We examined the ability of kinesin to support the movement of adrenal medullary chromaffin granules on microtubules in a defined in vitro system. We found that kinesin and ATP are all that is required to support efficient (33% vesicle motility) and rapid (0.4-0.6 micron/s) translocation of secretory granule membranes on microtubules in the presence of a low-salt motility buffer. Kinesin also in...

Peri-centrosomal positioning of the mammalian Golgi apparatus is known to involve microtubule-based motility, but its importance for cellular physiology is a major unanswered question. Here, we identify golgin-160 and GMAP210 as proteins required for centripetal motility of Golgi membranes. In the absence of either golgin, peri-centrosomal positioning of the Golgi apparatus was disrupted while ...

achalasia is a primary motor disorder of the esophagus, in which esophageal emptying is impaired. diagnosis of achalasia is based on clinical findings and confirmed by radiologic, endoscopic and manometric evaluations. several treatments for achalasia have been introduced. we searched the pubmed database for original articles and meta-analyses about achalasia to summarize the current knowledge ...

the swim-up procedure was used to collect a sperm fraction with improved motility and normal morphology from fertile and infertile semen samples. the untreated and swim-up fractions were analyzed with the hamilton-thorn motility analyser. comparisons were made to see the effect of this sperm selection technique on sperm motility and morphology. they were then examined by transmission electron m...

We propose a mechanism of cell motility which places emphasis on contraction while ignoring treadmilling. At the basis of the model is contraction driven uphill diffusion destabilizing symmetric configuration and causing polarization. The morphological instability is due to spontaneous internal motion of the cytoskeleton which is generated by active cross-linkers and simultaneously transports t...

We propose a mechanism of cell motility which is based on contraction and does not require protrusion. The contraction driven translocation of a cell is due to internal flow of the cytoskeleton generated by molecular motors. Each motor contributes to the stress field and simultaneously undergoes biased random motion in the direction of a higher value of this stress. In this way active cross-lin...

We simulate with hydrodynamics a suspension of active disks squirming through a Newtonian fluid. We explore numerically the full range of squirmer area fractions from dilute to close packed and show that "motility induced phase separation," which was recently proposed to arise generically in active matter, and which has been seen in simulations of active Brownian disks, is strongly suppressed b...

Purpose: MR enterography (MRE) is one of the mainstays in the evaluation of Crohns disease (CD). A wide variety of studies have attempted to improve the sensitivity and specificity of MRE, all focusing on the evaluation of static images [1]. MRE however allows not only the static display of morphology, but can be combined with ultrafast scanning techniques (cineMRE) for analysis of bowel motili...

Burkholderia glumae is a plant pathogenic bacterium that uses an acyl-homoserine lactone-mediated quorum sensing system to regulate protein secretion, oxalate production and major virulence determinants such as toxoflavin and flagella. B. glumae also releases surface-active rhamnolipids. In Pseudomonas aeruginosa and Burkholderia thailandensis, rhamnolipids, along with flagella, are required fo...

The mechanism of bacterial gliding motility (active movement over surfaces without the aid of flagella) is not known. A large number of nonmotile mutants of the gliding bacterium Flavobacterium johnsoniae (Cytophaga johnsonae) have been previously isolated, and genetic techniques to analyze these mutants have recently been developed. We complemented a nonmotile mutant of F. johnsoniae (UW102-09...