Silent period induced by cutaneous stimulation Uncini, A; Kujirai, T; Gluck, B ...
Electroencephalography and clinical neurophysiology,
10/1991, Letnik:
81, Številka:
5
Journal Article
An electrical stimulus applied to a cutaneous nerve during isometric muscle contraction causes a suppression of EMG activity (silent period) followed by a rebound. The extent of inhibition is related ...to the stimulus intensity as the silent period is more evident when stimulation is perceived as painful. The silent period is present in different limb and cranial muscles after stimulation of the same cutaneous nerve and in the same muscle after stimulation of distant cutaneous nerves. It also occurs synchronously in antagonist muscles. Within the silent period induced after cutaneous stimulation the maximal inhibition on the opponens pollicis motor neuron pool, as tested by the motor response evoked after transcranial cortical stimulation, occurs between 50 and 70 msec. Using the double stimulus technique to study the recovery cycle, the silent period is present at interstimulus intervals as low as 100 msec, and does not habituate with trains of stimuli at frequencies up to 5 Hz. Our results suggest that motor neuron inhibition from nociceptive stimulation may be mediated by Renshaw cells directly activated by high threshold cutaneous afferents.
Gluck, who had written an article about women's oral history in 1977, and Armitage, who addressed the issue in 1983, exchange ideas on current issues in women's oral history through electronic ...dialogue. Their e-mail dialogue is similar to an oral exchange, and they had to resist the urge to edit it to make it flow better.
As more and more information is moved around the organization and the
world using the growing E‐mail and electronic messaging infrastructure,
what technologies are available to ensure that these ...messages are
protected, that the recipient is positive of the sender′s identity and
that messages are not damaged or altered in transit? The paper‐based
world of message exchange takes these capabilities for granted by using
envelopes and signatures. How are these and similar protection
mechanisms implemented in the world of electronic documents, E‐mail and
electronic messaging? Provides a survey of the technology used to
provide digital signatures, message authentication and message
protection. It explains how these technologies work and how they can be
used in an existing messaging infrastructure to allow the sending and
receiving of sensitive information.
Previously unreported, we note the complication of anterior shoulder subluxation that occurred secondary to patient positioning during chest CT examination. Positioning a patient's arms abducted and ...externally rotated over the head can precipitate anterior shoulder subluxation in patients with anterior shoulder instability.
Serious neonatal coxsackievirus infections transplacentally acquired in late pregnancy involve primarily the central nervous system, heart, liver and rarely the skin. A boy born with a disseminated ...papulovesicular, nodular, bullous and necrotic ulcerated rash at 39 weeks gestational age developed pneumonia, carditis and hepatitis during the first days after birth. Molecular biological and serological methods were used for virological diagnosis. Coxsackievirus B3 (CVB3) was found in throat swabs and/or feces of the neonate and his mother. In addition, there was serological evidence of intrauterine infection. Intrauterine transmission of CVB3 during late pregnancy may lead to varicella-like congenital skin lesions.
The electrofusion of human cancer U937 and K562 cells was studied under the influence of a selected group of polypeptides and proteins adsorbed at their membranes. For poly-L-lysine, we found that ...the higher the molecular mass (M
m
) the higher the relative fusion yield (F
r
), whereas poly-L-arginine and poly-L-ornithine showed toxicity. As recently measured for barley protoplast fusion, the same rule of dependence on the isoelectric point (pI) could be verified:
which means 0.5 < F
r
< 4 in 0.3 M mannitol solution (pH 6). If the pH of the 0.3 M mannitol solution is the same as the pI of the protein, its influence on the membrane nearly disappears. Bridging by Ca ions increases F
r
from 0.5 (bovine serum albumin) to F
r
∼ 1 by charge compensation. The value of F
r
is commensurate with the pore resealing time τ-determined by trypan blue staining-in such a way that for pI > 8, τ is longer and for pI < 6, τ is shorter than the control without protein content. Qualitatively, plant and animal membranes studied show equal behavior. According to our technique, the adsorption of biopolymers and other substances can be detected by this bioelectrochemical method, which is also a tool for analysis of electric stress mechanisms.
Several polynucleotides were tested for interferon induction in comparison with the standard Poly (IC) in human diploid fibroblasts and in human leukocyte suspensions. We received high IFN-titre ...following superinduction of the polynucleotides in human fibroblasts. These results show that under superinduction conditions partly 3 times more interferon is induced in comparison with the standard inductor Poly (IC). The tested concentration of 10 micrograms/ml polynucleotides did not result in any IFN yields or only in very low ones in human leukocytes, which were only within the range of detectability.
Small but statistically significant shifts (hysteresis) between the up (increasing tension direction) and down (decreasing tension) pCa/tension relation for several muscle types of the rabbit and rat ...were found. The largest shift is, at most, 0.093 p units or 60% of that reported for the barnacle muscle. The direction of shift for psoas is opposite to that for the soleus and tibialis.
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