Severity of trauma changes expression of TNF-alpha mRNA in the brain of mice

Inflammatory response to the ischaemia-reperfusion insult in the liver after major tissue trauma

BACKGROUND

Polytrauma is often accompanied by ischaemia-reperfusion injury to tissues and organs, and the resulting series of immune inflammatory reactions are a major cause of death in patients. The liver is one of the largest organs in the body, a characteristic that makes it the most vulnerable organ after multiple injuries. In addition, the liver is an important digestive organ that secretes a variety of inflammatory mediators involved in local as well as systemic immune inflammatory responses. Therefore, this review considers the main features of post-traumatic liver injury, focusing on the immuno-pathophysiological changes, the interactions between liver organs, and the principles of treatment deduced.

METHODS

We focus on the local as well as systemic immune response involving the liver after multiple injuries, with emphasis on the pathophysiological mechanisms.

RESULTS

An overview of the mechanisms underlying the pathophysiology of local as well as systemic immune responses involving the liver after multiple injuries, the latest research findings, and the current mainstream therapeutic approaches.

CONCLUSION

Cross-reactivity between various organs and cascade amplification effects are among the main causes of systemic immune inflammatory responses after multiple injuries. For the time being, the pathophysiological mechanisms underlying this interaction remain unclear. Future work will continue to focus on identifying potential signalling pathways as well as target genes and intervening at the right time points to prevent more severe immune inflammatory responses and promote better and faster recovery of the patient.

Ultrasound-guided rectus sheath block for single-incision laparoscopic cholecystectomy

INTRODUCTION

Single-incision laparoscopic cholecystectomy (SILC) is increasingly applied for cholecystectomy and has been reported as safe and feasible, with short-term operative outcomes equivalent to four-port cholecystectomy. Although many investigators in randomized studies have noted the cosmetic advantages of SILC, the benefit of decreased pain in SILC remains controversial. Therefore, this study aimed to assess the efficacy of the rectus sheath block in SILC with respect to subjective pain.

METHODS

From April 2010 to March 2012, 75 patients with symptomatic gallstone or gallbladder polyps were assigned to one of three groups: (i) four-port laparoscopic cholecystectomy (n = 29); (ii) SILC (n = 15); and (iii) rectus sheath block in SILC (n = 30). We evaluated the operative details, length of hospital stay, and the need and usage of analgesia. Postoperative pain was recorded at 2, 6, 12, and 24 h after surgery based on a visual analog scale.

RESULTS

There was no difference with regard to age, ASA score, BMI, duration of operation, or length of hospital stay among the three groups. A significantly lower pain score was observed in the rectus sheath block in SILC group than in the SILC group at 2 and 6 h after operation. The pain score and need for analgesia were similar between the SILC group and the four-port cholecystectomy group.

CONCLUSION

SILC using an ultrasound-guided rectus sheath block significantly reduces postoperative pain.

Splenic Doppler resistive index for early detection of occult hemorrhagic shock after polytrauma in adult patients

The objective of this study was to evaluate whether direct assessment of splenic circulation by splenic Doppler resistive index (Doppler RI) is a clinically useful noninvasive method for an early detection of occult hemorrhagic shock after polytrauma in adult patients. Splenic Doppler RI was measured in 49 hemodynamically stable adult patients admitted to the emergency department because of polytrauma. Renal Doppler RI was also determined in 20 patients. Spleen size, Injury Severity Score, systolic blood pressure, heart rate, blood lactate, standard base excess, pH, hemoglobin, and inferior vena cava diameter values were recorded at admission and at 24 h. Patients were grouped according to whether signs of hemorrhagic shock did (n = 22) or did not (n = 27) occur within the first 24 h from admission. Patients who developed hemorrhagic shock had significantly higher splenic and renal Doppler RI, higher Injury Severity Score, and lower standard base excess at admission. By multivariate logistic regression, splenic Doppler RI resulted to be a predictor of hemorrhagic shock development within the first 24 h from admission. Splenic Doppler RI may represent a clinically useful noninvasive method for early detection of occult hemorrhagic shock and persistent occult hypoperfusion after polytrauma in adult patients.

Traumatic stress and hepatocyte apoptosis

Trauma can cause stress in organisms and may promote cell apoptosis and lead to pathological damage. A variety of factors are involved in this process. The mechanisms responsible for traumatic stress-induced apoptosis are complex and controversial, especially in non-nervous organs. The liver plays a key role in metabolism and is one of the target organs of severe stress. Stress-induced hyperglycemia, calcium overload, oxidative stress, ischemia/reperfusion, inflammatory response, and immunosuppression caused by traumatic stress may lead to hepatocyte apoptosis. Thus, it is of great significance to explore the relationship between traumatic stress and hepatocyte apoptosis.

Effect of oxidative stress on hepatic stress injury following traumatic brain injury in rats

AIM: To explore the effect of oxidative stress (OS) on hepatic stress injury (HSI) secondary to traumatic brain injury (TBI).

METHODS: The animal model was established using an improved Allen's method. Forty healthy male Wistar rats had been divided randomly into five groups: control group and 6, 12, 24 and 48 h TBI posttraumatic groups. The serum levels of ALT and AST were measured using enzymic assay. The serum tumor necrosis factor-α (TNF-α) was detected using ABC-ELISA technique. The MDA values of liver tissue were measured with thiobarbituric acid method, and SOD of liver tissue was measured using chemiluminescence. And pathological changes of liver tissue were observed under light and electronic microscopy.

RESULTS: At early period of HSI, the serum levels of ALT, AST and TNF-α and the MOD values of liver tissue were markedly increased in all TBI groups, and the SOD values of liver tissue were significantly decreased compared with control group (252.92 ± 56.29 vs 41.17 ± 7.88; 283.12 ± 45.28 vs 45.22 ± 6.57; 1138.27 ± 212.02 vs 210.56 ± 28.22; 15.21 ± 0.36 vs 6.14 ± 0.25; 78.13 ± 3.12 vs 135.58 ± 5.58, P < 0.01 or 0.05). Liver tissue injuries at varied degrees were observed under light and electron microscopy in each TBI group.

CONCLUSION: Oxidative stress may be involved in the pathogenesis of HSI which occurs early secondary to traumatic brain injury.

Increased plasma and optic nerve levels of IL-6, TNF-alpha, and MIP-2 following induction of ischemic optic neuropathy in mice

PURPOSE

To investigate levels of proinflammatory cytokines in a mouse model of anterior ischemic optic neuropathy (rAION).

METHODS

AION was induced in C57/BL6 mice and levels of IL-6, TNF-alpha, and MIP-2 were measured in plasma by ELISA and in the optic nerves by RT-PCR at predetermined intervals.

RESULTS

Plasma: IL-6 levels were elevated immediately after rAION induction and decreased gradually thereafter. TNF-alpha showed an early peak on day 1 and again from day 21. MIP-2 levels were increased until day 7. Optic nerve: IL-6, TNF-alpha, and MIP-2 levels increased within a few hours and then decreased gradually. IL-6 had a second peak on day 3.

CONCLUSIONS

Proinflammatory cytokines may play a role in the pathogenesis of rAION.

Hypovolemic shock evaluated by sonographic measurement of the inferior vena cava during resuscitation in trauma patients

BACKGROUND

Inferior vena cava (IVC) diameter immediately after fluid resuscitation has not yet been investigated in trauma patients with shock on arrival.

METHODS

Between June 2004 and May 2005, 30 trauma patients with hemorrhagic shock were prospectively investigated. Using ultrasound, we measured maximum anterior-posterior diameter of the IVC just below the diaphragm in the hepatic segment, in the expiratory phase. This was performed on arrival and when systolic blood pressure had been raised to over 90 mm Hg by fluid resuscitation in the emergency room. Subjects were divided into two groups: a transient responder group (n = 17) in which shock recurred after leaving the emergency room and a responder group (n = 13) in which blood pressure remained stable.

RESULTS

There were no significant differences between the two groups regarding age or gender, or regarding vital signs or IVC diameter on arrival. Average injury severity score in the transient responder group was significantly greater than that in the responder group. After fluid resuscitation, no significant intergroup differences were observed regarding vital signs. However, IVC diameter was significantly smaller in the transient responder group than in the responder group (6.5 +/- 0.5 mm; mean +/- SE vs. 10.7 +/- 0.7 mm, p < 0.05).

CONCLUSION

In trauma patients, inadequate dilatation of the IVC by fluid resuscitation, might indicate insufficient circulating blood volume despite normalization of blood pressure. In this small study, IVC diameter appeared a better predictor of recurrence of shock than blood pressure, heart rate, or arterial base excess. A larger prospective study is called for to clearly establish the sensitivity and specificity of this method.

Alterations of intestinal mucosa structure and barrier function following traumatic brain injury in rats

AIM: Gastrointestinal dysfunction is a common complication in patients with traumatic brain injury (TBI). However, the effect of traumatic brain injury on intestinal mucosa has not been studied previously. The aim of the current study was to explore the alterations of intestinal mucosa morphology and barrier function, and to determine how rapidly the impairment of gut barrier function occurs and how long it persists following traumatic brain injury.

METHODS: Male Wistar rats were randomly divided into six groups (6 rats each group) including controls without brain injury and traumatic brain injury groups at hours 3, 12, 24, and 72, and on day 7. The intestinal mucosa structure was detected by histopathological examination and electron microscopy. Gut barrier dysfunction was evaluated by detecting serum endotoxin and intestinal permeability. The level of serum endotoxin and intestinal permeability was measured by using chromogenic limulus amebocyte lysate and lactulose/mannitol (L/M) ratio, respectively.

RESULTS: After traumatic brain injury, the histopathological alterations of gut mucosa occurred rapidly as early as 3 hours and progressed to a serious state, including shedding of epithelial cells, fracture of villi, focal ulcer, fusion of adjacent villi, dilation of central chyle duct, mucosal atrophy, and vascular dilation, congestion and edema in the villous interstitium and lamina propria. Apoptosis of epithelial cells, fracture and sparseness of microvilli, loss of tight junction between enterocytes, damage of mitochondria and endoplasm, were found by electron microscopy. The villous height, crypt depth and surface area in jejunum decreased progressively with the time of brain injury. As compared with that of control group (183.7 ± 41.8 EU/L), serum endotoxin level was significantly increased at 3, 12, and 24 hours following TBI (434.8 ± 54.9 EU/L, 324.2 ± 61.7 EU/L and 303.3 ± 60.2 EU/L, respectively), and peaked at 72 hours (560.5 ± 76.2 EU/L), then declined on day 7 (306.7 ± 62.4 EU/L, P < 0.01). Two peaks of serum endotoxin level were found at hours 3 and 72 following TBI. L/M ratio was also significantly higher in TBI groups than that in control group (control, 0.0172 ± 0.0009; 12 h, 0.0303 ± 0.0013; 24 h, 0.0354 ± 0.0025; 72 h, 0.0736 ± 0.0105; 7 d, 0.0588 ± 0.0083; P < 0.01).

CONCLUSION: Traumatic brain injury can induce significant damages of gut structure and impairment of barrier function which occur rapidly as early as 3 hours following brain injury and lasts for more than 7 days with marked mucosal atrophy.

Effect of prophylactic intracerebroventricular injection of methylprednisolone on nitrogen and catecholamine excretion in the urine after laparotomy in rats

BACKGROUND

This study was carried out to determine whether the prophylactic injection of glucocorticoid into the intracerebroventricular (i.c.v.) space reduced TNF-alpha and IL-1beta mRNA synthesis in the brain after laparotomy, resulting in a reduction of nitrogen excretion in the urine.

PATIENTS AND METHODS

Male SD rats (body wt., 225-250 g, n = 114) were catheterized into the i.c.v. space on day 0. On day 4, the rats were assigned to four groups: (1) Control, (2) laparotomy (Trauma), (3) intraperitoneal (i.p.) injection of methylprednisolone (MP) plus laparotomy (IPMP), and (4) i.c.v. injection of MP plus laparotomy (ICVMP). Either 3 or 24 h after surgery, the animals were sacrificed. TNF-alpha and IL-1beta mRNA levels in tissues, including the brain cortex and hypothalamus, were measured by RT-PCR. The amounts of nitrogen and catecholamine excretion in the 24-h urine were determined.

RESULTS

The i.p. injection of MP reduced TNF-alpha and IL-1beta mRNA levels in all the tissues 3 h after laparotomy compared with those of the Trauma group. The icv injection of MP prevented elevation of the TNF-alpha and IL-1beta mRNA levels in the brain (cortex, TNF-alpha, ICVMP 0.43 +/- 0.06, P < 0.05, vs Trauma; cortex, IL-1beta, ICVMP 0.25 +/- 0.09, P < 0.05, vs. Trauma; hypothalamus, TNF-alpha, ICVMP 0.31 +/- 0.04, P < 0.05, vs. Trauma; hypothalamus, IL-1beta, ICVMP 0.25 +/- 0.14, P < 0.05, vs. Trauma), but did not inhibit an increase in TNF-alpha and IL-1beta mRNA levels in the liver and skeletal muscle. Both nitrogen and catecholamine excretions in the urine were decreased by ip and by i.c.v. injection of MP compared to those of the Trauma group (nitrogen, ICVMP 559.3 +/- 52.0 mg/day, P < 0.05, vs. Trauma; catecholamine, ICVMP 13.8 +/- 1.8 microg/day, P < 0.05, vs. Trauma).

CONCLUSION

A reduction in TNF-alpha and IL-1beta mRNA synthesis in the brain due to prophylactic injection of MP into the icv space reduced the catabolic response after laparotomy.

Effect of tumor weight and tube feeding on TNF-alpha and IL-1beta mRNA expression in the brain of mice

BACKGROUND

Previous studies have shown that cytokine mRNA expression is elevated in the brains of anorectic, tumor-bearing rats. The objectives of the current study were as follows: (1) to determine whether a small tumor would result in up-regulation of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta mRNA expression in the brain and other tissues of tumor-bearing mice; and (2) to determine whether hyperalimentation by tube feeding would prevent up-regulation of cytokine mRNA expression in the brain and other tissues of tumor-bearing mice.

METHODS

Male C57BL/6 mice were divided into 4 groups: (1) control mice fed ad libitum (Control); (2) tumor-bearing mice fed ad libitum (TB); (3) control mice receiving tube feeding (CTF); and (4) tumor-bearing mice receiving tube feeding (TBTF).

RESULTS

TNF-alpha and IL-1beta mRNA expression was elevated in the brains of mice with a 1% body weight tumor, relative to the control and CTF groups, without any detectable changes in the other organs. On the other hand, TNF-alpha and IL-1beta mRNA expression was elevated in all organs of mice with an 8% body weight tumor, relative to the control and CTF groups. Tube feeding did not change TNF-alpha and IL-1beta mRNA expression in mice burdened with either a 1% or 8% body weight tumor.

CONCLUSIONS

Up-regulation of cytokine mRNA synthesis occurs earlier in the brain than in other organs, and hyperalimentation does not change cytokine mRNA expression in tumor-bearing mice.

Administration of opiate receptor antagonist inhibits mucosal atrophy of the gut in fasting rats

OBJECTIVE

The objective of this study was to determine whether the opiate mu receptor antagonist naloxone would prevent atrophy of the gut in 24-h-fasted rats.

METHODS

Male Sprague-Dawley rats (n = 76, body weight 200-225 g) were catheterized in the jugular vein on Day 0. The rats were fed standard rat chow for 4 days. On Day 4, the diet was changed to the standard liquid diet, and the rats were allowed free access to the liquid diet. On Day 7, the rats were randomized into five groups: (1) free fed, (2) free fed plus naloxone, (3) pair fed, (4) fasting, (5) free fed plus morphine, (6) fasting plus naloxone. Either naloxone (0.16 mg/kg/h) or morphine (0. 21 mg/kg/h) was continuously infused via venous catheter for 24 h. On Day 8, 24 h after fasting or free feeding, the animals were sacrificed.

RESULTS

Twenty-four hours of fasting caused atrophy of the jejunum and elevated morphine levels in the brain (free fed, 931. 3 +/- 122.3 fmol/g, vs fasting, 1419.0 +/- 150.0, P < 0.05). Morphine infusion reduced villus height, mucosal weight, and protein content in jejunum as compared with the free fed rats receiving saline. Administration of naloxone caused an increase in villus height (fasting, 587.0 +/- 25.8 microm, vs fasting plus naloxone, 670.0 +/- 17.4, P < 0.05), mucosal weight (fasting, 17.4 +/- 1.8 mg/cm, vs fasting plus naloxone, 22.6 +/- 1.9, P < 0.05), and protein content (fasting, 13.5 +/- 0.7 microg/cm, vs fasting plus naloxone, 16.7 +/- 0.6, P < 0.05) in jejunum.

CONCLUSION

Mucosal atrophy of the jejunum is caused by endogenous opioid in fasting rats.