scholarly journals STUDIES ON THE EFFECT OF CERTAIN TOXIC SUBSTANCES IN BACTERIAL CULTURES ON THE MOVEMENT OF THE INTESTINES

1926 ◽  
Vol 43 (6) ◽  
pp. 785-795 ◽  
Author(s):  
E. E. Ecker ◽  
A. Rademaekers
Keyword(s):  
Intravenous Injection ◽  
Toxic Substances ◽  
Propulsive Efficiency ◽  
Spasmodic Contraction ◽  
Strong Stimulation ◽  
Small Intestines ◽  
Slight Rise ◽  
Longitudinal Muscles ◽  
Stimulation Of

Following intravenous injection, filtrates of young cultures of B. paratyphosus B often produce marked diarrhea in rabbits. A study was made of the effect of these toxic filtrates on the motility of the small intestines of the rabbit. The observations were made on a segment of the small intestines in situ, and in the living animal. It was found that an immediate slight rise of tone of the longitudinal muscles occurred following intravenous injection of sterile broth. The same rise was noted after the injection of the toxic filtrate; but with these it was followed later (10 minutes elapsing at least) by a very strong but gradual rise of the diastolic and systolic tone, i.e., by spasmodic contraction of the intestinal muscle, which persisted at times for as long as 2 hours. In order to record simultaneously the effect on the longitudinal and circular muscles, and the propulsive efficiency of the segment the Sollmann and Rademaekers modification of Baur's technique was employed. This arrangement showed that the stimulation of the longitudinal muscles is accompanied by a similarly strong stimulation of the circular muscles, by peristalsis, and therefore by a greatly increased propulsion of intestinal contents which was sufficient to overcome the inhibition that usually occurs after preparation of the animal. With this arrangement an instance of peristaltic spasm was also noted. Broth alone failed to produce the phenomenon. Isotonic magnesium chloride or sulfate added to the bath relaxed the muscles again. Animals under deep urethane anesthesia did not show the diarrhea occurring in the intact controls, but sometimes exhibited it after the effect of the anesthetic had disappeared. So far no effects have been observed on the isolated strip (Magnus method), and further studies are being made to localize the effect, to neutralize it with a specific antiserum, and to observe the effect of filtrates of other members of the bacterial group including the dysentery bacilli.

In situ biomechanics of the syrinx and sound generation in pigeons.

1997 ◽  
Vol 200 (16) ◽  
pp. 2165-2176 ◽  
Author(s):  
F Goller ◽  
O N Larsen
Keyword(s):  
Tissue Adhesive ◽  
Sound Generation ◽  
Sound Stimulation ◽  
Direct Observations ◽  
Vibratory Motion ◽  
Strong Stimulation ◽  
Weak Stimulation ◽  
Stimulation Of

The in situ biomechanics of the vocal organ, the syrinx, was studied in anesthetized pigeons using fiberoptic instruments. The role of syringeal muscles was determined by electrical stimulation, and phonation was induced by injecting gas into the subsyringeal air sacs. This study presents the first direct observations of the biomechanical processes that occur in an intact syrinx. Contraction of one of the syringeal muscles, the m. tracheolateralis (TL), withdraws the lateral tympaniform membranes (LTM) from the syringeal lumen, causing opening of the syringeal airways. Shortening of a second muscle, the sternotrachealis (ST), draws the syringeal cartilages closer to each other, causing the LTM to fold into the syringeal lumen. Maximal ST contraction does not lead to complete closure of the syrinx. As air-sac pressure is increased by the injection of gas, the LTM are drawn into the syringeal lumen and balloon in a rostral direction until they touch, thus forming a fold-like valve. Air-induced phonation is always associated with vibrations of the membrane folds, suggesting that pulsatile release of air into the trachea by vibratory motion of the LTM generates sound. During air-induced phonation, strong stimulation of the TL terminates sound generation by abducting the LTM, whereas weak stimulation changes the geometry of the membrane folds, which is accompanied by changes in the acoustic structure of the sound. Stimulation of the ST has little effect on air-induced sounds. The LTM appear to be the main sound generators, since disabling the medial tympaniform membranes (MTM) with tissue adhesive does not prevent phonation or change the frequency and amplitude structure of display coos in spontaneously vocalizing pigeons. Moreover, the activity of the syringeal muscles appears to have a mainly modulatory function, suggesting that the basic sound-generating mechanism is similar in both air-induced and natural phonation.

scholarly journals Strong stimulation of N<sub>2</sub> fixation in oligotrophic Mediterranean Sea: results from dust addition in large in situ mesocosms

2013 ◽  
Vol 10 (6) ◽  
pp. 10581-10613 ◽  
Author(s):  
C. Ridame ◽  
C. Guieu ◽  
S. L'Helguen
Keyword(s):  
Mediterranean Sea ◽  
N2 Fixation ◽  
Saharan Dust ◽  
Dust Deposition ◽  
Strong Stimulation ◽  
Stimulation Of

Abstract. The response of N2 fixation to contrasted (wet and dry) Saharan dust deposition was studied in the framework of the DUNE project "a DUst experiment in a low-Nutrient, low-chlorophyll Ecosystem" during which realistic simulations of dust deposition (10 g m

Intravenous injection of hypertonic NaCl solution stimulates pulmonary C-fibers in dogs

1991 ◽  
Vol 260 (5) ◽  
pp. H1522-H1530 ◽  
Author(s):  
T. E. Pisarri ◽  
A. Jonzon ◽  
H. M. Coleridge ◽  
J. C. Coleridge
Keyword(s):  
Intravenous Injection ◽  
Pulmonary Circulation ◽  
Bronchial Artery ◽  
Dependent Manner ◽  
Nacl Solution ◽  
Impulse Frequency ◽  
Minimum Effective Concentration ◽  
C Fibers ◽  
Hypertonic Solutions ◽  
Stimulation Of

Intravenous injection of hypertonic NaCl solution evokes reflex bradycardia and hypotension, effects thought to result from stimulation of afferent vagal endings in the lungs. To identify the afferents responsible for these effects, we recorded vagal impulses arising from endings in the lungs and lower airways of anesthetized dogs and examined the response to injection of hypertonic solutions into the pulmonary circulation. Injection of 4,800 mmol/l NaCl solution (1 ml/kg) stimulated 39 of 49 pulmonary C-fibers, their impulse frequency increasing 35-fold. Stimulation was concentration dependent, the minimum effective concentration being between 1,200 and 4,800 mmol/l. Rapidly adapting receptors were also stimulated in a concentration-dependent manner, 35 of 41 receptors being stimulated by 4,800 mmol/l NaCl solution, firing increasing fivefold. Bronchial C-fibers were not stimulated by injection into the pulmonary circulation but were by injection into the bronchial artery. Hypertonic urea solutions had qualitatively similar but smaller effects on pulmonary C-fibers and rapidly adapting receptors. The results suggest that the reflex effects of intravenous injection of hypertonic solutions result principally from stimulation of pulmonary C-fibers.

Stimulation of the chemosensory TRPA1 cation channel by volatile toxic substances promotes cell survival of small cell lung cancer cells

2013 ◽  
Vol 85 (3) ◽  
pp. 426-438 ◽  
Author(s):  
Eva A.M. Schaefer ◽  
Stefanie Stohr ◽  
Michael Meister ◽  
Achim Aigner ◽  
Thomas Gudermann ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Small Cell Lung Cancer ◽  
Cell Survival ◽  
Cancer Cells ◽  
Cell Lung Cancer ◽  
Small Cell ◽  
Cation Channel ◽  
Toxic Substances ◽  
Small Cell Lung ◽  
Stimulation Of

Relation between cholinergic and histaminergic components in reflex vasodilatation in the dog

1978 ◽  
Vol 234 (3) ◽  
pp. H305-H311 ◽  
Author(s):  
F. Rengo ◽  
B. Trimarco ◽  
M. Chiariello ◽  
L. Sacca ◽  
R. Violini ◽  
...  
Keyword(s):  
Histamine Release ◽  
Intravenous Injection ◽  
Cholinergic System ◽  
Perfusion Pressure ◽  
Gracilis Muscle ◽  
Systemic Hypertension ◽  
Receptor Blockade ◽  
Acetyl Choline ◽  
Baroreceptor Stimulation ◽  
Stimulation Of

Previous studies have shown that phentolamine is able to reverse the reflex vasodilatation produced by transitory baroreceptor stimulation by blocking sympathetic, histaminergic, and cholinergic components. A direct anticholinergic action of phentolamine has never been described; however, since it is known that this drug is capable of inhibiting histamine release during the reflex vasodilatation, it is possible that its ability to block the cholinergic component of the reflex is related to the latter property. Therefore, this study was undertaken in an attempt to identify possible relationships between cholinergic and histaminergic components of the reflex vasodilatation. Accordingly, in mongrel dogs the gracilis muscle was isolated and perfused and then loaded with 14C-labeled histamine. A transitory systemic hypertension was induced by intravenous injection of norepinephrine; this produced a reflex vasodilatation, shown by the fall in perfusion pressure, which was accompanied by an increase of histamine release from the muscle. Vagal block induced by atropine pretreatment reduced the fall in perfusion pressure induced by the systemic hypertension and produced a reduction of histamine release during the vasodilatation. In another group of animals a vasodilatation in the perfused muscle was induced by injection of acetylcholine. This response was accompanied by an increase in histamine release from the gracilis muscle. Alpha-receptor blockade, which has been shown to inhibit histamine release, reduced this acetyl-choline-induced vasodilatation. These results, while confirming the participation of the cholinergic system in the reflex vasodilatation elicited by transitory stimulation of the arterial baroreceptors, seem to demonstrate that this component is mediated almost exclusively by histamine release.

scholarly journals In situ Stimulation of CD40 and Toll-like Receptor 3 Transforms Ovarian Cancer–Infiltrating Dendritic Cells from Immunosuppressive to Immunostimulatory Cells

2009 ◽  
Vol 69 (18) ◽  
pp. 7329-7337 ◽  
Author(s):  
Uciane K. Scarlett ◽  
Juan R. Cubillos-Ruiz ◽  
Yolanda C. Nesbeth ◽  
Diana G. Martinez ◽  
Xavier Engle ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Dendritic Cells ◽  
Toll Like Receptor ◽  
Stimulation Of

Multifunctional 3D electrode platform for real-time in situ monitoring and stimulation of cardiac tissues

2018 ◽  
Vol 112 ◽  
pp. 149-155 ◽  
Author(s):  
Ning Zhang ◽  
Flurin Stauffer ◽  
Benjamin R. Simona ◽  
Feng Zhang ◽  
Zhao-Ming Zhang ◽  
...  
Keyword(s):  
Real Time ◽  
In Situ Monitoring ◽  
Cardiac Tissues ◽  
3D Electrode ◽  
Stimulation Of

Control of proliferin gene expression in serum-stimulated mouse cells

1987 ◽  
Vol 7 (6) ◽  
pp. 2080-2086
Author(s):  
D I Linzer ◽  
E L Wilder
Keyword(s):  
Protein Synthesis ◽  
S Phase ◽  
Mrna Levels ◽  
3T3 Cells ◽  
Serum Stimulation ◽  
Posttranscriptional Processing ◽  
A Cell ◽  
Mouse Cells ◽  
Stimulation Of

The serum-inducible expression of proliferin genes in BALB/c 3T3 cells was found to be dependent on both protein synthesis and an extended presence of serum in the medium. Even though no mature proliferin mRNA was detected in serum-starved cells, transcription of the proliferin genes occurred in these resting-cell cultures, indicating that posttranscriptional events may be important for regulating proliferin mRNA levels. These results suggest that protein synthesis after serum stimulation of quiescent mouse fibroblasts is required for posttranscriptional processing or stabilization of proliferin RNA. Proliferin RNA levels were found to be heterogeneous among serum-stimulated cells analyzed by in situ hybridization. This heterogeneity is probably due to asynchrony in the population and may point to a correlation between the time of proliferin expression and the time of entry of a cell into S phase.

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