Photocatalytic Hydrodecarboxylation of Fatty Acids for Drop-in Biofuels Production.

A mild, practical, and environmentally friendly method for the hydrodecarboxylation of fatty acids using an acridine-based photoredox catalyst and thiophenol was developed. Cn-1 alkanes were synthesized in good to excellent yields (up to 99 %) from C10-C18 saturated fatty acids under visible light irradiation (405 nm). The developed protocol was employed for a mixture of fatty acids obtained from the hydrolysis of Licuri oil, affording a mixture of C9-C17 hydrocarbons in quantitative yield, which demonstrates the potential application of the method to produce drop-in biofuels.

A Computational Approach Applied to the Study of Potential Allosteric Inhibitors Protease NS2B/NS3 from Dengue Virus.

Dengue virus (DENV) is a danger to more than 400 million people in the world, and there is no specific treatment. Thus, there is an urgent need to develop an effective method to combat this pathology. NS2B/NS3 protease is an important biological target due it being necessary for viral replication and the fact that it promotes the spread of the infection. Thus, this study aimed to design DENV NS2B/NS3pro allosteric inhibitors from a matrix compound. The search was conducted using the Swiss Similarity tool. The compounds were subjected to molecular docking calculations, molecular dynamics simulations (MD) and free energy calculations. The molecular docking results showed that two compounds, ZINC000001680989 and ZINC000001679427, were promising and performed important hydrogen interactions with the Asn152, Leu149 and Ala164 residues, showing the same interactions obtained in the literature. In the MD, the results indicated that five residues, Lys74, Leu76, Asn152, Leu149 and Ala166, contribute to the stability of the ligand at the allosteric site for all of the simulated systems. Hydrophobic, electrostatic and van der Waals interactions had significant effects on binding affinity. Physicochemical properties, lipophilicity, water solubility, pharmacokinetics, druglikeness and medicinal chemistry were evaluated for four compounds that were more promising, showed negative indices for the potential penetration of the Blood Brain Barrier and expressed high human intestinal absorption, indicating a low risk of central nervous system depression or drowsiness as the the side effects. The compound ZINC000006694490 exhibited an alert with a plausible level of toxicity for the purine base chemical moiety, indicating hepatotoxicity and chromosome damage in vivo in mouse, rat and human organisms. All of the compounds selected in this study showed a synthetic accessibility (SA) score lower than 4, suggesting the ease of new syntheses. The results corroborate with other studies in the literature, and the computational approach used here can contribute to the discovery of new and potent anti-dengue agents.

Case-fatality From Orally-transmitted Acute Chagas Disease: A Systematic Review and Meta-analysis.

Orally-transmitted acute Chagas disease (CD) is emerging as an important public health problem. The prognosis of acute infection following oral transmission is unknown. The aim of this study was to analyze and summarize data on orally-transmitted acute CD. We searched for publications from 1968 to 31 January 2018. We included studies and unpublished data from government sources that reported patients with acute orally-transmitted CD. We identified 41 papers and we added 932 unpublished cases. In all, our study covered 2470 cases and occurrence of 97 deaths. Our meta-analysis estimated that the case-fatality rate was 1.0% (95% CI 0.0-4.0%). Lethality rates have declined over time (P = .02). In conclusion, orally-transmitted acute CD has considerable lethality in the first year after infection. The lethality in symptomatic cases is similar to that from other routes of infection. The lethality rate of orally-acquired disease has declined over the years.

Evaluation of chelating and cytoprotective activity of vanillin against the toxic action of mercuric chloride as an alternative for phytoremediation.

Mercury is widely found in nature, however, in low concentrations, but anthropological activities have increased its concentration considerably. This causes various environmental hazards and human health. Many substances are capable of reversing the toxicity of mercuric chloride in the environment. The aim of the present study was to determine the chelating effect of vanillin, as well as to evaluate its capacity for cytoprotection in prokaryotic and eukaryotic plant models. Chelating activity was determined from vanillin's ability to reduce iron III ions. To evaluate cytoprotection in a unicellular prokaryotic and eukaryotic model, Escherichia coli and Candida albicans, respectively, were used. And to evaluate the cytoprotective activity in vegetables, lettuce seeds were submitted to different concentrations of mercuric chloride and its association with the sub-allelopathic concentration of vanillin (32 µg/mL). Vanillin has been found to have antioxidant activity as it can reduce iron III ions. The use of vanillin also allows for better growth and development of Lactuca sativa seed root and stem, also allowing better preservation of its biochemical structures. These results are quite important, as environmental contamination by heavy metals has increased dramatically and finding a viable alternative to grow vegetables in contaminated areas is very valid.

FTIR analysis of pyrogallol and phytotoxicity-reductive effect against mercury chloride.

Human activities, especially in industry, have contributed to soil contamination with heavy or toxic metals. The objective of this study was to determine the chelating effect and antioxidant activity of pyrogallol, as well as to evaluate its cytoprotective activity in prokaryotic and eukaryotic models, animal and plant, respectively, against toxic mercury chloride action. Antioxidant activity was determined by DPPH where pyrogallol showed considerable action, chelating even iron ions. For the microbiologic activity assays, microdilution was performed to obtain the minimal inhibitory concentration, minimum bactericidal and minimum fungicide concentration, from which the sub-inhibitory concentrations were determined. The product did not conferred cytoprotection to the tested bacteria and fungi. To evaluate plant cytoprotection, Lactuta sativa seeds were used together with the product at a sub-allelopathic concentration with different HgCl2 concentrations. In this case, the tannin conferred cytoprotection to the plant model, allowing the best growth and development of caulicles and radicles, thus preserving tissues necessary for plant survival. From the results, it is observable that pyrogallol possesses cytoprotective action in the eukaryotic plant model, this action being useful as an alternative which favors the growth of plants in contaminated areas, as the recovering of crop fields or reforestation projects.

Hierarchical Nano/Micro Moth Eyelike Polymer Film Using Solid/Liquid Interfacial Reaction at Room Temperature.

A simple pathway for the fabrication of real moth eyelike patterned (MEP) polymer film with a double-layered nano/microhierarchical structure is demonstrated through a solid/liquid interfacial reaction at atmospheric conditions. A convex-structured polyvinyl alcohol (PVA) film containing CdCl2 was first fabricated using a self-organized honeycomb-patterned porous film as a template. The CdCl2/PVA convex film was immersed into Na2S/ethanol solution to facilitate the reaction between CdCl2 and Na2S at the solid/liquid interface, which led to the functionalization of CdS nanoparticles in the convex-structured PVA film. The tunable introduction of interfacial reaction resulted in the formation of a CdS moth eyelike nanoarray on the top surface of the PVA convex microarray, which mimicked the real moth eye (PVA-CdS MEP). PVA-CdS MEP film with a double moth eyelike structure showed improved antireflective property in comparison with flat and convex-structured PVA films. The PVA-CdS MEP film showed photoresponse under simulated solar light radiation and flexible duration after 500 cycles of folding.

Phytochemical characterization of the Ziziphus joazeiro Mart. metabolites by UPLC-QTOF and antifungal activity evaluation.

The aim of this study was to evaluate the antifungal and modulatory potential of the Ziziphus joazeiro bark and leaf extracts, both in isolation and in association with fluconazole, against resistant species from the Candida genus. Antifungal assays were used to determine the half maximal inhibitory concentration (IC50) of the extract in isolation and in combination with fluconazole using the broth microdilution method and spectrophotometric readings, followed by verification of the minimum fungicidal concentration by solid medium subculture. According to the cell viability curve, both extracts inhibited fungal growth in a concentration dependent manner, in addition to showing inhibitory concentrations similar to fluconazole. However, the extracts behaved in a fungistatic manner with minimum inhibitory concentration > 8.19 mg/mL and IC50 values ranging from 0.450 mg/mL to 9 mg/mL. The minimum inhibitory concentration for both extracts decreased when in combination with fluconazole, with the AEL standing out against Candida albicans URM 4387, displaying an IC50 equal to that of fluconazole (0.002 mg/mL). Nevertheless, fluconazole antagonism was observed against the tested strains. Overall, the evaluation of both extracts against Candida spp. presented inhibitory concentration values greater than fluconazole. Moreover, despite these being chemically complex crude extracts, they did demonstrate antifungal effects and properties that concur with their ethno-biological aspect.

Preoperative evaluation of mammographic microcalcifications after neoadjuvant chemotherapy for breast cancer.

AIM: To assess the predictive value of preoperative residual mammographic microcalcifications for residual tumours after neoadjuvant chemotherapy (NAC) for breast cancer. MATERIALS AND METHODS: This single-centre retrospective study included breast cancer patients who underwent NAC and demonstrated suspicious microcalcifications within or near the tumour bed on mammography from June 2015 to August 2018. The residual microcalcifications and remnant lesion on magnetic resonance imaging (MRI) were correlated with histopathological findings of residual tumours and immunohistochemical markers. RESULTS: A total of 96 patients were included. Ten patients achieved pathological complete response (pCR) and previous suspicious microcalcifications were associated with benign pathology in 10.4% (10/96) of the patients. In the remaining 86 patients who did not achieve pCR, 61.5% (59/96) of the residual microcalcifications were associated with invasive or in situ carcinoma and 28.1% (27/96) with benign pathology. Hormone receptor-positive (HR+) patients had the highest proportion of residual malignant microcalcifications compared to HR- patients (48.9% versus 13.5%, respectively; p=0.019). MRI correlated better than residual microcalcifications on mammography in predicting residual tumour extent in all subtypes (ICC=0.709 versus 0.365). MRI also showed higher correlation with residual tumour size for the HR-/HER2+ and HR-/HER2- subtype (ICC=0.925 and 0.876, respectively). CONCLUSION: The extent of microcalcifications on mammography after NAC did not correlate with the extent of residual cancer in 38.5% of women. Regardless of the extent of microcalcifications, residual tumour extent on MRI after NAC and molecular subtype could be an accurate tool in evaluating residual cancer after NAC.

Artemisia annua L. and photoresponse: from artemisinin accumulation, volatile profile and anatomical modifications to gene expression.

KEY MESSAGE: Blue and yellow light affected metabolism and the morphology. Blue and red promote the DOXP/MEP pathway. ADS gene expression was increased in plants cultivated under blue, promoting artemisinin content. Artemisinin-based combination therapies are the most effective treatment for highly lethal malaria. Artemisinin is produced in small quantities in the glandular trichomes of Artemisia annua L. Our aim was to evaluate the effect of light quality in A. annua cultivated in vitro under different light qualities, considering anatomical and morphological changes, the volatile composition, artemisinin content and the expression of two key enzymes for artemisinin biosynthesis. Yellow light is related to the increase in the number of glandular trichomes and this seemed to positively affect the molecular diversity in A. annua. Yellow light-stimulated glandular trichome frequency without triggered area enhancement, whereas blue light stimulated both parameters. Blue light enhanced the thickness of the leaf epidermis. The B-promoting effect was due to increased cell size and not to increased cell numbers. Green and yellow light positively influenced the volatile diversity in the plantlets. Nevertheless, blue and red light seemed to promote the DOXP/MEP pathway, while red light stimulates MVA pathway. Amorpha-4,11-diene synthase gene expression was significantly increased in plants cultivated under blue light, and not red light, promoting artemisinin content. Our results showed that light quality, more specifically blue and yellow light, positively affected secondary metabolism and the morphology of plantlets. It seemed that steps prior to the last one in the artemisinin biosynthesis pathway could be strongly influenced by blue light. Our work provides an alternative method to increase the amount of artemisinin production in A. annua without the use of transgenic plants, by the employment of blue light.

The influence of preoperative epidural labor analgesia on postoperative pain in parturients undergoing emergency cesarean section : A retrospective analysis.

BACKGROUND: Intense noxious input from the periphery may result in central sensitization and hyperexcitability, thus accentuating subsequent postoperative pain. Parturients who undergo emergency cesarean section (C-sec) after experiencing labor pain often develop labor pain-induced sensitization. OBJECTIVE: This retrospective study evaluated whether parturients without epidural labor analgesia (ELA) who underwent emergency C­sec, experienced more severe postoperative pain and required more rescue analgesics during the postoperative period. METHODS: The institution's medical database was searched for parturients who underwent emergency C­sec under spinal anesthesia for any reason between January 2013 and December 2016. Those who underwent elective C­sec under spinal anesthesia were included as the reference arm. Parturients were divided into three groups: ELA, no-ELA and elective. Characteristics of patients and perioperative outcomes were evaluated. As primary outcomes, numerical rating scale (NRS) for postoperative pain (0-10) was recorded up to 96 h postoperatively, and use of rescue analgesics was evaluated at 6, 24, and 48 h postoperatively. RESULTS: In the ELA, no-ELA, and elective groups, 61, 73, and 88 parturients, respectively, were ultimately enrolled. The NRS for pain were similar among the three groups, except at 6 h postoperatively. Parturients in the no-ELA group demonstrated significantly higher NRS at 6 h postoperatively than those in the ELA group (P = 0.01).More patients in the no-ELA group required rescue analgesics than in the ELA (P = 0.001) and elective groups (P < 0.001) at 6-24 h postoperatively. Moreover, the proportion of patients requiring rescue analgesics ≥2 times was also significantly higher in the no-ELA group (vs. the ELA group, P = 0.004; vs. the elective group, P < 0.001). CONCLUSION: Parturients undergoing emergency C­sec without ELA management during labor experienced greater postoperative pain and a greater use of rescue analgesics during the postoperative period. The findings suggest that administration of ELA before emergency C­sec may act as pre-emptive analgesia against postoperative pain.

Divergence of cryptic species of Doryteuthis plei Blainville, 1823 (Loliginidae, Cephalopoda) in the Western Atlantic Ocean is associated with the formation of the Caribbean Sea.

Although recent years have seen an increase in genetic analyses that identify new species of cephalopods and phylogeographic patterns, the loliginid squid of South America remain one of the least studied groups. The suggestion that Doryteuthis plei may represent distinct lineages within its extensive distribution along the western Atlantic coasts from Cape Hatteras, USA (36°N) to northern Argentina (35°S) is consistent with significant variation in a number of environmental variables along this range including in both temperature and salinity. In the present study D. plei samples were obtained from a large number of localities along the western Atlantic coasts to investigate the distribution of these possible species in a phylogeographic context. Phylogeographic analyses were performed using the mitochondrial Cytochrome Oxidase I gene and nuclear Rhodopsin gene. Divergence times were estimated using Bayesian strict clock dating with calibrations based on fossil records for divergence from the lineage containing Vampyroteuthis infernalis (162mya), the probable origins of the North American loliginids (45mya), and the European loliginids (20mya) and fossil statolith from Doryteuthis opalescens (3mya). Our results suggest a deep genetic divergence within Doryteuthis plei. The currently described specie consists of two genetically distinct clades (pair-wise genetic divergence of between 7.7 and 9.1%). One clade composed of individuals collected in northwestern Atlantic and Central Caribbean Atlantic waters and the other from southwestern Atlantic waters. The divergence time and sampling locations suggest the speciation process at approximately 16Mya, which is in full agreement with the middle Miocene orogeny of the Caribbean plate, ending up with the formation of the Lesser Antilles and the adjacent subduction zone, coinciding with a particularly low global sea level, resulting in the practical absence of continental shelves at the area, and therefore an effective geographic barrier for D. plei. Furthermore, this study also provides evidence of previously undocumented sub-population structuring in the Gulf of Mexico.

Anomalous Thermal Conductivity and Magnetic Torque Response in the Honeycomb Magnet α-RuCl_{3}.

We report on the unusual behavior of the in-plane thermal conductivity κ and torque τ response in the Kitaev-Heisenberg material α-RuCl_{3}. κ shows a striking enhancement with linear growth beyond H=7 T, where magnetic order disappears, while τ for both of the in-plane symmetry directions shows an anomaly at the same field. The temperature and field dependence of κ are far more complex than conventional phonon and magnon contributions, and require us to invoke the presence of unconventional spin excitations whose properties are characteristic of a field-induced spin-liquid phase related to the enigmatic physics of the Kitaev model in an applied magnetic field.

Magnetic Excitations and Continuum of a Possibly Field-Induced Quantum Spin Liquid in α-RuCl_{3}.

We report on terahertz spectroscopy of quantum spin dynamics in α-RuCl_{3}, a system proximate to the Kitaev honeycomb model, as a function of temperature and magnetic field. We follow the evolution of an extended magnetic continuum below the structural phase transition at T_{s2}=62 K. With the onset of a long-range magnetic order at T_{N}=6.5 K, spectral weight is transferred to a well-defined magnetic excitation at ℏω_{1}=2.48 meV, which is accompanied by a higher-energy band at ℏω_{2}=6.48 meV. Both excitations soften in a magnetic field, signaling a quantum phase transition close to B_{c}=7 T, where a broad continuum dominates the dynamical response. Above B_{c}, the long-range order is suppressed, and on top of the continuum, emergent magnetic excitations evolve. These excitations follow clear selection rules and exhibit distinct field dependencies, characterizing the dynamical properties of a possibly field-induced quantum spin liquid.

Evidence for a Field-Induced Quantum Spin Liquid in α-RuCl_{3}.

We report a ^{35}Cl nuclear magnetic resonance study in the honeycomb lattice α-RuCl_{3}, a material that has been suggested to potentially realize a Kitaev quantum spin liquid (QSL) ground state. Our results provide direct evidence that α-RuCl_{3} exhibits a magnetic-field-induced QSL. For fields larger than ∼10 T, a spin gap opens up while resonance lines remain sharp, evidencing that spins are quantum disordered and locally fluctuating. The spin gap increases linearly with an increasing magnetic field, reaching ∼50 K at 15 T, and is nearly isotropic with respect to the field direction. The unusual rapid increase of the spin gap with increasing field and its isotropic nature are incompatible with conventional magnetic ordering and, in particular, exclude that the ground state is a fully polarized ferromagnet. The presence of such a field-induced gapped QSL phase has indeed been predicted in the Kitaev model.

Tannic acid affects the phenotype of Staphylococcus aureus resistant to tetracycline and erythromycin by inhibition of efflux pumps.

The widespread use of antibiotics created selective pressure for the emergence of strains that would persist despite antibiotic toxicity. The bacterial resistance mechanisms are several, with efflux pumps being one of the main ones. These pumps are membrane proteins with the function of removing antibiotics from the cell cytoplasm. Due to this importance, the aim of this work was to evaluate the inhibitory effect of tannic acid against efflux pumps expressed by the Staphylococcus aureus RN4220 and IS-58 strains. The efflux pump inhibition was assayed using a sub-inhibitory concentration of efflux pump standard inhibitors and tannic acid (MIC/8), observing their capacity to decrease the MIC of Ethidium bromide (EtBr) and antibiotics due the possible inhibitory effect of these substances. The MICs of EtBr and antibiotics were significantly different in the presence of tannic acid, indicating the inhibitory effect of this product against efflux pumps of both strains. These results indicate the possible usage of tannic acid asan inhibitor and an adjuvant in the antibiotic therapy against multidrug resistant bacteria (MDR).

Evaluation of the tannic acid inhibitory effect against the NorA efflux pump of Staphylococcus aureus.

During the early periods of antibiotic usage, bacterial infections were considered tamed. However, widespread antibiotic use has promoted the emergence of antibiotic-resistant pathogens, including multidrug resistant strains. Active efflux is a mechanism for bacterial resistance to inhibitory substances, known simply as drug efflux pumps. The bacterium Staphylococcus aureus is an important pathogenic bacterium responsible for an array of infections. The NorA efflux pump has been shown to be responsible for moderate fluoroquinolone resistance of S. aureus. The inhibition of the efflux pump was assayed using a sub-inhibitory concentration of standard efflux pump inhibitors and tannic acid (MIC/8), where its capacity to decrease the MIC of Ethidium bromide (EtBr) and antibiotics due to the possible inhibitory effect of these substances was observed. The MICs of EtBr and antibiotics were significantly reduced in the presence of tannic acid, indicating the inhibitory effect of this agent against the efflux pumps of both strains causing a three-fold reduction of the MIC when compared with the control. These results indicate the possible usage of tannic acid as an adjuvant in antibiotic therapy against multidrug resistant bacteria (MDR).

Magnesium sulphate attenuates acute postoperative pain and increased pain intensity after surgical injury in staged bilateral total knee arthroplasty: a randomized, double-blinded, placebo-controlled trial.

BACKGROUND: We evaluated the effect of magnesium sulphate on increased pain in 44 patients undergoing staged bilateral total knee arthroplasty (TKA). METHODS: The magnesium group (n=22) and the control group (n=22) received magnesium sulphate and isotonic saline, respectively, throughout the surgery. Postoperative pain (visual analogue scale, VAS) at rest and the amounts of patient-controlled analgesia (PCA, fentanyl) and rescue analgesia (ketoprofen) administered during the first 48 h were compared between the two groups and within each group between the first and second TKA. RESULTS: The VAS scores were significantly higher in the control group than in the magnesium group not only after the first TKA [29 (11) vs 19 (9) at 24 h and 33 (8) vs 24 (10) at 48 h; P=0.001] but also after the second TKA [44 (17) vs 20 (10) at 24 h and 43 (14) vs 25 (10) at 48 h; P<0.001]. In the control group, VAS scores were significantly higher for the second than for the first operated knee [44 (17) vs 29 (11) at 24 h and 43 (14) vs 33 (8) at 48 h; P<0.001 and P=0.006, respectively]. In the magnesium group, there were no significant differences in VAS scores between the first and second TKA. Magnesium significantly reduced the amounts of rescue analgesics and fentanyl administered over the first 48 h postoperatively. CONCLUSIONS: Magnesium sulphate administration significantly reduced postoperative pain and minimized the difference in pain intensity between the first and second operations. CLINICAL TRIAL REGISTRATION: KCT0001361.

Prospective, randomized and controlled trial on magnesium sulfate administration during laparoscopic gastrectomy: effects on surgical space conditions and recovery profiles.

BACKGROUND: The degree of neuromuscular blockade is one of the important factors that determine the condition of surgical space during laparoscopic surgery. Magnesium sulfate potentiates the actions of neuromuscular blocking agent, and we hypothesized that intraoperative magnesium sulfate infusion may improve surgical space condition during laparoscopic surgery. METHODS: Eighty-four patients undergoing elective laparoscopic gastrectomy were randomized to receive isotonic saline (group C) or magnesium sulfate (group M, loading dose with 50 mg/kg over 10 min and then 15 mg/kg/h by continuous infusion) to maintain the moderate neuromuscular blockade using rocuronium. Two experienced surgeons scored the quality of surgical space condition using a 5-point surgical rating scale (SRS). The secondary outcomes included recovery profiles, postoperative pain and adverse events. RESULTS: The SRS in group M was higher than that of group C. The proportion of patients with a SRS of 5 (optimal) was 2.7 % in the group C and 40.5 % in the group M (P < 0.0001) although a lower amount of rocuronium was required in group M than group C [24.2 (6.5) mg/h for group M vs. 27.5 (6) mg/h for group C; P = 0.017]. Pain after operation site was less severe in group M than in group C at postoperative 24 h (P = 0.009). Recovery profiles and adverse events were similar between the two groups. CONCLUSION: Intraoperative administration of magnesium sulfate improved the quality of surgical space conditions and decreased neuromuscular blocking agent requirement and postoperative pain in patients undergoing laparoscopic gastrectomy.

The effect of tranexamic acid on blood coagulation in total hip replacement arthroplasty: rotational thromboelastographic (ROTEM®) analysis.

We evaluated changes in rotational thromboelastometry (ROTEM(®) ) parameters and clinical outcomes in patients undergoing total hip replacement arthroplasty, with concomitant infusions of tranexamic acid and of 6% hydroxyethyl starch 130/0.4. Fifty-five patients were randomly assigned to either the tranexamic acid (n = 29) or the control (n = 26) group. Hydroxyethyl starch was administered in the range of 10-15 ml.kg(-1) during the operation in both groups. In the control group, the clot formation time and maximum clot firmness of APTEM showed significant differences when compared with those of EXTEM at one hour postoperatively, suggestive of fibrinolysis. In the tranexamic acid group, there was no significant difference between each postoperative EXTEM and APTEM parameter. In the tranexamic acid and control group, postoperative blood loss was 308 ml (210-420 [106-745]) and 488 ml (375-620 [170-910], p = 0.002), respectively, and total blood loss was 1168 ml (922-1470 [663-2107]) and 1563 ml (1276-1708 [887-1494], p = 0.003). Haemoglobin concentration was higher in the tranexamic acid group on the second postoperative day (10.5 (9.4-12.1 [7.9-14.0]) vs. 9.6 (8.9-10.5[7.3-16.0]) g.dl(-1) , p = 0.027). In patients undergoing total hip replacement arthroplasty, postoperative fibrinolysis aggravated by hydroxyethyl starch was attenuated by co-administration of 10 mg.kg(-1) tranexamic acid, which may have led to less postoperative blood loss.

The effects of acute normovolaemic haemodilution on peri-operative coagulation in total hip arthroplasty.

Total hip arthroplasty results in substantial blood loss in the peri-operative period. We evaluated the effects of acute normovolaemic haemodilution on blood coagulation and platelet function in 11 patients undergoing total hip arthroplasty. We performed acute normovolaemic haemodilution and haematological tests, rotational thromboelastometry (ROTEM(®) ) and whole-blood impedance aggregometry. Blood samples were obtained at three time points: (i) before the initiation of acute normovolaemic haemodilution; (ii) 20 min after completion of acute normovolaemic haemodilution; and (iii) 20 min after retransfusion. After acute normovolaemic haemodilution, ROTEM parameters demonstrated hypocoagulability. Clot formation time of INTEM was increased by 31.6% (p = 0.016), whereas the α-angle and maximum clot formation of INTEM decreased by 8.1% (p = 0.032) and 3.0% (p = 0.013) respectively, compared with baseline values. Clotting time and clot formation time of EXTEM were increased by 40.8% (p = 0.042) and 31.3% (p = 0.016), respectively, whereas the α-angle and maximum clot formation of EXTEM were decreased by 11.9% (p = 0.020) and 9.5% (p = 0.013), respectively. The maximum clot formation of FIBTEM decreased by 35.1% compared with the baseline value (p = 0.007). Following retransfusion, ROTEM values returned to baseline; clot formation time decreased and the α-angle and maximum clot formation increased. There were no significant changes in platelet aggregation during the study. At 20 min after the end of acute normovolaemic haemodilution, the international normalised ratio of prothrombin time was increased compared with the baseline value (p = 0.003). We conclude that acute normovolaemic haemodilution resulted in a hypocoagulable state compared with baseline values and that coagulation parameters returned to normal after retransfusion.