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Biomedical subjects

Y Mutoh

Publications and source records attributed to Y Mutoh.

At least 19 recordsLinked to original sources
PubMed2002

Characteristics of stress fractures in young athletes under 20 years.

BACKGROUND: With the popularization of organized sports among adolescents and children, the clinical cases of stress fractures in young athletes have increased. This study was carried out to investigate the characteristics of stress fractures in young athletes. METHODS: During the 18-month period between January 1996 and June 1997, new clinical cases of stress fracture due to sports activities were collected from 39 hospitals in Japan. RESULTS: We analyzed 222 stress fractures in 208 athletes under 20 years of age (108 males: 14.4+/-2.2 years, 100 females: 15.2+/-1.5 years). Among these cases, the peak age of occurrence was 16. The most common sport causing stress fracture was basketball. The tibia was the most common location. About 70% of the patients participated in the respective sport for 6 or 7 days per week. High school students trained significantly more often than the primary and junior high school students (p<0.0001). There was a statistically significant difference in the return time to the sport between the cases who visited a hospital within 3 weeks and those who waited for more than 3 weeks after the onset of symptoms (return time, 10.4 vs 18.4 wks). Several cases visited a hospital beyond 8 weeks after the onset of symptoms regardless of the continuous pain of stress fracture, and their recovery was prolonged. CONCLUSIONS: It is important to educate young athletes that continuous pain lasting over 3 weeks is a warning signal to the body, and that early diagnosis leads to early recovery.

Adolescent↗
PubMed2001

MeOTf-mediated alkynylation of selenoamides leading to beta-methylselenenyl alpha,beta-unsaturated ketones and their characterization.

[reaction: see text] beta-Methylselenenyl alpha,beta-unsaturated ketones were effectively synthesized by treating selenoamides with methyl triflate, followed by reaction with lithium acetylides. The reaction proceeded with high stereoselectivity to give exclusively Z-isomers. (77)Se NMR studies and X-ray molecular structure analysis of beta-methylselenenyl alpha,beta-unsaturated ketones suggested that the products show 1,5-nonbonding interaction between the selenium atom and carbonyl oxygen atom.

Journal Article↗
PubMed2001

[Evaluation of coronary heart disease risk model by carotid ultrasonography in the occupational setting--intima-media thickness and coronary heart disease risk].

Recently, because of an increase in aged workers with high risk health conditions in Japan, it is becoming necessary to have a preventive control system for work-related diseases, such as coronary heart disease. We have already built a system by applying the prediction model of Framingham's risk equation for management after an annual check-up since 1999. At that time, we considered the relationship between CHD risk and intimamedia thickness (IMT) as an index of actual atherosclerosis. Correlation coefficients among max IMT, CHD risk and the several health factors in the corporate annual health check-up were obtained by Spearman's method. Significant associations with max IMT were only for CHD risk and systolic blood pressure. Correlation coefficients were 0.30 and 0.21 for CHD risk and systolic blood pressure, respectively. Furthermore, when we divided findings into those for the atherosclerotic and non-atherosclerotic groups defined by a max IMT over 1.1 mm or less, the difference between the two groups in CHD risks was investigated by t-test. The CHD risk for the atherosclerotic group was revealed to be significantly higher than that for the non-atherosclerotic group, with the means +/- SD in the two groups being 21.4 +/- 9.4% and 17.0 +/- 7.7%, respectively. CHD risk was therefore concluded to be important for the objective index of atherosclerosis from the viewpoint of high-risk-strategy in the worksite.

Adult↗
PubMed2000

Hair-discoloration of Japanese elite swimmers.

To understand hair-discoloration in relation to swimming, we examined sixty-seven elite swimmers of the Japan National Swimming Team and fifty-four, age-matched subjects as controls. The incidence of hair discoloration (61%) in the swimmers' group was significantly higher than that in controls (0%) (p<0.0001). Interestingly, surface damage of the nail plates coexisted in the swimmers with the scalp-hair discoloration. The hairs picked from the eight swimmers and two age-matched individuals as controls were examined by electron microscope (EM) and EM X-ray microanalyzer. The swimmers' discolored, golden hair revealed complete disappearance of hair cuticle both by scanning EM (SEM) and transmission EM (TEM). The quantity of melanosomes in the cortex decreased, and their diameter was smaller than that of controls. In addition, irregularly shaped melanosomes with variable electron density and less electron-dense melanosomes with white haloes were frequently observed in the swimmers' golden hair. The X-ray elemental spectrograph by SEM revealed that the content of sulfur in all the swimmers' discoloured hair was lower than that in the normal controls and that the content of chlorine in the male swimmers' discoloured hair was higher than that in the female swimmers and the normal controls. The X-ray elemental microanalysis by TEM focused on melanosomes in the cortex of the cross section and detected elemental chlorine in all swimmers' golden hairs. It did not detect any element in the control hairs. The 14C-tyrosine uptake test of hairbulbs found no significant difference between the swimmers and the normal controls. These findings suggest that hair discoloration was mainly due to cuticle damage by friction with water. Hypochlorous acid in the swimming pool water can penetrate to the hair cortex through the cuticle. It can oxidize and degenerate melanosomes there.

Adolescent↗
PubMed2000

[Ability to avoid falls among aged residents in a barrier-free welfare institution].

This study was carried out to investigate the physical functions of the elderly, living in a barrier-free home for the aged and to obtain basic data for giving appropriate guidance on exercise and daily life. A total of 38 women were tested. These included 18 persons (aged 72-87: mean: 80.7) who were living in the home for the aged, and 20 (aged 75-86: mean: 78.3) who voluntarily participated in the "fall prevention school", established in Tokyo Kosei-Nenkin Hospital. The following examinations were done: 1) BMI, Waist/Hip ratio; 2) good walker's index consisting of 10 m walking times, maximum length of steps, and 40 cm-staircase climbing; and 3) equilibrium examination done by gravinography. Statistical analysis was carried out using a paired t-test (p < 0.01). Values for the "good-walker's index" were significantly lower in, the "home" group than in the "school" group (p < 0.01). This was especially obvious with 40 cm-staircase climbing. Many of the subjects from the institution group required assistance and there was a significant difference in the chi-squire square distribution between the two groups. Furthermore, on gravinography, the "home" group had significantly inferior values in total length (cm) and Romberg's ratio (p < 0.01). It was clear that residents in the barrier-free home had a significant reduction in good-walker's index, indicating an apparent weakening of physical function.

Accidental Falls↗
PubMed2000

[Stress fracture].

Explore the source record for details and available documents.

Arthritis, Rheumatoid↗
PubMed1999

Efficacy of aquatic exercises for patients with low-back pain.

We have studied 35 patients (25 female and 10 male) with low-back pain who were managed with aquatic exercises after an appropriate period of treatment for their condition in the medical institution. The exercises employed consisted of strengthening exercises for the abdominal, gluteal, and leg muscles, stretching of the back, hip, hamstrings, and calf muscles, walking in water, and swimming. All the patients had been participating in the exercise program for more than 6 months. The frequency of performing exercises was once a week for 7 patients, twice a week for 19, and 3 or more times a week for the remaining patients. The method used in this study was a survey questionnaire which was composed of questions about the patient's physical and psychological condition. Those patients who had performed exercises twice or more in a week showed a more significant improvement in the physical score than those who performed exercises only once a week. More than 90% of the patients felt they had improved after 6 months of participation in the program. The improvement in physical score was independent of the initial ability in swimming. The results obtained suggested that exercises in water may be one of the most useful modes of exercise for a patient with low-back pain.

Adult↗
PubMed1999

[A case of carcinoma of lower lip showing excellent response to chemotherapy with UFT].

We report a case of squamous cell carcinoma of the lower lip showing an excellent response to chemotherapy with UFT. A 68-year-old woman with a painless swelling of her lower lip was refereed to our service. This tumor was 19 x 18 mm with cauliflower surface, and induration was noted around the mass. The pathological diagnosis was squamous cell carcinoma of well-differentiated type. After chemotherapy with UFT (400 mg/day), the tumor became flat. It was then removed with a 7 mm-safety margin and the lower lip was reconstructed with an Abbe-Estlandar flap from the upper lip. Post-operative histological findings indicated a complete response. Wound healing was uneventful, and there has been no evidence of recurrence for these 6 months after the operation. This case is still under observation.

Aged↗
PubMed1998

Prolonged use of intradialysis parenteral nutrition in elderly malnourished chronic haemodialysis patients.

BACKGROUND: The treatment of malnutrition, frequently present in elderly dialysis patients, is important to promote better quality of life and rehabilitation. The aim of this study was to assess the impact of prolonged use of intradialysis parenteral nutrition (IDPN) as a strategy for malnutrition in elderly haemodialysis patients. METHODS: Twenty-eight elderly patients (non-diabetic, age over 70) on chronic haemodialysis for at least 2 years were evaluated. Ten consenting patients were treated with IDPN containing glucose, essential amino acids, and lipid emulsion during the course of regularly scheduled dialysis treatments for approximately 1 year. Nutritional evaluation using seven parameters (anthropometric measurements such as body mass index, triceps skinfold thickness, mid-arm circumference, mid-arm muscle circumference, and albumin, transferrin, and total lymphocyte count) was performed at various intervals on patients with IDPN and 18 patients without IDPN. The plasma amino-acid profile and dietary protein calorie intake were also determined. RESULTS: In patients receiving IDPN, significant increases in serum albumin and transferrin concentrations and total lymphocyte count in peripheral blood smears paralleled increases in protein-calorie intake beginning after 3 months of treatment and remained favourable throughout the study period. Anthropometric data started to improve significantly after 6 months of treatment. Patients without IDPN had gradual decreases in all parameters during the study period. A significant increase in essential amino acids and a significant decrease in 3-methyl-histidine were observed in patients with IDPN and a further decrease in essential amino acids was observed in patients without IDPN. CONCLUSION: Prolonged use of IDPN prevents muscle protein catabolism and promotes body protein and fat accumulation. IDPN appears to be effective in malnourished elderly haemodialysis patients.

Aged↗
PubMed1997

Recovery of pancreatic beta-cell function in hemochromatosis: combined treatment with recombinant human erythropoietin and phlebotomy.

A patient with diabetes mellitus caused by secondary hemochromatosis was treated using recombinant human erythropoietin and phlebotomy. A total of 12 g of iron had been infused in the patient because of iron deficiency anemia. Blood glucose level was 17.3 mmol/L, and hemoglobin A1c level was 9.0% at admission. He was treated using phlebotomy (400 mL per week), along with subcutaneous injection of 3,000 U of recombinant human erythropoietin three times a week. After approximately 100 days, a total of 5,500 mL of blood (2.75 g iron) could be removed. Serum ferritin level decreased from 10,000 micrograms/L to 4,807 micrograms/L. Fasting and maximum serum C-peptide immunoreactivity values during 100-g oral glucose tolerance tests were improved from 0.14 nmol/L to 0.42 nmol/L and from 1.84 nmol/L to 2.61 nmol/L, respectively. This case suggests that pancreatic beta-cell recovers in diabetes caused by hemochromatosis by reducing iron overload during a short period.

Aged↗
PubMed1996

Adrenomedullin-sensitive receptors are preferentially expressed in cultured rat mesangial cells.

By using cultured rat mesangial cells, we compared the effects on cyclic nucleotide levels of adrenomedullin with those of the structurally related peptides, calcitonin gene-related peptide (CGRP) and amylin. Adrenomedullin potently increased cAMP levels 7-fold in a time- and concentration-dependent manner. Its EC50 was 3 x 10(-9) M. CGRP was less potent (2-fold) with an EC50 of 10(-7) M, and amylin had no effect on cAMP levels. All three peptides failed to increase cGMP levels. Treatment of cells with near maximal concentrations of adrenomedullin (10(-7) M) and CGRP (10(-6) M) had no additive effect on cAMP levels. Human adrenomedullin-(22-52)-NH2, a putative adrenomedullin receptor antagonist, inhibited the production of cAMP elicited by adrenomedullin (IC50: 7 x 10(-8) M) and CGRP (IC50: 5 x 10(-8) M). Human CGRP-(8-37), a CGRP receptor antagonist, conversely, reduced the cAMP elevation caused by these peptides with a lower potency (IC50: 10(-6) M for both peptides). This demonstrated that human adrenomedullin-(22-52)-NH2 was a more effective antagonist for adrenomedullin- and CGRP-specific receptors than human CGRP-(8-37). Results suggest that receptors sensitive to adrenomedullin are preferentially expressed in cultured rat mesangial cells. Immunohistochemical study showed almost no immunoreactive adrenomedullin and CGRP, if any, in the cells. Adrenomedullin may regulate mesangial function as either a paracrine or circulating hormone via a cAMP- but not a cGMP-dependent mechanism.

Adrenomedullin↗
PubMed1995

Adrenomedullin increases cyclic AMP more potently than CGRP and amylin in rat renal tubular basolateral membranes.

In rat renal tubular basolateral membranes, the potency to increase cAMP of adrenomedullin (AM), a novel vasorelaxant peptide originally isolated from human pheochromocytoma, was compared with those of calcitonin gene-related peptide (CGRP) and amylin. Although all three peptides raised cAMP in a time- and concentration-dependent manner with a 4-fold increase at 10(-6)-10(-5) M, the EC50 value (10(-9) M) of AM was 100-fold smaller than those of CGRP and amylin. CGRP[8-37], an antagonist for CGRP receptors, attenuated cAMP elevation induced by these peptides with the essentially similar concentration-inhibition curves. These results suggest that the receptors for AM, CGRP and amylin share a common structural homology, and that the receptors sensitive to AM are preferentially expressed in renal tubular basolateral membranes.

Adrenomedullin↗
PubMed1995

Loop diuretics act directly on adenylate cyclase in rat renal tubular basolateral membranes.

We have reported previously that loop diuretics, especially azosemide and ethacrynic acid, may act not only on the AVP receptor site, but also on the post-AVP receptor site in rat renal tubular basolateral membranes. The purpose of this study was to examine whether loop diuretics (furosemide, azosemide, ethacrynic acid) affect the post-AVP receptor components, using GTP-gamma S, forskolin and cholera toxin as tools acting distal to the receptor. Adenylate cyclase activity stimulated by 10(-9)M AVP was inhibited more potently by azosemide and ethacrynic acid than by furosemide at the concentration of 10(-3) M. Azosemide and ethacrynic acid at concentrations above 10(-4) M also significantly decreased the enzyme activity that was stimulated by 10(-7) M GTP-gamma S and 10(-5)M forskolin, while significant inhibition by furosemide was observed only at 10(-3)M. In addition, the inhibitory effect of these loop diuretics on cholera toxin-stimulated enzyme activity was almost similar to the results observed in AVP-, GTP-gamma S- or forskolin-stimulated the enzyme activity. From these results, we conclude that loop diuretics, especially azosemide and ethacrynic acid, directly affect adenylate cyclase in part as well as the AVP receptor site.

Adenylyl Cyclases↗
PubMed1994

The functional roles of disulfide bonds in the beta-subunit of (Na,K)ATPase as studied by site-directed mutagenesis.

The beta-subunit of Torpedo californica (Na,K)ATPase contains seven cysteine residues; one (Cys46) is in the single transmembrane segment and the other six (Cys127, Cys150, Cys160, Cys176, Cys215 and Cys278) are in the extracellular domain and form three highly conserved disulfide bonds. A beta-subunit mutant with replacement of Cys46 by Ser could assemble with the alpha-subunit, and the resulting alpha beta-complex was catalytically active. Mutants in which either the N-terminal side or both Cys residues of the Cys127-Cys150 bond were replaced by Ser could also tightly assemble with the alpha-subunit, but the resulting alpha beta-complex was catalytically inactive. On the other hand, disruption of either the Cys160-Cys176 or Cys215-Cys278 bond by substituting the N-terminal side only or both Cys residues with Ser led to a beta-subunit that could not assemble with the alpha-subunit. We conclude that the structure of the beta-subunit around the Cys160-Cys176 and Cys215-Cys278 loops is indispensable for assembly with the alpha-subunit, whereas the Cys127-Cys150 loop is not essential for assembly but is required for enzyme activity.

Amino Acid Sequence↗
PubMed1993

Glucose ingestion before and during exercise does not enhance performance of daily repeated endurance exercise.

The effect of glucose (Glc) ingestion before and during daily, repeated, prolonged exercise on metabolism and performance was tested. Seven young, healthy males performed cycling exercise in two series, with 1 month interval. Each exercise series consisted of 1 h/day on 3 successive days. On the 3rd day, exercise was continued until exhaustion. The intensity was 73.4 (7.7)% [mean (SD)] of maximal oxygen uptake (VO2max). Glucose (Glc) or placebo (P) drink was ingested 15 min before the start, and at 15 and 45 min of each daily exercise. The total amount of Glc ingested was 43.1 (4.2) g. During exercise, blood Glc concentrations were significantly higher (P < 0.05) when Glc was ingested than when P was ingested [Glc 5.14 (0.32) and P 4.12 (4.17) mmol.l-1 at exhaustion]. However, Glc ingestion did not improve performance time to exhaustion [Glc 92.05 (29.55) and P 98.07 (27.33) min]. Free fatty acid concentrations were significantly lower when Glc was ingested than when P was ingested [Glc 0.63 (0.21) and P 1.39 (0.46) mmol.l-1 at exhaustion]. There were no significant differences in exercise heart rate, VO2, respiratory exchange ratio, blood lactate concentrations or rating of perceived exertion between the conditions nor were there any significant differences in these parameters on different days of exercise. It seems that ingestion of small amounts of Glc does not increase the metabolism of carbohydrate or improve the performance of intensive endurance exercise of poorly trained subjects, even when the exercise is repeated daily.

Adult↗
PubMed1993

Does critical swimming velocity represent exercise intensity at maximal lactate steady state?

The purpose of this investigation was to determine whether the critical swimming velocity (vcrit), which is employed in competitive swimming, corresponds to the exercise intensity at maximal lactate steady state. vcrit is defined as the swimming velocity which could theoretically be maintained forever without exhaustion and expression as the slope of a regression line between swimming distances covered and the corresponding times. A total of eight swimmers were instructed to swim two different distances (200 m and 400 m) at maximal effort and the time taken to swim each distance was measured. In the present study, vcrit is calculated as the slope of the line connecting the two times required to swim 200 m and 400 m. vcrit determined by this new simple method was correlated significantly with swimming velocity at 4 mmol.l-1 of blood lactate concentration (r = 0.914, P < 0.01) and mean velocity in the 400 m freestyle (r = 0.977, P < 0.01). In the maximal lactate steady-state test, the subjects were instructed to swim 1600 m (4 x 400 m) freestyle at three constant velocities (98%, 100% and 102% of vcrit). At 100% vcrit blood lactate concentration showed a steady-state level of approximately 3.2 mmol.l-1 from the first to the third stage and at 98% of vcrit lactate concentration had a tendency to decrease significantly at the fourth stage. On the other hand, at 102% of vcrit, blood lactate concentration increased progressively and those of the third and fourth stages were significantly higher than those at 100% of vcrit (P < 0.05). These data suggest that vcrit, which can be calculated by performing two timed, maximal effort swimming tests, may correspond to the exercise intensity at maximal lactate steady state.

Adolescent↗
PubMed1993

Ubenimex in the treatment of acute nonlymphocytic leukemia in adults.

A multi-institutional randomized study for the evaluation of ubenimex (Bestatin) in the treatment of adult acute nonlymphocytic leukemia was performed. One hundred and ninety-five patients were registered from February 1988 to December 1990. Patients who had reached complete remission by one or two courses of remission induction chemotherapy were divided into the ubenimex group or the control group by randomization. Patients of the ubenimex group started to receive 30 mg ubenimex orally once a day when maintenance therapy began and continued as long as possible. Remission duration and survival were analyzed based on the data as of August 31, 1991. Remission duration of the ubenimex group was superior to that of the control group (generalized Wilcoxon test: p = 0.0338). Fifty percent remission duration was 508 days in the ubenimex group and 386 days in the control group. There has been no statistical difference in survival between the two groups as yet.

Adolescent↗