African population. Here, we investigated twelve patients with nephropathic cystinosis belonging to eight Tunisian families in order to analyze the clinical and genetic characteristics of Tunisian children with infantile nephropathic cystinosis., Methods: Clinical data were collected retrospectively. Molecular analysis of the CTNS gene was performed by Sanger sequencing., Results: We describe a new splicing mutation c.971-1G > C in the homozygous state in 6/12 patients which seems to be a founder mutation. The reported deletion of 23nt c.771_793 Del (p.Gly258Serfs*30) was detected in a homozygous state in one patient and in a heterozygous compound state with the c.971-1G > C mutation in 3/12 patients. Two of 12 patients have a deletion of exons 4 and 5 of the CTNS gene. None of our patients had the most common 57-kb deletion., Conclusions: The mutational spectrum in the Tunisian population is different from previously described populations. Thus, a molecular diagnostic strategy must be implemented in Tunisia, by targeting as a priority the common mutations described in this country. Such a strategy will allow a cost-effective diagnosis confirmation as well as early administration of treatment with oral cysteamine. A higher resolution version of the Graphical abstract is available as Supplementary information., (© 2022. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae have emerged as important nosocomial pathogens. Community infections by these organisms have been also reported and were associated with previous intestinal colonization. We aimed to characterize cefotaxime-resistant Enterobacteriaceae (CTX-R-En) isolated from hospitalized children in a Tunisian paediatric ward. Seventy CTX-R-En isolates were collected from 227 rectal swabs from hospitalized children in a paediatric ward. Antimicrobial susceptibility testing was determined according to the EUCAST guidelines. Isolates were characterized by polymerase chain reaction (PCR, genes encoding: ESBLs, pAmpC, carbapenemases, plasmid-mediated quinolone resistance, virulence factors in Escherichia coli and Klebsiella pneumoniae isolates, occurrence of classes 1 and 2 integrons, phylogenetic groups of E. coli isolates, ERIC-PCR and PCR-based replicon typing) and conjugal transfer experiments. In total, 65 out of 227 (28·6%) hospitalized children were colonized with CTX-M-R-En, and 70 isolates were identified. Isolates were 59 ESBL-, 7 plasmidic-AmpC (pAmpC)-, 3 ESBL+pAmpC-, and one ESBL+carbapenemase producers. The following bla genes were identified: bla CTX-M-15 (n = 54), bla CTX-M-1 (n = 5), bla CTX-M-9 (n = 2), bla CTX-M-13 (n = 1) and bla CTX-M-14 (n = 1), bla CMY-2 (n = 5), bla CMY-4 (n = 4), bla ACC-1 (n = 1) and bla OXA-48 (n = 1). Our results showed that hospitalized children were colonized with various CTX-R-En-producing several beta-lactamase enzymes., (© 2022 The Society for Applied Microbiology.)

Introduction: The distal renal tubular acidosis of children is characterized by hyperchloremic metabolic acidosis with normal anion gap, hypokalemia, hypercalciuria and nephrocalcinosis. It is secondary to the inability of alpha intercalar cells of the distal tubule to acidify urine of genetic origin., Objective: To analyse the epidemiological aspects of distal tubular acidosis in Tunisia and study its evolutionary profile., Patients and Methods: We conducted a retrospective descriptive study involving 44 patients followed at the paediatrics department of the Charles Nicolle Hospital in Tunis for 28 years (1991-2018)., Results: The most common discovery circumstances were growth retardation (88.6%), dehydration (56.8%), ployuro-polydipsic syndrome (47.7%), vomiting (40.9%) and nephrocalcinosis (38.6%). Growth retardation was found in 52.3% of patients. Dehydration was diagnosed in 59.1% of patients on the first exam. Polyuria was constant with an average diuresis of 8 cc/kg/h. All patients had the complete form of distal renal tubular acidosis with an average alkaline reserve of 11.1 mmol/L. Nephocalcinosis was found in 77.3% associated with nepholithiasis in 22.7%. Twenty-four patients had sensorineural deafness, nine of whom had ATP6V1B1/2p13 mutation. The ATP6V0A4/7q33-34 mutation was present in two patients. We used a high alkaline treatment dose with an average maintenance dose of 8.17 mmol/kg/24 hours. In the long term, stunting persisted in 34% of patients. The mean of creatinine's clearance at the last evaluation was 89.38 mL/min/1.73 m 2 SC with stage 2 of chronic kidney disease in 50% of patients., Conclusion: Distal renal tubular acidosis has long been considered a benign pathology but is responsible for a progressive decline in GFD. Adequate metabolic control is needed to stabilize kidney function., (Copyright © 2022 Société francophone de néphrologie, dialyse et transplantation. Published by Elsevier Masson SAS. All rights reserved.)

Background: Bladder dysfunction may be associated with valves of the posterior urethra. Their evaluation by urodynamic assessment is an important parameter for the therapeutic management. The objective of our study was to study the contribution of urodynamic assessment in the management of valves of the posterior urethra of the child., Methods: Our study was descriptive, retrospective, involving 43 children with posterior urethral valves (PUV), followed at the pediatric ward at Charles Nicolle Hospital in Tunis from January 1995 to December 2015. All the children had an urodynamic assessment after valves of the posterior urethra treatment., Results: The mean age was 15.8 months. Preoperatively, creatinine clearance was below 60 ml / min in 32 patients (74%). The worsening of renal function was noted in 32 (74%). A significant post-voiding residue proved in 34 patients (79%). Cystometry revealed a hypo compliant bladder in 24 (56%), low bladder capacity in 42% of cases; a hypertonic detrusor in 37% of cases. Bladder sphincter dyssynergia was diagnosed in 6 patients. Like urodynamic assessment data, bladder enlargement associated with a Mitrofanoff-type shunt was indicated and performed in 3 patients (7%)., Conclusion: Through our study, the urodynamic profile made it possible to specify the type of vesico-sphincter dysfunctions persistent in patients operated for PUV, and subsequently to adapt the therapeutic conduct in these patients. Given the lack of management and the consequences on the health of the child as well as on his quality of life, reflections on the preventive and therapeutic approach after PUV treatment are necessary.

Introduction: Learning clinical teaching is an alternative to traditional forms of teaching. Its objective is to lead the student to acquire a relevant diagnostic approach by developing a clinical reasoning., Aim: To evaluate these sessions in Pediatrics, with students in the second cycle of medical study., Methods: A session on the topic of "stunting" was scheduled as a CRL with second cycle of medical studies 2 (SCMS2) students during their Pediatrics internship, with a pre and post-test administered and a self-administered questionnaire., Results: Two groups of students that included twenty-three students participated in the session. Pre-test scores ranged from 0/10 to 6.8 / 10 and post-test scores from 6.5 / 10 to 9/10. The average pre- and post-test scores, were respectively 4.26 ± 1.37/10 and 7.35 ± 0.7 / 10 (P <0.001). Twenty-two students reported their overall satisfaction with teaching. The overall rating score was 4.39 ± 0.49/ five points. The average of the ratings for new knowledge delivery, achievement of educational objectives, interaction and participation were greater than 4.3 / 5., Conclusion: This form of small group learning seems to have legitimacy in Pediatric education.

Background: Teaching by the Clarification, Illustration, Application and Participation of Students (CIAP) approach is a method of participatory pedagogy that helps active learning to help the learner understand and integrate the new Knowledge to be able to apply them. The objectives of this work were to describe the conduct of a CIAP session and to evaluate this method of learning among students., Methods: The session took place in a room in the Forensic Medicine Department of the Charles Nicolle Hospital in Tunis on April 18, 2017 for 60 minutes. Our population was made up of DCEM2 students undergoing pediatrics and neonatology at the Charles Nicolle Hospital. The chosen topic was post-infectious acute glomerulonephritis. The assessment consisted in a written test given at baseline before the teaching sessions and repeated immediately afterwards. Students were also asked to grade the quality of the teaching received., Results: In total, 13/22 students were present. Clarifications were given at the request of the students. The illustration showed capillary proliferation and extra-capillary proliferation. Clinical cases have sparked a lot of interaction. All the students participated in the session: seven of them participated actively, the other six were solicited to participate. Pre-test scores varied from 2/10 to 7/10. Post-test scores ranged from 4/10 to 10/10. The mean score for the pre-test was 4.61 ± 1.6 and, the mean score for the post-test was 8.23 ± 2.31 / 10, the difference being statistically significant (p = 0.03). For students, the choices of educational objectives were relevant and were achieved, the session was coherent with the professional reality and brought new knowledge. The majority of students felt that there was good interaction. All students were satisfied with listening to the teacher and her answers to their questions. All students reported that the CIAP session provided them with a better clarification of the theoretical course, a sufficient illustration, and enabled them to participate actively in teaching. The students reported that there was a good application of the theoretical course., Conclusion: The CIAP session improved student knowledge. The students were generally satisfied with this teaching.

Objectives: To evaluate the efficacy and safety of rituximab for treating pediatric systemic lupus erythematosus (pSLE)., Study Design: We performed a systematic review to evaluate the efficacy and safety of rituximab in children with pSLE. Data from studies performed before July 2016 were collected from MEDLINE, the Cochrane Library, Scopus, and the International Rheumatic Disease Abstracts, with no language restrictions. Study eligibility criteria included clinical trials and observational studies with a minimal sample size of 5 patients, regarding treatment with rituximab in patients with refractory pSLE (aged <18 years at the time of diagnosis). Independent extraction of articles was performed by 2 investigators using predefined data fields., Results: Twelve case series met the criteria for data extraction for the systematic review with a good quality assessment according to an 18-criteria checklist using a modified Delphi method. Among them, 3 studies were multicenter and 3 were prospective. The total number of patients was 272. Studies collected patients with active disease refractory to steroids and immunosuppressant drugs. Refractory lupus nephritis was the most common indication (33%). Acceptable evidence suggested improvements in renal, neuropsychiatric and haematological manifestations, disease activity, complement and anti-double stranded Desoxy-Nucleo-Adenosine, with a steroid-sparing effect. However, there was poor evidence suggesting efficacy on arthralgia, photosensitivity, and mucocutaneous manifestations of SLE in children. An overall acceptable safety profile with few major adverse events was shown., Conclusion: Rituximab exhibited a satisfactory profile regarding efficacy and safety indicating that this agent is a promising therapy for pSLE and should be further investigated., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Dyskeratosis congenita (DC) is a very rare inherited disorder. It is caused by dysfunction of telomere maintenance. It involves RNA telomerase components relevant to various mutations leading to a classic triad of physical findings consisting of nail dystrophy of the hands and feet, mucosal leukoplakia, and reticular pigmentation of the skin, most commonly on the head, neck, and trunk. Bone marrow failure along with pulmonary complications and malignancies are all common causes of premature death in patients with DC as well as other abnormalities. We report a new case of DC with impure nephrotic syndrome relevant to histopathologic signs of a diffuse mesangial sclerosis, leading to an early end-stage renal disease. Challenges remain to understand the diverse spectrum of DC especially in children. To the best of our knowledge this is the first case of DC associated to diffuse mesangial sclerosis.

End stage renal disease (ESRD) in infants has particular features in terms of etiologies and therapeutic modalities. The aim of our study is to describe the etiologies and the ESRD outcomes among Tunisian infants. This retrospective study was conducted over 15 years (from January 1998 to December 31, 2013) in the Pediatric Department at Charles Nicolle Hospital. In total, 157 pediatric patients had ESRD. The mean incidence was 4.25 million children. The study involved 24 infants; the sex ratio was equal to 2. The mean age at diagnosis of ESRD was 8 months (range, 1-21 months). Growth retardation was noticed in 14 patients. The main causes were Congenital Anomalies of the Kidneys and Urinary Tract (9 infants) and hereditary renal disease (9 infants). All patients were treated with peritoneal dialysis; 16 infants presented peritonitis. Mortality rate was about 28%. The leading causes of death were cardiovascular diseases and infections., Competing Interests: There are no conflicts of interest.

In this study a woodpecker's hyoid apparatus was characterized to determine its impact mitigation mechanism using finite element (FE) analysis. The woodpecker's hyoid apparatus, comprising bone and muscle, has a unique geometry compared to those of other birds. The hyoid starts at the beak tip, surrounds the woodpecker's skull, and ends at the upper beak/front head intersection while being surrounded by muscle along the whole length. A FE model of the hyoid apparatus was created based on the geometry, microstructure, and mechanical properties garnered from our experimental measurements. We compared the impact mitigation capabilities of the hyoid apparatus with an idealized straight cylinder and a tapered cylinder. The results showed that the hyoid geometry mitigated a greater amount of pressure and impulse compared to the straight or tapered cylinders. The initially applied longitudinal wave lost its strength from attenuation and conversion to transverse shear waves. This is due to the spiral curvature and tapered geometry, which induced lateral displacement in the hyoid bone. The lateral displacement of the bony hyoid induced strains on the adjacent muscle, where the energy dissipated due to the muscle's viscoelasticity. Quantitatively, as the stress wave traveled from the anterior to the posterior end of the hyoid apparatus, its pressure decreased 75% and the associated impulse decreased 84%. The analysis of the woodpecker's hyoid apparatus provides a novel perspective on impact mitigation mediated by a spiral-shaped structure and viscoelastic biocomposite.

Background - Most patients with idiopathic nephrotic syndrome are steroid-responsive, about 50% relapse and often become steroid-dependent and exposed to long-term steroid complications. The aim of this study was to determine predictive risk factors for steroid dependence using clinical and biological variables present at onset of the disease. It may be useful to adapt the therapeutic strategy. Methods - Retrospective hospital-based cohort study in the department of pediatric nephrology of Charles Nicolle, Tunis, between 2002 and 2012 included 52 children with idiopathic steroid-responsive nephrotic. Results - Risk factors for steroid dependency identified from univariate analysis were season of the first episode (winter or autumn) (p=0.008), hyperalpha2globulinemia>16g/l (p=0.028), hyperbeta2globulinemia >3g/l (p=0.003), hypercholesterolemia>10mmol/l (p=0.001), proteinuria>110mg/kg/day (p=0.05), time to achieve remission>9 days (p=0,0001). Logistic regression revealed that time to first remission and hypercholesterolemia>10mmol/l at first presentation were independent risk factors for steroid dependency. Conclusion - Time to first remission, hypercholesterolemia more than 10mmol/l at first presentation and a respiratory tract infection at first relapse are independent risk factors for steroid dependency.

Background: The end-stage renal disease (ESRD) in children has special features in terms of etiologies, therapeutic modalities and access to renal transplantation. In Tunisia, there are no data on the epidemiology of ESRD in children. The aim of our study was to describe epidemiology of ESRD among Tunisian children., Methods: This retrospective study was conducted in pediatric departments in Charles-Nicolle Hospital, Tunis and Hedi Chaker hospital, Sfax, during a period of 15 years (1st January 1998-31st December 2013). We included children who develop ESRD before the age of 15 years., Results: In total, 166 patients were included. The median duration of follow-up was 48 months. We collected respectively 24 children (14.5%) aged less than 2 years, 24 children (14.5%) aged between 2 and 6 years and 118 children (71%) older than 6 years. The sex ratio was equal to 1.4. The mean incidence was 4.25 cases per million children. The main causes were represented by congenital anomalies of the kidneys and urinary tract (35.5%), hereditary renal disease (31.3%) and glomerular kidney disease (9.6%). All patients were treated in kidney transplant dialysis programs; the main mode of dialysis was represented by peritoneal dialysis, which represented the initial dialysis mode in 81% of cases. The transition to hemodialysis was noted in 43.4% cases. Thirty-eight patients (22.8%) were transplanted. The mortality rate was 27.1%. The leading cause of death was cardiovascular diseases (37.7%) and infections (22.2%)., Conclusion: The creation of a national registry of kidney disease in Tunisia is necessary for a better knowledge of needs for dialysis and renal transplantation in children., (Copyright © 2015 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.)

Background - Vesicoureteral reflux (VUR) is a common pediatric urologic disorder. After the first urinary tract infection (UTI), imaging studies are recommended, starting with a renal ultrasound (US) and voiding cystourethrography (VCUG). We propose to determine whether abnormalities found on US can help indicate the necessity of VCUG in children after the first urinary tract infection. Methods - A retrospective study included all children admitted with their first episode of urinary tract infection from January 2007 to December 2012. Results - A total of 311 children were included. The median age was 2.5 years, 72.3% were female. VUR Prevalence was 14%.  Forty-four patients were found to have VUR on VCUG, giving a prevalence of 14%. Of these 44 patients, 11 had grade I reflux, 6 had grade II reflux, 3 had grade III reflux, 15had grade IV reflux, and 9 had grade V reflux. Ultrasound findings were positive for VUR in 43 patients, 19 of them had RVU. Twenty five patients had a normal ultrasound but showed VUR on VCUG (11 had grade I reflux, six grade II reflux, three grade III reflux and five grade IV reflux).  The sensitivity and specificity of ultrasound in suggesting VUR were 43% and 91%, respectively. The positive predictive value of ultrasound in suggesting VUR was 44%; the negative predictive value was 91%. Conclusion - Renal ultrasound findings are specific for VUR in children with a first UTI, but no sensitive. Clinicians should consider renal ultrasound results to take decision on whether or not to proceed with a VCUG in the investigation of a first episode UTI in young children.

Introduction Peritoneal dialysis (PD) is still the most common modality used in treatment for children with End Stage Renal Disease (ESRD). The objective of this study was to identify the epidemiological, clinical, and microbiological factors affecting the outcome of PD. Methods In this study, we retrospectively reviewed the records of 85 patients who were treated with DP for the last ten years (from January 2004 to December 2013) in the Department of Pediatrics in Charles Nicolle hospital, Tunis. Results The mean duration of PD was 18.1±12 months (3.5-75 months). The average age of PD onset was 9.3±5.7 years (29 days-23 years). The sex ratio was 1.5. In a significant number of cases with ESRD, the primary cause is Congenital Anomalies of the Kidneys and Urinary Tract (CAKUT). Seventy-four of our patients (87%) had been treated with Automated PD. The average time between catheter placement and PD commencement was 3.9±4.6 days. Catheter change was 1.62 (1-5). Sixty-one patients (71.8%) had experienced at least one episode of peritonitis. The most frequently isolated organisms was the Gram-positive bacteria (61%). Survival rates without peritonitis at 12th, 24th and 36th months were 40%, 32% and 18%, respectively. Transition to permanent hemodialysis was required in 66% of patients. Conclusion Considering the important incidence of peritonitis in our patients, it is imperative to establish a targeted primary prevention.

Background Focal segmental glomerulosclerosis (FSGS) represents 20% of nephrotic syndrome in children. The clinical course and prognosis is heterogeneous in children. The aim of this study was to analyze treatment and outcome of children with FSGS. Methods This retrospective study was conducted in the Department of Pediatrics in Charles Nicolle Hospital during a 15-year period (1996-2010). Results There were 30 children, 16 boys and 14 girls. The mean age was 7 ± 4 years. Nephrotic syndrome was observed in 26 patients, hematuria was noticed in 2 patients and renal insufficiency was detected in 2 patients at presentation. FSGS, not otherwise specified, was the predominant variant. All patients with nephrotic syndrome were treated with steroids. Only three patients responded to it. Twenty one patients were treated with cisclosporin A and this resulted in a 57% complete remission and a 24% partial response. Cyclophosphamide was administered to 6 patients and engendered a 50% complete remission. Six patients were treated with mycophenolate mophetil and showed no response in all cases. Renal insufficiency has been developed in 12 children. Conclusion Results from this study showed that the majority of children with FSGS achieve a high sustained remission rate with ciclosporine A.

Background Nephrocalcinosis is rare in children. Its etiologies are multiple. The aim of this study was to analyze the etiology of nephrocalcinosis in Tunisian children. Methods This retrospective study was conducted in the department of pediatrics in Charles Nicolle Hospital during a period of 10 years (2001-2010). Results There were 40 children. The mean age was 3.5 years. The most common signs and symptoms at presentation were growth retardation (42.5%) and hematuria (53.8%). At presentation, renal failure was detected in 70% of patients. The diagnosis of nephrocalcinosis was performed by ultrasonography. The etiology of nephrocalcinosis included primary hyperoxaluria type 1 (65%) and distal renal tubular acidosis (20%). A progression to renal insufficiency was observed in 18 cases. Conclusion Primary oxaluria is the principal cause of nephrocalcinosis; early diagnosis and treatment are mandatory as they help limiting renal function deterioration.

Objectives: To establish the efficacy of mycophenolate mofetil (MMF) in steroid dependent nephrotic syndrome and to determine the predictive factors for a good response., Methods: retrospective hospital-based cohort study in the department of pediatric of Charles Nicolle hospital, between 2005 and 2012 included 30 children with steroid-dependent nephritic syndrome who were treated with MMF., Results: A total of 30 patients (20 boys and 10 girls) were included. The mean age at the time of diagnosis was 5.45 years and treatment with MMF was performed at a mean age of 10.84 years. Side effects of steroid were found in 17 patients. Four patients had renal impairment (ciclotoxicity). The evolution of the disease was 5.45 years. The average rate of relapse was 1.75 relapses / year. The minimum dose of corticosteroids was 0.74 mg / kg / day. During MMF therapy, the average rate of relapse was 0.45 relapses / year (p<0.0001). The average residual steroid dose was 0.2 mg/kg/ day. Responding patients were younger at the onset of MMF (8.57 versus 12.83, p=0.009), had a short development period (3.75 vs 7.03 years, p=0.05), had not received cyclosporine (p=0.02)., Conclusion: MMF allows steroid sparing and reduces the number of relapse. It is more effective than the patients are young, with short disease outcome and had not previously been treated with cyclosporine.

Background: Peritonitis on catheter of dialysis represents the most frequent complication of the peritoneal dialysis (PD) in the pediatric population. It remains a significant cause of morbidity and mortality. In this study, we investigated the risk factors for peritonitis in children., Methods: In this study, we retrospectively collected the records of 85 patients who were treated with PD within the past ten years in the service of pediatrics of the University Hospital Charles-Nicolle of Tunis., Results: Peritonitis rate was 0.75 episode per patient-year. Notably, peritonitis caused by Gram-positive organisms were more common. Analysis of infection risk revealed three significant independent factors: the poor weight (P=0.0045), the non-automated PD (P=0.02) and the short delay from catheter insertion to starting PD (P=0.02). The early onset peritonitis was significantly associated with frequent peritonitis episodes (P=0.0008). The mean duration between the first and second episode of peritonitis was significantly shorter than between PD commencement and the first episode of peritonitis. We revealed a significant association between Gram-negative peritonitis and the presence of ureterostomy (0.018) and between Gram-positive peritonitis and the presence of exit-site and tunnel infections (0.02). Transition to permanent hemodialysis was needed in many children but no death occurred in patients with peritonitis., Conclusion: Considering the important incidence of peritonitis in our patients, it is imperative to establish a targeted primary prevention. Nutritional care must be provided to children to avoid poor weight. The automated dialysis has to be the modality of choice., (Copyright © 2015 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.)

Recipients of solid organ transplantation are, because of immunosuppressive therapy, at high risk to develop opportunistic infections including tuberculosis (TB). The incidence, clinical manifestations, and optimal diagnostic tests of this disease in this population have not been adequately defined. In this paper, we report a case of 13 year-old boy who developed pulmonary tuberculosis following a second renal transplantation from a deceased donor. The described case points diagnostic difficulties of the tuberculosis disease which are due to insidious and non specific clinical presentation. Also, the treatment is delicate because interaction between immunosuppressive drugs and antituberculosis drugs.

Williams-Beuren syndrome is a rare neurodevelopmental disorder, characterized by congenital heart defects, abnormal facial features, mental retardation with specific cognitive and behavioral profile, growth hormone deficiency, renal and skeletal anomalies, inguinal hernia, infantile hypercalcaemia. We report a case with Williams-Beuren syndrome associated with a single kidney and nephrocalcinosis complicated by hypercalcaemia. A male infant, aged 20 months presented growth retardation associated with a psychomotor impairment, dysmorphic features and nephrocalcinosis. He had also hypercalciuria and hypercalcemia. Echocardiography was normal. DMSA renal scintigraphy showed a single functioning kidney. The FISH generated one ELN signal in 20 metaphases read and found the presence of ELN deletion, with compatible Williams-Beuren syndrome.

Background: Rapidly progressive glomerulonephritis is a rare form of postinfectious glomerulonephritis. The aim of this study was to describe the outcome of our patients with severe post-streptococcal glomerulonephritis., Methods: This retrospective study was conducted in the department of pediatrics in Charles-Nicolle Hospital during a period of 13 years (1997-2009)., Results: Twenty-seven children were identified. The mean age was 8.7 years. All patients presented renal failure at presentation. The mean serum creatinine at presentation was 376.9 μmol/L. Six patients presented nephrotic syndrome. Twenty-six children had renal biopsies. Renal biopsies showed crescents in 24 cases. Eighteen children received pulse dose of corticosteroids (66.6%) and 6 children (22%) received pulse dose of corticosteroids and cyclophosphamide. Eleven patients required dialysis. At last follow-up, 22 patients (81.5%) had normal kidney function, 2 had renal dysfunction and 3 reached end stage renal disease. The only significant determinant for renal survival was the supportive dialysis (P=0.015)., Conclusion: Rapidly progressive glomerulonephritis is uncommon. There have been significant advancements in supportive, as well as specific therapy, but the outcome continues to be poor., (Copyright © 2015 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.)

The turtle's shell acts as a protective armor for the animal. By analyzing a turtle shell via finite element analysis, one can obtain the strength and stiffness attributes to help design man-made armor. As such, finite element analysis was performed on a Terrapene carolina box turtle shell. Experimental data from compression tests were generated to provide insight into the scute through-thickness behavior of the turtle shell. Three regimes can be classified in terms of constitutive modeling: linear elastic, perfectly inelastic, and densification regions, where hardening occurs. For each regime, we developed a model that comprises elasticity and densification theory for porous materials and obtained all the material parameters by correlating the model with experimental data. The different constitutive responses arise as the deformation proceeded through three distinctive layers of the turtle shell carapace. Overall, the phenomenological stress-strain behavior is similar to that of metallic foams., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Background: Anti-GBM disease is a rare vasculitis mediated by pathogenic antibodies against collagen IV. Anti-GBM disease presents with rapid progressive glomerulonephritis and leads to kidney failure if untreated. KDIGO recommends plasma exchanges (PEX) for antibody elimination and steroids plus cyclophosphamide (CTX) to suppress antibody production. CTX is associated with severe side effects including gonadal toxicity. Rituximab (RTX) and mycophenolate mofetil (MMF) might be a less toxic but equally efficient alternative to CTX. Studies in pediatric anti-GBM disease patients receiving RTX and MMF instead of CTX are lacking., Methods: A retrospective survey in 8 tertiary German centers was performed. The clinical data of patients diagnosed between 2014 and 2022 were collected and analyzed., Results: Five adolescent patients treated with PEX and RTX and/or MMF due to anti-GBM disease were analyzed. All patients had anti-GBM antibodies, hematuria, glomerular proteinuria, and pulmonary hemorrhage. eGFR was 124 ml/min/1.73 m 2 (range 47-162), and all patients were non-dialysis-dependent but with relevant histological kidney affection (mean crescents on kidney biopsy 77%). Antibody clearance was achieved after 13 PEX cycles (range 6-31). Four out of 5 patients received methylprednisolone pulses. All patients received oral prednisolone and MMF, and four patients received a median of 4 RTX doses (range 2-4). After a mean follow-up of 27 months, 4/5 patients had conserved or improved kidney function, while one patient (20%) developed kidney failure., Conclusions: In this small series of pediatric non-dialysis-dependent anti-GBM disease patients, first-line treatment with RTX and MMF showed a favorable kidney outcome in 4/5 cases and had an acceptable side effect profile., (© 2024. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

The biomechanics of woodpeckers have captivated researchers for decades. These birds' unique ability to withstand repeated impacts, seemingly without apparent harm, has piqued the interests of scientists and clinicians across multiple disciplines. Historical and recent studies have dissected the anatomical and physiological underpinnings of woodpeckers' protective mechanisms and sparked interest in the development of woodpecker-inspired safety equipment. Despite the intuitive appeal of translating woodpecker adaptations into strategies for human traumatic brain injury (TBI) prevention, significant challenges hinder such innovation. Critical examinations reveal a lack of direct applicability of these findings to human TBI prevention, attributed to fundamental biological and mechanical dissimilarities between humans and woodpeckers. Additionally, some commercial endeavors attempting to capitalize on our fascination with woodpeckers are rooted in unsubstantiated claims about these birds. This paper explores the narrative surrounding woodpecker biomimicry, including its origins and history, and highlights the challenges of translating findings from unconventional animal models of TBI into effective human medical interventions., (© 2024 American Association for Anatomy.)

Background: Peritonitis is the leading cause of peritoneal dialysis (PD) discontinuation. However, few data concern risk factors of peritonitis development and catheter removal caused by treatment failure in pediatric patients., Methods: This single-center, retrospective study analyzed data from pediatric patients who underwent chronic PD between March 2002 and June 2022. The incidence rates of peritonitis by the person-year method were calculated, and they were stratified by patient age groups. Risk factors for peritonitis development and catheter removal were also analyzed by multivariate analysis using logistic regression model., Results: Ninety patients were enrolled, and 62 peritonitis episodes were observed in 41 (46%) patients. The incidence rate of peritonitis was 0.21 episodes per patient-year, which was the highest in children aged under 2 years old (0.26 episodes per patient-year). Moreover, 44 (71%) cases were successfully cured by antibiotics alone, although 17 (27%) cases required catheter removal, and 4 (6%) cases transitioned to chronic hemodialysis because of peritoneal dysfunction. One patient died. The risk factor for peritonitis development and catheter removal caused by treatment failure was PD insertion at under 2 years old (odds ratio = 2.5; P = 0.04) and Pseudomonas aeruginosa (odds ratio = 11.0; P = 0.04) in the multivariate analysis. P. aeruginosa was also a risk factor for difficulty in re-initiating PD (P = 0.004)., Conclusions: The incidence rate of peritonitis was the highest in children under 2 years old. P. aeruginosa peritonitis is a risk factor for catheter removal and peritoneal dysfunction., (© 2024. The Author(s), under exclusive licence to Japanese Society of Nephrology.)

In this paper, the microstructure characteristics and mechanical properties (including nano-indentation, tensile, and penetration behaviors) of the scales from pinecone fish (Monocentris japonica) were investigated. The M. japonica scales display a unique hierarchical structure and consist of three layers: an outer bone layer with high mineralization, an intermediate bone layer with obvious pore structures, and an inner collagen layer composed of multiple plies of collagen fibers. The hardness and indentation modulus of the three structural layers exhibit gradient changes, and decrease gradually from the outer layer to the inner layer. Tensile tests show that the tensile response and failure modes of the scales are different under dry and hydrated conditions. The dry scales have higher tensile strength (46.35 MPa) and Young's modulus (0.74 GPa), while the hydrated scales exhibit higher ultimate strain (20.18%) and toughness (4.57 MPa). Penetration tests indicate that the scales have a significantly high resistance to penetration, and increase the penetration force by more than six times compared with the descaled skin. Furthermore, the structure-property relationship of the M. japonica scales was discussed. It is found that the hard outer layer and the porous intermediate layer help to disperse the stress, and the soft inner layer containing collagen fiber plies helps to deflect the crack propagation, which are responsible for the excellent mechanical properties of the scales. The outcome of this study can provide a valuable biomimetic design inspiration for lightweight and high-strength composite materials in engineering fields. RESEARCH HIGHLIGHTS: Microstructure characteristics and mechanical properties of the Monocentris japonica scales were investigated. The M. japonica scales can be divided into three layers rather than two layers. The M. japonica scales exhibited high tensile strength and penetration resistance., (© 2023 Wiley Periodicals LLC.)

The clinical impact of infections due to extended-spectrum β-lactamase (ESBL)- and/or carbapenemase-producing Enterobacterales (Ent) has reached dramatic levels worldwide. Infections due to these multidrug-resistant (MDR) pathogens-especially Escherichia coli and Klebsiella pneumoniae-may originate from a prior asymptomatic intestinal colonization that could also favor transmission to other subjects. It is therefore desirable that gut carriers are rapidly identified to try preventing both the occurrence of serious endogenous infections and potential transmission. Together with the infection prevention and control countermeasures, any strategy capable of effectively eradicating the MDR-Ent from the intestinal tract would be desirable. In this narrative review, we present a summary of the different aspects linked to the intestinal colonization due to MDR-Ent. In particular, culture- and molecular-based screening techniques to identify carriers, data on prevalence and risk factors in different populations, clinical impact, length of colonization, and contribution to transmission in various settings will be overviewed. We will also discuss the standard strategies (selective digestive decontamination, fecal microbiota transplant) and those still in development (bacteriophages, probiotics, microcins, and CRISPR-Cas-based) that might be used to decolonize MDR-Ent carriers., (© 2023. The Author(s).)

High-dose steroids are required for the treatment of minimal change nephrotic syndrome (MCNS), especially for episodes of recurrence. Predicting and avoiding recurrence can help reduce the steroid dose, but prediction is currently difficult. We herein examined whether changes in laboratory data, especially the urinary protein- to-creatinine ratio (UTP/UCr), can predict clinical recurrence. We also assessed differences in clinical features between children and young adults. We included 36 patients with MCNS; for each case, we retrospectively studied laboratory data during stable remission and pre-recurrence, with the "stable" period defined as all but the 6 weeks before recurrence, and pre-recurrence defined as the 4±2 weeks before recurrence. UTP/UCr, serum albumin, etc. were measured every 5 years during stable periods. We divided patients into cohorts by age at recurrence, < 15 years and ≥ 15 years, and compared stable and pre-recurrence values for the two groups. UTP/UCr values during stable periods tended to be higher in younger patients. UTP/UCr and serum albumin showed statistically significant changes during pre-recurrence periods, but only in those aged ≥ 15 years. Thus, clinical features of recurrence differed depending on age. Signs of recurrence can be confirmed via UTP/UCr or serum albumin several weeks before recurrence in patients ≥ 15 years., Competing Interests: No potential conflict of interest relevant to this article was reported.

Background: Nephrocalcinosis (NC) is defined as calcium deposition in the kidney parenchyma and tubules. This study aims to determine the etiology, risk factors, and follow-up results of patients with NC in Turkey., Methods: Patients diagnosed with NC in the pediatric nephrology Department Units of 19 centers from all geographical regions of Turkey over a 10-year period (2010-2019) were included in the study. The medical records from the centers were reviewed and demographic data, admission complaints, medical history, systemic and genetic disorders, risk factors for NC, treatment details, and presence of NC after one-year follow-up, were recorded retrospectively., Results: The study sample included 195 patients (88 females, 107 males). The mean age at diagnosis was 39.44 ± 47.25 (0.5-208) months; 82/190 patients (43.2%) were diagnosed incidentally; 46/195 patients (23.6%) had an underlying disease; idiopathic hypercalciuria was detected in 75/195 (38.4%) patients. The most common systemic diseases were distal renal tubular acidosis in 11/46 patients (23.9%), primary hyperoxaluria in 9/46 patients (19.6%) and Bartter syndrome in 7/46 patients (15.3%). After one year of follow-up, NC resolved in 56/159 patients (35.2%) and they all did not have an underlying systemic disease., Discussion: The most common presentation of NC was incidental. Distal renal tubular acidosis and primary hyperoxaluria were the main systemic diseases leading to NC, while hypercalciuria was the most common metabolic risk factor. Nephrocalcinosis was found to remain in most of the patients at a one-year follow-up. It may resolve particularly in patients with no underlying systemic disease.