Relative to normal tissues, tumor microcirculation exhibits high structural and functional heterogeneity leading hypoxic regions impairing treatment efficacy. Here, computational simulations of blood vessel adaptation are used explore the hypothesis that abnormal adaptive responses local hemodynamic metabolic stimuli contribute aberrant morphological characteristics microcirculation. Topology, vascular diameter, length, red cell velocity mesenteric networks were recorded by intravital...

Myogenic response, flow-dependent dilation, and direct metabolic control are important mechanisms controlling coronary flow. A model was developed to study how these interact at different locations in the arteriolar tree evaluate their contribution autoregulatory flow control. The consists of 10 resistance compartments series, each representing parallel vessel units, with diameters determined by tone depending on either pressure [flow-dependent reduction factor (TRF ) × Tone myo ] or...

Mechanical properties of the extracellular matrix (ECM) play a key role in tissue organization and morphogenesis. Rheological jellyfish ECM (mesoglea) were measured vivo at cellular scale by passive microrheology techniques: microbeads injected their Brownian motion was recorded to determine mechanical surrounding medium. Microrheology results compared with macrorheological measurements performed shear rheometer on slices mesoglea. We found that behaved as viscoelastic gel macroscopic much...

The objectives of this study were to evaluate the myogenic behavior blood vessels and their interaction within coronary arterial tree possible role response in autoregulation. model consists 10 compartments series, each representing a class vessel sizes. Diameter resistance are determined by value at full dilation (d(p,) R(p)) response. Three distributions R(p) three strength, M(i) (slope pressure-diameter curve, range -0.05 -0.4%/mmHg) evaluated (9 cases). It was found that larger attenuate...

Varying coronary volume will vary vascular resistance and thereby have an effect on hemodynamics. Six ventricular septa were isolated from anesthetized dogs, dispersed in a biaxial stretch apparatus at diastolic stress, perfused artificially with oxygenated perfluorochemical emulsion maximal vasodilation. Flow thickness measured continuously by electromagnetic flow probe sonomicrometer. Pressure was varied sinusoidally around 30, 50, 70 mmHg amplitude of 7.5 mmHg; frequencies ranged between...

How vascular systems and their respiratory pigments evolved is still debated. While many animals present a system, hemoglobin exists as blood pigment only in few groups (vertebrates, annelids, arthropod mollusk species). Hemoglobins are formed of globin sub-units, belonging to multigene families, various multimeric assemblages. It was so far unclear whether families from different bilaterian had common origin.

Patterns in biology can be considered as predetermined or arising from a self-organizing instability. Variability the pattern can, thus, interpreted trace of instability, growing out noise. Studying this variability hint toward an underlying morphogenetic mechanism. Here, we present gastrovascular system jellyfish Aurelia . In emerges typical biased reconnection between canals and time-correlated reconnections. Both phenomena traces mechanistic effects, swimming contractions on tissue...

Transport networks, such as vasculature or river provide key functions in organisms and the environment. They usually contain loops whose significance for stability robustness of network is well documented. However, dynamics their formation not considered. Such structures often grow response to gradient an external field. During evolution, extending branches compete available flux field, which leads effective repulsion between them screening shorter ones. Yet, remarkably diverse processes,...

Pulmonary vasoconstriction in response to alveolar hypoxia (HPV) is frequently impaired patients with sepsis or acute respiratory distress syndrome animal models of endotoxemia. vasodilation due overproduction nitric oxide (NO) by NO synthase 2 (NOS2) may be responsible for this HPV after administration endotoxin (LPS). We investigated the effects nonspecific (N(G)-nitro-L-arginine methyl ester, L-NAME) and NOS2-specific [L-N6-(1-iminoethyl)lysine, L-NIL] NOS inhibition congenital deficiency...

The adult vasculature is comprised of three distinct compartments: the arteries, which carry blood away from heart and display a divergent flow pattern; capillaries, where oxygen nutrient delivery to tissues, as well metabolic waste removal, occurs; veins, back are characterized by convergent pattern. These compartments organized in series regard flow, proceeds upstream arteries downstream veins through capillaries. However, spatial organization more complex, may often be found paralleling...

It is getting increasingly evident that physical properties such as elastoviscoplastic of living materials are quite important for the process tissue development, including regulation genetic pathways. Measuring in vivo a complicated and challenging task. In this paper, we present an instrument, scanning air puff tonometer, which able to map point by viscoelastic flat or gently curved soft materials. This instrument improved version tonometer used optometrists, with modifications. The allows...

During embryonic development, most organs are in a state of mechanical compression because they grow confined and limited amount space within the embryo's body; early gut is an exception it physiologically herniates out coelom. We demonstrate here that physiological hernia caused by tensile force transmitted vitelline duct on loop at its attachment point umbilicus. quantify this show applying tension for 48 h induces stress-dependent elongational growth culture, with average 90% length...

Background : Understanding how molecular and physical cues orchestrate vascular morphogenesis is a challenge for developmental biology. Only little attention has been paid to the impact of mechanical stress caused by tissue growth on early blood distribution. Here we study peripheral accumulation in chicken embryonic yolk sac, which precedes sinus vein formation. Results We report that starts before heart‐induced circulation. hypothesized driving force primitive flow growth‐induced gradient...

Cutaneous amyloidosis refers to a rare group of skin disease, which is characterized by the deposition amyloid material. Nodular localized cutaneous (NLCA) rarest type amyloidosis. A 54-year-old woman presented clinic with two lesions on nose. We describe examinations that led diagnosis NLCA and treatment given her. PubMed was used find literature about nodular After carefully weighing different options consulting colleagues, shaving techniques were considered best option for this patient....

To date, investigation of coronary arteriole vasomotor activity has been limited to arterioles >30- 40 microm. Here, we introduce a new experimental model allow for in situ microscopy terminal arterioles.Rat hearts were perfused closed loop system (priming volume 20 ml) which was placed on computer-controlled microscope stage. FITC-dextran and tetrodotoxin (TTX, 50 microM) added. Tilting the by 90 degrees allowed visual access ventricular surface. Arterioles identified flow direction...

We investigated the influence of stretch on regional hemodynamic parameters septal circulation. used a similar experimental setup and mathematical model, as described previously (14). Five ventricular septa were isolated from anesthetized dogs, sutured to biaxial stretching apparatus, perfused with an oxygenated perfluorochemical emulsion at maximal vasodilation. Under unloaded biaxially stretched conditions, flow thickness (to index vascular volume) measured continuously. Pressure was...

Abstract Background How vascular systems and their respiratory pigments evolved is still debated. While many animals present a system, hemoglobin exists as blood pigment only in few groups (Vertebrates, Annelids, Arthropod Mollusk species). Hemoglobins are formed of globin sub-units, belonging to multigene families, various multimeric assemblages. It was so far unclear whether families from different Bilaterian had common origin. Results To unravel evolution Bilaterians, we studied the...

The development of a primitive vascular circuit into hierarchical network involves an interplay between genetic determination and physical self organisation. We investigated the navigation newly sprouting vessels in jellyfish possible contribution mechanical stress involved organization. With microscopic shadowgraphing we observed ~3 months old while lying on its back shallow seawater such that muscle at rim umbrella is able to slightly contract. ‘arteries’ (black) gastrovasculature are...