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Biomedical subjects

S Aoki

Publications and source records attributed to S Aoki.

At least 415 records · Page 23Linked to original sources
PubMed1991

[Effect of road traffic noise on sleep. A paired comparison between sleep polygraphic parameters recorded in a noisy apartment along a road with heavy traffic and those recorded in a quiet suburban house].

Effects of road traffic noise on sleep were studied comparing 15 sleep polygraphic parameters and 6 subjective sleep complaints in a noisy apartment with those in a quiet house. Subjects were 8 persons (5 young men aged 19-38, one woman aged 65 and 2 men aged 66) and were studied for 76 nights. The average equivalent sound pressure level (Leq) from 10 p.m. to 7 a.m. was 46.67 dB (A) in the noisy apartment's bedroom compared to 27.72 dB(A) in the bedroom of the quiet house. Of the 15 parameters, proportion of REM sleep for the younger subjects was significantly less (p = 0.0046, paired t-test) in the apartment compared to the quiet house. No significant difference was seen in the remaining 14 parameters between the apartment and the house. Of the 6 subjective sleep complaints, "awakened early in the morning," was significantly less for young subjects (p = 0.031, Two-tailed sign test) in the apartment than in the house. There was no significant difference seen for the older subjects in the 6 subjective sleep complaints and 15 sleep polygraphic parameters between the two places. It appears that a small difference in the effect of road traffic noise on sleep between young and old may exist.

Adult↗
PubMed1991

[Effects of lumbar epidural anesthesia on brainstem auditory response].

Auditory brainstem responses (ABR) are used increasingly to monitor the integrity of neural pathways in anesthetized patients. To evaluate the effect of epidural anesthesia on the central nervous system, we studied the effects of lumbar epidural anesthesia with lidocaine on the ABR in 10 patients. The seven peak latencies (waves I-VII) and amplitudes (waves I-VII) of the ABR were recorded before and 15 min after epidural anesthesia. Peak latencies of waves III, IV, V, VI, VII increased after epidural anesthesia compared with control values. Amplitude of waves II only decreased significantly following epidural anesthesia compared with control values. We further compared the interpeak latencies to investigate the brainstem transmission. Interpeak latencies (I-II, II-III, III-IV, IV-V, V-VI, VI-VII) were unchanged from the control values except waves VI-VII interval. Interpeak latencies of every second peak (II-IV, IV-VI, V-VII), of every third peak (II-V, III-VI, IV-VII), of every forth peak (I-VI, II-VII), of every fifth peak (I-VII) increased after epidural anesthesia compared with control values. The data obtained in the study demonstrated that lumbar epidural anesthesia with lidocaine prolonged the interpeak latencies of ABR. Considering that the waves of ABR are related to anatomically distinct sites in the auditory pathway (I; Acoustic nerve, II; Cochlear nucleus, III; Superior olivary complex, IV; Lateral lemniscus, V; Inferior colliculus, VI: Medial geniculate body, VII; Auditory radiation), the delay in the latencies of ABR seems to be present in the time intervals which involve more than two or three synaptic transmissions.

Anesthesia, Epidural↗
PubMed1990

[Development of all-silicone detachable balloons].

Treatment of cerebral vascular lesions such as carotid cavernous sinus fistulas and giant aneurysms is now being performed with intravascular detachable balloon embolization techniques. We have developed several types of all-silicone detachable balloons. Our balloons have self-sealing valves (with or without collars) and detach with simple traction. The self-sealing valve is smaller than 0.6 mm and the balloon can easily be placed through a 7-F catheter. We started clinical trials and a representative case was reported.

Embolization, Therapeutic↗
PubMed1990

[Doppler ultrasonic assessment with hemodynamics of gynecologic tumor].

Color and pulsed Doppler ultrasound examinations were done on 11 normal volunteers (NU) and 286 patients that consisted of cervical carcinoma (CC), leiomyoma and/or adenomyosis (M), endometrial carcinoma (EC), trophoblastic disease (TD), benign ovarian tumor (BO), Krukenberg tumor (KT) and ovarian carcinoma (OC). The vascularity was based on the resistance index (RI) and maximum blood flow velocity (Vmax). In uterine disease, there was significant difference (p less than 0.01) among each group, except but one correspondence between NU and CC with RI, and there was significant difference (p less than 0.001) between NU and M, CC and M with Vmax. In ovarian disease, there was significant difference among each group with RI, and there was no significant difference among each group with Vmax. Therefore, Doppler ultrasound is a useful diagnostic tool for assessing gynecologic tumor vascularity.

Blood Flow Velocity↗
PubMed1990

Parametrial invasion of uterine cervical cancer assessed by transrectal ultrasonography: preliminary report.

Transrectal ultrasonographic examinations were performed on 30 patients with uterine cervical cancer to assess parametrial invasion. The findings were compared with data obtained by manual rectal examination. Forty-six parametria in 23 patients were histologically examined following surgery. Sensitivity, specificity, positive predictive value, negative predictive value, and predictive accuracy of transrectal ultrasonography and rectal examination were 1.0 and 0.25 (P less than 0.05), 0.9 and 0.93, 0.5 and 0.25, 1.0 and 0.93, and 0.91 and 0.87, respectively. Therefore, transrectal ultrasonography may prove to be a useful diagnostic tool to determine the preoperative staging of uterine cervical cancer.

Diagnostic Errors↗
PubMed1990

Comparative pathogenicity of a wild-type strain and respiratory mutants of Candida albicans in mice.

The pathogenicity of a parent wild-type strain and three respiratory mutants of Candida albicans was examined in intravenously infected mice. The wild-type strain K grew well in the kidney and caused severe candidosis, and the 21-day LD50 value was 7.2 x 10(6) cells/mouse. A mutant with a low rate of respiration (KRD-8) whose growth rate in vitro was somewhat lower than that of the wild type, produced germ tubes in vitro to the same extent as the wild-type strain and was associated with mortality rates similar to those of the wild-type strain. Two respiration-deficient (petite) mutants (KRD-19 and KRD-51), whose growth rates in vitro were far lower than that of the wild-type strain, could neither colonize the kidney nor cause fatal infection, even at a dose of 10(8) cells/mouse. Formation of germ tubes and hyphal growth in vitro of the petite mutants were less extensive than those of the wild-type strain or KRD-8. Extracellular proteinase was produced at pH 3.5 by the wild-type strain and by KRD-8 but not by the petite mutants. From these results, it is most likely that the nonlethality of infection by the petite mutants in mice results primarily from the low capacity of growth of these mutants, even though the inability of the petite mutants to produce extracellular proteinase may be also related to some extent to their avirulence.

Animals↗
PubMed1990

Acid-stable 2'-fluoro purine dideoxynucleosides as active agents against HIV.

2',3'-Dideoxy purine nucleosides have anti-HIV activity in vitro and the inosine analogue is being clinically evaluated. The instability of these compounds toward acidic conditions complicates oral administration. The effect of the addition of a fluorine atom to the 2'-position was investigated by preparing the fluorine-containing 2'-erythro and 2'-threo isomers of ddA and the threo isomer of ddI. All fluorine-containing compounds were indefinitely stable to acidic conditions which completely decomposed ddI (1) and ddA (2) in minutes. While the fluorine-containing erythro isomer, 5, was inactive, the threo isomers, 2'-F-dd-ara-A (3) and 2'-F-dd-ara-I (4), were just as potent and active in protecting CD4+ ATH8 cells from the cytopathogenic effects of HIV-1 as the parent drugs. Exposure to pH 1 at 37 degrees C prior to testing destroyed the activity of ddA and ddI but left the anti-HIV properties of 3 and 4 unchanged. The fluorinated analogues also protected cells exposed to HIV-2 and inhibited gag gene product expression but not as effectively as the parent compounds. The fluorine-containing analogues appear to be somewhat more toxic in vitro to the antigen- and mitogen-driven proliferation of immunocompetent cells than their corresponding parent compounds.

Antiviral Agents↗
PubMed1990

Lipophilic halogenated congeners of 2',3'-dideoxypurine nucleosides active against human immunodeficiency virus in vitro.

Four 2-amino-6-halo- and four 6-halo-2',3'-dideoxypurine ribofuranosides (ddPs) were synthesized and tested for in vitro activity to suppress the infectivity, cytopathic effect, Gag protein expression, and DNA synthesis of human immunodeficiency virus (HIV). The comparative order of in vitro anti-HIV activity of the eight 6-halo-ddPs was as follows: 2-amino-6-fluoro, 2-amino-6-chloro, 6-fluoro greater than 2-amino-6-bromo greater than 2-amino-6-iodo, 6-chloro greater than 6-bromo greater than 6-iodo. 2-Amino-6-fluoro-, 2-amino-6-chloro-, and 6-fluoro-ddPs showed a potent activity against HIV comparable to that of 2',3'-dideoxyinosine (ddI) or 2',3'-dideoxyguanosine (ddG) and completely blocked the infectivity of HIV without affecting the growth of target cells. The lipophilicity order was as follows: 2-amino-6-iodo greater than 2-amino-6-bromo greater than 2-amino-6-chloro greater than 2-amino-6-fluoro much greater than ddG greater than ddI. All eight 6-halo-ddPs were substrates for adenosine deaminase (ADA; adenosine aminohydrolase, EC 3.5.4.4). The relative rates of hydrolysis by ADA were as follows: ddA, 2-amino-6-fluoro much greater than 2-amino-6-chloro, 2-amino-6-bromo greater than 2-amino-6-iodo. Taken together, these compounds may represent an additional class of lipophilic prodrugs for ddI and ddG and may also provide a strategy for endowing therapeutic purine nucleosides with desirable lipophilicity.

Antiviral Agents↗
PubMed1990

Quantitative analysis of HIV-1 proviral DNA in peripheral blood mononuclear cells from patients with AIDS or ARC: decrease of proviral DNA content following treatment with 2',3'-dideoxyinosine (ddI).

A rapid and simple method for determining the proviral DNA content in peripheral blood mononuclear cells (PBM) from patients with human immunodeficiency virus type 1 (HIV-1) infection was established by using the polymerase chain reaction (PCR) technique. We found that the majority of HIV proviral DNA copies detectable in unfractionated PBM resided in T cells, while B cells/monocytes contained lesser amounts of HIV DNA (93.9 +/- 3.5% for T cells vs. 6.1 +/- 3.5% for B cells/monocytes: p less than 0.05). When we compared the amount of HIV proviral DNA in PBM from 13 patients with AIDS or AIDS-related complex (ARC) before and during antiretroviral therapy with 2',3'-dideoxyinosine (ddI) which was given as an escalating dose in a Phase I clinical study, a significant decrease was observed in 9 of 12 evaluable patients receiving the drug for 8 to 14 weeks (p less than 0.02). The decrease appeared more pronounced in patients receiving relatively high doses of the drug. These data suggest that the quantitation of HIV viral DNA in PBM by PCR is feasible and may theoretically contribute to an overall monitoring of patients receiving experimental therapy. However, larger studies will be required to determine the sensitivity and specificity of this assay and further longitudinal studies will be essential.

AIDS-Related Complex↗
PubMed1990

Effects of preventive, early, and late antifungal chemotherapy with fluconazole in different granulocytopenic models of experimental disseminated candidiasis.

To investigate the potential use of fluconazole for prevention and treatment of disseminated candidiasis in granulocytopenic patients, its in vivo antifungal activity was studied in three models of disseminated candidiasis in persistently granulocytopenic rabbits: acute, subacute, and chronic disseminated candidiasis. Fluconazole was compared with the combination of amphotericin B and flucytosine for preventive, early, and late treatment of disseminated candidiasis, depending on the model. Fluconazole was most effective when used for preventive or early treatment of acute and subacute disseminated candidiasis. When compared with the combination of amphotericin B plus flucytosine, fluconazole was similarly effective in early treatment of acute and subacute disseminated candidiasis. When treatment was delayed 6 days after established infection, fluconazole was less active in clearing tissues in comparison with its activity in preventive and early treatment. The combination of amphotericin B plus flucytosine, however, was significantly more active than fluconazole in treatment of chronic disseminated candidiasis in all tissues. In summary, fluconazole was most effective against disseminated candidiasis in persistently granulocytopenic rabbits when used for prevention or early treatment.

Acute Disease↗
PubMed1990

Change in ovarian arterial compliance during the human menstrual cycle assessed by Doppler ultrasound.

Ovarian arterial velocimetry, using real-time two-dimensional and pulsed Doppler ultrasound, was performed on 36 occasions in nine healthy women with regular menstrual cycles. The change in ovarian arterial compliance was based on the calculation of pulsatility index (PI). In the active ovary carrying a dominant follicle or corpus luteum, the PI in the early follicular phase (mean 6.97, SD 2.01) was significantly higher than that in the late follicular phase (mean 2.36, SD 0.31) (P less than 0.001), and the PI in the early luteal phase (mean 0.68, SD 0.09) was significantly lower than that in the late follicular phase (P less than 0.001). The PI in the late luteal phase (mean 0.93, SD 0.16) was significantly higher than that in the early luteal phase (P less than 0.01). In the inactive ovary, no cyclical changes were seen in the values of PI. There was a significant difference between the values of PI in the active ovary and the inactive ovary in the late follicular, the early and the late luteal phases [2.36 (SD 0.31)] vs [6.29 (SD 1.02)], [0.68 (SD 0.09)] vs [6.18 (SD 1.33)], [0.93 (SD 0.16) vs [6.57 (SD 1.72)] (P less than 0.001), respectively. Use of non-invasive Doppler ultrasound to study physiology of ovarian haemodynamics during the menstrual cycle is of great clinical relevance and paves the way for further investigations on sterility.

Adult↗
PubMed1990

Antigen challenge induces pulmonary airway eosinophil accumulation and airway hyperreactivity in sensitized guinea-pigs: the effect of anti-asthma drugs.

1. Guinea-pigs were sensitized with 3 injections of ovalbumin (OA) (1 or 10 micrograms per animal) using Al(OH)3 and pertussis vaccine as adjuvants at two week intervals. 2. Sensitized guinea-pigs were challenged with an aerosol of OA (0.1%) over a one hour period and both airway reactivity and cellular content of bronchoalveolar lavage (BAL) fluid were assessed at intervals for up to 7 days. 3. Guinea-pigs sensitized with 1 microgram of ovalbumin responded to an aerosol of OA with increased pulmonary airway eosinophilia, which was evident 1 day after challenge and was present for up to 7 days. Airway hyperreactivity was not detectable in these animals. 4. Guinea-pigs sensitized with 10 micrograms of ovalbumin responded to an aerosol of OA with increased pulmonary airway neutrophilia and eosinophilia and with increased airway reactivity which was maximal between 8 and 24 h after exposure to OA. 5. Depletion of circulating platelets or neutrophils, by use of selective antisera, did not alter either the magnitude of eosinophilia or the intensity of airway reactivity in sensitized guinea-pigs (10 micrograms) exposed to an aerosol of OA. 6. Pretreatment of sensitized guinea-pigs (10 micrograms) for 6 days with AH 21-132, aminophylline, dexamethasone or ketotifen inhibited pulmonary airway eosinophilia, but did not diminish airway hyperreactivity. Neither eosinophil accumulation nor development of airway hyperreactivity was influenced by treatment with mepyramine or salbutamol over a 6 day period before OA inhalation. 7. Although eosinophilia may occur in association with increased airway reactivity in this animal model, there is no evidence of a causal relationship.

Animals↗
PubMed1990

Eosinophil accumulation in pulmonary airways of guinea-pigs induced by exposure to an aerosol of platelet-activating factor: effect of anti-asthma drugs.

1. Exposure of guinea-pigs to aerosols of platelet activating factor (PAF) (0.01 to 100 micrograms ml-1) induced a dose-dependent increased incidence of eosinophils in bronchoalveolar lavage fluid (BAL) at 48 h. Total leucocyte numbers and the percentages of lymphocytes and neutrophils were unchanged in BAL fluid. 2. Increased numbers of eosinophils were detected in BAL 1 h after exposure to PAF but eosinophilia was not maximal until 48 h. One week after exposure to PAF, the percentage of eosinophils in BAL was within the normal range. 3. Depletion of circulating platelets or neutrophils by intravenous injection of specific antisera did not modify accumulation of eosinophils in the airway lumen following inhalation of PAF (10 micrograms ml-1). 4. PAF-induced pulmonary airway eosinophil accumulation was inhibited by treatment with SDZ 64-412, a selective PAF-antagonist, whether the compound was administered before, or 30 min after, inhalation of PAF. 5. Pulmonary airway eosinophil accumulation due to inhaled PAF (10 micrograms ml-1) was inhibited by prior treatment with aminophylline, cromoglycate, ketotifen, dexamethasone and AH 21-132. 6. Pulmonary airway eosinophil accumulation due to inhaled PAF (10 micrograms ml-1) was not inhibited by prior treatment with indomethacin, salbutamol or mepyramine.

Aerosols↗
PubMed1990

Ultrasonographic measurement of fetal lung.

Fetal lung measurements were obtained by ultrasonographic examination on 103 normal pregnancies between 18 and 41 weeks' gestation. A linear relationship between right, left and total lung circumference and gestational age was observed. The chest and heart circumference correlated well with gestational age (p less than 0.001). The ratio of left lung circumference to right lung circumference remained virtually constant throughout gestation. However, the ratios of total lung circumference to chest circumference and heart circumference to chest circumference increased significantly (p less than 0.001) with gestational age.

Embryonic and Fetal Development↗