RESUMEN

This study compared strategies to equalize the volume of aerobic exercise performed with different intensities by Wistar rats, based on the distance covered during exercise bouts and energy expenditure (EE, isocaloric sessions) obtained from oxygen uptake (V̇O2) or respiratory exchange ratio (RER). Thirty-three male rats (270.5±12.8 g) underwent maximal exercise tests to determine V̇O2 reserve (V̇O2R), being randomly assigned to three groups: moderate-intensity continuous exercise at speed corresponding to 50% V̇O2R (MIC; n=11); high-intensity continuous exercise at 80% V̇O2R (HIC; n=11); and high-intensity intermittent exercise (HII; n=11) at 60% V̇O2R (3 min) and 80% V̇O2R (4 min). Exercise duration was calculated individually to elicit EE of 5 kcal in each session. No difference between groups was found for total running distance (MIC: 801±46, HIC: 734±42, HII: 885±64 m; P=0.13). Total EE measured by RER was systematically underestimated compared to values obtained from V̇O2 (HII: 4.5% and MIC: 6.2%, P<0.05). Total EE (calculated from V̇O2), and duration of HIC bouts (2.8 kcal and 30.8±2.2 min) were lower (P<0.0001) than in MIC (4.9 kcal and 64.7±1.8 min) and HII (4.7 kcal and 46.9±2.2 min). Predicted and actual values of total V̇O2, total EE, and duration of isocaloric sessions were similar in MIC and HII (P>0.05), which were both higher than in HIC (P<0.0001). In conclusion, the time to achieve a given EE in exercise bouts with different intensities did not correspond to the total distance. Therefore, the volume of aerobic exercise in protocols involving Wistar rats should be equalized using EE rather than total covered distance.

Asunto(s)

Metabolismo Energético/fisiología , Prueba de Esfuerzo , Consumo de Oxígeno/fisiología , Condicionamiento Físico Animal/fisiología , Animales , Prueba de Esfuerzo/normas , Masculino , Modelos Animales , Condicionamiento Físico Animal/métodos , Distribución Aleatoria , Ratas Wistar , Carrera/fisiología

RESUMEN

This study compared strategies to equalize the volume of aerobic exercise performed with different intensities by Wistar rats, based on the distance covered during exercise bouts and energy expenditure (EE, isocaloric sessions) obtained from oxygen uptake (V̇O2) or respiratory exchange ratio (RER). Thirty-three male rats (270.5±12.8 g) underwent maximal exercise tests to determine V̇O2 reserve (V̇O2R), being randomly assigned to three groups: moderate-intensity continuous exercise at speed corresponding to 50% V̇O2R (MIC; n=11); high-intensity continuous exercise at 80% V̇O2R (HIC; n=11); and high-intensity intermittent exercise (HII; n=11) at 60% V̇O2R (3 min) and 80% V̇O2R (4 min). Exercise duration was calculated individually to elicit EE of 5 kcal in each session. No difference between groups was found for total running distance (MIC: 801±46, HIC: 734±42, HII: 885±64 m; P=0.13). Total EE measured by RER was systematically underestimated compared to values obtained from V̇O2 (HII: 4.5% and MIC: 6.2%, P<0.05). Total EE (calculated from V̇O2), and duration of HIC bouts (2.8 kcal and 30.8±2.2 min) were lower (P<0.0001) than in MIC (4.9 kcal and 64.7±1.8 min) and HII (4.7 kcal and 46.9±2.2 min). Predicted and actual values of total V̇O2, total EE, and duration of isocaloric sessions were similar in MIC and HII (P>0.05), which were both higher than in HIC (P<0.0001). In conclusion, the time to achieve a given EE in exercise bouts with different intensities did not correspond to the total distance. Therefore, the volume of aerobic exercise in protocols involving Wistar rats should be equalized using EE rather than total covered distance.

Asunto(s)

Animales , Masculino , Metabolismo Energético/fisiología , Prueba de Esfuerzo , Consumo de Oxígeno/fisiología , Condicionamiento Físico Animal/fisiología , Prueba de Esfuerzo/normas , Modelos Animales , Condicionamiento Físico Animal/métodos , Distribución Aleatoria , Ratas Wistar , Carrera/fisiología

RESUMEN

How cholesterol influences the microcirculation on aging subjects is not well known. This study evaluated moderate hypercholesterolemia effects in, treated or not, lean elderly women on brachial artery reactivity and microcirculatory function using venous occlusion plethysmography (VOP) and nailfold videocapillaroscopy (NVC). Patients (mean age 73 years) were divided into healthy elderly (HE, n=15), treated dyslipidemia with statins during at least 6 months (TDL, n=9) and dyslipidemia (DL, n=9, cholesterol, 257±11 and LDL-cholesterol, 157±24 mg/dl). Young, mean age 23 years, women (YC, n=24), served as controls. Laboratory and anthropometrical analysis, VOP peak forearm blood flow (FBF) during the reactive hyperemia response/baseline FBF (%HYPER) and peak FBF after 0.4 mg sublingual nitroglycerin/baseline FBF (%NITRO) were assessed. NVC capillary density and diameters, maximum red blood cell velocity (RBCV(max)) during reactive hyperemia/baseline RBCV and time to reach RBCV(max) were evaluated. Correlations between %HYPER, %NITRO and plasma cholesterol fractions were performed. Total and LDL-cholesterol were increased only in DL group. Capillary diameters were larger in elderly groups than YC. RBCV(max)/baseline RBCV was reduced in the DL group compared to HE, TDL and YC. %HYPER was lower in DL and normalized in TDL group. YC %HYPER was double of HE. %NITRO decreased from (HE=YC) to TDL and DL groups. There was a significant inverse correlation between LDL-cholesterol, non-HDL-cholesterol and %HYPER/% Nitro. In conclusion, moderate hypercholesterolemia reversibly impaired the vasodilatatory response in the microcirculation but the endothelial-independent vasodilator response to nitroglycerine remained irreversibly lower in healthy aged women.

Asunto(s)

Dislipidemias/sangre , Hipercolesterolemia/fisiopatología , Microcirculación , Adulto , Factores de Edad , Anciano , Antropometría , Velocidad del Flujo Sanguíneo , Colesterol/sangre , Colesterol/metabolismo , LDL-Colesterol/metabolismo , Eritrocitos/citología , Femenino , Humanos , Hipercolesterolemia/sangre , Hiperemia , Angioscopía Microscópica/métodos , Microscopía por Video/métodos , Nitroglicerina/metabolismo , Pletismografía/métodos , Factores de Riesgo , Factores de Tiempo , Vasodilatación

RESUMEN

AIM: To evaluate changes on venous diameter and perimeter of lower limbs in chronic venous disorder (CVD) patients after different clinical treatments for four weeks. METHODS: Fifty-two female patients classified as C2,s or C2,3,s (CEAP classification) were allocated consecutively in three groups: Cirkan (40 mg of the root extract of Ruscus aculeatus + 100 mg of flavonoid hesperidine methylchalcone + 200 mg of vitamin C per pill); elastic compression stockings (ECS) and no treatment (NT). Diameters were determined by duplex ultrasound and perimeter with Leg-O-Meter. RESULTS: After treatment, Cirkan significantly decreased popliteal vein and great saphenous vein (GSV) diameters bilaterally and ECS decreased popliteal vein diameter bilaterally and GSV and varices only on the left limb. Perimeters changed only with ECS. Clinical scores changed between Cirkan x NT and ECS x Cirkan. Disability score varied for ECS x NT and Cirkan x NT. chi2 test detected different distribution frequency for C3 and C2 classes according to treatment: ECS (both limbs) and Cirkan (only left limb). Varices and anatomical scores did not change. CONCLUSIONS: ECS emerges as the most effective clinical treatment tested but improvements with Cirkan on vein diameter and CEAP class were also observed. Clinical scores improved due to pain relief and edema reduction (ECS). These findings point to a positive effect of Cirkan, suggesting that venotonic drugs should be taken into account in the treatment of CVD.

Asunto(s)

Antropometría , Ácido Ascórbico/uso terapéutico , Fármacos Cardiovasculares/uso terapéutico , Quimotripsina/uso terapéutico , Hesperidina/uso terapéutico , Extremidad Inferior/irrigación sanguínea , Extremidad Inferior/patología , Fitosteroles/uso terapéutico , Vena Poplítea/diagnóstico por imagen , Vena Safena/diagnóstico por imagen , Medias de Compresión , Tripsina/uso terapéutico , Ultrasonografía Doppler Dúplex , Enfermedades Vasculares/terapia , Adulto , Antropometría/instrumentación , Ácido Ascórbico/efectos adversos , Brasil , Fármacos Cardiovasculares/efectos adversos , Distribución de Chi-Cuadrado , Enfermedad Crónica , Quimotripsina/efectos adversos , Evaluación de la Discapacidad , Combinación de Medicamentos , Femenino , Hesperidina/efectos adversos , Humanos , Persona de Mediana Edad , Dolor/etiología , Dolor/prevención & control , Dimensión del Dolor , Fitosteroles/efectos adversos , Factores de Tiempo , Resultado del Tratamiento , Tripsina/efectos adversos , Enfermedades Vasculares/complicaciones , Enfermedades Vasculares/diagnóstico por imagen , Enfermedades Vasculares/patología

RESUMEN

AIMS: Insulin resistance and a parental history of diabetes mellitus are independently associated with endothelial dysfunction. Oxidative stress has a pivotal role in the pathophysiology of vascular injury. Metformin, in addition to its glucose-lowering properties, has vasculoprotective effects. We investigated whether metformin has beneficial effects on the nutritive skin capillary circulation and deceases oxidative stress in a group at high risk for Type 2 diabetes mellitus (T2DM) and cardiovascular disease. METHODS: Thirty normoglycaemic subjects with the metabolic syndrome (MS),who had first-degree relatives with T2DM, participated. The mean age was 39.1 +/- 8.4 years and body mass index (BMI) 35.7 +/- 4.8 kg/m2 (mean +/- SD). SUBJECTS: were randomized 1 : 1 to receive placebo (n=14) or metformin (n=16; 1700 mg/day) in a double-blind study. At baseline and post treatment, blood and urine samples were collected for biochemical and 8-epi-prostaglandin F2alpha (8-epi-PGF2alpha) analysis, respectively. Microcirculation was assessed by nailfold videocapillaroscopy, analysing afferent (AF), efferent (EF) and apical (AP) diameters of capillary loops, functional capillary density (FCD), red blood cell velocity at rest (RBCV), after 1 min arterial occlusion (RBCVmax) and time (TRBCVmax)taken to reach it. RESULTS: Groups did not differ significantly in anthropometric, clinical, laboratory or microvascular measurements at baseline. In the metformin group, weight,BMI, systolic blood pressure and fasting plasma glucose fell, and lipid profile and microcirculatory parameters FCD, AF, EF, AP, RBCVmaxand TRBCVmax improved (all P<0.01). No relationship between clinico-laboratory parameters and microvascular reactivity was observed, except for changes in total and low density lipoprotein-cholesterol and RBCVmax* 8-epi-PGF2alpha did not change significantly in either group. CONCLUSIONS: Metformin improved skin capillary reactivity in normoglycaemic MS subjects independently of significant changes in 8-epi-PGF2alpha levels.

Asunto(s)

Enfermedad Coronaria/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Angiopatías Diabéticas/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Síndrome Metabólico/complicaciones , Metformina/uso terapéutico , Adulto , Capilares , Método Doble Ciego , Femenino , Humanos , Masculino , Microcirculación/fisiología , Persona de Mediana Edad , Estrés Oxidativo/fisiología , Factores de Riesgo , Piel/irrigación sanguínea

RESUMEN

Nailfold videocapillaroscopy was performed in 21 controls (C) and 21 patients (P) with systemic lupus erythematosus (SLE) classified according to the American College of Rheumatology, with, at least, 1 year of diagnosed disease and having low activity (MEX-SLEDAI) and sequel (SLICC) indexes at the time of the examination, paired by sex and age. Red blood cell velocity (RBCV, mm/s) at rest and after the release of 60s arterial occlusion (RBCVmax, mm/s), time to reach it (TRBCVmax, s), functional capillary density (FCD, number of capillaries /mm2), afferent, apical and efferent capillary diameters (microm) (DAF, DAP and DEF, respectively) were obtained from videotapes analyzed by the CapImage software. The results did not show any significant difference between the groups that were analyzed, suggesting that morphological (capillary diameters) and functional (RBCV, RBCVmax, TRBCVmax and FCD) parameters are not affected by SLE when low activity and sequel indexes of the disease are present.

Asunto(s)

Capilares/patología , Lupus Eritematoso Sistémico/fisiopatología , Uñas/irrigación sanguínea , Adulto , Viscosidad Sanguínea , Capilares/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad

RESUMEN

OBJECTIVES: To evaluate microcirculatory changes (functional and morphological) in primary antiphospholipid syndrome (PAPS) patients. METHODS: Thirty-one patients were examined using nailfold videocapillaroscopy (18 PAPS patients and 13 healthy subjects). The patients were subdivided into two subgroups, with lupus anticoagulant (n = 8) and with anticardiolipin (n = 10) antibodies. Capillary morphology was determined; diameters ( micro m) and functional capillary density (FCD, number capillaries/mm2) were measured in control conditions. Blood flow velocity (CBFV, mm/s) was also evaluated at rest and after release of 60 s arterial occlusion. RESULTS: The percentage of subjects with at least one morphological alteration in the observed capillaries was 77.8% for patients and 21.3% for healthy subjects. Capillary diameters ( microm) [afferent (AD), apical (APD) and efferent (ED)] were significantly smaller (mean +/- s.d.: AD-PAPS, 7.4 +/- 2.1; control, 9.1 +/- 2.6, P = 0.063; APD-PAPS, 11.6 +/- 2.3; control, 14.4 +/- 3.8, P = 0.015; ED-PAPS, 8.4 +/- 2.0; control, 10.9 +/- 3.2, P = 0.011) in PAPS patients compared with controls. FCD (PAPS, 8.5 +/- 3.2; control, 8.3 +/- 2.9, P +/- 0.862), mean resting CBFV (PAPS, 0.73 +/- 0.31; control, 0.88 +/- 0.41, P = 0.278), mean peak CBFV after occlusion (PAPS, 1.07 +/- 0.52; control, 1.59 +/- 0.91, P = 0.063) and mean time (s) to reach it (PAPS, 5.2 +/- 1.7; control, 4.6 +/- 1.8, P = 0.101) were not statistically different between the two groups. CONCLUSION: Our results suggest that nailfold capillary morphology is altered in patients with PAPS, but these changes could not be correlated to impairment of functional parameters.

Asunto(s)

Síndrome Antifosfolípido/fisiopatología , Capilares/patología , Uñas/irrigación sanguínea , Adulto , Anticuerpos Anticardiolipina/análisis , Síndrome Antifosfolípido/inmunología , Síndrome Antifosfolípido/patología , Velocidad del Flujo Sanguíneo/fisiología , Humanos , Inhibidor de Coagulación del Lupus/análisis , Microcirculación/fisiopatología

RESUMEN

The heterogeneity of regional pulmonary blood flow (RPBF) can be assessed by fractal analysis. The fractal dimension (FD) is a scale-independent measure of spatial heterogeneity of blood flow. The relative dispersion (RD) is often used to obtain the heterogeneity of RPBF but it is influenced by the resolution of measurement. The Blood Flow Analysis (BFA) System was developed in Delphi to represent the three-dimensional structure of lung blood flow and calculates statistics of FD, RD, spatial correlation of neighbored tissue samples and shows histograms of blood flows at diverse time points during different experiments. The BFA System reads a text file with flows, measured with fluorescent microsphere technique, and constructs the lung anatomy with volumetric pixels showing the flows with a color schema. It is possible to rotate the lungs into two axis (XY) and the statistics are shown with 3D graphics. The System maintains a database with data from various studies at same time. The BFA System was validated with four data sets from previous experiments. The BFA System has shown consistency and it is a new tool to help researchers during lung perfusion studies.

Asunto(s)

Circulación Pulmonar , Programas Informáticos , Animales , Colorantes Fluorescentes , Fractales , Pulmón/anatomía & histología , Pulmón/irrigación sanguínea , Microesferas , Modelos Cardiovasculares , Flujo Sanguíneo Regional

RESUMEN

This paper presents a knowledge-based decision support system to assist mechanical ventilation in patients with the Adult Respiratory Distress Syndrome (DSSARDS). The knowledge base uses clinical algorithms developed from interviews and seminars with experts. The system contains 140 rules, applies backward chaining and was built on an IBM-PC compatible microcomputer. Clinical and physiological data and ventilator settings were used for suggestions of ventilatory support mode (VSMODE) and settings (MVSET) and for hemodynamic evaluation and therapy (HEMO). Success rates (s) and kappa coefficient (k) were used to measure agreement between DSSARDS and physicians at 4 decision steps related to: beginning of mechanical ventilation (FIRSTSET), VSMODE, MVSET and HEMO, DSSARDS prototype was evaluated in a development phase with 6 patients aged 48.6 +/- 15.9 years. Agreement results for 142 decision steps were: FIRSTSET k = 0.90, s = 0.93; VSMODE k = 0.76, s = 0.92; HEMO k = 0.58, s = 0.70, MVSET k = 0.86, s = 0.92 (p < 0.05 for all k). Improvements in the knowledge base were performed mainly in HEMO and VSMODE modules. The subsequent test phase studied 5 patients aged 54.8 +/- 11.0 years in a total of 900 decision steps. Results were: FIRSTSET k = 0.93, s = 0.95; VSMODE k = 0.93, s = 0.96; HEMO k = 0.97, s = 0.99, MVSET k = 0.96, s = 0.97 (p < 0.05 for all k). The results indicate significant agreement between DSSARDS and physicians for all decision steps. This suggests that DSSARDS may be used as a support for decision making and a training tool for mechanical ventilation in patients with the adult respiratory distress syndrome.

Asunto(s)

Inteligencia Artificial , Sistemas de Apoyo a Decisiones Clínicas , Respiración Artificial , Síndrome de Dificultad Respiratoria/terapia , Adulto , Sistemas Especialistas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Teóricos