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Biomedical subjects

Y Yasuda

Publications and source records attributed to Y Yasuda.

At least 163 records · Page 9Linked to original sources
PubMed1995

Development of Babesia gibsoni in the salivary glands of the larval tick, Rhipicephalus sanguineus.

The development of Babesia gibsoni in the salivary glands of larval Rhipicephalus sanguineus ticks was morphologically studied for 4 days of feeding of tick on rabbits. Babesia gibsoni showed two forms (sporont and sporozoite) in the budding process. Sporozoites were formed in the acinar cells of salivary glands and released from the hollow cytoplasmic area of these cells by day 4 of feeding. The morphology of B. gibsoni in the salivary glands of R. sanguineus shows a close similarity to those of B. gibsoni in Haemaphysalis longicornis.

Animals↗
PubMed1995

Effects of the neonatal vitamin A exposure on behaviors of adult rats.

The effects of neonatal vitamin A exposure on six behavioral parameters in adult Wistar rats were investigated. Newborn male rats were injected intraperitoneally with 80,000 IU/kg/day of retinol palmitate (vitamin A) dissolved in physiological saline or vehicle alone (controls) during 1-5 days after birth. The animals were examined using the open field test (at 36 weeks of age), the rotarod test (38 weeks), the Biel water-maze test (40 weeks), the conditioned avoidance test (42 weeks), the running-wheel activity with pentobarbital challenge test (44 weeks), and the tail flick test (45 weeks). The vitamin A-exposed rats made significantly more errors and took significantly longer times in the Biel water-maze test, and showed significantly slower responses in the tail flick test than the controls. No significant effects of treatment with vitamin A were observed in any of the other behavioral tests. These results indicate that a long-lasting defect in learning in water-maze task and depression of the heat-pain response are induced in rats exposed neonatally to vitamin A.

Animals↗
PubMed1995

Salfredins, new aldose reductase inhibitors produced by Crucibulum sp. RF-3817. I. Fermentation, isolation and structures of salfredins.

New inhibitors of aldose reductase, designated salfredins A3, A4, A7, C1, C2, C3 and B11, were isolated from the fermentation broth of Crucibulum sp. RF-3817 by successive purification procedures of solvent extraction, silica gel column chromatographies and reverse-phase HPLC. Their structures were established by spectroscopic methods, including UV, SI-MS and NMR. The structures of salfredins A4 and B11 were confirmed by X-ray crystallographic analysis.

Aldehyde Reductase↗
PubMed1995

[The result of reoperation for lung cancer].

Twenty four patients with recurrent or multiple lung cancer were reoperated in our center. Five-year survival rate was 20% for 11 patients with recurrent, while was 25% for 13 patients with multiple after reoperation. The patients with limited operation had well survival and there was no significant difference in procedure. However all four patients with N2 had poor prognosis. Seven patients (29%) had the post reoperative complication in pulmonary system. All of them had the impairment of pulmonary function (FEV1.0% was less than 50%) or more than 75% perfusion ratio, measured with pulmonary perfusion scintigraphy, in the side of the reoperation.

Adenocarcinoma↗
PubMed1995

[Positive expression of c-myc and p53 products in two cases of pulmonary sclerosing hemangioma].

The c-myc and p53 genes are thought to be an oncogene and a tumor suppressor gene, respectively. These genes' products are characteristic of malignant tumors. We quantitatively analyzed the c-myc and p53 products by flow cytometry in two cases of pulmonary sclerosing hemangioma. In case 1, 32.3% of the tumor cells were found to have the c-myc product, and 8.9% were found to have the p53 product. In case 2, 6.7% of the tumor cells were found to have the c-myc product and 15.5% were found to have the p53 product. The percentages in both cases were twice as high as those in a negative control lymphocytes stained with c-myc and p53 products. Therefore, these two cases showed positive expression of the c-myc and p53 products. In addition DNA from six other patients with sclerosing hemangioma was analyzed with paraffin-embedded sections. All six had DNA diploidy, with DNA indexes ranging from 0.91 to 1.03 and coefficients of variation ranging from 3.0 to 5.5. We suggest that pulmonary sclerosing hemangioma is a very weakly malignant tumor.

Adult↗
PubMed1994

Production of germline chimeric chickens, with high transmission rate of donor-derived gametes, produced by transfer of primordial germ cells.

Germline chimeric chickens were produced by transfer of primordial germ cells from White Leghorn to Barred Plymouth Rock, and vice versa. Blood was collected from stage 13-15 embryos and primordial germ cells were concentrated by Ficoll density gradient centrifugation. Approximately 200 primordial germ cells were injected into the bloodstream through the dorsal aorta of stage 14-15 recipient embryos from which blood had been drawn via the dorsal aorta prior to the injection. Intact embryos were also prepared as recipients for White Leghorns only. The manipulated embryos were cultured in recipient eggshells until hatching. Germline chimerism of the chickens reaching maturity was examined by mating them with Barred Plymouth Rocks and donor-derived offspring were identified based on their feather color. The efficiency of production of germline chimeras was 95% (19/20). When primordial germ cells were transferred from White Leghorn to Barred Plymouth Rock, the average frequency of donor-derived offspring was 81% for three male chimeras (96% for one female chimera), and it was approximately 3.5 times higher for transfer in the opposite direction (23% for 6 male chimeras). Removing blood from recipient embryos prior to primordial germ cell injection enhanced the frequency of donor-derived offspring by 10% in resulting male chimeras. Male chimeras produced donor-derived offspring more frequently (approximately 3.8 times) than female chimeras. Increases, decreases, or no changes were observed in the frequency of donor-derived offspring from the germline chimeras with increasing age.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Characterization of crustacean hyperglycemic hormone from the crayfish (Procambarus clarkii): multiplicity of molecular forms by stereoinversion and diverse functions.

The complete amino acid sequence of two forms of crustacean hyperglycemic hormone (CHH) from the X-organ sinus gland complex of crayfish (Procambarus clarkii) has been determined. There are two variants of P. clarkii CHH (Prc-CHH), I and II, which can be separated by reversed-phase high-performance liquid chromatography (RP-HPLC). Each variant was oxidized by performic acid and then cleaved with lysyl endopeptidase. Intact hormone was also digested with trypsin and endoproteinase Asp-N, successively. The resulting fragments were separated by RP-HPLC and subjected to sequence analyses by a gas-phase sequencer and tandem mass spectrometry. Both variants contain 72 amino acid residues with three disulfide linkages, at positions 7-43, 23-39, and 26-52, and differ from each other by the D/L epimerization of phenylalanine at position 3; Prc-CHH-II contains D-amino acid. Injections of Prc-CHH-I and Prc-CHH-II at a dose of 12.5 pmol resulted in significant increase of hemolymph glucose levels in the crayfish. The hormones are also active in repressing ecdysteroid synthesis at concentrations of 250 mM (Prc-CHH-I) and 25 nM (Prc-CHH-II) in Y-organ culture. These results may indicate that the stereoinversion in the CHH molecule leads to an important alternation in hormonal functions during crustacean development.

Amino Acid Sequence↗
PubMed1994

Neuromuscular fatigue during prolonged pedalling exercise at different pedalling rates.

The purpose of this study was to estimate the differences in neuromuscular fatigue among prolonged pedalling exercises performed at different pedalling rates at a given exercise intensity. The integrated electromyogram (iEMG) slope defined by the changes in iEMG as a function of time during exercise was adopted as the measurement for estimating neuromuscular fatigue. The results of this experiment showed that the relationship between pedalling rate and the means of the iEMG slopes for eight subjects was a quadratic curve and the mean value at 70 rpm [1.56 (SD 0.65) microV.min-1] was significantly smaller (P < 0.01) than that at 50 and 60 rpm [2.25 (SD 0.54), and 2.22 (SD 0.68), respectively]. On the other hand, the mean value of oxygen consumption obtained simultaneously showed a tendency to increase linearly with the increase in pedalling rate, and the values at 70 and 80 rpm were significantly higher than those at 40 and 50 rpm. In conclusion, it was demonstrated that the degree of neuromuscular fatigue estimated by the iEMG changes for five periods of prolonged pedalling exercise at a given exercise intensity was different among the different pedalling rates, and that the pedalling rate at which minimal neuromuscular fatigue was obtained was not coincident with the rate at which the minimal oxygen consumption was obtained, but was coincident with the rate which most subjects preferred. These findings would suggest that the reason why most people prefer a relative higher pedalling rate, even though higher oxygen consumption is required, is closely related to the development of neuromuscular fatigue in the working muscles.

Adult↗
PubMed1994

Cheiro-oral-pedal syndrome in the lesion of thalamocortical projections.

Unilateral sensory disturbance in the hand and mouth (cheiro-oral syndrome) is well known, but one in the hand, mouth and foot region (cheiro-oral-pedal syndrome) has been reported only in 2 patients with brainstem lesion and in 2 patients with thalamic infarction. We report the first case of cheiro-oral-pedal syndrome due to involvement of thalamocortical projections, which favors somatotopy in thalamocortical projections.

Brain Mapping↗
PubMed1994

The prevalence of cardinal TMJ dysfunction symptoms and its relationship to occlusal factors in Japanese female adolescents.

Cross-sectional data were obtained from 1182 Japanese high school girls of 12 and 15 years old. The data were analysed for the prevalence of specific occlusal features and the prevalence of cardinal Temporomandibular Joint Dysfunction (TMJD) symptoms in different occlusion groups. The associations between occlusal features and TMJD symptoms were analysed by the Z-analysis. The results were as follows: the prevalence of TMJD symptoms (total) was about 23% in both age groups examined. Noise had the highest prevalence of the specific TMJD symptoms in both age groups (16% and 11%). With age and for different occlusion groups, there was a significant increase in deviation on opening (P < 0.001) and a decrease in pain and noise (P < 0.05). No significant associations were found between the occurrence of TMJD symptoms (total) and occlusal features in all the examined occlusion groups. With respect to specific TMJD symptoms, however, the investigation of the different groups revealed a significant association (P < 0.05) of intra-arch occlusal (crowding) features with the occurrence of deviation on opening and with the occurrence of the combined TMJD symptoms which include deviation on opening. This indicates that crowding may be an important sign for predisposing TMJD. For the other single disorder symptoms (except pain), we did not find a significant relationship (P < 0.05) with aspects of occlusion, which may confirm a multifactorial TMJD problem wherein occlusal features can have a contribution to TMJD.

Adolescent↗
PubMed1994

Development of Babesia ovata in the salivary glands of the nymphal tick, Haemaphysalis longicornis.

The development of Babesia ovata in the salivary glands of nymphal Haemaphysalis longicornis ticks was morphologically studied for 4 days of feeding of tick on rabbits. Babesia ovata showed two forms (sporont and sporozoite) in the budding process. Sporozoites were formed in the acinar cells of salivary glands and released from the hollow cytoplasmic area of these cells by day 4 of feeding.

Animals↗
PubMed1994

Preservation of chick primordial germ cells in liquid nitrogen and subsequent production of viable offspring.

Conservation of genetic material in chickens was attempted by preserving primordial germ cells in liquid nitrogen. Primordial germ cells collected from the blood of embryos at stage 13-15 of White Leghorn and Barred Plymouth Rock breeds were concentrated by Ficoll density gradient centrifugation. The primordial germ cells were then suspended in a freezing medium containing 10% dimethyl sulfoxide. The temperature of the cell suspension was decreased by 1 degree C min-1 to -80 degrees C; the suspension was then placed in liquid nitrogen (-196 degrees C) and stored for 4-5 months. The cell suspension was thawed by taking it out of liquid nitrogen and placing it in water at 4 degrees C. The viability of the frozen-thawed primordial germ cells was 94.2%. One hundred frozen-thawed cells were injected into the bloodstream of recipient embryos (stage 14-15) from the other breed, from which blood had been drawn before the injection. These embryos were cultured in recipient eggshells until hatching. Viable offspring derived from the frozen-thawed primordial germ cells were obtained by mating male and female germline chimaeras or by mating the chimaeras with Barred Plymouth Rock chickens, and the offspring showed normal reproductive performance. This technique for cryopreservation of primordial germ cells giving rise to viable offspring makes it possible to conserve genetic material in avian species.

Animals↗
PubMed1994

Effect of exercise intensity on the spectral properties of skin blood flow.

The effect of exercise intensity on the power spectral properties of the periodic oscillation of the skin blood flow was investigated with respect to the variability of heart rate in 7 healthy male subjects. The skin blood flow (SBF) and heart rate (HR) were measured by a laser-Doppler flowmeter on the forehead skin, and by an ECG, at rest and during bicycle exercise in three different intensities; unloaded, 50 and 100 W. An alcohol ingestion test was additionally performed on two subjects in the resting condition. Power spectral density (PSD) was calculated by means of fast Fourier transform (FFT). The peak frequency (PF) and integration of PSD (iPSD) of each component was estimated to compare conditions and parameters. In the SBF fluctuation, two major components were usually observed: one synchronous with cardiac contraction rhythm (HFF) which shifted to a higher frequency band with exercise; the other was located in a lower frequency band (LFF) ranging from about 0.1 to 0.2 Hz and did not shift with exercise. The PF of the LFF in the SBF was significantly different from that of the HR, called Mayer waves. The iPSD of the LFF in the SBF increased with increasing intensity of exercise but finally decreased at the highest intensity for which the HFF exhibited a marked increase. The LFF in the SBF disappeared after oral ingestion of alcohol that induced an increase of the SBF. From these spectral analyses, it is proposed that the LFF in the SBF is mainly related to the vasoconstrictor activity through the skin sympathetic pathway, and that the intensity of exercise does not modulate the periodicity of this fluctuation.

Adult↗
PubMed1994

[The effect of calcitonin gene-related peptide on the hepatic hemodynamics after releasing of hepatic ischemia].

The effect of synthetic chicken calcitonin gene-related peptide (CGRP) on the hepatic circulation was studied using adult mogrel dogs. Infusion of CGRP (10(-9) M/kg) decreased the mean arterial blood pressure to 56.8% of the pre-infusion value and increased heart rates to 106.3%. 10(-10) M/kg CGRP increased blood flow of the superior mesenteric artery, hepatic artery and portal vein by 130.1%, 130.2%, and 121.2% respectively of the basal levels. The hepatic blood flow was discontinued for 20 minutes by clamping the hepato-duodenal ligament. After reestablishing effects of CGRP on the hepatic hemodynamics became more evident. These results offer the possibility that CGRP may be used to maintain the hepatic blood flow stable during and after hepatic surgery.

Animals↗
PubMed1994

[A case of intractable pulmonary tuberculosis complicated by idiopathic thrombocytopenic purpura (ITP)].

The authors describe a case of pulmonary tuberculosis with multiple drug resistance and complicated by severe idiopathic thrombocytopenic purpura (ITP). The patient was initially treated with high-dose gamma globulin therapy and splenectomy. These procedures resulted in improvement of the patient's condition; the platelet count increased from 7,000/mm3 to 230,000/mm3 and the bleeding time fell from 15 min to 1 min 30 s. Given the significant improvement in the patient's condition, it was considered safe to carry out left pulmonary upper lobectomy and thoracoplasty. There have been no reports describing pulmonary resection performed for inflammatory lung disease in patients with ITP. High-dose gamma globulin therapy rapidly brings about an increase in the platelet count and a reduction of the bleeding time, and it thus extremely useful as preoperative treatment in surgical cases complicated by thrombocytopenia.

Humans↗