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Biomedical subjects

T Kasai

Publications and source records attributed to T Kasai.

At least 235 records · Page 13Linked to original sources
PubMed1992

A simple method for determining critical speed as swimming fatigue threshold in competitive swimming.

The purpose of this investigation was to determine whether the concept of the critical power could be applied to competitive swimming by using critical swimming speed (CS) as determined both in the swimming flume (CS-flume) and in the normal swimming pool (CS-pool) and whether CS could be utilized as a practical index for assessing a swimmer's endurance performance. CS defined as the swimming speed which could be theoretically maintained continuously without exhaustion was expressed as the slope of a regression line between swimming distance (D) and its duration (T) obtained at various swimming speeds. Eight highly trained swimmers were instructed to swim until onset of fatigue at four predetermined swimming speed levels in the swimming flume and at maximal effort over four different swimming distances in the swimming pool. In the results of CS-flume and CS-pool, the regression relations between D and T were expressed in the general form, D = a+b x T, with r2 being higher than 0.998 (p less than 0.01), respectively. These results both from the flume and the pool indicated extremely good linearity. Furthermore, maximal oxygen uptake (VO2max) during the incremental exercise test, swimming speed corresponding 4 mM of blood lactate concentration (V-OBLA) and mean velocity in the 400 m freestyle (V-400) were measured on each subject.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Effects of varying load conditions on the organization of postural adjustments during voluntary arm flexion.

One purpose of the experiments reported here was to further clarify the effect of varying loads on postural adjustments. Another was to reevaluate whether or not the timing of electromyographic (EMG) activity in the postural muscle is preprogrammed. To accomplish these goals, we compared the effect of the presence or absence of prior knowledge of a load on the timing of EMG activity in the postural muscle (biceps femoris [BF]) with that in the focal muscle (anterior deltoid [AD]). Although the sequence of EMG activation was similar under conditions with and without a load, the timing of postural EMG activities (BFi, ipsilateral BF; BFc, contralateral BF) in associated postural adjustments was dependent on the force of arm movement, and the latencies of postural EMG activities (BFi-BFc) were dependent on the speed of arm movement. This indicates that EMG changes in the upper (focal muscle) and lower limbs (postural muscle) were triggered by different motor programs. Moreover, similar EMG activities were observed in postural muscles when the subject had advance knowledge of the presence or the absence of a load. Thus, this suggests that BFi may be centrally preprogrammed (anticipatory regulation) and BFc may be feedback regulated. Furthermore, environmental information may be a critical source of influence on those postural responses.

Journal Article↗
PubMed1992

Comparative effects of dopamine and dobutamine on the pulmonary haemodynamic response to hypoxia in dogs ventilated with a hypoxic gas mixture.

1. The effects of dopamine and dobutamine on the pulmonary haemodynamic response to hypoxia were studied in nine anaesthetized dogs under hypoxaemia induced by ventilation with hypoxic gas mixture. 2. From the present study, only dopamine infusion reduced arterial oxygenation during hypoxic hypoxaemia, whereas catecholamine maintained it at the same level during normoxaemia. 3. A redistribution of perfusion to the pulmonary vasculature may be related to a reduction of arterial oxygenation with dopamine infusion during hypoxic hypoxaemia. 4. It is presumed that an increase in pulmonary blood flow would emphasize an inhibition of hypoxic pressor response in the pulmonary vasculature, which may not be a direct effect of dopamine.

Animals↗
PubMed1992

Surfactant replacement therapy in premature babies with respiratory distress syndrome: factors affecting the response to surfactant and comparison of outcome from 1982-86 and 1987-91.

The impact of surfactant therapy on chronic lung disease remains uncertain. During the past decade (1982-91), over 300 babies with respiratory distress syndrome (RDS) weighing 501-2,500 g at birth were consecutively treated with surfactant-TA at our neonatal intensive care unit. Data on 95 RDS babies treated in the first 5 year period (Period 1, 1982-86) were compared with those on 158 RDS babies treated in the second 5 year period (Period 2, 1987-91). Overall respiratory improvement was better in Period 2 than in Period 1. In Period 2, surfactant therapy converted 98% of the babies with moderate/severe RDS to those with 'near normal' lung by 72 hr post-treatment. In Period 2, 95% of the surfactant-treated babies weighing 501-1,750 g at birth survived, 97% of which required no supplemental oxygen at 40 weeks corrected gestational age. Increased survival rate in the surfactant-treated babies during the past decade has not been followed by a parallel increase in chronic lung disease. The severity of the initial pulmonary disease per se was not the significant risk factor for chronic lung disease. Several other variables affecting the response to surfactant therapy and outcome have been identified by stepwise logistic regression analysis and include factors related to perinatal events such as birth asphyxia and infection, and other complications of prematurity.

Chronic Disease↗
PubMed1992

Clinical course of early fetal loss and its chromosomal characteristics.

The relationship between types of chromosomal abnormalities and fetal development documented by ultrasonography was discussed in early spontaneous abortions. The subjects were 113 patients who had vaginal ultrasonography at least twice between 6 and 8 weeks of pregnancy, among 167 abortuses with chromosome analyzed. The results were also compared against those for 303 normally developing fetuses. The results obtained in the present study suggested that each fetus with a chromosomal abnormality succumbed at or after a specific stage of fetal development and that the fetal death might be the results of severe fetal growth suppression.

Abortion, Spontaneous↗
PubMed1992

Validity of critical velocity as swimming fatigue threshold in the competitive swimmer.

The purpose of this investigation was to determine whether the critical velocity (CV) as the swimming speed which can be theoretically maintained for a very long time without exhaustion could be applied to estimate the swimmer's endurance performance. CV was based on the concept of critical power originality established by Monod and Scherrer (1965) and extended by Moritani et al. (1981), and expressed as the slope of a regression line between swimming distance (D) at each velocity and its sustained time (T). Seventeen highly trained swimmers were instructed to swim the four different swimming distances (50 m, 100 m, 200 m and 400 m) at maximal effort using the swimming pool. In the results of CV, the regression relations between D and T were expressed in the general form, D = a + bxT, with r2 showing higher than 0.997 (p less than 0.001). These results indicate extremely good lineality. Furthermore, VO2max during incremental exercise test, swimming speed corresponding 4 mM of blood lactate concentration (V-OBLA) and mean velocity in the 200 m and 400 m freestyle (V-200 and V-400) were measured on nine subjects. Significant correlations were found between CV and V-OBLA (r = 0.862, p less than 0.01), CV and V-200 (r = 0.781, p less than 0.01), CV and V-400 (r = 0.999, p less than 0.001), V-OBLA and V-400 (r = 0.869, p less than 0.01) and V-200 and V-400 (r = 0.776, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Competitive Behavior↗
PubMed1992

Accumulation of hypotaurine in tissues and urine of rats fed an excess methionine diet.

Hypotaurine increased in some tissues, especially in muscle, and urine of rats fed methionine excess diet. The significant depression of the body weight and food intake of rats caused by excess methionine was remarkably alleviated as previous reports and hypotaurine content in muscle and urine increased further by supplement with glycine to the excess methionine diet.

Animals↗
PubMed1992

[Clinical course of asthmatics with severe asthma attack].

This study was conducted on 39 patients whose severe attacks of bronchial asthma with disturbance of consciousness required admission to the ICU of our hospital between 1984 and 1989. Among the 39 patients, there were 16 deaths. Most patients collapsed suddenly at home and were taken to our hospital. Arterial blood gas analysis at the time of admission to the ICU revealed that the PaO2 levels were as high as 252.6 +/- 57.6 (mean +/- S.E.) Torr in non-survivors and 221.0 +/- 29.7 Torr in survivors, with no significant difference because of prior oxygen therapy in almost all cases. Systolic blood pressure was 14.8 +/- 10.8 (mean +/- S.E.) mmHg, with marked circulatory disturbance in the fatal cases. Most patients displayed marked disturbance of consciousness, but maintenance of blood pressure led to recovery without sequelae despite marked disturbance of consciousness in most patients.

Adolescent↗
PubMed1991

Basaloid carcinoma of salivary glands, a variety of undifferentiated adenocarcinoma. Immunohistochemical study of intermediate filament proteins in 24 cases.

Among adenoid cystic carcinomas of salivary glands (ACCs), the solid basaloid type has a poor prognosis similar to that of undifferentiated adenocarcinomas. We studied 24 cases in immunohistochemistry using antibodies reactive with keratins of various molecular weights, vimentin, S-100 protein, and its A and B subunits. Our findings were correlated with the histological pattern and with the variable degree of differentiation of these carcinomas. In comparison with other types of ACC, intermediate filament proteins in this group were weakly expressed. The co-expression of cytokeratin and vimentin was noted in some cases. Additional features noted were the presence of cribriform cavities associated with solid lobules and areas of necrosis giving a comedocarcinomatous pattern. In these two variants, cells characterized by the dual expression of cytokeratin and S-100 protein were seen. In the highly malignant anaplastic variety, only a few cells were weakly positive with antisera to cytokeratin and vimentin. This group shows similarities to undifferentiated adenocarcinomas of salivary glands. Such similarities could be explained by the common origin of these tumours from intercalated ducts.

Carcinoma, Transitional Cell↗
PubMed1991

Immunohistochemical expression of amelogenins in odontogenic epithelial tumours and cysts.

Amelogenins, enamel proteins in odontogenic tumours, were detected immunohistochemically using a monoclonal antibody. They were strongly expressed in amyloid-like material, ghost cells, and the cells surrounding ghost cells of calcifying epithelial odontogenic tumours and cysts, whereas calcified bodies within the tumours and cysts showed negative staining. The expression of amelogenins was also positive in tumour cells of ameloblastoma, adenomatoid odontogenic tumour, squamous odontogenic tumour and ameloblastic fibroma. Peripheral tumour cells of the follicular ameloblastoma were positive with relatively intense staining. Undifferentiated or flattened tumour cells of adenomatoid odontogenic tumour and non-keratinized tumour cells of the squamous odontogenic tumour showed marked staining. Reduced ameloblasts in the odontoma displayed the strongest staining for amelogenins. The study suggests that biosynthesis of amelogenins may occur in the homogeneous materials of calcifying epithelial odontogenic tumours and cysts.

Ameloblastoma↗
PubMed1991

Antagonist inhibition during rest and precontraction.

The excitability of antagonist soleus motoneurons was tested during fast voluntary contractions of tibialis anterior (TA). Contractions of TA started either from zero or higher levels of tonic contraction of ankle extensors. Results showed that H reflex depression under 3 different conditions: 25% (R25) or 50% (R50) of the maximal isometric dorsiflexion from the resting state and the sequential isometric response (SW) appeared about 20-40 msec prior to the EMG onset of TA. In particular, H reflex depression was clear in the SW response, and the stronger the prior contraction of extensors the greater the H reflex depression. There was a significant difference in the integrated EMG between R25 and SW but none between R50 and SW. The different amounts of inhibition found for dorsiflexion from the resting state and sequential movement is most probably explained by presynaptic inhibition. If presynaptic inhibition were increased throughout the sequential movement, in comparison with the resting state, change in the H reflex gain would occur.

Adult↗
PubMed1991

Rupture of the heart in a burn patient: a case report of free wall rupture of the left ventricle.

A 63-year-old male was burned when in a state of alcoholic intoxication, he fell head first into a bathtub filled with hot water and received burns covering 40 per cent BSA. Despite surgical wound debridement, a severe sepsis continued and a sudden cardiac arrest occurred. Autopsy revealed a large volume of blood in the pericardial space. The heart was ruptured through a myocardial abscess in the posterior wall of the left ventricle. The principle cause of his death was attributed to acute cardiac tamponade following cardiac rupture through a myocardial abscess.

Abscess↗
PubMed1991

An immunohistochemical study of the distribution of lysozyme, lactoferrin, alpha 1-antitrypsin and alpha 1-antichymotrypsin in salivary adenoid cystic carcinoma.

The immunohistochemical expression of lysozyme (Ly), lactoferrin (La), alpha 1-antitrypsin (alpha 1-AT), and alpha 1-antichymotrypsin (alpha 1-Ach) was described, and their distributions were compared to each other in 28 cases of adenoid cystic carcinoma (ACC) of the salivary glands. ACC materials were obtained from the parotid gland (7), the submandibular gland (4), the sublingual gland (8), and minor oral salivary glands (9). Histopathologically, ACC was classified into cribriform (14), tubular (3), and basaloid or solid patterns (11). Positive staining for Ly was found in 1 case of solid ACC in the sublingual gland; La was found in 4 cases (2 cribriform, 1 tubular, 1 basaloid) in the sublinguals (3) and parotid glands (1); alpha 1-AT was found in 6 cases and alpha 1-Ach in 17 cases. The immunohistochemical localization of Ly and La was usually confined to luminal tumor cells of tubulo-ductal structures, irrespective of the pathologic types. Positive staining for alpha 1-AT and alpha 1-Ach appeared in tumor cells of cribriform, tubular and solid ACC. Tumor cells with positive La staining coincided with a positive reaction to alpha 1-AT and alpha 1-Ach, and tumor cells with alpha 1-AT positive deposition were also positive for alpha 1-Ach. The contents of pseudocysts in the cribriform pattern showed a positive reaction to La, alpha 1-AT, and alpha 1-Ach. Of the 28 cases of ACC, positive expressions for Ly, La, alpha 1-AT and alpha 1-Ach were found with a high frequency of alpha 1-Ach staining (17 in 28 cases were positive). In sublingual ACC (8), 7 cases were positive for immunohistochemical reactions. Co-expression or simultaneous expression for Ly, La, alpha 1-AT, and alpha 1-Ach in ACC suggest that tumor cells are protected from proteolysis or degradation.

Carcinoma, Adenoid Cystic↗
PubMed1991

An empirical note on tonic neck reflexes: control of the upper limb's proprioceptive sensation.

The effect of asymmetrical tonic reflexes on the upper limb in man was studied by analyzing errors in reproducing a targeted movement in right elbow extension following head rotation and vibration of the neck muscles. Overshoot of reproduction was observed only when the head was rotated to the left in contrast to no rotation or with rotation to the right. However, there was no influence on errors of reproduction after vibration of the neck muscles. These observations suggest that the proprioception in the rotated head controls the kinesthetic input by peripheral sensory receptors, namely, vestibular input plays a greater role in the accurate positioning of the upper limb, especially in inhibiting sensory input from the opposite side of the rotated head.

Adult↗
PubMed1991

A tongue-like projection of the left lobe in human liver, accompanied with lienorenal venous shunt and intrahepatic arterial anastomosis.

The characteristic features of a tongue-like projection of the left lobe of the liver in a female adult, accompanied with a large lienorenal venous shunt and an intrahepatic anastomosis of the hepatic arteries, are described. By dissecting the liver parenchyma, this projection is supplied by a set of the lateral segmental branches of the portal vein, hepatic artery and hepatic ducts and by the branch of the left hepatic vein. The boundary between the abnormal and the proper left lobes can not be confirmed accurately, because the tongue-like projection is overlapped with the paraumbilical lobe on the visceral surface. However, the position is estimated a transverse line superior to the attachment to the proper left lobe. The anomaly is derived from a medial and inferior portion of the left lobe of the liver and may be regarded as a left half of the central lobe in the ape etiologically. No evidences to justify the co-existence of the tongue-like projection with the lienorenal shunt are confirmed.

Aged↗
PubMed1991

Heterogeneity and co-expression of intermediate filament proteins in adenoid cystic carcinoma of salivary glands.

Among a series of 76 adenoid cystic carcinomas (ACC), 51 cases with cibriform or trabecular patterns were selected for an immunohistochemical study. These tumors were composed of three types of cells: basaloid, myoepithelial and ductal luminal acinous or tubular cells with a variable amount of each cell type from one case to another. Monoclonal antibodies (MoAb) against keratins (PKK1, KL1, K8.12, K8.13, K4.62 anti-cytokeratins antibodies) and against vimentin were used. Tubular cells were characteristically marked by anti-cytokeratins MoAb, but with a great heterogeneity of keratin distribution. In myoepithelial cells, keratin was absent or slightly positive and vimentin was present, with co-expression of the two types of filaments in some cells. Like myoepithelial cells, basaloid cells were positive to anti-vimentin antibody and negative or slightly positive to anti-keratin antibodies, with sometimes a co-expression of vimentin and keratin filaments in the same cell. Histogenesis of adenoid cystic carcinomas was discussed. Progenitor intercalated duct reserve cells may change into ductal luminal and myoepithelial tumor cells. Otherwise, basaloid cells, arising also from intercalated duct reserve cells, are able to acquire some secretory organites.

Antibodies, Monoclonal↗
PubMed1991

Reinforcement of motor evoked potentials in patients with spinal cord injury.

Transcranial magnetic stimulation of the motor cortex has been used to investigate the putative existence of spared motor pathways in spinal cord injured patients with clinically complete paralysis. Particular consideration was given to methods of neurological reinforcement likely to minimize the risk of false negative interpretation of absent motor evoked potentials (MEPs). The principal methods of reinforcement included target and remote muscle contractions and conditioning of MEPs with a brief (20 msec) train of cutaneous stimulation (500 Hz: duration 0.1 msec) delivered 20-150 msec prior to cortical stimulation. Twelve control subjects and 26 patients with severe traumatic spinal cord injury underwent cortical stimulation delivered from a Cadwell MES-10 (70-100% intensity) through a 9-cm focal-point coil. Electromyographic responses were recorded from surface electrodes in bipolar configuration and amplified (3 dB down at 10 Hz-1 kHz) prior to storage. MEPs were recorded, following reinforcement, in muscles with clinically complete paralysis in 4/26 patients. In each case, MEPs were of low amplitude (less than 0.5 mV), polyphasic, and with variable and prolonged latencies. MEPs were evoked in severely paretic (clinically incomplete paralysis) muscles in 6/8 patients only when neurological reinforcement was employed. Conditioning of MEPs in tibialis anterior with preceding cutaneous stimulation to the plantar surface (subthreshold for evoking a flexion reflex) yielded a well-defined modulation of MEP amplitude in control subjects. An early (Conditioning-Test (C-T) intervals 20-45 msec) period of inhibition of MEPs (mean = 60% of control) was followed by a period (C-T intervals 50-90 msec) of facilitation (mean = 345%) and a subsequent (C-T intervals 90-150 msec) period of inhibition (mean = 0%). In spinal cord injured patients the same conditioning paradigm failed to reveal MEPs, but did result in the appearance of suprathreshold flexion reflexes in 2 patients at 20-55 msec C-T intervals. This summation of convergent but subliminal cortical and cutaneous inputs to the target motoneuron pool provided additional evidence of preserved cortical influence on segmental structures that was not detectable by other means. These results extend previous reports of electrophysiological evidence of spared motor pathways in spinal cord injured patients with complete paralysis, and affirm the need for neurological reinforcement as a routine procedure in cortical stimulation studies of spinal cord injuries.

Adult↗