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Biomedical subjects

R Hayashi

Publications and source records attributed to R Hayashi.

At least 199 records · Page 11Linked to original sources
PubMed1991

Disturbed modulation of the stretch reflex gain during standing in cerebellar ataxia.

The postural control disturbance in patients with spino-cerebellar degeneration (SCD) was evaluated by the displacement of the center of foot pressure (CFP) and the amplitude of the triceps surae muscle H reflex in various standing postures. Twelve patients and 8 age-matched normal subjects (NL) were studied. The CFP, surface electromyograms (EMG) in the lower leg and the soleus H reflex were recorded in all subjects. The CFP displacement area was recorded in 10 patients. The following results were obtained: (1) the range of displacement of CFP from forward to backward leaning as a fraction of foot length was significantly smaller in the patients than in the controls (mean +/- S.D.; SCD = 52.8 +/- 12.7%; NL = 62.3 +/- 9.9%; P less than 0.05%, Student's t test); (2) the ratio of the increase in amplitude of the H reflex to soleus muscle EMG activity when the subjects leaned forward from an upright posture was significantly higher in the patients than in the controls (SCD = 0.41 +/- 0.40; NL = 0.17 +/- 0.15, P less than 0.05); (3) this ratio correlated with the area of CFP displacement during upright standing in the patients (r = 0.75, n = 10, P less than 0.05). These results indicate that the suppression of the stretch reflex observed in normal controls during standing is impaired in patients with SCD. We conclude that a decreased suppression of the stretch reflex is one of the mechanisms responsible for the instability on standing in patients with SCD.

Adult↗
PubMed1991

Effects of high hydrostatic pressure on characteristics of pork slurries and inactivation of microorganisms associated with meat and meat products.

Pork slurries inoculated with various test microorganisms were prepared and subjected to high hydrostatic pressure at 1000 to 6000 atm for 10 min at 25 degrees C to examine for the pressure effects on characteristics of the slurries and the inactivation of the microorganisms associated with meat and meat products. Pressure treatment at higher than 3000 atm caused coagulation and discoloration of the pork slurries. Harder and more white coagulants were obtained by increasing the pressure. Pressure treatment at 3000 to 6000 atm killed all the microorganisms tested by more than 6-log colony-forming units (cfu)/g except Bacillus cereus spores. Gram-negative microorganisms were more labile to pressure than Gram-positive ones. Campylobacter jejuni, Pseudomonas aeruginosa, Salmonella typhimurium and Yersinia enterocolitica were inactivated at pressures higher than 3000 atm; Escherichia coli, Saccharomyces cerevisiae and Candida utilis at pressures higher than 4000 atm; Micrococcus luteus, Staphylococcus aureus and Streptococcus faecalis at 6000 atm. Only less than one-log cfu/g of B. cereus spores were inactivated at 6000 atm. Ultraviolet absorption spectra and acridine orange staining suggested that E. coli became permeable and leaked cytoplasmic RNA at lower pressure than S. aureus. From the present findings, the authors propose high hydrostatic pressure treatment as a promising means of preparing wholesome meat and meat products.

Animals↗
PubMed1991

Tension lines of the auricular cartilage.

Utilizing Langer's technique for skin tension lines, we punctured the auricular cartilage of 10 human cadavers and 2 mature rabbits and 24 immature rabbits with a conical awl to determine their tension lines. Deformation of the holes into straight lines indicated the direction of maximum tension. A regular pattern was observed in adult rabbits and humans: Tension was at right angles to the long axis at the auricular base and parallel at the apex. This pattern was not present at birth, but developed at 1 to 2 weeks of age in rabbits. It is felt that these tension lines are responsible for the clinical results of auricular reconstruction. In children less than 1 week of age, tension lines are disorganized so that nonsurgical correction will be successful as long as hypoplasia is not present. In older children, correction will be successful when the deformity is parallel to the tension lines.

Animals↗
PubMed1991

[A study on urinary tin in healthy adults: relationship between the concentration of urinary tin and life style].

The concentrations of urinary tin in healthy adults in Aichi prefecture were determined by anodic stripping voltammetry over a period of three years (1986-1988), to obtain the normal tin level in urine and to elucidate the influence of environmental alterations on health conditions in the future. In addition to the above-mentioned method, the relationship to life style, dietary habits, smoking habits and living environment were studied, and the following results were obtained. 1) The mean +/- standard deviation of urinary tin levels for males was 3.7 +/- 2.2 (micrograms/g creatinine), and 5.9 +/- 3.0 (micrograms/g creatinine) for females. The data showed logarithmic normal distributions in both sexes, and the mean concentration for females was significantly higher than that for males (P less than 0.001). The levels of urinary tin concentrations significantly increased according with age. 2) Significant correlations of urinary tin concentrations between two observations were noticed in repeated by observed subjects. 3) As to the dietary habits, fish intake increased the urinary tin concentration, but no definite association with canned-food intake was observed. 4) Smoking habits and living environment also showed a tendency to increase the urinary tin concentration, but the difference was not statistically significant.

Adult↗
PubMed1990

[An evaluation of excisional biopsy for tongue carcinoma].

An evaluation of excisional biopsy for tongue carcinoma (T1, T2) as a surgical treatment was performed. Forty-seven patients who received excisional biopsy among 394 patients with tongue carcinoma (T1, T2) treated in National Cancer Center Hospital during 24 years were examined. These patients were divided into following three groups: group a) patients treated with excisional biopsy only, group b) those treated with excisional biopsy and cryosurgery, group c) those treated with excisional biopsy and radiotherapy. We examined local control rate of these groups, degree of differentiation in histopathological examination, and median cancer free surgical margin. From these we obtained following results: 1) There was no significance in local control rate among these three groups (group a 77%, group b 84%, group c 45%) 2) There were no local recurrences in the patients with cancer free margin of 5 mm or more except when the histopathology showed perineural invasion, lymphatic vessel invasion, and/or deep invasion to the muscle. 3) Even if we had cancer positive surgical margin with excisional biopsy, we could obtain high local control rate (75%) with additional cryosurgery. We conclude that excisional biopsy for tongue carcinoma (T1, T2) is a good method for primary therapy.

Adult↗
PubMed1990

Protective efficacy of the Takeda acellular pertussis vaccine combined with diphtheria and tetanus toxoids following household exposure of Japanese children.

The clinical efficacy of an acellular pertussis vaccine containing lymphocytosis-promoting factor, filamentous hemagglutinin, agglutinogens, and the 69-kd outer membrane protein, combined with diphtheria and tetanus toxoids and adsorbed onto an aluminum salt, was assessed in a household contact study. The occurrence of pertussis 7 to 30 days following home exposure among 62 previously vaccinated children was compared with that among 62 unvaccinated children similarly exposed. Classic whooping cough was diagnosed in 43 unimmunized children, and 1 vaccinated child experienced a 5-week illness that was probably pertussis (efficacy, 98%; 95% confidence interval, 84% to 99%). A few children in each group incurred respiratory illnesses that may have represented mild, atypical pertussis; including these as probable pertussis, vaccine efficacy was 81% (95% confidence interval, 64% to 90%). It is concluded that prior immunization with this four-component pertussis vaccine combined with diphtheria and tetanus toxoids is highly efficacious in preventing pertussis.

Bias↗
PubMed1990

In vivo 31P nuclear magnetic resonance findings on heterotopically allografted hearts in rats treated with a novel immunosuppressant, FK506.

Administration of FK506 for 15 days at daily doses of 3.2 mg/kg p.o., 10 mg/kg p.o., 0.32 mg/kg i.m., or 1 mg/kg i.m. to heart-allografted rats resulted in a significant prolongation of graft survival time. The best graft acceptance was obtained in the 1 mg/kg i.m. group: all six grafts survived longer than 50 days, and two of them, indefinitely. The 31P nuclear magnetic resonance (NMR) technique was utilized to investigate in vivo the energy metabolism of grafts. The ratios of inorganic phosphate (Pi)/phosphocreatine (PCr) and PCr/ATP were useful parameters for monitoring cardiac insufficiency after transplantation. The mean ratios of Pi/PCr and PCr/ATP in syngeneic grafts were 0.38 +/- 0.11 and 1.88 +/- 0.42, respectively. In the control allografts, a rapid increase in the Pi/PCr ratio and a decrease in the PCr/ATP ratio were found from day 5. During the period of FK506 administration, increased Pi/PCr and decreased PCr/ATP ratios were also observed in all groups. The changes in these ratios were related with FK506 dosage. The results suggest that FK506 has a side-effect on graft metabolism. The metabolism tended to improve upon cessation of the drug in all grafts, but it worsened again in 3-3 1/2 weeks in the rats treated with 3.2 mg/kg p.o., 10 mg/kg p.o., or 0.32 mg/kg i.m. This seemed to be due to graft rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Platysma musculocutaneous flap for reconstruction of trachea in esophageal cancer.

In 2 patients with advanced cervical esophageal cancer invading the trachea, total laryngoesophagectomy with resection of the posterior portion of the trachea and lymph node dissection of the bilateral neck and superior mediastinum was carried out. The partial defect in the trachea was repaired with a platysma musculocutaneous flap. A permanent tracheostoma, composed of the tracheal remnant anteriorly and the platysma musculocutaneous flap posteriorly, was made just over the manubrium sterni.

Aged↗
PubMed1990

Effects of unexpected perturbations on trajectories and EMG patterns of rapid wrist flexion movements in humans.

To investigate how motor programs can be modified by sensory inputs we recorded kinematic and EMG patterns from normal human subjects performing well-practised wrist flexion movements in response to an auditory tone. On random trials unexpected wrist perturbations were introduced at varying times after the signal to move had been given. Extension perturbations delivered before agonist EMG onset resulted in an increased maximum velocity (MV) during the wrist flexion movement and in an increased target overshoot even though the wrist was further from the target than expected by the subject at the onset of the movement. The first agonist EMG burst and the antagonist burst were both increased in magnitude in these perturbed trials. Flexion perturbations delivered before the agonist EMG onset moved the hand nearer to the target just prior to movement onset. These resulted in a reduced MV, but the expected increased target overshoot did not occur. The first agonist burst was reduced in magnitude, and the antagonist burst was increased in magnitude. Perturbations delivered after agonist EMG onset produced less change in the first agonist and antagonist EMG burst, and less compensation for the perturbation was evident in wrist position and velocity recordings. These results indicate that, at least in some situations, motor programs for rapid voluntary movements can be modified by afferent inputs. This interaction between central motor commands and sensory feedback might occur at the cortical or spinal level, depending on when perturbations occur relative to onset of EMG and movement. The timing of the EMG changes suggest that both reflex mechanisms and longer latency 'voluntary' adjustments contribute to the compensatory changes in movement trajectory.

Adult↗
PubMed1990

Nonsurgical correction of congenital auricular deformities.

Congenital auricular deformities are found in 55.2 per cent of neonates at birth. When the deformities are not hypoplastic, nonsurgical correction is very easy and reliable. Lop ear and Stahl's ear respond well to the nonsurgical correction only during the neonatal period, while protruding ears and cryptotia respond until approximately 6 months of age. We noticed that there are variations in the time period for response to nonsurgical correction in the different types of auricular deformities. We have continually observed the natural changes in 1000 babies' auricular shapes from birth to 1 year of age. Lop ear and Stahl's ear were auricular deformities that appeared in 47 per cent of all newborn babies. Eighty-four per cent of these deformities disappeared spontaneously during the first year of life. They were present in 7 per cent of the 1000 babies at 1 year of age. On the other hand, the percentage of protruding ears increases from 0.4 per cent at birth to 5.5 per cent at 1 year of age. Our observations show that most of the protruding ears are acquired deformities. If a baby is placed in a supine position, the weight of the baby's head will fold the ear forward when the baby turns its head to one side; this is the mechanism presented as the probable cause for the acquired protruding ear.

Ear, External↗
PubMed1990

[Long-term results of total correction of tetralogy of Fallot less than 2 years old].

Between April 1972 and March 1979, eighteen total correction for tetralogy of Fallot less than 2 years old were performed with a mortality rate of 11.1%. The valved patch made of autologous pericardium was utilized for right ventricular outflow reconstruction in 12 of 16 survivors. Late (from 10 to 17 postoperative year) results of the all survivors were studied on functional and clinical status, hemodynamics and cardiac functions, and also, were compared with that of the patients above 2 years of age. All of them were in NYHA class I with no physical exercise limitation. Chest X-ray showed nearly normal CTR of 51.7%. ECG showed complete or incomplete RBBB in 14 patients and LAD in 3 of them, whereas no ventricular arrhythmia. Cardiac catheterization and cineangiography revealed that they had quite satisfactory hemodynamics and cardiac functions despite their moderate pulmonary regurgitation. In comparison with the older patient group, this younger one had a tendency to take superior results in all parameters of cardiac functions and clinical status. These excellent long term results seem to come from their young and less degenerative myocardium at the time of surgery.

Adolescent↗
PubMed1990

[Clinical study on the use of retrograde cardioplegia with St. Thomas' Hospital solution].

One hundred and three consecutive patients with aortic valve disease and twenty seven patients with ischemic heart disease of severe critical coronary stenosis or left main trunk stenosis underwent open heart operations with the use of retrograde cardioplegic technique for myocardial protection. Under complete cardiopulmonary bypass, a balloon catheter was inserted into the coronary sinus through small right atriotomy and secured in place. Retrograde cardioplegia was accomplished using cold St. Thomas' Hospital solution by drip method at height of 60 to 80 cm with topical saline slush. Cardiac resuscitation was very easy and acceptable hemodynamics were obtained in all patients. Even in 8 patients in which aortic crossclamping time was above 180 minutes cardiac recovery was excellent except one who needed IABP support. Eight patients in aortotomy group were died postoperatively from the reasons unrelated to myocardial protection. Postoperative hemodynamic data and enzymatic analyses of CK-MB revealed good myocardial protective effects. Retrograde cardioplegia with the use of cold St. Thomas' Hospital solution is thus an effective alternative of myocardial protection in aortic valve surgery or aortotomy surgery and in coronary revascularization for multiple coronary stenoses or left main trunk lesions.

Adult↗