Anaesthesia in a parturient with systemic mastocytosis.

Mastocytosis is characterized by clonal expansion of mast cells, with abnormal accumulation in different organs. Perioperatively, numerous stimuli may lead to the release of vasoactive substances by mast cells. Parturients with systemic mastocytosis pose a challenge to the anesthesiologist: on one hand, the pain and stress of labor may lead to greater mast cell activation and, on the other, the administration of drugs that may possibly trigger the release of mast cell mediators. The authors describe a case of a 34-year-old pregnant woman with systemic mastocytosis who requests labor analgesia. An epidural analgesia was performed after induction of labor, after considering anesthetic particularities. The epidural procedure, labor and delivery were uneventful. A review of systemic mastocytosis is provided and its anesthetic considerations are discussed.

Consideraciones anestésicas en una parturienta con mastocitosis sistémica / Anesthetic considerations in a laboring woman with systemic mastocytosis

La mastocitosis se caracteriza por la expansión clónica de mastocitos, con acumulación anormal en diferentes órganos. Perioperatoriamente, numerosos estímulos pueden originar la liberación de sustancias vasoactivas por parte de los mastocitos. Las parturientas con mastocitosis sistémica plantean una dificultad al anestesiólogo: por un lado, el dolor y el estrés del parto pueden causar una mayor activación de los mastocitos y, por otro, la administración de fármacos puede desencadenar posiblemente la liberación de mediadores de los mastocitos. Los autores describen un caso de una embarazada de 34 años de edad con mastocitosis sistémica que solicita analgesia para el parto. Se realizó analgesia epidural tras la inducción del parto, una vez consideradas las particularidades anestésicas. El procedimiento epidural, el parto y la expulsión transcurrieron sin incidentes. Se aporta una revisión de la mastocitosis sistémica y se abordan sus consideraciones anestésicas.(AU)

Mastocytosis is characterized by clonal expansion of mast cells, with abnormal accumulation in different organs. Perioperatively, numerous stimuli may lead to the release of vasoactive substances by mast cells. Parturients with systemic mastocytosis pose a challenge to the anesthesiologist: on one hand, the pain and stress of labor may lead to greater mast cell activation and, on the other, the administration of drugs that may possibly trigger the release of mast cell mediators. The authors describe a case of a 34-year-old pregnant woman with systemic mastocytosis who requests labor analgesia. An epidural analgesia was performed after induction of labor, after considering anesthetic particularities. The epidural procedure, labor and delivery were uneventful. A review of systemic mastocytosis is provided and its anesthetic considerations are discussed.(AU)

Anesthetic considerations in a laboring woman with systemic mastocytosis. / Consideraciones anestésicas en una parturienta con mastocitosis sistémica.

Mastocytosis is characterized by clonal expansion of mast cells, with abnormal accumulation in different organs. Perioperatively, numerous stimuli may lead to the release of vasoactive substances by mast cells. Parturients with systemic mastocytosis pose a challenge to the anesthesiologist: on one hand, the pain and stress of labor may lead to greater mast cell activation and, on the other, the administration of drugs that may possibly trigger the release of mast cell mediators. The authors describe a case of a 34-year-old pregnant woman with systemic mastocytosis who requests labor analgesia. An epidural analgesia was performed after induction of labor, after considering anesthetic particularities. The epidural procedure, labor and delivery were uneventful. A review of systemic mastocytosis is provided and its anesthetic considerations are discussed.

A method to assess heart rate variability in neonate rats: validation in normotensive and hypertensive animals.

Several studies have focused on the heart rate variability (HRV) of murine species, while studies discussing HRV in murine neonates and infants remain scarce, since recording hemodynamic signals through invasive methods in small animals has been found to be quite challenging. Thus, this study aimed at describing and validating a novel method to assess HRV in newborn rats. An electrocardiogram (ECG) system was used to determine RR intervals in awake newborns and evaluate HRV in normotensive (Wistar) and hypertensive (SHR) neonate rats. After birth, ECG was recorded in the awake newborns, and they were allowed to rest on a heated surface, restricted only by the weight of the adhesive ECG electrodes. The electrodes were cut and adapted to provide more comfort to the animal, and gently placed on the newborn's skin. RR intervals were recorded over a 30-min period using an ECG system together with LabChart software (4 KHz). Three sequences of 5 min each from the ECG recording period were analyzed in time and frequency domains, using CardioSeries software. ECG data resulted in a clearly interpretable signal that was used to generate an RR interval sequence through time for the analysis of HRV. SHR neonates presented increased cardiac sympathovagal balance compared to Wistar neonates (low frequency/high frequency: 3.85±0.71 vs 0.90±0.09). In conclusion, the ECG setup here described may be used to record RR intervals to assess HRV in neonate rats, thus detecting early impairment of HRV in hypertensive newborns.

A method to assess heart rate variability in neonate rats: validation in normotensive and hypertensive animals

Several studies have focused on the heart rate variability (HRV) of murine species, while studies discussing HRV in murine neonates and infants remain scarce, since recording hemodynamic signals through invasive methods in small animals has been found to be quite challenging. Thus, this study aimed at describing and validating a novel method to assess HRV in newborn rats. An electrocardiogram (ECG) system was used to determine RR intervals in awake newborns and evaluate HRV in normotensive (Wistar) and hypertensive (SHR) neonate rats. After birth, ECG was recorded in the awake newborns, and they were allowed to rest on a heated surface, restricted only by the weight of the adhesive ECG electrodes. The electrodes were cut and adapted to provide more comfort to the animal, and gently placed on the newborn's skin. RR intervals were recorded over a 30-min period using an ECG system together with LabChart software (4 KHz). Three sequences of 5 min each from the ECG recording period were analyzed in time and frequency domains, using CardioSeries software. ECG data resulted in a clearly interpretable signal that was used to generate an RR interval sequence through time for the analysis of HRV. SHR neonates presented increased cardiac sympathovagal balance compared to Wistar neonates (low frequency/high frequency: 3.85±0.71 vs 0.90±0.09). In conclusion, the ECG setup here described may be used to record RR intervals to assess HRV in neonate rats, thus detecting early impairment of HRV in hypertensive newborns.

Lipid core nanoparticles resembling low-density lipoprotein and regression of atherosclerotic lesions: effects of particle size.

Particles are usually polydispersed and size is an important feature for lipid-based drug delivery systems in order to optimize cell-particle interactions as to pharmacologic action and toxicity. Lipid nanoparticles (LDE) with composition similar to that of low-density lipoprotein carrying paclitaxel were shown to markedly reduce atherosclerosis lesions induced in rabbits by cholesterol feeding. The aim of this study was to test whether two LDE fractions, one with small (20-60 nm) and the other with large (60-100 nm) particles, had different actions on the atherosclerotic lesions. The two LDE-paclitaxel fractions, prepared by microfluidization, were separated by density gradient ultracentrifugation and injected (4 mg/body weight, intravenously once a week) into two groups of rabbits previously fed cholesterol for 4 weeks. A group of cholesterol-fed animals injected with saline solution was used as control to assess lesion reduction with treatment. After the treatment period, the animals were euthanized for analysis. After treatment, both the small and large nanoparticle preparations of LDE-paclitaxel had equally strong anti-atherosclerosis action. Both reduced lesion extension in the aorta by roughly 50%, decreased the intima width by 75% and the macrophage presence in the intima by 50%. The two preparations also showed similar toxicity profile. In conclusion, within the 20-100 nm range, size is apparently not an important feature regarding the LDE nanoparticle system and perhaps other solid lipid-based systems.

Bioengineered surfaces to improve the blood compatibility of biomaterials through direct thrombin inactivation.

Thrombus formation, due to thrombin generation, is a major problem affecting blood-contacting medical devices. This work aimed to develop a new strategy to improve the hemocompatibility of such devices by the immobilization of a naturally occurring thrombin inhibitor into a nanostructured surface. Boophilin, a direct thrombin inhibitor from the cattle tick Rhipicephalus microplus, was produced as a recombinant protein in Pichia pastoris. Boophilin was biotinylated and immobilized on biotin-terminated self-assembled monolayers (SAM) via neutravidin. In order to maintain its proteinase inhibitory capacity after surface immobilization, boophilin was biotinylated after the formation of a boophilin-thrombin complex to minimize the biotinylation of the residues involved in thrombin-boophilin interaction. The extent of boophilin biotinylation was determined using matrix-assisted laser desorption/ionization-time of flight/time of flight mass spectrometry. Boophilin immobilization and thrombin adsorption were quantified using quartz crystal microbalance with dissipation. Thrombin competitive adsorption from human serum was assessed using ¹²5I-thrombin. Thrombin inhibition and plasma clotting time were determined using spectrophotometric techniques. Boophilin-coated SAM were able to promote thrombin adsorption in a selective way, inhibiting most of its activity and delaying plasma coagulation in comparison with boophilin-free surfaces, demonstrating boophilin's potential to improve the hemocompatibility of biomaterials used in the production of blood-contacting devices.