Desflurane versus propofol in post-operative quality of recovery of patients undergoing day laparoscopic cholecystectomy. Prospective, comparative, non-inferiority study

OBJECTIVE

Recently, the evaluation of postoperative results has focused on the opinion of the patient as of great relevance. Our objective was to evaluate the quality of recovery by questionnaire (QoR-15) in patients undergoing laparoscopic cholecystectomy, comparing desflurane versus a total intravenous technique with propofol (TIVA). A non-inferiority hypothesis was proposed between both techniques.

MATERIAL AND METHODS

Prospective longitudinal cohort study in patients undergoing laparoscopic cholecystectomy in which multimodal management was applied including low pneumoperitoneum pressures, deep neuromuscular block and pain prevention strategy and PONV. Anaesthesia maintenance was performed with either desflurane or propofol at the discretion of the anaesthesiologist. QoR-15 was evaluated pre-and 24hours after surgery.

RESULTS

Sixty-one patients were evaluated: 29 in the desflurane group and 32 in the TIVA group with no differences in demographic parameters, ASA grade, and preoperative QoR-15 questionnaire. The duration of the intervention was superior in TIVA group, 55 ± 15 vs. 45 ± 9min in desflurane group; p =.05. The desflurane group received more fentanyl than the TIVA group: 200 ± 65 vs. 113 ± 38μg; p =.05. No differences in pain, PONV or time of stay between groups. QoR-15 at 24h decreased 7% relative to baseline, with no differences between groups.

CONCLUSIONS

The quality of recovery evaluated by the patient was as favourable in the patients of the desflurane group as in those of the TIVA group in patients undergoing laparoscopic cholecystectomy as outpatients.

Unique challenges and experiences of trainees from Reach-the-World countries

I am fortunate to have received a Reach-the-World (RTW) fellowship from the International Society on Thrombosis and Haemostasis (ISTH) in 2014 to continue my training in thrombosis and inflammation. I believe that the RTW fellowship is an important educational opportunity for young professionals from developing countries, and I hope to encourage other scientists to apply for this career-changing opportunity by sharing my story.

Stimulation of PAR-1 or PAR-4 promotes similar pattern of VEGF and endostatin release and pro-angiogenic responses mediated by human platelets

BACKGROUND

Platelets mediate angiogenesis through the secretion of several factors, including the pro-angiogenic vascular endothelial growth factor (VEGF) and the anti-angiogenic endostatin. Although previous findings indicated that these molecules are packed into different alpha-granules and selectively released by specific stimulation of protease-activated receptor (PAR)-1 or PAR-4, recent evidences are against this hypothesis.

OBJECTIVES

To elucidate the controversies about the VEGF and endostatin release and the overall angiogenic effect of PARs-stimulated platelets.

METHODS

VEGF and endostatin were quantified by enzyme linked-immunosorbent assay (ELISA). Endothelial proliferation (pNPP assay), wound healing (scratch assay) and tubule formation (matrigel) of human microvascular endothelial cells (HMEC-1) and endothelial progenitor cells (EPC) were determined using supernatants from PAR-1- or PAR-4-stimulated platelets.

RESULTS

Activation of washed platelets (WPs) by PAR-1- or PAR-4-activating peptide (AP) promoted the VEGF and endostatin secretion in a concentration-dependent manner, being PAR-1-AP more potent than PAR-4-AP. The release of both molecules was abrogated by pre-incubation of platelets with PAR antagonists. Activation of platelet-rich plasma (PRP) with either PAR-1-AP or PAR-4-AP induced a significant VEGF secretion. Quantification of platelet-endostatin secretion was not possible in PRP due to the high levels of plasmatic endostatin vs. platelet content. Releasates from PAR-1- or PAR-4-activated WPs promoted similar pattern of angiogenic responses of HMEC-1 or EPC. Moreover, proliferation of HMEC-1 mediated by PAR-stimulated PRP releasates was delayed and significantly lower compared with that induced by PAR-stimulated WPs.

CONCLUSIONS

Our results are in contrast with the previously described differential release of VEGF and endostatin induced by the selective PAR-1 or PAR-4 stimulation, and support the notion that while circulating endostatin accounts for the maintenance of a systemic anti-angiogenic state, locally, the release of platelet alpha-granule content promotes angiogenesis.

Expression and functionality of Toll-like receptor 3 in the megakaryocytic lineage

BACKGROUND

In addition to their key role in hemostasis, platelets and megakaryocytes regulate immune and inflammatory responses, in part through their expression of Toll-like receptors (TLRs). Among the TLRs, TLR3 recognizes dsRNA associated with viral infection. Thrombocytopenia is a frequent complication of viral infection. However, the expression and functionality of TLR3 in megakaryocytes and platelets is not yet well understood.

OBJECTIVE

To study the expression and functionality of TLR3 in the megakaryocytic lineage.

METHODS AND RESULTS

RT-PCR, flow cytometric and immunofluorescence assays showed that TLR3 is expressed in CD34(+) cells, megakaryocytes, and platelets. Immunoblotting assays showed that stimulation of megakaryocytes with two synthetic agonists of TLR3, Poly(I:C) and Poly(A:U), activated the nuclear factor-κB (NF-κB), phosphoinositide 3-kinase (PI3K)/Akt, extracellular signal-related kinase (ERK)1/2 and p38 pathways. TLR3-megakaryocyte activation resulted in reduced platelet production in vitro and interferon-β release through the PI3K-Akt and NF-κB signaling pathways. TLR3 ligands potentiated the aggregation mediated by classic platelet agonists. This effect was also observed for ATP release, but not for P-selectin or CD40L membrane exposure, indicating that TLR3 activation was not involved in α-granule release. In addition, TLR3 agonists induced activation of the NF-κB, PI3K-Akt and ERK1/2 pathways in platelets. Reductions in platelet production and platelet fibrinogen binding mediated by Poly(I:C) or Poly(A:U) were prevented by the presence of an inhibitor of the TLR3-dsRNA complex.

CONCLUSIONS

Our findings indicate that functional TLR3 is expressed in CD34(+) cells, megakaryocytes, and platelets, and suggest a potential role for this receptor in the megakaryopoiesis/thrombopoiesis alterations that occur in viral infections.

Platelet-mediated angiogenesis is independent of VEGF and fully inhibited by aspirin

BACKGROUND AND PURPOSE

Platelets are major players in every step of vessel development through the local delivery of angiogenesis-modulating factors, including the pro-angiogenic protein VEGF and the anti-angiogenic endostatin. Although thrombin is a potent agonist and is highly elevated in angiogenesis-related diseases, studies regarding its action on the release of platelet angiogenic factors are scarce and controversial. Herein, we have investigated the role of thrombin not only in VEGF and endostatin release but also in net platelet angiogenic activity.

EXPERIMENTAL APPROACH

Human platelets were stimulated with thrombin in the presence of the various inhibitors of the signalling pathways involved in platelet activation. Supernatants/releasates were used to determine the levels of angiogenic molecules and to induce angiogenic responses.

KEY RESULTS

We found that thrombin induced the secretion of both VEGF and endostatin; however, the overall effect of the releasates was pro-angiogenic as they promoted tubule-like formation and increased the proliferation of endothelial cells. Both responses were only slightly suppressed in the presence of a VEGF receptor-neutralizing antibody. Pharmacological studies revealed that while inhibitors of PKC, p38, ERK1/2, Src kinases or PI3K/Akt exerted only partial inhibitory effects, aspirin fully blocked the pro-angiogenic activity of the releasate.

CONCLUSIONS AND IMPLICATIONS

In contrast to current belief, platelet pro-angiogenic responses are independent of VEGF and appear to be the result of the combined action of several molecules. Moreover, our data reinforce the notion that aspirin is a good candidate for a therapeutic agent to treat angiogenesis-related diseases.

Expression and functionality of type I interferon receptor in the megakaryocytic lineage

BACKGROUND

Type I interferons (IFN-I) negatively regulate megakaryo/thrombopoiesis. However, expression of the IFN-I receptor (IFNAR) in the megakaryocytic lineage is poorly characterized.

OBJECTIVES

To study the expression and functionality of IFNAR in the megakaryocytic lineage.

METHODS AND RESULTS

Although IFNAR mRNA was found in every cell type studied, its protein expression showed differences between them. According to flow cytometry and immunofluorescence, IFNAR1 was observed in Meg-01, Dami, CD34+ cells and megakaryocytes, but not in proplatelets or platelets. Immunoblotting assays showed that IFNAR1 and IFNAR2 were highly expressed in all cell types, except in platelets where it was barely detectable. Regarding IFNAR1, 130- and 90-kDa bands were detected in Meg-01 and Dami, whereas 130- and 60-kDa bands were found in CD34+ cells and megakaryocytes. Activation of megakaryocytic IFNAR by IFN-β induced pSTAT1/2 and upregulated the antiviral genes IRF7 and MXA. The latter response was completely suppressed by IFNAR blockade. In contrast, the low levels of IFNAR in platelets were not functional as pSTAT1/2, aggregation and P-selectin expression were not induced by IFN-I. In addition, megakaryocytes increased IFN-I transcript levels and produced IFN-β upon stimulation with PolyI:C, a synthetic dsRNA that mimics viral infection.

CONCLUSIONS

Early progenitors and mature megakaryocytes, but not platelets, express functional IFNAR and synthetize/release IFN-β, revealing not only that megakaryo/thrombopoiesis regulation by IFN-I is associated with a specific interaction with its receptor, but also that megakaryocytes may play a role in the antiviral defense by being both IFN producers and responders.

Hyperthermia inhibits platelet hemostatic functions and selectively regulates the release of alpha-granule proteins

BACKGROUND

Hyperthermia is one of the main disturbances of homeostasis occurring during sepsis or hypermetabolic states such as cancer. Platelets are important mediators of the inflammation that accompanies these processes, but very little is known about the changes in platelet function that occur at different temperatures.

OBJECTIVES

To explore the effect of higher temperatures on platelet physiology.

METHODS

Platelet responses including adhesion, spreading (fluorescence microscopy), α(IIb)β(3) activation (flow cytometry), aggregation (turbidimetry), ATP release (luminescence), thromboxane A(2) generation, alpha-granule protein secretion (ELISA) and protein phosphorylation from different signaling pathways (immunoblotting) were studied.

RESULTS

Preincubation of platelets at temperatures higher than 37 °C (38.5-42 °C) inhibited thrombin-induced hemostasis, including platelet adhesion, aggregation, ATP release and thromboxane A(2) generation. The expression of P-selectin and CD63, as well as vascular endothelial growth factor (VEGF) release, was completely inhibited by hyperthermia, whereas von Willebrand factor (VWF) and endostatin levels remained substantially increased at high temperatures. This suggested that release of proteins from platelet granules is modulated not only by classical platelet agonists but also by microenvironmental factors. The observed gradation of response involved not only antiangiogenesis regulators, but also other cargo proteins. Some signaling pathways were more stable than others. While ERK1/2 and AKT phosphorylation were resistant to changes in temperature, Src, Syk, p38 phosphorylation and IkappaB degradation were decreased in a temperature-dependent fashion.

CONCLUSIONS

Higher temperatures, such as those observed with fever or tissue invasion, inhibit the hemostatic functions of platelets and selectively regulate the release of alpha-granule proteins.