scholarly journals An Accurate Method to Determine Bowman's Layer Thickness In Vivo in the Human Cornea

2012 ◽  
Vol 53 (4) ◽  
pp. 2354 ◽  
Author(s):  
Johan Germundsson ◽  
Per Fagerholm ◽  
Marina Koulikovska ◽  
Neil S. Lagali
Keyword(s):  
Layer Thickness ◽  
Accurate Method ◽  
Human Cornea

scholarly journals Optical System Design for Noncontact, Normal Incidence, THz Imaging of in vivo Human Cornea

2018 ◽  
Vol 8 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Shijun Sung ◽  
Alex Li ◽  
Sophie X. Deng ◽  
Elliott Brown ◽  
Warren S. Grundfest ◽  
...  
Keyword(s):  
System Design ◽  
Optical System ◽  
Normal Incidence ◽  
Human Cornea ◽  
Thz Imaging ◽  
Optical System Design

Measurements of the jejunal unstirred layer in normal subjects and patients with celiac disease

1996 ◽  
Vol 270 (3) ◽  
pp. G487-G491 ◽  
Author(s):  
A. Strocchi ◽  
G. Corazza ◽  
J. Furne ◽  
C. Fine ◽  
A. Di Sario ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Layer Thickness ◽  
Villous Atrophy ◽  
Normal Subjects ◽  
Unstirred Layer ◽  
Maximal Velocity ◽  
Normal Rat ◽  
Kinetics Of

Normal intestinal absorption of nutrients requires efficient luminal mixing to deliver solute to the brush border. Lacking such mixing, the buildup of thick unstirred layers over the mucosa markedly retards absorption of rapidly transported compounds. Using a technique based on the kinetics of maltose hydrolysis, we measured the unstirred layer thickness of the jejunum of normal subjects and patients with celiac disease, as well as that of the normal rat. The jejunum of humans and rats was perfused with varying maltose concentrations, and the apparent Michaelis constant (Km) and maximal velocity (Vmax) of maltose hydrolysis were determined from double-reciprocal plots. The true Km of intestinal maltase was determined on mucosal biopsies. Unstirred layer thickness was calculated from the in vivo Vmax and apparent Km and the in vitro Km of maltase. The average unstirred layer thickness of 11 celiac patients (170 micron) was seven times greater than that of 3 controls (25 micron). The unstirred layer of each celiac exceeded that of the controls. A variety of factors could account for the less efficient luminal stirring observed in celiacs. Although speculative, villous contractility could be an important stirring mechanism that would be absent in celiacs with villous atrophy. This speculation was supported by the finding of a relatively thick unstirred layer (mean: 106 micron) in rats, an animal that lacks villous contractility. Because any increase in unstirred layer slows transport of rapidly absorbed compounds, poor stirring appears to represent a previously unrecognized defect that could contribute to malabsorption in celiac disease and, perhaps, in other intestinal disorders.

scholarly journals In vivo measurement of intrauterine pressure by telemetry: a new approach for studying parturition in mouse models

2010 ◽  
Vol 42 (2) ◽  
pp. 310-316 ◽  
Author(s):  
Stephanie L. Pierce ◽  
William Kutschke ◽  
Rafael Cabeza ◽  
Sarah K. England
Keyword(s):  
Mouse Models ◽  
Accurate Method ◽  
Isometric Tension ◽  
Mouse Uterus ◽  
New Approach ◽  
In Vivo Measurement ◽  
Intrauterine Pressure

Transgenic and knockout mouse models have proven useful in the study of genes necessary for parturition—including genes that affect the timing and/or progression of labor contractions. However, taking full advantage of these models will require a detailed characterization of the contractile patterns in the mouse uterus. Currently the best methodology for this has been measurement of isometric tension in isolated muscle strips in vitro. However, this methodology does not provide a real-time measure of changes in uterine pressure over the course of pregnancy. Recent advances have opened the possibility of using radiotelemetric devices to more accurately and comprehensively study intrauterine pressure in vivo. We tested the effectiveness of this technology in the mouse, in both wild-type (WT) mice and a mouse model of defective parturition (SK3 channel-overexpressing mice), after surgical implant of telemetry transmitters into the uterine horn. Continuous recordings from day 18 of pregnancy through delivery revealed that WT mice typically deliver during the 12-h dark cycle after 19.5 days postcoitum. In these mice, intrauterine pressure gradually increases during this cycle, to threefold greater than that measured during the 12-h cycle before delivery. SK3-overexpressing mice, by contrast, exhibited lower intrauterine pressure over the same period. These results are consistent with the outcome of previous in vitro studies, and they indicate that telemetry is an accurate method for measuring uterine contraction, and hence parturition, in mice. The use of this technology will lead to important novel insights into changes in intrauterine pressure during the course of pregnancy.

scholarly journals A new methodology for the in vivo estimation of the elastic constants that characterize the patient-specific biomechanical behavior of the human cornea

2015 ◽  
Vol 48 (1) ◽  
pp. 38-43 ◽  
Author(s):  
M.A. Lago ◽  
M.J. Rupérez ◽  
F. Martínez-Martínez ◽  
C. Monserrat ◽  
E. Larra ◽  
...  
Keyword(s):  
Elastic Constants ◽  
Patient Specific ◽  
Human Cornea ◽  
Biomechanical Behavior

Extraction and determination of chloroform in rat blood and tissues by gas chromatography-electron-capture detection: distribution of chloroform in the animal body.

1980 ◽  
Vol 26 (1) ◽  
pp. 66-68 ◽  
Author(s):  
C R Vogt ◽  
J C Liao ◽  
A Y Sun
Keyword(s):  
Gas Chromatography ◽  
Detection Limit ◽  
Accurate Method ◽  
Electron Capture Detection ◽  
Fat Tissue ◽  
Rat Blood ◽  
Kidney Liver ◽  
Different Tissues

Abstract We have developed a simple, sensitive, and accurate method for the determination of chloroform in rat blood, brain, kidney, liver, and fat. The detection limit is 2.5 ng of chloroform per gram of tissue. Studies of in vivo distribution of chloroform in rat blood and target tissues after intragastric intubation of chloroform/water show that the amount of chloroform accumulated in the different tissues increases with increasing doses. Fat tissue contains the greatest amount of chloroform. The accumulation of chloroform in rat blood and target tissues seems to be maximum 1.5 h after administration, and the apparent chloroform concentration is almost at baseline value 8 h later.

Ultraviolet Photography of the In Vivo Human Cornea Unmasks the Hudson-Stähli Line and Physiologic Vortex Patterns

2005 ◽  
Vol 46 (10) ◽  
pp. 3616 ◽  
Author(s):  
Sean G. Every ◽  
John P. Leader ◽  
Anthony C. B. Molteno ◽  
Tui H. Bevin ◽  
Gordon Sanderson
Keyword(s):  
Human Cornea ◽  
Vortex Patterns ◽  
Ultraviolet Photography

In-vivo volumetric imaging of the cellular structure of healthy and pathological human cornea with high-speed UHR-OCT (Conference Presentation)

2018 ◽  
Author(s):  
Zohreh Hosseinaee ◽  
Bingyao Tan ◽  
Kirsten Carter ◽  
Denise Hileeto ◽  
Luigina Sorbara ◽  
...  
Keyword(s):  
Cellular Structure ◽  
High Speed ◽  
Human Cornea ◽  
Volumetric Imaging

scholarly journals Use of laser fluorescence (DIAGNOdentTM) for in vivo diagnosis of occlusal caries: a systematic review

2004 ◽  
Vol 12 (3) ◽  
pp. 177-181 ◽  
Author(s):  
Isauremi Vieira de Assunção Pinheiro ◽  
Maria Cristina dos Santos Medeiros ◽  
Maria Ângela Fernandes Ferreira ◽  
Kenio Costa de Lima
Keyword(s):  
Systematic Review ◽  
Gold Standard ◽  
Visual Inspection ◽  
Accurate Method ◽  
Laser Fluorescence ◽  
Permanent Teeth ◽  
Cochrane Library ◽  
Occlusal Caries ◽  
In Vivo Diagnosis

This systematic review was conducted to assess the accuracy of laser fluorescence (DIAGNOdentTM) for diagnosis of occlusal caries in permanent teeth, using any sort of gold standard. The MEDLINE, LILACS, BBO and Cochrane library databases accessed by BIREME were searched for English, Spanish and Portuguese-language papers published between 1982 and 2003. Four works in English were selected. DIAGNOdentTM was found to be an accurate method for diagnosis of occlusal caries, mainly if employed simultaneously with visual inspection.

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