Sepsis‐induced expansion of granulocytic myeloid‐derived suppressor cells promotes tumour growth through Toll‐like receptor 4

Severe sepsis remains a frequent and dreaded complication in cancer patients. Beyond the often fatal short‐term outcome, the long‐term sequelae of severe sepsis may also impact directly on the prognosis of the underlying malignancy in survivors. The immune system is involved in all stages of tumour development, in the detection of transforming and dying cells and in the prevention of tumour growth and dissemination. In fact, the profound and sustained immune defects induced by sepsis may constitute a privileged environment likely to favour tumour growth. We investigated the impact of sepsis on malignant tumour growth in a double‐hit animal model of polymicrobial peritonitis, followed by subcutaneous inoculation of MCA205 fibrosarcoma cells. As compared to their sham‐operated counterparts, post‐septic mice exhibited accelerated tumour growth. This was associated with intratumoural accumulation of CD11b⁺Ly6G^high polymorphonuclear cells (PMNs) that could be characterized as granulocytic myeloid‐derived suppressor cells (G‐MDSCs). Depletion of granulocytic cells in post‐septic mice inhibited the sepsis‐enhanced tumour growth. Toll‐like receptor (TLR)‐4 (Tlr4) and Myd88 deficiencies prevented sepsis‐induced expansion of G‐MDSCs and tumour growth. Our results demonstrate that the myelosuppressive environment induced by severe bacterial infections promotes malignant tumour growth, and highlight a critical role of CD11b⁺Ly6G^high G‐MDSCs under the control of TLR‐dependent signalling. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Characteristics of alveolar macrophages in experimental septic lung.

We investigated the pathogenesis of lung injury in sepsis (septic adult respiratory distress syndrome) by focusing on the functional changes of alveolar macrophages (AMs). Sepsis was induced in male WK rats by cecal ligation and puncture. Histological examination of the lungs from this experimental model revealed edematous change at 24 h after the surgery. The protein and endotoxin concentrations in the bronchoalveolar lavage fluid (BALF) increased with time after the surgery. The time course studies of AM function after surgery indicated that AMs from septic rats were activated by endotoxins. Specifically, this was suggested by the finding that AM adherence to and spreading on a plastic dish had increased. On stimulation, these AMs enhanced generation of superoxide anions and increased release of lysosomal enzymes, such as beta-glucuronidase. On the other hand, AMs in sepsis generated much smaller amounts of arachidonate lipoxygenase metabolites, such as leukotriene B4 (LTB4) and 12- and 5-hydroxyeicosatetraenoic acids (HETEs), on stimulation than did AMs from sham rats or untreated rats. However, the concentrations of immunoreactive LTC4 in the BALF of septic rats seemed to be higher than in untreated rats. It is suggested that the AMs of septic rats released lipoxygenase metabolites in alveoli and that these AMs could not be stimulated in vitro. These functional changes in the AMs of septic rats progressed along with the sepsis. These results implicate AMs in the development and progression of septic lung injury by releasing superoxide anions, beta-glucuronidase, and arachidonate metabolites. Furthermore, we speculate that reduced production of LTB4 by septic AMs may increase host susceptibility to severe pulmonary infection during septic ARDS.     

Changes in skeletal muscle size, fibre-type composition and capillary supply after chronic venous occlusion in rats

Aim: We have previously shown that surgical occlusion of some veins from skeletal muscle results in muscle hypertrophy without mechanical overloading in the rat. The present study investigated the changes in muscle‐fibre composition and capillary supply in hypertrophied muscles after venous occlusion in the rat hindlimb. Methods: Sixteen male Wistar rats were randomly assigned into two groups: (i) sham operated (sham‐operated group; n = 7); (ii) venous occluded for 2 weeks (2‐week‐occluded group; n = 9). At the end of the experimental period, specimens of the plantaris muscle were dissected from the hindlimbs and subjected to biochemical and histochemical analyses. Results: Two weeks after the occlusion, both the wet weight of plantaris muscle relative to body weight and absolute muscle weight showed significant increases in the 2‐week‐occluded group (～15%) when compared with those in the sham‐operated group. The concentrations of muscle glycogen and lactate were higher in the 2‐week‐occluded group, whereas staining intensity of muscle lipid droplets was lower in the 2‐week‐occluded group than those in the sham‐operated group. The percentage of type I muscle fibre decreased, whereas that of type IIb fibre increased in the 2‐week‐occluded group when compared with the sham‐operated group. Although the expression of vascular endothelial growth factor‐188 mRNA increased, the number of capillaries around the muscle fibres tended to decrease (P = 0.07). Conclusion: Chronic venous occlusion causes skeletal muscle hypertrophy with fibre‐type transition towards faster types and changes in contents of muscle metabolites.     

Bacteremia Does Not Affect Cellular Uptake of Ultrafine Particles in the Lungs of Rats

To assess the effects of intra‐abdominal bacteremia on lung cellular function in vivo, we used electron microscopy to quantify the uptake of 6 nm diameter, albumin‐coated colloidal gold particles (overall diam. 20.8 nm) by cells in the lungs of rats made septic by the introduction of live bacteria (E.coli and B. fragilis) into their abdomens. Gold particles were instilled into the trachea 24 hr after bacteremia induction, and lungs were harvested and prepared for electron microscopy 24 hr later. Because bacteremia produces an increase in metabolism, we hypothesized that this might be associated with increased cellular uptake of these particles and also with increased permeability of the alveolar epithelial barrier to them, as bacteremia is also associated with lung injury. We quantified particle uptake by counting particle densities (particles/μm²) within type I and type II epithelial cells, capillary endothelial cells, erythrocytes and neutrophils in the lungs of five septic rats and five sham‐sepsis controls. We also counted particle densities within organelles of these cells (nuclei, mitochondria, type II cell lamellar bodies) and within the alveolar interstitium. We found particles to be present within all of these compartments, although we found no differences in particle densities between bacteremic rats and sham‐sepsis controls. Our results suggest that these 6 nm particles were able to freely cross cell and organelle membranes, and further suggest that this ability was not altered by bacteremia. Anat Rec, 2011. © 2010 Wiley‐Liss, Inc.     

The effects of midazolam and ketamine on D-tubocurarine-induced twitch depression in septic rat diaphragm

The aim of this study was to elucidate the effects of midazolam and ketamine on neuromuscular blockade induced by non-depolarizing muscle relaxants (NDMRs) under the condition of sepsis induced by panperitonitis. A CLP operation (laparotomy, cecal ligation, and puncture of the cecum; septic group) or sham laparotomy (sham group) was performed on rats under O2-isoflurane anesthesia. At 18 hours after the operation, isometric twitch tensions of rat nerve-hemidiaphragm preparations elicited by indirect or direct stimulation at 0.1 Hz were measured. Midazolam enhanced the dTc (1 microM)-induced twitch depression (p < 0.05) at a high concentration (10 microM) in the septic group but not in the sham group. Ketamine enhanced the dTc (1 microM)-induced twitch depression in the sham group (p < 0.01) but not in the septic group. Midazolam and ketamine had no effect on directly elicited twitch tensions in either group. The results indicate that sepsis facilitates the midazolam-induced enhancement of the neuromuscular blocking effect of dTc but, conversely, inhibits the ketamine-induced enhancement. Sepsis elicits manifold alterations in the influence of intravenous anesthetics and sedatives on NDMR-induced neuromuscular blockade.     

Procalcitonin kinetics – prognostic and diagnostic significance in septic patients

Introduction

Severe sepsis and septic shock are advanced clinical conditions representing the patient''s response to infection and having a variable but high mortality rate. Early evaluation of sepsis stage and choice of adequate treatment are key factors for survival. Some study results suggest the necessity of daily procalcitonin (PCT) monitoring because of its prognostic and discriminative value.

Material and methods

An observational and prospective study was conducted to evaluate the prognostic and discriminative value of PCT kinetics in comparison to PCT absolute value measurements. In a group of 50 intensive care unit patients with diagnosis of severe sepsis or septic shock, serum PCT measurements were performed on admission, and on the 2^nd, 3^rd and 5^th day of therapy. The level of PCT was determined with a commercially available test according to the manufacturer''s protocol.

Results

The kinetics of PCT assessed by ΔPCT was statistically significant in the survivors vs. the non-survivors subgroup (ΔPCT_3/1, p = 0.022; ΔPCT_5/1, p = 0.021). ΔPCT has no statistical significance in the severe sepsis and septic shock subgroups for all analyzed days. Only the 5^th day PCT level was significantly higher in the non-survivors vs. survivors group (p = 0.008). The 1^st day PCT level in the severe sepsis vs. septic shock group has a discriminative impact (p = 0.009).

Conclusions

According to the results, single serum PCT measurement, regardless of absolute value, has a discriminative impact but no prognostic significance, during the first 2 days of therapy. The PCT kinetics is of prognostic value from the 3^rd day and is of earlier prognostic significance in comparison to changes in the patient''s clinical condition evaluated by SOFA score kinetics.     

Expression and characterization of anionic components in the tubulointerstitial compartment of rat kidney during polymicrobial sepsis

The aim of the study was to evaluate sialic acids and hyaluronan expression, anionic components important for the structure and function of the renal tubulointerstitial compartment, in the early stages of sepsis. Two groups of rats were used: (1) sham-operated controls; (2) cecal ligation and puncture (CLP) (polymicrobial sepsis model). A search for microbial growth was made in the peritoneal fluid to document infection. Tubular function was evaluated by means of urinary protein loss, urinary Na⁺ and urea excretion. Kidney samples were processed to analyze histology, sialic acids (lectin histochemistry) and hyaluronan (immunohistochemistry) expression. Results showed increased urinary protein loss and fractional excretion of Na⁺ and urea reduction in the CLP group. Histological changes, particularly in the cortex and in proximal tubules of the CLP group, were observed. In septic rats, compared to controls, sialic acids decreased in amount and their acetylation increased in the tubules, although to a lesser extent in the proximal portion. Hyaluronan was expressed in the medullary interstitium and in a few areas of cortex in controls. In septic rats it increased in the cortical interstitium and appeared in proximal tubules. These results suggest correlation between expression changes of anionic components and tubulointerstitium morphofunctional alterations during sepsis. A role of these molecules in protection/defense and repair processes may be suggested.     

Farnesyltransferase inhibitor FTI‐277 inhibits PD‐L1 expression on septic spleen lymphocytes and promotes spleen lymphocyte activation

Farnesyltransferase inhibitors have been tested in clinical trials for the treatment of tumours. In sepsis, the binding of programmed death 1 (PD‐1) to programmed death ligand 1 (PD‐L1) promotes lymphocyte apoptosis and decreases cytokine expression, thus affecting survival rates. The PD‐1/PD‐L1 pathway plays an important role in chronic viral infection, bacterial infection and sepsis. However, the precise immunosuppressive and anti‐inflammatory functions of this pathway remain poorly understood. In our previous study, the induction of sepsis by caecal ligation and puncture (CLP) resulted in increased farnesyltransferase activity and farnesylated protein levels in the spleen relative to sham treatment. However, the effect of inhibition of farnesyltransferase activity on overall survival rates in patients with sepsis and the specific signalling pathway involved remain to be investigated. In this study, mice with CLP‐induced sepsis were treated with farnesyltransferase inhibitor (FTI‐277), and PD‐L1 expression on septic spleen lymphocytes was examined. Flow cytometric analysis revealed that PD‐L1 is expressed constitutively on lymphocytes and that PD‐L1 protein expression was up‐regulated strongly following CLP. FTI‐277 down‐regulated PD‐L1 mRNA and protein expression on septic spleen lymphocytes in a dose‐dependent manner. This effect was associated closely with nuclear factor kappa B (NF‐κB). In addition, the significant damping effect of FTI‐277 on the PD‐L1 signal promoted interferon (IFN)‐γ secretion, interleukin (IL)‐2 production and splenocyte proliferation in response to anti‐CD3⁺CD28⁺ antibodies in mice. Furthermore, FTI‐277 reduced spleen lymphocyte apoptosis in septic mice. Therefore, FTI‐277 regulates spleen lymphocyte activity via the PD‐L1 signalling pathway, with significant anti‐inflammatory effects attributable to suppression of the NF‐κB pathway. Farnesyltransferase represents a valuable therapeutic target for the treatment of sepsis.     

电针百会、水沟穴上调脓毒性脑病大鼠脑红蛋白的表达

目的　观察并探讨大鼠出现脓毒性脑病时脑红蛋白（Neuroglobin,Ngb）的表达及电针百会、水沟穴对脓毒性脑病大鼠Ngb表达的影响。 方法　本研究采用经CLP造模成功的脓毒症大鼠通过观察大鼠神经行为学改变制作脓毒性脑病模型。将大鼠分为假手术组、脓毒性脑病组和脓毒性脑病+电针治疗组。取大鼠穴位百会、水沟穴分别沿皮刺入2 mm并接电极,另一电极夹在大鼠右耳尖端。疏密波,频率2 Hz/15 Hz,电流强度1 mA,以大鼠右耳微颤为电针刺激有效的标志,每 12 h治疗30 min。2个组分别持续24 h和72 h。通过对大鼠脑组织切片及冰上取材,在24 h和72 h行免疫组化检测Ngb 、Western blot检测Ngb蛋白表达水平及RealTime PCR检测Ngb mRNA基因表达水平,以测定电针百会、水沟穴对脓毒性脑病大鼠Ngb表达的影响。 结果　和假手术组比较,脓毒性脑病24 h组及72 h组的Ngb蛋白表达水平均明显上调（P<0.01）;电针干预脓毒性脑病24 h组和非电针干预24 h组比较,Ngb蛋白表达明显上调（P<0.01）;电针干预脓毒性脑病72 h组和非电针干预72 h组比较,Ngb蛋白表达稍有下调（P<0.01）。 结论　脓毒性脑病中Ngb表达上调,电针干预对脓毒性脑病有治疗作用,24 h最为明显,显示及时电针治疗脓毒性脑病效果明显,主要是通过上调Ngb表达起作用。     

Superoxide production of peritoneal macrophages in experimental gram-negative sepsis; influence of in vitro and in vivo supplements of zinc

Although zinc is essential for the optimum function of the immune system, there is some controversy regarding treatment with zinc during acute infections where low serum zinc levels are often recorded. The aim of the present study was to investigate the influence of in vitro and in vivo zinc supplementation on the potentially toxic metabolic activity of peritoneal macrophages during infection. Rats were made septic by implanting a gelatin capsule containing known amounts of E. coli, and Bacteroides fragilis into the abdomen. Peritoneal macrophages were harvested by peritoneal lavage 72 hours after the induction of sepsis. Superoxide release was measured after stimulation with phorbol myristate acetate (PMA) or serum treated zymosan (STZ). Macrophages from septic rats released significantly higher amounts of superoxide compared with macrophages from sham operated controls after stimulation with both PMA and STZ. Following in vitro supplementation, zinc inhibited the superoxide production of macrophages harvested from septic rats after stimulation with both PMA and STZ. In vivo supplementation with zinc resulted in increased superoxide production from septic macrophages when stimulated with STZ, whereas stimulation with PMA produced no significant changes. Thus, in vitro incubation inhibited the superoxide production of peritoneal macrophages in intraabdominal sepsis, whilst in vivo administration of zinc produced no such effect, and the effect seemed to vary depending on the stimuli used to initiate the respiratory burst.     

Sildenafil treatment attenuates lung and kidney injury due to overproduction of oxidant activity in a rat model of sepsis: a biochemical and histopathological study

Sepsis is a systemic inflammatory response to infection and a major cause of morbidity and mortality. Sildenafil (SLD) is a selective and potent inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase PDE5. We aimed to investigate the protective effects of sildenafil on caecal ligation and puncture (CLP)-induced sepsis in rats. Four groups of rats were used, each composed of 10 rats: (i) 10 mg/kg SLD-treated CLP group; (ii) 20 mg/kg SLD-treated CLP group; (iii) CLP group; and (iv) sham-operated control group. A CLP polymicrobial sepsis model was applied to the rats. All groups were killed 16 h later, and lung, kidney and blood samples were analysed histopathologically and biochemically. Sildenafil increased glutathione (GSH) and decreased the activation of myeloperoxidase (MPO) and of lipid peroxidase (LPO) and levels of superoxide dismutase (SOD) in the septic rats. We observed a significant decrease in LPO and MPO and a decrease in SOD activity in the sildenafil-treated CLP rats compared with the sham group. In addition, 20 mg/kg sildenafil treatment in the sham-operated rats improved the biochemical status of lungs and kidneys. Histopathological analysis revealed significant differences in inflammation scores between the sepsis group and the other groups, except the CLP + sildenafil 10 mg/kg group. The CLP + sildenafil 20 mg/kg group had the lowest inflammation score. Sildenafil treatment decreased the serum tumour necrosis factor (TNF)-α level when compared to the CLP group. Our results indicate that sildenafil is a highly protective agent in preventing lung and kidney damage caused by CLP-induced sepsis via maintenance of the oxidant-anti-oxidant status and decrease in the level of TNF-α.     

Increased Expression of Programmed Cell Death‐1 in Regulatory T Cells of Patients with Severe Sepsis and Septic Shock: An Observational Clinical Study

While regulatory T cells (Tregs) constitutively express programmed cell death‐1 (PD‐1), the role of PD‐1 expression in Tregs of patients with sepsis remains unclear. Thus, we determined PD‐1 expression in Tregs from the peripheral blood of patients with severe sepsis and septic shock. Seventy‐eight patients with severe sepsis and 40 with septic shock, as well as 21 healthy subjects, were enrolled in this study. The percentage of peripheral blood PD‐1⁺ Tregs, as well as absolute Treg counts, were compared between these three groups. PD‐1 expression in Tregs and absolute Treg counts were also compared between survivors and non‐survivors in patients with sepsis. PD‐1 expression in Tregs increased in patients with sepsis compared to healthy controls. Conversely, absolute Treg counts were significantly decreased in patients with sepsis compared to healthy controls; patients with septic shock had the lowest absolute Treg counts. Among patients with sepsis, survivors had lower levels of PD‐1 expression in Tregs, as well as higher absolute Treg counts, than non‐survivors. Additionally, the percentage of PD‐1⁺ Tregs correlated positively with lactate levels as well as the Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores in patients with sepsis. PD‐1 was upregulated in Tregs of patients with sepsis and may indicate a state of immune dysfunction. Overexpression of PD‐1 in Tregs was associated with more severe sepsis as well as poor outcomes.     

Inflammasome gene profile is modulated in septic patients,with a greater magnitude in non‐survivors

Inflammasome signalling induces the processing and secretion of interleukin (IL)‐1β and IL‐18 which, coupled with pyroptosis, activate further the inflammatory response. In the present study we evaluated the expression of genes involved in inflammasome signalling pathways in septic patients, their interaction networks and the predicted functions modulated in survivors and non‐survivors. Twenty‐seven patients with sepsis secondary to community‐acquired pneumonia admitted to intensive care units from three general hospitals in São Paulo were included into the study. We performed a polymerase chain reaction (PCR) array encompassing 35 genes related to the nucleotide‐binding oligomerization domain and leucine‐rich repeat‐containing (NLR)‐inflammasome in peripheral blood mononuclear cells obtained at admission and after 7 days of follow‐up. Eleven healthy volunteers were used as the reference group. Increased NLRC4 and NLRP3 and decreased nucleotide‐binding oligomerization domain (NOD1), and NLRP1 expression was observed in septic patients compared to healthy individuals; the IL‐1β and IL‐18 expression levels were also high in the patients. The gene expression changes followed the same patterns in surviving and non‐surviving patients, with higher magnitudes observed in non‐survivors. Functional analyses revealed, however, that activation and inhibition intensity for representing functions were different in survivors and non‐survivors, as for production of reactive oxygen species, synthesis of nitric oxide and for the control of bacterial infections. Our results showed that the genes involved in the activation of the NLR‐inflammasome cascades were altered substantially in septic patients, with a higher number of altered genes and a higher intensity in the disturbance of gene expression found among patients dying of sepsis.     

Evaluation of serum C-reactive protein, procalcitonin, tumor necrosis factor alpha, and interleukin-10 levels as diagnostic and prognostic parameters in patients with community-acquired sepsis, severe sepsis, and septic shock

The diagnostic value of procalcitonin, C-reactive protein, tumor necrosis factor-alpha, and interleukin-10 levels in differentiating sepsis from severe sepsis and the prognostic value of these levels in predicting outcome were evaluated and compared in patients with community-acquired sepsis, severe sepsis, and septic shock in the first 72 h of admission to the hospital. Thirty-nine patients were included in the study. The severe sepsis and septic shock cases were combined in a single “severe sepsis” group, and all comparisons were made between the sepsis (n=21 patients) and the severe sepsis (n=18 patients) groups. Procalcitonin levels in the severe sepsis group were found to be significantly higher at all times of measurements within the first 72 h and were significantly higher at the 72nd hour in patients who died. Procalcitonin levels that remain elevated at the 72nd hour indicated a poor prognosis. C-reactive protein levels were not significantly different between the groups, nor were they indicative of prognosis. No significant differences in the levels of tumor necrosis factor-alpha were found between the sepsis and severe sepsis groups; however, levels were higher at the early stages (at admission and the 24th hour) in patients who died. Interleukin-10 levels were also higher in the severe sepsis group and significantly higher at all times of measurement in patients who died. When the diagnostic and prognostic values at admission were evaluated, procalcitonin and interleukin-10 levels were useful in discriminating between sepsis and severe sepsis, whereas tumor necrosis factor-alpha and interleukin-10 levels were useful in predicting which cases were likely to have a fatal outcome.     

Ozone therapy and hyperbaric oxygen treatment in lung injury in septic rats

Various therapeutic protocols were used for the management of sepsis including hyperbaric oxygen (HBO) therapy. It has been shown that ozone therapy (OT) reduced inflammation in several entities and exhibits some similarity with HBO in regard to mechanisms of action. We designed a study to evaluate the efficacy of OT in an experimental rat model of sepsis to compare with HBO. Male Wistar rats were divided into sham, sepsis+cefepime, sepsis+cefepime+HBO, and sepsis+cefepime+OT groups. Sepsis was induced by an intraperitoneal injection of Escherichia coli; HBO was administered twice daily; OT was set as intraperitoneal injections once a day. The treatments were continued for 5 days after the induction of sepsis. At the end of experiment, the lung tissues and blood samples were harvested for biochemical and histological analysis. Myeloperoxidase activities and oxidative stress parameters, and serum proinflammatory cytokine levels, IL-1β and TNF-α, were found to be ameliorated by the adjuvant use of HBO and OT in the lung tissue when compared with the antibiotherapy only group. Histologic evaluation of the lung tissue samples confirmed the biochemical outcome. Our data presented that both HBO and OT reduced inflammation and injury in the septic rats' lungs; a greater benefit was obtained for OT. The current study demonstrated that the administration of OT as well as HBO as adjuvant therapy may support antibiotherapy in protecting the lung against septic injury. HBO and OT reduced tissue oxidative stress, regulated the systemic inflammatory response, and abated cellular infiltration to the lung demonstrated by findings of MPO activity and histopathologic examination. These findings indicated that OT tended to be more effective than HBO, in particular regarding serum IL-1β, lung GSH-Px and histologic outcome.     

Ghrelin对脓毒症肺损伤大鼠肺泡巨噬细胞及肺组织iNOS表达的影响

 目的： 观察ghrelin对脓毒症肺损伤大鼠肺泡巨噬细胞及肺组织诱导型一氧化氮合酶（inducible nitric oxide synthase, iNOS）表达的影响。方法： SD雄性大鼠分为假手术组、脓毒症组及ghrelin治疗组,前2组各设术后6 h、12 h和20 h亚组。通过盲肠结扎穿孔术（cecal ligation and puncture, CLP）建立脓毒症模型,ghrelin治疗组于术后3 h及15 h腹腔注射ghrelin,术后20 h取材。各组按术后既定时间行支气管肺泡灌洗收集肺泡巨噬细胞,RT-PCR检测肺泡巨噬细胞中iNOS mRNA的表达水平。另一部分大鼠则在术后20 h采集右肺,行肺病理学检查及Western blotting检测肺组织iNOS蛋白表达。结果： 脓毒症组在CLP术后6 h、12 h和20 h肺泡巨噬细胞iNOS mRNA的表达水平分别为1.33±0.05、1.44±0.08和1.57±0.11,均高于假手术组（P＜0.05）,并不随时间延长而升高;但在术后20 h却低于ghrelin治疗组（2.27±0.37;P＜0.05）。Ghrelin治疗组CLP术后20 h肺组织iNOS蛋白表达水平（0.87± 0.03）低于脓毒症组（P＜0.05）。Ghrelin治疗组肺组织病理学评分（5.83±0.477）较脓毒症组（7.83±0.75）低,2组均高于假手术组（P＜0.05）。结论： CLP术后6～20 h,大鼠肺泡巨噬细胞iNOS mRNA的表达水平升高,但无时间依赖性。Ghrelin对脓毒症大鼠肺泡巨噬细胞iNOS mRNA表达起上调作用,而对肺组织iNOS蛋白表达起抑制作用,减轻肺损伤程度。     

Ghrelin clearance is reduced at the late stage of polymicrobial sepsis

The cardiovascular response to sepsis is characterized by an early, hyperdynamic phase followed by a late, hypodynamic phase. Ghrelin, a newly-identified endogenous ligand for growth hormone secretagogue receptor (i.e., ghrelin receptor), was recently demonstrated to be a potent vasoactive peptide in addition to its effects on growth hormone release and energy homeostasis. We have shown that ghrelin (via its receptor) may play an important role in regulating cardiovascular responses in the progression of polymicrobial sepsis. However, it remains unknown whether the clearance of this peptide is altered in sepsis. To determine this, male adult rats were injected with 125I-ghrelin through the jugular vein at 5 or 20 h after cecal ligation and puncture (CLP, i.e., sepsis model) or sham operation. The blood sample was collected every 2 min for 30 min for determining half-life (t1/2). Tissue samples (i.e., kidneys, liver, brain, heart, lungs, spleen, stomach, small intestine, large intestine, skin and muscle) were then harvested. The radioactivities of samples were counted. The results indicate that 125I-ghrelin's t1/2 and its distribution were not significantly altered in early sepsis (5 h after CLP). However, the t1/2 increased significantly in late sepsis (20 h after CLP). Tissue distribution of 125I-ghrelin was far greater in the kidneys than in any other tissues tested in both sham and septic animals. Moreover, the kidneys and liver had significantly less radioactive uptake at 20 h after CLP, but the radioactivity in blood was much higher at the same time point. There were no significant changes in 125I-ghrelin distribution in other organs at the late stage of sepsis. These results indicate that the kidneys are the primary site of ghrelin clearance, which is significantly diminished in late sepsis. In addition, the liver also plays a role in the clearance of ghrelin, which was also reduced in late sepsis. The decreased clearance of ghrelin by the kidneys and liver may be due to renal and hepatic dysfunctions under such conditions.     

Degeneration of the seminiferous epithelium following epididymal obstruction in prepubertal rats

The development of the testes was studied in rats following prepubertal obstruction of the epididymis. Male rats received bilateral ligation of the corpus epididymidis or a sham operation at 10 days of age, and temporal changes in testicular morphology and weights of reproductive organs were determined at intervals spanning sexual maturation. Development of the testes was normal through 35 days of age. The initial histological changes in the testes of ligated animals, observed at 56 days, included an increased diameter of the seminiferous tubule lumen, depletion of spermatids, and the presence of multinucleate spermatids. Subsequently, germ cells were greatly depleted in the testes of 91‐ and 128‐day‐old rats with ligated epididymides. After puberty, testicular weight and volume declined relative to corresponding sham‐operated animals. On the other hand, the weights of the epididymides in ligated animals prior to puberty significantly exceeded those of sham‐operated rats but weighed significantly less than those of rats in the sham group after sexual maturation. Testicular alterations occurred after increases in the weights of the epididymides. Testicular changes may have contributed to rather than resulted from an autoimmune response to spermatozoa because testicular alterations preceded increases in antisperm autoantibodies. Anat Rec 254:76–86, 1999. © 1999 Wiley‐Liss, Inc.     

Changes in the metabolic profile of rat liver after α-tocopherol deficiency as revealed by metabolomics analysis

Metabolomics is an approach in which the profiles of metabolites in different tissues and/or biofluids are investigated to understand the changes induced following a modulation. We used this approach to investigate the biochemical effects of α‐tocopherol in the liver using a rat model. Rats (21‐day‐old) were fed either an α‐tocopherol‐sufficient control (n = 10) or an α‐tocopherol‐deficient (n = 10) diet for 2 months before sacrifice. Livers were homogenized in methanol–chloroform–water (3 : 1 : 1, v/v/v), and the polar phase extracts of the liver samples were analyzed using ¹H NMR. Multivariate statistical analysis of the data was performed using principal component analysis and orthogonal partial least squares‐discriminant analysis. Identification of ¹H NMR signals was performed primarily using the Human Metabolome Database, Biological Magnetic Resonance Data Bank and previous literature, and confirmed by spiking with metabolites and applying two‐dimensional NMR. The statistical analysis revealed that α‐tocopherol deficiency caused an increase in carnitine, choline, L ‐valine, L ‐lysine, tyrosine and inosine content and a reduction in glucose and uridine 5′‐monophosphate content. Changes in carnitine and glucose suggest a possible shift in energy metabolism. Copyright © 2010 John Wiley & Sons, Ltd.     

Plasma PTX3, MCP1 and Ang2 are early biomarkers to evaluate the severity of sepsis and septic shock

Sepsis is associated with significant mortality. Early diagnosis and prognosis of patients with sepsis is still a difficult clinical challenge. In this study, the ability of plasma PTX3 (pentraxin 3), MCP1 (monocyte chemoattractant protein 1) and Ang (angiopoietin)1/2 was investigated to evaluate the severity of sepsis. Blood samples were obtained from 43 patients with sepsis. A total of 33 post‐surgery patients with infections and 25 healthy individuals served as controls. The results showed that plasma PTX3, MCP1 and Ang2 significantly increased in patients on the first day of septic shock onset, while sepsis patients had significantly higher Ang2 level, compared with controls. Furthermore, PTX3, MCP1 and Ang2 had high AUROC values in patients with septic shock on the first day of sepsis onset. The findings suggest that PTX3, MCP1 and Ang2 maybe early predictors to evaluate the severity of sepsis and septic shock with the latest Sepsis 3.0 definitions.