Angiotensin II inhibits interleukin-6 mRNA expression of LPS-stimulated macrophages through down-regulating calcium signaling.

BACKGROUND: The renin-angiotensin system plays a key role in the regulation of blood pressure following hemorrhage and shock. Recent studies also suggest renin-angiotensin system regulates inflammatory mediator production although the amechanism is largely unknown. This purpose of the study was to examine the effect of angiotensin II on macrophage (MØ) IL-6 messenger RNA (mRNA) expression induced by lipopolysaccharide (LPS) and on the alterations in the calcium influx. METHODS: J774A.1 cells, a mouse MØ cell line, were exposed to E. coli LPS (1 or 10 µg/ml) in the presence of angiotensin II (10 nM to 1 µM). IL-6 mRNA expression was determined by the reverse transcription polymerase chain reaction technique. IL-6 protein production was measured by ELISA. To examine the involvement of calcium signaling in IL-6 mRNA expression, MØ were exposed to various calcium agonists and antagonists in the presence of LPS stimulation. Changes of intracellular [Ca(2+)] by LPS stimulation and angiotensin II treatment were determined by a fura-2 fluorescence ratio method. RESULTS: LPS stimulation increased MØ IL-6 mRNA expression, which was inhibited by Angiotensin II in a dose-dependent fashion. Both thapsigargin and A23187 augmented the IL-6 mRNA levels induced by LPS stimulation, but only thapsigargin was able to induce IL-6 mRNA directly. TMB-8 but not verapamil inhibited LPS-stimulated MØ IL-6 mRNA. Finally, angiotensin II significantly altered the changes in intracellular [Ca(2+)] levels induced by LPS stimulation by reducing both the peak and slope of calcium spikes. CONCLUSIONS: Our data show that calcium signaling is closely related to IL-6 mRNA expression. Angiotensin II inhibits IL-6 mRNA expression of LPS-stimulated MØ. The inhibitory effects of angiotensin II appear, at least in part, to be mediated through down regulating calcium dependent pathways.

Measuring brain temperature while maintaining brain normothermia in patients with severe traumatic brain injury.

The aim of this study was to evaluate the relationship between superficial temporal artery temperature (Tt), rectal temperature (Tr) and intracranial temperature (ICT) when attempting to keep the brain in a normothermic condition in patients with severe traumatic brain injury (TBI). We also compared the incidence of temperature gradient reversal in patients who survived (survivors) and patients who did not (non-survivors) and the difference in temperature gradient reversal between survivors and non-survivors. Tr is normally lower than and ICT and temperature gradient reversal, when Tr exceeds ICT, has been demonstrated to be an early sign of brain death. A total of 28 patients with severe TBI were enrolled retrospectively in our study between November 2008 and February 2010. Each patient's Tt, Tr and ICT was recorded every hour for 4 days. Our results show that the frequency of brain hyperthermia in our participants (ICT>38°C) was 17.7%. Using a paired t-test and Bland-Altman plots, it was shown that a significant temperature difference existed between Tt, Tr and ICT (p<0.001). The use of Spearman's correlation method revealed that Tt, Tr and ICT were positively correlated (p<0.001). Brain death occurred in five patients at a mean of 9.6 hours (range: 8-12 hours) after a temperature gradient reversal between Tt, Tr and ICT. Fisher's exact test showed that there was a significant difference in the incidence of temperature gradient reversal between Tt, Tr and ICT in survivors and non-survivors (p<0.001). We conclude that a significant temperature difference exists between Tt, Tr and ICT when maintaining brain normothermia. The daily practice of non-invasive Tt measurement may cause doctors to underestimate ICT; reversal of the ICT and Tt and/or Tr temperatures could be an early marker of a poor prognosis for patients with severe TBI.

Prognostic predictors of outcome in an operative series in traumatic brain injury patients.

BACKGROUND: Although several prognostic factors for traumatic brain injury (TBI) have been evaluated, a useful predictive scoring model for outcome has yet to be developed for TBI patients. The aim of this study was to determine independent predictors and develop a multivariate logistic regression equation to determine prognosis in TBI patients. METHODS: A total of 13 different variables were evaluated. All 84 patients in this study were retrospectively evaluated between October 2003 and January 2008 and all underwent craniectomy or craniotomy for hematoma removal and were fitted with intracranial pressure (ICP) microsensor monitors. By using univariate, multiple logistic regression and prognostic regression scoring equations it was possible to draw Receiver-Operating Characteristic curves (ROC) to predict Glasgow Outcome Scale (GOS) 6 months after TBI. RESULTS: We found that patients over 40 years of age (p < 0.001), unresponsive pre-op pupil reaction (p =0.001), pre-op midline shift (p =0.008), higher injury severity score (ISS; p=0.007), and craniectomy (p < 0.05) were associated with poor outcome in patients with TBI. Using ROC curve to predict the probability of unfavorable outcome, the sensitivity was 97.5% and the specificity was 90.7%. CONCLUSION: In our preliminary findings, five variables to predict poor outcomes 6 months after TBI were useful. These sensitive variables can be used as a referential guideline in our daily practice to decide whether or not to perform advanced management or avoid decompressive craniectomy.

Agmatine-promoted angiogenesis, neurogenesis, and inhibition of gliosis-reduced traumatic brain injury in rats.

BACKGROUND: The mechanisms of agmatine-induced neuroprotective effects in traumatic brain injury (TBI) remain unclear. This study was to test whether inhibition of gliosis, angiogenesis, and neurogenesis attenuating TBI could be agmatine stimulated. METHODS: Anesthetized rats were randomly assigned to sham-operated group, TBI rats treated with saline (1 mL/kg, intraperitoneally), or TBI rats treated with agmatine (50 mg/kg, intraperitoneally). Saline or agmatine was injected 5 minutes after TBI and again once daily for the next 3 postoperative days. RESULTS: Agmatine therapy in rats significantly attenuated TBI-induced motor function deficits (62° vs. 52° maximal angle) and cerebral infarction (88 mm vs. 216 mm), significantly reduced TBI-induced neuronal (9 NeuN-TUNEL double positive cells vs. 60 NeuN-TUNEL double positive cells) and glial (2 GFAP-TUNEL double positive cells vs. 20 GFAP-TUNEL double positive cells) apoptosis (increased TUNEL-positive and caspase-3-positive cells), neuronal loss (82 NeuN-positive cells vs. 60 NeuN-positive cells), gliosis (35 GFAP-positive cells vs. 72 GFAP-positive cells; 60 Iba1-positive cells vs. 90 Iba1-positive cells), and neurotoxicity (30 n-NOS-positive cells vs. 90 n-NOS-positive cells; 35 3-NT-positive cells vs. 90 3-NT-positive cells), and significantly promoted angiogenesis (3 BrdU/endothelial cells vs. 0.5 BrdU/endothelial cells; 50 vascular endothelial growth factor positive cells vs. 20 vascular endothelial growth factor-positive cells) and neurogenesis (27 BrdU/NeuN positive cells vs. 15 BrdU/NeuN positive cells). CONCLUSIONS: Resultantly, agmatine therapy may attenuate TBI in rats via promoting angiogenesis, neurogenesis, and inhibition of gliosis.

Attenuation of brain nitrostative and oxidative damage by brain cooling during experimental traumatic brain injury.

The aim of the present study was to ascertain whether brain cooling causes attenuation of traumatic brain injury by reducing brain nitrostative and oxidative damage. Brain cooling was accomplished by infusion of 5 mL of 4°C saline over 5 minutes via the external jugular vein. Immediately after the onset of traumatic brain injury, rats were randomized into two groups and given 37°C or 4°C normal saline. Another group of rats were used as sham operated controls. Behavioral and biochemical assessments were conducted on 72 hours after brain injury or sham operation. As compared to those of the sham-operated controls, the 37°C saline-treated brain injured animals displayed motor deficits, higher cerebral contusion volume and incidence, higher oxidative damage (e.g., lower values of cerebral superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase, but higher values of cerebral malondialdehyde), and higher nitrostative damage (e.g., higher values of neuronal nitric oxide synthase and 3-nitrotyrosine). All the motor deficits and brain nitrostative and oxidative damage were significantly reduced by retrograde perfusion of 4°C saline via the jugular vein. Our data suggest that brain cooling may improve the outcomes of traumatic brain injury in rats by reducing brain nitrostative and oxidative damage.

Partial splenectomy using an electromagnetic thermal surgery system in a porcine model.

PURPOSE: Partial splenectomy is technically more complicated than total splenectomy due to difficulty in haemostasis, but it can preserve splenic function after operation. We evaluated the feasibility and safety of partial splenectomy performed by an electromagnetic thermal surgery system in a porcine model. METHODS: Our system was comprised of an alternating electromagnetic field generator, an extensible coil applicator, comb-needle arrays, and a temperature feedback control component. Ten Lanyu pigs were anaesthetised to conduct partial splenectomy. Two rows of comb-like stainless-steel needle arrays were inserted into the tissue at 15 cm from the distal tip of the spleen. The temperature of the tissues around the needle arrays was raised to 150°C for 3 min and the spleen was transected directly between the needle arrays and then sent for histological examination. Two weeks later, the animals underwent a second celiotomy to remove the remaining spleen for histological examination. RESULTS: The average duration of the partial splenectomy was 10 min as timed from insertion of the needle arrays to the transection of the spleen. There was no blood loss during the procedure. The cut surface of the spleen was well coagulated without any oozing sites. During the re-exploration, no intra-abdominal blood was found. There were dense adhesions between the spleen and the surrounding organs. Histological examination of the cut surface of the excised portion of the spleen showed coagulative necrosis with clot formation in the blood vessels. CONCLUSIONS: Partial splenectomy using our electromagnetic thermal system can achieve effective haemostasis and is safe and easy to perform.

Brain cooling-stimulated angiogenesis and neurogenesis attenuated traumatic brain injury in rats.

BACKGROUND: Although brain cooling has been reported to be effective in improving the outcome after traumatic brain injury (TBI) in rats, the mechanisms of brain cooling-induced neuroprotective actions remain unclear. This study was to test whether angiogenesis and neurogenesis attenuating TBI could be brain cooling stimulated. METHODS: Anesthetized rats, immediately after the onset of TBI, were divided into two groups and given the brain cooling (infusing 5 mL of 4°C saline via the external jugular vein) or no brain cooling (infusing 5 mL of 37°C saline via the external jugular vein). RESULTS: Brain cooling without interference with the core temperature in rats significantly attenuated TBI-induced cerebral infarction (90 mm³ vs. 250 mm³) and motor (61 degrees vs. 57 degrees maximal angle) and proprioceptive (14% vs. 42% maximal possible effect) function deficits, significantly reduced TBI-induced neuronal (24 vs. 62 neuronal-specific nuclear [NeuN]-TUNEL double-positive cells) and glial (5 vs. 35 GFAP-TUNEL double-positive cells) apoptosis (increased TUNEL-positive and caspase-3-positive cells), neuronal loss (102 vs. 66 NeuN-positive cells), and gliosis (40 vs. 66 GFAP-positive cells; 66 vs. 89 Iba1-positive cells), and significantly promoted angiogenesis (5-bromodeoxyuridine [BrdU]/endothelial cells vs. 1-BrdU/endothelial cell; 58 vs. 31 vascular endothelial growth factor-positive cells), and neurogenesis (33 vs. 14 BrdU/NeuN positive cells). CONCLUSIONS: Brain cooling-stimulated angiogenesis and neurogenesis attenuated a fluid percussion TBI in rats.

Early selective angioembolization improves success of nonoperative management of blunt splenic injury.

The role of angioembolization in the management of patients with blunt spleen injury is still under debate. Our study examined the impact of splenic artery embolization (SAE) on the outcome of such patients. We reviewed 114 consecutive blunt abdominal trauma patients with isolated splenic injury over a period of 40 months, including 61 patients seen before (Group A) and 53 patients seen after (Group B) the adoption of SAE. Hemodynamically unstable patients underwent the abdominal exploration and stable patients were evaluated with CT scans of abdomen and pelvis. Patients underwent SAE based on the findings of CT scans, including contrast extravasation or large hemoperitoneum. For initially stable patients, there were no differences in nonoperative management success rate between Groups A and B in regards to injury severity score > or =16, age, or grades of splenic injury > or =3. In comparison, among patients with large hemoperitoneum found by abdominal CT, Group B had significantly better nonoperative management success rates (P < 0.05). SAE was successful to control bleeding in 80 per cent of patients. Partial splenic infarction was noted in all patients after the procedure but it resolved by six months. By using criteria developed based on abdominal CT scans for angioembolization, we are able to improve nonoperative splenic salvage rate.

Resuscitation from experimental traumatic brain injury by agmatine therapy.

Both nitric oxide and glutamate contribute to ischaemic brain injury. Agmatine inhibits all isoforms of nitric oxide synthase and blocks N-methyl-d-aspartate receptors. In this study, we gave agmatine intraperitoneally and assessed its effect on fluid percussion brain injury in rats. Anaesthetised rats, immediately after the onset of fluid percussion traumatic brain injury (TBI), were divided into two major groups and given the vehicle solution (1mL/kg) or agmatine (50mg/kg) intraperitoneally. Mean arterial pressure, intracranial pressure, cerebral perfusion pressure, and levels of glutamate, nitric oxide, lactate/pyruvate ratio, and glycerol in hippocampus were monitored continuously within 120min after TBI. The weight loss was determined by the difference between the first and third day of body weight after TBI. The maximal grip angle in an inclined plane was measured to determine motor performance whereas the percent of maximal possible effect was used to measure blockade of proprioception. The triphenyltetrazolium chloride staining procedures were used for cerebral infarction assay. Compared to those of the sham-operated controls, the animals with TBI had higher values of extracellular levels of glutamate, nitric oxide, lactate-to-pyruvate ratio, and glycerol in hippocampus and intracranial pressure, but lower values of cerebral perfusion pressure. Agmatine administered immediately after TBI significantly attenuated the TBI-induced increased hippocampal levels of glutamate, nitric oxide, lactate-to-pyruvate ratio, and glycerol, intracranial hypertension, and cerebral hypoperfusion. In addition, the TBI-induced cerebral infarction, motor and proprioception deficits, and body weight loss evaluated 3 days after TBI were significantly attenuated by agmatine therapy. The present data indicate that agmatine may attenuate TBI by reducing the excessive accumulation of both glutamate and nitric oxide in the brain.

Management of pulseless and apneic trauma patients: are aggressive measures justified?

This study prospectively examined the care of trauma patients in extremis on presentation to a tertiary medical center between January 2000 and August 31, 2002. There were 144 patients who presented without a pulse or spontaneous respiration and required cardiopulmonary resuscitation (mean age, 41.5+/-2.3 years; male-to-female ratio, 105:39). Successfully resuscitated patients, who were either admitted to the surgical intensive care unit (SICU) or who were taken to the operating room for surgical exploration, had significantly shorter duration of cardiopulmonary resuscitation (14.55+/-1.64 minutes vs. 33.32+/-1.23 minutes; P < 0.001) and received less amounts of epinephrine than those who died in the emergency room (P < 0.05). One hundred sixteen patients died in the emergency room. Nineteen admitted patients died within 24 hours of presentation. Nine patients survived beyond 24 hours and all of them were admitted directly to the SICU for the management of brain injury. Six patients were taken to the operating room for surgical exploration to control the bleeding; all of them died in the operating room or shortly thereafter in the SICU. No patient in this study survived to be discharged. The financial cost of successfully resuscitated patients was significantly higher than that of patients who died in the emergency room (P < 0.001). Instead of insisting on aggressive measures to resuscitate trauma patients in extremis on presentation, the authors suggest we should redirect that fervor toward efforts made to promote trauma awareness and injury prevention programs.

Splenic abscess: an easily overlooked disease?

Splenic abscess is an uncommon but potentially life-threatening disease. Recent advances in radiology have affected the diagnosis and management of this disease entity. The purpose of this study was to review our experience in managing these patients. We retrospectively reviewed the medical records of 51 patients with splenic abscess as seen in a tertiary medical center between 1998 and 2003. We analyzed the demographics, clinical manifestations, etiology, predisposing factors, diagnostic modalities, bacteriologic profile, treatment, and outcome of these patients. The mean age was 59.9 +/- 14.2 years (ranging from 21-89 years). The male:female ratio was 29:22. Common symptoms included fever (82%), abdominal pain (71%), and nausea and vomiting (46%). The majority of these patients (83%) had leukocytosis. Thirty-six patients had associated parenchymal liver diseases and 26 patients had diabetes mellitus. Abdominal sonogram or computed tomography was performed to establish the diagnosis. Most cultures from the abscess cavities grew gram-negative enteric bacilli. Patients were treated with antimicrobial therapy only (n = 33), additional percutaneous drainage with a pigtail catheter (n = 11), or splenectomy (n = 7), and the survival rates were 48 per cent, 45 per cent, and 100 per cent, respectively. Splenic abscess should be considered in a patient with fever, left upper abdominal pain, and leukocytosis. Splenectomy appears to have better treatment outcome than percutaneous drainage or intravenous antibiotics alone.

Selective intraoperative cholangiography and single-stage management of common bile duct stone in laparoscopic cholecystectomy.

BACKGROUND: There are still debates and controversies in the detection and the management of common bile duct (CBD) stones in the era of laparoscopic cholecystectomy (LC). This prospective study was performed to evaluate a single-stage management of CBD stone during LC. METHODS: Between May 1998 and January 2000, 249 consecutive patients with gallstone and cholecystitis were enrolled in this study. The mean age was 52.5 +/- 12.4 years. Male to female ratio was 106:143. All patients underwent abdominal sonography and the determination of the serum biochemical profile preoperatively. Patients presented with sepsis or with total bilirubin > or = 6 ng/dL were excluded from the study. RESULTS: 244 (98%) patients underwent LC and 5 (2%) patients were converted to open cholecystectomy. Intraoperative cholangiogram (IOC) was only performed in patients who fulfilled our predetermined criteria. Among 90 patients who had IOC, only 23 patients had CBD stones that were removed either by transcystic duct stone extraction (61%) or CBD exploration (39%). The additional procedures to remove CBD stone did not prolong the hospitalization. There were four wound infections and one cystic stump leakage. One patient developed CBD stone during the follow-up period up to 37 months. CONCLUSIONS: Our study indicates that routine use of IOC during LC is not necessary. In addition, single-stage approach for the management of CBD stone during LC is feasible and should be considered by laparoscopic surgeons.

Upregulation of cyclooxygenase-II gene and PGE2 production of peritoneal macrophages in diabetic rats.

BACKGROUND: Patients with diabetes mellitus have increased risk of developing infectious complications following trauma and surgery. Recent studies have attributed altered immunoinflammatory responses of these patients as the cause of the underlying pathophysiology. This study was designed to investigate the effect of hyperglycemia on tissue-fixed macrophages (MO) PGE2 production. METHODS: Experimental hyperglycemia was induced in Sprague-Dawley rats by intraperitoneal injection of streptozotocin (65 mg/kg). Peritoneal MO were harvested and stimulated with Escherichia coli LPS (1 ng to 1 microg/ml). COX-2 mRNA expression was measured by RT-PCR with specific primers. PGE2 production by peritoneal MO was determined by ELISA. In addition, the effect of hyperglycemia on NFkappaB activation and pro-inflammatory cytokines induced by LPS were studied on RAW 264.7 cells cultured in media with either 5.5 mm or 25 mm of glucose. RESULTS: LPS stimulation induced a dose-dependent response of PGE2 production and COX-2 mRNA expression. MO from diabetic animals produced more COX-2 mRNA and PGE2 than the control animals. LPS stimulation induced NFkappaB activation that was attenuated by hyperglycemia in RAW cells. Similarly, hyperglycemia reduced the production of TNF and IL-6. CONCLUSIONS: Our data suggest that hyperglycemia alters LPS-stimulated macrophage responses by augmenting anti-inflammatory activities such as PGE2. In addition, hyperglycemia also reduces NFkappaB activity and NFkappaB-dependent cytokines production.

Endoscope-assisted laparoscopic repair of perforated peptic ulcers.

Laparoscopic repairs for perforated peptic ulcer (PPU) are likely to fail in patients with shock, gastric outlet obstruction, or large perforations. This prospective study was performed to evaluate a revised approach of laparoscopic repair with endoscopic assistance to treat these patients. Between April 2001 and February 2002, 30 consecutive patients with PPU were enrolled in this study. The mean age was 43.1 +/- 12.2 years. Male to female ratio was 27:2. One patient was excluded from laparoscopic repair due to a gastric outlet obstruction. The other 29 patients were managed according to a protocol of preoperative upper endoscopy and laparoscopic intracorporeal suture repair with an omental patch. The average operative time was 58.1 +/- 13.5 minutes (range, 36-96 min). The average diameter of perforation was 4.2 +/- 2.0 mm (range, 1-12 mm). The average time to resume oral fluids was 3.2 +/- 0.8 days (range, 2-8 days). The average hospital stay was 4.7 +/- 1.1 days (range, 3-10 days). There was no leakage or mortality. Most patients did not receive parenteral analgesics postoperatively. We conclude that endoscope-assisted laparoscopic repair for PPU is safe and effective. This revised technique allows surgeons to exclude patients who are likely to fail the laparoscopic repair.

Levamisole modulates prostaglandin E2 production and cyclooxygenase II gene expression in human colonic cancer cells.

BACKGROUND: Colorectal adenocarcinoma is one of the leading causes of cancer mortality in the world. Recent studies have demonstrated that prostaglandin E(2) (PGE(2)) and cyclooxygenase (COX) are involved in the early development of colorectal cancer. Levamisole together with 5-fluorouracil has been shown to improve the survival of patients with Duke's C colon cancer. This study examined the effect of levamisole on PGE(2) production and COX-2 gene activation in immortalized human colon cells. MATERIALS AND METHODS: Colon 205 cells, a human colonic cancer cell line, were exposed to Escherichia coli LPS (1 microg/mL) in the presence of levamisole (1 microm to 1 mm). The PGE(2) production was determined by enzyme-linked immunosorbent assay. In addition, cyclooxygenase II (COX-2) mRNA expression and COX-2 protein were measured by the real-time reverse transcription polymerase chain reaction and Western blot assay, respectively. Transcription factor nuclear factor (NF)-kappaB activity of the nuclear and cytoplasmic proteins was determined by Western blot assay with a P65 antibody. RESULTS: Colon 205 cells produced significantly more PGE(2) when stimulated by LPS. Levamisole inhibited PGE(2) production by LPS-stimulated colon 205 cells in a dose-dependent fashion. In addition, COX-2 mRNA expression and COX-2 protein induced by LPS were also reduced by levamisole. Finally, NF-kappaB activation of LPS-stimulated colon cells was inhibited by levamisole. CONCLUSION: Levamisole inhibits PGE(2) production by LPS-stimulated colon 205 cells. The inhibition of levamisole occurs at the transcription level of COX-2 gene and is regulated through NF-kappaB activation.

MAPK regulation of prostaglandin E2 production by lipopolysaccharide-stimulated macrophages is not dependent on nuclear factor kappaB.

BACKGROUND: Prostaglandin E2 (PGE2) is a major contributor to the production and maintenance of immunosuppression in injured and septic patients. Although the synthesis of PGE2 by various enzymes has been elucidated, the regulatory mechanism of these enzymes is not clear. The purpose of this study was to determine the role of MAPK cascades in COX-2 gene activation by lipopolysaccharide (LPS)-stimulated macrophages (Mphi). MATERIALS AND METHODS: RAW 264.7 cells, a mouse Mphi cell line, were exposed to Escherichia coli LPS (10 microg/ml) in the presence of PD98059, a selective inhibitor of MAPKP44/P42, and SB202190, a selective inhibitor of MAPKP38. COX-2 mRNA expression and PGE2 production were measured by Northern Blot assay and ELISA, respectively. Mphi nuclear factor (NF)kappaB and cAMP-response element (CRE) activities were determined by electrophoretic mobility shift assays. RESULTS: LPS stimulation increased Mphi COX-2 mRNA expression and PGE2 production. PD98059 or SB202190 attenuated LPS-induced COX-2 mRNA as well as PGE2 production in a dose-dependent fashion. Inhibition of MAPKP44/P42 or MAPKP38 had no effect on NFkappaB activation but reduced CRE activity induced by LPS stimulation. CONCLUSION: Our data show that MAPK cascades regulate COX-2 gene expression and PGE2 production in LPS-stimulated Mphi through NFkappaB independent pathways. The regulatory mechanism is likely to be mediated through CRE.