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Biomedical subjects

M Hong

Publications and source records attributed to M Hong.

At least 163 records · Page 9Linked to original sources
PubMed1989

[Condylo-pterygo-maxillo-oblique tomography].

This is a new projection method for TMJ examination. In this film, not only the structures of the joint but also the surrounding structures were manifested. These included the internal and external articular tubercles, internal and external poles of the condylar head, pterygoid process, and the posterior portion of dental occlusion. Particularly, the external pterygoid muscle is manifested in this film. The above mentioned features could not be found in Schüller's film. It is obvious that the combined CPMO tomography with Schüller's film will be a perfect method of TMJ examination. The details of the projection technique are described and discussed.

Adolescent↗
PubMed1989

[Damage to the development of the rat brain by severe iodine deficiency and the protective effects of thyroid hormone].

The detrimental effects of iodine deficiency on brain development and the protective effects of thyroid hormone replacement therapy in the critical period were closely examined. Animals in the experiment were divided into four categories: Normal control (NL), Low iodine diet group (LI), Normal iodine diet group (NI) and the thyroid hormone supplement group (LI+T). Results showed that the body weight, motility and the indices of learning ability including total time (TT), the number of conditioned reflex (CL), conditioned and unconditioned reflex latency and the correction rate of conditioned reflex in the LI+T were all improved to such a condition that there was no significant difference between the LI+T and N, NI. (P greater than 0.05), whereas there did have significant difference between LI+T and LI (p less than 0.01). The experiment confirmed the protective effects offered by the thyroid hormone from damaging by severe iodine deficiency.

Animals↗
PubMed1988

The effect of long-term treatment with amine-depleting drugs or chlorpromazine on alpha-adrenoreceptors and 5-HT2 receptors in the brain of the rat.

The effect of chlorpromazine, oxypertine, tetrabenazine or reserpine on alpha-adrenoreceptors and 5-HT2 receptors in the brain of the rat was studied both in vitro and after the administration to animals for up to 12 months. In vitro, chlorpromazine and oxypertine potently displaced the specific binding of [3H]WB 4101 to alpha 1 adrenoreceptors in the cortex and of [3H]ketanserin to 5-HT2 receptors in the frontal cortex. Both drugs were moderately effective in displacing the specific binding of [3H]clonidine from cortical alpha 2-adrenoreceptors. Tetrabenazine only weakly displaced the specific binding of [3H]WB 4101, [3H] clonidine and [3H]ketanserin. The incorporation of reserpine into tissue incubates had little effect on the binding of any of these ligands. Administration of chlorpromazine (33-36 mg/kg/day) to rats for up to 12 months reduced the number of specific binding sites (Bmax) for [3H]ketanserin in the frontal cortex, but did not alter the specific binding of [3H]WB 4101 or specific [3H]clonidine to cortical membranes. In contrast, treatment with oxypertine (6.3-7.3 mg/kg/day), tetrabenazine (6.0-6.7 mg/kg/day) or reserpine (0.28-0.30 mg/kg/day) increased the Bmax for the specific binding of [3H]WB 4101, but did not alter the specific binding of [3H]clonidine or [3H]ketanserin. Oxypertine resembles chlorpromazine in its ability to interact with alpha-adrenoreceptors and 5-HT2 receptors in brain. Tetrabenazine and reserpine have few direct actions on post-synaptic monoamine receptors. However, on long-term administration, oxypertine, like tetrabenazine and reserpine, predominantly altered alpha 1-adrenoreceptors, whereas chlorpromazine influenced the population of 5-HT2 receptors.

Animals↗
PubMed1987

Effects of continuous administration for 12 months of amine-depleting drugs and chlorpromazine on striatal dopamine function in the rat.

Rats received either chlorpromazine (33-36 mg/kg/day), oxypertine (6.3-7.3 mg/kg/day), tetrabenazine (6.0-6.7 mg/kg/day) or reserpine (0.28-0.30 mg/kg/day) continuously for up to 12 months. Chlorpromazine and tetrabenazine reduced spontaneous locomotor activity of animals after 1 month of treatment. Thereafter, locomotor activity in animals treated with chlorpromazine returned to control levels, whereas treatment with tetrabenazine increased locomotion. Oxypertine enhanced spontaneous locomotor activity after 9 months of administration only, whereas treatment with reserpine did not alter this activity at any time during the study compared to age-matched controls. Treatment with tetrabenazine enhanced stereotyped behaviour induced by apomorphine (0.063-1.0 mg/kg s.c.) throughout the study. In contrast, stereotypy in animals administered chlorpromazine, oxypertine or reserpine was the same as in control animals throughout the 12 months of treatment. Levels of dopamine in the striatum were reduced after the first month of administration of chlorpromazine, but thereafter returned to control values. Treatment with oxypertine for up to 12 months did not alter concentrations of dopamine in the striatum, whereas administration of tetrabenazine and reserpine caused a decrease. All treatments with drugs consistently reduced the content of homovanillic acid in the striatum during the study. The Bmax for specific binding of [3H]spiperone in the striatum was increased by continuous treatment of animals with chlorpromazine, oxypertine or tetrabenazine, although the effects of oxypertine and tetrabenazine were only transient. Administration of reserpine did not alter the Bmax for specific binding of [3H]spiperone. The Bmax for specific binding of [3H]piflutixol in the striatum was unchanged by any treatment for up to 12 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗