Augmentation of AAV-mediated cardiac gene transfer after systemic administration in adult rats.

Adeno-associated virus (AAV)-6 or -9-pseudotyped vectors are suitable for efficient cardiac gene transfer after intravenous injection in mice. However, a systemic application in larger animals or humans would require very high doses of viral particles. Therefore, the aim of our study was to test if ultrasound-targeted microbubble destruction could augment cardiac transduction of AAV vectors after intravenous administration in rats. To analyze efficiency and specificity of gene transfer, microbubbles loaded with AAV-6 or -9 harboring a luciferase or enhanced green fluorescent protein (EGFP) reporter gene were infused into the jugular vein of adult Sprague-Dawley rats. During the infusion, high mechanical index ultrasound was administered to the heart. Control rats received the same amount of virus without microbubbles, but with ultrasound. After 4 weeks, organs were harvested and analyzed for reporter gene expression. In contrast to low cardiac expression after systemic transfer of the vector solution without microbubbles, ultrasound-targeted destruction of microbubbles significantly increased cardiac reporter activities between 6- and 20-fold. Analysis of spatial distribution of transgene expression using an AAV-9 vector encoding for EGFP revealed transmural expression predominantly in the left ventricular anterior wall. In conclusion, ultrasound targeted microbubble destruction augments cardiac transduction of AAV vectors in rats. This approach may be suitable for efficient, specific and noninvasive AAV-mediated gene transfer in larger animals or humans.

Effects of endotoxin on serum chemokines in man.

AIM: Endotoxin is known to be a primary initiator of sepsis and septic shock. Migration of immunocompetent cells due to chemotactic attraction plays a central role in the initiation of the immune response. Two major groups of chemokines can be distinguished: C-x-C chemokines like Interleukin-8 attract mainly neutrophils, C-C chemokines (e.g. RANTES) attract monocytes and T-cells. The aim of this study was to get further insight into chemokine profiles after a single endotoxin bolus in man. MATERIALS AND METHODS: We investigated the effect of systemically administered endotoxin (4ng/kg BW i.v.) in 8 healthy volunteers. Clinical data (heart rate, mean arterial pressure, temperature), serum levels of IL-8, and RANTES, as well as white blood cell count were obtained before and hourly for five hours after endotoxin administration. RESULTS: Heart rate and MAP showed significant changes (p<0.05) after 2-3 hours. All volunteers presented with low-grade fever after 2 hours. WBC was elevated 43% and 63% after 4 and 5 hours, respectively. Both chemokines were significantly different from baseline two hours after endotoxin challenge: While IL-8 was significantly increased RANTES serum levels were diminished. CONCLUSION: From our data we conclude that this endotoxin model was effective to mimic the clinical appearance of sepsis. Chemokines like IL-8 and RANTES are integrated in the early immune response to endotoxin challenge in man.

Effects of perioperative recombinant human IFN-gamma (rHuIFN-gamma) application in vivo on T cell response.

In spite of the well-known immunoregulatory effects of recombinant human interferon-gamma (rHuIFN-gamma), in vitro clinical trials in trauma patients remain inconclusive. In vitro studies have shown that IFN-gamma has an effect on lymphocyte responses in addition to immunomodulatory effects on the monocyte/macrophage system. To investigate the in vivo effect of rHuIFN-gamma perioperatively on lymphocyte behavior in surgical patients, we studied 46 anergic patients undergoing major surgery. Treated patients (T, n = 24) received 100 microg rHuIFN-gamma subcutaneously (s.c.), and control patients (C, n = 22) received a placebo on preoperative days -7, -5, and -3 in a controlled, double-blinded placebo trial. Whole blood cultures were stimulated with mitogen on perioperative days, and cytokines were investigated in the supernatants. Interleukin-2 receptor (IL-2R) levels were significantly elevated in the treatment arm during the postoperative period (p < 0.05). The postoperative enhancement of IL-4 in C was completely attenuated in T (p < 0.05). IL-2 levels were elevated perioperatively in T but not in C. No significant effect of rHuIFN-gamma could be demonstrated on IL-10 or lymphocyte proliferation in vitro. From this pilot study, we conclude that preoperative in vivo immunomodulation of lymphocyte function with rHuIFN-gamma in anergic patients is effective. It improves immunoreactivity, as shown by elevated IL-2R levels. Elevated IL-2 and suppressed IL-4 levels indicate a shift toward a Th1-driven lymphocyte response.

[Postoperative endoscopy for the diagnosis and therapy of complications]. / Postoperative Endoskopie zur Diagnose und Therapie von Komplikationen.

A variety of endoscopic methods are available as the main tools in the diagnostics and therapy of various complications after visceral and thoracic surgery. Indications for endoscopic interventions are anastomotic leaks, stenoses, Gl-tract bleedings, biliary lesions and functional problems after surgical procedures. The most common are fibrin sealing of fistulas, dilatation and bougienage, injection therapy for bleeding, bile duct interventions and stent implantations. In most cases operative revisions can be avoided by using endoscopic methods with an overall good success rate. No disadvantages are foreseen following conventional operative interventions if the endoscopic treatment is not successful.

Perioperative treatment with human recombinant interferon-gamma: a randomized double-blind clinical trial.

In spite of proven immunoregulatory effects in vitro of recombinant human interferon-gamma (rhIFN-gamma) in trauma, clinical trials remain inconclusive in such patients. To investigate the in vivo effect of rhIFN-gamma perioperatively in surgical patients we did a pilot study in 46 patients termed anergic by negative delayed-type hypersensitivity (DTH) skin test, who were undergoing major surgery (22 women and 24 men). They received 100 micrograms of rhIFN-gamma subcutaneously (treated [T]; n = 24) in a double-blind, placebo- (control [C]; n = 22) controlled manner on preoperative days -7, -5, and -3. Whole-blood cultures were stimulated on days -7, -1, 4, 7, and 10 for 12 h with or without LPS (1 microgram/mL). Mild side effects such as fever, headache, or chills were observed in 7/24 patients. No major complications occurred and no significant effect of rhIFN-gamma on HLA-DR, IL-1, and IL-8 was demonstrated. PGE2, TNF-alpha and IL-6 levels were elevated perioperatively in T. versus C. Neopterin, a metabolite of activated monocytes and macrophages, was significantly activated on days -1 (C: 7.6 +/- 1.2 versus T: 20.5 +/- 2.4 nmol/mL; P < 0.001), day 1 (C: 8.3 +/- 1.4 nmol/mL versus T: 24.9 +/- 2.8 nmol/mL; P < 0.001), and day 4 (C: 9.5 +/- 1.1 nmol/mL versus T: 16.0 +/- 1.8 nmol/mL; P < 0.05). Due to the overall lack of infectious complications during the investigation, no clinical effect was shown for rhIFN-gamma treatment. DTH skin testing failed to detect high-risk individuals in the patient population studied. In conclusion, we demonstrated in our pilot study that pre-operative immunomodulation with rhIFN-gamma in surgical anergic patients did not show severe side effects and modulated in vitro immunoresponse. A larger clinical trial in better-defined high-risk patients may show whether a reduction of infectious complications can be achieved.

[Surgical techniques in hepatic resections: Ultrasonic aspirator versus Jet-Cutter. A prospective randomized clinical trial]. / Wasserstrahldissektion bei Leberresektion: Ultraschallaspirator versus Jet-Cutter - Eine prospektiv randomisierte Studie -

AIM OF THE STUDY: For all resection-techniques of liver tissue intra- and post-operative blood-loss remains an important problem. Two novel resection-techniques the ultrasound-aspirator (CUSA) and the water-jet dissector (Jet-Cutter) appear to offer significant advantages regarding this problem. Aim of the present prospective clinical study was the comparison of these dissection techniques. MATERIAL AND METHODS: Prospective randomized study with the end points blood-loss, length of surgery, tissue trauma and long-term survival. FINDINGS: Significant differences between both procedures with Jet-Cutter (n = 31) versus ultrasonic surgical aspirator CUSA (n = 30) were observed regarding length of resection and complete liver ischemia time (Pringle-time). Here significant advantages of the jet-cutter-technique were observed with 28 +/- 11 minutes length of resection versus 46 +/- 19 minutes and 29 +/- 12 minutes Pringle-time versus 39 +/- 16 minutes. Furthermore, significant fewer blood transfusions were required following jet-cutter-resection with a mean of 1.5 blood units vs. 2.5 blood units using the CUSA. No differences were observed regarding postoperative long-term survival. CONCLUSIONS: The jet-cutter-technique is a fast and safe surgical procedure for liver resections and offers an attractive therapeutic alternative for various indications in liver surgery.

Interferon-gamma modifies cytokine release in vitro by monocytes from surgical patients.

BACKGROUND: Treatment with interferon-gamma (IFN-gamma), a key mediator for adequate forward-regulatory monocyte immune capability, has been advocated to overcome posttraumatic mononuclear leukocyte paralysis. Conversely, IFN-gamma also is a potent proinflammatory mediator contributing to capillary leakage in sepsis-driven organ failure. The objective of this investigation was to further define the potential of IFN-gamma as a modifier of monocyte activity before and after injury. METHODS: Whole blood samples from 19 patients (7 female and 12 male patients; age, 68 +/- 5 years) before and after cardiac surgery with extracorporeal circulation were incubated under continuous rotation with lipopolysaccharide for 12 hours in the presence or absence of human recombinant IFN-gamma. Pro- and anti-inflammatory cytokines were determined in the plasma. RESULTS: Lipopolysaccharide-induced release of tumor necrosis factor-alpha, interleukin (IL)-6, IL-12, and IL-1Ra, and prostaglandin E2 was clearly augmented with IFN-gamma most strikingly postoperatively (p < 0.05). There was no effect on IL-1beta, neopterin, and soluble tumor necrosis factor-R release. CONCLUSION: Thus there is a wide spectrum of IFN-gamma activity on monocyte activation including anti-inflammatory properties. Since cellular preactivation facilitates monocyte reactivity toward IFN-gamma, we conclude that exogenous administration should be effective but must be carried out with great caution in patients with profound inflammation.