On the stochastic interpretation of a pathological cell renewal system, I: Theoretical basis

1964 ◽  
Vol 26 (3) ◽  
pp. 265-274 ◽  
Author(s):  
Stephen M. Shea
Keyword(s):  
Theoretical Basis ◽  
Cell Renewal ◽  
Renewal System

The adaptation of a two-compartment cell renewal system to external demands

1978 ◽  
Vol 194 (1) ◽  
pp. 163-170 ◽  
Author(s):  
Yael Michaeli ◽  
Gershom Zajicek ◽  
Joseph Regev
Keyword(s):  
Cell Renewal ◽  
Renewal System ◽  
Compartment Cell

Cell Renewal in the Gill of the Freshwater Mussel, Margaritifera Margaritifera: An Autoradiographic Study using High Specific Activity Tritiated Thymidine

1974 ◽  
Vol 14 (3) ◽  
pp. 561-569
Author(s):  
S. P. TOMASOVIC_ ◽  
M. C. MIX
Keyword(s):  
Specific Activity ◽  
Tritiated Thymidine ◽  
High Specific Activity ◽  
Freshwater Mussel ◽  
Autoradiographic Study ◽  
Cell Renewal ◽  
Margaritifera Margaritifera ◽  
Gill Epithelium ◽  
Stem Type ◽  
Renewal System

High specific activity tritiated thymidine (50.3 Ci/mM and 56 Ci/mM) and autoradiographic techniques were used to study cell renewal in the gill epithelium of the freshwater mussel, Margaritifera margaritifera. The cell renewal system in the gill epithelium of M. inargaritifera appears to consist of a stem-type population in the gill furrow and gill furrow edges which supplies, through division, cells for a maturing, dividing transient transitional population along the proximal gill ridge sides which, in turn, supplies cells to a simple transient, differentiated, functional population on the distal gill ridge sides and tip. Loss of cells from the cell renewal system appears to be through cell death and/or extrusion from the gill ridge tip. No emigration or immigration of labelled nuclei out of, or into, the gill epithelium was observed. The minimum transit time from the dividing transient population to the functional population in the gill ridge tip may be no more than 24 h. We were unable to detect any radiobiological effects or the presence of cytoplasmic labelling due to the use of high specific activities. However, such possibilities cannot be eliminated from consideration in further studies.

Cell renewal in the gills of the fish Barbus conchonius

1980 ◽  
Vol 58 (4) ◽  
pp. 650-653 ◽  
Author(s):  
Marlene MacKinnon ◽  
Hildegard E. Enesco
Keyword(s):  
Cell Migration ◽  
Cell Division ◽  
Epithelial Cells ◽  
Gill Filament ◽  
Gill Arch ◽  
Tropical Fish ◽  
Time Interval ◽  
Cell Renewal ◽  
A Cell ◽  
Renewal System

This radioautographic study established that the epithelial cells of the teleost gill have the cell division and cell migration patterns characteristic of a cell renewal system. [3H]Thymidine was injected into the small tropical fish Barbus conchonius, where it became incorporated into the newly synthesized DNA of dividing cells. Three fish were sacrificed at each of the following postinjection time intervals: 1, 12, 24, and 36 h. At 1 h, labeled nuclei were found only at the base of the gill filament, near the gill arch. At each successive time interval, labeled nuclei were found further out along the length of the gill filament. At later stages, labeled nuclei were also seen at the tips of the lamellae which project perpendicularly from the filaments. The number of labeled nuclei at the point of origin steadily declined with time. These data demonstrate that gill epithelial cells originate at the base of the gill arch and migrate both outward along the filament and upward along the lamellae. This pattern of cell division and cell migration demonstrates that the gill epithelium is a cell renewal system.

Video-Enhanced Microscopy--Better Visibility of Plant Cell Structures

1982 ◽  
Vol 40 ◽  
pp. 182-185
Author(s):  
N.S. Allen ◽  
R.D. Allen
Keyword(s):  
Diffraction Pattern ◽  
Theoretical Basis ◽  
Numerical Aperture ◽  
Gain Control ◽  
Control Unit ◽  
Camera Control ◽  
Variable Gain ◽  
Contrast Method ◽  
Fine Detail ◽  
Cell Structures

Various methods of video-enhanced microscopy combine TV cameras with light microscopes creating images with improved resolution, contrast and visibility of fine detail, which can be recorded rapidly and relatively inexpensively. The AVEC (Allen Video-enhanced Contrast) method avoids polarizing rectifiers, since the microscope is operated at retardations of λ/9- λ/4, where no anomaly is seen in the Airy diffraction pattern. The iris diaphram is opened fully to match the numerical aperture of the condenser to that of the objective. Under these conditions, no image can be realized either by eye or photographically. Yet the image becomes visible using the Hamamatsu C-1000-01 binary camera, if the camera control unit is equipped with variable gain control and an offset knob (which sets a clamp voltage of a D.C. restoration circuit). The theoretical basis for these improvements has been described.

Severe Paradoxical Dysphonia in Two Young Women

1993 ◽  
Vol 2 (3) ◽  
pp. 52-55 ◽  
Author(s):  
Michael Collins ◽  
Robert McDonald ◽  
Robert Stanley ◽  
Timothy Donovan ◽  
C. Frank Bonebrake
Keyword(s):  
Young Women ◽  
Theoretical Basis ◽  
Therapeutic Regimen ◽  
Instrumental Data ◽  
Relationship Of ◽  
The Relationship

This report describes an unusual and persistent dysphonia in two young women who had taken a therapeutic regimen of isotretinoin for intractable acne. We report perceptual and instrumental data for their dysphonia, and pose a theoretical basis for the relationship of dysphonia to this drug. We also provide recommendations for reducing the risk of acquiring a dysphonia during the course of treatment with isotretinoin.

Translation Research for the Rehabilitation of Left Spatial Neglect and Associated Disorders of Attention in Stroke Patients

2008 ◽  
Vol 18 (2) ◽  
pp. 55-65 ◽  
Author(s):  
Nkiruka Arene ◽  
Argye E. Hillis
Keyword(s):  
Theoretical Basis ◽  
Attention Bias ◽  
Spatial Neglect ◽  
Clinical Use ◽  
Stroke Patients ◽  
Translation Research ◽  
Unilateral Neglect ◽  
Assessment And Treatment ◽  
Sound Theoretical Basis ◽  
Review Current

Abstract The syndrome of unilateral neglect, typified by a lateralized attention bias and neglect of contralateral space, is an important cause of morbidity and disability after a stroke. In this review, we discuss the challenges that face researchers attempting to elucidate the mechanisms and effectiveness of rehabilitation treatments. The neglect syndrome is a heterogeneous disorder, and it is not clear which of its symptoms cause ongoing disability. We review current methods of neglect assessment and propose logical approaches to selecting treatments, while acknowledging that further study is still needed before some of these approaches can be translated into routine clinical use. We conclude with systems-level suggestions for hypothesis development that would hopefully form a sound theoretical basis for future approaches to the assessment and treatment of neglect.

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