Predictors of mortality for patients admitted to the intensive care unit with obstructing septic stones.

INTRODUCTION: Patients diagnosed with septic stone are at significant risk of morbidity and mortality should source control through drainage be delayed, and they are often admitted to intensive care units (ICU) for hemodynamic support. The purpose of this study was to determine patient factors that may predict mortality in patients admitted to ICU with septic stone, particularly whether rural patients at a greater distance from a tertiary care center were at greater risk of mortality given the inherent delay in intervention. METHODS: The Manitoba Intensive Care Unit prospective registry began in 1999 and includes all patients admitted to ICU across Manitoba. Baseline characteristics, such as age, gender, vital signs, creatinine, Charlson comorbidity index (CCI), mortality outcomes, and location of residency were obtained for those admitted to ICU for septic stone. Association between death and clinical/demographic variables was performed with adjusted multivariable logistical regression analysis. RESULTS: A total of 342 patients admitted to the ICU were analyzed, with a mean age of 63.5±15.5 years. Baseline characteristics were similar between groups (p>0.05). On multivariable adjusted logistical regression, the presence of acute kidney injury (AKI) (p<0.001) and intubation (p<0.001) were associated with mortality. There was no difference in mortality attributable to location of residency, vital signs, or CCI. CONCLUSIONS: Among patients admitted to the ICU for septic stones in Manitoba, we demonstrate an association between AKI and intubation with mortality. Other factors, such as whether patients were from a rural region and baseline patient characteristics, were not predictive of mortality.

Laparoscopic ligation of ectopic ureter in pediatric patients: a safe surgical option for the management of urinary incontinence due to ectopic ureters.

BACKGROUND: Ureteric ectopia is a pediatric urinary incontinence cause in girls. It is traditionally managed through hemi-nephrectomy or uretero-ureterostomy, which have the potential for complications including anastomotic stricture, leak, bleeding, and de-vascularization of the functioning renal moiety. Laparoscopic ureteric clipping has been shown to be a good alternative but has not been widely adopted yet. We provide our experience with this technique. METHODS: We retrospectively reviewed the data of 6 patients who underwent laparoscopic clipping of ectopic ureter between 2014 and 2019. We collected the following information: clinical presentation, preoperative and postoperative imaging, age at presentation, age at surgery, operative time, complications, length of stay, length of follow-up, as well as continence outcomes. RESULTS: Five patients were diagnosed with a duplex system associated with an ectopic upper pole ureter. One patient was noted to have a non-functional kidney associated with an ectopic ureter. Median age at presentation was 5 years (6 weeks-9 years), while at surgery was 8 years (2-13 years). Four patients were referred for incontinence, 1 was referred for antenatal hydronephrosis, 1 presented with urosepsis. The preoperative renal pelvis anteroposterior diameter (APD) was 8.60 cm (median) (6.80-8.70 cm). At the post-operative follow-up, the APD increased to median 9.1 cm (6.80-11.50 cm). Median operative time was 91 min (42-60 min). Complications were seen in only one patient who developed an immediate postoperative urinary tract infection (UTI). Five patients were discharged home the same day of the surgery, while the patient who developed UTI went home on post-operative day 3. Median follow-up was 33 months (22-72 months). Currently, all patients have achieved daytime urinary continence. No patient had UTI during the follow-up period. CONCLUSION: Laparoscopic ureteric clipping of the ectopic ureter appears to be a valid alternative to extirpative or reconstructive procedures. Follow-up shows an increase in hydronephrosis without any consequence for the patients. Further studies are necessary to reinforce these observations.

Mass spectrometry for protein sialoglycosylation.

Sialic acids are a family of structurally unique and negatively charged nine-carbon sugars, normally found at the terminal positions of glycan chains on glycoproteins and glycolipids. The glycosylation of proteins is a universal post-translational modification in eukaryotic species and regulates essential biological functions, in which the most common sialic acid is N-acetyl-neuraminic acid (2-keto-5-acetamido-3,5-dideoxy-D-glycero-D-galactononulopyranos-1-onic acid) (Neu5NAc). Because of the properties of sialic acids under general mass spectrometry (MS) conditions, such as instability, ionization discrimination, and mixed adducts, the use of MS in the analysis of protein sialoglycosylation is still challenging. The present review is focused on the application of MS related methodologies to the study of both N- and O-linked sialoglycans. We reviewed MS-based strategies for characterizing sialylation by analyzing intact glycoproteins, proteolytic digested glycopeptides, and released glycans. The review concludes with future perspectives in the field.

Characterization of the dTDP-Fuc3N and dTDP-Qui3N biosynthetic pathways in Campylobacter jejuni 81116.

The Gram-negative bacterium Campylobacter jejuni 81116 (Penner serotype HS:6) has a class E lipooligosaccharide (LOS) biosynthesis locus containing 19 genes, which encode for 11 putative glycosyltransferases, 1 lipid A acyltransferase and 7 enzymes thought to be involved in the biosynthesis of dideoxyhexosamine (ddHexN) moieties. Although the LOS outer core structure of C. jejuni 81116 is still unknown, recent mass spectrometry analyses suggest that it contains acetylated forms of two ddHexN residues. For this investigation, five of the genes encoding enzymes reportedly involved in the biosyntheses of these sugar residues were examined, rmlA, rmlB, wlaRA, wlaRB and wlaRG. Specifically, these genes were cloned and expressed in Escherichia coli, and the corresponding enzymes were purified and tested for biochemical activity. Here we present data demonstrating that RmlA functions as a glucose-1-phosphate thymidylyltransferase and that RmlB is a thymidine diphosphate (dTDP)-glucose 4,6-dehydratase. We also show, through nuclear magnetic resonance spectroscopy and mass spectrometry analyses, that WlaRG, when utilized in coupled assays with either WlaRA or WlaRB and dTDP-4-keto-6-deoxyglucose, results in the production of either dTDP-3-amino-3,6-dideoxy-d-galactose (dTDP-Fuc3N) or dTDP-3-amino-3,6-dideoxy-d-glucose (dTDP-Qui3N), respectively. In addition, the X-ray crystallographic structures of the 3,4-ketoisomerases, WlaRA and WlaRB, were determined to 2.14 and 2.0 Å resolutions, respectively. Taken together, the data reported herein demonstrate that C. jejuni 81116 utilizes five enzymes to synthesize dTDP-Fuc3N or dTDP-Qui3N and that WlaRG, an aminotransferase, can function on sugars with differing stereochemistry about their C-4' carbons. Importantly, the data reveal that C. jejuni 81116 has the ability to synthesize two isomeric ddHexN forms.

Hypoxia-increased expression of genes involved in inflammation, dedifferentiation, pro-fibrosis, and extracellular matrix remodeling of human bladder smooth muscle cells.

Partial bladder outlet obstruction (pBOO) is characterized by exaggerated stretch, hydrodynamic pressure, and inflammation which cause significant damage and fibrosis to the bladder wall. Several studies have implicated hypoxia in its pathophysiology. However, the isolated progressive effects of hypoxia on bladder cells are not yet defined. Sub-confluent normal human bladder smooth muscle cells (hbSMC) were cultured in 3% O2 tension for 2, 24, 48, and 72 h. RNA, cellular proteins, and secreted proteins were used for gene expression analysis, immunoblotting, and ELISA, respectively. Transcription of hypoxia-inducible factor (HIF)1α and HIF2α were transiently induced after 2 h of hypoxia (p < 0.05), whereas HIF3 was upregulated after 72 h (p < 0.005). HIF1 and HIF3α proteins were significantly induced after 2 and 72 h, respectively. VEGF mRNA increased significantly after 24 and 72 h (p < 0.005). The inflammatory cytokines, TGFB (protein and mRNA), IL 1ß, 1L6, and TNFα (mRNA) demonstrated a time-dependent increased expression. Furthermore, the anti-inflammatory cytokine IL-10 was downregulated after 72 h (p < 0.05). Evidence of smooth muscle cell dedifferentiation included increased αSMA, vimentin, and desmin. Evidence of pro-fibrotic changes included increased CTGF, SMAD 2, and SMAD 3 as well as collagens 1, 2, 3, and 4, fibronectin, aggrecan, and TIMP 1 transcripts (p < 0.05). Total collagen proteins also increased time-dependently (p < 0.05). Together, these results show that exposure of hbSMC to low oxygen tension results in intense hypoxic cascade, including inflammation, de-differentiation, pro-fibrotic changes, and increased extracellular matrix expression. This elucidates mechanisms of hypoxia-driven bladder deterioration in bladder cells, which is important in tailoring in vivo experiments and may ultimately translate into improved clinical outcomes.

Host resistance to intranasal Acinetobacter baumannii reinfection in mice.

Acinetobacter baumannii is a major causative agent of healthcare-associated infection and develops multidrug resistance rapidly. However, little is known in the host defense mechanisms against this infection. In this study, we examined if mice recovered from a previous intranasal A. baumannii infection (recovered mice) are fully protected against a subsequent reinfection. We found that, despite the presence of specific serum IgG and mucosal IgA responses prior to the reinfection, the recovered mice were only marginally better protected against intranasal challenge with low doses of homologous or heterologous A. baumannii strains than the naïve mice. Post-challenge immune and inflammatory (cells and cytokines) responses were generally comparable between recovered and naïve mice although the recovered mice produced significantly higher amounts of IFN-γ and IL-17 and had higher percentages and numbers of resident lung CD44(hi)CD62L(-)CD4(+) and CD19(+) B lymphocytes. Taken together, our results suggest that mice recovered from a previous A. baumannii infection remain susceptible to reinfection, indicating the complexity of immune protection mechanism for this Gram-negative, multidrug-resistant emerging pathogen.