Hydroxyethyl starch exhibits antiinflammatory effects in the intestines of endotoxemic rats

Preeclamptic programming unevenly perturbs inflammatory and renal vasodilatory outcomes of endotoxemia in rat offspring: modulation by losartan and pioglitazone

Introduction: Preeclampsia (PE) enhances the vulnerability of adult offspring to serious illnesses. The current study investigated whether preeclamptic fetal programming impacts hemodynamic and renal vasodilatory disturbances in endotoxic adult offspring and whether these interactions are influenced by antenatal therapy with pioglitazone and/or losartan. Methods: PE was induced by oral administration of L-NAME (50 mg/kg/day) for the last 7 days of pregnancy. Adult offspring was treated with lipopolysaccharides (LPS, 5 mg/kg) followed 4-h later by hemodynamic and renovascular studies. Results: Tail-cuff measurements showed that LPS decreased systolic blood pressure (SBP) in male, but not female, offspring of PE dams. Moreover, PE or LPS reduced vasodilations elicited by acetylcholine (ACh, 0.01-7.29 nmol) or N-ethylcarboxamidoadenosine (NECA, 1.6-100 nmol) in perfused kidneys of male rats only. The latter effects disappeared in LPS/PE preparations, suggesting a postconditioning action for LPS against renal manifestation of PE. Likewise, elevations caused by LPS in serum creatinine and inflammatory cytokines (TNFα and IL-1β) as well as in renal protein expression of monocyte chemoattractant protein-1 (MCP-1) and AT1 receptors were attenuated by the dual PE/LPS challenge. Gestational pioglitazone or losartan reversed the attenuated ACh/NECA vasodilations in male rats but failed to modify LPS hypotension or inflammation. The combined gestational pioglitazone/losartan therapy improved ACh/NECA vasodilations and eliminated the rises in serum IL-1β and renal MCP-1 and AT1 receptor expressions. Conclusion: Preeclamptic fetal programming of endotoxic hemodynamic and renal manifestations in adult offspring depends on animal sex and specific biological activity and are reprogrammed by antenatal pioglitazone/losartan therapy.

Short-lived sensitization of cardiovascular outcomes of postpartum endotoxemia in preeclamptic rats: Role of medullary solitary tract neuroinflammation

Preeclampsia (PE) is a pregnancy-related disorder with serious maternal complications. Considering the increased importance of postpartum infection in maternal morbidity and mortality, we investigated whether preeclamptic maternal programming alters cardiovascular consequences of endotoxemia in rats and the role of cardiac and brainstem neuroinflammation in this interaction. Preeclampsia was induced by oral administration of L-NAME (50 mg/kg/day) for 7 days starting from day 14 of conception. Changes in blood pressure, heart rate, and cardiac autonomic function caused by lipopolysaccharide (LPS, 5 mg/kg i.v.) were assessed in mothers at 3 weeks (weaning time) and 9 weeks postnatally. Compared with respective non-PE counterparts, LPS treatment of weaning PE mothers caused significantly greater (i) falls in blood pressure, (ii) rises in heart rate and left ventricular contractility (dP/dt_max), (iii) reductions in time and frequency domain indices of heart rate variability and shifts in cardiac sympathovagal balance (low-frequency/high-frequency ratio, LF/HF) towards parasympathetic dominance, and (iv) attenuation of reflex bradycardic responses measured by the vasoactive method. The intensified LPS effects in weaning PE rats subsided after 9 weeks of delivery. Immunohistochemical studies showed increased protein expression of nuclear factor kappa B (NF-κB) in brainstem neuronal pools of the nucleus of the solitary tract (NTS), but not rostral ventrolateral medulla (RVLM), in endotoxic PE weaning rats compared with non-PE rats. Cardiac NF-κB expression was increased by LPS but this was similarly noted in PE and non-PE rats. Together, preeclamptic maternal programming elicits short-term exacerbation of endotoxic cardiovascular and autonomic derangements due possibly to exaggerated NTS neuroinflammatory insult.

Hydroxyethyl starch based smart nanomedicine

In the past decades, the vigorous development of nanomedicine has opened up a new world for drug delivery. Hydroxyethyl starch (HES), a clinical plasma volume expander which has been widely used for years, is playing an attracting role as drug carriers. Compared with all other polysaccharides, HES has proven its unique characteristics for drug delivery platforms, including good manufacture practice, biodegradability, biocompatibility, abundant groups for chemical modification, excellent water solubility, and tailorability. In this review, an overview of various types of HES based drug delivery systems is provided, including HES-drug conjugates, HES-based nano-assemblies, HES-based nanocapsules, and HES-based hydrogels. In addition, the current challenges and future opportunities for design and application of HES based drug delivery systems are also discussed. The available studies show that HES based drug delivery systems has significant potential for clinical translation.

Pre-eclamptic Fetal Programming Alters Neuroinflammatory and Cardiovascular Consequences of Endotoxemia in Sex-Specific Manners

Pre-eclampsia (PE)-induced fetal programming predisposes offspring to health hazards in adult life. Here, we tested the hypothesis that pre-eclamptic fetal programming elicits sexually dimorphic inflammatory and cardiovascular complications to endotoxemia in adult rat offspring. PE was induced by oral administration of L-NAME (50 mg/kg per day for seven consecutive days) starting from day 14 of conception. Cardiovascular studies were performed in conscious adult male and female offspring preinstrumented with femoral indwelling catheters. Compared with non-PE male counterparts, intravenous administration of lipopolysaccharide (LPS, 5 mg/kg) to PE male offspring caused significantly greater 1) falls in blood pressure, 2) increases in heart rate, 3) rises in arterial dP/dtmax, a correlate of left ventricular contractility, and 4) decreases in time- and frequency-domain indices of heart rate variability (HRV). By contrast, the hypotensive and tachycardic actions of LPS in female offspring were independent of the pre-eclamptic state and no clear changes in HRV or dP/dtmax were noted. Measurement of arterial baroreflex activity by vasoactive method revealed no sex specificity in baroreflex dysfunction induced by LPS. Immunohistochemical studies showed increased protein expression of toll-like receptor 4 in heart as well as in brainstem neuronal pools of the nucleus of solitary tract and rostral ventrolateral medulla in endotoxic PE male, but not female, offspring. Enhanced myocardial, but not neuronal, expression of monocyte chemoattractant protein-1 was also demonstrated in LPS-treated male offspring. Together, pre-eclamptic fetal programming aggravates endotoxic manifestations of hypotension and autonomic dysfunction in male offspring via exacerbating myocardial and neuromedullary inflammatory pathways. SIGNIFICANCE STATEMENT: Current molecular and neuroanatomical evidence highlights a key role for pre-eclamptic fetal programming in offspring predisposition to health hazards induced by endotoxemia in adult life. Pre-eclampsia accentuates endotoxic manifestations of hypotension, tachycardia, and cardiac autonomic dysfunction in male offspring via exacerbating myocardial and central inflammatory pathways. The absence of such detrimental effects in female littermates suggests sexual dimorphism in the interaction of pre-eclamptic fetal programming with endotoxemia.

Hydroxyethyl starch: a review of pharmacokinetics, pharmacodynamics, current products, and potential clinical risks, benefits, and use

OBJECTIVE

To review and summarize the pharmacokinetics and pharmacodynamics of hydroxyethyl starch (HES), as well as reported risks and benefits of HES infusion, and to provide administration and monitoring recommendations for HES use in dogs and cats.

DATA SOURCES

Veterinary and human peer-reviewed medical literature, including scientific reviews, clinical and laboratory research articles, and authors' clinical experience.

SUMMARY

HES solutions are the most frequently used synthetic colloid plasma volume expanders in human and veterinary medicine. The majority of research in human medicine has focused on the adverse effects of HES infusion, with emphasis on acute kidney injury and coagulation derangements. The studies often differ in or fail to report factors, such as the type, amount, interval, and concentration of HES administered; the patient population studied; or concurrent fluids administered. Currently, there is no definitive clinical evidence that the reported adverse effects of HES use in human medicine occur in veterinary species. There is little information available on HES administration techniques or simultaneous administration of additional fluids in human and veterinary medicine. The rationale for HES use in small animals has been largely extrapolated from human medical studies and guidelines. A controlled approach to intravenous fluid resuscitation using crystalloid and HES volumes titrated to reach desired resuscitation end point parameters is outlined for small animal practitioners.

CONCLUSION

The extrapolation of data from human studies directly to small animals should be done with the knowledge that there may be species variations and different pharmacokinetics with different HES solutions. Veterinary reports indicate that bolus and continuous rate infusions of 6% hetastarch solutions at moderate doses are well tolerated in feline and canine subjects. Further research in domesticated species is necessary to better define and expand the knowledge regarding use of HES solutions in small animal medicine.

Hypometabolism and hypothermia in the rat model of endotoxic shock: independence of circulatory hypoxia

We tested the hypothesis that development of hypothermia instead of fever in endotoxic shock is consequential to hypoxia. Endotoxic shock was induced by bacterial lipopolysaccharide (LPS, 500 μg kg(-1) i.v.) in rats at an ambient temperature of 22 °C. A β3-adrenergic agonist known to activate metabolic heat production, CL316,243, was employed to evaluate whether thermogenic capacity could be impaired by the fall in oxygen delivery (ḊO2) during endotoxic shock. This possibility was rejected as CL316,243 (0.15 mg kg(-1) i.v.) evoked similar rises in oxygen consumption (V̇O2) in the presence and absence of endotoxic shock. Next, to investigate whether a less severe form of circulatory hypoxia could be triggering hypothermia, the circulating volume of LPS-injected rats was expanded using 6% hetastarch with the intention of improving tissue perfusion and alleviating hypoxia. This intervention attenuated not only the fall in arterial pressure induced by LPS, but also the associated falls in V̇O2 and body temperature. These effects, however, occurred independently of hypoxia, as they were not accompanied by any detectable changes in NAD(+)/NADH ratios. Further experimentation revealed that even the earliest drops in cardiac output and ḊO2 during endotoxic shock did not precede the reduction in V̇O2 that brings about hypothermia. In fact, ḊO2 and V̇O2 fell in such a synchrony that the ḊO2/V̇O2 ratio remained unaffected. Only when hypothermia was prevented by exposure to a warm environment (30 °C) did an imbalance in the ḊO2/V̇O2 ratio become evident, and such an imbalance was associated with reductions in the renal and hypothalamic NAD(+)/NADH ratios. In conclusion, hypometabolism and hypothermia in endotoxic shock are not consequential to hypoxia but serve as a pre-emptive strategy to avoid hypoxia in this model.

Comparison of Hb-200 and 6% hetastarch 450/0.7 during initial fluid resuscitation of 20 dogs with gastric dilatation-volvulus

OBJECTIVE

To compare the use of polymerized stroma-free bovine hemoglobin (Hb-200) and 6% hetastarch 450/0.7 (HES 450/0.7) in 0.9% saline during fluid resuscitation of dogs with gastric dilatation-volvulus (GDV).

DESIGN

Prospective, randomized clinical case series.

SETTING

Private specialty and referral clinic.

ANIMALS

Twenty client-owned dogs presenting with GDV.

INTERVENTIONS

Dogs presenting with GDV and abnormal perfusion parameters first received rapid IV infusion of a buffered isotonic replacement crystalloid (15 mL/kg) and IV opioids. Patients were then randomized to receive either Hb-200 (N = 10) or HES 450/0.7 (N = 10). Balanced isotonic replacement crystalloids (10-20 mL/kg IV) were rapidly infused along with either Hb-200 or HES in 5 mL/kg IV aliquots to meet resuscitation end points.

MEASUREMENTS AND MAIN RESULTS

Resuscitation was defined as meeting at least 2 of 3 criteria: (1) capillary refill time 1-2 seconds, pink mucous membrane color, strong femoral pulse quality; (2) heart rate (HR) ≤ 150/min; or (3) indirect arterial systolic blood pressure (SBP) > 90 mm Hg. HR, SBP, packed cell volume, hemoglobin, glucose, venous pH, bicarbonate, base excess, anion gap, and colloid osmotic pressure were compared at hospital entry and within 30 minutes post-resuscitation. Compared to the HES group, the Hb-200 group required significantly less colloid (4.2 versus 18.4 mL/kg) and crystalloid (31.3 versus 48.1 mL/kg) to reach resuscitation end points (P = 0.001). Time to resuscitation was significantly shorter in the Hb-200 group (12.5 versus 52.5 min).

CONCLUSIONS

Dogs with GDV receiving Hb-200 during initial resuscitation required smaller volumes of both crystalloid and colloid fluids and reached resuscitation end points faster than dogs receiving HES 450/0.7 (P = 0.02).

Effects of crystalloids and colloids on liver and intestine microcirculation and function in cecal ligation and puncture induced septic rodents

Background

Septic acute liver and intestinal failure is associated with a high mortality. We therefore investigated the influence of volume resuscitation with different crystalloid or colloid solutions on liver and intestine injury and microcirculation in septic rodents.

Methods

Sepsis was induced by cecal ligation and puncture (CLP) in 77 male rats. Animals were treated with different crystalloids (NaCl 0.9% (NaCl), Ringer’s acetate (RA)) or colloids (Gelafundin 4% (Gel), 6% HES 130/0.4 (HES)). After 24 h animals were re-anesthetized and intestinal (n = 6/group) and liver microcirculation (n = 6/group) were obtained using intravital microscopy, as well as macrohemodynamic parameters were measured. Blood assays and organs were harvested to determine organ function and injury.

Results

HES improved liver microcirculation, cardiac index and DO₂-I, but significantly increased IL-1β, IL-6 and TNF-α levels and resulted in a mortality rate of 33%. Gel infused animals revealed significant reduction of liver and intestine microcirculation with severe side effects on coagulation (significantly increased PTT and INR, decreased haemoglobin and platelet count). Furthermore Gel showed severe hypoglycemia, acidosis and significantly increased ALT and IL-6 with a lethality of 29%. RA exhibited no derangements in liver microcirculation when compared to sham and HES. RA showed no intestinal microcirculation disturbance compared to sham, but significantly improved the number of intestinal capillaries with flow compared to HES. All RA treated animals survided and showed no severe side effects on coagulation, liver, macrohemodynamic or metabolic state.

Conclusions

Gelatine 4% revealed devastated hepatic and intestinal microcirculation and severe side effects in CLP induced septic rats, whereas the balanced crystalloid solution showed stabilization of macro- and microhemodynamics with improved survival. HES improved liver microcirculation, but exhibited significantly increased pro-inflammatory cytokine levels. Crystalloid infusion revealed best results in mortality and microcirculation, when compared with colloid infusion.

HES 130/0.4 impairs haemostasis and stimulates pro-inflammatory blood platelet function

Introduction

Hydroxyethyl starch (HES) solutions are widely used for volume replacement therapy but are also known to compromise coagulation, impair renal function and increase long-term mortality. To test the hypotheses that HES 130/0.4 has fewer adverse effects than HES 200/0.5 and exerts anti-inflammatory properties, we compared the effects of HES 130/0.4, HES 200/0.5 and saline on in vitro haemostasis and pro-inflammatory platelet function.

Methods

Whole blood samples from healthy volunteers were mixed with 6% HES 130/0.4, 10% HES 200/0.5, or normal saline to achieve a final haemodilution rate of 10% or 40%. Haemostatic capacity was characterised by thromboelastography (ROTEM) and measurement for FXIIIa activity. Platelet activation and pro-inflammatory platelet functions were characterised by flow cytometry measuring the platelet activation marker CD62P and binding of fibrinogen to platelets as well as the formation of heterotypic platelet-leukocyte conjugates.

Results

Compared with saline, HES 130/0.4 dose-dependently impaired formation and firmness of the fibrin clot but did not affect the fibrin crosslinking activity of FXIIIa. At 40% but not at 10% haemodilution rate, HES 200/0.5 also increased platelet fibrinogen binding and both HES solutions increased expression of CD62P, the main receptor for platelet-leukocyte adhesion. HES 130/0.4 but not HES 200/0.5 increased formation of platelet-neutrophil conjugates and, to a lesser degree, platelet-monocyte conjugates.

Conclusions

Our data demonstrate that HES 130/0.4 has similar adverse effects as HES 200/0.5. In particular, both types of HES impair coagulation capacity and stimulate, rather than attenuate, pro-inflammatory platelet function.

Effects of acute hypervolaemic haemodilution on the expression of plasma interferon-inducible protein-10 and bactericidal/permeability-increasing protein in patients undergoing total hip replacement

This prospective, randomized controlled study evaluated the effects of acute hypervolaemic haemodilution (AHH) on the expression of plasma interferon-inducible protein-10 (IP-10) and bactericidal/permeability-increasing protein (BPI) in patients undergoing elective total hip replacement. Twenty patients were randomized to receive an infusion of either hydroxyethyl starch (HES group) or lactated Ringer's solution (LR group) immediately after anaesthesia. Plasma concentrations of IP-10 and BPI were measured before anaesthesia (baseline), at the start of surgery, 30 min after the start of surgery and at the end of surgery. Blood loss and the volume of blood transfused were significantly lower in the HES group compared with the LR group. Compared with baseline, IP-10 and BPI concentrations increased significantly in both groups 30 min after the start of surgery. The IP-10 concentrations were significantly lower and BPI concentrations significantly higher in the HES group compared with the LR group 30 min after the start of surgery and at the end of surgery. It is concluded that AHH with HES may be helpful in ameliorating immune function during total hip replacement and in reducing blood loss and the extent of blood transfusion.

Postoperative ileus: pathogenesis and treatment

Surgical manipulation of the intestines activates intestinal macrophages that release cytokines and nitric oxide, which results in inhibition of intestinal motility. Subsequent infiltration of circulating leukocytes into the intestinal wall contributes to cytokine and nitric oxide release and exacerbates ileus. Other factors contributing to ileus are endotoxemia; edema of the intestine wall subsequent to excessive fluid therapy; hypocalcemia; and long abdominal incisions. Because treatment of ileus with prokinetic drugs has not proven to be very effective, efforts should be directed at reducing its severity. Strategies which reduce the severity of ileus include pretreatment with a nonsteroidal anti-inflammatory drug, minimizing the length of the abdominal incision, reducing intestinal manipulation, intraoperative lidocaine infusion, correction of hypocalcemia, limiting the volume of intravenous fluids to prevent intestinal edema, and administration of alpha(2) antagonists.

Hydroxyethyl starch 130/0.4 inhibits production of plasma proinflammatory cytokines and attenuates nuclear factor-kappaB activation and Toll-like receptors expression in monocytes during sepsis

BACKGROUND

Hydroxyethyl starch (HES) is one of the most frequently used plasma substitutes, and could modulate inflammatory response in sepsis. Our aim of this study was to investigate the mechanism of the effect of HES 130/0.4 by studying plasma levels of inflammatory cytokines, nuclear factor-kappaB (NF-kappaB) activation, and Toll-like receptors (TLRs) expression in peripheral monocytes during polymicrobial sepsis.

MATERIALS AND METHODS

Rats with sepsis induced by cecal ligation and puncture (CLP) were treated with HES130/0.4 (7.5, 15, or 30 mL/kg, intravenously); then, rat plasma and monocytes were isolated from blood 5 h later. The plasma level of cytokines (tumor necrosis factor [TNF]-alpha and interleukin [IL]-6), NF-kappaB activity, and mRNA and protein levels of TLRs (TLR2 and TLR4) in peripheral blood monocytes were determined by enzyme-linked immunosorbent assay, electrophoretic mobility shift assay, reverse transcription-polymerase chain reaction, and Western blotting, respectively.

RESULTS

HES130/0.4 dose-dependently reduced the plasma level of TNF-alpha and IL-6 in rats with sepsis. HES130/0.4 also significantly inhibited NF-kappaB activation, and TLRs mRNA and protein levels in peripheral monocytes.

CONCLUSION

During sepsis, HES130/0.4 can down-regulate the inflammatory response, possibly through inhibition of the TLRs/NF-kappaB signaling pathway, and could be one more appropriate plasma substitute in sepsis.

[Hemorrhagic shock]

Hemorrhagic shock is a condition produced by rapid and significant loss of blood which lead to hemodynamic instability, decreases in oxygen delivery, decreased tissue perfusion, cellular hypoxia, organ damage and can be rapidly fatal. Despite improved understanding of the pathophysiology and significant advances in technology, it remains a serious problem associated with high morbidity and mortality. Early treatment is essential but is hampered by the fact that signs and symptoms of shock appear only after the state of shock is well establish and the compensatory mechanisms have started to fail. The primary goal is to stop the bleeding and restore the intravascular volume. This review addresses the pathophysiology and treatment of haemorrhagic shock.