Experimental research with synthetic copolymer-coated cardiopulmonary bypass circuits: inflammatory and thrombogenicity analysis

This study aimed to assess complement system activation and index of thrombogenicity and platelet aggregation between synthetic copolymer-coated cardiopulmonary bypass (CPB) circuit and conventional CPB circuit. Twenty-six pigs were equally divided into two groups--the conventional group and the coated group. They were placed on CPB for 90 min, and blood samples were collected at three different time points (T0, right before CPB establishment; T1, 45 min after starting CPB; and T2, 90 min after starting CPB) to measure total count of inflammatory cells (leukocytes, neutrophils, lymphocytes, and platelets) and serum levels of fraction C3 of complement system. Upon completion of the 90-min CPB, fragments of different compartments of the CPB circuit were taken for assessing index of thrombogenicity and platelet aggregation. There were no differences between both groups regarding total count of leukocytes, neutrophils, and lymphocytes; however, there was a lower count of platelets at T2 in the coated group (P = 0.020). The serum level of fraction C3 was lower in the coated group at T1 (P = 0.020) and T2 (P = 0.017). Higher index of thrombogenicity and platelet aggregation were detected in the conventional group (77% of the animals within the conventional group) than in the coated group (46% of the animals within the coated group). In conclusion, in heart surgery requiring CPB, the use of synthetic copolymer-coated CPB circuit may be useful to reduce complement system activation, as well as attenuating index of thrombogenicity and platelet aggregation.     

Impact of genetic polymorphisms on tacrolimus pharmacokinetics and the clinical outcome of renal transplantation

We retrospectively examined the association of polymorphisms in the CYP3A, CYP2J2, CYP2C8, and ABCB1 genes with pharmacokinetic (PKs) and pharmacodynamic (PDs) parameters of tacrolimus in 103 renal transplant recipients for a period of 1 year. CYP3A5 expressers had lower predose concentrations (C(0) )/dose and higher dose requirements than nonexpressers throughout the study. Among CYP3A5*1 carriers, those also carrying the CYP3A4*1B allele showed the lowest C(0) /dose, as compared with CYP3A4*1/CYP3A5*3 carriers (54.28±26.45, 59.12±24.00, 62.43±41.12, and 57.01±17.34 vs. 112.37± 76.60, 123.21±59.57, 163.34±76.23, and 183.07±107.82 at 1 week, 1 month, 5 months, and 1 year after transplantation). In addition, CYP3A4*1B/CYP3A5*1 carriers showed significantly lower dose-corrected exposure than CYP3A4*1/CYP3A5*1 carriers 1 year after transplantation (57.01±17.34 vs. 100.09±24.78; P=0.016). Only the ABCB1 TGC (3435-2677-1236) haplotype showed a consistent association with PDs (nephrotoxicity; OR=4.73; CI: 1.3-16.7; P=0.02). Our findings indicate that the CYP3A4*1B-CYP3A5*1 haplotype may have a more profound impact in tacrolimus PKs than the CYP3A5*1 allele. This study does not support a critical role of the CYP450 or ABCB1 single nucleotide polymorphisms in the occurrence of toxicity or acute rejection in renal transplant recipients treated with tacrolimus.     

Posterior approach (Kraske procedure) for surgical treatment of presacral tumors

Presacral tumors are rare,but can comprise a great variety of histological types.Congenital tumors are the most common.Once the diagnosis is established,surgical resection is essential because of the potential for malignancy or infection.Previous biopsy is not necessary or may be even harmful.To decide the best surgical approach(abdominal,sacral or combined) an individual and multidisciplinary analysis must be carried out.We report three cases of cystic presacral masses in which a posterior approach(Kraske procedure) enabled complete resection,the only way to decrease local recurrence.All patients had a satisfactory recovery.A brief overview of retrorectal tumors is presented,focusing on classification,clinical presentation,diagnosis and surgical management.     

Electrocortical Analysis of Patients with Intercostobrachial Pain Treated with TENS after Breast Cancer Surgery

[Purpose] Among the physical therapeutic procedures to decrease pain, there is transcutaneous electrical neural stimulation (TENS). There is no consensus about its efficacy for oncological patients, especially for post-mastectomy pain and eletrocortical changes in somatosensory areas. The aim of this study was to analyze acute electrocortical changes after TENS treatment of patients with intercostobrachial post mastectomy pain. [Subjects] Eighteen patients were divided into acupuncture (A) and burst (B) group. [Methods] In this pre and post-intervention study each group was measured for EEG analysis in absulte power in alpha band (8–14 Hz). Outcomes variables were the alpha waveband in the sensorymotor cortex and pain pre-and-post TENS intervention. Data were analyzed using ANOVA to compare times (rest, 10 and 15 min), group and electrodes. Pain was analyzed using percentual pain evaluation (PPE) in both groups. [Results] Outcomes indicate main effects of time and electrodes because of slow (8–10 Hz) and fast alpha (10–12 Hz) wavebands decreased. PPE reduced 88.4% in A and 66.3% in G. [Conclusion] TENS promoted electrical modification in the parietal region and a decrease in pain. Future studies should investigate other wave must be proposed for other bands and use different methods of EEG analysis to elucidate the actual mechanisms behind the efficacy of TENS treatment.Key words: Transcutaneous electric nerve stimulation, Mastectomy, Electroencephalography     

Ventricular–arterial coupling: Invasive and non-invasive assessment

Interactions between the left ventricle (LV) and the arterial system, (ventricular–arterial coupling) are key determinants of cardiovascular function. Ventricular–arterial coupling is most frequently assessed in the pressure–volume plane using the ratio of effective arterial elastance (E_A) to LV end-systolic elastance (E_ES). E_A (usually interpreted as a lumped index of arterial load) can be computed as end-systolic pressure/stroke volume, whereas E_ES (a load-independent measure of LV chamber systolic stiffness and contractility) is ideally assessed invasively using data from a family of pressure–volume loops obtained during an acute preload alteration. Single-beat methods have also been proposed, allowing for non-invasive estimations of E_ES using simple echocardiographic measurements. The E_A/E_ES ratio is useful because it provides information regarding the operating mechanical efficiency and performance of the ventricular–arterial system. However, it should be recognized that analyses in the pressure–volume plane have several limitations and that “ventricular–arterial coupling” encompasses multiple physiologic aspects, many of which are not captured in the pressure–volume plane. Therefore, additional assessments provide important incremental physiologic information about the cardiovascular system and should be more widely used. In particular, it should be recognized that: (1) comprehensive analyses of arterial load are important because E_A poorly characterizes pulsatile LV load and does not depend exclusively on arterial properties; (2) The systolic loading sequence, an important aspect of ventricular–arterial coupling, is neglected by pressure–volume analyses, and can profoundly impact LV function, remodeling and progression to heart failure. This brief review summarizes methods for the assessment of ventricular–arterial interactions, as discussed at the Artery 12 meeting (October 2012).