Effect of electro-acupuncture (EA) on the jaw opening reflex induced by tooth pulp stimulation was investigated in Wistar albino rats. The amplitude of the digastric muscle EMG (dEMG) evoked by stimulation of the lower incisor tooth pulp was measured as the magnitude of the reflex and estimated as an indicator of the EA effect. Acupuncture needling was given at one meridian point of Ho-Ku and two other nonmeridian points in one forepaw. Compound action potentials of ulnar, median and radial nerves elicited by 15 min EA stimulation at 45 Hz through the needling points were recorded from the brachial plexus innervating the same acupunctured forepaw. Of the above-mentioned three nerves, the afferent volleys in the radial nerve were found to be the most effective to suppress the dEMG during EA stimulation. The EA stimulation of the Ho-Ku point showed a greater effect than that of nonmeridian points. There was a significant correlation between the amplitude of Abeta fibers in the compound action potentials elicited by EA stimulation and the dEMG suppression. To confirm the so-called morphine-like action of EA that has recently been proposed, levallorphan (LORFAN), antagonist of morphine, was administered before and after EA stimulation. In the premedicated case, no suppression of the dEMG occurred. In the postmedicated case, on the contrary, the dEMG responses which were reduced during 15 min EA stimulation recovered more rapidly than in the case without LORFAN. These results suggest that the afferent impulses conducted along Abeta fibers mainly in the radial nerve cause the release of endogeneous morphine-like substances in specific central nervous areas for suppressing the dEMG activity.

Action Potentials↗

PubMed1977

Phenylalanine hydroxylase deficiency in the peripheral lymphocytes from phenylketonuria.

A radiograph of the incorporation of 3H-phenylalanine and 3H-tyrosine into cultured lymphocytes in a phenylketonuria patient indicates phenylalanine hydroxylase deficiency in the peripheral lymphocytes. Cultured lymphocytes from the patient showed much less uptake of 3H-phenylalanine and a slightly higher incorporation of 3H-tyrosine than the control. It is possible that a lack of phenylalanine hydroxylase in the peripheral lymphocytes of PKU patients prevents oxidation of phenylalanine to tyrosine.

Autoradiography↗

PubMed1977

[Studies on Stevioside, natural sweetener. Effect on the growth of some oral microorganisms (author's transl)].

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Bacteria↗

PubMed1977

[Pick's disease].

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Dementia↗

PubMed1976

Invertase biosynthesis by Saccharomyces carlsbergensis in batch and continuous cultures.

The biosynthesis of invertase by Saccharomyces carlsbergensis LAM 1068 was studied in relation to its glucose effect at both unsteady and steady states of growth. Experimental correlations between the dilution rate and invertase specific activity (E/X) in chemostat cultures led to an optimum for the enzyme synthesis at a particular intermediate growth rate. The value of E/X increased from 1.1 (U/mg biomass) in batch cultures to 13 (U/mg biomass) in chemostat cultures. A mutant strain A3 showed the highest value for E/X = 25 (U/mg biomass) at high dilution rates where glucose repression was observed with the wild strain.

Enzyme Repression↗

PubMed1976

Dual control of invertase biosynthesis in chemostat culture.

In a previous study on the chemostat culture of Saccharomyces carlsbergensis, maximum invertase specific activity was observed at an intermediate dilution rate. A possible regulation mechanism, assuming there are simultaneous effects of induction and repression on two sites of the operator loci for invertase formation, is proposed which might account for the observed curve of the dilution rate effect.

Enzyme Induction↗

PubMed1976

Transfer mechanism of melanosomes in epidermal cell culture.

The mode of melanosome transfer from melanocytes to keratinocytes in epidermal cell cultures has been examined with time-lapse cinematography and electron microscopy. A tip of a melanocyte dendrite containing melanosomes became enfolded by a recipient keratinocyte. It was then pinched off to form a cluster of melanosomes which initially seemed to be surrounded by two layers of membranes. The phagocytized dendrite was gradually decomposed and became an aggregate of melanosomes surrounded by a single membrane of the keratinocyte. The individual melanosomes were dispersed from the aggregate into the keratinocyte cytoplasm, depending on the size of melanosomes. The larger ones were single and smaller ones were complex. The mechanism of melanosome transfer in vitro is a type of cytophagocytosis. The entire process consists of two steps: the first is a cytophagic process and the second a melanosome dispersion process. The process is influenced by various exogenous factors.

Cells, Cultured↗

PubMed1976