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Biomedical subjects

T Morimoto

Publications and source records attributed to T Morimoto.

At least 811 records · Page 45Linked to original sources

Reflex activation of extrinsic tongue muscles by jaw closing muscle proprioceptors.

Depression of the mandible in the decerebrate cat induced retraction of the tongue. The mechanism of this jaw-tongue reflex was analyzed by recording electromyographic activity from the temporal and styloglossal muscles as representative masticatory and extrinsic tongue muscles, respectively. Tongue muscle activity was elicited when the mouth was opened beyond 10 degrees while the threshold for the masticatory muscle activities was around 2 degrees. Neither sectioning of the masseteric nerve nor anesthetization of the temporomandibular joint capsule affected the tongue muscle activities. In contrast, exfoliation of the temporal muscle from the temporal bone greatly reduced the effects of jaw depression. When the isolated coronoid process of the mandible was stretched downwards, activities were evoked in the tongue muscle. Repetitive electrical stimulation at a frequency of 100 Hz to the temporal nerve activated the tongue muscle, and the threshold of reflex activation was between 1.3 and 1.7 times threshold of the temporal nerve. Vibratory stimuli applied to the mandible at frequencies below 130 Hz were also effective in evoking tongue muscle activity. However, when the frequency was above 135Hz, tongue muscle activity was not induced although activity was still observed in the masticatory muscles. These results indicate that the jaw-tongue reflex is elicited mainly by proprioceptors in the temporal muscle, and that they may probably be the Golgi tendon organs and the secondary endings rather than the primary endings of the muscle spindle.

Animals↗

Therapeutic value of mepitiostane in the treatment of advanced breast cancer.

A new, orally active antiestrogenic steroid, mepitiostane (20 mg/day), was given to 45 patients with advanced breast cancer. The regression rate was 31.1%, or 14 of 45 patients, and a duration of regression of greater than 6 months was obtained in seven patients. Virilizing effects such as hoarseness, hirsutism, and acne were observed relatively often, but there was no evidence of abnormality in the liver function tests or in the serum calcium level.

Androstanes↗

Asymptomatic transient hyperamylasemia after a large intravenous dose of steroid hormone.

Asymptomatic transient hyperamylasemia accompanied with hyperamylasuria immediately after an intravenous dose of 1 gm methylprednisolone has been observed in renal homotransplantation patients. Similar phenomena have also been seen in the other operative patients who received certain amounts of steroid hormone intravenously during their procedure. These cases of hyperamylasemia and hyperamylasuria were studied in detail including time-sequence observation, amylase-creatinine clearance ratio, and amylase isoenzyme analysis. The hyperamylasemia is not due to the general anesthesia or the surgical procedure. It is apparently not due to simple retention of enzyme from poor kidney function. The source of hyperamylasemia is the pancreas mediated by large intravenous doses of steroid hormone.

Aged↗

Long-term changes in the perception of comfortable mandibular occlusal positions.

The aim of this study was to disclose, whether use of a screw jack device to set the distance between the jaws, would contribute towards a stabilization of the magnitude and position of a comfortable zone of mandibular positions or even eliminate it. Thirteen subjects participated in each of fifteen experimental sessions distributed over a 3-week period. Throughout the investigation the zone prevailed at an average width of 1-3 mm. The gap shrank 0-08 mm on average per experimental session. Although this latter value was found to be significant statistically, it can hardly be of clinical importance, considering the time needed for a total contraction of 0-8 mm to develop.

Aged↗

Dimension discrimination at two different degrees of mouth opening and the effect of anaesthesia applied to the periodontal ligaments.

The dimension discrimination ability of twenty-five young persons was tested at two different degrees of mouth opening. One reference stick of 10-0 mm and another of 45-0 mm was placed between the teeth, alternating with test sticks of different heights. The subjects were asked to assess whether a test stick felt higher or lower than the reference stick. The experiment was performed with and without anaesthesia applied to the periodontal ligaments. Anaesthesia did not impair the discrimination ability. At dimensions in the region of the 10-0 mm stick the incorrect assessments occurred predominantly among sticks higher than the reference stick. Around the 45-0 mm stick incorrect assessments were distributed evenly between dimensions higher or lower than the reference stick.

Adult↗

Experimental studies on vertical infection of mice with Japanese encephalitis virus. II. Effect of inoculation route on placental and fetal infection.

Studies were made on the effect of the route of inoculation on the establishment of experimental vertical infection of mice with Japanese encephalitis virus. Mice of the three strains, CFW, C3H/He, and C57BL/6, were inoculated with a field strain of the virus by the intravenous, intraperitoneal, or subcutaneous route. An attempt was made on them to recover the virus from the placenta and fetus. As a result, there were differences in rate of plancental and fetal infection among the route of inoculation. It was dependent the establishment of vertical infection. In general, the rates of placental and fetal infection were the highest in the case of intravenous inoculation, the second highest in the case of intraperitoneal inoculation, and the lowest in the case of subcutaneous inoculation, although there were small differences in this tendency among the mouse strains used. The differences in the rates of placental and fetal infection were presumed to be derived not from the difference in the severity of infection of the respective mothers, but from the degree of direct approach of virus to the placenta as one of the factors.

Animals↗

Immunochemical and immunoelectron microscope studies on localization of NADPH-cytochrome c reductase on rat liver microsomes.

By the use of ferritin-conjugated antibody (conjugate) indirect immunoelectron microscopy, NADPH-cytochrome c reductase was localized on rat liver microsomes. Most microsomes in the sections had from 1 to 12 conjugates on their outer surfaces. Among the conjugates, 83% was estimated to bind to NADPH-cytochrome c reductase at a molecular ratio of 1:1, 12% at the ratio of 2:1, and 5% at the ratio of 3 or 4:1. The correlation between immunochemical and morphological data confirmed that most of the NADPH-cytochrome c reducatase reacted with the conjugates. Subsequent morphological analyses have revealed that the enzyme is distributed homogeneously on the outer surfaces of microsomes but heterogeneously within microsomes in groups of three to five enzyme molecules.

Animals↗

The linear model: a statistical tool applied to psychophysical research in dental prosthetics.

The construction of a linear model is described, and its function in analysing variations in the perception of comfortable mandibular occlusal positions is explained. In principle, the model combines analyses of variance and regression in a number of simple computer operations. Data from a clinical study were used to demonstrate the analytical capacity of a specific model, designed to estimate the effect of factors, which were supposed to influence the perception of comfortable mandibular positions.

Adult↗

Continuous monitoring of circulating blood hematocrit.

The relationship between the hematocrit value and the absolute value of impedance of whole blood was analyzed. The results indicated that the hematocrit value was linearly proportional to the logarithm of the impedance of whole blood over the range of hematocrit values of 10 to 60% with a correlation coefficient of 0.995. The circuit used for detection of the impedance of whole blood was described. It required no adjustments during measurements and had a wide linear range. The sources of error during continuous measurements were the rate of blood flow through the sensor cell, the temperature of the blood, and the concentrations of plasma proteins and ions. Accordingly, the flow and temperature of blood were kept constant during measurements. Changes in the concentrations of plasma proteins and ions within physiological ranges caused errors of +/- 2.0%. Typical results of continuous measurements were presented, showing that the hematocrit values obtained by this method agreed well with those obtained by the conventional methods from the packed cell volume. An advantage of this method over the conventional methods was that it could follow rapid and transient changes in the hematocrit.

Animals↗

Experimental studies on vertical infection of mice with Japanese encephalitis virus. I. Effect of mouse strain on placental and fetal infection.

An experiment was carried out with mice to study the effect of the mouse strain on the establishment of experimental vertical infection with Japanese encephalitis virus. Mice of various inbred strains were inoculated with a field strain of virus on the 7th day of pregnancy. An attempt was made on them to recover the virus from the placenta and fetuses. As a result, there were differences in the rate of placental and fetal infection among the mouse strains used. It was clarified that vertical infection could be established experimentally in some selected mouse strains. There was not always a parallel relationship between the rate of placental and fetal infection and the severity of viremia or visceral infection in the dam.

Animals↗

Localization of nascent NADPH-cytochrome c reductase in rat liver microsomes.

Rat liver microsomes incubated with [3H] puromycin in high salt buffer were digested with a mixture of protease, trypsin and chymotrypsin, in both the presence and absence of 1 % deoxycholate. Our observations revealed that the proteolysis of peptidyl puromycin labeled with [3H] puromycin was at least partially protected by the presence of microsomal membrane. Immuno-chemical analyses have further shown that most of the nascent NADPH-cytochrome c reductase in the microsomes was digested with the proteases while serum albumin was effectively protected from the digestion. It is thus proposed that NADPH-cytochrome c reductase synthesized on the membrane bound ribosomes is not transported to the vesicular cavity but directly to the outer surface of the microsomal membrane in a form which is accessible to the proteases.

Acyltransferases↗

The electrocardiogram of burros.

Electrocardiograms of two burros are presented. Compared to those seen in humans, amplitudes were lower, especially in lead I, and marked prolongations were observed in P-Q and Q-T intervals. The QRS axes were craniad.

Animals↗