Optical Instrumentation for the Measurement of Blood Perfusion, Concentration, and Oxygenation in Living Microcirculation

2011 ◽  
pp. 573-604 ◽  
Author(s):  
Martin J. Leahy ◽  
Jim O'Doherty
Keyword(s):  
Blood Perfusion ◽  
Optical Instrumentation

Partition Coefficient Ratios and Tumour Perfusion Studied with 85mKr and 133Xe

1987 ◽  
Vol 26 (06) ◽  
pp. 253-257
Author(s):  
M. Mäntylä ◽  
J. Perkkiö ◽  
J. Heikkonen
Keyword(s):  
Partition Coefficient ◽  
Partition Coefficients ◽  
Regional Blood Flow ◽  
Blood Perfusion ◽  
Compartmental Analysis ◽  
Malignant Tumour ◽  
Mean Value ◽  
Perfusion Rate ◽  
Biological Variables ◽  
The Mean

The relative partition coefficients of krypton and xenon, and the regional blood flow in 27 superficial malignant tumour nodules in 22 patients with diagnosed tumours were measured using the 85mKr- and 133Xe-clearance method. In order to minimize the effect of biological variables on the measurements the radionuclides were injected simultaneously into the tumour. The distribution of the radiotracers was assumed to be in equilibrium at the beginning of the experiment. The blood perfusion was calculated by fitting a two-exponential function to the measuring points. The mean value of the perfusion rate calculated from the xenon results was 13 ± 10 ml/(100 g-min) [range 3 to 38 ml/(100 g-min)] and from the krypton results 19 ± 11 ml/(100 g-min) [range 5 to 45 ml/(100 g-min)]. These values were obtained, if the partition coefficients are equal to one. The equations obtained by using compartmental analysis were used for the calculation of the relative partition coefficient of krypton and xenon. The partition coefficient of krypton was found to be slightly smaller than that of xenon, which may be due to its smaller molecular weight.

Repurposing cilostazol for Raynaud's phenomenon

2020 ◽  
Vol 27 ◽  
Author(s):  
Nehme El-Hachem ◽  
Manal M. Fardoun ◽  
Hasan Slika ◽  
Elias Baydoun ◽  
Ali H. Eid
Keyword(s):  
Color Change ◽  
Angiotensin Receptor Blockers ◽  
Raynaud’S Phenomenon ◽  
Blood Perfusion ◽  
Raynaud's Phenomenon ◽  
Channel Blockers ◽  
Phosphodiesterase Type 5 Inhibitors ◽  
Receptor Blockers ◽  
Phosphodiesterase Type ◽  
Food And Drugs Administration

: Raynaud's Phenomenon (RP) results from exaggerated cold-induced vasoconstriction. RP patients suffer from vasospastic attacks and compromised digital blood perfusion leading to triple color change at the level the fingers. Severe RP may cause ulcers and threaten tissue viability. Many drugs have been used to alleviate the symptoms of RP. These include calcium-channel blockers, cGMP-specific phosphodiesterase type 5 inhibitors, prostacyclin analogs, and angiotensin receptor blockers. Despite their variety, these drugs do not treat RP but rather alleviate its symptoms. To date, no drug for RP has been yet approved by U.S Food and Drugs Administration. Cilostazol is a selective inhibitor of phosphodiesteraseIII, originally prescribed to treat intermittent claudication. Owing to its antiplatelet and vasodilating properties, cilostazol is being repurposed as a potential drug for RP. This review focuses on the different lines of action of action of cilostazol serving to enhance blood perfusion in RP patients.

scholarly journals Oxygen-Sensitivity and Pulmonary Selectivity of Vasodilators as Potential Drugs for Pulmonary Hypertension

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 155
Author(s):  
Daniel Morales-Cano ◽  
Bianca Barreira ◽  
Beatriz De Olaiz Navarro ◽  
María Callejo ◽  
Gema Mondejar-Parreño ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Gas Exchange ◽  
Pulmonary Circulation ◽  
Pulmonary Arteries ◽  
Blood Perfusion ◽  
Mesenteric Arteries ◽  
Oxygen Sensitivity ◽  
Low Oxygen ◽  
Oxygen Selectivity

Current approved therapies for pulmonary hypertension (PH) aim to restore the balance between endothelial mediators in the pulmonary circulation. These drugs may exert vasodilator effects on poorly oxygenated vessels. This may lead to the derivation of blood perfusion towards low ventilated alveoli, i.e., producing ventilation-perfusion mismatch, with detrimental effects on gas exchange. The aim of this study is to analyze the oxygen-sensitivity in vitro of 25 drugs currently used or potentially useful for PH. Additionally, the study analyses the effectiveness of these vasodilators in the pulmonary vs. the systemic vessels. Vasodilator responses were recorded in pulmonary arteries (PA) and mesenteric arteries (MA) from rats and in human PA in a wire myograph under different oxygen concentrations. None of the studied drugs showed oxygen selectivity, being equally or more effective as vasodilators under conditions of low oxygen as compared to high oxygen levels. The drugs studied showed low pulmonary selectivity, being equally or more effective as vasodilators in systemic than in PA. A similar behavior was observed for the members within each drug family. In conclusion, none of the drugs showed optimal vasodilator profile, which may limit their therapeutic efficacy in PH.

scholarly journals Mechanisms of Venoarteriolar Reflex in Type 2 Diabetes with or without Peripheral Neuropathy

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 333
Author(s):  
Cécile Reynès ◽  
Antonia Perez-Martin ◽  
Houda Ennaifer ◽  
Henrique Silva ◽  
Yannick Knapp ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Peripheral Neuropathy ◽  
Spectral Power ◽  
Blood Perfusion ◽  
Doppler Flowmetry ◽  
Relative Contribution ◽  
Total Spectral Power ◽  
Underlying Mechanisms ◽  
Endothelial Nitric Oxide

The aim of this study is to investigate the underlying mechanisms of the venoarteriolar reflex (VAR) in type 2 diabetes mellitus (T2DM), with and without peripheral neuropathy. Laser Doppler flowmetry (LDF) recordings were performed on the medial malleus and dorsal foot skin, before and during leg dependency in healthy controls, in persons with obesity, in those with T2DM, in those with T2DM and subclinical neuropathy, and in those with T2DM and confirmed neuropathy. LDF recordings were analyzed with the wavelet transform to evaluate the mechanisms controlling the flowmotion (i.e., endothelial nitric oxide-independent and -dependent, neurogenic, myogenic, respiratory and cardiac mechanisms). Skin blood perfusion decreased throughout leg dependency at both sites. The decrease was blunted in persons with confirmed neuropathy compared to those with T2DM alone and the controls. During leg dependency, total spectral power increased in all groups compared to rest. The relative contribution of the endothelial bands increased and of the myogenic band decreased, without differences between groups. Neurogenic contribution decreased in controls, in persons with obesity and in those with T2DM, whereas it increased in subclinical- and confirmed neuropathy. In conclusion, this study provides evidence that confirmed diabetic neuropathy alters the VAR through the neurogenic response to leg dependency.

scholarly journals Intermedin facilitates hepatocellular carcinoma cell survival and invasion via ERK1/2-EGR1/DDIT3 signaling cascade

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fei Xiao ◽  
Hongyu Li ◽  
Zhongxue Feng ◽  
Luping Huang ◽  
Lingmiao Kong ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Er Stress ◽  
Cell Survival ◽  
Vascular Remodeling ◽  
Therapeutic Potential ◽  
Blood Perfusion ◽  
Signaling Cascade ◽  
Apoptotic Pathway ◽  
High Level ◽  
Hcc Cells

AbstractAs one of the most malignant cancer types, hepatocellular carcinoma (HCC) is highly invasive and capable of metastasizing to distant organs. Intermedin (IMD), an endogenous peptide belonging to the calcitonin family, has been suggested playing important roles in cancer cell survival and invasion, including in HCC. However, how IMD affects the behavior of HCC cells and the underlying mechanisms have not been fully elucidated. Here, we show that IMD maintains an important homeostatic state by activating the ERK1/2-EGR1 (early growth response 1) signaling cascade, through which HCC cells acquire a highly invasive ability via significantly enhanced filopodia formation. The inhibition of IMD blocks the phosphorylation of ERK1/2, resulting in EGR1 downregulation and endoplasmic reticulum stress (ER) stress, which is evidenced by the upregulation of ER stress marker DDIT3 (DNA damage-inducible transcript 3). The high level of DDIT3 induces HCC cells into an ER-stress related apoptotic pathway. Along with our previous finding that IMD plays critical roles in the vascular remodeling process that improves tumor blood perfusion, IMD may facilitate the acquisition of increased invasive abilities and a survival benefit by HCC cells, and it is easier for HCC cells to obtain blood supply via the vascular remodeling activities of IMD. According to these results, blockade of IMD activity may have therapeutic potential in the treatment of HCC.

scholarly journals Efficacy of topical and systemic transplantation of mesenchymal stem cells in a rat model of diabetic ischemic wounds

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jianxin Yan ◽  
Jiaji Liang ◽  
Yingxuan Cao ◽  
Mariya M. El Akkawi ◽  
Xuan Liao ◽  
...  
Keyword(s):  
Stem Cells ◽  
Wound Healing ◽  
Mesenchymal Stem Cells ◽  
Chronic Wounds ◽  
Blood Perfusion ◽  
Systemic Administration ◽  
Critical Parameters ◽  
Administration Routes ◽  
Positive Effects ◽  
Systemic Treatments

Abstract Background Mesenchymal stem cells (MSCs) exert positive effects in chronic wounds. However, critical parameters, such as the most effective administration routes, remain unclear. Accordingly, the purpose of this study was to compare the effects of topical and systemic transplantation MSCs on diabetic ischemic wound healing and explored the underlying mechanisms. Method A diabetic ischemic wound model was created on the dorsal foot of type 2 diabetes mellitus (T2DM) rat. Bone marrow-derived mesenchymal stem cells (BM-MSCs) were administered via two routes: topical injection and intravenous (IV) infusion. Wound healing outcomes and blood glucose level were assessed dynamically. Meanwhile, blood flow recovery was evaluated in ischemic gastrocnemius muscles. The homing and transdifferentiation of mKate2-labeled BM-MSCs were assessed by fluorescence imaging and immunohistochemistry (IHC) analysis. Result Both topical and systemic treatments had a positive effect on the diabetic ischemic wound showing a significant reduction in wound area at day 14. Histological results showed an increase in the length of epithelial edges, collagen content, microvessel density in the wound bed, and a higher expression of vascular endothelial growth factor (VEGF). Meanwhile, systemic administration can ameliorate hyperglycemia and improve the blood perfusion of the ischemic hindlimb. BM-MSCs administered systemically were found distributed in wounded tissue and transdifferentiated into endothelial cells. Furthermore, BM-MSCs stimulated angiogenesis at wound sites by downregulating phosphatase and tensin homolog (PTEN) and activation of AKT signaling pathway. Conclusions The results demonstrated that both transplantation delivery method (topical and systemic) of BM-MSCs accelerated wound healing remarkably under pathological conditions. Nevertheless, systemic administration has the potential to ameliorate hyperglycemia and repair the damaged tissue.

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