The purpose of this work is to investigate if the change in plan quality with the finer leaf resolution and lower leakage of the 160 MLC would be dosimetrically significant for head and neck intensity-modulated radiation therapy (IMRT) treat- ment plans. The 160 MLC consisting of 80 leaves of 0.5 cm on each bank, a leaf span of 20 cm, and leakage of less than 0.37% without additional backup jaw...

Turner, J. R., J. M. Angle, E. D. Black, J. L. Joyal, D. B. Sacks, and J. L. Madara. PKC-dependent regulation of transepithelial resistance: roles of MLC and MLC kinase. Am. J. Physiol. 277 (Cell Physiol. 46): C554–C562, 1999.— The mechanisms by which protein kinase C (PKC) activation results in increased transepithelial resistance (TER) are unknown [G. Hecht, B. Robinson, and A. Koutsouris. Am...

Accurate multileaf collimator (MLC) leaf positioning plays an essential role in the effective implementation of intensity modulated radiation therapy (IMRT). This work evaluates the sensitivity of current patient-specific IMRT quality assurance (QA) procedures to minor MLC leaf positioning errors. Random errors of up to 2 mm and systematic errors of +/-1 mm and +/-2 mm in MLC leaf positions wer...

OBJECTIVE The effect of multileaf collimator (MLC) margin on target and normal tissue dose-volume metrics for intracranial stereotactic radiosurgery (SRS) was assessed. METHODS 118 intracranial lesions of 83 SRS patients formed the basis of this study. For each planning target volume (PTV), five separate treatment plans were generated with MLC margins of -1, 0, 1, 2 and 3 mm, respectively. Id...

Muscular lymphatics use both phasic and tonic contractions to transport lymph for conducting their vital functions. The molecular mechanisms regulating lymphatic muscle contractions are not well understood. Based on the well-established finding that the phosphorylation of myosin light chain 20 (MLC(20)) plays an essential role in blood vessel smooth muscle contraction, we investigated if phosph...

Purpose: Motorized or dynamic wedge is routinely used nowadays to facilitate the work and reduce time on the treatment machine. However, this will necessitate keeping the Multileaf collimator (MLC) direction parallel to the chest wall. The aim of our work is to study the effect of Multileaf collimator in the perpendicular (┴) or parallel(//) direction on: target volume coverage, dose homogeneit...

Possible involvement of reversible phosphorylation and dephosphorylation of myosin light chain (MLC) by myosin light chain kinase (MLCK) and protein phosphatases (PPases), respectively, in the Ca++-calmodulin-dependent inhibition of renin secretion was investigated with the use of putative MLCK inhibitor ML-7 [1-(5-iodonaphthalene-1-sulfonyl)-1H-hexahydro-1,4-diazepine] and PPase type1 (PPase-1...

In this study we investigated whether the expression of N-terminal myosin light chain-1 (MLC-1) peptides could improve the intrinsic contractility of the whole heart. We generated transgenic rats (TGR) that overexpressed minigenes encoding the N-terminal 15 amino acids of human atrial MLC-1 (TGR/hALC-1/1-15, lines 7475 and 3966) or human ventricular MLC-1 (TGR/hVLC-1/1-15, lines 6113 and 6114) ...

The importance of Ca 2 /calmodulin-dependent myosin light chain kinase (MLCK) for smooth muscle contraction is well documented.1 Until recently, myosin light chain (MLC) phosphatase was thought to be unregulated and constitutively active. However, studies have demonstrated that smooth muscle contraction is dependent on regulation of MLC phosphatase activity.2,3 The inhibition of phosphatase act...

Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare type of leukodystrophy caused by mutations in either MLC1 or GLIALCAM genes and is associated with myelin and astrocyte vacuolation. It has been suggested that MLC is caused by impaired cell volume regulation as a result of defective activation of astrocytic volume-regulated anion currents (VRAC). GlialCAM brings MLC1 an...