Biomedical subjects

T Miyoshi

Publications and source records attributed to T Miyoshi.

At least 37 records · Page 2Linked to original sources

PubMed2004

Hypernuclear fine structure in (16)(Lambda)O and the LambdaN tensor interaction.

We have observed two gamma-ray transitions in (16)(Lambda)O from the 6.6 MeV excited 1(-)(2) state to both ground-state spin-doublet members (1(-)(1),0(-)) by the (K-,pi(-)gamma) reaction. We have obtained the ground-state doublet spacing to be 26.4+/-1.6(stat)+/-0.5(syst) keV and the excitation energy of the 1(-)(2) state to be 6561.7+/-1.1(stat)+/-1.7(syst) keV. The ground-state doublet spacing provides a small but nonzero strength of the tensor interaction between a Lambda and a nucleon. This is the first experimental result on the LambdaN tensor interaction.

Journal Article↗

PubMed2004

Betulinic acid augments the inhibitory effects of vincristine on growth and lung metastasis of B16F10 melanoma cells in mice.

We examined the antitumour effect of a combination of betulinic acid (BA) and vincristine (VCR) on murine melanoma B16F10 cells in vitro and in vivo. Betulinic acid, a pentacyclic triterpene, showed a synergistic cytotoxic effect on melanoma cells by combinational use of VCR. Betulinic acid and VCR induced cell cycle arrest at different points (BA at G1 phase and VCR at G2/M phase) and caused apoptosis in B16F10 melanoma cells. In the in vivo study, VCR inhibited metastasis of tumour cells to the lung. The addition of BA to VCR augmented suppression of the experimental lung metastasis of melanoma cells in C57BL/6 mice. The number of lung nodules of more than 1 mm in diameter in mice treated with BA and VCR was less than that in mice treated with VCR alone. These results suggest that BA is an effective supplement for enhancing the chemotherapeutic effect on malignant melanoma.

Animals↗

PubMed2004

Effect of cabergoline treatment on Cushing's disease caused by aberrant adrenocorticotropin-secreting macroadenoma.

The present case involves a 47-yr-old woman with Cushing's disease due to pituitary macroadenoma. The patient had suffered from hypertension and obesity for two yr. Her serum cortisol levels were moderately elevated throughout the observation period, and dexamethasone failed to suppress the cortisol secretion. Plasma ACTH levels were markedly high (>100 pg/ml) and did not respond to CRH provocation. Gel filtration analysis of the patient's plasma detected the existence of big ACTH molecules, which eluted with a peak of authentic 1-39 ACTH. Cranial magnetic resonance imaging (MRI) revealed a 3 cm pituitary tumor occupying the sellar region and right cavernous sinus with diffuse enhancement by gadolinium. The pituitary mass was removed by transsphenoidal surgery, and was pathologically identified as compatible to ACTH-producing pituitary adenoma by immunohistochemistry. RT-PCR analysis of total cellular RNA extracted from the resected adenoma revealed a relatively high expression level of dopamine D2 receptor (D2R) mRNA. Therefore, a long-acting D2R agonist, cabergoline (0.25 to 0.5 mg/week), was administered for the remnant adenoma, which gradually reduced ACTH levels in 90 days. In addition, cranial MRI exhibited shrinkage of the remnant pituitary mass after a 6-month treatment with cabergoline. This case demonstrates the efficacy of cabergoline to treat Cushing's disease caused by pituitary macroadenoma secreting aberrant ACTH molecules.

Adenoma↗

PubMed2003

High resolution spectroscopy of the 12Lambda B hypernucleus produced by the (e,e'K+) reaction.

High-energy, cw electron beams at new accelerator facilities allow electromagnetic production and precision study of hypernuclear structure, and we report here on the first experiment demonstrating the potential of the (e,e'K+) reaction for hypernuclear spectroscopy. This experiment is also the first to take advantage of the enhanced virtual photon flux available when electrons are scattered at approximately zero degrees. The observed energy resolution was found to be approximately 900 keV for the (12)(Lambda)B spectrum, and is substantially better than any previous hypernuclear experiment using magnetic spectrometers. The positions of the major excitations are found to be in agreement with a theoretical prediction and with a previous binding energy measurement, but additional structure is also observed in the core excited region, underlining the future promise of this technique.

Journal Article↗

PubMed2003

Angiotensin-converting enzyme inhibitor withdrawal and ACE gene polymorphism.

AIMS: Withdrawal of angiotensin-converting enzyme (ACE) inhibitors may affect the progression of chronic renal failure and an insertion/deletion (I/D) polymorphism of the ACE gene may influence it. METHODS: We retrospectively collected patients with chronic glomerulonephritis and benign nephrosclerosis who discontinued ACE inhibitor use. The relationship between the decline of renal function after the withdrawal and the influencing factors such as ACE gene polymorphism, blood pressure and proteinuria were evaluated using multiple regression analysis. RESULTS: Forty-two patients (initial serum creatinine 0.5 - 6.5 mg/dl) had been treated and discontinued ACE inhibitor use. Only patients with the II or DI genotypes of the ACE gene developed the deterioration of renal function, starting at 2 months after the withdrawal. Stepwise regression analysis revealed that the level of proteinuria after the withdrawal, presence of the insertion of ACE gene and serum creatinine level at the time of withdrawal mainly influenced the decline of renal function after the withdrawal (adjusted R2 = 0.48). CONCLUSION: Withdrawal of ACE inhibitor causes the deterioration of renal function in patients with the II or DI genotypes, high proteinuria after the withdrawal, and high serum creatinine level at the withdrawal, which probably causes the rebound increase in serum ACE activity.

Aged↗

PubMed2003

[Prognosis for the cases after resection of pulmonary metastasis of osteosarcoma].

Osteosarcoma commonly metastasize to the lungs. Sixty-six cases with surgical treatment for pulmonary metastasis of osteosarcomas have been experienced for past 25 years in our hospital. Disease free interval (DFI) and the number of metastatic lesions were assessed in relation to their prognosis. As a result of our assessment, fewer metastasis (3 or less), and longer DFI (1 year or more) had relations to longer post-thoracotomy survival. And the relations between the number of metastatic lesions and DFI were found. Fewer metastasis were associated with longer DFI, and multiple metastasis were associated with short DFI. The cases with fewer metastasis (3 or less) and longer DFI (1 year or more) might have a survival advantage.

Adolescent↗

PubMed2002

Transcriptional suppression of the estrogen receptor by truncated estrogen receptor-alpha.

The estrogen receptor (ER) is composed of six major functional domains - the A/B domain as the activation function 1 domain, domain C as the DNA-binding domain, domain D as a hinge domain, and domain E/F as the ligand-dependent transcriptional domains. A novel protein (designated as SRB-RGS) that interacted with domains C and D of ER alpha (ER alpha C/D) repressed the transcriptional activity of ER alpha. In this study, we have examined whether ER alpha C/D releases transcriptional suppression of ER alpha by intrinsic SRB-RGS. The expression vector of ER alpha C/D was transfected to the human cancer cell, KPL-1, which expressed the intrinsic ER. Unexpectedly, transcriptional suppression of ER by ER alpha C/D was observed. COS-7 cells, which have no intrinsic ER, showed a similar suppression of ER alpha by co-transfection of ER alpha and ER alpha C/D. The DNA-binding and the estrogen-binding activities of ER alpha decreased on co-transfection of ER alpha C/D, suggesting a decrease in the receptor protein itself. It is likely that the degradation of ER by co-transfection caused the transcriptional suppression of the ER.

Animals↗

PubMed2002

Somatosensory graviception inhibits the soleus H-reflexin standing man - an underwater experiment-.

H-reflexes were elicited in the soleus muscle in subjects standing on a force platform in a water tank, under different loading conditions at the ankle joint. The joint loading was altered by changing the combination of buoys and weights attached to lower limb segments, while the total body mass was kept the same. The results revealed that as the joint load was reduced the H-reflex was significantly enhanced as compared to that under the control condition, while it decreased as the joint load was increased, despite the same background EMG activity level. It was demonstrated that the augmented load information from the lower limb joints has an inhibitory effect on the soleus H-reflex, suggesting that this might be one of underlying neural mechanisms responsible for the suppression of H-reflex during human upright standing.

Comparative Study↗

PubMed2001

Wolbachia-mediated parthenogenesis in the predatory thrips Franklinothrips vespiformis (Thysanoptera: Insecta).

Wolbachia are bacterial endosymbionts in arthropods and filarial nematodes. They cause thelytoky, which is a form of parthenogenesis in which females produce females without males, in hymenopteran insects. Infection of this parthenogenesis-inducing Wolbachia has been restricted to the order Hymenoptera, but was found in another insect order, Thysanoptera. A parthenogenetic colony of a predatory thrips Franklinothrips vespiformis (Aeolothripidae) possessed B-group Wolbachia. Male progeny were produced from this thrips by heat and tetracycline treatments. Males produced motile sperm, which were transferred to the female spermatheca by mating. However, the mating did not affect the sex ratios of the next generation, suggesting that the sperm do not fertilize the eggs.

Animals↗

PubMed2001

Measurement of the B(e2) of (7)(lambda)Li and shrinkage of the hypernuclear size.

We report on the first measurement of a hypernuclear gamma-transition probability. gamma rays emitted in the E2(5/2(+)-->1/2(+)) transition of (7)(Lambda)Li were detected by a large-acceptance germanium detector array (Hyperball), and the lifetime of the parent state ( 5/2(+)) was determined by the Doppler shift attenuation method. The obtained result, 5.8(+0.9)(-0.7)+/-0.7 ps, was then converted into the reduced transition probability [ B(E2)] to be B(E2;5/2(+)-->1/2(+)) = 3.6+/-0.5(+0.5)(-0.4) e(2) fm(4). Compared with the B(E2) of the corresponding E2(3(+)-->1(+)) transition in the 6Li nucleus, our result gives evidence that the size of the 6Li core in (7)(Lambda)Li is smaller than the 6Li nucleus in the free space.

Journal Article↗

PubMed2001

Activation of matrix metalloproteinase-2 is correlated with invasiveness in thymic epithelial tumors.

UNLABELLED: BACKGROUND AND OBJECTS: Matrix degradation, which is a critical event in the process of tumor invasion and metastasis, is considered to be caused by the action of proteolytic enzymes. METHODS: We examined the gelatinolytic activity of matrix metalloproteinase (MMP)-9, and the activity of active and inactive forms of MMP-2 in five thymi, five noninvasive thymomas, eight invasive thymomas, and five thymic carcinomas by quantitative gelatinolytic zymography. RESULTS: The gelatinolytic activity of active MMP-2 in five thymi was zero. The mean gelatinolytic activity of active MMP-2 was 0.020 +/- 0.015 in noninvasive thymoma, 0.084 +/- 0.098 in invasive thymoma and 0.246 +/- 0.194 in thymic carcinoma. The gelatinolytic activity of active MMP-2 correlated with the invasiveness of thymic epithelial tumors (Spearman rank correlation: r-value = 0.532). The gelatinolytic activity of active MMP-2 in three thymoma cases with microscopic capsular invasion was the same as that of noninvasive thymoma. When thymoma cases showing microscopic capsular invasion were classified into the "macroscopically noninvasive thymoma" group, the gelatinolytic activity of active MMP-2 correlated with the invasiveness of thymic epithelial tumors (Spearman rank correlation: r-value = 0.621). CONCLUSIONS: The gelatinolytic activity of active MMP-2 significantly correlated with the invasiveness in thymic epithelial tumors. J. Surg. Oncol. 2001;76:169-175.

Enzyme Activation↗

PubMed2001

Multilocular thymic cyst associated with Sjögren's syndrome.

A 61-year-old woman, who had been diagnosed as having Sjögren's syndrome, developed an anterior mediastinal mass. She was diagnosed with Sjögren's syndrome with thymoma, preoperatively. Extended thymectomy was performed. Macroscopically, the mediastinal mass showed thick-walled multiloculated cavities filled with turbid yellow fluid. Microscopically, the cyst lining was continuous with thymic lobules in the wall with inflammatory process, cholesterol granuloma formation, and prominent lymph follicular hyperplasia. She was diagnosed with multilocular thymic cysts associated with Sjögren's syndrome.

Female↗

PubMed2001

Wolbachia infection shared among planthoppers (Homoptera: Delphacidae) and their endoparasite (Strepsiptera: Elenchidae): a probable case of interspecies transmission.

Wolbachia, a group of parasitic bacteria of arthropods, are believed to be horizontally transmitted among arthropod taxa. We present a new probable example of interspecies horizontal transmission of Wolbachia by way of an endoparasite based on the conformity of Wolbachia gene sequences. Field samples of two rice planthoppers, Laodelphax striatellus and Sogatella furcifera possessed identical Wolbachia. Among three major endoparasites of planthoppers, a strepsipteran, Elenchus japonicus, harboured the identical Wolbachia strain, suggesting strepsipteran transmission of Wolbachia from one planthopper to the other. No Wolbachia was detected in a mermithid nematode Agamermis unka, and dryinid wasps possessed different types of Wolbachia.

Animals↗

PubMed2001

Interleukin-8 concentrations in conjunctival epithelium brush cytology samples correlate with neutrophil, eosinophil infiltration, and corneal damage.

PURPOSE: To evaluate whether interleukin-8 (IL-8) and RANTES (regulated on activation, normal T-cell expressed and secreted) concentrations in the supernatants of conjunctival epithelial samples from patients with vernal keratoconjunctivitis (VKC) correlate with the number of infiltrating eosinophils or neutrophils and with the severity of corneal lesions. METHODS: Thirty-four patients with VKC, 5 patients with seasonal allergic conjunctivitis, and 10 volunteers without allergic diseases were enrolled in this study. Conjunctival epithelial cells were collected by brush cytology and the number of inflammatory cells was counted. The chemokine expression in the cells was investigated by immunocytochemistry and the chemokine concentrations of the cell suspensions were measured by enzyme-linked immunosorbent assay. RESULTS: The percentages of eosinophils and neutrophils in cell suspensions from VKC patients with corneal erosion or ulcer were higher than those from subjects with clear corneas or superficial punctate keratopathy. IL-8 concentrations in the supernatant of samples correlated significantly with the percentages of neutrophils and eosinophils in paired cell suspensions. No correlation was observed between RANTES and the percentages of eosinophils. Positive staining for IL-8 was observed in the cytosol of conjunctival epithelial cells. CONCLUSION: IL-8 in the extracellular space of the conjunctival epithelium may play a role in the recruitment of neutrophils and possibly eosinophils and in the pathogenesis of corneal damage in severe allergic diseases.

Adolescent↗

PubMed2001

[The process of the ego identity formation in late adolescence from the viewpoint of the individual-group conflict].

The purpose of this study was to examine the internal process of identity formation in late adolescence in relation to the psychosocial identity crisis from the viewpoint of the individual-group conflict. Subjects (252 university students) were classified into one of three types, depending on two phases of the individual-group conflict: (a) whether or not the conflict has been experienced; and (b) if so, whether or not the conflict had already been solved. The traits of each type were subsequently determined by examining the individual's awareness of their relationship with the group and their sense of identity. The main results were as follows: (a) The experiencing of the individual-group conflict was closely related to the unsettling of the sense of identity. (b) Men tended to resolve the individual-group conflict by detaching themselves from the group and defining a personal sense of identity. (c) In women, at least two means of resolving the conflict were found. One of these means was similar to means used by men, while the other means was that of immersing themselves further into the group.

Adolescent↗

PubMed2001

Suppression of mediastinal metastasis by uracil-tegafur or cis-diamminedichloroplatinum(II) using a lymphogenous metastatic model in a human lung cancer cell line.

PURPOSE AND EXPERIMENTAL DESIGN: The extent of lymphatic metastasis is the most important factor in the prognosis for non-small cell lung cancer (NSCLC). Therefore, suppression of lymphatic metastasis provides an improvement in survival time in lung cancer patients. We established a new patient-like model for lung cancer metastasis by orthotopic implantation in severe combined immunodeficiency (SCID) mice and demonstrated the lymphogenous spread histologically using human NSCLC cell lines. The cardinal features of this model are a simple procedure and a similarity to the metastatic form of human lung cancer. The purpose of this study is to assess the inhibitory action of uracil-tegafur (UFT) and cis-diamminedichloroplatinum(II) (CDDP) on lymphatic metastasis and life span prolongation in our lymphogenous metastatic model system using SCID mice. RESULTS: The inhibition ratios of mediastinal lymph node metastasis were 86.2, 94, and 92.1% for 12 mg/kg body UFT, 17 mg/kg body UFT, and 10 mg/kg body CDDP, respectively. The administration of anticancer drugs prolonged the life span by 4.6 days (17 mg/kg body UFT) and 8 days (10 mg/kg body CDDP) in MST. CONCLUSION: We demonstrated that UFT alone and CDDP alone suppressed mediastinal metastasis and prolonged the life span in our lymphogenous metastatic model. Regardless of the administration route and characteristics of anticancer drugs, cytostatic or cytotoxic, our model is capable of evaluating the inhibitory effect of drugs on lymphatic metastasis. This model should make an important contribution to our understanding of the mechanism and selection of drugs for antilymphatic metastasis in lung cancer.

Animals↗

PubMed2001

Effect of long-term bedrest on lower leg muscle activation patterns during quiet standing.

It has been well known that balance instabilities after long-term exposure to microgravity (e.g., Anderson et al. 1986) or bedrest (BR) can be related to alterations and/or adaptations to postural control strategies. Little is known, however, how the reduced muscular activity affects the activation pattern of the lower limb muscles during quiet standing (QS). The purpose of this study was to investigate whether or not any changes in the lower limb muscle activation patterns during QS would occur after BR.

Adult↗

PubMed2001

Reflex response changes during hyper and microgravity.

This paper reports the quantitative evaluation of the H-reflex exhibited by parabolic flight with exposure to micro and high-gravity. With respect to previous findings in parabolic flights and short-term space missions, the analysis focused on reflex activity in weightlessness. The aim of this study was to investigate the effect of gravity on H-reflex and motor evoked potentials (MEP) in soleus muscle (SOL) during parabolic flight.

Adult↗