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Biomedical subjects

K Aoki

Publications and source records attributed to K Aoki.

At least 559 records · Page 31Linked to original sources
PubMed1991

Effect of sleep on binaural interaction in human auditory evoked potentials.

Binaural interaction (BI) in ABR, MLR and two kinds of 40-Hz steady-state responses (SSRs) were measured in the waking and sleeping states in normal adults. Eleven samples each were collected from 20 subjects. The ABR and MLR were elicited with 500-Hz tone pips. The SSRs were elicited with the same tone pips (pipSSR) or sinusoidally amplitude-modulated tones of the same frequency (samSSR). The amplitude differences between the summed monaural and binaural responses relative to the summed monaural responses were referred to as BI. ANOVA showed that the mean BI in the responses tested was significantly lower (p < 0.005) in the sleeping state than in the waking state. Ad hoc analysis revealed that the significant difference (p < 0.05) in BI between the waking and sleeping states occurred in the pipSSR and samSSR. The BI became larger in the order, ABR, samSSR, pipSSR, MLR, in both the waking and sleeping states. Significant differences (p < 0.05) were detected in the BI during sleep between the MLR and each of the other three responses, whereas in the waking state no significant difference was found between the MLR and tone-pip SSR.

Acoustic Stimulation↗
PubMed1991

[The relation between ECG findings and lesions of acute and old myocardial infarction in autopsy cases].

Sixty-four elderly autopsy cases with acute myocardial infarction (AMI) were investigated in Nagoya Koseiin Geriatric Hospital. First AMI was observed in 35 cases, and recurrent AMI in 29. The primary causes of death were cardiac rupture and congestive heart failure in the first AMI and the recurrent AMI, respectively. The most frequent ECG findings before AMI were ischemic ST-T-change (57%) and Q-QS abnormality (41%) on the first and recurrent AMI, respectively. The ECG findings were normal in 6 (21%) of 29 recurrent MI cases. There was a tendency towards Q-QS abnormality in large size old MI, but not in small size MI. In 29 cases with recurrent AMI, the positional relationship between the old MI and the AMI was classified into 3 groups of different area, same area, and different and same area according to the Maccarie classification. The frequency in our cases was similar in the 3 groups. Ten cases with different area were further classified into 3 groups, i.e. opposite, adjacent, and opposite and adjacent. Opposite cases consisted of 4 (40%) cases, while opposite and adjacent consisted of 6 (60%). It is suggested that the recurrent AMI is more likely to be fatal when AMI occurs opposite to a previous lesion rather than adjacent to an old lesion.

Aged↗
PubMed1991

[Visual scoring in the auditory brainstem response. Second report: determination of response threshold].

In the ABR audiometry we usually determine the threshold by visual scoring. The evaluation of visual scoring has been investigated in my laboratory for several years, using the traced samples of ABR obtained from 3 normal adults same as that described in my previous report. Stimuli were clicks of 0, 5, 10, 15, 20, 30dBSL and without stimulus. Thresholds were calculated by the two psychophysical methods, "method of limits" and "up and down method". Scorers were two groups: 3 experienced and 3 inexperienced. Results obtained were as follows: 1. In the method of limits, averages of thresholds measured by the experienced scorers were contained 6.0-9.8dB, their standard deviations being 3.82-6.40dB. 84-95% of all thresholds were contained 0-10dB or 5-10dB in the experienced group. 2. In the method of limits, the highest rate that all scorers of a group had the same threshold was 56% in the separate presentation in the experienced group. 3. In the up and down method averages of threshold were contained 4.6-9.1dB, which were smaller than the method of limits, and standard deviations were contained 1.77-3.18dB, which were about 1/2 times in the method of limits. 92-99% of all thresholds were contained 0-5dB or 5-10dB.

Audiometry, Evoked Response↗
PubMed1991

[Formation of sexual identity among 9th grade girls].

The present study was to explore the molding of sexual identity in early-adolescent females. First, a questionnaire was administered to 168 9th grade girls. Out of all the respondents, 12 who did not have conflicts with sexual identity as an accepting group and 10 who had them as a non-accepting group were selected for the interview. Analyses of the results revealed that the contents of their conflicts cover various phases of femininity, which are concerned with body, character, and sex role etc. Moreover, it was found that not only their good images of parents, but also those of males were important when they achieve their sexual identity.

Adolescent↗
PubMed1991

[In vitro antifungal activity of itraconazole, a new triazole antifungal agent, against clinical isolates from patients with systemic mycoses].

The in vitro antifungal activity of itraconazole (ITZ), a new oral triazole antifungal agent, against clinical isolates from patients with systemic mycoses were compared with those of existing systemic antifungals, viz. ketoconazole (KCZ), miconazole or amphotericin B. The studies were performed with 65 isolates of pathogenic yeasts and 13 isolates of Aspergillus spp. using the agar dilution method on casitone agar. ITZ showed the most potent antifungal activities against isolates of pathogenic yeasts including several Candida spp. (Candida parapsilosis, Candida krusei, Candida guilliermondii), Cryptococcus neoformans, Trichosporon cutaneum (MIC less than or equal to 0.08 micrograms/ml) and Aspergillus spp. including Aspergillus fumigatus (MIC less than or equal to 5 micrograms/ml). On the other hand, activities of ITZ against isolates of other Candida spp. such as Candida albicans and Candida glabrata were lower than those of KCZ and other reference drugs. Some isolates of C. albicans and C. tropicalis were not completely inhibited by ITZ even at concentrations above 10 micrograms/ml on casitone agar. However, in the micro-broth dilution method using synthetic amino acid medium, fungal as the test medium, ITZ completely inhibited the growth of all these isolates at drug concentrations of less than or equal to 0.20 micrograms/ml.

Amphotericin B↗
PubMed1991

[In vitro antifungal activity of itraconazole, a new triazole antifungal agent, against clinical isolates from patients with dermatomycoses].

In vitro antifungal activities of itraconazole (ITZ), a triazole antifungal agent, against clinical isolates obtained from patients with superficial and subcutaneous mycoses were examined using the agar dilution method on casitone agar. The clinical isolates tested were 7 species and 263 isolates including Trichophyton mentagrophytes (104 isolates), Trichophyton rubrum (103 isolates), Microsporum canis (3 isolates), Epidermophyton floccosum (2 isolates), Candida albicans (32 isolates), Malassezia furfur (7 isolates) and Sporothrix schenckii (12 isolates). The results are summarized as follows: 1. MIC values of ITZ for the isolates of dermatophytes and M. furfur distributed in a range of less than 0.0012-5 micrograms/ml indicating that ITZ had greater in vitro activities. These in vitro activities of ITZ were greater than those of clotrimazole or bifonazole. 2. C. albicans isolates were divided into 2 groups in terms of ITZ-susceptibilities, a high susceptibility group and low-susceptibility group with MIC values of 0.02-0.08 micrograms/ml and greater than 10 micrograms/ml, respectively. 3. The in vitro activities of ITZ against S. schenckii isolates with a geometric mean MIC of 0.119 micrograms/ml were greater than those of ketoconazole, miconazole or amphotericin B used as reference drugs.

Amphotericin B↗
PubMed1991

Characteristic changes of the GABAA receptor in the brain of phenobarbital-dependent and withdrawn rats.

The changes of the GABAA receptor in the brain of phenobarbital (PB)-dependent and -withdrawn rats were investigated using [3H]-muscimol (a potent agonist of GABAA receptor) as the ligand. The dissociation constant for a low affinity binding site (Kd2) of PB-dependent rats significantly increased without affecting the high affinity site (Kd1) and Bmax for both sites. A decrease of specific [3H]-muscimol binding was observed in the whole brain and the cerebellum of the PB-dependent rats, when examined at a fixed drug concentration of 2 nM. Moreover, the specific [3H]-muscimol binding in the withdrawn rats was remarkably lower than that of the dependent rats. These results suggest that the change of the GABAA receptor may be related to the development of PB-dependence and -withdrawal.

Animals↗
PubMed1991

[A method of interval estimation for number of patients in the nationwide epidemiological survey on intractable diseases].

A method for estimating the intervals for the number of patients with intractable diseases from nationwide epidemiological surveys was developed under the assumption that response is independent of frequency of patients. This method is based on data utilizing the number of response hospitals classified by their reported number of patients. The approximate 95% confidence intervals of numbers of several intractable diseases patients were estimated using this method.

Data Interpretation, Statistical↗
PubMed1991

[Evaluation of methods for measuring daily physical activity in terms of energy expenditure].

Various methods exist for measuring daily physical activity and daily energy expenditure and daily pedometer readings are most commonly used for the amount of physical activity. In this study, three methods for measuring energy expenditure-24-hr heart rate method (HR), time study method, and caloric expenditure accumulator (CC)-, and the feasibility of a pedometer for the assessment of energy expenditure were examined under laboratory conditions and during normal daily life. Daily physical activity was measured by four methods (HR, Time study, CC, Pedometer) in a field study of 14 young, healthy and sedentary women, and compared. Laboratory validation of the three methods with measurement of oxygen uptake was performed with 5 young men and 1 woman walking and running at different speeds and grades on a treadmill. In addition validation tests of whether pedometer readings reflect differences in energy expenditure due to speed and grade and whether pedometer counts steps exactly were also conducted. The 24-hr energy expenditure derived from CC was significantly lower than that derived from HR and Time study, due to lower estimation of energy expenditure from activities compared to other methods. In the laboratory study, the energy expenditure measured at 5% grade was low by CC and differences in energy expenditure for changes in grade could not be differentiated. Time study revealed a significant relationship between CC and HR in field study. These results suggest that CC tends to underestimate the 24-hr energy expenditure from activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Spontaneous massive hemorrhage within a malignant tumor of the liver: diagnostic features in sonography and CT.

Computed tomography (CT) and sonography performed on four patients with histopathologically proven massive intratumoral hemorrhages in the liver were compared with pathological findings. Unenhanced CT showed a round low-density mass, and enhanced CT produced slight enhancements in the peripheral portions of the masses in two patients which corresponded to histopathologically viable cancerous portions. In contrast, sonography showed multilocular cystic masses with variously shaped septa, assuming a honeycomb appearance. Histopathologically, the septa were made up of blood clots with or without granulation tissue, scar and viable tumor, and the cystic spaces were filled with exudate and erythrocytes. Combined study by CT and sonography could be useful in differentiating massive hemorrhagic malignancies from cystic and necrotic masses and/or simple hemorrhagic lesions. The danger of malignant tumors with massive hemorrhage possibly being diagnosed as benign lesions, such as hematomas and abscesses, is also stressed.

Adolescent↗
PubMed1991

[Usefulness of recombinant human erythropoietin in cardiac surgery with autologous blood transfusion].

The efficacy and method of administration of recombinant human erythropoietin (EPO) in adult cardiac surgical patients when given preoperatively was evaluated. We used EPO intravenously (iv) with 40 mg ferric oxide for a total of consecutive 47 patients. The patients were divided into group A (n = 14; EPO 200 IU/kg iv 3 times a week from 3 weeks prior to surgery to 2 weeks after surgery, donation of 800 ml) and group B (n = 33; EPO 200 IU/kg iv everyday from 8 days prior to surgery to 2 weeks after surgery, donation of 400 ml). Control groups were group AO (n = 11; donation of 835 +/- 33 ml from 14.8 days prior to surgery) and group BO (n = 7; donation of 406 +/- 34 ml at 7.3 days prior to surgery). All the EPO-treated patients received no homologous blood transfusion while 2 of patients in group BO received some homologous blood transfusion. A hemoglobin change between pre-donation and surgery was +0.14 +/- 1.3 (g/dl) in group A, +0.04 +/- 1.0 (g/dl) in group B, -1.7 +/- 1.3 (g/dl) in group AO and -1.0 +/- 0.6 (g/dl) in group BO. In a comparison of post-surgical hemoglobin levels between group A and group B, we demonstrated that the level in group B, +2.1 +/- 1.8 (g/dl) was significantly higher than that in group A, +11.1 +/- 1.6 (g/dl) 2 weeks after surgery. There was no evidence to show an aggravation of anemia in the pre-surgical period in EPO-treated groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Anemia↗
PubMed1991

The failure of increased serum potassium to enhance the pressor response to infused calcium in normotensive men.

We evaluated the effects of an increased serum potassium level, the result of a potassium infusion, on the pressor response to infused calcium in normotensive men. Potassium infusion (0.38 mmol/kg per h for 2 h) increased serum potassium by 1.1 mmol/l with no changes in blood pressure, cardiac output or total peripheral vascular resistance (n = 6). Calcium infusion (0.19 mmol/kg per h for 1 h) and combined infusion of potassium followed by calcium increased serum calcium by 1.1 mmol/l with an elevated blood pressure, vascular resistance and no change in cardiac output (n = 8). The absolute and per cent increases in blood pressure and vascular resistance during the calcium infusion did not differ in the absence compared with in the presence of an increased serum potassium. These results indicate that a small increase in serum potassium did not modify the pressor response to infused calcium. We conclude that hypercalcaemia-induced hypertension is caused by direct effects of calcium on arterial smooth muscle.

Adult↗
PubMed1991

Low frequency components of the body's center of gravity and blood circulation.

The purpose of this study was to clarify how low frequency components of the body's center of gravity, mainly 1 minute waves (1-MWs), are related to the mechanism of compensation for the venous blood pooling in the legs during static standing in humans. The 1-MWs of foot pressure center, oscillations of body circumferences and other parameters were analyzed with cross-power spectral analysis. The 1-MW of the calf's blood volume propagated to the chest via the venous system. This was inversely synchronized with the 1-MW of the body's center of gravity. It was speculated that muscular pumping of the calf related to the 1-MW of the body's center of gravity might be compensating for the venous blood pooling in the legs.

Adult↗
PubMed1991

[In vitro antifungal activities of amorolfine against fresh isolates from patients with cutaneous mycosis].

In vitro antifungal activities of amorolfine (MT-861), a new morpholine antifungal agent, were examined using an agar-dilution method, in comparison with those of 2 other antifungal agents, clotrimazole (CTZ) and bifonazole (BFZ), against 182 clinical isolates of Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis, and Epidermophyton floccosum, which had been freshly isolated from a total of 182 cutaneous mycotic patients with various types of dermatophytes or cutaneous candidiasis. Antifungal activities of the 3 drugs against T. rubrum were in the order of MT-861 greater than CTZ greater than BFZ, with the lowest average MIC values (0.0070 micrograms/ml) obtained with MT-861. The average MIC value of MT-861 for clinical isolates from patients with pedis was roughly 2.3-fold higher than that for those from patients with tinea corporis. Out of 3 drugs tested MT-861 exhibited the most potent activities against clinical isolates of T. mentagrophytes, M. canis, and E. floccosum with average MIC values of 0.0267, 0.0079, and 0.0018 micrograms/ml, respectively. MIC values of MT-861 against isolates of Candida albicans ranged from 0.01 to 10 micrograms/ml, and the average value (0.1762 micrograms/ml) was the lowest of the 3 drugs.

Antifungal Agents↗
PubMed1991

[In vitro antifungal activity of amorolfine against Malassezia species].

In vitro antifungal activities of a new morpholine agent, amorolfine (MT-861) were investigated, against 39 strains of Malassezia furfur (11 stock cultures and 28 clinical isolates) and 8 strains (stock cultures) of Malassezia pachydermatis, in comparison with those of 2 reference drugs, clotrimazole (CTZ) and bifonazole (BFZ). Of the 3 antifungal agents, MT-861 exhibited strongest antifungal activities against the stock cultures of M. furfur and M. pachydermatis with average MIC values of 0.428 and 0.174 micrograms/ml, respectively; and the average BFZ activity was less than 1/10, and the average CTZ activity was 1/100, of the average MT-861 activity. All of the clinical isolates of M. furfur also showed high susceptibilities, though they were more susceptible to BFZ and CTZ.

Antifungal Agents↗
PubMed1991

[Acute leukemia successfully treated with natural interferon-alpha].

Natural interferon-alpha (IFN-alpha) alone was administered to a 42-year-old man with acute leukemia, whose bone marrow revealed hypocellularity (NCC = 6 X 10(4)/microliters) and a 50% increase in blasts. Initial chemotherapy regimens, including BHAC-DMP or low dose Ara-C were ineffective. One month after starting nIFN-alpha therapy, the blasts in his bone marrow decreased below 3% and peripheral blood cell counts became normal. He has been in remission for at least 7 months.

Acute Disease↗