Free radical scavenging by lazaroids improves renal blood flow during sepsis

Pentoxifylline for treatment of sepsis and necrotising enterocolitis in neonates

BACKGROUND

Mortality and morbidity due to neonatal sepsis and necrotising enterocolitis (NEC) remain high despite the use of potent antimicrobial agents. Agents that modulate inflammation may improve outcomes. Pentoxifylline (PTX), a phosphodiesterase inhibitor, is one such agent. This is an update of a review first published in 2003 and updated in 2011 and 2015.

OBJECTIVES

To assess the effectiveness and safety of intravenous PTX as an adjunct to antibiotic therapy on mortality and morbidity in neonates with suspected or confirmed sepsis and neonates with NEC.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, and trial registries in July 2022. We also searched the reference lists of identified clinical trials and handsearched conference abstracts.   SELECTION CRITERIA: We included randomised controlled trials (RCTs) or quasi-RCTs assessing the efficacy of PTX with antibiotics (any dose or duration) for treatment of suspected or confirmed sepsis or NEC in neonates. We included three comparisons: (1) PTX with antibiotics compared to placebo or no intervention with antibiotics; (2) PTX with antibiotics compared to PTX with antibiotics and adjunct treatments such as immunoglobulin M-enriched intravenous immunoglobulin (IgM-enriched IVIG); (3) PTX with antibiotics compared to adjunct treatments such as IgM-enriched IVIG with antibiotics.

DATA COLLECTION AND ANALYSIS

We reported typical risk ratio (RR) and risk difference (RD) with 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) for continuous outcomes derived from a fixed-effect model of meta-analysis. We calculated the number needed to treat for an additional beneficial outcome (NNTB) if there was a statistically significant reduction in RD.

MAIN RESULTS

We identified no new studies for this update. We included six RCTs (416 neonates). All of the included studies examined neonates with sepsis; we identified no studies on neonates with NEC. Four of the six trials had high risk of bias for at least one risk of bias domain. Comparison 1: PTX with antibiotics compared to placebo with antibiotics, or antibiotics alone, in neonates with sepsis may reduce all-cause mortality during hospital stay (typical RR 0.57, 95% CI 0.35 to 0.93; typical RD -0.08, 95% CI -0.14 to -0.01; NNTB 13, 95% CI 7 to 100; 6 studies, 416 participants, low-certainty evidence) and may decrease length of hospital stay (LOS) (MD -7.74, 95% CI -11.72 to -3.76; 2 studies, 157 participants, low-certainty evidence). The evidence is very uncertain that PTX with antibiotics compared to placebo or no intervention results in any change in chronic lung disease (CLD) (RR 1.50, 95% CI 0.45 to 5.05; 1 study, 120 participants, very low-certainty evidence), severe intraventricular haemorrhage (sIVH) (RR 0.75, 95% CI 0.28 to 2.03; 1 study, 120 participants, very low-certainty evidence), periventricular leukomalacia (PVL) (RR 0.50, 95% CI 0.10 to 2.63; 1 study, 120 participants, very low-certainty evidence), NEC (RR 0.56, 95% CI 0.29 to 1.06; 6 studies, 405 participants, very low-certainty evidence), or retinopathy of prematurity (ROP) (RR 0.40, 95% CI 0.08 to 1.98; 1 study, 120 participants, very low-certainty evidence) in neonates with sepsis. Comparison 2: the evidence is very uncertain that PTX with antibiotics compared to PTX with antibiotics and IgM-enriched IVIG has any effect on mortality (RR 0.71, 95% CI 0.24 to 2.10; 102 participants, 1 study, very low-certainty evidence) or development of NEC in neonates with sepsis (RR 1.33, 95% CI 0.31 to 5.66; 1 study, 102 participants, very low-certainty evidence). The outcomes of CLD, sIVH, PVL, LOS, and ROP were not reported. Comparison 3: the evidence is very uncertain that PTX with antibiotics compared to IgM-enriched IVIG with antibiotics has any effect on mortality (RR 1.25, 95% CI 0.36 to 4.39; 102 participants, 1 study, very low-certainty evidence) or development of NEC (RR 1.33, 95% CI 0.31 to 5.66; 102 participants, 1 study, very low-certainty evidence) in neonates with sepsis. The outcomes of CLD, sIVH, PVL, LOS, and ROP were not reported. All of the included studies evaluated adverse effects due to PTX, but none were reported in the intervention group in any of the comparisons.

AUTHORS' CONCLUSIONS

Low-certainty evidence suggests that adjunct PTX therapy in neonatal sepsis may decrease mortality and length of hospital stay without any adverse effects. The evidence is very uncertain if PTX with antibiotics compared to PTX with antibiotics and IgM-enriched IVIG, or PTX with antibiotics compared to IgM-enriched IVIG with antibiotics, has any effect on mortality or development of NEC. We encourage researchers to undertake well-designed multicentre trials to confirm or refute the effectiveness and safety of pentoxifylline in reducing mortality and morbidity in neonates with sepsis or NEC.

A Review on The Protective Effects of Metformin in Sepsis-Induced Organ Failure

Despite advances in sepsis management, it remains a major intensive-care-unit (ICU) concern. From new prospective, positive effects of metformin, such as anti-oxidant and anti-inflammatory properties are considered potentially beneficial properties for management of septic patients. This article reviewed the potential ameliorative effects of metformin in sepsis-induced organ failure. Information were retrieved from PubMed, Scopus, Embase, and Google Scholar. Multi-organ damage, oxidative stress, inflammatory cytokine stimulation, and altered circulation are hallmarks of sepsis. Metformin exerts its effect via adenosine monophosphate-activated protein kinase (AMPK) activation. It improves sepsis-induced organ failure by inhibiting the production of reactive oxygen species (ROS) and pro-inflammatory cytokines, preventing the activation of transcription factors related to inflammation, decreasing neutrophil accumulation/infiltration, and also maintaining mitochondrial membrane potential. Studies reported the safety of metformin therapeutic doses, with no evidence of lactic acidosis, in septic patients.

Bone mesenchymal stem cells ameliorate ischemia/reperfusion-induced damage in renal epithelial cells via microRNA-223

Background

Recent studies have indicated that microRNA-223 (miR-223) plays a role in the tissue-protective effect of mesenchymal stem cells (MSCs). NLR family-pyrin domain containing 3 (NLRP3) was reported to affect a renal ischemia/reperfusion (I/R) injury by exerting a direct effect on the renal tubular epithelium. Therefore, we investigated how miR-223 and NLRP3 might function in kidneys exposed to conditions of ischemia and subsequent reperfusion.

Methods

Hypoxia/reoxygenation (H/R) murine renal tubular epithelial cells (RTECs) were cocultured with either MSCs or hypoxia-pretreated MSCs (htMSCs), after which the RTECs were examined for their viability and evidence of apoptosis. Next, miR-223 expression in the MSCs was downregulated to verify that MSCs protected RTECs via the transport of miR-223. Kidney I/R KM/NIH mouse models were created and used for in vivo studies.

Results

The results showed that coculture with MSCs significantly increased the viability of RTECs and decreased their rates of apoptosis. The levels of hepatocyte growth factor (HGF), insulin-like growth factor-1 (IGF-1), transforming growth factor beta (TGF-β), and vascular endothelial growth factor (VEGF) in samples of coculture supernatants were higher than those in samples of non-coculture supernatants. A bioinformatics analysis revealed a targeting relationship between miR-223 and NLRP3. A dual luciferase assay showed that miR-223 inhibited NLRP3 expression. The htMSCs displayed a protective function associated with an upregulation of miR-223 as induced by Notch1 and the downregulation of NLRP3. Conversely, inhibition of miR-223 impeded the protective effect of MSCs. In the I/R mouse models, injection of either MSCs or htMSCs ameliorated the damage to kidney tissue, while suppression of miR-223 expression in MSCs reduced their protective effect on mouse kidneys.

Conclusions

Our results demonstrate that miR-223 and NLRP3 play important roles in the treatment of renal tissue injuries with transplanted MSCs.

Pentoxifylline for treatment of sepsis and necrotizing enterocolitis in neonates

BACKGROUND

Mortality and morbidity due to neonatal sepsis and necrotizing enterocolitis (NEC) remain high despite the use of potent antimicrobial agents. Agents that modulate inflammation may improve outcomes. Pentoxifylline, a phosphodiesterase inhibitor, is one such agent.

OBJECTIVES

Our primary objectives were :1.To assess the effect of intravenous pentoxifylline as an adjunct to antibiotic therapy on mortality and morbidity in neonates with suspected or confirmed sepsis.2.To assess the effect of intravenous pentoxifylline as an adjunct to antibiotic therapy on mortality and morbidity in neonates with NEC.

SEARCH METHODS

We searched the Cochrane Neonatal Review Group Specialized Register, CENTRAL (The Cochrane Library Issue 2, 2014), EMBASE (January 1980 to May 2014), PubMed (January 1966 to May 2014), CINAHL (January 1982 to May 2014), Science Citation Index (January 1990 to May 2014), and BIOSIS (January 1992 May 2014) in May 2014. We checked references and cross-references from identified studies. We handsearched abstracts from the proceedings of the Pediatric Academic Societies Meetings (from January 1990 to May 2014). We placed no restrictions on language.

SELECTION CRITERIA

We included randomised or quasi-randomised trials assessing the efficacy of pentoxifylline as an adjunct to antibiotics for treatment of suspected or confirmed sepsis or NEC in neonates.

DATA COLLECTION AND ANALYSIS

We reported typical risk ratio (RR) and risk difference (RD) with 95% confidence intervals (CI) using fixed-effect model for dichotomous outcomes and mean difference (MD) for continuous outcomes. We calculated the number needed to treat for an additional beneficial outcome (NNTB) if there was a statistically significant reduction in RD.

MAIN RESULTS

Pentoxifylline used as an adjunct to antibiotics in neonates with sepsis decreased all-cause mortality during hospital stay (typical RR 0.57, 95% CI 0.35 to 0.93; typical RD -0.08, 95% CI -0.14 to -0.01; NNTB 13, 95% CI 7 to 100; 6 studies, 416 participants, low-quality evidence). Subgroup analyses revealed decrease in mortality in preterm infants, infants with confirmed sepsis, and infants with gram-negative sepsis (low-quality evidence, four studies). Pentoxifylline decreased length of hospital stay (MD -7.59 days, 95% CI -11.65 to -3.52; 2 studies, 148 participants, low-quality evidence). Pentoxifylline did not change the risk of development of NEC, chronic lung disease, severe intraventricular haemorrhage, retinopathy of prematurity, or periventricular leukomalacia in neonates with sepsis (one to two studies, very low-quality evidence). Pentoxifylline therapy compared to pentoxifylline and immunoglobulin M-enriched intravenous immunoglobulin or immunoglobulin M-enriched intravenous immunoglobulin alone did not change mortality or development of NEC in neonates with sepsis (one study, very low-quality evidence). We noted no adverse effects due to pentoxifylline. We identified no trials evaluating pentoxifylline treatment for NEC.

AUTHORS' CONCLUSIONS

Low-quality evidence from six small studies suggests that pentoxifylline therapy as an adjunct to antibiotics in neonatal sepsis decreases mortality without any adverse effects. We encourage researchers to undertake large, well-designed multicentre trials to confirm or refute the effectiveness of pentoxifylline in reducing mortality and morbidity in neonates with sepsis or NEC.

The effects of montelukast on random pattern skin flap survival: An experimental study in rats

BACKGROUND

A variety of methods to improve skin flap survival, including the use of pharmacologic agents, have been intensively investigated. Decreasing neutrophil-mediated inflammation and tissue injury has been reported to be effective in improving flap survival. Montelukast is a selective reversible cysteinyl leukotriene receptor-1 antagonist that has been found to have protective effects against renal ischemia reperfusion injury and burn-induced oxidative injury of the skin in rats. However, its effects on skin flap survival have not been previously reported.

OBJECTIVE

The aim of this study was to investigate the effects of montelukast on neutrophil-mediated random pattern skin flap survival.

METHODS

Male Sprague-Dawley rats weighing 230 to 250 g were randomly divided into 2 groups-the montelukast-treated group and the control group. Caudally based rectangular random pattern skin flaps 3 × 9 cm were elevated on the backs of the rats. The flaps were sutured into their original places. In the montelukast group, 1 mL of solution containing 10 mg/kg montelukast was administered intraperitoneally (IP) 30 minutes before surgery and then daily for 6 days. In the control group, 1 mL of saline was administered IP 30 minutes before surgery and then daily for 6 days. To observe the effects of montelukast, myeloperoxidase (MPO) activity, an index of tissue neutrophil infiltration, was measured from extracted skin tissue 12 hours after flap elevation. Flap viability was evaluated 7 days after surgery by measuring necrotic flap area and total flap area.

RESULTS

Sixteen rats (mean [SD] weight, 240.6 [6.6] g) were equally divided between the 2 groups. All rats survived throughout the study period. Mean (SD) MPO activity in flap tissue was significantly lower in the montelukast group than in the control group (14.57 [2.33] vs 21.28 [4.86] U/g protein; P = 0.005). The percentage of necrotic flap area was significantly lower in the montelukast group than in the control group (17.17 [7.95] vs 37.51 [10.72]; P = 0.001).

CONCLUSION

This small, experimental, in vivo animal study found that montelukast was associated with both lower MPO activity and a lower percentage of necrotic random pattern skin flap area. Future studies are needed to clarify these findings.

Pentoxifylline for treatment of sepsis and necrotizing enterocolitis in neonates

BACKGROUND

Mortality and morbidity due to neonatal sepsis and necrotizing enterocolitis (NEC) is high despite the use of potent antimicrobial agents. Agents that modulate inflammation may improve outcomes. Pentoxifylline, a phosphodiesterase inhibitor, is one such agent.

OBJECTIVES

The primary objectives were to assess the effect on mortality and the safety of intravenous pentoxifylline as an adjunct to antibiotic therapy in neonates with suspected or confirmed sepsis and NEC.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2011), MEDLINE, EMBASE and CINAHL, Science Citation Index for articles referencing Lauterbach 1996, proceedings of the Pediatric Academic Societies (1990 to 2011), BIOSIS (1992 to 2011), conference proceedings (1992 to 2011), ongoing trials and reference lists of identified RCTs were searched in July 2011.

SELECTION CRITERIA

Randomised or quasi-randomised trials assessing the efficacy of pentoxifylline as an adjunct to antibiotics for treatment of suspected or confirmed sepsis or NEC in neonates were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted information for the outcomes of interest. Typical relative risk (RR) and risk difference (RD) with 95% confidence intervals (CI) using fixed effects model are reported for dichotomous outcomes and mean differences for continuous outcomes. NNT was calculated for outcomes for which there was a statistically significant reduction in RD.

MAIN RESULTS

In four randomised controlled trials, 227 neonates with suspected or confirmed sepsis were randomised to pentoxifylline or placebo. Pentoxifylline therapy significantly decreased "all cause mortality during hospital stay" in the overall population of infants with sepsis [typical RR 0.40 (95%CI 0.20 to 0.77); typical RD -0.15 (95%CI -0.26 to -0.05); NNT 7 (95%CI 4 to 20)]. Subgroup analyses revealed significant reduction in mortality in preterm infants, infants with confirmed sepsis and gram-negative sepsis. Pentoxifylline treatment significantly decreased length of hospital stay [mean difference -11.20 [95%CI -22.09 to -0.31] but not development of NEC in neonates with sepsis [typical RR 0.29 (95%CI 0.07 to 1.24); typical RD -0.20 (95%CI -0.41 to 0.01)]. No adverse effects due to pentoxifylline were noted. No completed trial of treatment with pentoxifylline for treatment of NEC was identified.

AUTHORS' CONCLUSIONS

Current evidence from four small studies suggests that the use of pentoxifylline as an adjunct to antibiotics in neonatal sepsis decreases mortality without any adverse effects. Researchers are encouraged to undertake large well-designed multicenter trials to confirm or refute the effectiveness of pentoxifylline in reducing mortality and adverse outcomes in neonates with suspected or confirmed neonatal sepsis and NEC.

Wen-pi-tang-Hab-Wu-ling-san attenuates kidney ischemia/reperfusion injury in mice. A role for antioxidant enzymes and heat-shock proteins

The purpose of this study was to investigate the effects of Wen-pi-tang-Hab-Wu-ling-san (WHW) extract, which has been used for treatment of renal diseases, on kidney ischemia/reperfusion (I/R) injury. Thirty minutes of bilateral renal ischemia resulted in disruption of kidney tubular epithelial cells and increased plasma creatinine levels in mice, however these effects were significantly attenuated when WHW was administered prior to I/R. WHW-administration also inhibited post-ischemic decreases of catalase, copper-zinc superoxide dismutase (CuZnSOD), and manganese superoxide dismutase (MnSOD) activity in kidney tissue, leading to decreased tissue hydrogen peroxide levels and lipid peroxidation. Post-ischemic increases of heat-shock protein (HSP)-27 and -72 expressions were greater in mouse kidneys that received WHW. In conclusion, WHW-administration reduced kidney susceptibility to I/R injury, and this reduced susceptibility was associated with greater post-ischemic activation of catalase, CuZnSOD and MnSOD, resulting in reduced hydrogen peroxide levels and lipid peroxidation, as well as higher post-ischemic expression of HSP-27 and -72.

Effects of Lazaroid U-74389G on Acute Necrotizing Pancreatitis in Rats

The aim of this study was to investigate the influence of U-74389G on acute necrotizing pancreatitis (ANP) induced by glycodeoxycholic acid in rats. The induction of ANP resulted in a significant increase in mortality rate, pancreatic necrosis, and serum levels of amylase, alanine aminotransferase, interleukin-6, tumor necrosis factor alpha, and urea, in lactate dehydrogenase levels in bronchoalveolar lavage fluid, and in the activities of myeloperoxidase and malondialdehyde in pancreas and lung tissue; a significant decrease was observed in serum calcium levels, blood pressure, urine output, and pO(2). The use of U-74389G inhibited the changes in serum urea, pO(2), and tissue levels of myeloperoxidase and malondialdehyde in pancreas and lungs. Moreover, it indicated a limited effect on the course of ANP in the rats and did not reduce mortality and pancreatic damage. Therefore, it may be used in the treatment of lung injury during acute pancreatitis.

The Effect of Hyperbaric Oxygen Treatment on the Renal Functions in Septic Rats: Relation to Oxidative Damage

PURPOSE

To investigate the effects of hyperbaric oxygen (HBO) treatment on renal functions and damage in septic rats.

METHODS

The animals were divided into four groups, each containing ten animals: control, hyperbaric oxygen, sepsis, and sepsis/hyperbaric oxygen. One milliliter of saline containing live Escherichia coli cells (2.1 x 10(9)) was injected intraperitoneally to induce sepsis. The groups treated with HBO were given five sessions of 2 atmospheres absolute of 100% oxygen at intervals of 6 h. Blood, urine, and tissue samples were then collected, and the functional renal parameters, malondialdehyde (MDA) levels, and superoxide dismutase (SOD) and catalase activities were examined.

RESULTS

The reduced glomerular filtration rate and urine flow returned to normal levels after HBO treatment; however, the increase in fractionated sodium excretion continued. The increased MDA levels in the renal cortex and medulla also decreased to the level of the control group. In the sepsis group, both the SOD and catalase activities decreased in the renal cortex, while a reduction was observed only in the catalase activity in the medulla. The reduced enzyme activities significantly increased in the sepsis/hyperbaric oxygen group.

CONCLUSION

HBO treatment has a beneficial effect on renal dysfunction in sepsis. The probable reason for this effect is the reduction in oxidative damage because of the increase in antioxidative capacity.

Renal blood flow in sepsis

Introduction

To assess changes in renal blood flow (RBF) in human and experimental sepsis, and to identify determinants of RBF.

Method

Using specific search terms we systematically interrogated two electronic reference libraries to identify experimental and human studies of sepsis and septic acute renal failure in which RBF was measured. In the retrieved studies, we assessed the influence of various factors on RBF during sepsis using statistical methods.

Results

We found no human studies in which RBF was measured with suitably accurate direct methods. Where it was measured in humans with sepsis, however, RBF was increased compared with normal. Of the 159 animal studies identified, 99 reported decreased RBF and 60 reported unchanged or increased RBF. The size of animal, technique of measurement, duration of measurement, method of induction of sepsis, and fluid administration had no effect on RBF. In contrast, on univariate analysis, state of consciousness of animals (P = 0.005), recovery after surgery (P < 0.001), haemodynamic pattern (hypodynamic or hyperdynamic state; P < 0.001) and cardiac output (P < 0.001) influenced RBF. However, multivariate analysis showed that only cardiac output remained an independent determinant of RBF (P < 0.001).

Conclusion

The impact of sepsis on RBF in humans is unknown. In experimental sepsis, RBF was reported to be decreased in two-thirds of studies (62 %) and unchanged or increased in one-third (38%). On univariate analysis, several factors not directly related to sepsis appear to influence RBF. However, multivariate analysis suggests that cardiac output has a dominant effect on RBF during sepsis, such that, in the presence of a decreased cardiac output, RBF is typically decreased, whereas in the presence of a preserved or increased cardiac output RBF is typically maintained or increased.

Intravital intestinal videomicroscopy: Techniques and experiences

Intravital videomicroscopy (IVM) of the gastrointestinal (GI) tract is a sophisticated and powerful technique to directly observe the neurologically intact microvasculature of rats in naive and pathological conditions. We combine IVM with other techniques (i.e., vascular ring tension analysis and colorimetric microsphere determination of whole organ blood flow) to develop a strategy for the systematic analysis of the regulation of GI blood flow in healthy animals and in models of systemic sepsis and resuscitated hemorrhagic shock. We also study the molecular biology of the GI tract (enzyme- or radio-linked immunosorbent assays, fluorescent Greiss assay, and immunoblots) to correlate expression and levels of vascular mediators in tissue and arterial, venous, and portal blood with functional activity of the GI microvascular tree. When combined, these techniques develop a picture of gut pathophysiology at the level of the endothelium, vascular smooth muscle cells, and blood cells in the microcirculation. Our work led us to the general hypothesis that altered microcirculatory function in disease states lies primarily at the level of the interface between vascular and tissue physiology, i.e., the endothelial cell. This review focuses on methods and techniques for studying microvascular function, and concludes with focused reviews of pertinent findings.

Oxidative stress and gene expression in sepsis

Dysregulation of the immuno-inflammatory response, as seen in sepsis, may culminate in host cell and organ damage. Lipopolysaccharide from Gram-negative bacterial cell walls induces gene activation and subsequent inflammatory mediator expression. Gene activation is regulated by a number of transcription factors at the nuclear level, of which nuclear factor kappaB appears to have a central role. The redox (reduction-oxidation) cellular balance is important for normal cellular function, including transcription factor regulation. In sepsis, a state of severe oxidative stress is encountered, with host endogenous antioxidant defences overcome. This has implications for cellular function and the regulation of gene expression. This review gives an overview of the mechanisms by which transcription factor activation and inflammatory mediator overexpression occur in sepsis, together with the events surrounding the state of oxidative stress encountered and the effects on the host's antioxidant defences. The effect of oxidative stress on transcription factor regulation is considered, together with the role of antioxidant repletion in transcription factor activation and in sepsis in general. Other interventions that may modulate transcription factor activation are also highlighted.

Pentoxifylline for neonatal sepsis

BACKGROUND

Although the overall incidence of neonatal sepsis has declined over the past decade, mortality remains high in the pre term infant. The high level of mortality and morbidity from sepsis despite the use of potent anti-microbial agents, and the global emergence of antibiotic resistance, have led to the search for new modalities to boost new born host defences. Pentoxifylline, a xanthine derivative and a phosphodiesterase inhibitor, has been shown to possess a broad spectrum of activity modulating inflammation.

OBJECTIVES

The primary objective was to assess the effect on mortality and the safety of intravenous pentoxifylline as an adjunct to antibiotic therapy in neonates with suspected or confirmed sepsis.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2002), MEDLINE, EMBASE and CINAHL were searched in October 2002 and again in March 2003. Science Citation Index for articles referencing Lauterbach 1996 and Lauterbach 1999 was searched as well as proceedings of the Pediatric Academic Societies which were published in Pediatric Research from 1980. Doctoral dissertations and theses were searched from 1980. The reference lists of identified RCTs, and personal files were searched. No language restriction was applied.

SELECTION CRITERIA

Studies were included if they were randomised or quasi-randomised trials, assessing the efficacy of pentoxifylline compared to placebo or no intervention as an adjunct to antibiotic therapy of suspected or confirmed sepsis in newborn infants less than 28 days old. Eligible trials were required to report treatment effects on at least one of the following outcomes: all cause mortality during initial hospital stay, neurological development at two years of age or later, length of hospital stay, duration of ventilation via endotracheal intubation, chronic lung disease in survivors, periventricular leukomalacia, necrotising enterocolitis, or adverse events.

DATA COLLECTION AND ANALYSIS

Two reviewers independently abstracted information for the outcomes of interest. Any differences were resolved by mutual discussion. Typical Relative Risk (RR) and Risk Difference (RD) with 95% confidence intervals (CI) using fixed effects model are reported for dichotomous outcomes. NNT was calculated for outcomes for which there was a statistically significant reduction in RD.

MAIN RESULTS

Two RCTs enrolled a total of 140 preterm (< 36 weeks) neonates with suspected late onset (> 7 days) sepsis to evaluate the effect of pentoxifylline on neonatal outcomes. However, the two studies reported outcomes of only the 107 randomised patients with confirmed sepsis. The results showed a reduction in 'all cause mortality during hospital stay' following pentoxifylline treatment [typical RR 0.14 (95% CI 0.03, 0.76), RD -0.16 (95% CI -0.27, - 0.04), NNT 6 (95% CI 4, 25)]. No adverse effects due to pentoxifylline were observed in the two included trials. No other outcomes of interest were reported.

REVIEWER'S CONCLUSIONS

Current evidence suggests that the use of pentoxifylline as an adjunct to antibiotics in neonatal sepsis reduces mortality without any adverse effects. But the number of neonates studied is small and considerable methodological weaknesses exist in the included trials. Hence these results should be interpreted with caution. Researchers are encouraged to undertake large well-designed trials to confirm or refute the effectiveness of pentoxifylline to reduce mortality and adverse outcomes in neonates with suspected or confirmed neonatal sepsis. Researchers might also compare pentoxifylline with other adjuncts to antibiotics which modulate inflammation (e.g. intravenous immunoglobulins, haematopoetic colony stimulating factors among others) in reducing mortality and morbidity due to neonatal sepsis.

Lazaroid and pentoxifylline suppress sepsis-induced increases in renal vascular resistance via altered arachidonic acid metabolism

Early sepsis leads to renal hypoperfusion, despite a hyperdynamic systemic circulation. It is thought that failure of local control of the renal microcirculation leads to hypoperfusion and organ dysfunction. Of the many mediators implicated in the pathogenesis of microvascular vasoconstriction, arachidonic acid metabolites are thought to be important. Vasoconstriction may be due to excess production of vasoconstrictors or loss of vasodilators. Using the isolated perfused kidney model, we describe a sepsis-induced rise in renal vascular resistance and increased production of key arachidonic acid metabolites, both vasoconstrictors and vasodilators, suggesting excessive production of vasoconstrictors as a cause for microcirculatory hypoperfusion. There is evidence of increased enzymatic production of arachidonic acid metabolites as well as nonenzymatic, free radical, catalyzed conversion of arachidonic acid. Pentoxifylline (a phosphodiesterase inhibitor) and U74389G (an antioxidant) both have a protective effect on the renal microcirculation during sepsis. Both drugs appear to alter the renal microvascular response to sepsis by altering renal arachidonic acid metabolism. This study demonstrates that sepsis leads to increased renal vascular resistance. This response is in part mediated by metabolites produced by metabolism of arachidonic acid within the kidney. The ability of drugs to modulate arachidonic acid metabolism and so alter the renal response to sepsis suggests a possible role for these agents in protecting the renal microcirculation during sepsis.

Regulation of intestinal blood flow

The gastrointestinal system anatomically is positioned to perform two distinct functions: to digest and absorb ingested nutrients and to sustain barrier function to prevent transepithelial migration of bacteria and antigens. Alterations in these basic functions contribute to a variety of clinical scenarios. These primary functions intrinsically require splanchnic blood flow at both the macrovascular and microvascular levels of perfusion. Therefore, a greater understanding of the mechanisms that regulate intestinal vascular perfusion in the normal state and during pathophysiological conditions would be beneficial. The purpose of this review is to summarize the current understanding regarding the regulatory mechanisms of intestinal blood flow in fasted and fed conditions and during pathological stress.

Microcirculatory dysfunction in sepsis: a pathogenetic basis for therapy?

Sepsis is a frequent complication of multiple organ dysfunction syndrome and remains a major problem of intensive care medicine. It is also a common factor in the final cause of death in hospital populations. Clinical observations, assisted by invasive monitoring techniques as well as pathological-anatomical studies, clearly indicate that microcirculatory dysfunction lies at the centre of sepsis pathogenesis. Numerous animal models, from rodents to primates, many of which employ bacteria or their toxins, especially endotoxins, have helped to shed light on the pathomechanisms leading to this dysregulation in the peripheral circulation. Among these are activation of humoral and cellular inflammatory mediator systems, with special emphasis on neutrophil-endothelial interactions, affecting endothelial barrier function and vasoregulation and ultimately leading to severely perturbed oxygen transport and utilization. In vitro studies have provided more insight into the molecular mechanisms involved in this microcirculatory dysfunction, although much more attention must be directed towards microvascular endothelial cells and the role of heterogeneity of response in various vascular beds. These experimental data must in turn be validated by comparing with the human in situ situation, both clinical and morphological. This review aims at a critical appraisal of the clinical and experimental evidence for sepsis-induced dysregulation of the microcirculation and how knowledge of the underlying cellular and molecular pathology could be used to make therapy more rational and effective. To date, therapeutic approaches, such as anti-cytokine and anti-oxidant regimens, which have been highly successful in experimental models, have failed to demonstrate clinical efficacy. Newer approaches, such as targeting the coagulation system, nitric oxide synthesis or intracellular signal transduction, are also discussed. The necessity to focus on the role of anti-inflammatory mediators, as well as the pathogenetic significance of important molecular groups, such as the heat shock proteins, which until now have been given scant attention, will be stressed.

Protective effects of Glycyrrhizae radix extract and its compounds in a renal hypoxia (ischemia)-reoxygenation (reperfusion) model

Glycyrrhizae radix water extract (GRWE) and its two major constituents glycyrrhizin and 3-glycyrrhetinic monodesmoside, significantly suppressed LDH leakage and MDA release, whereas glycyrrhetinic acid had no effect. On the other hand, in rats subjected to ischemia-reperfusion, the activities of endogenous antioxidant enzymes including catalase and glutathione peroxidase showed recovery, whereas the levels of urea nitrogen and creatinine in serum were reduced by administration of glycyrrhizin orally for 30 days prior to ischemia-reperfusion. These results indicate that GRWE and its two constituents may be promising for amelioration of hypoxia (ischemia)-reoxygenation (reperfusion) injury and improvement of renal function by acting directly or indirectly as antioxidant and oxygen radical-scavenging agents.

Total plasma antioxidant capacity is not always decreased in sepsis

OBJECTIVE

To compare total plasma antioxidant capacity and selected individual antioxidants in patients with varying degrees of severity of sepsis.

DESIGN

A prospective, observational, consecutive case study.

SETTING

A 16-bed intensive care unit (ICU) in a university teaching hospital.

INTERVENTIONS

None.

PATIENTS

Forty-six healthy controls, ten ICU patients, nine patients with systemic inflammatory response syndrome (SIRS), 11 septic patients, and 14 septic shock patients. Plasma was obtained in healthy patients scheduled for minor surgery immediately before anesthesia and in ICU patients within 24 hrs of admittance to the unit or diagnosis of SIRS, sepsis, or septic shock.

MEASUREMENTS AND MAIN RESULTS

Using the total peroxyl radical trapping method, we found plasma antioxidant capacity to be lower in septic patients but higher in septic shock patients, as compared with controls. Bilirubin was the greatest contributor to the increase with shock, followed by uric acid. Neopterin also correlated with the peroxyl radical trapping antioxidant parameter values.

CONCLUSION

Although total plasma antioxidant capacity is decreased from normal levels in septic patients, an increase in some oxidants contributes to an increased total antioxidant capacity in septic shock patients.