Patency of the follicular epithelium in Rhodnius prolixus: a re-examination of the hormone response and technique refinement

1980 ◽  
Vol 58 (9) ◽  
pp. 1617-1625 ◽  
Author(s):  
Erwin Huebner ◽  
Hampik S. Injeyan
Keyword(s):  
Regression Analysis ◽  
Juvenile Hormone ◽  
Evans Blue ◽  
Rhodnius Prolixus ◽  
Follicular Epithelium ◽  
Hormone Response ◽  
Penetration Test ◽  
Improved Method ◽  
Dye Penetration

The size of the extracellular spaces revealed by Evans' blue penetration into the follicular epithelium of Rhodnius prolixus increases with the stage of vitellogenesis. This was found to be true of follicles incubated in control media, as well as those whose spaces had been stimulated to expand by incubation in juvenile hormone (JH) or the analogue ZR515. An improved method of estimating hormonal effects in vitro utilizes a regression analysis of patency index relative to follicle length; with control follicles the slope was 0.44, whereas hormone- and analogue-treated follicles yielded slopes of 0.86 and 1.09, respectively. Some pitfalls of the dye penetration test are outlined.

Two actions of juvenile hormone on the follicle cells of Rhodnius prolixus Stål

1975 ◽  
Vol 53 (8) ◽  
pp. 1187-1188 ◽  
Author(s):  
Randa Abu-Hakima ◽  
K. G. Davey
Keyword(s):  
Juvenile Hormone ◽  
Developmental Stages ◽  
Normal Animal ◽  
Rhodnius Prolixus ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Intercellular Spaces

The follicular epithelium of vitellogenic oocytes from allatectomized females of Rhodnius fails to develop large intercellular spaces when exposed to juvenile hormone (JH) in vitro. This suggests that in the normal animal, the follicle cells require JH at two developmental stages. Differentiation of the cells in the presence of JH represents one requirement, and only those cells which have undergone this initial priming are fully competent to exhibit the second response, the development of intercellular spaces.

The response of the follicle cells of Rhodnius prolixus to juvenile hormone and antigonadotropin in vitro

1974 ◽  
Vol 52 (11) ◽  
pp. 1407-1412 ◽  
Author(s):  
K. G. Davey ◽  
E. Huebner
Keyword(s):  
Juvenile Hormone ◽  
Basal Medium ◽  
Rhodnius Prolixus ◽  
Effective Concentration ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
A Value

In a medium consisting of 40% Eagle's basal medium in Schneider's Drosophila medium, large spaces appear between the cells of the follicular epithelium over vitellogenic oocytes of Rhodnius prolixus when juvenile hormone is present. Such spaces are less prominent when juvenile hormone is absent. A method is described by which the size and number of spaces can be assigned a value, on a scale of 0–5, called the index of patency. The index of patency increases with increasing concentration of juvenile hormone from 10−15 μl/ml to 10−4 μl/ml. At higher concentrations, the index of patency decreases. When a source of antigonadotropin is present in the medium, together with juvenile hormone at its maximally effective concentration, the patency index is decreased.

scholarly journals In Vitro Effects of External Pressure Changes on the Sealing Ability under Simulated Diving Conditions

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Marcus Stoetzer ◽  
Martin Ruecker ◽  
Andreas Koch ◽  
Dirk Ziebolz ◽  
Horst Kokemüller ◽  
...  
Keyword(s):  
External Pressure ◽  
Chamber Pressure ◽  
Experimental Chamber ◽  
Penetration Test ◽  
Pulp Chamber ◽  
Dye Penetration ◽  
Gutta Percha ◽  
In Vitro Effects ◽  
Pressure Changes

Aim. To measure and validate the permeability of pressure changes in correlation to different root filling techniques. Methods. Eighty extracted single-rooted teeth were randomly assigned to one of eight groups of ten teeth. Following standardized instrumentation and irrigation, root canal fillings were performed using either cold lateral condensation, a warm carrier-based gutta-percha obturation technique, a warm carrier-based Resilon, or warm gutta-percha compaction with the downpack/backfill technique. After insertion of a pressure sensor within the pulp chamber ten teeth of each group then underwent simulated dives with pressure measurement and the other ten a dye penetration test during simulated dives to 5.0 bar. Differences were analyzed statistically (P<0.05) using one-way analysis of variance (ANOVA). Results. When the warm carrier-based gutta-percha obturation technique and vertical gutta-percha obturation techniques were used, there was significant lower intrapulpal pressure to experimental chamber pressure (P>0.05). When cold lateral condensation or carrier-based Resilon as used, pressure was sometimes almost completely equalized. Conclusions. Warm gutta-percha obturation techniques provide a largely pressure-tight seal whereas the Resilon obturation technique and cold lateral condensation appear to be unsuitable to pressure changes.

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