The reliability of quantitative evaluation by doppler ultrasound with regard to the ophthalmic collateral blood flow in patients with carotid artery occlusion was estimated. The ultrasonic doppler flow signals of the ophthalmic collateral flow of 54 carotid occlusions were classified into four types and three degrees--high, moderate, and low reversed flow patterns--and were compared with the an...

Coronary collaterals may not be apparent during routine coronary angiography or during coronary angioplasty as a result of a variety of physiologic and anatomic factors.‘-” The dynamic nature of the collateral circulation has been demonstrated by newly appearing angiographic collaterals during contralateral vessel occlusion.3 An elevated coronary occlusion wedge pressure during angioplasty ball...

BACKGROUND AND PURPOSE To evaluate the potential of a new dynamic MRA sequence (DynAngio) based on arterial spin labeling for the assessment of intracranial collateral flow. METHODS Twelve patients with unilateral internal carotid artery obstruction were investigated. Different patterns of collateral flow were compared between DynAngio, transcranial color-coded duplex ultrasound, and time-of-...

Previous studies established different responses between proximal and distal portions of Schaffer collateral axons during high-frequency and burst stimulation, with distal axons demonstrating biphasic changes in excitability (hyperexcitability followed by depression), but proximal axons showing only monophasic depression. Voltage-dependent potassium (KV) channels are important determinants of a...

Collateral remodeling is critical for blood flow restoration in peripheral arterial disease and is triggered by increasing fluid shear stress in preexisting collateral arteries. So far, no arterial-specific mediators of this mechanotransduction response have been identified. We show that muscle segment homeobox 1 (MSX1) acts exclusively in collateral arterial endothelium to transduce the extrin...

BACKGROUND The validity of self-report data is an area of continuing concern in the substance abuse treatment field. It is uncertain how well self-report of alcohol relapse corresponds with more objective indices. METHODS We compared the self-report of alcohol relapse to collateral reports and biological indices of relapse. Twelve-month post-treatment follow-up data were collected from 94 mal...

This paper considers an economy where agents face limited commitment and must transfer a durable asset as collateral to borrow. Rehypothecation allows lenders to re-sell this pledged asset or re-use it as collateral to sustain further borrowing. As such, it increases the ultimate supply of durable asset in the economy along collateralized credit chains. However, limited commitment now affects r...

New drug deployment strategies are imperative to address the problem of drug resistance, which is limiting the management of infectious diseases and cancers. We evolved resistance in Escherichia coli toward 23 drugs used clinically for treating bacterial infections and mapped the resulting collateral sensitivity and resistance profiles, revealing a complex collateral sensitivity network. On the...

Recent clinical and animal studies have shown that collateral artery growth is impaired in the presence of vascular risk factors, including hypertension. Available evidence suggests that angiotensin-converting enzyme inhibitors (ACEI) promote collateral growth in both hypertensive humans and animals; however, the specific mechanisms are not established. This study evaluated the hypothesis that ...

OBJECTIVE Aging is a major risk factor for increased ischemic tissue injury. Whether collateral rarefaction and impaired remodeling contribute to this is unknown. We quantified the number and diameter of native collaterals and their remodeling in 3-, 16-, 24-, and 31-month-old mice. METHODS AND RESULTS Aging caused an "age-dose-dependent" greater drop in perfusion immediately after femoral ar...