scholarly journals Grazing rates on bacteria by marine heterotrophic microflagellates compared to uptake rates of bacterial-sized monodisperse fluorescent latex beads

1988 ◽  
Vol 44 ◽  
pp. 159-165 ◽  
Author(s):  
K Nygaard ◽  
KY Børsheim ◽  
TF Thingstad
Keyword(s):  
Latex Beads ◽  
Uptake Rates ◽  
Heterotrophic Microflagellates

Computing cell tractions from particle displacements on silicone rubber substrata

1994 ◽  
Vol 52 ◽  
pp. 162-163
Author(s):  
Tim Oliver ◽  
Akira Ishihara ◽  
Ken Jacobsen ◽  
Micah Dembo
Keyword(s):  
Plane Stress ◽  
Linear Elasticity ◽  
Silicone Rubber ◽  
Mathematical Analysis ◽  
Elastic Recovery ◽  
Video Images ◽  
Cell Traction Forces ◽  
Latex Beads ◽  
Cell Traction ◽  
Better Than

In order to better understand the distribution of cell traction forces generated by rapidly locomoting cells, we have applied a mathematical analysis to our modified silicone rubber traction assay, based on the plane stress Green’s function of linear elasticity. To achieve this, we made crosslinked silicone rubber films into which we incorporated many more latex beads than previously possible (Figs. 1 and 6), using a modified airbrush. These films could be deformed by fish keratocytes, were virtually drift-free, and showed better than a 90% elastic recovery to micromanipulation (data not shown). Video images of cells locomoting on these films were recorded. From a pair of images representing the undisturbed and stressed states of the film, we recorded the cell’s outline and the associated displacements of bead centroids using Image-1 (Fig. 1). Next, using our own software, a mesh of quadrilaterals was plotted (Fig. 2) to represent the cell outline and to superimpose on the outline a traction density distribution. The net displacement of each bead in the film was calculated from centroid data and displayed with the mesh outline (Fig. 3).

Video-microscopic measurement of cell-substratum traction forces generated by locomoting keratocytes

1993 ◽  
Vol 51 ◽  
pp. 188-189
Author(s):  
Tim Oliver ◽  
Michelle Leonard ◽  
Juliet Lee ◽  
Akira Ishihara ◽  
Ken Jacobson
Keyword(s):  
Silicone Rubber ◽  
Molecular Motors ◽  
Video Frame ◽  
Traction Forces ◽  
Cell Traction Forces ◽  
Latex Beads ◽  
Cell Traction ◽  
Local Cell ◽  
Microscopic Measurement ◽  
Kinetics Of

We are using video-enhanced light microscopy to investigate the pattern and magnitude of forces that fish keratocytes exert on flexible silicone rubber substrata. Our goal is a clearer understanding of the way molecular motors acting through the cytoskeleton co-ordinate their efforts into locomotion at cell velocities up to 1 μm/sec. Cell traction forces were previously observed as wrinkles(Fig.l) in strong silicone rubber films by Harris.(l) These forces are now measureable by two independant means.In the first of these assays, weakly crosslinked films are made, into which latex beads have been embedded.(Fig.2) These films report local cell-mediated traction forces as bead displacements in the plane of the film(Fig.3), which recover when the applied force is released. Calibrated flexible glass microneedles are then used to reproduce the translation of individual beads. We estimate the force required to distort these films to be 0.5 mdyne/μm of bead movement. Video-frame analysis of bead trajectories is providing data on the relative localisation, dissipation and kinetics of traction forces.

Author response for "Quantitative analysis of human NK cell reactivity using latex beads coated with defined amounts of antibodies"

2020 ◽  
Author(s):  
Madeleine Dorsch ◽  
Doris Urlaub ◽  
Vivian Bönnemann ◽  
Peter Bröde ◽  
Mina Sandusky ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Nk Cell ◽  
Author Response ◽  
Cell Reactivity ◽  
Latex Beads

Author response for "Quantitative analysis of human NK cell reactivity using latex beads coated with defined amounts of antibodies"

2019 ◽  
Author(s):  
Madeleine Dorsch ◽  
Doris Urlaub ◽  
Vivian Bönnemann ◽  
Peter Bröde ◽  
Mina Sandusky ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Nk Cell ◽  
Author Response ◽  
Cell Reactivity ◽  
Latex Beads

An Experimental Multiple-Organ Model for the Study of Regional Net Release/Uptake Rates of Tissue-type Plasminogen Activator in the Intact Pig

1997 ◽  
Vol 78 (03) ◽  
pp. 1150-1156 ◽  
Author(s):  
Christina Jern ◽  
Heléne Seeman-Lodding ◽  
Bjӧrn Biber ◽  
Ola Winsӧ ◽  
Sverker Jern
Keyword(s):  
Plasminogen Activator ◽  
Multiple Organ ◽  
Tissue Type ◽  
Hepatic Veins ◽  
Plasma Flows ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Uptake Rates ◽  
Net Release

SummaryExperimental data indicate large between-organs variations in rates of synthesis of tissue-type plasminogen activator (t-PA), which may reflect important differences in the capacity for constitutive and stimulated t-PA release from the vascular endothelium. In this report we describe a new multiple-organ experimental in vivo model for simultaneous determinations of net release/uptake rates of t-PA across the coronary, splanchnic, pulmonary, and hepatic vascular beds. In eleven intact anesthetized pigs, blood samples were obtained simultaneously from the proximal aorta, coronary sinus, pulmonary artery, and portal and hepatic veins. Plasma flows were monitored separately for each vascular region. Total plasma t-PA was determined by ELISA with a porcine t-PA standard. Regional net release/uptake rates were defined as the product of arteriovenous concentration gradients and local plasma flows. The net release of t-PA across the splanchnic vascular bed was very high, with a mean output of 1,919 ng total t-PA X min-1 (corresponding to 90 ng per min and 100 g tissue). The net coronary t-PA release was 68 ng X min-1 (30 ng X min-1 X 100 g"1)- Pulmonary net fluxes of t-PA were variable without any significant net t-PA release. The net hepatic uptake rate was 4,855 ng X min-1 (436 ng X min-1 X 100 g-1). Net trans-organ changes of active t-PA mirrored those of total t-PA. The results demonstrate marked regional differences in net release rates of t-PA in vivo. The experimental model we present offers new possibilities for evaluation of regional secretion patterns in the intact animal.

Improving vaccine uptake: a new uptake reporting tool

2018 ◽  
Vol 68 (suppl 1) ◽  
pp. bjgp18X697205
Author(s):  
Elise Tessier ◽  
Richard Pebody ◽  
Nicki Boddington ◽  
Michael Edelstein ◽  
Joanne White ◽  
...  
Keyword(s):  
Reporting System ◽  
Influenza Season ◽  
Vaccine Uptake ◽  
Web Based ◽  
Current Season ◽  
Previous Season ◽  
Uptake Rates ◽  
Reporting Tool ◽  
Uptake Data ◽  
Near Future

BackgroundVaccine uptake data is automatically extracted from all GP practices in England via the web-based reporting system, ImmForm, on behalf of Public Health England. In 2016/17, an Uptake Summary Tool was introduced on ImmForm for practice managers, clinical commissioning groups (CCGs) and screening and immunisation teams (SCRIMMS) to help facilitate local and regional management of the influenza programme. The tool allows practices to view and evaluate influenza uptake rates by target cohorts, comparing them against the previous season and CCG average/overall national uptake each week.AimTo assess how many practices use the Uptake Summary Tool and whether there is a difference in vaccine uptake among practices that use the tool compared with those that don’t during the 2016/17 and 2017/18 influenza seasons.MethodPractice level use of the Uptake Summary Tool was examined for the 2016/17 influenza season and vaccine uptake compared between practices that used the tool and those that did not.ResultsAn average of 1272 practices used the tool each week during the 2016/17. Vaccine uptake was on average 2.9% greater for targeted cohorts in practices that used the tool than practices that did not during the 2016/17 season.ConclusionWhen used on a regular basis the Uptake Summary Tool can help GP practices, CCGs and SCRIMMS monitor vaccine and may be associated with increased vaccine uptake. Uptake for the 2017/18 season will be monitored and assessed throughout the current season. We aim to expand the tool to other vaccine collections in the near future.

A study on the fouling phenomena of a microfiltration membrane

2004 ◽  
Vol 4 (5-6) ◽  
pp. 223-231
Author(s):  
H.-H. Yeh ◽  
W.-H. Wang
Keyword(s):  
Salicylic Acid ◽  
Humic Acid ◽  
Calcium Ion ◽  
Colloidal Particles ◽  
Alginic Acid ◽  
Particle System ◽  
Feed Water ◽  
Permeate Flux ◽  
Widespread Application ◽  
Latex Beads

The utilization of membrane processes for drinking water treatment has become more popular. However, fouling by source water probably is the major factor prohibits its widespread application. In this research, the fouling phenomena of a microfiltration (MF) membrane were studied. The interactions among colloidal particles, calcium ion, and dissolved organics, such as salicylic acid, humic acid, and alginic acid, on MF fouling were focused. A lab-scale single hollow fiber MF membrane, made of polyvinylidenefluoride (PVDF), module was used. The results show that, for single organic compound, the extent of fouling caused by humic acid was higher that of alginic acid. For the latter, the permeate flux decrease at lower pH was more significant than those at higher pH. For low MW salicylic acid, both rejection and flux decrease were minor. It seems that solubility have strong correlation with fouling rate. The higher the solubility is, the lower the fouling rate. For sole colloidal particle system, latex beads with diameter close to the pore size of MF membrane showed severe fouling. Adding Ca can aggregate the latex beads, and alleviate fouling. However, calcium ion also found to increase fouling of alginic acid on membrane under neutral or alkali pH condition, probably via charge neutralization and/or bridging. In conclusion, MF fouling seems to be strongly related to the type of organics, size of colloidal particles, and the existence of divalent ions, in the feed water.

Sign in / Sign up

Export Citation Format

Share Document