Search results for " Microcirculation"

Effects of Essential Hypertension on coronary Microcirculation: Focus on a Population of Hypertensives Affected by Microvascular Angina

2012

A correlation between essential hypertension and the establishmentof myocardial ischemia is nowadays universally accepted. Coronary atherosclerosis is deemed to be the most important process through which the capability of coronary district to supply a blood flow consistent with myocardial needs can be impaired, until the onset of an anginal syndrome. In this study, we verified whether hypertensives’ coronaries, seen by performing an angiographic study, are properly definable as normal, even in presence of an overt exertional angina, or if they should rather be barely defined as “macroscopically unharmed”, through the clues of a microvascular alteration

Experimental evidence for a hyperthermia-induced breakdown of tumor blood flow during normoglycemia

1983

A compilation of experimental data is presented indicating that hyperthermia alone can achieve a significant inhibition of tumor blood flow if appropriate heat exposure times and tissue hyperthermia levels are chosen.

Pathophysiological aspects of hyperthermia

1992

Blood flow in many rapidly growing tumors is sluggish leading to an impairment of convective heat dissipation which facilitates tumor heating compared to normal tissues. In addition, the compromised microcirculation causes a hostile metabolic micromilieu which can modulate the therapeutic effect of heat. After clinically relevant heat doses, a shut-down of tumor microcirculation is often observed creating a “heat-reservoir” and aggravating tumor hypoxia, acidosis, and substrate and energy depletion, factors which are known to greatly enhance tumor cell killing by heat. Since the mechanisms described are mostly derived from experimental results on fast-growing animal tumors, the clinical rel…

Portal hypertension and variceal bleeding: An AASLD single topic symposium

1998

In June 1996, the American Association for the Study of Liver Diseases sponsored a single topic workshop combining a two-day symposium on liver microcirculation in health and diseases1 followed by a two day consensus workshop on portal hypertension and variceal bleeding. The goal of the combined conference was to identify areas of critical importance in the understanding and treatment of portal hypertension and to foster future collaborative research projects. The portal hypertension-variceal bleeding conference consisted of eight panel discussions, each highlighting a specific topic related to evaluation and treatment of portal hypertension. The chair of each panel was charged to summarize…

Role of M1, M3, and M5 muscarinic acetylcholine receptors in cholinergic dilation of small arteries studied with gene-targeted mice

2011

Acetylcholine regulates perfusion of numerous organs via changes in local blood flow involving muscarinic receptor-induced release of vasorelaxing agents from the endothelium. The purpose of the present study was to determine the role of M1, M3, and M5 muscarinic acetylcholine receptors in vasodilation of small arteries using gene-targeted mice deficient in either of the three receptor subtypes (M1R−/−, M3R−/−, or M5R−/− mice, respectively). Muscarinic receptor gene expression was determined in murine cutaneous, skeletal muscle, and renal interlobar arteries using real-time PCR. Moreover, respective arteries from M1R−/−, M3R−/−, M5R−/−, and wild-type mice were isolated, cannulated with mic…

Rapid palatal expansion: the role of microcirculation

2015

Transverse palate modifications fall under expansive orthopedic therapy of the upper maxilla. The only practical approach to the problem on the transverse plane is that of performing the expansion of the maxillary arch through an opening of the median palatal suture. It is important to understand the changes of the vascular network in midpalatal suture following the starting of rapid maxillary expansion. It is critical to maintain the blood supply and circulation for the osteogenesis and bone remodeling after the expansion. The aim of this research was to evaluate the effects of rapid orthopedic expansion (REP) at the microcirculatory level through capillaroscopic examination. METHODS: Fift…

Tako-tsubo cardiomyopathy and microcirculation.

2010

Takotsubo cardiomyopathy was described for the first time in Japan in the 1990s. It is very similar to the ischemic cardiopathy both for clinical and instrumental characteristics. His peculiarity is an alteration of the ventricular contraction mechanism with hypo-akinesis of the apex and lateral segments of the left ventricle, associated with hyper-kinesis of the heart base which is responsible for the typical echocardiographic aspect of a cruet during the systole. However, the etiology of this cardiomyopathy is still unknown despite the fact that numerous hypothesis have been made. A single study of 16 patients proved multivasal damage by a BLASH SCORE analysis of the coronary radiography.…

MR-Perfusionsbildgebung des Herzens mit TrueFISP

2001

OBJECTIVE Development and test of a saturation-recovery TrueFISP (SR-Trufi) pulse sequence for myocardial perfusion MR imaging (MRI) using improved gradient hardware. MATERIAL AND METHODS Measurements were performed on a 1.5 T scanner with prototype gradients (50 mT/m, minimum rise time 300 microseconds). T1-weighted first-pass MRI of Gd-DTPA (0.025 mumol/kg) kinetics in the myocardium was performed using an SR-Trufi pulse sequence (TR/TE/alpha = 2.6 ms/1.4 ms/55 degrees) with a saturation preparation of TD = 30 ms before the TrueFISP readout. Measurements were performed in volunteers (n = 4) and in a pig model of chronic ischemia (n = 1). RESULTS In phantoms, the signal intensity was linea…

Sevoflurane-induced reduction of bispectral index does not affect human cerebral microcirculation

2015

Changes of oral microcirculation in chemotherapy patients: A possible correlation with mucositis?

2014

The aim of this investigation is to appraise labial oral microcirculation in chemotherapy patients to clarify the effects of cytotoxic agents on oral microvessels. Twenty-five patients with diagnosis of head and neck tumors were recruited in the study. All the patients were submitted to chemotherapy. Labial oral microcirculation was evaluated on labial mucosa using oral videocapillaroscopy. The statistical significance was checked with the Mann-Whitney U-test (P < 0.05). The analysis of videocapillaroscopic patterns showed statistically significant variations relative to the diameter of the incoming loop; the diameter of the outgoing loop; and loop tortuosity. This study shows that capillar…