Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.445
Filtrar
1.
Am J Vet Res ; 80(7): 657-662, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31246125

RESUMO

OBJECTIVE: To use duplex Doppler ultrasonography to compare gastrointestinal activity in healthy sedated versus nonsedated rabbits and to evaluate agreement between B-mode and pulsed-wave Doppler (PWD) ultrasonographic measurements. ANIMALS: 10 healthy client-owned rabbits brought for routine physical examination and 11 brought for routine ovariohysterectomy or castration. PROCEDURES: Duplex Doppler ultrasonography of the gastrointestinal tract was performed once for the 10 rabbits that underwent physical examination and twice (before and after presurgical sedation) for the 11 rabbits that underwent routine ovariohysterectomy or castration. Mean number of peristaltic contractions during a 30-second period was determined for the stomach, duodenum, jejunum, cecum, and colon from B-mode and PWD ultrasonographic images that had been video recorded. Findings for the duodenum and jejunum were compared between B-mode and PWD ultrasonography and between sedated and nonsedated rabbits. RESULTS: Duodenal and jejunal segments had measurable peristaltic waves; however, the stomach, cecum, and colon had no consistent measurable activity. B-mode and PWD ultrasonographic measurements for the duodenum and jejunum had high agreement. No significant difference was identified between nonsedated and sedated rabbits in mean number of peristaltic contractions of the duodenum or jejunum. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that both B-mode and PWD ultrasonography of the duodenum and jejunum may be suitable for noninvasive evaluation of small intestinal motility in rabbits and that the sedation protocol used in this study had no impact on measured peristaltic values.


Assuntos
Trato Gastrointestinal/fisiologia , Peristaltismo , Coelhos/fisiologia , Ultrassonografia Doppler Dupla/veterinária , Ultrassonografia Doppler de Pulso/veterinária , Animais , Sedação Consciente/veterinária , Sedação Profunda/veterinária , Feminino , Masculino
4.
Clin Exp Nephrol ; 23(5): 621-628, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30729347

RESUMO

BACKGROUND: Acute exercise reduces renal blood flow (RBF). However, the effect of exercise intensity on RBF in patients with chronic kidney disease (CKD) stage 2 is not known. We investigated the association between RBF and exercise intensity in patients with CKD stage 2 using pulsed Doppler ultrasonography. METHODS: Eight men with CKD stage 2 (cystatin C-based estimate of glomerular filtration rate: 60-89 ml/min/1.73 m2) participated in this study. Using a bicycle ergometer, participants undertook a maximal graded exercise test (MGET) (experiment 1) and a multi-stage exercise test (experiment 2) to determine their lactate threshold (LT). Participants undertook a multi-stage exercise test for 4-min each. Workloads of 60%, 80%, 100%, 120%, and 140% of LT were used in experiment 3. RBF was measured by pulsed Doppler ultrasonography at rest, immediately after exercise, and 1 h after exercise in experiment 1, and at rest and immediately after each exercise bout in experiment 3. RESULTS: Renal blood flow after the MGET was 52% lower than at rest, and did not recover as well as after the exercise test. Cross-sectional area (CSA) was significantly lower after graded exercise. RBF tended to be lower at 100% of LT and was significantly lower at 120% of LT. CSA was significantly lower at 100% of LT. CONCLUSIONS: Renal blood flow does not change during exercise until the LT is reached. These findings may assist in making appropriate exercise recommendations to patients with CKD stage 2.


Assuntos
Exercício/fisiologia , Circulação Renal , Insuficiência Renal Crônica/fisiopatologia , Idoso , Humanos , Masculino , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/diagnóstico por imagem , Ultrassonografia Doppler de Pulso
6.
Pediatr Allergy Immunol ; 30(4): 443-450, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30801809

RESUMO

BACKGROUND: Fetal growth restriction is associated with higher risks of childhood respiratory morbidity. Fetal blood flow adaptations might contribute to these associations. We examined the associations of fetal umbilical, cerebral, and pulmonary blood flow with wheezing patterns, lung function, and asthma in childhood. METHODS: In a population-based prospective cohort study among 903 children, we measured fetal umbilical, cerebral, and pulmonary blood flow by pulsed-wave Doppler at a median gestational age of 30.3 (95% range 28.8-32.3) weeks. We obtained information about wheezing patterns until the age of 6 years by questionnaires. Lung function was measured by spirometry and information about current asthma was obtained by questionnaire at the age of 10 years. RESULTS: Results showed a non-significant relationship between a higher umbilical artery pulsatility index (PI) and umbilical artery PI/cerebral artery PI ratio, indicating fetal blood flow redistribution at the expense of the trunk, with higher risks of early wheezing (OR [95% CI]: 2.07 (0.70-6.10) and 2.74 (0.60, 12.62) per unit increase, respectively). A higher pulmonary artery time velocity integral, indicating higher pulmonary vascular resistance, was associated with a higher risk of late/persistent wheezing (Z-score 1.14 [1.01-1.29]). A higher middle cerebral artery PI was associated with a higher FEV1 /FVC (Z-score [95% CI]: 0.21 [0.01-0.42]). Results did not materially change after additional adjustment for birth and growth characteristics. CONCLUSION: Third-trimester fetal blood flow patterns might be related to childhood respiratory health. These findings should be considered as hypothesis generating and need further replication.


Assuntos
Asma/epidemiologia , Encéfalo/irrigação sanguínea , Pulmão/irrigação sanguínea , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Cordão Umbilical/irrigação sanguínea , Criança , Estudos de Coortes , Feminino , Sangue Fetal , Feto , Humanos , Pulmão/metabolismo , Grupos Populacionais , Gravidez , Estudos Prospectivos , Fluxo Sanguíneo Regional , Testes de Função Respiratória , Sons Respiratórios , Ultrassonografia Doppler de Pulso
7.
Ultrasound Obstet Gynecol ; 53(2): 251-255, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29808615

RESUMO

OBJECTIVES: To develop an objective image-scoring system for pulsed-wave Doppler measurement of maternal uterine and fetal umbilical arteries, and evaluate how this compares with subjective assessment. METHODS: As an extension to the INTERGROWTH-21st Project, we developed a scoring system based on six predefined criteria for uterine and umbilical artery pulsed-wave Doppler measurements. Objective evaluation using the scoring system was compared with subjective assessment which consisted of classifying an image as simply acceptable or unacceptable. Based on sample size estimation, a total of 120 umbilical and uterine artery Doppler images were selected randomly from the INTERGROWTH-21st image database. Two independent reviewers evaluated all images in a blinded fashion, both subjectively and using the six-point scoring system. Percentage agreement and kappa statistic were compared between the two methods. RESULTS: The overall agreement between reviewers was higher for objective assessment using the scoring system (agreement, 85%; adjusted kappa, 0.70) than for subjective assessment (agreement, 70%; adjusted kappa, 0.47). For the six components of the scoring system, the level of agreement (adjusted kappa) was 0.97 for anatomical site, 0.88 for sweep speed, 0.77 for magnification, 0.68 for velocity scale, 0.68 for image clarity and 0.65 for angle of insonation. CONCLUSION: In quality assessment of umbilical and uterine artery pulsed-wave Doppler measurements, our proposed objective six-point image-scoring system is associated with greater reproducibility than is subjective assessment. We recommend this as the preferred method for quality control, auditing and teaching. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Ultrassonografia Doppler de Pulso/normas , Ultrassonografia Pré-Natal/normas , Feminino , Humanos , Gravidez , Estudos Prospectivos , Controle de Qualidade , Reprodutibilidade dos Testes , Artérias Umbilicais/irrigação sanguínea , Artérias Umbilicais/diagnóstico por imagem , Artéria Uterina/diagnóstico por imagem
8.
J Obstet Gynaecol Res ; 45(1): 104-112, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30230132

RESUMO

AIM: To develop a combined predictive model for preterm and term pre-eclampsia (PE) during the first trimester of pregnancy. METHODS: This investigation was a nested case-control study in singleton pregnancies at the Maternal-Fetal Medicine Unit, University of Chile Hospital. A priori risks for preterm and term PE were calculated by multivariate logistic regression analyses. Biophysical markers were log10 -transformed and expressed as multiples of the median. A multivariate logistic regression analysis was used to estimate a combined predictive model of preterm and term PE. Detection rates at different cut-off points were determined by a receiver operator curve analysis of a posteriori risks. RESULTS: First trimester mean arterial pressure and uterine artery Doppler pulsatility index were significantly higher in women who develop PE than in the unaffected group. The detection rate of preterm PE based on maternal characteristics and biophysical markers was 72% at a 10% false-positive rate, corresponding to a cut-off risk of 1 in 50. The detection rate for term PE was 30% at a 10% false-positive rate. CONCLUSION: Preterm PE can be predicted by a combination of maternal characteristics and biophysical markers. However, first trimester screening is less valuable for term PE.


Assuntos
Pressão Arterial/fisiologia , Pré-Eclâmpsia/diagnóstico , Artéria Uterina/diagnóstico por imagem , Adulto , Biomarcadores , Estudos de Casos e Controles , Feminino , Humanos , Pré-Eclâmpsia/diagnóstico por imagem , Pré-Eclâmpsia/fisiopatologia , Gravidez , Primeiro Trimestre da Gravidez , Prognóstico , Ultrassonografia Doppler em Cores , Ultrassonografia Doppler de Pulso
9.
Taiwan J Obstet Gynecol ; 57(5): 683-687, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30342651

RESUMO

OBJECTIVE: To determine the normal values of flow mediated dilatation (FMD) in Taiwanese women with normal singleton pregnancies for the early detection of preeclampsia. MATERIALS AND METHODS: Data of women with normal singleton pregnancies seen at the Tri-Service General Hospital and Taiji Clinic between January 2014 and December 2015 were collected and analyzed. FMD was measured using high-resolution ultrasonography of the brachial artery for the assessment of endothelial function at the first and second trimester. The relationship between the FMD values and maternal gestational age was analyzed. RESULTS: A total of 122 pregnant women were included in the study. Systole FMD values first and second trimester were 9.05 ± 3.72 and 10.93 ± 3.74, respectively; and the diastole were 9.24 ± 3.64 and 11.18 ± 3.93, respectively. FMD and gestational age were positively correlated (systole, p = 0.0175; diastole, p = 0.0149). CONCLUSION: The normal values of FMD in Taiwanese women with normal singleton pregnancies were established, and data suggests that both systolic and diastolic FMD increase with gestational age. Because of the high failure rate, measurement of FMD may not be suitable as a routine clinical examination.


Assuntos
Artéria Braquial , Pré-Eclâmpsia/diagnóstico , Vasodilatação/fisiologia , Adulto , Diagnóstico Precoce , Feminino , Idade Gestacional , Humanos , Pré-Eclâmpsia/fisiopatologia , Gravidez , Taiwan , Ultrassonografia Doppler de Pulso
10.
J Vasc Surg Venous Lymphat Disord ; 6(6): 748-757, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30336903

RESUMO

Venous duplex ultrasound imaging of the retroperitoneal iliac veins and vena cava has been slow to be adopted into everyday use; however, current ultrasound technology allows more depth of penetration with improved image resolution. Gray-scale, color flow, and pulsed wave Doppler modalities are ideal for evaluation of the femoral-iliocaval outflow tract. Additional tools, such as chroma tint, power Doppler, and penetration harmonics, are useful for image optimization. Duplex ultrasound using the techniques described here needs to be compared and correlated with intravascular ultrasound imaging in a formal study that also looks at clinical outcomes and quality of life measures.


Assuntos
Veia Ilíaca/diagnóstico por imagem , Ultrassonografia Doppler Dupla/métodos , Doenças Vasculares/diagnóstico por imagem , Veia Cava Inferior/diagnóstico por imagem , Velocidade do Fluxo Sanguíneo , Hemodinâmica , Humanos , Veia Ilíaca/fisiopatologia , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Ultrassonografia Doppler em Cores , Ultrassonografia Doppler de Pulso , Doenças Vasculares/fisiopatologia , Veia Cava Inferior/fisiopatologia
11.
Cardiovasc Ultrasound ; 16(1): 22, 2018 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-30285774

RESUMO

BACKGROUND: The detection of regional wall motion abnormalities is the cornerstone of stress echocardiography. Today, stress echo shows increasing trends of utilization due to growing concerns for radiation risk, higher cost and stronger environmental impact of competing techniques. However, it has also limitations: underused ability to identify factors of clinical vulnerability outside coronary artery stenosis; operator-dependence; low positivity rate in contemporary populations; intermediate risk associated with a negative test; limited value of wall motion beyond coronary artery disease. Nevertheless, stress echo has potential to adapt to a changing environment and overcome its current limitations. INTEGRATED-QUADRUPLE STRESS-ECHO: Four parameters now converge conceptually, logistically, and methodologically in the Integrated Quadruple (IQ)-stress echo. They are: 1- regional wall motion abnormalities; 2-B-lines measured by lung ultrasound; 3-left ventricular contractile reserve assessed as the stress/rest ratio of force (systolic arterial pressure by cuff sphygmomanometer/end-systolic volume from 2D); 4- coronary flow velocity reserve on left anterior descending coronary artery (with color-Doppler guided pulsed wave Doppler). IQ-Stress echo allows a synoptic functional assessment of epicardial coronary artery stenosis (wall motion), lung water (B-lines), myocardial function (left ventricular contractile reserve) and coronary small vessels (coronary flow velocity reserve in mid or distal left anterior descending artery). In "ABCD" protocol, A stands for Asynergy (ischemic vs non-ischemic heart); B for B-lines (wet vs dry lung); C for Contractile reserve (weak vs strong heart); D for Doppler flowmetry (warm vs cold heart, since the hyperemic blood flow increases the local temperature of the myocardium). From the technical (acquisition/analysis) viewpoint and required training, B-lines are the kindergarten, left ventricular contractile reserve the primary (for acquisition) and secondary (for analysis) school, wall motion the university, and coronary flow velocity reserve the PhD program of stress echo. CONCLUSION: Stress echo is changing. As an old landline telephone with only one function, yesterday stress echo used one sign (regional wall motion abnormalities) for one patient with coronary artery disease. As a versatile smart-phone with multiple applications, stress echo today uses many signs for different pathophysiological and clinical targets. Large scale effectiveness studies are now in progress in the Stress Echo2020 project with the omnivorous "ABCD" protocol.


Assuntos
Estenose Coronária/diagnóstico por imagem , Estenose Coronária/fisiopatologia , Ecocardiografia sob Estresse/métodos , Insuficiência Cardíaca/diagnóstico por imagem , Ultrassonografia Doppler de Pulso/métodos , Idoso , Circulação Coronária/fisiologia , Ecocardiografia sob Estresse/normas , Feminino , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Imagem Multimodal/métodos , Contração Miocárdica/fisiologia , Guias de Prática Clínica como Assunto , Sensibilidade e Especificidade , Volume Sistólico/fisiologia
13.
J Vasc Access ; 19(5): 446-454, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30192183

RESUMO

PURPOSE: Perturbed vascular access hemodynamics is considered a potential driver of intimal hyperplasia, the leading cause of vascular access failure. To improve vascular access patency, a modular anastomotic valve device has been designed to normalize venous flow between hemodialysis periods while providing normal vascular access during hemodialysis. The objective of this study was to quantify the effects of arteriovenous graft flow rate on modular anastomotic valve device vascular access hemodynamics under realistic hemodialysis conditions. METHODS: Modular anastomotic valve device inlet and outlet flow conditions and velocity profiles were measured by ultrasound Doppler in a vascular access flow loop replicating arteriovenous graft flow rates of 800, 1000, and 1500 mL/min. Fluid-structure interaction simulations were performed to identify low wall shear stress regions on the vein wall and to characterize them in terms of temporal shear magnitude, oscillatory shear index, and relative residence time. The model was validated with respect to the Doppler measurements. RESULTS: The low wall shear stress region generated downstream of the anastomosis under low and moderate arteriovenous graft flow rates was eliminated under the highest arteriovenous graft flow rate. Increase in arteriovenous graft flow rate from 800 to 1500 mL/min resulted in a substantial increase in wall shear stress magnitude (27-fold increase in temporal shear magnitude), the elimination of wall shear stress bidirectionality (0.20-point reduction in oscillatory shear index), and a reduction in flow stagnation (98% decrease in relative residence time). While the results suggest the ability of high arteriovenous graft flow rates to protect the venous wall from intimal hyperplasia-prone hemodynamics, they indicate their adverse impact on the degree of venous hemodynamic abnormality.


Assuntos
Derivação Arteriovenosa Cirúrgica/instrumentação , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Hemodinâmica , Diálise Renal , Derivação Arteriovenosa Cirúrgica/efeitos adversos , Velocidade do Fluxo Sanguíneo , Implante de Prótese Vascular/efeitos adversos , Simulação por Computador , Oclusão de Enxerto Vascular/etiologia , Oclusão de Enxerto Vascular/patologia , Oclusão de Enxerto Vascular/fisiopatologia , Humanos , Hiperplasia , Modelos Anatômicos , Modelos Cardiovasculares , Neointima , Desenho de Prótese , Estresse Mecânico , Ultrassonografia Doppler de Pulso , Grau de Desobstrução Vascular
14.
J Med Vasc ; 43(4): 255-261, 2018 Jul.
Artigo em Francês | MEDLINE | ID: mdl-29981734

RESUMO

Lower extremity peripheral artery disease is a frequent disease. Arterial Doppler waveforms analysis is a key element in vascular medicine, especially to diagnose lower peripheral artery disease. Although Doppler waveforms are often used, descriptions are highly heterogeneous. This review presents the simplified Saint-Bonnet classification that is tought to vascular medicine residents in order to homogenize arterial flow description.


Assuntos
Perna (Membro)/irrigação sanguínea , Doença Arterial Periférica/fisiopatologia , Ultrassonografia Doppler de Pulso , Falso Aneurisma/fisiopatologia , Fístula Arteriovenosa/fisiopatologia , Classificação , Efeito Doppler , Humanos , Placa Aterosclerótica/fisiopatologia , Fluxo Pulsátil
15.
J Stroke Cerebrovasc Dis ; 27(10): 2691-2695, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30033099

RESUMO

BACKGROUND AND PURPOSE: Spontaneous intracranial arterial dissections are characterized by the sudden disruption of the internal elastic lamina in the intracranial arteries. The purpose of our retrospective study was to investigate whether patients with nontraumatic intracranial arterial dissections had normal endothelial function. METHODS: The study included symptomatic patients with nontraumatic intracranial arterial dissections who underwent an endothelial function test. Controls were selected from headache patients matched for sex and age. Endothelial function was assessed using flow-mediated dilatation. We investigated patients' ankle brachial index and pulse wave velocity to determine the degree of atherosclerosis. Patient characteristics, brachial flow-mediated dilatation, ankle brachial index, and pulse wave velocity were compared between the 2 groups. RESULTS: During the study period, there were 22 patients with nontraumatic intracranial arterial dissections matched with 22 controls. Clinical characteristics were compared between the groups. Although there were no significant differences in ankle brachial index or pulse wave velocity between the 2 groups, patients with intracranial arterial dissections had lower flow-mediated dilatation values than controls (median flow-mediated dilatation, 3.95% in dissection patients versus 7.3% in controls, P = .0035). Brachial flow-mediated dilatation was impaired in symptomatic patients with nontraumatic intracranial arterial dissections despite the normal ankle brachial index and pulse wave velocity. CONCLUSIONS: Impaired brachial flow-mediated dilatation is a probable predictor of intracranial arterial dissections.


Assuntos
Aneurisma Dissecante/fisiopatologia , Artéria Braquial/fisiopatologia , Aneurisma Intracraniano/fisiopatologia , Vasodilatação , Adulto , Aneurisma Dissecante/complicações , Aneurisma Dissecante/diagnóstico , Índice Tornozelo-Braço , Artéria Braquial/diagnóstico por imagem , Angiografia Cerebral , Feminino , Humanos , Aneurisma Intracraniano/complicações , Aneurisma Intracraniano/diagnóstico , Masculino , Pessoa de Meia-Idade , Prognóstico , Análise de Onda de Pulso , Fluxo Sanguíneo Regional , Estudos Retrospectivos , Fatores de Risco , Ultrassonografia Doppler de Pulso
16.
Am J Physiol Regul Integr Comp Physiol ; 315(4): R759-R767, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29995458

RESUMO

We examined if the diving-induced vascular changes in the peripheral and cerebral circulation could be prevented by oral antioxidant supplementation. Fourteen divers performed a single scuba dive to eighteen meter sea water for 47 min. Twelve of the divers participated in a follow-up study involving breathing 60% of oxygen at ambient pressure for 47 min. Before both studies, participants ingested vitamin C (2 g/day) or a placebo capsule for 6 days. After a 2-wk washout, the study was repeated with the different condition. Endothelium-dependent vasodilator function of the brachial artery was assessed pre- and postintervention using the flow-mediated dilation (FMD) technique. Transcranial Doppler ultrasound was used to measure intracranial blood velocities pre- and 90 min postintervention. FMD was reduced by ∼32.8% and ∼21.2% postdive in the placebo and vitamin C trial and posthyperoxic condition in the placebo trial by ∼28.2% ( P < 0.05). This reduction in FMD was attenuated by ∼10% following vitamin C supplementation in the hyperoxic study ( P > 0.05). Elevations in intracranial blood velocities 30 min after surfacing from diving were reduced in the vitamin C study compared with the placebo trial ( P < 0.05). O2 breathing had no postintervention effects on intracranial velocities ( P > 0.05). Prophylactic ingestion of vitamin C effectively abrogated peripheral vascular dysfunction following exposure to 60% O2 but did not abolish the postdive decrease in FMD. Transient elevations of intracranial velocities postdive were reduced by vitamin C. These findings highlight the differential influence of vitamin C on peripheral and cerebral circulations following scuba diving, which are only partly mediated via hyperoxia.


Assuntos
Antioxidantes/administração & dosagem , Ácido Ascórbico/administração & dosagem , Artéria Braquial/efeitos dos fármacos , Circulação Cerebrovascular/efeitos dos fármacos , Mergulho , Hiperóxia/fisiopatologia , Vasodilatação/efeitos dos fármacos , Administração Oral , Adulto , Velocidade do Fluxo Sanguíneo , Artéria Braquial/diagnóstico por imagem , Artéria Braquial/fisiopatologia , Croácia , Método Duplo-Cego , Ecocardiografia , Humanos , Hiperóxia/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Ultrassonografia Doppler de Pulso , Ultrassonografia Doppler Transcraniana/métodos
17.
J Stroke Cerebrovasc Dis ; 27(10): 2703-2706, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30049518

RESUMO

BACKGROUND: Impairment of vasodilatory capacity reflecting reduced cerebrovascular reserve was previously shown in adults with sickle cell disease (SCD) and might play a role in the pathophysiology of stroke in such patients. We examined the hypothesis that children with SCD would also have a higher frequency of impaired cerebral vasoreactivity when compared with healthy age- and gender-matched controls. METHODS: Patients were recruited from our hematology outpatient clinic. All SCD patients aged 10-18 years without a history of symptomatic stroke as well as age- and gender-matched healthy children were evaluated with transcranial Doppler (TCD) ultrasonography, with breath-holding maneuver. Breath-holding index (BHI) was calculated by dividing the percentage increase in mean flow velocity occurring during breath holding by the length of time subjects hold their breath after a normal inspiration. BHI was considered abnormal if less than .69. RESULTS: TCD was performed in 42 patients (mean age 12.7 ± 2.2 years) and 20 controls (mean age 13.90 ± 3.04 years). Blood flow velocities were higher in patients with SCD than in controls in all arteries evaluated (P < .001). BHI values in patients with SCD were significantly lower than in control subjects (1.27 ± .65 versus 1.74 ± .15, P = .013 on the left and 1.16 ± .45 versus 1.61 ± .11, P = .002 on the right). BHI was abnormal in 19% of the patients and in none of the controls, P = .036. CONCLUSIONS: Children with SCD may have impaired cerebral vasoreactivity, with low BHI values suggesting a reduced autoregulation capacity.


Assuntos
Anemia Falciforme/diagnóstico por imagem , Artérias Cerebrais/diagnóstico por imagem , Circulação Cerebrovascular , Ultrassonografia Doppler de Pulso , Ultrassonografia Doppler Transcraniana/métodos , Vasodilatação , Adolescente , Fatores Etários , Anemia Falciforme/fisiopatologia , Velocidade do Fluxo Sanguíneo , Suspensão da Respiração , Estudos de Casos e Controles , Artérias Cerebrais/fisiopatologia , Criança , Feminino , Homeostase , Humanos , Masculino , Valor Preditivo dos Testes
18.
J Diabetes Res ; 2018: 4561309, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29707583

RESUMO

The availability of an animal model able to reliably mirror organ damage occurring in metabolic diseases is an urgent need. These models, mostly rodents, have not been fully characterized in terms of cardiovascular, renal, and hepatic ultrasound parameters, and only sparse values can be found in literature. Aim of this paper is to provide a detailed, noninvasive description of the heart, vessels, liver, and kidneys of the db/db mouse by ultrasound imaging. Sixteen wild type and thirty-four db/db male mice (11-week-old) were studied. State-of-the-art ultrasound technology was used to acquire images of cardiovascular, renal, and hepatic districts. A set of parameters describing function of the selected organs was evaluated. db/db mice are characterized by systolic and diastolic dysfunction, confirmed by strain analysis. Abdominal aortic and carotid stiffness do not seem to be increased in diabetic rodents; furthermore, they are characterized by a smaller mean diameter for both vessels. Renal microcirculation is significantly compromised, while liver steatosis is only slightly higher in db/db mice than in controls. We offer here for the first time an in vivo detailed ultrasonographic characterization of the db/db mouse, providing a useful tool for a thoughtful choice of the right rodent model for any experimental design.


Assuntos
Aorta Abdominal/diagnóstico por imagem , Artéria Carótida Primitiva/diagnóstico por imagem , Diabetes Mellitus/diagnóstico por imagem , Coração/diagnóstico por imagem , Fígado/diagnóstico por imagem , Imagem de Perfusão/métodos , Artéria Renal/diagnóstico por imagem , Ultrassonografia Doppler de Pulso , Animais , Aorta Abdominal/fisiopatologia , Glicemia/metabolismo , Artéria Carótida Primitiva/fisiopatologia , Diabetes Mellitus/sangue , Diabetes Mellitus/genética , Diabetes Mellitus/fisiopatologia , Modelos Animais de Doenças , Ecocardiografia Doppler de Pulso , Predisposição Genética para Doença , Coração/fisiopatologia , Lipídeos/sangue , Fígado/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Microcirculação , Fenótipo , Valor Preditivo dos Testes , Artéria Renal/fisiopatologia , Circulação Renal , Rigidez Vascular , Função Ventricular Esquerda
19.
Vet Comp Oncol ; 16(4): 467-477, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29797763

RESUMO

Combretastatin A4-phosphate (CA4P) is an anti-tumour vascular targeting agent which selectively blocks tumour blood flow. Research on CA4P in rodent tumour models is extensive; however, knowledge of its effect on spontaneous cancer is scarce. This study was conducted in canine patients with spontaneous solid tumours. The goal was to assess the toxicity and efficacy of CA4P in various spontaneous tumour types. Eight dogs with spontaneous tumours were enrolled and treated with a single dose of 75 mg m-2 intravenous CA4P. The dogs were screened and monitored before and after injection. Pre- and post-treatment tumour blood flow was analysed in vivo by power Doppler ultrasound (PDUS) and contrast-enhanced ultrasound (CEUS). Vessel destruction and tumour necrosis were evaluated by histopathology. Clinically relevant toxicity was limited to one case of temporary tetraparesis; other adverse events were mild. Significant cardiovascular changes were mostly confined to changes in heart rate and cTnI levels. Macroscopic tumour size reduction was evident in 2 dogs. Based on PDUS and CEUS, CA4P induced a significant decrease in vascular index and tumour blood flow. Post-treatment, histopathology revealed a significant increase of necrotic tumoural tissue and a significant reduction in microvessel density in tumoural tissue. Anti-vascular and necrotizing effects of CA4P were documented in a variety of canine spontaneous cancers with only minimal side effects. This is the first study reporting the administration of CA4P to canine cancer patients with in vivo and ex vivo assessment, and a first step toward implementing CA4P in combination therapies in veterinary oncology patients. The use of CA4P in canine patients was approved and registered by the Belgian Federal Agency for Medicines and Health Products (FAMHP) (approval number 0002588, registration number 6518 ID 2F12).


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Doenças do Cão/tratamento farmacológico , Neoplasias/veterinária , Neovascularização Patológica/veterinária , Estilbenos/uso terapêutico , Animais , Antineoplásicos Fitogênicos/administração & dosagem , Contagem de Células Sanguíneas/veterinária , Doenças do Cão/diagnóstico por imagem , Cães , Feminino , Injeções Intravenosas/veterinária , Masculino , Neoplasias/irrigação sanguínea , Neoplasias/tratamento farmacológico , Neovascularização Patológica/diagnóstico por imagem , Neovascularização Patológica/tratamento farmacológico , Estilbenos/administração & dosagem , Estilbenos/efeitos adversos , Ultrassonografia Doppler de Pulso/veterinária
20.
Biol Sex Differ ; 9(1): 16, 2018 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-29669590

RESUMO

BACKGROUND: Sexual dimorphism in placental size and function has been described. Whether this influences the clinically important umbilical artery (UA) waveform remains controversial, although a few cross-sectional studies have shown sex differences in UA pulsatility index (PI). Therefore, we tested whether fetal sex influences the UA Doppler indices during the entire second half of pregnancy and aimed to establish sex-specific reference ranges for UA Doppler indices if needed. METHODS: Our main objective was to investigate gestational age-associated changes in UA Doppler indices during the second half of pregnancy and compare the values between male and female fetuses. This was a prospective longitudinal study in women with singleton low-risk pregnancies during 19-40 weeks of gestation. UA Doppler indices were serially obtained at a 4-weekly interval from a free loop of the umbilical cord using color-directed pulsed-wave Doppler ultrasonography. Sex-specific reference intervals were calculated for the fetal heart rate (HR), UA PI, resistance index (RI), and systolic/diastolic ratio (S/D) using multilevel modeling. RESULTS: Complete data from 294 pregnancies (a total of 1261 observations from 152 male and 142 female fetuses) were available for statistical analysis, and sex-specific reference ranges for the UA Doppler indices and fetal HR were established for the last half of pregnancy. UA Doppler indices were significantly associated with gestational age (P < 0.0001) and fetal HR (P < 0.0001). Female fetuses had 2-8% higher values for UA Doppler indices than male fetuses during gestational weeks 20+0-36+6 (P < 0.05), but not later. Female fetuses had higher HR from gestational week 26+0 until term (P < 0.05). CONCLUSIONS: We have determined gestational age-dependent sex differences in UA Doppler indices and fetal HR during the second half of pregnancy, and correspondingly established new sex-specific reference ranges intended for refining diagnostics and monitoring individual pregnancies.


Assuntos
Feto/diagnóstico por imagem , Caracteres Sexuais , Ultrassonografia Doppler de Pulso , Artérias Umbilicais/diagnóstico por imagem , Adolescente , Adulto , Feminino , Idade Gestacional , Humanos , Estudos Longitudinais , Masculino , Gravidez , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA