scholarly journals Physiological control mechanism of gastrointestinal motility.

1990 ◽  
Vol 26 (2) ◽  
pp. 93-106 ◽  
Author(s):  
Kazumoto FUJII
Keyword(s):  
Gastrointestinal Motility ◽  
Control Mechanism ◽  
Physiological Control

Physiological correlations of population density in the eastern chipmunk (Tamias striatus) and the white-footed mouse (Peromyscus leucopus)

1969 ◽  
Vol 47 (3) ◽  
pp. 427-433 ◽  
Author(s):  
F. V. Clulow ◽  
A. DesMarais ◽  
J. Vaillancourt
Keyword(s):  
Population Density ◽  
Adrenal Cortex ◽  
Control Mechanism ◽  
Peromyscus Leucopus ◽  
Physiological Control ◽  
Tamias Striatus ◽  
Adrenocortical Activity ◽  
Eastern Chipmunk ◽  
Eastern Chipmunks ◽  
White Footed Mouse

Populations of various densities of eastern, chipmunks (Tamias striatus lysteri (Richardson) and white-footed mice (Peromyscus leucopus noveboracensis (Fischer) were formed by the introduction of wild-trapped animals onto islands of different size on Heney (Little Whitefish) Lake, Quebec.The animals were subsequently recaptured and various indicators of adrenocortical activity, including levels of circulating eosinophils and plasma corticostcroids, were measured. The evidence indicated that activation of the adrenal cortex is directly correlated with population density in T. striatus but not in P. leucopus.The conclusions are discussed in relation to current theories on the regulation of mammalian population including J. J. Christian's hypothetical behavioural–physiological control mechanism.

scholarly journals Glow on Sharks: State of the Art on Bioluminescence Research

Oceans ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 822-842
Author(s):  
Laurent Duchatelet ◽  
Julien M. Claes ◽  
Jérôme Delroisse ◽  
Patrick Flammang ◽  
Jérôme Mallefet
Keyword(s):  
Deep Sea ◽  
Control Mechanism ◽  
State Of The Art ◽  
Future Research ◽  
Histological Structure ◽  
Special Focus ◽  
Physiological Control ◽  
Ecological Functions ◽  
Similarities And Differences ◽  
Dim Light

This review presents a synthesis of shark bioluminescence knowledge. Up to date, bioluminescent sharks are found only in Squaliformes, and specifically in Etmopteridae, Dalatiidae and Somniosidae families. The state-of-the-art knowledge about the evolution, ecological functions, histological structure, the associated squamation and physiological control of the photogenic organs of these elusive deep-sea sharks is presented. Special focus is given to their unique and singular hormonal luminescence control mechanism. In this context, the implication of the photophore-associated extraocular photoreception—which complements the visual adaptations of bioluminescent sharks to perceive residual downwelling light and luminescence in dim light environment—in the hormonally based luminescence control is depicted in detail. Similarities and differences between shark families are highlighted and support the hypothesis of an evolutionary unique ancestral appearance of luminescence in elasmobranchs. Finally, potential areas for future research on shark luminescence are presented.

DOUBLE ISOTOPE DILUTION DERIVATIVE TECHNIQUE FOR TESTOSTERONE GLUCURONOSIDE IN URINE

1968 ◽  
Vol 58 (1) ◽  
pp. 77-97 ◽  
Author(s):  
Maria I. New ◽  
Joel M. Gross ◽  
Ralph E. Peterson
Keyword(s):  
Isotope Dilution ◽  
Adrenal Glands ◽  
Control Mechanism ◽  
Biological Fluids ◽  
Adrenal Hyperplasia ◽  
Physiological Control ◽  
Idiopathic Hirsutism ◽  
Normal Males ◽  
Double Isotope

ABSTRACT A double isotope dilution derivative technique for the determination of testosterone glucuronoside in urine has been developed. This is a highly specific and sensitive method which is applicable to the measurement of testosterone in submicrogram amounts in urine and other biological fluids. This method has been used to study normal prepubertal and pubertal males, normal females and subjects with gonadal dysgenesis, Cushing's syndrome, congenital adrenal hyperplasia, idiopathic hirsutism, Addison's disease and hypogonadism. The patients were studied after stimulation and suppression of gonads or adrenal glands to delineate the source of the androgen and its physiological control mechanism. The testosterone production of normal males determined by the method presented herein corresponds to results of others.

scholarly journals Helicobacter pylori: a Eubacterium Lacking the Stringent Response

1999 ◽  
Vol 181 (2) ◽  
pp. 552-555 ◽  
Author(s):  
Gian Luca Scoarughi ◽  
Carmen Cimmino ◽  
Pierluigi Donini
Keyword(s):  
Helicobacter Pylori ◽  
Amino Acid ◽  
16S Rrna ◽  
Control Mechanism ◽  
Stringent Response ◽  
Amino Acid Starvation ◽  
Wild Type ◽  
Physiological Control ◽  
Enzymatic Machinery ◽  
Type Strains

ABSTRACT Accumulation of 16S rRNA and production of guanosine polyphosphates (pppGpp and ppGpp) were studied during amino acid starvation in three wild-type strains of Helicobacter pylori. All strains exhibit a relaxed phenotype with respect to accumulation of 16S rRNA. This constitutes the first example of a wild-type eubacterium showing a relaxed phenotype. The guanosine polyphosphate levels do not rise as a result of amino acid starvation, as expected for relaxed organisms. However, in both growing and starved cells, basal levels of the two polyphosphates appeared to be present, demonstrating that the enzymatic machinery for guanosine polyphosphate production is present in this organism. These findings are discussed within the framework of the hypothesis that stringent control is a physiological control mechanism more important for the fitness of prokaryotes growing in the general environment than for those that inhabit protected niches.

Role of the Cilia Membrane in Control of Microtubule Sliding

1980 ◽  
Vol 38 ◽  
pp. 612-615
Author(s):  
Edna S. Kaneshiro
Keyword(s):  
Control Mechanism ◽  
Beat Frequency ◽  
Surface Membrane ◽  
Ciliary Membrane ◽  
Ciliary Beating ◽  
Ciliary Reversal ◽  
Voltage Dependent ◽  
Reversal Mechanism ◽  
And Function

It is currently believed that ciliary beating results from microtubule sliding which is restricted in regions to cause bending. Cilia beat can be modified to bring about changes in beat frequency, cessation of beat and reversal in beat direction. In ciliated protozoans these modifications which determine swimming behavior have been shown to be related to intracellular (intraciliary) Ca2+ concentrations. The Ca2+ levels are in turn governed by the surface ciliary membrane which exhibits increased Ca2+ conductance (permeability) in response to depolarization. Mutants with altered behaviors have been isolated. Pawn mutants fail to exhibit reversal of the effective stroke of ciliary beat and therefore cannot swim backward. They lack the increased inward Ca2+ current in response to depolarizing stimuli. Both normal and pawn Paramecium made leaky to Ca2+ by Triton extrac¬tion of the surface membrane exhibit backward swimming only in reactivating solutions containing greater than IO-6 M Ca2+ Thus in pawns the ciliary reversal mechanism itself is left operational and only the control mechanism at the membrane is affected. The topographic location of voltage-dependent Ca2+ channels has been identified as a component of the ciliary mem¬brane since the inward Ca2+ conductance response is eliminated by deciliation and the return of the response occurs during cilia regeneration. Since the ciliary membrane has been impli¬cated in the control of Ca2+ levels in the cilium and therefore is the site of at least one kind of control of microtubule sliding, we have focused our attention on understanding the structure and function of the membrane.

Gastrointestinal Motility as Revealed by Study of Abdominal Sounds

1955 ◽  
Vol 29 (5) ◽  
pp. 789-802 ◽  
Author(s):  
John T. Farrar ◽  
Franz J. Ingelfinger
Keyword(s):  
Gastrointestinal Motility

Oral Banthine, an Effective Depressor of Gastrointestinal Motility

1951 ◽  
Vol 17 (4) ◽  
pp. 551-559 ◽  
Author(s):  
Michael J. Lepore ◽  
Ross Golden ◽  
Charles A. Flood
Keyword(s):  
Gastrointestinal Motility

Tu1761 DEVELOPMENT OF A MOTILITY FRAILTY INDEX IN PATIENTS WITH GASTROINTESTINAL MOTILITY SYMPTOMS

2020 ◽  
Vol 158 (6) ◽  
pp. S-1149-S-1150
Author(s):  
Jared T. Winston ◽  
Patricia Guzman Rojas ◽  
Abigail Stocker ◽  
Douglas Lorenz ◽  
Michael W. Daniels ◽  
...  
Keyword(s):  
Gastrointestinal Motility ◽  
Frailty Index

Comparative Effects of Pamine, Banthine, and Placebos on Gastrointestinal Motility

1955 ◽  
Vol 28 (4) ◽  
pp. 500-509 ◽  
Author(s):  
William P. Chapman ◽  
Stanley M. Wyman ◽  
Jacques O. Gagnon ◽  
John A. Benson ◽  
Chester M. Jones ◽  
...  
Keyword(s):  
Gastrointestinal Motility
Sign in / Sign up

Export Citation Format

Share Document