Outcomes in pediatric patients with documented delays between ileocolic intussusception diagnosis and therapeutic enema attempt: evaluation of reduction efficacy and complication rate.

BACKGROUND: Ileocolic intussusception is considered a pediatric emergency, with concerns for risk of significant morbidity in children with a prolonged intussusception state. Emergent therapy is standard of care, as prior studies have shown poor outcomes in patients with long delays (> 24 h) before intervention. Various factors can result in shorter delays, and there are limited studies evaluating outcomes in these patients. This study aimed to determine if there were differences in reduction success rates associated with short in-hospital time delays. OBJECTIVE: This study is to determine enema success rate and morbidity in patients with documented time delays between intussusception diagnosis and therapeutic enema. MATERIALS AND METHODS: A retrospective evaluation of pediatric patients with intussusception at a single children's hospital between 2007 and 2019 was performed. Patient's records were reviewed for time of symptom onset, radiologic diagnosis, and attempted enema. Ultrasounds and radiographs were reviewed for bowel obstruction, free peritoneal fluid, trapped fluid around the intussusceptum, and absent bowel wall perfusion. Patients were evaluated for efficacy of reduction attempt, requirement for surgical reduction, and complications including bowel resection and bowel perforation. RESULTS: There were 175 cases of ileocolic intussusception requiring enema reduction. Successful reduction occurred in 72.2% (13/18) of cases performed within 1 h of diagnosis; 74.3% (78/105) between 1 and3 h; 73.2% (30/41) between 3 and 6 h; and 81.2% (9/11) with greater than 6 h. Need for bowel resection was not associated with short delays between diagnosis and reduction attempts (p = .07). CONCLUSIONS: There was no difference in intussusception reduction efficacy or complication rate in patients with increasing time between imaging diagnosis of ileocolic intussusception and reduction attempt, including delay intervals up to 8 h.

Reevaluation of Poly(ethylene-alt-propylene)-block-Polydimethylsiloxane Phase Behavior Uncovers Topological Close-Packing and Epitaxial Quasicrystal Growth.

Reanalysis of an asymmetric poly(ethylene-alt-propylene)-block-polydimethylsiloxane (PEP-PDMS) diblock copolymer first investigated in 1999 has revealed a rich phase behavior including a dodecagonal quasicrystal (DDQC), a Frank-Kasper σ phase, and a body-centered cubic (BCC) packing at high temperature adjacent to the disordered state. On subjecting the sample to large amplitude oscillatory shear well below the σ-BCC order-order transition temperature (TOOT), small-angle X-ray scattering evidenced the emergence of a twinned BCC phase that, on heating, underwent a phase transition to an unusually anisotropic DDQC state. Surprisingly, we observe no evidence of this apparent epitaxy on heating or cooling through the equilibrium σ-BCC transition. We rationalize these results in terms of a shear-induced order-order transition and an apparent BCC-DDQC epitaxy favored by micelle translation-mediated ordering dynamics far below TOOT.

Formation of a C15 Laves Phase with a Giant Unit Cell in Salt-Doped A/B/AB Ternary Polymer Blends.

Salt-doped A/B/AB ternary polymer blends, wherein an AB copolymer acts as a surfactant to stabilize otherwise incompatible A and B homopolymers, display a wide range of nanostructured morphologies with significant tunability. Among these structures, a bicontinuous microemulsion (BµE) has been a notable target. Here, we report the surprising appearance of a robust C15 Laves phase, at compositions near where the BµE has recently been reported, in lithium bis(trifluoromethane) sulfonimide (LiTFSI)-doped low-molar-mass poly(ethylene oxide) (PEO)/polystyrene (PS)/symmetric PS-b-PEO block copolymer blends. The materials were analyzed by a combination of small-angle X-ray scattering (SAXS), 1H NMR spectroscopy, and impedance spectroscopy. The C15 phase emerges at a high total homopolymer volume fraction ϕH = 0.8 with a salt composition r = 0.06 (Li+/[EO]) and persists as a coexisting phase across a large area of the isothermal phase diagram with high PS homopolymer compositions. Notably, the structure exhibits a huge unit cell size, a = 121 nm, with an unusually high micelle core volume fraction (fcore = 0.41) and an unusually low fraction of amphiphile (20%). This unit cell dimension is at least 50% larger than any previously reported C15 phase in soft matter, despite the low molar masses used, unlocking the possibility of copolymer-based photonic crystals without compromising processability. The nanostructured phase evolution from lamellar to hexagonal to C15 along the EO60 isopleth (ϕPEO,homo-LiTFSI/ϕH = 0.6) is rationalized as a consequence of asymmetry in the homopolymer solubility limit for each block, which leads to exclusion of PS homopolymer from the PS-b-PEO brush prior to exclusion of the PEO homopolymer, driving increased interfacial curvature and favoring the emergence of the C15 Laves phase.

A15, σ, and a Quasicrystal: Access to Complex Particle Packings via Bidisperse Diblock Copolymer Blends.

A renewed focus on the phase behavior of nominally single-component, compositionally asymmetric diblock copolymers has revealed a host of previously unanticipated Frank-Kasper (FK) and quasicrystalline phases. However, these periodic and aperiodic particle packings have thus far only been reported in low molecular weight, highly conformationally asymmetric diblock copolymers, leaving researchers with a relatively small library of polymers in which these phases can be studied. In this work, we report on a simple approach to access these morphologies: blending two diblock copolymers with the same corona block length and varied core block lengths. Compositionally symmetric and asymmetric polystyrene-b-1,4-polybutadiene (SB) diblock copolymers with constant corona block lengths were blended together and shown via small-angle X-ray scattering and transmission electron microscopy to order into the FK A15 and σ phases, as well as a dodecagonal quasicrystal, providing a route to various particle packings in high molecular weight diblock copolymer melts.

Emergence of a C15 Laves Phase in Diblock Polymer/Homopolymer Blends.

The observation of complex, Frank-Kasper (FK) particle packings in diblock polymer melts has until recently been limited to low molecular weight, conformationally asymmetric polymers. We report temperature-dependent small-angle X-ray scattering (SAXS) studies of blends of a sphere-forming poly(styrene-block-1,4-butadiene) (SB) diblock polymer (Mn = 33.3 kg/mol, D = Mw/Mn = 1.08, fB = 0.18) with two different poly(1,4-butadiene) (B) homopolymer additives. When the B additive Mn is the same as that of the diblock core-forming B segment, these blends remarkably form tetrahedrally close-packed FK σ and Laves C14 and C15 phases with increasing B content. However, binary blends in which the B additive Mn is 60% of that of the diblock B segment form only the canonical body-centered cubic (BCC) particle packing and hexagonally-packed cylinders (HEXc). The observed phase behavior is rationalized in terms of "wet" and "dry" brush blending, whereby higher B Mn drives stronger localization of the homopolymer in the particle cores while preserving the interfacial area per SB diblock chain. The consequent packing constraints in these blends destabilize the BCC packing, and FK phases emerge as optimal minimal surface solutions to filling space at constant density while maximizing local particle sphericity.

Extended field of view magnetic resonance imaging for suspected osteomyelitis in very young children: is it useful?

BACKGROUND: Osteomyelitis is a challenging diagnosis for clinicians, particularly in very young children. At our institution, the magnetic resonance imaging (MRI) protocol in suspected osteomyelitis for children 5 years of age or younger includes a large field of imaging regardless of the clinical site of concern. OBJECTIVE: To determine if extended field of view (FOV) MRI contributes important information in young children with suspected osteomyelitis. MATERIALS AND METHODS: A retrospective study was performed including children 5 years of age or younger with suspected osteomyelitis from January 2011 to September 2015. All children underwent coronal fluid-sensitive MRI from neck to feet. Focused imaging was performed as necessary on abnormal sites depicted on survey imaging. Two radiologists reviewed the imaging findings, which were compared to the clinical outcome. RESULTS: We studied 51 children with a mean age of 2.2 years (range: 21 days-5.5 years); 53% were boys. Osteomyelitis was depicted by MRI in 20 subjects (39.2%). Survey coronal fluid-sensitive imaging was accomplished by adding a single fluid-sensitive series in 1 child, 2 series in 31 children, 3 series in 16 children and 4 series in 3 children. Survey imaging added a median total time of 6:51 min to the examination (range: 2.29-20.54 min). Extended FOV imaging added important information in 11/51 subjects (21.6%), in 6 cases (11.8%) of infection and in 5 cases (9.8%) by suggesting alternative diagnoses. CONCLUSION: The addition of extended FOV MRI in young children with suspected osteomyelitis added important clinical information in 21.6% of patients while only adding a median of 6:51 min to the examination. It is our experience that in children ≤5 years of age with suspected osteomyelitis, extended FOV imaging adds important information and may result in changes in management.

Role of Chain Length in the Formation of Frank-Kasper Phases in Diblock Copolymers.

The phase behavior of poly(styrene)-b-poly(1,4-butadiene) diblock copolymers with a polymer block invariant degree of polymerization N[over ¯]_{b}≈800 shows no evidence of Frank-Kasper phases, in contrast to low molar mass diblock copolymers (N[over ¯]_{b}<100) with the same conformational asymmetry. A universal self-concentration crossover parameter N[over ¯]_{x}≈400 is identified, directly related to the crossover to entanglement dynamics in polymer melts. Mean-field behavior is recovered when N[over ¯]_{b}>N[over ¯]_{x}, while complex low symmetry phase formation is attributed to fluctuations and space-filling constraints, which dominate when N[over ¯]_{b}

Cavernous Sinus Thrombosis in Children: Imaging Characteristics and Clinical Outcomes.

BACKGROUND AND PURPOSE: Cavernous sinus thrombosis (CST) is a rare life-threatening cerebrovascular disease known to cause carotid artery narrowing (CAN) and arterial ischemic stroke. The imaging features of CST and related complications have been reported in adults, but rarely in children. METHODS: We performed a retrospective review of children with imaging confirmed CST from 2003 to 2014, describing presenting symptoms, imaging findings, and treatment. RESULTS: Ten patients with CST were identified. All had CAN and 6 of 10 developed infarcts. Of 8 patients treated with anticoagulation therapy, 3 developed new infarcts. None required discontinuation of anticoagulation therapy because of bleeding. Visual impairment secondary to infectious neuritis was common. Imaging characteristics include cavernous sinus expansion, filling defects, restricted diffusion, arterial wall enhancement, empyema, superior ophthalmic vein enlargement and thrombosis, orbital cellulitis, and pituitary inflammation. CAN resolved in 60% of cases. Outcomes were mostly good, with a modified Rankin Scale score of ≤1 for 7 of 10 patients at discharge and 1 death. CONCLUSIONS: CAN and infarcts were common in this modest cohort of children with CST. Despite the high incidence of CAN and infarction, outcomes were often favorable. Although this is the largest cohort of childhood CST reported to date, large multicenter cohorts are needed to confirm our findings and determine the preferred therapeutic strategies for childhood CST.

Paracentesis-induced circulatory dysfunction: a primer for the interventional radiologist.

Paracentesis-induced circulatory dysfunction is a complication of large volume paracentesis that leads to faster reaccumulation of ascites, hyponatremia, renal impairment, and shorter survival. Knowledge of the pathophysiology, clinical presentation, diagnosis, and prevention of this condition is vital to the interventional radiologist as a valued team member in the treatment of ascites.

Pediatric posterior fossa ganglioglioma: unique MRI features and correlation with BRAF V600E mutation status.

Ganglioglioma (GG) is a rare pediatric brain tumor (1-4 %) with neoplastic glial and neuronal cells. Posterior fossa GGs (PF GGs) occur less frequently than supratentorial GGs (ST GGs). The BRAF V600E mutation has been reported in GGs and carries therapeutic implications. We compare the presenting symptoms, magnetic resonance imaging, BRAF V600E mutation status, treatment, and prognosis in children with ST and PF GGs. The neuro-oncology database at a tertiary care Children's Hospital was retrospectively reviewed from 1995 to 2010 for patients with ST and PF GG. All available imaging was reviewed. Symptoms, BRAF V600E mutation status, treatment, and survival data were collected from the electronic medical record and analyzed. Our series consisted of 11 PF GG and 20 ST GG. Children with PF GG presented with ataxia, cranial nerve deficits and long tract signs whereas the majority with ST GGs presented with seizures. On imaging, PF GGs were infiltrative and expansile solid masses with dorsal predominant "paintbrush" enhancement whereas ST GGs were well circumscribed mixed solid and cystic masses with heterogeneous enhancement. Five of 11 (45%) PF GGs and 6 of 9 (67%) ST GGs expressed the BRAF V600E mutation. No unique imaging features were identified in BRAF V600E mutation positive tumors. The majority of ST GGs were treated with surgery alone, whereas the majority of PF GGs required multimodality therapy. PF GGs had worse progression-free survival and a higher mortality rate compared with ST GGs. Unlike ST GGs, PF GGs are expansile, infiltrative, show dorsal predominant "paintbrush" enhancement, are not amenable to gross total resection, and have worse progression-free survival and mortality.

Lactate clearance time and concentration linked to morbidity and death in cardiac surgical patients.

BACKGROUND: Early predictors of morbidity after cardiac operations are lacking. Elevated lactate concentrations in the immediate postoperative period reflect unmet metabolic demand and may be associated with outcome. This study examined the association between early plasma lactate concentrations and outcome after cardiac operations. METHODS: As a retrospective cohort investigation, patient information was obtained from the Cardiovascular Information and the Anesthesiology Institute's patient registries. Inclusion criteria were all adult cardiac surgical patients undergoing isolated coronary artery bypass grafting or valve procedures, or coronary artery bypass grafting with a valve procedure, from January 1, 2008, to August 7, 2008 (arterial lactate values were added to the patient registry beginning January 1, 2008). RESULTS: Lactate concentrations during the initial 12 postoperative hours of a patient's stay in the cardiovascular intensive care unit were averaged (mean lactate concentration), and linear regression concentrations over time were used to predict when the lactate concentration would reach 1.5 mmol/L in individual patients (predicted lactate clearance time). We also considered the product of the mean and clearance (product value). Predicted lactate clearance time, mean lactate concentration, and product value were associated with any type of reoperation, death, and a set of composite outcomes (p < 0.001 for each). The accuracy of these indices was moderate to good, with the highest C statistic (for product value) being 0.82. CONCLUSIONS: Predicted lactate clearance time, mean lactate concentration, and product value are each associated with death, any type of reoperation, and a set of composite outcomes in patients undergoing coronary artery bypass grafting or valve operations, or both. Product value provided the best early prognostic guidance in individual patients.

Profound hyponatremia in cirrhosis: a case report.

INTRODUCTION: Cirrhosis of the liver commonly leads to a state of chronic hypervolemic hyponatremia. Profound exacerbation of the hyponatremic state may occur in patients with decompensated cirrhosis in conjunction with acute stressors such as infection or binge alcohol ingestion. CASE PRESENTATION: A 47 year old man with a history of alcoholic cirrhosis presented to the hospital with symptomatic profound hyponatremia (serum sodium concentration of 105 meq/L) due to a recent infection and binge drinking. The patient was treated with antibiotics, diuretics and hypertonic saline and was placed on a fluid restricted diet. The serum sodium level corrected slowly over four days with symptomatic improvement occurring after two days. A brief discussion of the symptoms and treatment of acute and chronic hyponatremia in the setting of cirrhosis is included. CONCLUSION: In patients with cirrhosis, it is important to recognize the symptoms of hyponatremia, identify and treat any exacerbating conditions early in their course, and correct the serum sodium concentration slowly with frequent monitoring.

Proteomics, bioinformatics and targeted gene expression analysis reveals up-regulation of cochlin and identifies other potential biomarkers in the mouse model for deafness in Usher syndrome type 1F.

Proteins and protein networks associated with cochlear pathogenesis in the Ames waltzer (av) mouse, a model for deafness in Usher syndrome 1F (USH1F), were identified. Cochlear protein from wild-type and av mice at postnatal day 30, a time point in which cochlear pathology is well established, was analyzed by quantitative 2D gel electrophoresis followed by mass spectrometry (MS). The analytic gel resolved 2270 spots; 69 spots showed significant changes in intensity in the av cochlea compared with the control. The cochlin protein was identified in 20 peptide spots, most of which were up-regulated, while a few were down-regulated. Analysis of MS sequence data showed that, in the av cochlea, a set of full-length isoforms of cochlin was up-regulated, while isoforms missing the N-terminal FCH/LCCL domain were down-regulated. Protein interaction network analysis of all differentially expressed proteins was performed with Metacore software. That analysis revealed a number of statistically significant candidate protein networks predicted to be altered in the affected cochlea. Quantitative PCR (qPCR) analysis of select candidates from the proteomic and bioinformatic investigations showed up-regulation of Coch mRNA and those of p53, Brn3a and Nrf2, transcription factors linked to stress response and survival. Increased mRNA of Brn3a and Nrf2 has previously been associated with increased expression of cochlin in human glaucomatous trabecular meshwork. Our report strongly suggests that increased level of cochlin is an important etiologic factor leading to the degeneration of cochlear neuroepithelia in the USH1F model.