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Biomedical subjects

M Aoki

Publications and source records attributed to M Aoki.

At least 703 records · Page 39Linked to original sources
PubMed1988

[Dental arch form achieved by orthodontic treatment].

The objective of this study was to compare the dental arch forms of a control group with normal occlusion to the finished dental arch forms achieved by orthodontic treatment. The data consisted of 185 Japanese males and 275 Japanese females. These sex groups were divided into three groups, i.e., a group treated by extraction of the four first premolars, a group treated by non-extraction method and a control group consisting of individuals with normal occlusion. Findings were as follows: 1. The position of each tooth showed a normal distribution, with a small range of variation in all groups. 2. There were no significant differences in the range of tooth distribution among the three groups in each sex. However, the measurement of the male values were larger than those for the females. 3. In comparison with the other two groups, the transversed width between the same number of teeth of the extraction group had a larger width in the anterior teeth segment and a smaller width in the posterior teeth segment. The non-extraction group had a larger width in all of the teeth segment except for the second molars, than for control group. There were significant differences in all of the teeth between the males and the females. 4. As a result of a qualitative and a quantitative examinations, it was determined that the dental arch forms were almost the same among the three groups for each sex. The dental arch became progressively longer in the following successive order for the extraction group, the control group and the non-extraction group. 5. Except for the intercanine width, the dental arch forms of the Japanese group were wider and longer than that of the Caucasian North American group. In spite of the variation of the genetic background in respect to the differences of the ethnic background and sex, it was confirmed that there were no noticeable differences in the dental arch forms between the orthodontically treated groups and the non-treated group with normal occlusion.

Dental Arch↗
PubMed1987

Effects of different schedules of progesterone treatment on mammary tumorigenesis and uterine adenomyosis in SHN virgin mice.

As a possible step to estimate the factors controlling the effects of progesterone on mammary tumorigenesis, 3 groups of SHN virgin female mice were treated as follows beginning 2.5-4 months of age: Group A received the subcutaneous implantation of silastic tube containing progesterone (low dose) during the initial 4 months followed by progesterone pellet implantation (high dose) every 2 months. Group B was implanted with progesterone pellet throughout the experiment. Group C was given the vehicle only. Whereas there was little difference among groups in mammary tumorigenesis during the initial 4 months of treatments, tumorigenesis was significantly stimulated in group B thereafter. On the contrary, group A was different little from group C even after progesterone pellet implantation. The results indicate that the effects of progesterone on mammary tumorigenesis are affected by the 'preceding' progesterone conditions and that there is a critical period for manifestation of the effects of progesterone on mammary tumorigenesis, which is before 8 months of age at most. While all mice developing mammary tumors developed uterine adenomyosis in each group, the progression was enhanced by both low and high doses of progesterone.

Animals↗
PubMed1987

The properties of goal-directed eye movements evoked by microstimulation of the cerebellar vermis in the cat.

The properties of eye movements evoked by microstimulation of the cerebellar vermis, lobules V VII, were investigated in encéphale isolé cats. The evoked eye movements tended to reach the same final goal in the orbit irrespective of initial eye position. The goal position depended on stimulus intensity. In contrast with the monkey, the goal of the eye movement lay within the oculomotor range. The goal position of the eye movements evoked by simultaneous stimuli delivered to two sites corresponded with the point which was obtained by the vectorial addition of the two eye movements evoked by the stimulation of each site. These findings suggest that the cat vermal lobules V VII play an important role in the control of horizontal and vertical eye position in the orbit.

Animals↗
PubMed1987

Long-term storage of blood samples at freezing temperatures in the presence of a cryoprotectant for hemiglobin assay.

Changes in Hi levels in experimentally prepared blood samples during storage at various temperatures were studied. When whole blood in which Hi levels were elevated by sodium nitrite was stored unfrozen, rapid reduction of Hi was observed within 24 hr even at 0 degrees C. When whole blood or a diluted hemolysate was stored frozen for a week or longer, considerable formation of Hi by autoxidation was observed, the formation at -20 degrees C being much more significant than that at -30 degrees C. On the other hand, addition of an equal volume of the cryoprotectant solution of Rowe et al. to blood almost completely inhibited this Hi formation during freezing storage until at least 30 days. Thus, a new method for long-term storage of blood samples for Hi assay was devised.

Blood Preservation↗
PubMed1987

Computer simulation of the Wolff-Parkinson-White syndrome utilizing a human heart model.

The relationship between the location of an accessory pathway and body surface ECG waveforms was investigated by computer simulation of the WPW syndrome using a human heart model. The 3-dimensional heart model is composed of 50,000 units so as to represent the details of ventricular excitation. Ten typical accessory pathways near the A-V groove were examined, which correspond to Gallagher's classification of the WPW syndrome based on their surgical experience. Twelve-lead ECG waveforms were calculated for these 10 cases and were compared with the clinical observations of Gallagher et al. The polarities of the delta waves at 40 msec after the onset of the QRS were listed. The agreement of our model with the clinical data obtained by Gallagher et al is 87%. Details of changes in the ECG waveforms were also examined by changing ther terminal location of the accessory pathway along the radial and longitudinal directions in the ventricles, and it was found that the ECG waveforms of the limb leads are more sensitive to this difference in the preexcited location than those of the chest leads. The simulated epicardial isochronic patterns also agree with the measurements.

Computer Simulation↗
PubMed1987

[Chronic oral toxicity study of proglumetacin maleate in beagle dogs].

A chronic oral toxicity test of proglumetacin maleate (PGM), an anti-inflammatory agent, was studied at dose-levels of 0, 0.6, 2.5 and 10.0 mg/kg/day using male and female beagle dogs. They were treated for 12 months, followed by 1 month recovery period. Excretion soft and mucous feces was observed in females of 2.5 mg/kg/day group. In addition, excretion of diarrheal and blood-tinged feces was also found in females of 10.0 mg/kg/day group. One female animal given 10.0 mg/kg/day of PGM was found dead on day 178 of administration. For about a month before death, diarrheal and blood-tinged feces, decreases in body weight and food consumption, and anemia had been noticed. At the autopsy, brown-cloudy ascitic fluid, adhesion of visceral organs, hyperemia or hemorrhage in the mucosa and serosa of the digestive tract, and an ulcer in the duodenum were found. No significant influences of PGM were noted on the changes of body weights, food and water consumptions, excluding the dead animal. A fecal occult blood test showed an increase in no. of animals with blood-positive reaction in 2.5 and 10.0 mg/kg/day groups of both sexes, especially marked in females of 10.0 mg/kg/day group. In urinary tests, no significant changes were found in any of the PGM-treated groups of both sexes; the dead one, however, showed decreases in urine volume and electrolyte excretion on month 6 of administration. No significant hematological changes associated with the administration of PGM were found in any of the animals excluding the dead one, in which anemia and inflammation-related findings were found on month 6 of administration. Serum-biochemical tests showed no significant changes in any of the PGM-treated groups of both sexes. No significant influences of PGM were found on ICG and PSP clearances, ocular fundus and ECG. At the autopsy performed at the end of administration, no significant changes were found in any of the PGM-treated groups of both sexes. Histopathologically, a duodenal ulcer and peritonitis-related findings were observed in the female dead animal of 10.0 mg/kg/day group. No influences of PGM were found in any of the tests performed at the end of the recovery phase. From these results, the non-effective dose of PGM was estimated to be 0.6 mg/kg/day, and the toxic doses of PGM to be more than 10.0 mg/kg/day for males and 10.0 mg/kg/day for females, respectively, in beagle dogs treated orally with PGM for 12 months.

Administration, Oral↗
PubMed1987

[Distribution pattern of lumbar epaxial, especially M. multifidus motoneurons in the spinal cord of the cat: a study by the retrograde horseradish peroxidase method].

Distribution patterns of motoneurons supplying the lumbar epaxial muscles in the spinal ventral horn have been investigated by the retrograde horseradish peroxidase (HRP) method in 6 cats. HRP (30-40%, 3.0-5.7 mg) injections into multifidus muscle in 5 cases, and for comparison, longissimus lumborum muscle in one case were made at vertebral levels from L5 to L7 at multiple sites. After two days, the animals were sacrificed and frozen sections (60 microns thick) in the frontal plane of the spinal cord were made from the L1 to L7 segments and each section reacted histochemically with the tetramethylbenzidine (TMB) method. The results are summarized as follows. Following HRP injections into the multifidus muscle, labeled cells were found in the ventral horn rostrocaudally from the L2 to L6 segments. Total number of labeled cells ranged from 176 to 436 on the injected side. Labeled cells were most numerous in the L4 segment (range: 98-244). Labeled cells were found on the medial side of the ventral horn, especially in the ventromedial part (VM), predominantly ipsilateral to the injected muscle. Following HRP injection into the longissimus lumborum muscle in one case, labeled cells were also found on the medial side, but were more restricted in the centromedial part (CM) of the ventral horn. In all cases with HRP injection into the multifidus muscle, labeled cells were occasionally observed in VM and/or the medial ventral column (VC) contralateral to the injected muscle in L3 and/or L4 segment. The total number of these cells ranged from 2 to 66. These contralaterally labeled cells were presumed to be due to the peripheral HRP spread. Labeled cells observed in VM and CM were fusiform and round in shape, respectively. These cells had mean average soma diameters (ASD) from 32 to 40 microns and were presumed to be alpha motoneurons. A few labeled cells observed in VC were fusiform in shape and were significantly smaller (mean ASD: 23-28 microns) than the cells observed in other areas (VM, CM). In some cases, the dendrites of labeled cells in VM and VC extended dorsomedially in the VC across the midline in the anterior white commissure.

Animals↗
PubMed1987

[Malignant germ cell tumors in the mediastinum].

Mediastinal germ cell tumors are divided into seminomas and non-seminomatous germ cell tumors. The former is a radiosensitive tumor that can be successfully treated by surgery and radiation. The latter is much more malignant than the former, however, the therapy has been making remarkable progress owing to CDDP. Nevertheless, the median survival time of patients with mediastinal involvement is 14 months, much lower than that seen in patients with testicular involvement. From our 12 patients and a review of the literature, we drew the following conclusions. If malignant germ cell tumors are suspected among anterior mediastinal tumors affecting male patients of around 20 years old, tumor markers such as AFP and HCG must be investigated and then, tissue histology should be diagnosed from specimens obtained by mediastinoscopy or anterior mediastinotomy. In the case of NSGCT, or AFP and/or hCG producing seminoma, the first choice is the chemotherapy including CDDP. Seminomas, that do not produce either AFP or HCG, can be treated by surgery and radiation. If the patients have tumor markers such as AFP and/or HCG, these are very useful to evaluate the efficacy of the therapy. When the efficacy of chemotherapy reaches the maximum, adjuvant surgery may be indicated. Chemotherapy should be continued, when malignant tissues are present in the resected mass.

Adolescent↗