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Biomedical subjects

Y Ishida

Publications and source records attributed to Y Ishida.

At least 19 recordsLinked to original sources
PubMed2006

Benign variations and incidental abnormalities of myocardial FDG uptake in the fasting state as encountered during routine oncology positron emission tomography studies.

Increased 18fluoro-2-deoxyglucose (FDG) uptake in the myocardium is frequently observed while performing clinical positron emission tomography (PET) body scans for oncology under fasting conditions. This article reviews the normal variations and abnormal appearances of myocardial FDG accumulation which are likely to be encountered in the routine PET studies. Knowledge about the myocardial glucose metabolism and specific abnormalities are indispensable in the interpretation of myocardial FDG uptake.

Fasting↗
PubMed2006

Differential effects of prenatal stress on the morphological maturation of hippocampal neurons.

The present study was designed to clarify an intensity-dependent effect of prenatal stress on the morphological development of hippocampal neurons in rats. In addition, the involvement of receptors for glucocorticoids, i.e. mineralocorticoid receptors and glucocorticoid receptors, in stress-induced changes in the morphology of hippocampal neurons was examined by an in vitro pharmacological approach. The effects of mild prenatal stress on neurogenesis and long-term potentiation in the hippocampus were also investigated in adult offspring. Prenatal stress affected the morphological development of the hippocampus in an intensity-dependent manner. Short-lasting, mild prenatal stress enhanced neonatal neurogenesis and differentiation of processes of hippocampal neurons, whereas long-lasting, severe stress impaired their morphology. Mineralocorticoid receptor was found to mediate enhancement of neurogenesis and differentiation of processes of cultured hippocampal neurons. In contrast, glucocorticoid receptor was involved in the suppression of their morphology. Short-lasting, mild prenatal stress, which has previously been shown to enhance learning performance in adult offspring, facilitated neurogenesis and long-term potentiation in the adult hippocampus. These findings suggest that prenatal stress has enhancing and suppressing effects on the development of hippocampal neurons depending on intensity, and that mineralocorticoid receptors and glucocorticoid receptors contribute to stress-induced morphological changes.

Animals↗
PubMed2006

Do motorcyclists have erectile dysfunction? A preliminary study.

The aim of the present study was to evaluate the relationship between motorcycling and erectile dysfunction (ED). We investigated the relationship between motorcycling and erectile function using the 5-items version of the International Index of Erectile Function (IIEF5) in 234 motorcyclists (response rate 75%) and 752 healthy controls (response rate 66%). In all, 161 (69%) of 234 motorcyclists were diagnosed as ED based on IIEF5. The prevalence of ED in the motorcycle group increased by age as: 58, 63, 76 and 93%, for motorcyclists in 20-29, 30-39, 40-49 and 50-59 years, respectively. There was a significant difference in the prevalence of ED between the motorcycle group and the control group in all age groups. On stepwise logistic regression analysis, motorcycling was the strongest risk factor for ED. Although the severity of ED in motorcyclists was not so severe, motorcycling may be one of risk factors for ED.

Adult↗
PubMed2006

JTP-426467 acts as a selective antagonist for peroxisome proliferator-activated receptor gamma in vitro and in vivo.

AIM: JTP-426467 was identified as a result of screening in search of selective antagonist for peroxisome proliferator-activated receptor gamma (PPARgamma). We examined whether JTP-426467 functioned as a PPARgamma antagonist in vitro and in vivo and investigated physiological effects of JTP-426467. METHODS: The effect of JTP-426467 as a PPARgamma antagonist was studied in a cell-based reporter assay and an adipocyte differentiation assay. Target mRNA expression levels were determined by branched DNA (bDNA) assay. To examine the effects as a PPARgamma antagonist in vivo, a competitive study between JTP-426467 and BRL49653 (rosiglitazone), a PPARgamma agonist, was performed using KK-Ay mice. The effects of JTP-426467 alone after administration to KK-Ay mice were also explored. JTP-426467 antagonized PPARgamma activity in a reporter assay system, but not PPARalpha. RESULTS: JTP-426467 inhibited the expression of hormone-sensitive lipase (HSL) mRNA, an adipocyte-abundant gene, but not PPARgamma itself or cyclophilin mRNA (as constitutive mRNA), and also suppressed triglyceride accumulation in differentiated stromal vascular fraction cells (SVFs). JTP-426467 antagonized PPARgamma agonistic action by BRL49653 in KK-Ay mice on high-fat diet, in terms of plasma glucose, body weight gain and interscapular brown adipose tissue (IBAT) weight. JTP-426467 alone inhibited body weight gain and decreased plasma leptin level in KK-Ay mice. CONCLUSIONS: JTP-426467 acted as a pure and potent PPARgamma antagonist in vitro. Interestingly, JTP-426467 completely antagonized the effects of PPARgamma agonist BRL49653 in an obese diabetic model. JTP-426467 may be a useful tool for the study of PPARgamma in biological and physiological function.

Adipocytes↗
PubMed2006

[Surgical fixation for flail chest].

Flail chest occurs by blunt chest trauma and is associated with pulmonary contusion, atelectasis, pneumothorax, hemothorax, and respiratory failure. Because of its severity, it may need internal pneumatic stabilization or surgical fixation. Some patients do not need the internal stabilization and are observed conservatively. Some of these patients, however, increase the flail after palliating the pain and getting up. These patients show inefficient ventilation and surgical fixation is needed. The operation should be performed after the improvement of pulmonary contusion. In this paper, we presented 2 patients who showed such course and clarified the surgical methodology.

Aged↗
PubMed2005

Heart-type fatty acid binding protein is a novel prognostic marker in patients with non-ischaemic dilated cardiomyopathy.

OBJECTIVE: To determine whether concentrations of heart-type fatty acid binding protein (H-FABP) measured before hospital discharge predict critical cardiac events in patients with idiopathic dilated cardiomyopathy (DCM). PATIENTS: 92 consecutive patients with DCM were enrolled and followed up for four years. MAIN OUTCOME MEASURES: Serum concentrations of H-FABP, brain natriuretic peptide (BNP), cardiac troponin T before hospital discharge and survival rate. RESULTS: 23 patients died of cardiac causes, received a left ventricular assist device or underwent heart transplantation during the four-year follow up. Univariate analyses showed that New York Heart Association functional class, heart rate, ejection fraction, serum H-FABP and plasma BNP were significant variables. According to multivariate analysis, serum H-FABP and plasma BNP concentrations were independent predictors of critical cardiac events. Cardiac troponin T before hospital discharge was not a predictor. The area under the receiver operating characteristic curve for death from critical cardiac events was similar between H-FABP and BNP. Patients with an H-FABP concentration at or above the median (> or = 5.4 ng/ml) had a significantly lower survival rate than those below the median, according to analysis by log rank test (p < 0.0001). When combined with BNP concentration at or above the median (> or = 138 pg/ml), H-FABP below the median predicted the worst prognosis among the combinations. CONCLUSIONS: The concentration of serum H-FABP before discharge from hospital may be an independent predictor for critical cardiac events in DCM.

Biomarkers↗
PubMed2005

Effects of repeated maternal stress on FOS expression in the hypothalamic paraventricular nucleus of fetal rats.

The effects of repeated prenatal stress with different severity (restraint and immobilization) on Fos expression in the maternal and fetal hypothalamic paraventricular nucleus (PVN) were examined in rats. Acute stress treatment was performed for 30 min on gestational day 21, and repeated stress treatment for 30 min daily for 5 days from gestational days 17-21. In the parvocellular region of the maternal PVN, the stress-induced increases in the number of Fos-immunoreactive neurons were smaller in the repeated stress groups than the acute stress groups, indicating an adaptation of Fos expression to repeated stress. The attenuated Fos expression observed in the maternal PVN following repeated mild stress did not occur in the fetal PVN. In contrast, repeated immobilization stress caused a much smaller increase in Fos expression in the fetal PVN than did acute immobilization stress. The reduced Fos expression in the fetal PVN following repeated severe stress was thought to be due to cell death, since the fetal PVN in the chronic immobilization group revealed a reduction in the total number of cells and an increase in the number of apoptotic cells. In the female but not male fetuses, repeated restraint stress induced a significant increase in the number of apoptotic cells in the PVN. These findings suggest that the fetal PVN shows no adaptation of Fos expression to repeated maternal stress, but great vulnerability to cell death, including apoptosis. In addition, stress-induced apoptosis may more easily occur in the fetal PVN in females than males.

Acute Disease↗
PubMed2005

Serum prorenin levels and diabetic retinopathy in type 2 diabetes: new method to measure serum level of prorenin using antibody activating direct kinetic assay.

AIM: To investigate the serum levels of prorenin and its correlation with the severity of diabetic retinopathy (DR). METHODS: 248 patients with diabetes and 108 control subjects were divided into four groups: no-DR (n = 146), no proliferative diabetic retinopathy (no-PDR) (n = 78), PDR (n = 24), and controls (n = 108). Serum levels of prorenin from all subjects were measured using the new antibody activating direct kinetic (AAD-PR) assay. The serum prorenin levels were compared among the groups. RESULTS: The serum levels of prorenin in the control, no-DR, no-PDR, and PDR groups, respectively, were 109.1 (66.1), 194.6 (160.4), 271.5 (220.3), and 428.4 (358.4) pg/ml (mean (SD)). Prorenin in the PDR group was remarkably high compared with the control and no-DR groups (p<0.0001) and with the no-PDR group (p = 0.002). Serum levels of prorenin increased with increasingly severe retinopathy. No correlation was found between the prorenin level and the duration of disease or HbA(1c). CONCLUSIONS: The serum levels of prorenin in patients with PDR were found to be markedly high using the AAD-PR assay. Increased levels of prorenin in diabetes may have an important role in the pathogenesis of DR.

Antibodies↗
PubMed2005

Increased E2F-1 expression via tumour cell proliferation and decreased apoptosis are correlated with adverse prognosis in patients with squamous cell carcinoma of the oesophagus.

BACKGROUND: The retinoblastoma (Rb) pathway, which governs cell cycle progression, is frequently genetically altered in cancer, causing deregulated expression of the E2F-1 transcription factor, which promotes DNA synthesis and cell cycle progression. Recent studies show that E2F-1 also participates in apoptosis induction in a p53 dependent or independent manner. Despite its crucial role and paradoxical effects on cell turnover, the function of E2F-1 in human cancer is unclear. AIMS: To evaluate E2F-1 expression using immunohistochemistry in 43 surgically resected oesophageal squamous cell carcinoma (OSCC) specimens. METHODS: This study analysed the association of E2F-1 with tumour cell proliferation and apoptosis and the upstream regulators modulating these processes, and its impact on patient outcome. Tumour cell proliferation and apoptosis were assessed as percentage of MIB-1 positive or apoptotic cells (MIB-1 labelling index (MI) and apoptotic index (AI)), respectively. RESULTS: Entire specimens showed abnormal expression of one or more upstream regulators of pRb/E2F-1. Although E2F-1 positivity was not associated with the expression of upstream regulators, it showed a linear and positive correlation with MI but not AI. Patients with high MI, low AI, or high E2F-1 positivity had significantly shorter recurrence free survival. By multivariate analysis, high MI and low AI were independently associated with recurrence free survival, but E2F-1 was not. CONCLUSIONS: Increased cell proliferation and decreased apoptosis are associated with adverse prognosis in patients with OSCC. Although E2F-1 remains a controversial prognostic factor, its expression was closely associated with tumour cell proliferation and might influence clinical outcome, mainly via cell cycle progression.

Adult↗
PubMed2005

Clinical effects of Lactobacillus acidophilus strain L-92 on perennial allergic rhinitis: a double-blind, placebo-controlled study.

Studies in animals have suggested that lactic acid bacteria alleviate allergic diseases, however, little information is available on their clinical effect on allergy in humans. Thus, we examined the efficacy of orally administered Lactobacillus acidophilus strain L-92 (L-92) on perennial allergic rhinitis. In a randomized, double-blind, placebo-controlled clinical trial, 49 patients with perennial allergic rhinitis were randomized to receive either 100 mL of heat-treated fermented milk containing L-92 (n = 25) or acidified milk without lactic acid bacteria (placebo; n = 24) for 8 wk. The severity of symptoms was evaluated based on the changes in the scores of clinical symptoms. Oral administration of milk fermented with L-92 resulted in a statistically significant improvement of nasal symptom-medication scores. Ocular symptom-medication scores of patients in the L-92 intervention group tended to improve compared with those in the placebo group. In addition, clear decreases of the scores of swelling and color of the nasal mucosa were observed in the L-92 intervention group at 6 and 8 wk after the start of ingestion of fermented milk. There were no significant differences in serum antihouse dust mite immunoglobulin E levels nor in T helper type 1/T helper type 2 ratio between the 2 groups. These results suggest that oral administration of L-92 can alleviate the symptoms of perennial allergic rhinitis, however, statistically significant changes were not shown in blood parameters.

Animals↗
PubMed2005

Dynamics of airborne pollen particles from inhalation to allergic reaction in the nose.

BACKGROUND: Pollinosis is common worldwide, and has been frequently studied. However, the intranasal dynamics of pollen grains have not yet been documented. The purpose of this study is to elucidate for the first time the dynamics of Japanese cedar pollen (JCP) in the human nose at consecutive steps from inhalation to allergic reaction together with release of Cry j 1 (a major allergenic component of JCP) in the nose. METHODS: A personal sampler collected airborne pollens at head height outdoor on the street, while intranasal pollens after natural or experimental inhalation were collected by irrigation with 200ml saline. Cry j 1 in the supernatant after in vitro incubation with phosphate buffered saline or lavage was determined by enzyme-linked immunoassay. RESULTS: Head-height pollen was 183.0 +/- 43.1/300L/h, with 99% of the inhaled pollens deposited on the nasal surface. Eighty eight% of the inhaled pollen was transported to the out-side of the nose by ciliary function within 3 hours. During this process, considerable amounts of Cry j 1 were released in the nose reaching its plateau within 30 min. When the number of pollen deposited exceeded more than approximately 65 particles, symptoms may occur, leading presumably up to a 74% reduction of the intra-nasal pollen. CONCLUSION: The majority of inhaled airborne pollens was deposited on the nasal mucosal surface and moved out from the nose by mucociliary transportation. During this process, when allergenic substances are released up to a critical concentration, allergic reactions occur leading to expelling of pollen from the nose followed by subsiding of the symptoms.

Adult↗
PubMed2005

[Optimal treatment of intrathoracic extramedullary hematopoiesis resembling posterior mediastinal tumor; report of a case].

Intrathoracic extramedullary hematopoiesis is a rare condition accompanying chronic hematologic disease. We present a case of chronic gastric ulcer in which a posterior mediastinal mass was diagnosed as extramedullary hematopoiesis. We underwent video-assisted thoracoscopic resection safely and successfully. This procedure is relevant and safety procedure for differential diagnosis of patients who have chronic anemia with asymptomatic intrathoracic tumors.

Aged↗
PubMed2004

Phonon dispersion curves of a BC3 honeycomb epitaxial sheet.

The entire phonon-dispersion curves along the Gamma-M direction of a BC3 honeycomb sheet have been determined both experimentally and theoretically for the first time. Most of the observed curves agreed with the theoretical ones calculated on the basis of ab initio theory. From the stretching force constants of the nearest-neighbor C-C and B-C bonds, together with that of the B-B bond, we clarified the characteristic feature of the C-C and B-C bonds. From the experimental and theoretical results, we discussed the possibility of high T(c).

Journal Article↗
PubMed2004

Opposite morphological responses of partially denervated cortical serotonergic and noradrenergic axons to repeated stress in adult rats.

We examined plastic changes in serotonin (5-HT) axons following repeated stress in the adult rat brain, and compared stress-induced changes between 5-HT and noradrenaline (NA) axons. We locally injected the specific neurotoxin to 5-HT axons or to NA axons into the frontal cortex to cause partial denervation. The animals were mildly restrained from 1 day after the neurotoxin injection and this stress was repeated daily for 20 min during the first 2 days and for 40 min during the next 11 days. On the fourteenth day after injection, the brains were removed to visualize 5-HT and NA axons by immunohistochemistry. Repeated stress did not significantly alter the denervation area of 5-HT or NA axons, but the density of 5-HT axons was increased whereas that of NA axons was decreased in cortical regions outside the denervation site. In addition, the expression of brain-derived neurotrophic factor (BDNF) was increased in cortical regions where the 5-HT axon density was increased in response to stress. These results suggest that repeated stress causes opposite changes in the morphology of partially denervated 5-HT and NA axons in the cerebral cortex. The stress-induced increase in BDNF expression may contribute to 5-HT axon sprouting following repeated stress.

5,6-Dihydroxytryptamine↗
PubMed2004

Radionuclide imaging metabolic activity of brown adipose tissue in a patient with pheochromocytoma.

We describe a patient with extra-adrenal pheochromocytoma and high plasma norepinephrine levels. Radionuclide images of this patient obtained using (18)F-fluorodeoxyglucose and (123)I-metaiodobenzylguanidine revealed bilateral tracer accumulation in the shoulder and lower neck. The regions of radiotracer uptake corresponded to the location of human brown adipose tissue (BAT). Excessive sympathetic stimulation by high circulating catecholamine concentrations augmented the metabolic activity and tracer uptake in the BAT. This study showed that radionuclide imaging can noninvasively visualize human BAT in terms of metabolic and functional activity.

Adipose Tissue, Brown↗
PubMed2004

Effects of modification at the fifth residue of mu-conotoxin GIIIA with bulky tags on the electrically stimulated contraction of the rat diaphragm.

Mu-conotoxin GIIIA, a peptide toxin from the cone snail, blocks muscle-type sodium channels. Thr-5 of mu-conotoxin GIIIA, located on the opposite side of the active site in the globular molecule, was replaced by Cys to which the bulky tags were attached. The tagged mu-conotoxin GIIIA derivatives, except for the phospholipid-tagged one, exerted the biological activity with a potency slightly weaker than natural mu-conotoxin GIIIA. When the biotinylated tags of various lengths were added, the presence of avidin suppressed the action of the biotinylated toxins of <4 nm, but not with 5 nm. The bulky biotinylated tags are useful as a caliper to measure the depth of receptor sites in the channels.

Amino Acid Sequence↗
PubMed2003

In situ photoemission study of the room temperature ferromagnet ZnGeP2:Mn.

The chemical states of the ZnGeP(2):Mn interface which shows ferromagnetism above room temperature have been studied by photoemission spectroscopy. Mn deposition on the ZnGeP2 substrate heated to 400 degrees C induced Mn substitution for Zn and then the formation of metallic Mn-Ge-P compounds. Depth profile studies have shown that Mn 3d electrons changed their character from itinerant to localized along the depth, and in the deep region, dilute divalent Mn species (<5% Mn) was observed with a coexisting metallic Fermi edge of non-Mn 3d character. The possibility of hole doping through Mn substitution for Ge and/or Zn vacancy is discussed.

Journal Article↗