L-arginine: A unique amino acid for improving depressed wound immune function following hemorrhage

Objective: To determine whether L-arginine has any salutary effects on wound immune cell function following trauma-hemorrhage. Background. Depressed wound immune function contributes to an increased incidence of wound infections following hemorrhage. Although administration of L-arginine has been shown to restore depressed cell-mediated immune responses following hemorrhage potentially by maintaining organ blood flow, it remains unknown whether Larginine has any salutary effects on the depressed local immune response at the wound site. Methods: Male mice were subjected to a midline laparotomy and polyvinyl sponges were implanted subcutaneously in the abdominal wound prior to hemorrhage (35 +/- 5 mm Hg for 90 min and resuscitation) or sham operation. During resuscitation mice received 300 mg/kg body weight L-arginine or saline (vehicle). Sponges were harvested 24 h thereafter, wound fluid collected and wound immune cells cultured for 24 h in the presence of LPS. Pro- (IL-1beta, IL-6) and anti-inflammatory (IL-10) cytokines were determined in the supernatants and the wound fluid. In addition, wounds were stained for IL-6 immunohistochemically. In a separate set of animals, skin and muscle blood flow was determined by microspheres. Results: The capacity of wound immune cells to release IL-1beta and IL-6 in vitro was significantly depressed in hemorrhaged mice receiving vehicle. Administration of L-arginine, however, improved wound immune cell function. In contrast, in vivo the increased IL-6 release at the wound site was decreased in L-arginine-treated mice following hemorrhage. Moreover, IL-10 levels were significantly increased in the wound fluid in hemorrhaged animals receiving L-arginine compared to vehicle-treated mice. In addition, the depressed skin and muscle blood flow after hemorrhage was restored by L-arginine. Conclusions: Thus, L-arginine might improve local wound cell function by decreasing the inflammatory response at the wound site. Since L-arginine protected wound immune cell function this amino acid might represent a novel and useful adjunct to fluid resuscitation for decreasing wound complications following hemorrhage. Copyright beta 2002 S. Karger AG, Basel

Bench-to-bedside review: Latest results in hemorrhagic shock

Hemorrhagic shock is a leading cause of death in trauma patients worldwide. Bleeding control, maintenance of tissue oxygenation with fluid resuscitation, coagulation support, and maintenance of normothermia remain mainstays of therapy for patients with hemorrhagic shock. Although now widely practised as standard in the USA and Europe, shock resuscitation strategies involving blood replacement and fluid volume loading to regain tissue perfusion and oxygenation vary between trauma centers; the primary cause of this is the scarcity of published evidence and lack of randomized controlled clinical trials. Despite enormous efforts to improve outcomes after severe hemorrhage, novel strategies based on experimental data have not resulted in profound changes in treatment philosophy. Recent clinical and experimental studies indicated the important influences of sex and genetics on pathophysiological mechanisms after hemorrhage. Those findings might provide one explanation why several promising experimental approaches have failed in the clinical arena. In this respect, more clinically relevant animal models should be used to investigate pathophysiology and novel treatment approaches. This review points out new therapeutic strategies, namely immunomodulation, cardiovascular maintenance, small volume resuscitation, and so on, that have been introduced in clinics or are in the process of being transferred from bench to bedside. Control of hemorrhage in the earliest phases of care, recognition and monitoring of individual risk factors, and therapeutic modulation of the inflammatory immune response will probably constitute the next generation of therapy in hemorrhagic shock. Further randomized controlled multicenter clinical trials are needed that utilize standardized criteria for enrolling patients, but existing ethical requirements must be maintained

Activated partial thromboplastin time waveform analysis as specific sepsis marker in cardiopulmonary bypass surgery

Throughout the last years, several new diagnostic biomarkers have been introduced into clinical routine to identify a systemic inflammatory response syndrome (SIRS) or a septic state and to discriminate between these two entities. According to studies in selected patients, measurement of these biomarkers may be advantageous under certain clinical conditions. On an individual basis, however, these sepsis markers usually lack an adequate negative or positive predictive power. Therefore, physicians in charge still have to rely on a combination of personal experience and results from clinical or laboratory tests when deciding on a patient's therapy. For surgical patients, a key problem consists of the time delay which is associated with the diagnosis of serious postoperative infections and which may negatively affect outcome. It is in this context where the activated partial thromboplastin time waveform analysis may represent a promising new method to discriminate between SIRS and sepsis, thereby shortening the time to therapy. Nevertheless, studies involving large patient populations will be necessary to prove the efficacy of this new diagnostic concept either as a single tool or in combination with the measurement of other biomarkers

Hormônios sexuais influenciam a resposta ao trauma e à sepsis: possíveis soluções terapêuticas

Uma série de estudos clínicos e experimentais demonstram a existência de dimorfismo sexual das respostas imunológicas e orgânicas, bem como da suscetibilidade e morbidade em relação ao choque, ao trauma e à sepse. Respostas imunes celularmente mediadas apresentam-se deprimidas em machos em resposta ao binômio trauma-hemorragia, mas conservados/enaltecidos em fêmeas em proestro. Adicionalmente demonstra-se que os hormônios sexuais são responsáveis por esta dicomotomia de resposta sexualmente específica, em condições cardiovasculares adversas. Estudos específicos indicam que os andrógenos produzem imunodepressão pós-trauma hemorragia em machos. Em contraste, esteróides sexuais femininos parecem exibir propriedades imunoprotetoras após episódios de trauma com ou sem perda importante de sangue. No terreno dos mecanismos subjacentes, foram identificados receptores para hormônios sexuais em várias células do sistema imunológico, sugerindo a existência de efeitos diretos destes hormônios sobre tais células. Alternativamente, observam efeitos indiretos de hormônios sexuais tais como modulação das respostas cardiovasculares das enzimas sintetizadores de andrógeno e estrógeno, que podem contribuir para as estas respostas sexualmente diferenciadas. Estudos recentes indicam que os hormônios sexuais, como por exemplo a dehidroepiandrosterona também modulam a função de células mononucleares da série branca em pacientes cirúrgicos. Assim, as propriedades imunomodulatórias de hormônios sexuais/antagonistas de receptores/enzimas sintetizadores de esteróides após a ocorrência de trauma ou de hemorragia sugerem o caminho para novas estratégias terapêuticas para o tratamento de imunodepressão em pacientes cirúrgicos.Several clinical and experimental studies have demonstrated gender dimorphism in immune and organ responsiveness and in the susceptibility to and morbidity from shock, trauma, and sepsis. In this respect, cell-mediated immune responses have been shown to be depressed in males following trauma-hemorrhage, whereas they were aintained/enhanced in proestrus females. Furthermore, sex hormones have been shown to be responsible for this gender-specific immune response following adverse circulatory conditions. More specifically, studies indicate that androgens produce immunodepression following trauma-hemorrhage in males. In contrast, female sex steroids appear to exhibit immunoprotective properties following trauma and severe blood loss. With regard to the underlying mechanisms, receptors for sex hormones have been identified on various immune cells suggesting direct effects of these hormones on the immune cells. Alternatively, indirect effects of sex hormones, ie, modulation of cardiovascular responses or androgen- and estrogen-synthesizing enzymes, might contribute to gender-specific immune responses. Recent studies indicate that sex hormones, eg, dehydroepiandrosterone (DHEA), also modulate the function of peripheral blood mononuclear cells in surgical patients. Thus, the immunomodulatory properties of sex hormones/receptor antagonists/sex steroid synthesizing enzymes following trauma-hemorrhage suggests novel therapeutic strategies for the treatment of immunodepression in surgical patients

The potential role of T-cells and their interaction with antigen-presenting cells in mediating immunosuppression following trauma-hemorrhage

Objective: Trauma-hemorrhage results in depressed immune responses of antigen-presenting cells (APCs) and T-cells. Recent studies suggest a key role of depressed T-cell derived interferon (IFN)-g in this complex immune cell interaction. The aim of this study was to elucidate further the underlying mechanisms responsible for dysfunctional T-cells and their interaction with APCs following trauma-hemorrhage. Design: Adult C3H/HeN male mice were subjected to trauma-hemorrhage (3-cm midline laparotomy) followed by hemorrhage (blood pressure of 35�5mmHg for 90 min and resuscitation) or sham operation. At 24 h thereafter, spleens were harvested and T-cells (by Microbeads) and APCs (via adherence) were Isolated. Co-cultures of T-cells and APCs were established for 48 h and stimulated with concanavalin A and lipopolysaccharide. T-Cell specific cytokines known to affect APC function (i.e. interleukin(IL)-2, IL-4 and granulocyte-macrophage colony-stimulating factor (GM-CSF)) were measured in culture supernatants by Multiplex assay. The expression of MHC class II as well as co-stimulatory surface molecules on T-cells and APCs was determined by flow cytometry. Results: The release of IL-4 and GM-CSF by T-cells was suppressed following trauma-hemorrhage, irrespective of whether sham or trauma-hemorrhage APCs were present. Antigen-presenting cells from animals subjected to trauma-hemorrhage did not affect T-cell derived cytokine release by sham T-cells. In contrast, T-cells from traumahemorrhage animals depressed MHC class II expression of CD11c(þ) cells, irrespective of whether APCs underwent sham or trauma-hemorrhage procedure. Surprisingly, co-stimulatory molecules on APCs (CD80, CD86) were not affected by trauma-hemorrhage. Conclusions: These results suggest that beside IFN-g other T-cell derived cytokines contribute to immunosuppression following trauma-hemorrhage causing diminished MHC II expression on APCs. Thus, T-cells appear to play an important role in this interaction at the time-point examined. Therapeutic approaches should aim at maintenance of T-cell function and their interaction with APCs to prevent extended immunosuppression following trauma-hemorrhage

Quality of life in peritoneal carcinomatosis: A prospective study in patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC)

BACKGROUND/AIMS Cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion (HIPEC) can improve survival in selected patients with peritoneal carcinomatosis, but bear a significant risk of perioperative morbidity. The aim of this study was to prospectively evaluate the quality of life (QoL) following cytoreduction and HIPEC. METHODS In this study including 40 patients (65% females) with different primary tumors, the EORTC QLQ-C30 questionnaire was applied prior to CS and HIPEC as well as 3, 9, and 18 months postoperatively. RESULTS Global health status was not impaired significantly following HIPEC. Scales and symptom scores that deteriorated 3 months postoperatively (p < 0.05), that is, physical, role, and social functions as well as fatigue, pain, dyspnea, insomnia, and diarrhea, all returned to preoperative values within 9 months. CONCLUSIONS Following cytoreductive surgery and HIPEC, QoL returns to preoperative levels within 9 months. Selected patients that are likely to benefit oncologically from HIPEC should not be denied this option for fear of reduced postoperative QoL

A long road ahead

Background: Climate change may well be the “largest threat” to humankind. Changes to our climate system lead to a decrease in global health. The healthcare sector presents one of the largest carbon footprints across all industries. Since surgical departments have one of the largest carbon footprints within the healthcare sector, they represent an area with vast opportunities for improvement. To drive change, it is vital to create awareness of these issues and encourage engagement in changes among people working in the healthcare industry. Methods: We conducted an anonymous cross-sectional survey study to assess awareness among surgeons regarding the impact of healthcare systems on climate change. The questions were designed to investigate surgeons’ willingness to accept and promote changes to reduce carbon footprints. Participants included surgical professionals of all ages and levels of expertise. Results: A total of 210 participants completed the survey in full and were included in the evaluation. Sixty percent emphasized a lack of information and the need for personal education. Over 90 % expressed concern for the environment and a strong desire to gain new insights. Provided that clinical performance remains the same, more than 70 % are willing to embrace carbon-friendly alternatives. In this context, all participants accepted the additional time required for training and initially increased personal efforts to achieve equal performance. Conclusion: Limited awareness and information about carbon footprints were observed in surgical departments in German hospitals. Nevertheless, the vast majority of surgeons across all age groups are more than willing to acquire new insights and adapt to changes in order to reduce energy consumption and carbon dioxide production

Association of differential miRNA expression with hepatic vs. peritoneal metastatic spread in colorectal cancer

Background: Though peritoneal carcinomatosis reflects a late stage of colorectal cancer (CRC), only few patients present with synchronous or metachronous liver metastases alongside their peritoneal carcinomatosis. It is hypothesized that this phenomenon may be causally linked to molecular characteristics of the primary CRC. This study used miRNA profiling of primary CRC tissue either metastasized to the liver, to the peritoneum or not metastasized at all thus to identify miRNAs potentially associated with defining the site of metastatic spread in CRC. Methods: Tissue of the primary tumor stemming from CRC patients diagnosed for either liver metastasis (LM; n = 10) or peritoneal carcinomatosis (PER; n = 10) was analyzed in this study. Advanced CRC cases without metastasis (M0; n = 3) were also included thus to select on those miRNAs most potentially associated with determining metastatic spread in general. miRNA profiling of 754 different miRNAs was performed in each group. MiRNAs being either differentially expressed comparing PER and LM or even triple differentially expressed (PER vs. LM vs. M0) were identified. Differentially expressed miRNAs were further validated by in silico and functional analysis. Results: Comparative analysis identified 41 miRNAs to be differentially expressed comparing primary tumors metastasized to the liver as opposed to those spread to the peritoneum. A set of 31 miRNAs was significantly induced in primary tumors that spread to the peritoneum (PER), while the remaining 10 miRNAs were found to be repressed. Out of these 41 miRNAs a number of 25 miRNAs was triple-differentially expressed (i.e. differentially expressed comparing LM vs. PER vs. M0). The latter underwent in silico analysis. Finally, we demonstrated that miR-31 down-regulated c-MET in DLD-1 colon cancer cells. Conclusions: This study demonstrates that CRC primary tumors spread to the peritoneum vs. metastasized to the liver display significantly different miRNA profiles. Larger patient cohorts will be needed to validate whether determination of e.g. miR-31 may aid to predict the course of disease and whether this may help to create individualized follow up or treatment protocols. To determine whether certain miRNAs may be involved in regulating the metastatic potential of CRC, functional studies will be essential