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Biomedical subjects

H Asai

Publications and source records attributed to H Asai.

At least 55 records · Page 3Linked to original sources
PubMed1995

Physical activity and immune senescence in men.

A cross-sectional survey examined whether habitual endurance exercisers retained a higher level of T cell function than sedentary individuals in old age. Subjects, all male, comprised 17 elderly runners, 16 young, and 19 elderly controls (mean ages +/- SD: 63.8 +/- 3.3, 23.6 +/- 1.6, and 65.8 +/- 3.5 yr, respectively), whose resting blood samples served for the immunological tests. Compared with the young subjects, both elderly groups had lower circulating CD3+ and CD8+ cell-counts (P = 0.029, P = 0.001, respectively), with a trend to a higher CD4/CD8 ratio, but higher percentages of activated CD3+, and "memory" CD4+ and CD8+ cells (all, P < 0.0001). Proliferative responses to phytohemagglutinin, pokeweed mitogen, and alloantigens were markedly reduced in the elderly (P < 0.001, and P = 0.024, respectively). IL-2 production tended to be decreased in the elderly sedentary subjects. However, natural killer cell activity and other cytokine production remained unchanged in the elderly sedentary subjects. Comparison between the active and sedentary elderly groups showed no differences in circulating counts of immunocompetent cells. However, the active elderly subjects demonstrated significantly greater proliferative responses to phytohemagglutinin ( P = 0.016) and to pokeweed mitogen (P = 0.011), and higher rates of IL-2 (P = 0.021), IFN-gamma (P = 0.015) and IL-4 production (P = 0.012). These results suggest that endurance training in later life is associated with a lesser age-related decline in certain aspects of circulating T cell function and related cytokine production.

Age Factors↗
PubMed1994

Effects of 12 weeks of aerobic exercise plus dietary restriction on body composition, resting energy expenditure and aerobic fitness in mildly obese middle-aged women.

This study investigated the effects of 12 weeks of aerobic exercise plus voluntary food restriction on the body composition, resting metabolic rate (RMR) and aerobic fitness of mildly obese middle-aged women. The subjects were randomly assigned to exercise/diet (n = 17) or control (n = 15) groups. The exercise/diet group participated in an aerobic training programme, 45-60 min.day-1 at 50%-60% of maximal oxygen uptake (VO2max), 3-4 days.week-1, and also adopted a self-regulated energy deficit relative to predicted energy requirements (-1.05 MJ.day-1 to -1.14 MJ.day-1). After the regimen had been followed for 12 weeks, the body mass of the subjects had decreased by an average of 4.5 kg, due mainly to fat loss, with little change of fat free mass (mff). The absolute RMR did not change, but the experimental group showed significant increases in the RMR per unit of body mass (10%) and the RMR per unit of mff (4%). The increase in RMR/mff was not correlated with any increase in VO2max/mff. The resting heat production per unit of essential body mass increased by an average of 21%, but the resting heat production rate per unit of fat tissue mass remained unchanged. We concluded that aerobic exercise enhances the effect of moderate dietary restriction by augmenting the metabolic activity of lean tissue.

Body Composition↗
PubMed1994

Frequency characteristics of summating potential in Menière's disease.

SP iso-response functions in 9 patients with Menière's disease were examined for differences in the properties between +SP and -SP. The iso-response functions of +SP and -SP exhibited a large difference. The iso-response function for +SP was centered at high frequencies (around 9 kHz in most cases) with fairly steep slopes on both sides towards both higher and lower frequencies, whereas -SP showed a low-pass function. The tendency was found for patients with normal hearing at high frequencies to have a larger Q10dB than patients with a hearing loss. The difference in properties between +SP and -SP suggests the possibility that +SP may provide different information on the pathophysiology of Ménière's disease from that obtained from -SP.

Acoustic Stimulation↗
PubMed1993

[Kinetics of flomoxef sodium monitored with in vivo 19F NMR spectroscopy].

The potential usefulness of in vivo 19F NMR spectroscopy for the monitoring of flomoxef sodium (FMOX) kinetics was evaluated. In the experimental study using phantom the minimum concentration of FMOX of which signals could be monitored with 19F NMR spectroscopy was 16 micrograms/ml. In patients with intravenous bolus injection and drip infusion of FMOX (2 g/100 ml), signals from normal heart, liver, and kidney were clearly monitored with 19F NMR spectroscopy. In normal lung any signal was not detected, but in a lung with a cancer associated massive atelectasis the monitoring of signals was possible with 19F NMR spectroscopy in both intravenous and intraarterial injections. Monitoring of FMOX kinetics with in vivo 19F NMR spectroscopy will be useful in clinical applications.

Cephalosporins↗
PubMed1993

Hearing recovery following large and small fenestra stapes surgery for otosclerosis.

Fifty-five ear of 49 patients with otosclerosis were operated on with either large fenestra stapes (stapedectomy; SDE) or small fenestra stapes (stapedectomy; STO) surgery. Pre-operative average hearing levels for the speech frequency ranges (0.5, 1, 2 kHz) were 56.1 dBHL for SDE and 61.0 dBHL for STO. These improved to 39.0 dBHL and 35.0 dBHL. Statistically, significant hearing recovery was obtained for a frequency range from 0.125 to 2 kHz for SDE and from 0.125 to 4 kHz for STO (p < 0.05, Dunnett's multiple variance test). The degree of post-operative hearing improvement for STO was significantly higher at 0.5, 2 and 8 kHz than that for SDE (p < 0.05, Student's t-test). A pre-operative speech discrimination score of 80% was obtained at 68.9 dB for SDE and at 76.0 dB for STO. These values improved to 56.1 dB and 49.5 dB post-operatively. Thus, it was proved that STO results in better hearing than SDE does.

Adolescent↗
PubMed1993

The role of summating potential in the diagnosis and management of Menière's disease.

To assess the role of a negative summating potential (-SP) in the clinical diagnosis and management of Menière's disease, the relationship of -SP abnormality to clinical symptoms, hearing level and caloric test results was examined in 70 patients with unilateral Meniere's disease. The click-induced -SP and action potential (AP) were recorded by extratympanic electrocochleography. When SP/AP ratio exceeded 0.43, the -SP was considered to be abnormal. No significant relationship was found between abnormal -SP and clinical symptoms (the duration of cochlear and vestibular symptoms, recent hearing fluctuation and recent vertigo attack). Ears with abnormal -SP had a significantly worse hearing loss at high frequencies (2-8 kHz) than ears with normal -SP, whereas there was no significant difference in hearing loss at low frequencies (0.25-1 kHz) between both ears. No significant relation was found between abnormal -SP and abnormal unilateral weakness in caloric test. The results indicate that the click-induced -SP reflects the pathophysiology of Menière's disease basically in the cochlear partition at high frequencies.

Action Potentials↗
PubMed1993

[Skin test reactivity to histamine in childhood].

One hundred twenty five allergic patients ranging in age from 0 to 36 years old (mean age 9 years) were tested. Intradermal skin tests were performed on the volar surface of the forearm by injection of a five-fold dilution of histamine dihydrochloride (from 1 x 5(-5) mg/ml to 1 x 5(-2) mg/ml). The wheal diameters increased incrementally with histamine concentration. The whealing capacity of the skin to histamine was found to be significantly lower in patients 0 to 5 years of age. There was no difference in the mean wheal size between patients 6 to 10 and 11 to 15 years of age. The wheal size in patients 16 to 36 years of age were significantly larger than those in the other age groups. The flare diameters also increased incrementally with histamine concentration. The mean diameter of flares was significantly lower in patients 0 to 5 years of age. Concentrations between 1 x 5(-3) mg/ml and 1 x 5(-2) mg/ml of histamine dihydrochloride should be taken for a positive control in intradermal allergen skin tests.

Adolescent↗
PubMed1992

A collagen/gelatin-binding decapeptide derived from bovine propolypeptide of von Willebrand factor.

Propolypeptide of von Willebrand factor (pp-vWF) binds to type I collagen, and we have reported that a binding domain exists in a 21.5/21-kDa fragment originated from the C-terminal portion [Takagi, J., Fujisawa, T., Sekiya, F., & Saito, Y. (1991) J. Biol. Chem. 266, 5575-5579]. The collagen-binding property of the 21.5/21-kDa fragment was compared with that of the intact pp-vWF. Although pp-v WF preferentially binds to native type I collagen fibrils, the isolated fragment no longer has this specificity and binds well to collagen of other types in the native and heat-denatured states. In order to determine the critical site that mediates this collagen/gelatin binding, several peptides were synthesized based on the primary structure of the 21.5/21-kDa fragment. Among these, a 25-residue peptide strongly inhibited the binding of the 125I-labeled 21.5/21-kDa fragment to collagen. Using this inhibitory effect as an index, the binding site was defined to the sequence as follows: WREPSFCALS. Furthermore, a decapeptide of this sequence bound to collagen and gelatin, indicating that this sequence is responsible for the binding of the 21.5/21-kDa fragment to collagen/gelatin.

Amino Acid Sequence↗
PubMed1992

Abnormally high activity of 3-hydroxyanthranilate 3,4-dioxygenase in brain of epilepsy-prone El mice.

Quinolinic acid (QUI), a structural analogue of neurotransmitters such as L-glutamate and L-aspartate, may act as an 'excitotoxin' when it is abundant in the brain. The compound has been causally related to various neurodegenerative disorders, including epilepsy. We tested the capacity of the brains of epilepsy-prone El mice to synthesize QUI. The activity of 3-hydroxyanthranilate 3,4-dioxygenase in the cerebral cortex of El mice was about 17 times that of ddY mice, the parent strain of El mice. The activity of this enzyme was undetectable in brains of BALB/cA mice and C3H/HeN mice. In El mice the sexes had comparable enzyme activity. The enzyme activity increased gradually as the animals aged. An injection of endotoxin caused a further increase in the enzyme activity. The enzyme activity in the spleen of El mice did not differ from that of ddY mice, and endotoxin did not affect the enzyme activity in the spleen. No strain-difference was observed in the activity of quinolinate phosphoribosyltransferase, a QUI-degrading enzyme, in the cerebral cortex. These results suggest that an increase in the synthesis of QUI in the brain is involved in the pathogenesis of epileptic seizures in El mice.

3-Hydroxyanthranilate 3,4-Dioxygenase↗
PubMed1992

Initial stage of Legg-Calve-Perthes disease: comparison of three-phase bone scintigraphy and SPECT with MR imaging.

Twenty-one patients with initial stage Legg-Calve-Perthes (LCP) disease were examined by three-phase bone scintigraphy, single photon emission scintigraphy (SPECT), and magnetic resonance (MR) imaging. On dynamic study, increased activity was present in the epiphysis or the growth plate in 39%; the corresponding figure for blood-pool images was 94%. Pinhole images demonstrated the lateral stripe of revascularization in 57% of patients. Decreased signal intensity in the epiphysis on T1-weighted images proved to be the most sensitive indicator of epiphyseal necrosis on MR imaging and was absent in only 10% of the cases. The subchondral fracture occurred in 62% (including the above 10% of cases), identified by T1-weighted image. Cartilaginous hypertrophy, detected by T1-weighted image, had a high incidence (81%). Joint effusion was identified on T2-weighted images in 90% of patients. The cross-sectional views provided by SPECT and MR imaging permits a better appreciation of the extent of epiphyseal necrosis in LCP disease.

Bone and Bones↗
PubMed1992

[An electron microscopic study on osteoblastoma--ultrastructure and fine localization of alkaline phosphatase].

Three cases of osteoblastoma were studied by electron microscopy. They included two cases of conventional osteoblastoma and one case of aggressive osteoblastoma. In conventional osteoblastoma, ultrastructural features and location of alkaline phosphatase activity of the osteoblast-like cell were similar to those of normal osteoblast. On the other hand, aggressive osteoblastoma cell (case 3) showed different structure from those of a normal osteoblast; the nucleus of the tumor cell showed irregular surface with a small degree of heterochromatin, and poorly developed cytoplasmic organellae. Cytochemically, alkaline phosphatase activity was noted not only on the cytoplasmic membrane, but on the abundant vesicles in the cytoplasm. From these findings we conclude that the aggressive osteoblastoma cells are more immature in morphology and show increased synthesis of alkaline phosphatase.

Adolescent↗
PubMed1991

[MR imaging of the vestibular aqueduct in normal volunteers and patients with Menière's disease--a preliminary report].

In this paper we attempted MR visualization of the vestibular aqueduct (VA) with a surface coil. Sagittal plane was most preferable from the result of preliminary study using a dry temporal bone. In all of ten normal volunteers, VAs were visualized well. In none of them, proton-density weighted spin-echo (SE) images were inferior to both T1- and T2-weighted SE image. In four of eight patients with Menière's disease, VAs were not visualized due to obstruction of VA, although in all of ten non-Menière's patients with hearing loss or vertigo, VAs were well visualized. Although further investigation is needed, MR imaging of VA including both its content and surrounding bony structure would give important information to manage the patients with either Menière's disease or other disorders of internal ears.

Adult↗
PubMed1991

Breathing patterns during sleep in stable asthmatic children.

Breathing patterns during sleep at night were studied in 15 asymptomatic asthmatic children and 11 nonasthmatic controls using impedance pneumography. Inspiratory time (TI), expiratory time (TE) and expiratory time/inspiratory time ratio (TE/TI) were used as the indices of breathing patterns. In the daytime, TI, TE and TE/TI, showed no significant differences between asthmatics and controls. During nocturnal sleep, TE and TE/TI increased significantly in the asthmatics compared with the value during daytime, while these values showed only a small variation overnight in the controls. TI showed no significant changes through the night in either the asthmatics and the controls. The results of this study indicate that the stable asthmatic children had abnormal breathing patterns during nocturnal sleep.

Adolescent↗
PubMed1991

[Carbohydrate antigens as a tumor-associated antigen and prognostic indicators in carcinomas of the breast, esophagus, stomach, colorectum, and pancreas].

The immunohistochemical analysis using the monoclonal antibodies to the carbohydrate antigens were performed and suggested that CA19-9 is a tumor-associated antigen in gastric cancer, Leb, Ley, CA19-9, CSLEX1, SLX in colorectal cancer and pancreatic cancer, and Lex, Ley, and CSLEX1 in breast and esophageal cancers, respectively. Expression of the type 2 carbohydrate antigens had relation to the prognosis of patients with breast cancer. In colorectal cancer, the patients with high degree of expression of CA19-9 had a poor prognosis, and high risk of distant metastasis. Higher intensity of staining was observed in hepatic in comparison with primary lesion. Thus carbohydrate antigens showed important role as tumor-associated antigens and good indicator for evaluation of prognosis.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1990

Clinical significance of positive summating potential in Menière's disease.

The positive summating potential (+SP) in Menière's disease was compared with that in normal ears and in cochlear deafness of other origin than endolymphatic hydrops in order to assess a specificity of the +SP in Menière's disease. The +SP was recorded in 21 of 47 Menière ears (45%) on stimulation with 8-kHz tone bursts, whereas the +SP was recorded in none of 10 normal-hearing ears and in 1 of 28 ears with cochlear deafness of other origin than endolymphatic hydrops (4%). The incidence of the +SP in Meniére's disease was higher on stimulation with 8-kHz tone bursts than with 4-, 2- and 1-kHz tone bursts and clicks. No correlation between SP amplitudes recorded with 2- and 8-kHz tone bursts was found. The results suggest that Menière's disease may involve a pathophysiological condition which allows the +SP to be frequently recorded.

Acoustic Stimulation↗
PubMed1990

Relationship between results of electrocochleography and caloric test in Menière's disease.

The relationship between an increase in the negative summating potential (-SP) and the results of caloric tests was examined in 35 patients with unilateral Menière's disease. The -SP was recorded by extratympanic electrocochleography. The quantitative bithermal caloric test was performed by irrigating with cool (30 degrees C) and hot (44 degrees C) water. An increased -SP was recorded in 20 of 35 patients (57%). Abnormal unilateral weakness (UW) on the involved side and abnormal directional preponderance (DP) to the involved side were observed in 16 of 35 (46%) and in 4 of 35 patients (11%), respectively. No significant correlation was found between an increased -SP and an abnormal UW and DP in Menière's disease.

Audiometry, Evoked Response↗