40 research outputs found
Fecal S100A12: Identifying Intestinal Distress in Very-Low-Birth-Weight Infants
ABSTRACT Objectives: The aim of the study was to determine whether longitudinal measurements of fecal S100A12, a damage-associated molecular pattern protein, which is released from neutrophils or monocytes under stress, can detect very-low-birth-weight (VLBW) infants at risk for intestinal distress apart from necrotizing enterocolitis. Methods: This prospective study included 46 VLBW infants with intestinal distress and 49 reference patients. Meconium and stool samples were collected prospectively on alternate days for 4 weeks, and fecal S100A12 was measured by enzyme-linked immunosorbent assay. Results: Gestational age and weight at birth were significantly lower in patients with intestinal distress when compared to unaffected reference infants. Median levels of fecal S100A12 were significantly higher in patients with intestinal distress at onset of disease and before compared with unaffected reference infants. Median levels of fecal S100A12 declined steadily to baseline levels within 2 weeks after disease onset. The ideal cutoff value for identifying patients with intestinal distress within 7 days before disease onset was 60 mg/kg (sensitivity 0.73; specificity 0.55). Conclusions: Fecal S100A12 levels are increased in VLBW infants with intestinal distress; however, the potential for S100A12 as an early biomarker is largely limited by overlaps between values of infants with intestinal distress and the reference population
Imaging individual solute atoms at crystalline imperfections in metals
Directly imaging all atoms constituting a material and, maybe more importantly, crystalline defects that dictate materials\u27 properties, remains a formidable challenge. Here, we propose a new approach to chemistry-sensitive field-ion microscopy (FIM) combining FIM with time-of-flight mass-spectrometry (tof-ms). Elemental identification and correlation to FIM images enabled by data mining of combined tof-ms delivers a truly analytical-FIM (A-FIM). Contrast variations due to different chemistries is also interpreted from density-functional theory (DFT). A-FIM has true atomic resolution and we demonstrate how the technique can reveal the presence of individual solute atoms at specific positions in the microstructure. The performance of this new technique is showcased in revealing individual Re atoms at crystalline defects formed in Ni–Re binary alloy during creep deformation. The atomistic details offered by A-FIM allowed us to directly compare our results with simulations, and to tackle a long-standing question of how Re extends lifetime of Ni-based superalloys in service at high-temperature
Expression of Human Beta-Defensins in Children with Chronic Inflammatory Bowel Disease
Background: Human beta-defensins (hBDs) are antimicrobial peptides known to play a major role in intestinal innate host defence. Altered mucosal expression of hBDs has been suggested to be implicated in chronic inflammatory bowel disease pathogenesis. However, little is known about expression of these peptides in children. Methods: Intestinal biopsies were obtained from the duodenum (n = 88), terminal ileum (n = 90) and ascending colon (n = 105) of children with Crohn’s disease (n = 26), ulcerative colitis (n = 11) and healthy controls (n = 16). Quantitative realtime (RT) PCR was performed and absolute mRNA copy numbers analyzed for hBD1-3 as well as inflammatory cytokines IL-8 and TNF-alpha. Results: Significant induction of hBD2 and hBD3 was observed in the inflamed terminal ileum and ascending colon of IBD children. In the ascending colon induction of hBD2 was found to be significantly lower in children with Crohn’s disease compared to ulcerative colitis. A strong correlation was found between inducible defensins hBD2 and 3 and the inflammatory cytokines IL-8 and TNF-alpha, both in the terminal ileum and ascending colon. Conclusion: Our study demonstrates distinct changes in hBD expression throughout the intestinal tract of children with IBD
Automated parametrization and validation of simplified models of the interatomic interaction
Materialeigenschaften ergeben sich aus einem komplexen Zusammenspiel der Chemie, atomaren Struktur und Mikrostruktur. Dies muss durch genaue und effiziente Modelle beschrieben werden, um mittels Computersimulationen neue Materialien zu entdecken und zu optimieren. Dafür eignen sich sorgfältig parametrisierte analytische Bond-Order Potentiale (BOPs). Es werden neue Hilfsmittel entwickelt, die den Parametrisierungsprozess vereinfachen. Das sind Tight-Binding (TB) Modelle über das Periodensystem, eine Karte lokaler atomarer Umgebungen und ein automatisiertes Parametrisierungsprotokoll zur Optimierung der Parameter analytischer BOPs. Die Optimierung wird durch die TB Modelle initialisiert und Referenzdaten werden durch die Karte lokaler atomarer Umgebungen ausgewählt. Exemplarisch wird ein analytisches BOP für das Element Rhenium parametrisiert. Das Parametrisierungsprotokoll kann routinemäßig angewendet werden und ermöglicht somit Untersuchungen komplexer atomarer Strukturen
Human astrovirus infection associated with encephalitis in an immunocompetent child: a case report
Background
Until today, classic human astroviruses have not been associated with central nervous system infections in immunocompetent patients.
Case presentation
A 16-month-old Caucasian girl presented with repetitive generalized seizures with a 4-day history of watery diarrhea, which had already gradually improved. Initially, the prolonged seizures ceased after systemic midazolam treatment and were thought to be fever associated. However, her mental status remained altered, and after seizure recurrence, she was transferred to our pediatric intensive care unit. Seizure control was achieved by a combination of high-dose levetiracetam and phenobarbital, but she remained unconscious. An electroencephalogram at this time revealed generalized high voltage theta activity. All laboratory analyses, including extended blood and cerebrospinal fluid analyses, and a brain magnetic resonance imaging were normal.
On day 4, the child gradually became conscious, but was very agitated and not able to walk. Since an electroencephalogram at this time still revealed generalized high voltage theta activity, although she had not received sedative medications for 72 hours, she was diagnosed as having encephalopathy. At that time, results of diagnostic testing of the stool sample were positive for classic astrovirus infection, and we decided to analyze the initially obtained cerebrospinal fluid for astrovirus as well. Cerebrospinal fluid was also found positive for human astrovirus. Sequencing analysis revealed a classic astrovirus genotype 1 with exactly the same nucleotide sequence as in the feces. Clinically, the child gradually improved and was discharged on day 9.
Conclusions
Whereas the new human astrovirus subtypes have been recently associated with central nervous system infection, this is the first case of encephalitis in an immunocompetent child due to classic human astrovirus. Considering that classic human astroviruses are the third most common etiological agents of viral gastroenteritis in children, we believe that human astroviruses as causative agents for central nervous system infections should be considered more often, especially in children and infants with preceding gastroenteritis.Peer Reviewe