Lack of gamma delta T cells ameliorates inflammatory response after acute intestinal ischemia reperfusion in mice.

T-cells have been demonstrated to modulate ischemia-reperfusion injury (IRI) in the kidney, lung, liver, and intestine. Whereas most T-cell subpopulations contribute primarily to the antigen-specific effector and memory phases of immunity, γδ-T-cells combine adaptive features with rapid, innate-like responses that can place them in the initiation phase of immune reactions. Therefore, we aimed to clarify the role of γδ-T-cells in intestinal IRI. Adult wild-type (WT) and γδ-T-cell-deficient mice were subjected to acute intestinal IRI. Gene expression of pro-inflammatory cytokines and influx of leukocyte subpopulations in the gut were assessed by qPCR and flow cytometry. Serum transaminases were measured as an indicator of distant organ IRI. Intestinal IRI led to increased influx of neutrophils, pro-inflammatory cytokine expression and LDH/ALT/AST elevation. Selective deficiency of γδ-T-cells significantly decreased pro-inflammatory cytokine levels and neutrophil infiltration in the gut following IRI compared to controls. Furthermore, γδ-T-cell deficiency resulted in decreased LDH and transaminases levels in sera, indicating amelioration of distant organ injury. Increasing evidence demonstrates a key role of T-cell subpopulations in IRI. We demonstrate that γδ-T-cell deficiency ameliorated pro-inflammatory cytokine production, neutrophil recruitment and distant organ injury. Thus, γδ-T-cells may be considered as mediators contributing to the inflammatory response in the acute phase of intestinal IRI.

Systemic and regional cerebral perfusion in small infants undergoing minor lower abdominal surgery under awake caudal anaesthesia: An observational study.

BACKGROUND: Infants undergoing general anaesthesia have an increased risk of severe respiratory and cardiovascular critical events. Awake caudal anaesthesia is an alternative for small infants undergoing minor lower abdominal surgery. While clinical experience has shown stable intra-operative haemodynamic conditions, there are no studies evaluating systemic and regional cerebral perfusion during such a procedure. OBJECTIVES: The purpose of this study was to evaluate the effects of awake caudal anaesthesia on systemic and regional cerebral perfusion in small infants. DESIGN: A prospective observational cohort study. SETTING: Clinic of Anaesthesiology, University Children's Hospital, between November 2017 and June 2018. PATIENTS: Twenty small infants (postmenstrual age 36 to 54 weeks, weight 1800 to 5700 g) scheduled for lower abdominal surgery under awake caudal anaesthesia were enrolled in this study. INTERVENTION: Standard monitoring was expanded to include cardiac index using electrical velocimetry and regional cerebral oxygen saturation using near infrared spectroscopy. The caudal block was performed with 0.3% ropivacaine 1 ml kg Hypotension was defined as mean arterial blood pressure (BP) less than 35 mmHg and regional cerebral desaturation as regional cerebral oxygen saturation less than 80% of baseline. MAIN OUTCOMES: Mean arterial BP, cardiac index and regional cerebral oxygen saturation parameters under awake caudal anaesthesia. RESULTS: Mean arterial BP, cardiac index and regional cerebral oxygen saturation remained above the predefined lower limits. No episodes of hypotension or regional cerebral desaturation were observed. Operation time was 35 ±â€Š13 (range 20 to 71) min. The infants were discharged to the neonatal ward after the end of surgery, and milk was fed 22 ±â€Š15 (range 6 to 55) min thereafter. Five preterm infants experienced self-limiting episodes of apnoea intra-operatively. CONCLUSION: The current study shows that awake caudal anaesthesia does not impair systemic and regional cerebral perfusion in small infants. TRIAL REGISTRATION: German registry of clinical studies (DRKS-ID: 800015742).

Conventional alpha beta (αß) T cells do not contribute to acute intestinal ischemia-reperfusion injury in mice.

PURPOSE: Ischemia-reperfusion injury (IRI) is associated with significant patient mortality and morbidity. The complex cascade of IRI is incompletely understood, but inflammation is known to be a key mediator. In addition to the predominant innate immune responses, previous research has also indicated that αß T cells contribute to IRI in various organ models. The aim of this study was to clarify the role αß T cells play in IRI to the gut. METHODS: Adult wild-type (WT) and αß T cell-deficient mice were subjected to acute intestinal IRI with 30min ischemia followed by 4h reperfusion. The gene expression of pro-inflammatory cytokines was measured by qPCR, and the influx of leukocyte subpopulations in the gut was assessed via flow cytometry and histology. Pro-inflammatory cytokines in the serum were measured, and transaminases were assessed as an indicator of distant organ IRI. RESULTS: Intestinal IRI led to an increased expression of pro-inflammatory cytokines in the gut tissue and an influx of leukocytes that predominantly consisted of neutrophils and macrophages. Furthermore, intestinal IRI increased serum IL-6, TNF-α, and ALT/AST levels. The αß T cell-deficient mice did not exhibit a more significant increase in pro-inflammatory cytokines in the gut or serum following IR than the WT mice. There was also no difference between WT- and αß T cell-deficient mice in terms of neutrophil infiltration or macrophage activation. Furthermore, the increase in transaminases was equal in both groups indicating that the level of distant organ injury was comparable. CONCLUSION: An increasing body of evidence demonstrates that αß T cells play a key role in IRI. In the gut, however, αß T cells are not pivotal in the first hours following acute IRI as deficiency does not impact cytokine production, neutrophil recruitment, macrophage activation, or distant organ injury. Thus, αß T cells may be considered innocent bystanders during the acute phase of intestinal IRI.

Rotavirus particles in the extrahepatic bile duct in experimental biliary atresia.

BACKGROUND: Biliary atresia (BA) is the most common indication for liver transplantation in children. The experimental model of BA, induced by rotavirus infection in neonatal mice, has been widely used to investigate the inflammatory aspects of this disease. We investigated the kinetics and the localization of the viral infection in this murine model. METHODS: In this study 399 animals were employed for a detailed investigation of rhesus rotavirus (RRV)-induced BA. RRV kinetics was analyzed by rtPCR and its (sub) cellular localization investigated using whole mounts which were further processed for confocal and electron microscopy. RESULTS: The BA mouse model resulted in up to 100% induction of atresia following RRV injection. The kinetics of RRV infection differed between liver and extrahepatic bile ducts. While the virus peak up to day 10 postinfection was similar in both organs, the virus remained detectable in extrahepatic bile duct cells up to day 21. Interestingly, RRV particles were localized not only in cholangiocytes but also in cells of the subepithelial layers, potentially macrophages. CONCLUSIONS: RRV remains present in the extrahepatic bile duct cells after an initial virus peak. Viral particles were detected in subepithelial cells in contrast to the described tropism toward cholangiocytes.

Plasma volume replacement with HES 130/0.42 obviates negative side effects of pneumoperitoneum in piglets.

BACKGROUND: Evidence-based guidelines on optimal perioperative fluid management in infants have not been established. Recent randomized trials in major abdominal surgery in adults suggest that large volumes of fluid may increase morbidity and hospital stay. Our own clinical experience in infants undergoing laparoscopic surgery is different. So the aim of this study was to compare a crystalloid vs a plasma volume stabilizing fluid management regime during prolonged pneumoperitoneum (PP) in an experimental setting. METHODS: Fifteen German landrace piglets were randomized to one of the following treatment groups: control (no PP, 5 ml x kg(-1) x h(-1) electrolyte solution); crystalloid (180 min of PP, 5 ml x kg(-1) x h(-1) electrolyte solution); colloid (180 min of PP, single bolus of 5 ml x kg(-1) followed by 5 ml x kg(-1) x h(-1) hydroxyethyl starch 130/0.42/6:2). After decompression, monitoring was continued for a further 120 min. During the investigation, the hemodynamic situation including transpulmonary thermodilution and blood gases was monitored periodically. RESULTS: During the study, mean arterial pressure remained within the normal range in colloid-treated animals and controls, but was significantly lower in crystalloid-treated animals after decompression of PP. Cardiac output remained within the normal range in the colloid and control groups, but decreased in the crystalloid-treated animals. In the crystalloid group, the lactate concentrations were higher and base excess was lower than in the colloid and control groups at 240 and 300 min (study end). CONCLUSION: This study shows that the negative effects of prolonged PP on hemodynamics and acid-base balance can be obviated by a liberal plasma volume stabilization regimen with colloids.

Laparoscopy vs minilaparotomy and full laparotomy preserves circulatory but not peritoneal and pulmonary immune responses.

PURPOSE: Laparoscopy has been associated with lower inflammatory responses. However, it has been postulated that minilaparotomy, in contrast to full laparotomy, is equally minimally invasive. OBJECTIVE: The aim of this study was to investigate local, systemic, and distant organ immune responses after different surgical approaches to the abdominal cavity, such as minilaparotomy, full laparotomy, and laparoscopy, in a small animal model. METHODS: Male Lewis rats received a permanent central venous catheter and were randomized to 4 groups (n = 6 per group). The animals were subjected to anesthesia alone (control), minilaparotomy (1 cm), full laparotomy (7 cm), or laparoscopy for 60 minutes. Blood was collected via the central venous catheter before as well as 1 hour and 6 hours after the start of intervention. Peritoneal and bronchoalveolar lavages, as well as heart puncture, were performed after 24 hours. RESULTS: All surgical interventions led to a significant migration of polymorphonucleocytes into the abdominal cavity. Full laparotomy resulted in a significant increase in nitric oxide production by peritoneal macrophages as compared with control. Macrophage nitric oxide production after laparoscopy and minilaparotomy was not significantly different. A shift in the expression of OX-6 and CD54 was only detected after full laparotomy. Systemically, O(2)(-) release by circulating mononuclear cells was significantly increased after minilaparotomy and full laparotomy, but not after laparoscopy. The systemic levels of IL6 were significantly accelerated only after full laparotomy, with a maximum after 6 hours. In the lungs, function of alveolar macrophages was not altered in any group. CONCLUSIONS: Any approach to the peritoneal cavity causes local inflammatory responses. Full laparotomy alters peritoneal macrophage functions more pronouncedly than does minilaparotomy or laparoscopy. Systemic inflammatory responses, such as free oxygen radical release, are significantly increased by both minilaparotomy and full laparotomy, whereas laparoscopy preserves systemic immune function. Our results may lead to further preference for the laparoscopic approach over minilaparotomy and full laparotomy.