Threshold changes of the jaw-opening reflex by the impulses of afferent nerve fibers for conveying electroacupuncture analgesia in rats

The effects of the conditioning electrical stimuli applied directly to the nerves (45 Hz, 0.1 ms, 15 min) innervating the meridian points of Yin-Hsiang (infraorbital nerve), Ho-Ku (radial nerve) and Zu-Sanli (common peroneal nerve) on the pulp-evoked jaw-opening reflex were investigated in the Wistar albino rats. The threshold change of the digastric electromyogram activity in the reflex was monitored during and after the conditioning stimulation. There was a gradual change in the threshold and the effect remained for several minutes after the cessation of the conditioning stimulation. In case of stimulating each ipsilateral nerve, the effective degree was 210 to 260% of the control. On the other hand, when each contralateral nerve was stimulated, the degree was 170 to 200% of the control. The reflex was also evoked by the low intensity of the direct infraorbital nerve stimulation. The threshold value of this reflex was not altered by the conditioning stimulation of each nerve.

Responses of raphe magnus neurons to systemic morphine in rats

The spontaneous firing rate of nucleus raphe magnus (NRM) neurons increased, decreased or were not altered in Wistar rats after various doses of morphine were administered intravenously. Dose-related changes were observed only in neurons which displayed increased firing frequency. Naloxone antagonized the morphine-induced effect more frequently in the excited neuron than in the inhibited one. These results suggest that morphine induced increases in discharge frequency is the more specific pharmacological effect, and that only the excited neuron might participate directly in the descending analgesic system of morphine.

Developmentally regulated glycoprotein alterations in Dictyostelium discoideum

We have studied the changes in glycoprotein patterns on the surface of Dictyostelium discoideum cells during development on a membrane filter and in suspension culture. Cell-surface carbohydrates were detected by a periodate-[3H]borohydride method. The appearance and the increase of some glycoproteins during the early developmental stage on a membrane filter were induced 6 h after the onset of starvation. In suspension culture the same proteins appeared about 2 h earlier and less copies per cell were made. Some glycoproteins present in growth-phase cells, especially with high molecular weights, partially disappear during development on a membrane filter. However, the latter changes were not observed in suspension culture. Pulses of cAMP, which generally accelerate cell development, induced only the appearance of one glycoprotein. We conclude that the changes in patterns of plasma membrane glycoproteins during early development are regulated by several factors; starvation, pulses of cAMP, cell-cell contact and transfer onto a membrane filter.

Jaw opening reflex affected by electroacupuncture in rat

In rats, the jaw opening reflex to tooth pulp stimulation was suppressed, but that to lower lip stimulation was scarcely affected by electroacupuncture stimulation of the forefoot. After transection of the spinal trigeminal nucleus at the obex level, the magnitude of the reflex to tooth pulp stimulation was greatly decreased and electroacupuncture was less effective on the pulp-evoked reflex. By contrast, the reflex activity to lower lip stimulation was not altered after the transection. The present study suggests that the site of action of electroacupuncture on the jaw opening reflex is in the caudal part of the spinal trigeminal nucleus and that pulp evoked jaw opening reflex is a presumed nocifensive response.

Drastic changes in accumulation and synthesis of plasma-membrane proteins during aggregation of Dictyostelium discoideum

Protein compositions of plasma membranes of Dictyostelium discoideum and their developmental changes during aggregation were analyzed by two-dimensional polyacrylamide gel electrophoresis. More than 150 polypeptide species could be detected with the growth-phase cells by staining. Most of them (about 120 spots) were conserved during aggregation, although their relative intensities of staining changes. On the initiation of cell differentiation, new polypeptides were accumulated on the plasma membrane and at least 110 new polypeptides were detected at the late-aggregation stage. This accumulation of new components was completely inhibited when the growth-phase cells were incubated in a liquid medium containing 5 mM EDTA. Studies on protein synthesis suggested that the accumulation and appearance of the new protein components was due to de novo synthesis. Pulse-label experiments with [35S]methionine showed that out of 200 proteins detected during aggregation, about 90 proteins showed various stage-specific patterns of synthesis and the rest were synthesized consistently. Actin and discoidin present in the plasma membrane were identified by reference to purified actin and discoidin. Actin synthesized de novo accumulated progressively on the plasma membrane during aggregation. Discoidin also accumulated on the plasma membrane, but a large amount was also recovered in a cytoplasmic soluble fraction. Discoidin I was separated into two spots with different pI values on a two-dimensional gel.

Inhibitory actions produced by local electrical stimulation in the caudal spinal trigeminal nucleus in rat

Inhibitory actions induced by local electrical stimulation (LES) on the tooth pulpal afferent activities were investigated in the caudal part of the rat spinal trigeminal nucleus. For the LES, ipsilateral Yin-Hsiang (intrasegmental point) or Ho-Ku (extrasegmental point) was used as a cathodal point which was stimulated electrically by a single pulse of 0.1 msec in duration or by 0.1 msec-pulse train at 45 Hz for 15 min. We found at least three types of inhibitions in the caudal trigeminal nucleus: Type I--this inhibition is the most forceful, caused by naloxone-reversible endogenous opiate system with a slow onset and prolonged aftereffect. This inhibition is presumably postsynaptic action. Type II--this is evoked by postsynaptical acting inhibition and begins within milliseconds after the stimulus is applied. Type III--this inhibition is elicited by presynaptic action and also begins within milliseconds after the onset of the stimulation. Type I and II inhibitions are evoked by stimulating either intra- or extrasegmental LES points, however, Type III is produced by stimulation of intrasegmental and rarely provoked by extrasegmental point stimulation. Naloxone failed to reverse Type II and III inhibitions. During LES, Type I to III inhibitions co-work for producing the suppressive effect and after the cessation of its stimulation, only Type I inhibition produces the so-called aftereffect of the LES.

[A comparative study on the prevalence of pleural thickness related with asbestos exposures. A comparison between urban and rural districts using miniature X-ray films (author's transl)]

Using miniature films for mass tuberculosis examination of inhabitants, a comparison was made of the prevalence of pleural thickening between urban and rural districts in Japan. The classification of pleural thickening mostly followed the criteria of Askergren and Szamosi. Age adjusted prevalences for male adults were 2.7% (Ys city) and 5.3% (Yk city) in urban districts, and 0.7% (Hokuriku district) in rural districts. In addition to the survey of these inhabitants, workers of a ship building factory in the urban district were examined. Age adjusted prevalence in this case was 7.3%. On the other hand, the prevalence for female adults were 0.2% (Ys city) and 0.4% (Yk city) in the urban districts, and 0.09% in the rural districts. The prevalence of pleural thickening showed a sharp increase after 60 years of age in male adults but not in female adults. It was confirmed that pleural calcification was a better diagnostic feature for distinguishing the difference of prevalence by areas.

Peripheral afferent nerve impulses for conveying electroacupuncture effects on the jaw opening reflex evoked by tooth pulp stimulation in rat

Effects of conditioning electrical stimulation of the nerves innervated around the meridian Ho-Ku point on the tooth-pulp evoked jaw opening reflex were investigated in Wistar albino rats. Changes of the threshold of the reflex were monitored before and after the conditioning stimulation. The increased changes of the threshold value gradually appeared and even after the cessation of the conditioning stimulation, its effect remained for several minutes. Of the three nerves in the brachial plexus (radial, median and ulnar), radial nerve was the most effective. The ipsilateral nerve stimulation was more effective on the threshold elevation of the reflex than the contralateral one. When the two nerves were stimulated simultaneously, the increase of the threshold value was sometimes observed as compared to the case of stimulating each nerve separately. However, in cases of the combination stimulation including radial nerve, the summation among the different impulses produced by the conditioning stimulation was scarcely observed; therefore, the effect was not reinforced.

Changes of the jaw opening reflex activity by electroacupuncture stimulation in rat

After electroacupuncture stimulation applied to bilateral Ho-Ku points in the rat forepaw, jaw opening reflex to tooth pulp stimulation was fairly suppressed, but that to gingiva, upper lip or lower lip stimulation was scarcely affected. By direct stimulation of afferent sensory pathway in the spinal trigeminal nucleus, jaw opening reflex was also evoked. Suppressive effects of electroacupuncture were more markedly observed when the jaw opening reflex was evoked by stimulating the caudal part of the spinal trigeminal nucleus than when the reflex was evoked by stimulation of the rostral area of the nucleus. One of the main action sites of the electroacupuncture on the jaw opening reflex was the caudal spinal trigeminal nucleus, which is the secondary neuron level in the trigeminal noxious sensory pathway, suggesting that electroacupuncture can provoke the pain suppressive effects strongly in the lower part of the brain with the higher brain function being intact. Therefore, this observation is thought to be well coincident with clinical data that acupuncture produces analgesia without affecting patients' consciousness during surgical operations.

Morphine and electroacupuncture: comparison of the effects on the cortical evoked responses after tooth pulp stimulation in rats

The effects of morphine and electroacupuncture on the cortical evoked responses after tooth pulp stimulation were investigated in rats. Morphine suppressed these responses more strongly in secondary somatosensory areas than those in primary somatosensory areas, while electroacupuncture suppressed the responses to the same degree in both areas. These results might suggest that there are some differences in noxious-suppressive action between morphine and the endogenous opiates released by electroacupuncture stimulation.

Electroacupuncture suppression of the rat jaw opening response after stimulating the caudal spinal trigeminal nucleus

Suppressive effects of electroacupuncture on the jaw opening responses evoked by stimulation of two areas (anterior and posterior) within the caudal spinal trigeminal nucleus were investigated using lightly anesthetized rats. Electroacupuncture stimulation markedly suppressed the jaw opening responses evoked by stimulating the posterior area, but suppressed only slightly those evoked by stimulating the anterior area.

Surface labeling of membrane glycoproteins and their drastic changes during development of Dictyostelium discoideum

Surface glycoproteins on plasma membranes from Dictyostelium discoideum were labeled by sodium metaperiodate oxidation and sodium boro[3H]hydride reduction. The amount of incorporation of tritium from NaB3H4 reached a plateau after 10 min at a periodate concentration of 20 mM. The density analysis carried out by sucrose density-gradient centrifugation showed that the plasma membranes were selectively labeled by this technique. About 84% of the radioactivity incorporated was released by hydrolysis with 0.25 M H2SO4 for 3 h at 100 degrees C. The released materials were eluted at a bed volume after chromatography using a Sephadex G-50 column. From the paper chromatographic analysis of the eluate, four radioactive spots were detected. Two of them were glycerol and glyceraldehyde and the other two spots seemed to be oligosaccharides. Using the above method, the plasma membranes from aggregation-phase cells were labeled four times more than those from growth-phase cells. The labeled plasma membrane fraction during the aggregation phase was separated into at least 39 distinct glycoprotein bands on a one-dimensional dodecylsulfate/polyacrylamide gel. Six of the 39 bands increased markedly in density and two new bands appeared. In contrast, four bands decreased in density in the aggregation phase. Using this method, the surface glycoproteins can be analyzed directly be gel electrophoresis of the lysate of labeled whole cells without preparing the plasma membranes. Changes during development of glycoproteins on outer cell surfaces were also confirmed by O'Farrell's method of two-dimensional polyacrylamide gel electrophoresis. Utilizing this technique, glycoproteins on plasma membranes of D. discoideum were separated into 63 individual spots; 45 of these 63 spots changed during the early developmental course of D. discoideum. This is in contrast to the slight change in the soluble and membrane proteins during this phase. This fact also suggests that the glycoproteins have important roles in the process of aggregation.

Effective conditions of electroacupuncture stimulation for suppressing tooth pulp-evoked jaw-opening reflex in the rat

The effects of electroacupuncture (EA) on the rat jaw-opening reflex elicited by tooth pulp stimulation were studied to decide the effective stimulus conditions for electroacupuncture stimulation (EAS). The present study revealed that one of the most important factors for producing a strong EA effect was the stimulus pulse-frequency and that the stimulus pulse-duration was not an essential factor for this effect. In the rat, the following stimulus conditions were very useful for the quantitative study of the EA effect. (1) Stimulation time is 15 min. (2) Stimulus pulse-frequency is 30 to 150 Hz. (3) Stimulus pulse-duration is 0.1 to 5 ms. When the EAS was applied to the Ho-Ku point under these conditions, the degree of the suppression of the jaw-opening reflex was about 50% of the control.

Papillary adenoma of the duodenum; report of a case and review of the literature in Japan

A papillary (villous) adenoma of the duodenum was found in a 67-year-old male. Radiographic barium studies of the upper gastrointestinal tract revealed a tumor in the second portion of the duodenum. Biopsied specimens taken through a duodenofiberscope showed papillary adenoma. A partial duodenectomy with duodenojejunostomy was performed. The specimen was a pedunculated tumor measuring 3 X 2 X 1.5 cm. Histologically, the tumor was composed of villous and tubular arrangements of mucus-secreting columnar epithelial cells. A moderate number of entero-endocrine cells and a few Paneth cells were also noted. Forty-two other cases reported in Japan are briefly reviewed.

Quantitative relation between the intensity of tooth pulp stimulation and the magnitude of jaw opening reflex in the rat

The stimulus-response relation in the jaw opening reflex evoked by tooth pulp stimulation, which is considered as a "pain index", follows the power function with an exponent of about six over a range of lower stimulus intensities.

Quantitative relations between noxious stimulus intensity and magnitude of central afferent evoked responses in rat

Relations between intensities of electrical noxious stimulus applied to the tooth pulp and magnitudes of evoked responses at various relay stations of tooth pulp afferents were investigated with lightly anesthetized rats. The stimulus-response function in each relay station and the cerebral cortex follows the power function only in the range of lower, but noxious, stimulus intensities; however, it deviates from it in the range of higher ones, the exponent of the function becoming smaller. The higher the relay station locates, the smaller the exponent value is.