Biomedical subjects

G Raymond

Publications and source records attributed to G Raymond.

At least 127 records · Page 7Linked to original sources

PubMed1981

[Effects of local anesthetics (procaine, tetracaine) on slow calcium permeability and contraction of frog skeletal muscle fiber].

Slow inward calcium current and contraction were simultaneously recorded from isolated muscle fibres. When the release of calcium form the SR was blocked by local anaesthetics (Procaine, Tetracaine), the strict correlation between these two parameters was no longer obtained, suggesting that a calcium induced calcium release mechanism is necessary for the activation of the contractile proteins by the slow inward calcium current.

Animals↗

PubMed1981

The diagnostic and prognostic value of urinary polyamine measurement in bladder cancer.

This study concerns a group of 54 patients with bladder cancer aged from 51 to 80 years (50 males, 4 females). Polyamines (putrescine -PU, spermidine - SPD) were measured on 24 h urine collections prior to surgery by an automatic ion exchange analyzer. Both polyamines, and especially PU, correlated well with the degree of tumor infiltration (JEWETT - MARSHALL stage) and mitotic activity (BROD -ER'S grade). Retrospectively, 28 patients for whom follow-up after surgery was 6 months to one year were classified into two groups: R+ (21) patients with disease recurrence or progression, and R0 (8) patients remaining tumour free. Twenty patients with high preoperative PU levels were in the R+ group. By contrast, 6 patients with normal preoperative PU levels were in the R0 group.

Follow-Up Studies↗

PubMed1981

California physician's professional image of therapists.

The purpose of this study was to identify the attitudes of California physicians toward the professional image of physical therapists and to determine the influence of several independent variables on that image. A three-part questionnaire was used to survey the sample of physicians. The first two sections contained attitudinal statements based on criteria representing degrees of professionalism; the third section contained questions on demographic variables. The results indicated that, although the majority of responding physicians viewed physical therapists as possessing all of the criteria denoting professionalism, there was relatively less agreement with the two criteria representing the highest degrees of professionalism-evaluative skills and autonomy of judgment. None of the independent variables influenced physicians' professional image of physical therapists except physician specialty area, in which family practitioners held a significantly higher professional image of physical therapists than did neurosurgeons and orthopedists. The authors suggest further study of other factors that may affect physicians' professional image of physical therapists as well as recommend steps that may be taken to improve the professional image of physical therapists.

Attitude of Health Personnel↗

PubMed1980

Slow inward barium current and contraction on frog single muscle fibres.

1. Excitation-contraction coupling process in isolated frog muscle fibres, under conditions which allow the development of a Ba permeability, has been investigated by the simultaneous recording of electrical and mechanical activity. 2. The sustained contraction elicited by a long lasting Ba action potential depends on two mechanisms. The first is potential dependent, the second which is inhibited by MnCl2 (10 mM), depends on the inward flux of Ba ions. 3. The relationship observed between the inward IBa and the peak tension resembles that which has been observed between ICa and the contraction on other muscular structures. 4. The relative tension progressively declines as the intracellular Ba concentration increases and the contractility ends after a series of depolarizing pulses (or Ba action potentials). This indicates that the Ba ions which enter the cell release Ca ions and replace them in the intracellular storage sites. 5. Following a pretreatment with caffeine, the inward IBa fails to induce a contraction. Moreover a muscle which has been loaded with barium until the contraction ceases, does not develop a contracture in presence of caffeine. These results show that the Ba induced Ca release is located at the level of the sarcoplasmic reticulum. 6. Calculations show that the amount of Ba ions necessary to abolish the contractility corresponds to the maximum ability of the sarcoplasmic reticulum for Ca binding. 7. Almost all the inward flux of Ba ions and the contraction are abolished by glycerol-treatment which suggests that the coupling occurs at the T-system level. The results are discussed in regard to the technical limitations of the voltage-clamp method.

Animals↗

PubMed1980

Calcium-dependent electrical activity and contraction of voltage-clamped frog single muscle fibres.

1. The electrical and mechanical activities of isolated frog muscle fibres have been simultaneously recorded under conditions which allow the development of a calcium permeability (chloride-free solution containing 72 mM-calcium levulinate instead of 115 mM-NaCl). 2. Long-lasting calcium action potentials and large and sustained contraction occur without inhibition of the potassium permeability. 3. The relationship observed between the slow inward calcium current and the amplitude of the contraction, under voltage-clamp conditions, resembles that found between IBa and tension in frog skeletal muscle and between ICa and the contraction in frog heart. A part of the mechanical response which is not abolished by manganese seems to be potential-dependent. 4. Integration of the current traces shows that the threshold of the contraction occurs at [Ca]1 near to 2.10(-6) M and that the contractile proteins are fully activated at [Ca]1 near to 10(-4) M, values which are in good agreement with those proposed by other authors. 5. The minimum calcium influx necessary to induce a detectable contraction is close to 4.8 p-moles/cm2. This value is 10-20 times larger than the calcium influx measured during a normal action potential. 6. On detubulated fibres the calcium permeability fails to develop: this indicates that this current originates from the T-system. The close correspondence between ICa and the contraction, and between the time course of the contraction at the end of the depolarizing steps suggests that the potential of the tubular membrane is better clamped than in normal physiological conditions.

Animals↗

PubMed1980