Clinical Physiology and Functional Imaging最新文献

Skin tissue holds a prominent role in microcirculatory research as an easily accessible vascular bed for the noninvasive evaluation of microvascular function. Skin microvascular changes have been associated to alterations in distinct target organs and vascular beds, reinforcing the hypothesis that skin microcirculation can be used as a model of generalized microvascular function. In addition, skin microvascular dysfunction has been documented in cardiovascular disease and patients of increased cardiovascular risk where it has been associated with multiple cardiovascular risk factors, rendering it a candidate surrogate marker of vascular damage. Laser speckle contrast imaging (LSCI) is a noninvasive, dynamic laser technique that allows assessment of skin microvascular function (SMF) by obtaining two-dimensional maps of the skin perfusion in real time with high spatial and temporal resolution and, most importantly, with the highest reproducibility compared to other laser methods. An ever-increasing number of studies using LSCI is confirming evidence of impaired SMF in several cardiovascular risk groups, therefore expanding its application in microvascular research and showing its potential clinical utility. This review attempts to present the growing importance of SMF in cardiovascular research and the emergence of LSCI technique as a robust imaging modality with a promising role to explore skin microvascular physiology. After a short description of the relevant technique and its main principle of function, we have also opted to present the most up to date studies using LSCI for the investigation of SMF in patients with cardiovascular disease as well as various groups of increased cardiovascular risk.

Chronic kidney disease (CKD) is a major population disease. In diabetes as well as hypertension, kidney disease is one of the most serious complications. Recent research has demonstrated that chronic hypoxia is a key actor in the pathogenesis of CKD. In this review, we focus on how functional magnetic resonance imaging (fMRI) techniques can shed light on pathogenetic mechanisms and monitor new treatments aimed at preventing or ameliorating the disease. Multiparametric MRI techniques can measure changes in renal artery flow, tissue perfusion, and oxygenation repetitively over short time periods, enabling high time resolution. Furthermore, renal fibrosis can be quantified noninvasively by MRI diffusion tensor imaging, and techniques are upcoming to measure renal oxygen consumption. These techniques are all radiation and contrast-free.

We briefly present data, demonstrating that fMRI techniques can play a major role in future research in CKD, and possibly also in daily clinical practice.

Breast cancer (BC) is the most common type of cancer among women. Radiotherapy (RT) is one of the main and primary treatment options for BC, especially in breast-conserving surgery (BCS). BC patients who underwent RT experience a wide range of symptoms, in which breast oedema and irritation of the skin take the lion's share. Breast oedema/lymphedema, which is also a prominent side effect after RT should be well determined in earlier settings due to the chronicity of lymphedema. Therefore, this study aimed to analyze the biophysical parameters of skin on the ipsilateral (IL) and contralateral (CL) sites via Tissue dielectric constant (TDC) and Transepidermal water loss (TEWL) methods in terms of oedema and skin barrier function (SBF). The following reference points before and after the RT were measured: (R1: Pectoralis muscle, R2: Upper breast, R3: Lower breast, R4: Lateral site of the thorax). A total of 24 BC patients (mean age and BMI: 52.78 ± 9.85 years and 28.42 ± 5.64 kg/m²) were evaluated. In the IL site, the SBF was not found significant in R1-R3, whereas significantly lower SBF was observed in R4 after RT (t = −3.361, p = 0.003). A significant increase in TDC was observed in R2 at the 5.0 mm depth (t = −2.500, p = 0.02). We suggest that a longer period of follow-up should be carefully carried out to track changes in terms of SBF and oedema in the irradiated breast. The increased need for early detection of changes associated with breast lymphedema can be achievable via noninvasive, safe, cheap, and easily repeatable devices.

The purpose of this study was to determine if muscle growth mediates increases in a strength task which was not directly trained. One hundred fifty-one participants were randomized into control, one-repetition maximum training (1RM-TRAIN), or traditional training (TRAD-TRAIN). Training groups performed isotonic elbow flexion 3x/week for 6 weeks. Anterior muscle thickness at 50%, 60% and 70% upper arm length, and maximal isokinetic torque at 60°/sec were assessed pre- and post-training. Change-score mediation models (adjusted for sex, pre-muscle thickness, and pre-strength) were constructed for each muscle thickness site. The effects of each training group were evaluated relative to the control. Data is presented as coefficient (95% CI). There were no significant relative direct effects on nonspecific strength for either training group outside of the 60% model (1.7 [0.13, 3.27] Nm). The relative effect of 1RM-TRAIN on muscle thickness was greater in 60% (0.09 [0.01, 0.17] cm) and 70% (0.09 [0.00, 0.17] cm) models; while TRAD-TRAIN was greater in all three: (50% = 0.24 [0.15, 0.32]; 60% = 0.24 [0.16, 0.33]; 70% = 0.22 [0.14, 0.31] cm). The effect of muscle thickness on nonspecific strength was only significant for the 60% (−3.06 [−5.7, −0.35] Nm) model. The relative indirect effect on nonspecific strength was not significant for the 1RM-TRAIN or TRAD-TRAIN. Similar to previous findings on specific strength, we did not find evidence for a mediating effect of muscle growth on training induced increases in nonspecific strength. The importance of muscle growth for changes in nonspecifically trained strength may need to be reconsidered.