A Report of Further Impedance Studies of the Acoustic Reflex

1967 ◽  
Vol 10 (3) ◽  
pp. 616-622 ◽  
Author(s):  
Alan S. Feldman
Keyword(s):  
Muscle Contraction ◽  
Middle Ear ◽  
Surgical Intervention ◽  
Acoustic Stimulation ◽  
Bell’S Palsy ◽  
The Other ◽  
Acoustic Reflex ◽  
Stapedius Muscle ◽  
Other Hand ◽  
Stimulation Of

The result of acoustic stimulation of the middle ear muscles was studied using subjects in whom one or the other muscle contraction was known to be ineffective. Otosclerosis presented a condition of an intact pair of muscles but a stapes unresponsive to the contraction of the stapedius muscle. Bell’s Palsy represented a condition of a paralyzed stapedius muscle but an otherwise normal middle ear system. Through surgical intervention the ears of otosclerotic patients were altered by sectioning of the stapedius muscle and insertion of a prosthesis, while in other patients an exploratory tympanotomy verified that the middle ear was without pathology and then one or the other of the middle ear muscles was sectioned. All except one of these instances would eliminate the response of the stapedius muscle only, while the other would only eliminate the tensor tympani response. In each instance of restriction of response of the stapedius muscle the acoustic reflex could not be elicited. On the other hand, when the remainder of the system was intact and only the tensor tympani sectioned, the acoustic reflex appeared normal. These observations would strongly support the contention that the tensor tympani is not responsive to acoustic stimulation.

EFFECT OF ACTINOMYCIN D ON TSH-INDUCED STIMULATION OF THYROIDAL PROTEIN SYNTHESIS IN THE RAT

1974 ◽  
Vol 77 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gustav Wägar
Keyword(s):  
Protein Synthesis ◽  
Actinomycin D ◽  
The Other ◽  
Leucine Incorporation ◽  
Short Term ◽  
Other Hand ◽  
Thyroid Glands ◽  
Translational Level ◽  
Stimulation Of

ABSTRACT Whether the short-term regulation of thyroidal protein synthesis by TSH occurs at the transcriptional or the translational level was tested by measuring the effect of actinomycin D (act D) on the TSH-induced stimulation of L-14C-leucine incorporation into the thyroidal proteins of rats. TSH was injected 6 h before the rats were killed. The thyroid glands were then removed and incubated in vitro in the presence of L-14C-leucine for 2 h. The pronounced stimulation of leucine incorporation in the TSH-treated animals was depressed as compared with controls but still significant even when the animals had been pre-treated with 100 μg act D 24 and 7 h before sacrifice. On the other hand, act D strongly decreased incorporation of 3H-uridine into RNA. Short-term regulation of thyroidal protein synthesis by TSH appears to be partly but not wholly dependent on neosynthesis of RNA. Hence regulation may partly occur at the translation level of protein synthesis.

On Research and Other Matters

1922 ◽  
Vol 26 (140) ◽  
pp. 325-330
Author(s):  
S. Heckstall Smith
Keyword(s):  
British Empire ◽  
Air Force ◽  
The Other ◽  
Other Hand ◽  
Secretary Of State ◽  
The Press ◽  
The Subject ◽  
Stimulation Of

If the thought of another war troubles you, then don't read this article. If you would rather say to yourself as the Secretary of State said to the Air Conference, “ There won't be another war for ten years, so why worry? ” then no doubt you will think with him that it is better to let other nations have alk the bother and expense of trying to advance; after all, we are jolly fine fellows and can soon pick up. If, on the other hand, you have imagination which gives you a nasty queasy sensation when you think of what might be, then perhaps the following notes, albeit disjointed and mostly stale, may at least conjure up in you thoughts of your own on the subject. This is all that is needed to help, our advancement in the air–the stimulation of spoken and written thoughts by the British nation, for if every taxpayer in the British Empire says “ Air Force,” then the Press and Parliament will say it too.

Control of breathing in craniotes

2019 ◽  
pp. 164-169
Author(s):  
Steven F. Perry ◽  
Markus Lambertz ◽  
Anke Schmitz
Keyword(s):  
Muscle Contraction ◽  
Muscle Activity ◽  
Control Of Breathing ◽  
The Other ◽  
Air Breathing ◽  
Ventilatory Frequency ◽  
Blood Ph ◽  
Other Hand

Craniote gills are arranged sequentially along the pharynx and accordingly are ventilated from anterior to posterior by a wave of muscle contraction, beginning with the mouth. Each gill pair appears to have its own set of neurons in the brainstem that coordinate the muscle activity and stimulate the next gill pair in the sequence. This system appears to have been maintained from hagfish to teleosts. In tetrapods, on the other hand, various centres in the brainstem coordinate different phases of breathing: expiration, inspiration, and post-inspiration. The location of these centres in the brainstem is similar in amphibians and mammals. The stimulus for regulating ventilatory frequency in water-breathing species is oxygen, whereas for air-breathing species it is blood pH/PCO2—just as in invertebrates.

Relationships between acoustic reflex patterns elicited by unfiltered white noise and narrow band white noise stimuli of different duration but of the same intensity

1985 ◽  
Vol 99 (9) ◽  
pp. 857-863 ◽  
Author(s):  
Giovanni Rossi ◽  
Paolo Solero ◽  
M. Rolando
Keyword(s):  
White Noise ◽  
Narrow Band ◽  
Acoustic Signals ◽  
The Other ◽  
Acoustic Reflex ◽  
Other Hand ◽  
Recruitment Time

AbstractFor the purpose of this study, acoustic signals were generated by an Amplaid MK VI. An Amplaid 702 impedence meter was connected to its averaging section and to its computer. The stimuli were bursts of unfiltered white noise (UWN) and of narrow band white noise (NBWN; 30 db./oct/slope; central frequencies 1,000, 2,000, 4,000 Hz.) lasting 3–1,000 msec, at intensity of 105 db. SPL p.e. The following parameters were evaluated: stapedius contraction latency, amplitude, duration and recruitment time. It was found that latency was independent of the spectrum of the stimulus and its duration. Amplitude and recruitment time, on the other hand, were related to spectrum and duration, while duration of contraction was directly related to the duration of the stimulus only.

Localization of Spontaneous Respiratory Neuronal Activities in the Medulla Oblongata of the Cat: A New Location of the Expiratory Center

1957 ◽  
Vol 190 (2) ◽  
pp. 350-355 ◽  
Author(s):  
Edgar Haber ◽  
Kurt W. Kohn ◽  
S. H. Ngai ◽  
D. A. Holaday ◽  
S. C. Wang
Keyword(s):  
Vagus Nerve ◽  
Reticular Formation ◽  
Medulla Oblongata ◽  
Electric Stimulation ◽  
The Other ◽  
Drug Induced ◽  
Other Hand ◽  
Twin Beam ◽  
New Location ◽  
Stimulation Of

Medulla oblongata of 80 vagotomized cats was explored with microelectrodes. Spontaneous respiratory neuronal activities and chest movements were recorded simultaneously with a twin beam cathode ray oscilloscope. It was found that inspiratory discharges are concentrated in the reticular formation between 3 mm rostral and 1 mm caudal to the level of the obex, which corresponds approximately to the inspiratory region of Pitts, Magoun and Ranson. On the other hand, expiratory discharges are not obtained in Pitts' expiratory area, but are found in a circumscribed region in the reticular formation from the level of the obex to 3 mm caudally. Electric stimulation of this region has been found recently by Ngai and Wang to yield marked expiratory spasm. It is concluded that the expiratory center is located caudally to the inspiratory center in the cat. The spontaneous respiratory neuronal discharges continue with no alterations of pattern of firing during drug-induced respiratory paralysis, and are increased both in number and in frequency during CO2 inhalation. Stimulation of the vagus nerve with 50 shocks/sec. reduces inspiratory discharges and prolongs the duration of expiratory discharges.

Saccadic eye movements evoked by microstimulation of the fastigial nucleus of macaque monkeys

1988 ◽  
Vol 60 (3) ◽  
pp. 1036-1052 ◽  
Author(s):  
H. Noda ◽  
S. Murakami ◽  
J. Yamada ◽  
J. Tamada ◽  
Y. Tamaki ◽  
...  
Keyword(s):  
Eye Movements ◽  
White Matter ◽  
Purkinje Cells ◽  
Saccadic Eye Movements ◽  
The Other ◽  
Fastigial Nucleus ◽  
Threshold Region ◽  
Other Hand ◽  
Low Threshold ◽  
Stimulation Of

1. Systematic exploration throughout the deep cerebellar nuclei and white matter disclosed that the region from which saccadic eye movements (saccades) were evoked with weak currents (less than 10 microA) was confined to the fastigial nucleus and the adjacent white matter. 2. When an electrode for stimulation was advanced in the cerebellum, saccades were evoked in the direction of the stimulated side (ipsilateral saccades) as it entered the low-threshold region. In some tracks, particularly when the electrode was advanced in the medial portion of the fastigial nucleus, the direction of the evoked saccades changed from the ipsilateral to the contralateral. 3. The mappings with microstimulation disclosed that the ipsilateral saccades were elicited from a relatively wide region that included almost the full extent of the fastigial nucleus. The low-threshold region continued in the white matter caudally into vermal lobule VII and rostrally into the dorsal aspect of the brachium conjunctivum. On the other hand, the contralateral saccades were evoked from a relatively circumscribed region in the ventromedial portion of the fastigial nucleus. 4. The reversal in the direction of the horizontal component occurred always in a narrow zone in the core of the fastigial nucleus. The caudal part of this zone coincided with an ellipsoidal region where anterogradely labeled axons of the Purkinje cells terminated when HRP was injected into vermal lobule VII. 5. When bicuculline (0.2-1 microgram) was injected in the ellipsoidal region, the ipsilateral saccades evoked from the dorsocaudal aspect of the region were suppressed for several hours. On the other hand, the contralateral saccades evoked from the ventromedial portion of the fastigial nucleus were either unchanged or enhanced. 6. Because the ipsilateral saccades were suppressed by bicuculline, they were most probably evoked by stimulation of the presynaptic component of gamma-amino-butyric acid-(GABA) mediated synapses, namely the axons of Purkinje cells. 7. Because stimulation of the presynaptic component of the inhibitory synapses evoked ipsilateral saccades, activation of the postsynaptic component would evoke contralateral saccades. In fact, the distribution of the fastigial sites yielding contralateral saccades coincided with the course of axons of fastigial neurons arising in the ellipsoidal region. It is most likely, therefore, that the contralateral saccades were evoked by stimulation of fastigial neurons.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals THE NERVOUS MECHANISM OF COORDINATION IN THE CRINOID, ANTEDON ROSACEUS

1924 ◽  
Vol 6 (3) ◽  
pp. 281-288 ◽  
Author(s):  
A. R. Moore
Keyword(s):  
Ventral Side ◽  
Ventral Surface ◽  
Reciprocal Inhibition ◽  
The Other ◽  
Dynamic Symmetry ◽  
Other Hand ◽  
Stimulation Of

1. Stimulation causes Antedon to swim by means of alternate oral bending and dorsal stroke of the arms. Two arms of a given ray move alternately so that while one is executing the aboral stroke its mate is flexing ventrally. This implies reciprocal inhibition. 2. Recriprocal inhibition between the two arms of an isolated ray can be abolished by the use of either strychnine or nicotine. 3. Coordination between the rays is referable to the conducting properties of the nervous pentagon which connects the five rays. In this system an impulse loses in effectiveness as it passes from the point of origin. 4. When Antedon is made to rest oral face down on the floor of an aquarium, oral flexion of all the rays, swimming movements, and righting result. Antedon is therefore negatively stereotropic with reference to its ventral side. 5. Excitation of the dorsal cirri results in aboral bending of all the rays. Stimulation of the cirri inhibits ventral flexion to the extent of preventing righting movements while on the other hand stimulation of the ventral surface inhibits the grasp reflex of the cirri. Thus oral and aboral sides of Antedon exhibit dynamic symmetry although structurally dissimilar.

scholarly journals Pneumoperitoneum, Pneumothorax, and Pneumoretroperitoneum Post Colonoscopy: A Case report and Review of Literature

2020 ◽  
pp. 102-105
Author(s):  
Melissa Kyriakos Saad ◽  
Toufic Saber ◽  
George Cortas ◽  
Elias Saikaly
Keyword(s):  
Case Report ◽  
Conservative Management ◽  
Watchful Waiting ◽  
Surgical Intervention ◽  
Colonic Perforation ◽  
The Other ◽  
Review Of Literature ◽  
The Real ◽  
Other Hand ◽  
Real Challenge

Colonic perforation post colonoscopy is rarely seen; however, when coupled with massive pneumoperitoneum in haemodynamically stable patients, a real dilemma for surgeons is created. The decision between watchful waiting versus surgical intervention is the real challenge and while most surgeons will urge for surgical intervention, conservative management on the other hand can be safely applied in selected haemodynamically stable patients.

Tympanometry

1981 ◽  
Vol 2 (9) ◽  
pp. 266-294
Keyword(s):  
Middle Ear ◽  
External Auditory Canal ◽  
The Other ◽  
Middle Ear Effusion ◽  
Other Hand ◽  
Free Environment ◽  
Sound Conduction ◽  
Otoscopic Examination ◽  
Ear Effusion

Tympanometry as a test of otologic status has the following attributes, uses, and advantages: (1) can be carried out simply, rapidly, and atraumatically, by appropriately trained nonprofessionals; (2) does not require, as does conventional audiometry, a sound-free environment; (3) is not influenced by the amount of cerumen ordinarily present in the external auditory canal; (4) is entirely objective, requiring no response on the part of the patient; (5) is exceedingly sensitive in detecting middle-ear effusion (or other middle-ear abnormalities that affect sound conduction); (6) is therefore useful in office screening, especially of difficult-to-examine patients, by (a) virtually obviating the need for routine otoscopic examination in patients more than 6 months of age who are asymptomatic and have normal tracings, and on the other hand (b) pointing up the need for further diagnostic attention to patients whose tracings are abnormal;

CORTICOID PRODUCTION IN VITRO AS A TEST OF ADRENOCORTICAL FUNCTION IN RATS

1960 ◽  
Vol XXXIII (I) ◽  
pp. 59-66 ◽  
Author(s):  
J. van der Vies
Keyword(s):  
Adrenal Cortex ◽  
Adrenal Function ◽  
The Other ◽  
Adrenocortical Function ◽  
Experimental Conditions ◽  
Adrenal System ◽  
Other Hand ◽  
Stimulation Of

ABSTRACT Adrenal function in rats under various experimental conditions was studied by incubating the adrenals in vitro and determining the corticosteroid output during one hour. This in vitro corticoid production was reduced after hypophysectomy, hypothalamus-lesioning and treatment with hydrocortisone or with Nembutal and morphine. On the other hand, an increased production was observed following stimulation of the pituitary-adrenal system by exogenous histamine or corticotrophin. From these experiments it is concluded that the corticoid production in vitro reflects the activity of the adrenal cortex in vivo and hence can be used for the study of the latter function.

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