Transition to oral antibiotic therapy for pyelonephritis in children under 60 days of age: An observational retrospective cohort study.

OBJECTIVES: To describe the use of antibiotics and assess if an early transition from intravenous to oral antibiotic therapy is generally safe in infants less than 60 days of age with a diagnosis of pyelonephritis. METHODS: This retrospective observational cohort study included hospitalized infants less than 60 days with a diagnosis of pyelonephritis based on fever or systemic symptoms and a positive urine culture between January 1, 2015 and July 30, 2017 at a Canadian paediatric tertiary care centre. RESULTS: A total of 108 infants were included. Forty-eight of them were under 1 month of age. The median intravenous (IV) antibiotic therapy duration was 3.5 days, with a longer duration of 4 days in infants less than 1 month of age. The total antibiotic therapy was almost equally divided between a shorter (10 days) and longer (14 days) duration. The recurrence of pyelonephritis within the 2 months following the initial urinary infection was 9 % in the group with IV antibiotic therapy duration of <4 days, compared to 11% in the group treated ≥4 days IV (P-value 0.75). There was a recurrence of pyelonephritis of 10.2% in the group treated for 10 days, compared to 11.5% of recurrence in the group treated for 14 days (P-value 1.0). CONCLUSIONS: Our study provides limited retrospective data regarding the management of pyelonephritis in infants less than 60 days of age. Prospective research is needed to confirm those findings.

The Québec NTBC Study.

In this chapter we describe the current Quebec NTBC Study protocol. Quebec's unique characteristics have influenced the development of the protocol, including a high prevalence of hepatorenal tyrosinemia (HT1), universal newborn screening for HT1, availability of treatment with nitisinone (NTBC) and special diet, a large territory, where HT1 treatment is coordinated by a small number of centers. Screened newborns are seen within 3 weeks of birth. Patients with liver dysfunction (prolonged prothrombin time and/or international normalized ratio (INR) provide sensitive, rapidly available indicators) are treated by NTBC and special diet. The specific diagnosis is confirmed by diagnostic testing for succinylacetone (SA) in plasma and urine samples obtained before treatment. After an initial period of frequent surveillance, stable patients are followed every 3 months by assay of plasma amino acids and NTBC and plasma and urine SA. Abdominal ultrasound is done every 6 months. Patients have an annual visit to the coordinating center that includes multidisciplinary evaluations in metabolic genetics, hepatology, imaging (for abdominal ultrasound and magnetic resonance imaging) and other specialties as necessary. If hepatocellular carcinoma is suspected by imaging and/or because of progressive elevation of alphafetoprotein, liver transplantation is discussed. To date, no patient in whom treatment was started before 1 month of age has developed hepatocellular carcinoma, after surveillance for up to 20 years in some. This patient group is the largest in the world that has been treated rapidly following newborn screening. The protocol continues to evolve to adapt to the challenges of long term surveillance.

Increased Epithelial Gap Density in the Noninflamed Duodenum of Children With Inflammatory Bowel Diseases.

OBJECTIVES: Inflammatory bowel diseases (IBD) present commonly in childhood, with unknown etiology, but an important role for the epithelial lining is suggested. Epithelial cell extrusion, measured by counting gaps between epithelial cells, is higher in adult patients with Crohn disease (CD) than in controls. Our objectives were to compare epithelial gaps in the duodenum of IBD and non-IBD pediatric patients, to study the correlation between epithelial gaps, inflammation, and disease activity, and identify potential mechanisms. METHODS: Epithelial gap density of the duodenum was evaluated using probe-based confocal laser endomicroscopy in 26 pediatric patients with IBD (16 CD, 10 ulcerative colitis [UC]) and 17 non-IBD controls during endoscopy. Epithelial gaps were correlated with serum inflammatory markers, disease activity indices, and intraepithelial lymphocytes. A panel of 10 inflammatory cytokines and expression of TNFAIP3 (A20; inhibits NF-κß-induced inflammation) were analyzed in duodenal and ileal biopsies. RESULTS: Confocal imaging showed significantly higher epithelial gap density in patients with IBD, including UC. Interleukin (IL)-2 and IL-8 were higher in duodenal but not ileal biopsies of patients with UC. No significant correlation was present between C-reactive protein, erythrocyte sedimentation rate, disease activity indices, and epithelial gaps in patients with UC. In patients with CD, C-reactive protein positively correlated with epithelial gaps. A20 expression in the duodenum was unchanged among non-IBD and IBD cases. CONCLUSIONS: Duodenal epithelial gaps are increased in pediatric patients with IBD (including UC) but are unrelated to inflammation. This suggests that altered epithelial barrier is an important systemic feature of pediatric IBD and is not only secondary to inflammation.

Breaks in the wall: increased gaps in the intestinal epithelium of irritable bowel syndrome patients identified by confocal laser endomicroscopy (with videos).

BACKGROUND: Altered intestinal permeability and mucosal inflammation have been reported in irritable bowel syndrome (IBS) patients. Increased cell extrusion in the epithelium as measured by epithelial gaps may be associated with barrier dysfunction and may lead to mucosal inflammation. Confocal laser endomicroscopy can be used to identify and quantitate epithelial gaps in the small intestine. OBJECTIVE: To determine the epithelial gap density in IBS and healthy control patients. DESIGN: Prospective, controlled cohort study. SETTING: A tertiary referral center. PATIENTS: In IBS and control patients undergoing routine colonoscopy, probe-based confocal laser endomicroscopy was used to image the terminal ileum. MAIN OUTCOME MEASUREMENTS: The primary outcome was the density of epithelial gaps (gaps/cells counted) in adequately imaged villi using pCLE. Images were reviewed by 2 blinded reviewers. RESULTS: We recruited 18 healthy controls and 16 IBS patients. The median epithelial gap densities for control and IBS patients were 6 and 32 gaps per 1000 cells, respectively (P < .001). There was a trend toward higher gap density in female (P = .07) and younger (ρ = -0.43, P = .07) patients. Using 3% (90% of the control population) as the cutoff for abnormal gap density, we found the diagnostic accuracy for IBS to be as follows: 62% sensitivity, 89% specificity, 83% positive predictive value, and 73% negative predictive value. LIMITATIONS: A single-center study, small number of patients. CONCLUSIONS: IBS patients have significantly more epithelial gaps in their small intestine compared with healthy controls, which suggests that increased epithelial cell extrusion may be a cause of altered intestinal permeability observed in IBS.

Increased epithelial gaps in the small intestine are predictive of hospitalization and surgery in patients with inflammatory bowel disease.

OBJECTIVES: Epithelial gaps resulting from intestinal cell extrusions can be visualized with confocal laser endomicroscopy (CLE) during colonoscopy and increased in normal-appearing terminal ileum of inflammatory bowel disease (IBD) patients. Cell-shedding events on CLE were found to be predictive of disease relapse. The aim of this study was to assess the prognostic value of epithelial gap densities for major clinical events (hospitalization or surgery) in follow-up. METHODS: We prospectively followed IBD patients undergoing colonoscopy with probe-based CLE (pCLE) for clinical events including symptom flares, medication changes, hospitalization, or surgery. Survival analysis methods were used to compare event times for the composite outcome of hospitalization or surgery using log-rank tests and Cox proportional hazards models. We also examined the relationship of gap density with IBD flares, need for anti-tumor necrosis factor therapy, disease duration, gender and endoscopic disease severity, and location. RESULTS: A total of 21 Crohn's disease and 20 ulcerative colitis patients with a median follow-up of 14 (11-31) months were studied. Patients with elevated gap density were at significantly higher risk for hospitalization or surgery (log-rank test P=0.02). Gap density was a significant predictor for risk of major events, with a hazard ratio of 1.10 (95% confidence interval=1.01, 1.20) associated with each increase of 1% in gap density. Gap density was also correlated with IBD disease duration (Spearman's correlation coefficient rho=0.44, P=0.004), and was higher in male patients (9.0 vs. 3.6 gaps per 100 cells, P=0.038). CONCLUSIONS: Increased epithelial gaps in the small intestine as determined by pCLE are a predictor for future hospitalization or surgery in IBD patients.

raf RBD and ubiquitin proteins share similar folds, folding rates and mechanisms despite having unrelated amino acid sequences.

Recent experimental and theoretical studies in protein folding suggest that the rates and underlying mechanisms by which proteins attain the native state are largely determined by the topological complexity of a specific fold rather than by the fine details of the amino acid sequences. However, such arguments are based upon the examination of a limited number of protein folds. To test this view, we sought to investigate whether proteins belonging to the ubiquitin superfamily display similar folding behavior. To do so, we compared the folding-unfolding transitions of mammalian ubiquitin (mUbi) with those of its close yeast homologue (yUbi), and to those of the structurally related Ras binding domain (RBD) of the serine/threonine kinase raf that displays no apparent sequence homology with the ubiquitin family members. As demonstrated for mUbi [Krantz, B. A., and Sosnick, T. R. (2000) Biochemistry 39, 11696-11701], we show that a two-state transition model with no burst phase intermediate can describe folding of both yUbi and raf RBD. We further demonstrate that (1) all three proteins refold at rates that are within 1 order of magnitude (1800, 1100, and 370 s(-1) for mUbi, raf RBD, and yUbi, respectively), (2) both mUbi and raf RBD display similar refolding heterogeneity, and (3) the folding free energy barriers of both mUbi and raf RBD display a similar temperature dependence and sensitivity to a stabilizing agent or to mutations of a structurally equivalent central core residue. These findings are consistent with the view that rates and mechanisms for protein folding depend mostly on the complexity of the native structure topology rather than on the fine details of the amino acid sequence.

Polymorphism, shared functions and convergent evolution of genes with sequences coding for polyalanine domains.

Mutations causing expansions of polyalanine domains are responsible for nine hereditary diseases. Other GC-rich sequences coding for some polyalanine domains were found to be polymorphic in human. These observations prompted us to identify all sequences in the human genome coding for polyalanine stretches longer than four alanines and establish their degree of polymorphism. We identified 494 annotated human proteins containing 604 polyalanine domains. Thirty-two percent (31/98) of tested sequences coding for more than seven alanines were polymorphic. The length of the polyalanine-coding sequence and its GCG or GCC repeat content are the major predictors of polymorphism. GCG codons are over-represented in human polyalanine coding sequences. Our data suggest that GCG and GCC codons play a key role in polyalanine-coding sequence appearance and polymorphism. The grouping by shared function of polyalanine-containing proteins in Homo sapiens, Drosophila melanogaster and Caenorhabditis elegans shows that the majority are involved in transcriptional regulation. Phylogenetic analyses of HOX, GATA and EVX protein families demonstrate that polyalanine domains arose independently in different members of these families, suggesting that convergent molecular evolution may have played a role. Finally polyalanine domains in vertebrates are conserved between mammals and are rarer and shorter in Gallus gallus and Danio rerio. Together our results show that the polymorphic nature of sequences coding for polyalanine domains makes them prime candidates for mutations in hereditary diseases and suggests that they have appeared in many different protein families through convergent evolution.

Intracerebral aneurysms: a review with special attention to geriatric aspects.

Rupture of an intracranial aneurysm (ICA) remains a devastating complication associated with a high degree of morbidity and mortality. In the past 2 decades, older people were often excluded from active treatment on the unique basis of their chronological age. Recent developments of less-invasive techniques for the diagnosis and treatment of ruptured and unruptured ICAs suggest that this fatalistic attitude toward older patients should be reconsidered. Furthermore, taking into account the heterogeneity of the elderly population, the use of a comprehensive geriatric assessment approach, based on a multidisciplinary evaluation, appears particularly helpful in proposing the optimal treatment strategy for each older patient. This article reviews the geriatric features of epidemiological, physiopathological, as well as clinical and therapeutic aspects of ruptured and unruptured ICAs.