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Biomedical subjects

S Aoki

Publications and source records attributed to S Aoki.

At least 397 records · Page 22Linked to original sources

The neuropeptide, head activator, in human placenta and serum from pregnant women.

The hydra neuropeptide, head activator, was detected in human placenta using radioimmunoassay. The placenta contained 11-68 fmol/g wet weight of head activator. The slope of the inhibition curve by placental extract in radioimmunoassay was identical to that of synthetic head activator. The molecular weight of the major immunoreactive head activator in placental extract corresponded to the synthetic head activator after Bio-Gel P-2 column chromatography. The peak of immunoreactive head activator in the extract emerged at the same retention time as that of the synthetic head activator on reversed-phase high-performance liquid chromatography. Head activator was localized histologically in trophoblasts of placenta by peroxidase-antiperoxidase staining techniques. The head activator staining was inhibited by the excessive synthetic head activator. The serum head activator level during pregnancy ranged from 9 to 31 pmol/l. A positive linear correlation was found between serum head activator content and gestational weeks.

Amino Acid Sequence↗

Copulatory behavior of sexually inexperienced male voles paired with proestrous females.

The copulatory behavior in sexually inexperienced male voles aged 9-13 weeks old was observed under dim red illumination. Proestrous females were used as stimulus voles in copulatory behavior tests. A 30-min test session was recorded. All males showed at least one ejaculation within 30 min. In addition, the pattern of copulatory behavior in male voles was compared to that reported previously in male hamsters. The frequencies of mount, intromission and ejaculation in male voles were similar to that in male hamsters but there were significant differences in the latencies of mounting, intromission, ejaculation and post-ejaculation between the two species.

Animals↗

p-Chloroamphetamine-induced ejaculation and the 22-kHz vocalization of the male rat.

It is well known that the male rats paired with receptive females emit the 22-kHz vocalization after ejaculation. The question addressed is whether after ejaculation injected with PCA without receptive females the 22-kHz call would be emitted. Emission of the 22-kHz call in males injected by PCA was not observed after ejaculation.

Animals↗

Pre- and post-implantation losses of embryos in aging female IVCS mice.

Mated female mice of the IVCS strain, aged 90 (control group), 180, 210, 240, 270, 300, 330, 360 and 420 days old, were studied for pre- and post-implantation loss of embryos. The percentage of pre-implantation loss in mice aged 90 to 210 days was 1.7/11.8 (14.4%) to 2.7/11.7 (23.1%). In mice aged 240 to 300 days it increased significantly as compared to the controls (46.5-90.2% versus 14.4%). It reached 100% in 300-days-old mice. The post-implantation loss of embryos and/or fetuses in mice aged 90 to 240 days was 1.0/10.2 (9.8%) to 2.5/9.0 (27.8%). In mice aged 270 to 300 days it increased significantly compared to the controls (100% versus 9.8%). The decrease in reproductive activity appeared first in a decrease in litter size, followed by a decrease in the number of blastocyst and implantation sites, and finally by anovulation during the process of aging in IVCS mice.

Aging↗

Central effects of yohimbine on copulatory behavior in aged male rats.

It is well known that yohimbine has a history of popular use because of its supposed aphrodisiac properties. The present study was done to determine whether yohimbine can modify the copulatory behavior of aged male rats. Adult male rats of the Wistar-Imamichi strain, 52 weeks of age and weighing 600-650g, were injected intracerebroventricularly with yohimbine hydrochloride (5, 10 micrograms/10 microliters/rat) or vehicle. Each male was then given the opportunity to mate with a receptive female for 30 min after administration of yohimbine or vehicle. Yohimbine produced significant decreases in the latency to initial mounting and significant increases in the number of mountings. However, there was no ejaculation in the yohimbine-and vehicle-treated males. This study is the first to clearly establish an important modulator of sexual arousal for yohimbine in aged male rats.

Aging↗

Effects of methamphetamine on copulatory behavior in male rats.

Many papers have reported the effect of amphetamine and its close relative, methamphetamine on sexual activity in humans. The effect of these drugs on animal sexual behavior is unknown. The present study was done to determine whether methamphetamine modifies the copulatory behavior of male rats. Sexually experienced rats of the Wistar-Imamichi strain, 10 weeks of age, were singly injected intraperitoneally with methamphetamine hydrochloride at doses of 0, 1, 2 or 4 mg/kg body weight. Tests were initiated at 19: 30 in the dark period. Observations were conducted for 90 min. At dosages of 1 or 2 mg/kg there were no changes in copulatory behavior ascribed to the administration of methamphetamine. At 4 mg/kg the frequencies of mounting, intromission and ejaculation were greatly decreased but the spontaneous motor activity and stereotypic behavior increased in all males. In a further experiment, males were given methamphetamine by intraperitoneal injection once a week for 8 weeks. The copulatory behavior was tested 5 times at two weeks intervals. In the 4th testing, the percentage showing ejaculation decreased. In the 5th testing, there was no ejaculation and the incidence of intromission decreased. No stereotypic behavior was displayed in any of the males during the testing. From these results, it was concluded that methamphetamine inhibits the intromitting and ejaculating behavior in male rats.

Animals↗

Ejaculations induced by p-chloroamphetamine (PCA) in rats, hamsters and mice.

The ejaculatory response induced by p-chloroamphetamine (PCA) in male rats, hamsters and mice was observed during 2 hours after the injection. The animals were treated intraperitoneally with PCA at doses ranging from 0.78125 to 160 mg/kg. The ED50 (effective dose in 50% of animals) values of PCA for the initiation of ejaculation in rats and hamsters were 1.3397 (1.0732-1.6725) and 0.1105 (0.0802-0.1522) mg/kg, respectively. On the other hand, no ejaculation was observed in any mice at any doses examined. So we concluded that there are species differences in the ejaculatory response, induced by PCA, among rats, hamsters and mice.

Animals↗

[Comparison of the two different approaches of orchiectomy in guinea pigs].

The results of orchiectomy conducted by the abdominal and scrotum routes were compared in guinea pigs. The operation time, surgical complication and incision healing were evaluated. About operation time, there was no distinct difference between two routes. In the abdominal route, the prognosis of this case was favorable. Also the healing of an incised wound was uneventful one week after the operation. While in the scrotum route, the tunica albuginea testis and the visceral vaginal tunic are thin, so that the risks of injuring the testis and/or scattering the contents of testis seem to be high. Inflammation of the scrotum was observed in 4 out of 5 guinea pigs, that were operated by scrotum route. From these results, the abdominal route method is highly recommended in the orchiectomy of guinea pigs.

Animals↗

Accumulation of tri-n-butyltin chloride and triphenyltin chloride by oral and via gill intake of goldfish (Carassius auratus).

1. The bioconcentration factors (BCF) of both chemicals via gill intake of goldfish reached plateaux after 21 days of exposure. The average BCF values of Bu3SnCl and Ph3SnCl (N = 2) were 1976 and 1384, respectively, after 21-28 days of exposure. 2. The BCF values by oral intake of goldfish reached plateaux after 28 days for Bu3SnCl but did not for Ph3SnCl. The BCF values of Bu3SnCl and Ph3SnCl were 0.04 and 0.10, respectively, after 35 days. 3. The order of the BCF values via gill intake was reversed compared with that by oral intake. Further, the contamination of freshwater fish by these compounds was discussed using the results of these experiments.

Administration, Oral↗

Induction of experimental Candida arthritis in rats.

Experimental arthritis, caused by intravenously (IV) introduced Candida albicans, has been induced for the first time in rats. Four-week-old Sprague-Dawley rats were inoculated IV with three different strains of C. albicans and observed for 4 weeks. Each of the three strains tested was able to produce arthritis. The incidence of Candida arthritis increased in a dose-dependent manner and was more than 90% at sublethal doses. Joints of the limbs were affected predominantly, and at higher doses arthritis was produced in multiple (four or five) joints in individual animals, showing it to be polyarthritis. C. albicans was recovered from all cultures of affected limb joints, which were excised 12, 19 and 28 days after inoculation and showed different stages and degrees of joint swelling. Results of histopathology and radiography showed that the Candida arthritis involved not only periarticular inflammation but also changes in joint bones. In particular, metaphyseal enlargement, punched-out lesions at the diaphysis and the appearance of osteoclasts were the most prominent changes in affected bones. These pathological features are compared with those of Candida arthritis in humans.

Animals↗

[Changes in respiratory resistance and dynamic compliance induced by histamine in the guinea pig].

Respiratory resistance and dynamic compliance in guinea pigs were measured by pulmonary mechanics analyzer Buxco Model 6. Changes induced by intravenous injection of histamine were studied. Administration of histamine caused dose-dependent increase in respiratory resistance and decrease in dynamic compliance in guinea pigs. The increase in respiratory resistance by repeated injections of the same dose of histamine was maintained at the same level 5 hours after the first injection. However, the decrease in dynamic compliance by histamine administration decreased significantly from 1 to 4 hours after the first injection. The baseline resistance increased from 1 to 5 hours after the first injection of histamine. The baseline compliance decreased from 1 to 5 hours after the first injection.

Airway Resistance↗

[Laboratory and clinical studies of cefdinir 5% and 10% fine granules in pediatric field].

We have carried out laboratory and clinical studies on cefdinir (CFDN) 5% and 10% fine granule preparations. The results are summarized as follows. CFDN 5% fine granule preparation was given via oral route to each of 2 children in the fasting state at a single dose of 3 mg/kg. After administration, the mean peak plasma level of CFDN was 0.76 micrograms/ml at 4 hours and the mean half-life was 1.77 hours. The mean urinary excretion rate of CFDN was 31.5% in the first 12 hours after oral administration. CFDN 10% fine granule preparation and CFDN 100 mg capsule were given via oral route 3 children and to another child in the fasting state at single doses of 3 mg/kg and 2.63 mg/kg, respectively. After administration of 10% granules the mean peak plasma level of CFDN was 0.73 micrograms/ml at 2 hours and the mean half-life was 1.62 hours. The peak serum level obtained after administration of CFDN 100 mg capsule was 0.91 micrograms/ml at 2 hours and the half-life was 1.08 hours. The mean urinary excretion rate obtained with CFDN 10% fine granules was 26.2% in the first 8 hours after oral administration and the urinary excretion rate obtained with CFDN 100 mg capsule was 19.7% in the first 12 hours after oral administration. Treatment with CFDN 5% fine granules was made for a total of 48 cases of pediatric bacterial infections including 21 cases of tonsillitis, 12 cases of scarlet fever, 3 cases of pharyngitis, 5 cases of impetigo, 1 case of subcutaneous abscess, 1 case of furuncle, 5 cases of UTI. Results obtained were excellent in 30 cases, good in 18 cases. Treatment with CFDN 10% fine granules was made for a total of 16 cases of pediatric bacterial infections including 6 cases of tonsillitis, 3 cases of pneumonia, 4 cases of scarlet fever, 2 cases of impetigo, 1 case of UTI. Results obtained were excellent in 8 cases, good in 7 cases, poor in 1 case. No significant side effects due to the drugs were observed except 2 cases (1 case with 5% preparation and another with 10%) with eosinophilia, 3 cases (all with 5%) with diarrhea and 1 case each of elevated GOT & GPT (with 5%) and elevated GOT, GPT & Al-P (with 10%).

Administration, Oral↗

[Intermittent administration of natural interferon-alpha for over 5 years induced complete suppression of Philadelphia chromosome in a patient with myelogenous leukemia].

A 60-year-old woman was admitted to our hospital because of gastric ulcer, anemia, and leukocytosis in November 1984. Blood cell counts on admission were as follows: RBC 407 x 10(4)/microliters, Hb 9.8 g/dl, WBC 33,000/microliters (baso 8%, eo 7%, myelo 11%, meta 2%, stab 4%, seg 54%), Plt 93.7 x 10(4)/microliters. Bone marrow showed hypercellular and myeloid hyperplasia. She was diagnosed as Ph1-chromosome positive chronic myelogenous leukemia. She received natural interferon-alpha at the dosage of 600 x 10(4) IU daily for 22 days from January 14, 1985. After March 1985, she has been given intermittent administration of interferon once in 10 to 20 days, and maintained normal blood cell counts. Cytogenetic improvement was seen on 35 months after the start of IFN and complete suppression of Ph1 chromosome was observed at July 1990 (66 months after).

Drug Administration Schedule↗

Evaluation of lining materials and a new concept for lining: alpha-TCP cement or visible light curing calcium hydroxide composition in composite resin restoration.

Histological studies on the effect of lining methods using a alpha-TCP (TC) and a VLC Dycal (LD) were reported previously. In this report, SEM and electron-probe microanalyzer observations were utilized to determine the effects of lining methods. SEM observations were made on longitudinal sections prepared by a freeze fracture method, using 30 vital dog teeth and 5 vital human teeth. In the LD group, several kinds of crystal growth were seen on surfaces of the material and dentinal wall. In the TC group, the exfoliated space area filled up with rod-shaped crystals. An electron-probe microanalyzer was employed to examine the crystal elements observed in the interface or the exfoliated space area. Our findings indicated that lining appeared to fill the gaps with crystal growth, block stimuli which result from bacterial invasion into the dentinal tubules, and reinforce the superficial dentinal zone.

Acid Etching, Dental↗

[Laboratory and clinical studies of cefpirome in pediatric field].

We have carried out laboratory and clinical studies on cefpirome (CPR, HR 810). The results are summarized as follows. CPR was given by 30-minute drip infusion to 3 children at a single dose of 20 mg/kg. After the 30-minute drip infusion, the mean peak serum level of CPR was 65.7 +/- 2.2 micrograms/ml at the end of infusion, and the mean half-life was 1.49 +/- 0.046 hours. The mean urinary excretion rate of CPR was 57.0 +/- 25.8% in the first 8 hours after the 30-minute drip infusion of 20 mg/kg. Treatment with CPR was made in 9 cases of pediatric bacterial infections; 1 case each of tonsillitis, pharyngitis, and bronchopneumonia, 4 cases of pneumonia, 2 cases of urinary tract infection. Results obtained were excellent in 6 cases, good in 3 cases. No significant side effects due to the drug were observed except one case of elevated GOT and GPT, and 3 cases of eosinophilia.

Adolescent↗

[Bronchial hyperresponsiveness to histamine following antigen challenges in actively sensitized guinea pigs].

Guinea pigs were actively sensitized by intraperitoneally administered ovalbumin and challenged by intravenous injections of ovalbumin. Respiratory resistance and dynamic compliance were measured by pulmonary mechanics analyzer Buxco Model 6. Changes in resistance (delta R) and compliance (delta C) induced by intravenously administered histamine were investigated before and after the challenge. Responses to the histamine in sensitized guinea pigs were also compared with those in naive guinea pigs. The following results were obtained. 1) A significant increase in delta R by histamine administration was observed following the antigen challenge. delta C by histamine administration showed a tendency to increase after the challenge. 2) A significant increase of delta R by 7.2 micrograms/kg histamine administration was observed in actively sensitized guinea pigs. However, delta C by the histamine administration did not change in the sensitized animals.

Airway Resistance↗