MicroRNA-146a-mediated downregulation of IRAK1 protects mouse and human small intestine against ischemia/reperfusion injury

Intestinal ischemia/reperfusion (I/R) injury causes inflammation and tissue damage and is associated with high morbidity and mortality. Uncontrolled activation of the innate immune system through toll-like receptors (Tlr) plays a key role in I/R-mediated tissue damage but the underlying mechanisms have not been fully resolved. Here, we identify post-transcriptional upregulation of the essential Tlr signalling molecule interleukin 1 receptor-associated kinase (Irak) 1 as the causative mechanism for post-ischemic immune hyper-responsiveness of intestinal epithelial cells. Increased Irak1 protein levels enhanced epithelial ligand responsiveness, chemokine secretion, apoptosis and mucosal barrier disruption in an experimental intestinal I/R model using wild-type, Irak1^−/− and Tlr4^−/− mice and ischemic human intestinal tissue. Irak1 accumulation under hypoxic conditions was associated with reduced K48 ubiquitination and enhanced Senp1-mediated deSUMOylation of Irak1. Importantly, administration of microRNA (miR)-146a or induction of miR-146a by the phytochemical diindolylmethane controlled Irak1 upregulation and prevented immune hyper-responsiveness in mouse and human tissue. These findings indicate that Irak1 accumulation triggers I/R-induced epithelial immune hyper-responsiveness and suggest that the induction of miR-146a offers a promising strategy to prevent I/R tissue injury.

Anuria during pneumoperitoneum in infants and children: a prospective study

INTRODUCTION

Transient oliguria during laparoscopic surgery is a known phenomenon. Currently, no data on the impact of pneumoperitoneum on renal function in children are available.

PATIENTS AND METHODS

Thirty children with normal kidney function, who underwent laparoscopic surgery, were included in a prospective study. A transurethral catheter was placed to measure urine output during and 6 hours after operation. Renal blood flow (resistive index) was evaluated by Doppler ultrasound of a segmental renal artery before surgery, every 15 minutes during laparoscopy, and after 24 hours. Blood and urine samples were studied before and 24 hours after surgery. Hemodynamic parameters were monitored continuously during standardized anesthesia, including a standardized intravenous infusion regimen.

RESULTS

Urine output decreased within 45 minutes of pneumoperitoneum in all patients. Of 8 children younger than 1 year, 7 (88%) developed anuria vs 3 of 22 (14%) children aged 1 to 15 years (P < .001). Nine children 1 year and older (32%) developed oliguria. There was a significant recovering in the mean urine output until 5 to 6 hours after pneumoperitoneum in both age groups. No significant alterations of the renal blood flow (resistive index) and the serum and urine levels of cystatin C, creatinine, and urea nitrogen were evident until 24 hours postoperatively. The volume of infusion during pneumoperitoneum did not correlate with urine output.

CONCLUSION

Pneumoperitoneum leads to anuria in most children younger than 1 year and to oliguria in about one third of older children. This is a completely reversible phenomenon. Urine output should not be taken into consideration for calculating intravenous fluid administration during pneumoperitoneum in children.

Complications of the minimally invasive repair of pectus excavatum

BACKGROUND

Minimally invasive repair of pectus excavatum (MIRPE) has become widely popular since its introduction in the late 1990s by Nuss. We describe 1 unusual complication after MIRPE and 1 life-threatening bleeding during removal of the pectus bar.

METHODS

We report the cases of 2 patients in a single institution, more than 100 MIRPE procedures performed so far, and review of literature.

CASES

A 14-year-old girl presented 6 months after MIRPE in another institution. During removal of the pectus bar, a massive hemorrhage from both chest wounds occurred, requiring emergency sternotomy. Arrosion of a pulmonary vessel close to the metal bar had led to the bleeding. The second case was a bilateral sternoclavicular dislocation after MIRPE, which has not caused symptoms so far, in a 13-year-old girl.

CONCLUSIONS

Numerous operative and postoperative complications after MIRPE are feasible. This is the first report of a life-threatening bleeding during removal of the pectus bar. Minimally invasive repair of pectus excavatum procedure and removal of the pectus bar should only occur in specialized institutions with wide experience in thoracic surgery.

Gene expression profile of the infective murine model for biliary atresia

One hypothesis of the pathogenesis of biliary atresia (BA) is a virus-induced and immune-mediated injury to bile duct cells as mimicked in the rotavirus-induced murine model. This theory is supported by studies showing a predominant T helper cell response type 1-like phenotype of inflammation with increased interferon gamma-induced chemokines in the liver of humans and mice suffering from BA. Recent gene expression profiling studies using microarray analysis showed the induction of a proinflammatory state in human liver specimens with high analogies in extrahepatic biliary tissue of BA mice. The aim of the present study was a microarray analysis of gene expression in the liver of Balb/c mice, comparing infected mice that show the phenotype of BA versus infected mice without symptoms, thus trying to elucidate genes that are not related to the viral origin of this model, but to the specific pathogenesis of the clinical picture of BA. Fifteen mug of RNA, each of three BA-positive and three BA-negative mice, were pooled and comparatively hybridized to spotted cDNA microarrays containing 250 key genes with high relevance to immunological settings. We identified the 40 genes most differentially expressed in mice with and without BA. The majority of genes with higher expression in BA-positive mice encoded proinflammatory cytokines involved in the Th1 pathway, such as CCL2, CCL5, CCR5, CXCL10, CCL2, IL1F5 and in apoptosis, such as DDR3 and granzyme A and B. In this initial study of the molecular characterization of our RRV-induced BA mouse model system, we also found potential novel candidates important to BA etiology, such as growth hormone receptor and insulin-like growth factor. Of particular interest, very low expression of TIMD2 was observed in BA-positive mice. TIMD2 plays a critical role in the regulation of a Th2-type response through the inhibition of IFN gamma.

Laparoscopic nephroureterectomy in children: a prospective study on Ligasure versus Clip/Ligation

PURPOSE

The present study was performed to compare dissection of the renal hilar vessels in laparoscopic transabdominal nephrectomy in children using the Endo-Ligasure vessel sealing system versus clip/ligation.

PATIENTS AND METHODS

In a prospective and comparative study carried out from February 2003 to April 2004, 10 consecutive patients (group 1) underwent laparoscopic transabdominal nephroureterectomy using clips or intracorporeally performed ligations, respectively. From April 2004 to April 2005, 10 consecutive patients (group 2) underwent the same procedure using the Endo-Ligasure vessel sealing system. Indications for surgery were confirmed non-functioning kidneys secondary to benign unilateral renal disease and no prior surgery. The age and underlying disease distribution and the affected side were not significantly different between the two groups.

RESULTS

The operating time was significantly lower in the Endo-Ligasure group (group 1: median 167 vs. group 2: 108 min, p < 0.05). Bleeding of the renal artery occurred due to dislocation of a suture ligation, which was treated laparoscopically with an intracorporeal suture ligation. Blood loss was negligible in all patients. All procedures were completed laparoscopically and recovery was uneventful.

CONCLUSIONS

Endo-Ligasure is a beneficial tool in laparoscopic transabdominal nephrectomy. It is safe, effective, and reduces operating times compared to clip application and intracorporeal suturing.

LigaSure in Laparoscopic Transperitoneal Heminephroureterectomy in Children: A Comparative Study

BACKGROUND

This study was conducted to evaluate the feasibility of using the LigaSure vessel sealing system (Valleylab, Boulder, CO) in laparoscopic transperitoneal vs. open retroperitoneal heminephroureterectomy in children.

MATERIALS AND METHODS

Seven consecutive patients with impaired renal duplex systems underwent laparoscopic heminephroureterectomies using LigaSure between April 2003 and April 2005. The operative time, complications, and hospital stay were analyzed prospectively. The data of 7 consecutive patients who had undergone open retroperitoneal heminephroureterectomy from 2001 to 2003 were analyzed for comparison purposes. The mean ages, underlying disease, and location of the affected kidney pole were not significantly different between these groups.

RESULTS

There were no intraoperative complications during laparoscopic heminephroureterectomy and all procedures were completed laparoscopically. The mean operative time of 144 minutes (range, 90-210 minutes) for laparoscopic heminephroureterectomy was somewhat longer than in open heminephroureterectomy-mean time 110 minutes (range, 60-165 minutes) (P = 0.5). Complications of open retroperitoneal heminephroureterectomy included bleeding of the surface of the remaining kidney pole in one patient, requiring extensive hemostatic suturing. Postoperative recovery was uneventful in all laparoscopic procedures, whereas intermittent retention of urine was noticed in one patient undergoing the open procedure.

CONCLUSION

Laparoscopic heminephroureterectomy using LigaSure is feasible in children and has a similar operative time compared to conventional heminephroureterectomy.

Exposure to carbon dioxide and helium reduces in vitro proliferation of pediatric tumor cells

BACKGROUND

Minimally invasive techniques are increasingly applied to children with malignant tumors. We showed previously that CO(2) used for pneumoperitoneum modulates the function of macrophages and polymorphonuclear cells via direct effects and via acidification. Numerous in vitro and small animal model studies also confirmed an alteration of the behavior of several types of adult tumor cells by CO(2). The impact of CO(2) and other gases used for pneumoperitoneum on the behavior of various pediatric tumors has not yet been determined.

METHODS

Cell lines of neuroblastoma (IMR 32, SK-N-SH, Sy5y), lymphoma (Daudi), hepatoblastoma (Huh 6), hepatocellular carcinoma (Hep G2), and rhabdomyosarcoma (Te 671) were incubated for 2 h. Incubation was performed with 100% CO(2), 100% helium, and 5% CO(2) as control. Cell proliferation was determined by the MTT-assay [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] by actively growing cells to produce a blue formazan product. The MTT-assay was performed before, directly after incubation, and daily for 4 days. Vitality of the cells was determined by trypan blue. The extracellular pH during incubation was measured during gas exposition every 10 min using Bayer Rapid Lab 855.

RESULTS

CO(2) for 2 h significantly decreased the proliferation of neuroblastoma, lymphoma, hepatoblastoma, and hepatocellular carcinoma cells. This decrease persisted over 4 days in neuroblastoma, lymphoma, and hepatocellular carcinoma cells. The CO(2) had no impact on hepatoblastoma and rhabdomyosarcoma cells. Helium had a similar effect on neuroblastoma cells. After 4 days, a significant decrease of cell activity was found in two neuroblastoma cell lines and in hepatoblastoma cells. Helium had no effect on lymphoma and hepatocellular carcinoma cells. The extracellular pH was 6.2 during incubation with CO(2), and 7.6 during incubation with helium.

CONCLUSION

CO(2) and helium may affect the proliferation of some pediatric tumor cell lines in vitro. However, some of these effects and the impact on the extracellular pH are differential. The role of pH modulation, hypoxia and direct effects of gases remain to be investigated before a general recommendation on the use of minimally invasive techniques in pediatric oncology can be given.

Trace metal release after minimally-invasive repair of pectus excavatum

Background

Several studies have shown a high incidence of metal allergy after minimally-invasive repair of pectus excavatum (MIRPE). We postulated that MIRPE is associated with a significant release of trace metal ions, possibly causing the allergic symptoms.

Methods

We evaluated the concentration with chromium, cobalt and nickel in blood, urine and tissue in patients prior to MIRPE and in patients who underwent an explantation of the stainless-steel bar(s) after three years.

Results

Our study group consisted of 20 patients (mean age 19 years) who had bar explantation and our control group included 20 patients (mean age 16 years) prior to MIRPE. At the time of bar removal we detected significantly elevated concentrations of chromium and nickel in the tissue compared to patients prior to the procedure (p<0,001). We also found a significant increase in the levels of chromium in urine and nickel in blood in patients three years post MIRPE (p<0,001). Four patients temporarily developed symptoms of metal allergy, all had elevated metal values in blood and urine at explantation.

Conclusions

Minimally-invasive repair of pectus excavatum can lead to a significant trace metal exposure.

Large noncollinearity and spin reorientation in the novel Mn2RhSn Heusler magnet

Noncollinear magnets provide essential ingredients for the next generation memory technology. It is a new prospect for the Heusler materials, already well known due to the diverse range of other fundamental characteristics. Here, we present a combined experimental and theoretical study of novel noncollinear tetragonal Mn(2)RhSn Heusler material exhibiting unusually strong canting of its magnetic sublattices. It undergoes a spin-reorientation transition, induced by a temperature change and suppressed by an external magnetic field. Because of the presence of Dzyaloshinskii-Moriya exchange and magnetic anisotropy, Mn(2)RhSn is suggested to be a promising candidate for realizing the Skyrmion state in the Heusler family.

Structural study and serological characterisation of the O-specific polysaccharide of Hafnia alvei PCM 1185, another Hafnia O-antigen that contains 3,6-dideoxy-3-[(R)-3-hydroxybutyramido]-D-glucose

The O-specific polysaccharide of H. alvei strain PCM 1185 contains D-glucose, D-glucuronic acid, 2-acetamido-2-deoxy-D-glucose, and 3,6-dideoxy-3-[(R)-3-hydroxybutyramido]-D-glucose (Qui3NAcyl) in the ratios 2:1:1:1 as well as O-acetyl groups. On the basis of sugar and methylation analyses of the polysaccharide before and after chemical modifications (O-deacetylation, carboxyl reduction, Smith degradation), as well as 1H and 13C NMR spectroscopy, including 1D sequential, selective spin-decoupling, 2D homonuclear and 13C,1H heteronuclear correlation spectroscopy (COSY), and 2D rotating-frame NOE spectroscopy, it was found that the polysaccharide has a pentasaccharide repeating unit with the following structure: [formula: see text] with O-acetyl groups present in nonstoichiometric amounts, mainly at position 2 of GlcA and position 6 of GlcNAc or lateral Glc. Serological study showed that H. alvei strain PCM 1185 can be placed in a new serotype D and that an O-acetyl group can be a part of its epitope.

Structure of the lipopolysaccharide core region of Hafnia alvei strains 1185 and 1204

Sugar and methylation analyses using gas chromatography/mass spectrometry and NMR spectroscopy proved that the core oligosaccharides of Hafnia alvei strains 1185 and 1204 have the following formula: carbohydrate sequence [see text] where Kdo = 3-deoxy-oct-2-ulosonic acid and P-PEtN = diphosphorylethanolamine. The structure shown above is a slight modification of the typical core region of H. alvei lipopolysaccharides. The difference refers to one sugar only: terminal galactose is present in the core of strains of 1185 and 1204, while terminal glucose in the typical core.

Single-lung ventilation with carbon dioxide hemipneumothorax: hemodynamic and respiratory effects in piglets

OBJECTIVES

Video-assisted thoracoscopic surgery (VATS) has become a standard procedure in pediatric surgery. To facilitate surgical access, the dependent lung has to collapse using intrathoracic carbon dioxide insufflation and/or single-lung ventilation. These procedures can induce hemodynamic deteriorations in adults. The potential impacts of single-lung ventilation in combination with capnothorax on hemodynamics in infants have never been studied before.

AIM

We conducted a randomized experimental study focusing on hemodynamic and respiratory changes during single-lung ventilation with or without capnothorax in a pediatric animal model.

METHODS

Twelve piglets were randomly assigned to receive single-lung ventilation with (SLV-CO(2) ) or without (SLV) capnothorax with an insufflation pressure of 5 mmHg for a period of two hours. Before, during, and after single-lung ventilation, hemodynamic and respiratory parameters were measured.

RESULTS

Although mean arterial pressure remained stable during the course of the study and no critical incidents were monitored, cardiac index (CI) decreased significantly with SLV-CO(2) (baseline 3.6 ± 1.6 l · min(-1) · m(-2) vs 2.9 ± 1.1 l · min(-1) · m(-2) at 120 min, P < 0.05). Furthermore, global end-diastolic volume and intrathoracic blood volume (ITBV) decreased as well significantly with SLV-CO(2) , causing a significant between-group difference in ITBV (P < 0.05).

CONCLUSIONS

Despite a decrease in CI and preload parameters, the combination of single-lung ventilation and low-pressure capnothorax was well tolerated in piglets and could justify further clinical studies to be performed in infants and children focusing on hemodynamic and respiratory changes during VATS.

Immunochemical characterization of lipopolysaccharide from glucose-nonfermenting gram-negative clinical bacterial isolate

A glucose-nonfermenting Gram-negative bacterial strain isolated from bronchofiberoscope used for examination of the patients suffering from pulmonary diseases was subjected to phenol-water extraction. Lipopolysaccharides (LPS) isolated from the water and the phenol phase differed in fatty acid composition. Both contained xylose, glucose, glucosamine and components typical for LPS, namely heptose, 3-deoxyoctulosonic acid (Kdo) and 3-hydroxymyristic acid. The presence of sphingosine in all LPS preparations classifies the strain to the genus Sphingomonas.

Experimentally Induced Biliary Atresia by Means of Rotavirus-Infection Is Directly Linked to Severe Damage of the Microvasculature in the Extrahepatic Bile Duct

Vascular damage has been reported to contribute to atresia formation in several diseases including biliary atresia. This study focused on the extrahepatic biliary plexus in experimental biliary atresia. Newborn BALB/cAnNCrl-pups were infected with rhesus rotavirus within 24 hr after birth to induce experimental biliary atresia. The extrahepatic biliary plexus was examined by confocal microscopy on whole-mount preparations, scored by three independent researchers, and further evaluated at the subcellular level with transmission electron microscopy. Imaging results revealed a progressive destruction of the extrahepatic biliary vascular plexus in the course of experimental biliary atresia induced by rotavirus infection. Endothelial cell damage was already visible as cell swelling and necrosis in the first days after infection and a damaged microcirculation that rapidly deteriorated with progression of obliterative cholangiopathy, was observed in the infected mice as early as 72 hr after birth. In experimental biliary atresia, the destruction of the extrahepatic biliary vascular plexus starts already in the first days postinfection and clearly precedes the morphological symptoms of atresia. The deterioration of the vascular bed architecture continues with disease progression. Therefore, we conclude that the (ultra)structural changes in the extrahepatic biliary microvasculature occurring before the visible onset of atresia has a predictive diagnostic value and this impairment in blood supply to the extrahepatic bile duct may be an important contributing factor to the pathogenesis of acquired biliary atresia. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. Anat Rec, 302:818-824, 2019. © 2018 Wiley Periodicals, Inc.