Impacto tardio da hipertensão pulmonar e da insuficiência tricúspide após troca transcateter de valva aórtica / Late impact of pulmonary hypertension and tricuspid regurgitation after transcatheter aortic valve replacement

INTRODUÇÃO: Troca transcateter de valva aórtica (TAVR) é cada vez mais utilizada no tratamento da estenose aórtica (EA) senil. EA é comumente associada a hipertensão pulmonar (HP) e insuficiência tricúspide (IT). Nosso OBJETIVO foi avaliar o impacto tardio no curso da HP e IT. MÉTODOS: Pacientes submetidos a TAVR foram acompanhados quanto aos dados ecocardiográficos da HP e da IT por 24 meses. Todos os ecocardiogramas foram realizados em centro único. Foram divididos em grupos de acordo com IT e HP após 24 meses (pressão sistólica da artéria pulmonar = or < 45 mmHg) com follow-up de até 96 meses. Resultados clínicos e mortalidade foram comparados. RESULTADOS: 156 e 151 pacientes foram selecionados para acompanhamento da HP e da IT respectivamente. Média de follow-up foi de 42,23±17,53 meses e 42,60±17,67 meses para grupos de HP e IT. HP se reduziu após o TAVR (32,7% pre-TAVR vs. 20,5% pos-TAVR, p<0,001), mas não foi encontrada mudança significativa na IT (11,9% pre-TAVR vs. 10,6% pos-TAVR). Aumento de átrio esquerdo (AE) foi associado a manutenção de HP (p=0,002). Além disso, o aumento do diâmetro do AE (p=0,015) e EuroSCORE II elevado (p=0,041) foram correlacionados ao surgimento de nova HP. Na análise multivariada, surgimento de nova HP (HR 6,17, 95% CI 1,71­22,29,p=0,005), disfunção diastólica tipo II ou III (HR 1,06, 95% CI 1,06-1,11, p=0,036) e diâmetro de AE (HR 1,11, 95% CI 1,02­1,21, p=0,02) foram preditores independentes de mortalidade. CONCLUSÃO: TAVR foi capaz de reduzir a gravidade da HP, mas não da IT. Além disso, a sobrevida a longo prazo foi afetada pela HP, disfunção diastólica e tamanho do AE.

Long-term analysis of pulmonary hypertension and tricuspid regurgitation after transcatheter aortic valve replacement

INTRODUCTION: transcatheter aortic valve replacement (TAVR) is increasingly utilized in treatment of aortic stenosis (AS). AS is commonly associated to pulmonary hypertension (PH) and tricuspid regurgitation (TR). We aimed to evaluate the long-term post-TAVR course of PH and TR. METHODS: Patients undergoing TAVR were screened for 24-month echocardiographic data on PH and TR. All echocardiograms were performed by a sing le team. Patients were divided in groups according to TR and PH (pulmonary systolic pressure ≥ or < 45 mmHg) grading at 24 months with follow-up of up to 96 months. Standardized clinical outcomes and survival were compared. RESULTS: 156 and 151 patients were se le cted for PH and TR follow-up, respectively. Mean follow-up was 42.23±17.53 months and 42.60±17.67 months for PH and TR groups. Maximum follow-up was 96 months. PH was reduced post-TAVR (32.7% pre-TAVR vs. 20.5% post-TAVR, p<0.001), but no significant difference in TR was found (11.9% pre-TAVR vs. 10.6% post-TAVR). Increased le ft atrial (LA) diameter (p = 0.002) was associated to maintenance PH. Moreover, increased LA diameter (p=0.015) and increased EuroSCORE II (p=0.041) were correlated to new onset PH. On a multivariab le Cox regression model, new onset PH (HR 6.17, 95% CI 1.71­22.29, p=0.005), diastolic dysfunction type II or III (HR 1.06, 95% CI 1.06-1.11, p=0.036) and LA diameter (HR 1.11, 95% CI 1.02­1.21, p=0.02) were independent predictors of long-term mortality. CONCLUSIONS: TAVR was ab le to reduce the severity of PH, but not TR, in this cohort. Additionally, long-term survival was affected by PH, diastolic dysfunction and LA sizing.

Purely-elastic flow instabilities and elastic turbulence in microfluidic cross-slot devices.

We experimentally investigate the dynamics of viscoelastic fluid flows in cross-slot microgeometries under creeping flow conditions. We focus on the unsteady flow regime observed at high Weissenberg numbers (Wi) with the purpose of understanding the underlying flow signature of elastic turbulence. The effects of the device aspect ratio and fluid rheology on the unsteady flow state are investigated. Visualization of the flow patterns and time-resolved micro-particle image velocimetry were carried out to study the fluid flow behavior for a wide range of Weissenberg numbers. A periodic flow behavior is observed at low Weissenberg numbers followed by a more complex dynamics as Wi increases, eventually leading to the onset of elastic turbulence for very high Weissenberg numbers.

Establishment of an anesthetic protocol for semen collection by electroejaculation in six-banded armadillos (Euphractus sexcinctus Linnaeus, 1758) / Estabelecimento de um protocolo anestésico para coleta de sêmen por eletroejaculação em tatus-peba (Euphractus sexcinctus Linnaeus, 1758)

The aim was to verify the effects of different anesthetic protocols used during electroejaculation (EEJ) in six-banded armadillos (Euphractus sexcinctus). Four sexually matured animals were physically restrained and subjected to semen collection by the EEJ following three treatments: The control group consisted of no use of anesthesia; in the others, the anesthetic combinations xylazine/ketamine/propofol or butorphanol/ ketamine/propofol were administered. For each group, twelve procedures were conducted for EEJ. Semen was evaluated for volume, color, aspect, motility, sperm concentration, morphology, viability, and functional membrane integrity. The highest efficiency (100% ejaculates) was achieved when the control group was used; the xylazine/ketamine/propofol association provided only 11 ejaculates from a total of 12 attempts (91.6% efficiency), while only 4 ejaculates (33% efficiency) were obtained with butorphanol/ketamine/propofol (P<0.05). Both protocols provided rapid induction and relaxation enough to perform the EEJ. In the use of butorphanol/ketamine/propofol, the animals recovered at 16.5±1.5min, a time shorter than in the use of xylazine/ketamine/propofol protocol, 20.7±1.0min (P>0.05). The semen volume and sperm concentration obtained in the use of xylazine/ketamine/propofol association were significantly higher than those verified for butorphanol/ketamine/propofol protocol. In conclusion, the xylazine/ketamine/propofol association is indicated for anesthesia of six-banded armadillos submitted to EEJ.(AU)

Objetivou-se verificar os efeitos de diferentes protocolos anestésicos usados durante a eletroejaculação (EEJ) em tatus-peba (Euphractus sexcinctus). Quatro animais sexualmente maduros foram contidos fisicamente e submetidos à coleta de sêmen por EEJ, seguindo três tratamentos: o grupo controle consistiu do não uso de anestesia; nos outros, foram administradas combinações anestésicas de xilazina/cetamina/propofol, ou butorfanol/cetamina/propofol. Para cada grupo, foram conduzidos 12 procedimentos de EEJ. O sêmen foi avaliado para volume, cor, aspecto, motilidade, concentração de espermatozoides, morfologia, viabilidade e integridade funcional da membrana. A mais alta eficiência (100% de ejaculados) foi alcançada quando o grupo controle foi utilizado; a associação de cetamina/xilazina/propofol forneceu apenas 11 ejaculados de um total de 12 tentativas (de eficiência 91,6%), enquanto apenas quatro ejaculados (eficiência de 33%) foram obtidos com butorfanol/cetamina/propofol (P<0,05). Ambos os protocolos forneceram rápida indução e relaxamento suficientes para executar a EEJ. Na utilização de butorfanol/cetamina/propofol, os animais se recuperaram em 16,5±1,5min, um tempo mais curto do que no uso de xilazina/cetamina/protocolo de propofol, 20,7±1,0min (P>0,05). O volume de sêmen e a concentração espermática obtidos no uso da associação xilazina/cetamina/propofol foram significativamente maiores do que os verificados para o protocolo butorfanol/cetamina/propofol. Em conclusão, a associação de cetamina/xilazina/propofol é indicada para anestesia de tatus-peba submetidos à EEJ.(AU)

Purely elastic flow instabilities in microscale cross-slot devices.

We present an experimental investigation of viscoelastic fluid flow in a cross-slot microgeometry under low Reynolds number flow conditions. By using several viscoelastic fluids, we investigate the effects of the microchannel bounding walls and the polymer solution concentration on the flow patterns. We demonstrate that for concentrated polymer solutions, the flow undergoes a bifurcation above a critical Weissenberg number (Wi) at which the flow becomes asymmetric but remains steady. The appearance of this elastic instability depends on the channel aspect ratio, defined as the ratio between the depth and the width of the channels. At high aspect ratios, when bounding wall effects are reduced, two types of elastic instabilities were observed, one in which the flow becomes asymmetric and steady, followed by a second instability at higher Wi, in which the flow becomes time-dependent. When the aspect ratio decreases, the bounding walls have a stabilizing effect, preventing the occurrence of steady asymmetric flow and postponing the transition to unsteady flow to higher Wi. For less concentrated solutions, the first elastic instability to steady asymmetric flow is absent and only the time-dependent flow instability is observed.

First-trimester maternal ophthalmic artery Doppler analysis for prediction of pre-eclampsia.

OBJECTIVE: To determine the performance of a multiparametric test comprising maternal risk factors, uterine artery Doppler and ophthalmic artery Doppler in the first trimester of pregnancy for the prediction of pre-eclampsia (PE). METHODS: This prospective observational cohort study recruited patients in the first trimester of pregnancy. Maternal uterine artery and ophthalmic artery Doppler assessments were performed in 440 singleton pregnancies at 11-14 weeks of gestation. Additional history was obtained through participant questionnaires, and follow-up occurred to discharge postdelivery. The normotensive and pre-eclamptic groups were compared using parametric (Student's t-test) and non-parametric (Mann-Whitney U-test) tests. Univariable and multivariable logistic regression analyses were performed to determine which biophysical factors, and which of the factors among the maternal characteristics and medical and obstetric history, had a significant contribution to the prediction of PE in a multiparametric model. RESULTS: Thirty-one (7%) patients developed PE, including nine (2%) who required delivery before 34 weeks (early PE) and 22 (5%) with late PE. There were statistically significant differences in uterine artery pulsatility index (UtA-PI) and ophthalmic artery first diastolic peak (PD1) mean values between the PE and control groups. In a multiparametric model, both UtA-PI and PD1 achieved a 67% detection rate for early PE, although when combined, the detection rate only increased to 68%. CONCLUSIONS: The efficiency of ophthalmic artery PD1 in the first trimester as a predictive marker for the later development of PE was approximately equal to that described for uterine artery Doppler. Although these findings do not support the replacement of uterine artery Doppler analysis in multiparametric predictive models for PE, they do provide novel insights into first-trimester maternal systemic vascular changes that precede the clinical development of this condition.

Protein profile of the seminal plasma of collared peccaries (Pecari tajacu Linnaeus, 1758).

This study was conducted to characterize the major proteins of the peccary seminal plasma, based on the semen samples collected from nine adult and reproductively sound animals. Our approach included the use of two-dimensional electrophoresis followed by Coomassie blue staining and analysis of polypeptide maps with PDQuest Software (Bio-Rad). Proteins were identified by tandem mass spectrometry (LC-MS/MS). We detected 179 protein spots per gel and 98 spots were identified by mass spectrometry, corresponding to 23 different proteins. The combined intensity of those spots accounted for 56.2±6% of the intensities of all spots and 60.9% of the intensities of spots presented in every protein map. Protein spots identified as clusterin represented 19.7±8.3% of the integrated optical densities of all spots detected in the seminal plasma maps. There was a negative association (r=-0.87; P<0.05) between the intensity of a clusterin spot and the percentage of sperm with functional membrane. Spermadhesin porcine seminal plasma protein 1 and bodhesin 2 comprised 5.4±1.9 and 8.8±3.9% of the total intensity of all spots respectively. Many proteins appeared in a polymorphic pattern, such as clusterin (27 spots), epididymal secretory glutathione peroxidase (ten spots), inter-α-trypsin inhibitor (12 spots), and IgG-binding protein (ten spots), among others. In conclusion, we presently describe the major seminal plasma proteome of the peccary, which exhibits a distinct high expression of clusterin isoforms. Knowledge of wild species reproductive biology is crucial for an understanding of their survival strategies and adaptation in a changing environment.

Establishing the hypoosmotic swelling test for sperm analysis in collared peccaries (Pecari tajacu) / Estabelecimento do teste hiposmótico para a análise de sêmen de catetos (Pecari tajacu)

Soluções hiposmóticas com diferentes concentrações (0, 50, 100, 150, 200mOsm/L) foram testadas para a avaliação funcional da membrana espermática de catetos (n=13). Foi verificado que o número de espermatozoides reagidos diminuía (P<0,05) de acordo com o aumento da osmolaridade do meio. A maior porcentagem (71,8%) de espermatozoides reagidos, bem como a menor variação nas respostas osmóticas, foi detectada com o uso de água destilada (0mOsm/L) (P<0,05), a qual também apresentou a menor variação nos resultados, de acordo com os erros padrão verificados. Em conclusão, a água destilada aparenta ser uma solução adequada para o uso no teste hiposmótico para sêmen de catetos.

Morphology, morphometry and ultrastructure of captive six-banded armadillo (Euphractus sexcinctus) sperm.

We analyzed the sperm characteristics of captive six-banded armadillos (Euphractus sexcinctus), by the assessment of sperm morphology, morphometry, and ultrastructure. In general, armadillo's ejaculates present more than 80% of sperm within the range considered normal for sperm morphology currently accepted for other mammals. Coiled tails (3.9%) and detached heads (2.8%) were the defects most frequently verified. The morphometric analysis revealed that the total length of six-banded armadillo sperm is 77.6±1.2µm, and the length of the tail is 64.7±1.1µm on average. They also present a big head that corresponds to 16.6% of the entire sperm. Through transmission electron microscopy, we identified the presence of electron lucent points into the nucleus and the presence of about 45 mitochondria spirals in the mitochondrial sheath midpiece as a peculiarity of the six-banded armadillo sperm.

Shear viscosity and nonlinear behavior of whole blood under large amplitude oscillatory shear.

We investigated experimentally the rheological behavior of whole human blood subjected to large amplitude oscillatory shear under strain control to assess its nonlinear viscoelastic response. In these rheological tests, the shear stress response presented higher harmonic contributions, revealing the nonlinear behavior of human blood that is associated with changes in its internal microstructure. For the rheological conditions investigated, intra-cycle strain-stiffening and intra-cycle shear-thinning behavior of the human blood samples were observed and quantified based on the Lissajous-Bowditch plots. The results demonstrated that the dissipative nature of whole blood is more intense than its elastic component. We also assessed the effect of adding EDTA anticoagulant on the shear viscosity of whole blood subjected to steady shear flow. We found that the use of anticoagulant in appropriate concentrations did not influence the shear viscosity and that blood samples without anticoagulant preserved their rheological characteristics approximately for up to 8 minutes before coagulation became significant.

Interactions between straw size and thawing rates on the cryopreservation of agouti (Dasyprocta aguti) epididymal sperm.

This study verifies the interactions between straw size and thawing rates and their impact on the epididymal sperm from this species. Caudae epididymidum from 10 agoutis were subjected to retrograde washing using a coconut water extender (ACP-109c(®) ). Epididymal sperm were evaluated and extended in ACP-109c(®) plus egg yolk (20%) and glycerol (6%). The samples were packaged in 0.25- or 0.50-ml straws, frozen in liquid nitrogen and thawed at 37°C/1 min or 70°C/8 s, followed by a re-evaluation. The use of 0.25-ml straws thawed at 37°C/1 min provided a value of 26.6% for sperm motility. No interactions between straw size and thawing rates were verified on agouti sperm (p > 0.05), but when 0.5-ml straws were thawed at 70°C/8 s, sperm vigour decreased significantly (p < 0.05). It is recommended that the agouti epididymal sperm cryopreserved in ACP-109c(®) extender should be packaged in 0.25- or 0.50-ml straws and thawed at 37°C/60 s.

Assessment of sperm survival and functional membrane integrity of the six-banded armadillo (Euphractus sexcinctus).

The objective was to evaluate sperm survival in the six-banded armadillo, using a thermoresistance test, and to compare sugar solutions with varying osmolarities to analyze the integrity of the functional sperm plasma membrane in this species. Twelve ejaculates were obtained from four mature males by electroejaculation and evaluated for sperm motility, vigor, live sperm, and morphology. Sperm survival was evaluated during a thermoresistance test at 34 °C (the body temperature of this species). The functional integrity of the plasma membrane was evaluated by means of the hypo-osmotic swelling test (HOST), using solutions of varying osmolarities (0, 50, 100, and 150 mOsm/L). During the thermoresistance test, at each evaluation, there was a reduction (P < 0.05) in mean values for sperm motility, sperm vigor, and percentage of live sperm (no movement was observed at 360 min). Sperm survival varied among individual armadillos (P < 0.05). In two individuals, sperm vigor was significantly enhanced when semen was diluted in Tris extender. The response of armadillo sperm to the HOST varied among individuals (P < 0.05). On average, maximal values (P < 0.05) of reactive sperm (59%) were detected with 50 mOsm/L solution; furthermore, this concentration had the largest significant positive correlation (r = 0.84) to live sperm percentage. In conclusion, six-banded armadillos had significant individual variation with regard to sperm survival in a thermoresistance test at 34 °C; in some individuals, sperm survived until 360 min. The use of a 50 mOsm/L fructose solution was recommended for conducting a HOST in this species.

Extensional flow of blood analog solutions in microfluidic devices.

In this study, we show the importance of extensional rheology, in addition to the shear rheology, in the choice of blood analog solutions intended to be used in vitro for mimicking the microcirculatory system. For this purpose, we compare the flow of a Newtonian fluid and two well-established viscoelastic blood analog polymer solutions through microfluidic channels containing both hyperbolic and abrupt contractions∕expansions. The hyperbolic shape was selected in order to impose a nearly constant strain rate at the centerline of the microchannels and achieve a quasihomogeneous and strong extensional flow often found in features of the human microcirculatory system such as stenoses. The two blood analog fluids used are aqueous solutions of a polyacrylamide (125 ppm w∕w) and of a xanthan gum (500 ppm w∕w), which were characterized rheologically in steady-shear flow using a rotational rheometer and in extension using a capillary breakup extensional rheometer (CaBER). Both blood analogs exhibit a shear-thinning behavior similar to that of whole human blood, but their relaxation times, obtained from CaBER experiments, are substantially different (by one order of magnitude). Visualizations of the flow patterns using streak photography, measurements of the velocity field using microparticle image velocimetry, and pressure-drop measurements were carried out experimentally for a wide range of flow rates. The experimental results were also compared with the numerical simulations of the flow of a Newtonian fluid and a generalized Newtonian fluid with shear-thinning behavior. Our results show that the flow patterns of the two blood analog solutions are considerably different, despite their similar shear rheology. Furthermore, we demonstrate that the elastic properties of the fluid have a major impact on the flow characteristics, with the polyacrylamide solution exhibiting a much stronger elastic character. As such, these properties must be taken into account in the choice or development of analog fluids that are adequate to replicate blood behavior at the microscale.

Hydrostatic pressure rescues native protein from aggregates.

Misfolding and misassembly of proteins are major problems in the biotechnology industry, in biochemical research, and in human disease. Here we describe a novel approach for reversing aggregation and increasing refolding by application of hydrostatic pressure. Using P22 tailspike protein as a model system, intermediates along the aggregation pathway were identified and quantitated by size-exclusion high-performance liquid chromatography (HPLC). Tailspike aggregates were subjected to hydrostatic pressures of 2.4 kbar (35,000 psi). This treatment dissociated the tailspike aggregates and resulted in increased formation of native trimers once pressure was released. Tailspike trimers refolded at these pressures were fully active for formation of infectious viral particles. This technique can facilitate conversion of aggregates to native proteins without addition of chaotropic agents, changes in buffer, or large-scale dilution of reagents required for traditional refolding methods. Our results also indicate that one or more intermediates at the junction between the folding and aggregation pathways is pressure sensitive. This finding supports the hypothesis that specific determinants of recognition exist for protein aggregation, and that these determinants are similar to those involved in folding to the native state. An increased understanding of this specificity should lead to improved refolding methods.

Cavity defects in the procapsid of bacteriophage P22 and the mechanism of capsid maturation.

Bacteriophage P22 belongs to a family of double-stranded DNA viruses that share common morphogenetic features like DNA packaging into a procapsid precursor and maturation. Maturation involves cooperative expansion of the procapsid shell with concomitant lattice stabilization. The expansion is thought to be mediated by movement of two coat protein domains around a hinge. The metastable conformation of subunit within the procapsid lattice is considered to constitute a late folding intermediate. In order to understand the mechanism of expansion it is necessary to characterize the interactions stabilizing procapsid and mature capsid lattices, respectively. We employ pressure dissociation to compare subunit packing within the procapsid and expanded lattice. Procapsid shells contain larger cavities than the expanded shells, presumably due to polypeptide packing defects. These defects contribute to the metastable nature of the procapsid lattice and are cured during expansion. Improved packing contributes to the increased stability of the expanded shell. Comparison of two temperature-sensitive folding (tsf) mutants of coat protein (T294I and W48Q) with wild-type coat revealed that both mutations markedly destabilized the procapsid shell and yet had little effect on relative stability of the monomeric subunit. Thus, the regions affected by these packing defects constitute subunit interfaces of the procapsid shell. The larger activation volume of pressure dissociation observed for both T294I and W48Q indicates that the decreased stability of these particles is due to increase of cavity defects. These defects in the procapsid lattice are cured upon expansion suggesting that the intersubunit contacts affected by tsf mutations are absent or rearranged in the mature shell. The energetics of the in vitro expansion reaction also suggests that entropic stabilization contributes to the large free energy barrier for expansion.

Morphological and/or functional imagiology diagnosis of epiphora.

Several tests and examinations are necessary for an accurate diagnosis of disorders of the lacrimal drainage system. The AA studied 100 patients with epiphora, divided in two groups. Forty patients, first group (I), aged between 4 and 78 years old (mean age 47.8 +/- 9.6 years), were examined using the classical tests for the study of epiphora, sequential dacryoscintigraphy (SD) and conventional subtraction macrodacryocystrography (CSMD). In the second group (II), 60 patients (aged 45.5 +/- 8.7 years) were studied using the classical tests and by digital subtraction macrodacryocystography (DSMD). The results showed that when functional epiphora is present, there is no difference between a simple clinical approach and sequential dacryoscintigraphy. However, when information is needed regarding choice of surgical approach, DSMD appears to give the best results.

Digital subtraction macrodacryocystography by videotechnique.

Digital subtraction macrodacryocystography (DSMD) has proved to be the best imaging method for diagnosing situations of stenosis of the lacrimal system. The examination is performed with a computer-controlled X-ray unit with a C-arc coupled to an image intensifier TV system with a fluoroscopic control. All the findings were recorded on videotape thus allowing good dynamic flow documentation and contributing to improved scientific analysis.